Prof. David Howey: The Charging Curve // + Does LFP 'Like' to be Charged to 100%?

Welcome back everyone, I'm Jordan Geesege and this is The Limiting Factor. I've been running this channel for about 4 years now and one of the biggest knowledge gaps for me from a software perspective was what determines how fast a battery charges. Now I finally found someone who I think can help shed some light on the topic. David Howie of the University of Oxford who specializes in modeling and managing EV and grid storage power systems. Before we begin, a special thanks to my Patreon supporters, YouTube members and Twitter subscribers as well as RebellionAir.com. They specialize in helping investors manage concentrated positions. RebellionAir can help with covered calls, risk management and creating a money master planned from your financial first principles. Hi David, it's nice to finally have a discussion with you.

大家欢迎回来，我是乔丹·吉斯格，这里是《限制因素》。我已经经营这个频道大约有4年了，而我从软件的角度来看，最大的知识空白之一是什么决定了电池充电的速度。现在我终于找到了一个我认为可以为我们解释这个话题的人。他就是牛津大学的大卫·豪伊，专门从事电动汽车和电网储能系统的建模与管理。在我们开始之前，特别感谢我的Patreon支持者、YouTube会员和Twitter订阅者，以及RebellionAir.com。他们专门帮助投资者管理集中的头寸。RebellionAir可以帮助您进行认购期权、风险管理并根据您的金融第一原理制定一个理财计划。嗨，大卫，很高兴终于和您进行讨论。

I've been looking forward to this interview for quite some time. It's great to meet you, Jordan and yeah, nice to chat about batteries. So let's start with the basics. How is the state of charge and a battery determined in, for example, an electric vehicle? Great, yeah, it's a great question, you know, very fundamental question. I've been telling people to be worrying about for a long time actually since batteries and consumer electronics came together 20, 25 years ago. And I guess the short answer is wouldn't it be great if you could just stick a sensor in and measure the state of charge directly? And in some types of batteries you can, right? So let us battery, you can actually just sample the electrolyte, measure the density of the electrolyte and get the state of charge from that. Back in the old days, that's what people used to do, the very old days. Lithiumine, it's not so straightforward.

我已经期待这次采访很长时间了。很高兴见到你，乔丹，是的，很高兴聊一聊电池。那么，让我们从基础知识开始。例如，在电动车中，如何确定电池的电荷状态？是的，这是一个很好的问题，你知道，非常基础的问题。实际上，我很久以前就告诉人们要担心这个问题，自从电池和消费电子产品结合在一起20，25年前。我想简短的回答是，如果你能直接插一个传感器测量电池的电荷状态会很好，对吧？在一些类型的电池中，实际上是可以的，对吧？例如铅酸电池，你其实可以只取样电解液，测量电解液的密度，从中得到电池的电荷状态。在很久以前，人们就是这样做的，很早以前。而对于锂电池来说，情况就没那么简单了。

And if you've got an application where the current is quite small, what we call the C-rate, I'm sure you know what that is, but you know, the current is pretty small, you're just charging the battery for many, many hours, maybe like your mobile phone. Then to an approximation, you can just measure the voltage of the battery, right? Something a little bit on which lithium-ion chemistry you are using, okay? But as soon as you start doing things with more current, the electric car, maybe you like driving fast and accelerating, get lots of spikes in the current and this causes the voltage to jump up and down and so that method kind of becomes less good and we have to start compensating for all these jumps.

如果你有一个电流非常小的应用程序，我们称为C率，我相信你知道这是什么意思，但是，你知道，电流很小，你只是充电了很多小时的电池，也许就像你的手机。在这种情况下，你可以大致测量电池的电压，对吧？取决于你使用的锂离子化学。但是一旦你开始使用更多电流，比如电动汽车，也许你喜欢快速驾驶和加速，电流会出现很多波动，这会导致电压上下跳动，这种方法就会变得不够好，我们就得开始补偿这些波动。

And so, you know, the method we use in the lab, the sort of gold standard method if you like, to measure safety charge, is called Coulomb counting, which again, I'm sure you and many listens will have heard of and this is what it says on the tin. So basically, you count the number of electrons going through your external circuit, which sounds very complicated, but it just means you have a current sensor and you take the measurements of current instantaneously and you just add them up over time. Mathematically, we integrate the current. And why this works is because, you know, in a battery that is degrading very slowly compared to how you are using it second by second, there's a correspondence between the number of electrons going through the external circuit and the number of ions going across the battery internally.

因此，你知道，在实验室中我们使用的方法，如果你喜欢的话可以称之为黄金标准方法来测量安全电荷，就是所谓的库仑计数，我相信你和许多听众可能已经听说过了，这就是它的含义。基本上，你要计算通过外部电路的电子数量，听起来很复杂，但其实只是意味着你有一个电流传感器，实时测量电流并随时间累加。从数学上讲，我们对电流进行积分。这个方法之所以有效，是因为，你知道，与你每秒使用它的方式相比，电池的衰减非常缓慢，外部电路中通过的电子数量与电池内部离子穿越的数量之间存在对应关系。

And so it's like bookkeeping or accounting, we can basically, you know, indirectly count how many ions moving across the battery by counting the electrons in the external circuit. And in some ways, this is the only way we can measure the state of charge. So it's actually kind of a, it's kind of a complicated issue because we're always having to kind of operate blindfold if I can put it like that. And a lot of the effort in battery management systems over the last 10, 15 years has been around how do you do this, but in a real application where the current sensor might not be super accurate and you might have a very dynamic driving profile.

因此，就像簿记或会计一样，我们基本上可以通过计算外部电路中的电子数量来间接计算电池中移动的离子数量。在某种程度上，这是我们测量电池充电状态的唯一方法。所以实际上这是一个有点复杂的问题，因为我们总是不得不像挡住眼睛一样进行操作。在过去的10年到15年里，电池管理系统中的很多努力都集中在如何在一个真实应用中进行这种操作，其中电流传感器可能不够精确，而且驾驶特性可能非常动态。

And in order to do that, you need to bring models into the BMS. And those models are basically used to correct for errors in the current sensor and noise and stuff like that. Because when you're adding up measurements of current over time, you're also adding up any errors that creep in and that has to be reset, if you like. And so that's the problem with Coulomb counting. You can never measure the current perfectly. So you get this drift issue that you have to correct before. Okay, so there's, it sounds like there's, there's a gold standard way of measuring the state of charge, but so you can do it through Coulomb counting or voltage. What I'm picking up is that you're always, it's always a best estimate and a best guess as to what that state of charge actually is in reality. We kind of have to use these other variables as proxies to understand what the state of charge is.

为了做到这一点，您需要将模型引入电池管理系统中。这些模型基本上用于校正当前传感器和噪音等方面的错误。因为当您随着时间累加电流测量时，也会累加任何可能出现的误差，这些必须被纠正。 这就是库仑计数的问题。永远无法完美测量电流。因此，您将面临这种漂移问题，必须在之前进行校正。 好的，听起来有一种衡量电池电荷状态的标准方法，您可以通过库仑计数或电压来实现。我理解的是，您始终需要估算和猜测电池的电荷状态。我们必须使用其他变量作为替代品来理解电池的电荷状态。

Yeah, that's correct. Without getting into too much detail, you know, what we're trying to measure is the state of lithiation of the electrodes in a lithium ion battery. And we could say that voltage is a way of measuring that, but only at equilibrium. And unfortunately, and what that really means is we have to discharge the battery really slowly under very controlled conditions charged very slowly. And by slowly, I mean really slowly, you know, maybe over 10 hours, 20 hours, 50 hours, something like that.

是的，没错。不用深入细节，你知道，我们试图测量的是锂离子电池电极的锂化状态。我们可以说，电压是一种测量的方式，但只适用于平衡状态。不幸的是，这意味着我们必须以非常缓慢的速度放电电池，在非常受控的条件下缓慢充电。当我说缓慢时，我的意思是非常缓慢，可能需要10小时、20小时、50小时这样的时间。

So it's just not practical outside of lab to do these very, very slow measurements and count all the Coulombs in a very sort of controlled way. And that's why we need all of these engineering approaches to kind of bridge the gap between that and something that actually works second by second in a real vehicle. So for instance, an electric vehicle, I've seen a number of different ways reported to estimate the state of charge. What is typically the way that they estimate the state of charge in a vehicle rather than say in the lab? Is it the voltage or?

因此，除了在实验室中进行这些非常缓慢的测量并以非常受控制的方式计算所有库仑之外，在实际的车辆中做起来并不实际。这就是为什么我们需要所有这些工程方法来填补这个差距，使其在实际车辆中能够每秒正常工作。例如，对于电动车，我已经看到了几种不同的方式来估计电池的充电状态。通常情况下，他们是如何估计车辆的充电状态的，而不是在实验室中呢？是通过电压还是其他方式？

Yeah. So what you do, well, let me just take a step back. So you could argue that in a phone, you could measure the voltage, right? Maybe for various reasons, maybe you'd go beyond that, but you could argue that it's slow enough charge, sorry, discharge, not charge that you just measure the voltage. In a vehicle, what you do is you would do this Coulomb counting technique. So you would have a current sensor, you measure the current from the pack, you'd add that up second by second over time. You need to know the initial condition, you need to know the starting point, otherwise you know, is it full or empty? Where are you starting from? It's all relative to where you start.

是的。那么，你做的事情，让我先退一步。你可以争论说在手机中，你可以测量电压，是吧？也许出于各种原因，也许你会超越这个，但你可以争论说它充电速度慢到足以只测量电压。在车辆中，你所做的是使用库仑计数技术。所以你会有一个电流传感器，你会测量电池组的电流，然后逐秒累加起来。你需要知道初始条件，你需要知道起始点，否则你知道的是满还是空？你从哪里开始？一切都是相对于你的起点。

But then what you do is you would also be measuring the voltage. And we know that although the voltage doesn't absolutely, accurately tell us the state of charge, it's in the right territory, right? I mean, a lithium-ion battery voltage, okay, let's take an MC type chemistry. It's very, you know, it's very between say 2.7, 4.2 volts, something like that. And so if the voltage is nearer to 4 volts, you'd expect the SSC to be higher and vice versa.

但是，接下来你要做的是你也会测量电压。我们知道虽然电压并不能绝对地准确告诉我们充电状态，但它处于正确的范围，对吧？我的意思是，以锂离子电池电压为例，好吧，让我们以MC型化学结构为例。它通常在2.7到4.2伏之间波动。所以如果电压接近4伏，你会希望SOC更高，反之亦然。

And so what we do is we build models, which basically tell us what the voltage drops inside the battery are. And then we can take the measure voltage and sort of run it through a model and work out what the sort of theoretical open circuit voltage would have been under no load conditions, everything equated. And then compare that to the state of charge that we get from counting up the current. We sort of bring those two things together in a clever way. And that gives us kind of the best blend of the two things. And that also allows you to reset the errors from the coolant counting. Does that make sense?

所以我们做的是建立模型，基本上告诉我们电池内部的电压下降情况。然后我们可以测量电压，通过模型计算出在零负载条件下的理论开路电压，将一切设为平等。然后将其与通过计算电流得到的电荷状态进行比较。我们以巧妙的方式将这两个方面相结合。这样就能得到两者的最佳结合。这还可以让你重新设定冷却液计数的误差。这样讲清楚了吗？

Yes. I won't dig any further because it sounds like there's a lot of depth and there's a lot of places we could go with that. But I think that's a good explanation for now. For me, it raises the question. Different batteries have different voltage curves. For instance, LFP has a very narrow voltage range and a high nickel chemistry has a very broad voltage range. So do each of those pose their own unique challenges or is one easier to deal with than the other?

是的。我不会再深挖了，因为听起来这个问题很有深度，我们可以从很多角度讨论。但我认为目前这样解释已经足够了。对我来说，这引发了一个问题。不同的电池有不同的电压曲线。例如，磷酸铁锂电池有非常窄的电压范围，而高镍化学电池有非常广泛的电压范围。那么，它们各自是否带来了独特的挑战，或者其中一个比另一个更容易处理？

They absolutely have unique challenges. And you've hit the nail on the head that LFP is challenging for SSC estimation. And the reason for that is because the voltage is quite flat as a function of SSC. So at higher or low voltage, you know, you get some variation. You have this kind of sigmoidal shape in voltage versus SSC. So if you go to the very top or the very bottom of the curve, great. You've got a good sort of indication of SSC in terms of the voltage. But if you're somewhere in the middle, say between 20 and 80%, that's a problem. You know, the voltage is super flat. It's great if you're a power electronics engineer and you're building a power converter because you've got a nice constant voltage power source. That's what you want.

他们绝对面临着独特的挑战。你说得一点不错，LFP对于估算SSC很具挑战性。这是因为电压在SSC方面是相当平的。所以在较高或较低电压下，你会得到一些变化。电压与SSC之间形成了一种S形曲线。所以如果你在曲线的顶端或底端，很好，你通过电压得到了SSC的良好指标。但如果你处于中间位置，比如在20%到80%之间，那就是一个问题。你知道，电压非常平稳。如果你是一名功率电子工程师，正在建造功率转换器，这是很好的，因为你有一个稳定的电压电源。这正是你想要的。

But if you're trying to work out from the voltage, what the SSC is, there's a huge ambiguity. The voltage changes are really small. And there's an additional problem with NFP, which is something called hysteresis, which is similar if people have heard of magnetic materials, maybe you remember from school physics or whatever that you get, this BH curve for a magnetic material.

但是，如果你试图通过电压来确定SSC是什么，就会有很大的歧义。电压变化非常小。此外，还有一个有关NFP的问题，那就是所谓的磁滞效应，这类似于如果有人听说过磁性材料，也许你还记得在学校物理课上所学到的BH曲线。

And what it comes down to is with lithium ion phosphate, you get a different voltage depending on whether you're charging or discharging. So there's a gap between the charge and discharge voltage at zero current. So this gap kind of doesn't go away, even if you take the current away and wait for a while. And you absolutely have to take this into account. It makes quite a big difference. And if you don't take it, if you just assume you have one voltage, it's going to be massively ambiguous. So you are in the mid range.

最终问题在于磷酸锂离子电池，在充电和放电时会产生不同的电压。因此，在零电流时，充电电压和放电电压之间存在一个间隙。即使将电流移除并等一段时间，这个间隙也不会消失。你绝对必须考虑到这一点，因为这会造成相当大的差异。如果你不考虑这一点，仅仅假设只有一个电压值，那么结果将会非常模棱两可。因此你处于中间范围。

Yeah. All right. And you mentioned magnetism there. I was very weak in physics when I was in school. I was more biology. But does that have to do with because LFP is a magnetic material? Is that what? No, no, sorry. Yeah, apologies. That's not the situation. I was just, it's just analogous to the way that magnets behave. You have this thing called hysteresis. But so put magnets out of your mind. It's not related to magnetism. But what it really means, if I could draw a picture for you, what you would see is that I get a different relationship between voltage at very slow rates, open circuit rates, depending on whether I'm charging or whether I'm discharging. So I kind of go up one curve when I'm charging and then I come down to slightly different curve when I'm discharging. And there's a gap between those two curves. So if I gave you an LFP battery and I said, I didn't tell you anything about how to be used. But I said, it hasn't been used for the last few hours and you did a voltage measurement and I asked you what's the state of charge. It would be very difficult for you to tell me absolutely accurately what that was because you don't know whether it's been charging or discharging.

是的。好的。你提到了磁性。我在学校时物理很差。我更了解生物。但这与LFP是磁性材料有关吗？是这样吗？不，不，抱歉。不是这种情况。我只是，这只是类似于磁铁的行为方式。你有这个叫做磁滞的东西。但是把磁铁想出你的脑海。这并不涉及磁性。但它真正意味着的是，如果我能为你画一幅图，你会看到在非常慢的速率、开路速率下，电压之间有一个不同的关系。取决于我是在充电还是在放电。所以当我充电时，我会沿着一个曲线上升，然后当我放电时会沿着稍微不同的曲线下降。两条曲线之间有一个间隙。所以如果我给你一个LFP电池，我说，我没有告诉你如何使用它。但我说，它在最近几个小时内没有使用，你做了一个电压测量，我问你电量状态是什么。你可能很难绝对准确地告诉我那是什么，因为你不知道它是在充电还是在放电。

So you don't know which of these two curves you're on. And so this adds a complication because then the battery management system has to keep track of the history and basically use, in a clever way, some historical data about whether you come down or you're going up. And you can imagine if you don't do a full charge discharge, then interesting things happen. So say I go to 50% and then I discharge by 10%. I get like a small version of this gap in between.

因此，你不知道你处于这两条曲线中的哪一条。这就增加了一个复杂性，因为电池管理系统必须跟踪历史记录，并在一定程度上，以巧妙的方式利用一些关于你是下降还是上升的历史数据。你可以想象，如果不进行完全充电和放电，会发生一些有趣的事情。比如我将电池充到50%，然后放电10%。我会在中间得到一个小版本的这个间隙。

So it makes a little sort of eye shape. You know what I mean? Yeah. You know, I understand people are not watching. You have to imagine basically I'm plotting with my hands on the vertical axis of function which is open server voltage on the horizontal axis, it's state of charge. And one curve which kind of goes up a bit and then along and then up again and I have another version of that curve and there's a gap in the flat region in the middle of between the two curves. And what I can do after when I publish the video, I can include an image.

这样就形成了一个有点像眼睛的形状。你知道我在说什么吧？是的。你知道，我知道大家都在看。你必须想象，基本上我是用手在垂直轴上绘制函数，这是开放服务器电压，水平轴上是充电状态。有一条曲线有点向上，然后水平，然后再上升，我有另一个版本的那条曲线，并且在两条曲线之间的中间平坦区域有一个间隙。在我发布视频后，我可以添加一张图片。

So if you have a good chart of that, I get it when I put the video together, absolutely. Great. And you're saying that's something that's more of an issue with LFP than with a high nickel chemistry? Is that right? Yeah, yeah, absolutely. So there's really two issues with that. One is this hysteresis issue. So I need a different voltage curve depending on whether I'm charging or discharging, even it really very slow rates. So this gap remains even if I remove the current. And the second issue of LFP is just the fact that the change in voltage is very flat as a function of state of charge between sort of 20 and 80%.

所以如果你有一个很好的图表，当我把视频编辑好时，我就能搞清楚了，没问题。好的。你说这是LFP比高镍化学成分更严重的一个问题？没错吧？是的，完全是的。所以有两个问题。其一是这个滞后问题。所以根据我是在充电还是放电，我需要一个不同的电压曲线，即使是在非常慢的速率下。所以即使我移除电流，这个差距仍然存在。LFP的第二个问题就是电压随着充放电状态在20%到80%之间几乎没有变化。

So that means I don't get much information from the voltage about where the SSC is. All right, so if you were a hardware engineer, you'd like the fact that LFP has a very flat voltage curve. But if you're a software engineer, it's more of a challenge because you have all these other variables, all these kind of demons in the machine. Yeah, yeah, yeah. And then with a high nickel chemistry, the software is easier to look after because there's not these strange variables going on to where you have to do more work to estimate the state of charge. But the hardware engineers might not like it as much because there's this huge difference in voltage over the course of charge and discharge cycle. Is that right then? Yeah, yeah, that's a great summary, Jordan. Yeah, absolutely. So your power converter is going to have to be a little bit more carefully designed for a wider voltage range in a chemistry that has a wider voltage range. And actually going slightly off piece from this discussion, a good example of a challenging chemistry there is sodium ion because there's quite a wide voltage range.

这意味着我无法通过电压获取关于SSC位置的太多信息。好的，所以如果你是一名硬件工程师，你会喜欢LFP具有非常平稳的电压曲线。但如果你是一名软件工程师，这更多是一个挑战，因为你有所有这些其他变量，所有这些在机器中的魔鬼。是的，是的，是的。然后，对于高镍化学，软件更容易管理，因为没有这些奇怪的变量，你必须做更多工作来估计电荷状态。但硬件工程师可能不会那么喜欢，因为在充电和放电周期中，电压会有很大的差异。那么是这样吗？是的，是的，这是一个很好的总结，乔丹。是的，绝对是。因此，您的电源转换器将需要对具有更宽电压范围的化学物质进行更仔细的设计。实际上，稍微偏离这个讨论，一个具有挑战性的化学物质的一个很好的例子是钠离子，因为其具有相当宽泛的电压范围。

Another good example is that there's a supercapacitor because if you really want to extract all the energy from a supercapacitor, you have to go down to zero volts. And so it's hard to make a DC or a DC to AC converter that has a huge voltage range. So at the end of the day, if I have a supercapacitor connected to a power converter, there'll be a lower voltage limit beyond which I don't want to go any lower. So I'm going to miss out on some energy at very low voltages. All right. And I actually had a question about sodium ion earlier and that answers part of it.

另一个很好的例子就是超级电容器，因为如果你真的想要从一个超级电容器中提取所有的能量，你必须降至零伏特。所以制造一个具有巨大电压范围的直流或直流到交流变换器是很困难的。因此，最终，如果我将一个超级电容器连接到电源变换器，将会有一个较低的电压限制，超过这个限制我不想再降低电压。所以在非常低的电压下我会损失一些能量。好的。早些时候我有一个关于钠离子的问题，这部分回答了我的疑问。

So on the hardware and sodium ion has challenges because there's a broad voltage range. Now somebody also mentioned to me that it besides the broad voltage range, it also has a high voltage hysteresis or a high hysteresis. Yeah. Correct? Yeah, that is right. So you're sort of getting the same problems you had with LFP with sodium ion. Yeah. Correct. So sodium ion, it's LFP and nickel have positives and negatives where sodium ion in both cases, hardware and software, it's more difficult to deal with, but not insurmountable, just extra challenges. Yeah. I think that's a good summary. So with sodium ion, there's definitely a voltage hysteresis and you need a fairly wide range of voltages for your power converter to really get the most out of the cells. I mean, these are sort of solvable problems if I can say that. They make our lives more interesting as researchers. Oh, sorry.

在硬件和钠离子方面存在挑战，因为电压范围很广。现在有人还告诉我，除了宽广的电压范围外，它还具有高电压滞后或高滞后。是的。对吗？是的，没错。所以，你在处理钠离子时遇到了与LFP相同的问题。是的。没错。因此，钠离子在硬件和软件方面都更难处理，但并非难以克服，只是额外的挑战。是的。我认为这是个不错的总结。所以，对于钠离子电池，肯定存在电压滞后问题，你需要一个相当宽范围的电压，才能真正充分利用电池。我是说，这些问题有解决方法。他们让我们作为研究人员的生活更有趣。啊，抱歉。

One of the things that's interesting from a sort of scientific point of view is why does this hysteresis happen in these different chemistries? And is it that we could sort of think of hysteresis in two different ways? Is it a thing that is always there? So if I remove the current and wait for forever, you know, does it stay or not forever, but you know, for a week, does the voltage gap stay there? Or if I wait for a day or two, does it gradually come back to the middle? And I think some materials like graphite, it could be more like the second one, right, where if you wait long enough, it will kind of equilibrate. Although on a practical level, that long could be quite long, right? And actually, so we've seen some data where we can get hysteresis from graphites and it gets worse at lower temperatures as well. So actually, I think some of these problems would manifest even if you just had like NMC graphite cell, there's a little bit of hysteresis from the graphite, at least on the time scales that we're interested in when we're driving our cars over a few hours, right? Yeah, we could wait two days, but I'm not sure we're going to do that just to get a BMS to be accurate. Yeah, we have practical real-world application. Yeah.

从一种科学的角度来看，有趣的事情之一是为什么不同的化学反应会出现这种迟滞效应？我们可以以两种不同的方式思考迟滞效应吗？它总是存在吗？所以，如果我去掉电流并等待很久，它会保持不变吗？或者如果我等一两天，它会慢慢恢复到中间状态吗？我认为有些材料，比如石墨，可能更像是后一种情况，如果等待足够长时间，它会达到平衡。尽管在实际水平上，这段时间可能相当长。实际上，我们已经看到一些数据，我们可以从石墨中得到迟滞效应，而且在较低温度下情况会更糟。所以我认为即使只是使用NMC石墨电池，一些这些问题也会显现出来，至少在我们驾驶汽车几个小时的时间尺度上，我们所感兴趣的时间尺度上会有一些石墨的迟滞效应。是的，我们可以等两天，但我不确定我们会这样做，只是为了让BMS准确。是的，我们有实际的现实应用。

Now, when somebody charges their electric vehicle, so let's move on to the next aspect of this, we've just looked at how the state of charge is determined and the variables around that, which is we could do an hour on that. But the next factor is when somebody charges their vehicle, there's a charging curve that determines how fast the vehicle charges. Can you explain how that charging curve is created and how the vehicle determines the charge curve when it charges because that charging curve can change under different conditions. So how are those, I guess, that set of charging curves that manages battery charging, how does that make? Right.

现在，当有人给他们的电动汽车充电时，让我们继续讨论这个话题的下一个方面。我们刚刚看了电池充电状态是如何确定的以及相关的变量，这部分内容我们可以花上一个小时讲。接下来的因素是当有人给他们的汽车充电时，会有一个充电曲线来确定车辆的充电速度。您能解释一下这个充电曲线是如何创建的吗，以及车辆在充电时如何确定充电曲线，因为这个充电曲线在不同条件下会发生变化。那么，管理电池充电的一组充电曲线是如何形成的呢？

Yeah, it's a great question. And I should start by saying, you know, lots of companies out there who are innovating in this space. So I'll try and give you a broad outline of what I think is happening, but there's lots of things going on that are quite exciting. And I'm sure some companies are doing stuff that I don't know about. So I might not say what is cutting edge. If that makes sense. But okay, the first thing we should appreciate is that there are two sort of major sources of constraint, right? So one is how powerful is the power electronics that's connected to the car? So if you drive up to a supercharger or a non-Tesla kind of charger, you know, that is 50 to 100 to 150 to 200 kilowatts, there's going to be ultimately a power limitation in the electronics in that charger. It can only deliver a maximum power of some number. And that means even if the battery could take a lot of power, at least if you start from zero SSC where the battery is, that's the kind of happy place where the battery won't state lots of power on a warmish day. The first limit is going to be just the maximum power limit of the charger, right?

是的，这是一个很棒的问题。首先我要说的是，有很多公司在这个领域进行创新。所以我会尝试给你一个我认为正在发生的情况的大致概述，但是有很多令人兴奋的事情正在发生。我确信有一些公司正在做我不知道的事情。所以我可能不会说什么是最前沿的。如果这有意义的话。但是好吧，我们首先要认识到的是，有两个主要的限制因素，对吧？一个是与汽车连接的功率电子设备有多强大？所以如果你开到一个超级充电桩或一个非特斯拉型号的充电器，那可能是50到100到150到200千瓦，它们最终会受到充电器中的电子设备的功率限制。它只能提供某个最大功率。这意味着即使电池可以承受很多功率，至少如果你从电池处于零状态的位置开始，这是电池在一个温暖的天气中不会受到太多功率的理想位置。第一个限制将只是充电器的最大功率限制。

And then the second set of limitations come from the battery pack itself, okay? The other thing I should say, and I'm sure you and everyone listening would know this, but you know, there are sort of two types of charger. There's onboard charger and offboard charger. So if you're charging a car at seven kilowatts at home, that's actually using a power converter that's on the car. Whereas if you're charging it while driving across country, then the charger basically plugged directly into the DC bus and the electronics for doing AC to DC is outside the car. Yeah, I think we all know that. So then how do we determine the charging curve?

然后第二组限制来自电池包本身，好吗？另外一件我应该说的事情，我相信你和所有听众都知道，但你知道，充电器有两种类型。有车载充电器和离车充电器。所以如果你在家用七千瓦充电汽车，实际上是使用安装在车上的功率转换器。而如果你在全国行驶时充电，那么充电器基本上直接插入直流总线，负责从交流到直流的电子设备是在汽车外部的。是的，我想我们都知道这一点。那么我们如何确定充电曲线呢？

Well, we need to think about what limits the power in the battery, okay? And so there's limits come from different sources. One might be a thermal limit. We don't want to get the battery too hot. So if it's a super hot day, we're in a hot country and the battery is generating a lot of heat, maybe because its internal resistance is a bit higher, whatever, which could be for lots of reasons, then the charging power might need to be limited to avoid overheating. The cooling system in the battery, which would normally keep a cooler on a hot day while you're charging, is struggling.

好吧，我们需要考虑电池的功率受到哪些限制，好吗？这些限制可能来自不同的源头。其中一个可能是热限制。我们不希望电池过热。因此，如果是一个超级炎热的天气，我们处于一个炎热的国家，而电池正在产生大量的热量，可能是因为其内部电阻有点高之类的原因，情况可能出于很多原因，那么充电功率可能需要受到限制，以避免过热。电池中的冷却系统，在你充电时通常会在炎热的天气保持一个较凉爽，但此时可能正在发生困难。

But having said that, in general, warming the battery up helps with getting more power in, okay? And the opposite is true. If it's really cold, it's hard to charge. And I think we know this. I mean, if any of us have been skiing or snowboarding and it's been super cold, your phone battery might have died or whatever. So that's one first rule is thermal. So batteries are like it hot, but not too hot. If it's below 5 degrees centigrade, the internal resistance of battery goes up a lot and this starts to cause a limitation with respect to charging. And actually on this thermal point, there's been some interesting innovation done where people have proposed putting heating plates directly inside the cells and then kind of heating up the batteries to 50 plus degrees C in order to get fast charging to go better. Basically there's a trade off there because if the battery is then really hot and you've charged it really quickly, you then need to wait for it to cool down before you drive away. So you have to think a bit more globally. But anyway, so thermal is a limit.

但是，总的来说，预热电池有助于增加电池的充电量，对吧？反过来也是一样的。如果天气很冷，充电会比较困难。我认为我们都知道这一点。比如我们去滑雪或滑雪板时，天气很冷，手机电池可能会耗尽。所以第一个规则就是温度。电池喜欢温暖，但不要太热。如果温度低于5摄氏度，电池的内阻会大大增加，这会对充电造成限制。实际上，在这个热问题上，已经有一些有趣的创新，人们建议在电池内部直接安装加热板，将电池加热到50摄氏度以上，以便更好地进行快速充电。基本上存在一个权衡，因为如果电池非常热，并且你快速充电后，你就需要等待它冷却才能离开。所以你需要更加全面地考虑。总之，热问题是一种限制。

But the other limit is what we call lithium plating. Okay, so this is to do with driving the voltage on the anode, so on the negative electrode, the graphite with respect to, this is super technical, but with respect to a zero reference, which is defined by lithium electrode. Okay, I should say that for the science people in the room. Driving that voltage below zero results not in the intercalation reaction, which is the reaction we want, which is why we want to reversibly move lithium in an hour of the graphite, but instead it plates metallic lithium on the surface of graphite. And this is a problem.

但是另一个限制是我们所说的锂板层现象。好的，这与在阳极（即负电极）上驱动电压有关，即石墨相对于锂电极定义的零参考点。好的，我应该为在座的科学家们解释一下。将该电压驱动至零以下会导致不是我们想要的插层反应，即我们希望能将锂可逆地移动到石墨中，而是在石墨表面上形成金属锂。这是一个问题。

This is not what we want. So in lithium ion battery, normally lithium ion battery, so I'm not talking solid state or anode free or any of that stuff, just normal lithium ion battery. We never want the lithium to be in a metal form. We always want it to be in a compound, right? So it's either going to be intercalated into the graphite or it's going to be in the metal oxide on the other side. But yeah, so if we get the situation where we drive the voltage in such a way that it goes below zero volts with respect to lithium on the graphite, then we get lithium plating and that's bad because we can build up, well, we can build up little things that can puncture the separation inside the battery. And there's a whole host of other ways that that can go wrong. Okay, so we want to avoid pushing the current too high or the temperature too low in such a way that it would cause this to happen. So on a practical level, what this means is that as we get to higher states of charge where the voltage of the graphite electrode is lower, we have to be more careful. And as we get to higher currents, we have to be more careful. As we get to lower temperatures, we have to be more careful.

这不是我们想要的。所以在锂离子电池中，通常情况下，我说的是普通的锂离子电池，不是固态或者无阳极之类的。我们永远不希望锂以金属形式存在。我们总是希望它以化合物的形式存在，对吧？ 所以它要么会插入到石墨中，要么会在另一侧的金属氧化物中存在。但是，如果我们的电压以一种方式驱动，使得它相对于石墨降至零以下的情况出现，那么我们就会出现锂沉积，这是不好的，因为我们可能会堆积一些小东西，可能会刺穿电池内部的隔离层。这还有很多其他出错的方式。所以，我们要避免将电流推得太高或温度过低，以至于会导致这种情况发生。因此，在实际操作中，这意味着随着我们达到更高的充电状态，石墨电极的电压更低，我们必须更加小心。而且随着电流增大，我们也必须更加小心。当温度降低时，我们也必须更加小心。

So just to recap, so we can generally put lots of power into the battery if the temperature is ambient too high, but not too high. And if the current is, sorry, and if the state of charge is low, but if the temperature is low and the state of charge is high, we have to be a lot more careful about limiting the current. And you can solve this almost as an optimization problem, say like, what is the best path for the current to follow as I charge the battery up, as I follow an SSC?

所以简单来说，如果环境温度不太高，我们通常可以给电池充入大量电量，但不能太高。如果电流较低，抱歉，如果电荷状态较低，但是如果温度较低且电荷状态较高，我们必须更加谨慎地限制电流。你几乎可以把这个问题看作是一个优化问题，比如说，当我充电时电流应该如何最佳路径，当我遵循一个SSC时。

And that's kind of going to dictate the power curve. And what that optimization problem will say is charge with very, very high power for the first few minutes, and then gradually drop it down in order to avoid this lithium plating happening. Now, that very, very high power might then be limited by the power of the AC to DC converter. So yeah, so you can kind of think of there being a region where we're not really limited by the batteries for the first 20, 30% SSC from zero, was just limited by the power converter.

这将在一定程度上决定功率曲线。优化问题会建议在前几分钟内以非常高功率充电，然后逐渐降低以避免锂板聚现象发生。然而，这种非常高的功率可能会受到交流至直流转换器功率的限制。因此，可以想象在电池的前20-30%充电时，同时受到功率转换器的限制，而不是电池的限制。

And then after that, we start to ride along this constraint dictated by lithium plating. Does that make sense? It's kind of a drop to 80. That makes perfect sense to me, because just looking at a few of the variables here, graph height has a slightly different voltage than like pure lithium on the anode. If you push the charging too high, rather than jamming that into the graphite anode, which has a slightly higher voltage, then it starts plating pure lithium onto the anode. Is that correct? Yeah, yes. Yeah.

然后在那之后，我们开始沿着由锂板层规定的约束行驶。这样说有道理吗？这个过程中有一个下降到80的情况。这对我来说很明白，因为光看这里的一些变量，图形高度的电压与阳极上的纯锂有些不同。如果你把充电推得太高，而不是将其灌入电压稍高的石墨阳极中，它就会开始在阳极上镀覆纯锂。这是正确的吗？是的，是的。是的。

And you could say that there's a voltage where intercalation wants to happen, and there's a voltage where plating wants to happen. And when you get one or the other is dictated by what you do to the electrode in terms of voltage, it's not. All right. So there's, so we have those variables, the voltage and how hard you're pushing that to charge the battery.

你可以说，存在一种插层发生的电压，以及一种镀层发生的电压。当你达到其中一个电压时，取决于你对电极施加的电压，而非其他因素。所以我们有这些变量，电压和充电时对电池施加的力度。

And then you also have the temperature, which it's almost like a, it almost creates a speed limit or it's almost like the interest rate or something like that, where it's like it affects the fundamentals of the system, how it works. Yeah. Yeah. What's really going on there? The temperature is a slightly indirect effect because really the temperature limit is still a lithium plating voltage limit. But what's happening is because the battery's got internal voltage drops.

然后你还有温度，它几乎就像一个速度限制或者类似利率之类的东西，影响系统的基本运作。实际上，温度是一个稍显间接的影响，因为真正的限制是锂离子电池的电镀电压限制。但实际情况是，由于电池内部会有电压下降。

If you, so I'm an electrical engineer, so I think of it like the battery's like a voltage source and a resistor inside. And you can kind of think of that for each electrode for the graphite and for the NFC. Now, the resistor value is a function of temperature, and it's much higher resistance at low temperature and low resistance at high temperature. So what that does is it has the effective at low temperatures and high currents, causing a lot of internal voltage drop across the resistor, if I can put it like that, which drives the potential at the graphite surface in such a way that you get a little implating. Does that make sense? Yeah. Yeah. So this is, well, let's tie this together then.

如果你是一个电气工程师，那么我会把电池看作是一个电压源和一个内部电阻。你可以把这个想象成石墨和NFC每个电极的情况。现在，电阻的值是温度的函数，在低温下电阻值很高，在高温下电阻值很低。这样做在低温和高电流下会有有效果，导致在电阻器上产生很大的内部电压降，这会驱动石墨表面的电位，从而进行一些小的植入。明白了吗？是的。好的，让我们把这些联系起来。

So we have estimating the state of charge is one moving target and then estimating exactly when lithium plating is going to occur and at what temperature is another moving target. Is that correct? Those are, we have two moving targets there. Yeah. Okay. So how does a battery manufacturer determine when lithium plating is going to occur at one temperature? Do they just have to test hundreds and thousands of cells under different conditions to find exactly how those cells behave? Is that how they gather that data? Basically yes. Yeah. Lots of testing and quite a bit of increasing amounts of modeling. So yeah, basically get lots of cells from suppliers, test them at different voltages, currents, temperatures, and then often, or usually you do some destructive tear down analysis as well because you can kind of look at the surface and see whether there's been anything plating, expose it to lots of different diagnostic techniques and so on.

因此，我们估计电荷状态是一个移动目标，然后估计锂钝化何时发生以及在何种温度下发生又是另一个移动目标。这样理解正确吗？是的，我们确实有两个移动目标。好的。那么，电池制造商如何确定锂钝化将在某一温度下发生？他们是不是必须在不同条件下测试数百甚至数千个电池来发现这些电池的行为方式？他们是如何收集这些数据的呢？基本上是的。是的，很多测试，而且有相当多的建模。所以，基本上是从供应商那里得到大量电池，以不同的电压、电流、温度进行测试，通常或者说通常你还会进行了一些破坏性的拆解分析，因为你可以看一下表面看看有没有发生钝化，接着进行各种不同的诊断技术检测。

And then, you know, some iteration back to non-invasive measurements that you can do in the lab or on voltage and stuff like that as well. But yeah, there's no substitute for lots of test data unfortunately. All right. So what they do is they, my understanding is they gather all that test data and look at because each cell is actually slightly different because of manufacturing inconsistencies and inconsistencies and things like that. They take the best data they have, they form a table.

然后你知道，在实验室里或者进行电压测试等方面，可以回到无创测量的某些迭代过程。但是，很遈遗憾，没有大量的测试数据就没有替代品。所以他们所做的是，据我了解，他们收集所有测试数据并进行分析，因为每个电池实际上略有不同，由于制造不一致性和各种差异。他们利用最好的数据，制作表格。

So when your battery is deciding to, when you decide to charge your battery, my understanding is there's a lookup table you go, the battery management system goes, all right, under these conditions, this is what should be a safe charge curve or a safe charge that charge the vehicle. So is that correct? Yeah. I think so. Yeah. And you, I mean, you could probably solve an optimization problem in real time if I could put it like that. But assuming that the battery's condition is not changing rapidly, which it shouldn't be if it's a nice well-designed commercial stable long-lit battery, there's no point in my opinion doing that. You've just solved that problem beforehand and then store it in a lookup table like you've just described with some safety buffers and so on.

因此，当你的电池决定充电时，当你决定充电时，我的理解是有一个查找表，电池管理系统会根据这些条件确定安全的充电曲线或安全的充电方式来为车辆充电。这个理解对吗？是的，我认为是的。你可以实时解决一个优化问题，如果我这样说的话。但是假设电池的状态不会快速变化，如果它是一个设计良好的商业稳定的长寿电池，我认为没有必要这样做。你可以事先解决这个问题，然后将其存储在一个查找表中，就像你刚刚描述的那样，增加一些安全缓冲区等。

I think where there's still quite a bit of uncertainty and kind of interesting research to be done is around, well, okay, what happens after five, ten? 15 years. You know, we know that batteries age, they degrade, it might be a slow process. Generally, I think it's a slow, slow process. But that's going to shift the goalposts, right? It's going to shift the behavior of the electrodes.

我认为仍然存在很多不确定性和有趣的研究领域，即，在五年、十年、十五年之后会发生什么。我们知道电池会老化，会退化，可能是一个缓慢的过程。一般来说，我认为这是一个缓慢的过程。但是这将会改变目标，对极电极的行为产生影响。

And another thing that happens when I haven't mentioned at all, but it's really important is that all of this lithium plating and stuff is not homogeneous. So it's not uniform. There could be variations from particles to particles and across the cell and maybe from cell to cell within the pack. And so it's really important that manufacturers are able to get a handle on that non-uniformity issue. And again, modeling testing helps with that.

另外一个我还没有提到但非常重要的事情是，所有这些锂电沉积等情况并不是均质的。它们并不是一致的。在不同的颗粒、整个电池以及甚至来自电池组内的电池之间可能会存在变化。因此，制造商能够掌握这种非均匀性问题非常重要。再次强调，建模测试有助于解决这个问题。

But there's things like the position of the tabs in a pouch cell will have an impact on where the current is going and therefore some parts of the battery might warm up more and some will warm up less and the SSC will be slightly different in some regions compared to other regions and so on. So it's a really complex kind of spatially distributed problem within a cell. That makes sense.

但是，例如袋式电池中的铜片位置将影响电流的流向，因此电池的某些部分可能会变热，而其他部分可能会变冷，SSC在某些区域与其他区域相比会略有不同，等等。因此，它实际上是一个细胞内部复杂的空间分布问题。这是有道理的。

And so the lookup table that you've described is going to be your sort of best guess at the average with some safety buffer. All right. And we'll look a little bit more at the hardware side of things in a second. Before we look at that, is the discharge rate, I know the charge rate is determined by these curves, is the discharge rate also governed by these things?

因此，您描述的查找表将是您对平均值的最佳猜测，并带有一定的安全缓冲区。好的。接下来我们将稍微更多地看一下硬件方面的事情。在我们查看硬件之前，放电速率，我知道充电速率是由这些曲线确定的，放电速率也受这些因素所控制吗？

Right. So discharge, you're not worried about lithium plating. That only happens when you're charging. So that's good. So with discharge, we're more worried about things like thermal management, where the batteries can overheat, which to be honest, it's only an application where say you need to discharge our battery in five minutes is that a problem.

没错。关于放电，你不需要担心锂钝化的问题。那只会发生在充电过程中。所以这是好事。在放电过程中，我们更担心的是热管理等问题，电池可能会过热。老实说，只有在需要在5分钟内放空我们的电池的应用中才会出现问题。

So maybe if you've got an un-introductable power supply specifically designed to do a five minute discharge from 100 to zero, then you might worry about overheating. But I think generally speaking, and someone will probably write in and say I'm wrong, fair enough. But generally speaking, we're not so worried about the discharges, we are about the charge.

也许如果你有一个特别设计用于从100到零进行五分钟放电的不可介绍的电源，那么你可能会担心过热问题。但我认为一般来说，可能会有人写信来说我错了，说得对。但一般来说，我们不太担心放电问题，我们更担心充电问题。

I mean, another way of thinking about it is when you're charging the battery, you're kind of pushing everything in the direction it doesn't want to go. And so it's a bit more fragile and dangerous. But when you're discharging the battery, it wants to discharge. So it's a bit more well-behaved. That's a really hand-wavy explanation. But I hope you can make sense. That makes sense.

我的意思是，另一种思考的方式是，当你充电电池时，实际上是在把一切推向它不愿意去的方向。因此，它会变得更脆弱和危险一些。但是当你放电电池时，它想要放电。所以它会表现得更加听话。这只是一个比较模糊的解释，但我希望你能理解。这是有道理的。

So let's tie this together with a few other different variables. When you're designing a battery cell, you take into account what type of characteristics you want out of that battery cell. And those include things like cost, cycle life, and energy density. There's this balance of things that you have to take into account. Does that also happen on the software side? For instance, could you discharge a battery, or could you set up the charging curve or the lookup tables for a battery in such a way that the battery would charge twice as fast? You would get about half the life out of it.

让我们将这个与其他几个不同的变量联系在一起。当你设计一个电池单元时，你会考虑你想从这个电池单元中获得的特性。这些特性包括成本、循环寿命和能量密度等等。你必须在这些因素之间取得平衡。在软件方面也会发生这种情况吗？例如，您能否放电电池，或者能否设置电池的充电曲线或查找表，以使电池充电速度加快一倍？这样做会减少电池的寿命一半。

Right. Yeah, I see what you're saying. I mean, first of all, yeah, I completely agree that there's a kind of a trade-off between how hard you're pushing the battery, how long it lasts, and cost. And there's kind of good reasons for that. We don't have time to go into detail. There's some nice articles on the internet. But yeah, absolutely, you're right. So I think we see a good example of where this maybe plays out, if I can say, is in grid storage systems.

是的。是的，我明白你的意思。我的意思是，首先，是的，我完全同意在推动电池使用强度、持续时间和成本之间存在一种权衡。而且这背后有一些很好的理由。我们没有时间详细讨论。在互联网上有一些不错的文章。但是，是的，你说得对。所以我认为我们可以看到一个很好的例子，也许可以说，在电网储能系统中会发生这种情况。

So we'll come back to electric cars in a minute. But in grid storage systems, I'm so this is stationary batteries basically plugged into the power grid. So I'm buying a large battery. In fact, we have one down the road from here. Well, a few miles down the road in Oxford, here where I'm based, which is 50 megawatts, so it's big. It's like a field full of containers full of batteries plugged into the transmission grid.

所以我们马上会回到电动汽车。但是在电网储能系统中，这就是静态电池基本上都是插入到电网中的。我们正在购买一个大型电池。事实上，在这里附近的几英里外的牛津，就有一个50兆瓦的大型电池。它非常大，就像是一个满是插入到传输电网中的电池的集装箱场。

And what that battery does is it provides services to support the power grid. And those services range from just charging, discharging when the energy is cheap or expensive to make money or supporting the frequency response on the grid and so on. And if I'm an investor building one of these big batteries, you know, this is a tens of millions of dollars, tens of millions of pounds project, I need to know what's the return on my investment. And that's going to end a lot on two things.

而电池的功能是为支撑电网提供服务。这些服务包括从在能源便宜或昂贵时充电、放电以赚钱，到支持电网上的频率响应等等。如果我是一个投资者，正在建造这样一个大电池，这是一个价值数千万美元、数千万英镑的项目，我需要知道我的投资回报率是多少。这将取决于两件事情。

The revenue that the battery makes and the lifetime. And so this trade off that you've just described, absolutely critical for that kind of application. And I have this difficult choice. Do I sweat the asset? Do I push the battery quite hard? Maybe cycl it three times a day or something, but degraded more quickly and then have to, you know, miss out on future revenue. I can put it like that. Or do I do it quite slowly? It lasts a long time, but I miss out on present revenue. And I think there's a sweet spot in the middle. There's a kind of octopus between those two extremes. We've done some work on this recently. So if anyone's interested, I can send you a paper. But I think this plays out to a similar extent with electric cars, although it's a little bit different with electric cars because you're not charging and discharging to make money per per say. You might want to control the charging so that you get this sweet spot correct. So you don't fast charge like four times a day. That would be a bad idea.

电池产生的收入和寿命。所以你刚才描述的这种权衡，在这种应用中绝对至关重要。我面临着这个棘手的选择。我要保护资产吗？我要把电池用得很厉害吗？也许一天循环使用三次或者类似的方式，但这样会加速电池老化，然后必须要，你知道，错失未来的收入。我可以这样说。还是我要慢慢使用？它可以持续很长时间，但我会错过现在的收入。我认为中间有一个黄金点。在这两个极端之间有一种扩散效应。我们最近做了一些相关工作。如果有人感兴趣，我可以给你发送一篇论文。但我认为这种情况在电动汽车中也会同样发生，尽管电动汽车有点不同，因为你不是为了赚钱而进行充放电。你可能想要控制充电，以便让这个黄金点正确。所以你不要快速充电四次一天。那是一个坏主意。

But most people I think are not doing that. But the discharge is not really, you don't have control. That just depends on driving. And so the battery just has to do what the driver needs it to do. Where I think it gets interesting is where we start to think about things like vehicle to grid because then your electric car is becoming much more likely grid battery and providing these kind of bidirectional services to the grid. The other thing just to finish the point is different chemistries may be slightly different in this regard. And also different variations of the same battery.

但我认为大多数人并没有这样做。但是电池的放电并不真的是可以控制的。这取决于驾驶。因此，电池必须执行驾驶员需要的任务。我认为有趣的地方是当我们开始考虑诸如车辆对电网之类的事情时，因为这样你的电动汽车就会变得更有可能成为电网电池，并向电网提供这种双向服务。另一个要点是，不同的化学成分在这方面可能略有不同。同一种电池的不同型号也可能存在差异。

So I can actually optimize a battery for power or for energy. For example, I can have thin electrodes or thick electrodes. I can change the thermal management system. And it might cost me money to do that. Of course, more cooling, more expense, but maybe I can do more cycling without degradation. So when we talk about this three way trade off that you mentioned, we should definitely think about the system level as well. And how much do I want to throw out my HVAC system to keep a battery in the sweet spot firmly? Yeah. So you say, for instance, you might have the same battery and you could use it for grid storage or an EV and you might tweak the charge curve depending on which one of those use cases and what your priority is.

因此，我实际上可以优化电池的功率或能量。例如，我可以有薄电极或厚电极。我可以改变热管理系统。做这些可能会花费我一些钱。当然，更多的冷却，更高的费用，但也许我可以做更多的循环而不会降解电池。因此，当我们谈到您提到的这种三方面权衡时，我们一定要考虑系统级别，以及我愿意为保持电池在最佳状态而抛弃多少空调系统。是的。例如，您可能有相同的电池，您可以将其用于电网储能或电动汽车，并根据使用情况调整充电曲线，根据您的优先级。

If you want that battery to last a lot longer, you might slightly change the charge curve as opposed to the way you'd manage that charge curve in the vehicle. Yeah, 100% definitely. And a really good example of that is I think if you were using your vehicle for vehicle to grid, you would limit the SSC window. So you'd probably bounce around 50%. I mean, it depends a little bit on the exact chemistry, but we know that if you hold a battery out, extremes of voltage, typically at high voltage, that's bad from a lifetime point of view. And so, for instance, I think vehicle to grid is actually a really good idea. I mean, I have an electric car. I also have a grid battery at my house because I'm a battery guy.

如果你希望电池的使用寿命更长一些，你可能需要略微调整充电曲线，与你在车辆中管理充电曲线的方式有所不同。是的，绝对是这样。一个很好的例子是，我认为如果你将车辆用于车辆对电网，你会限制SSC窗口。所以你可能会在50%左右摆动。这取决于确切的化学成分，但我们知道如果让电池处于极端的电压，特别是高电压，从寿命的角度来看是不好的。所以例如，我认为车辆对电网实际上是一个非常好的主意。我的汽车是电动汽车。我家里也有一个电网电池，因为我是个电池人。

My home battery, it's much smaller than capacity compared to my electric car battery. It doesn't make sense, especially at the moment. I mean, we're in springtime here in the UK. I have solar panels on my house. Amazingly, we're still covering most of our energy from solar, even in the UK, right, where there's not always that great. And so we just need a few kilowatt hours here and there for the next six months to store our home energy. I mean, we're essentially off grid, right, which is pretty exciting. And it's sort of silly that I've got two batteries, one in my car and one in my house. I should just be using the mid 10, 15, 20% range of my car battery when it's plugged in and out.

我的家用电池，与我电动汽车电池相比要小得多。这在这个时刻并没有什么意义，尤其是在英国的春天。我的房子上安装了太阳能电池板。令人惊讶的是，即使在英国，我们仍然可以用太阳能覆盖大部分能量，对吧？这并不总是那么好。因此，在接下来的六个月里，我们只需要储存一点点千瓦时的家庭能量。我是说，我们基本上离网了，这真的很令人兴奋。而且我在车上和家里各有一个电池，有点傻。当我插上车时，我应该只使用我的车电池的中间 10、15、20% 范围。

Yeah, I know there's a lot of people looking forward to using the battery packs in the vehicle as well. Fully utilize it as an asset. Yeah. But in order to do that in such a way that you don't degrade it, you have to very carefully manage the SSC range and keep it quite limited. You can't just swing from zero to 100 and back to zero. I think that's probably a bad idea. Yeah. So moving along, Elon has said that LFP batteries want to be charged to 100%. But my understanding is that LFP batteries at it's a bit more complicated than that. And at 100% state of charge, just like other batteries, LFP batteries do degrade more quickly. They don't degrade as rapidly as say like a nickel battery minded 100%, but they still degrade more rapidly at 100% than like say 70%.

是的，我知道有很多人都期待着将电池组用在车辆中。充分利用它作为一种资产。但为了在不降低电池寿命的情况下这样做，你必须非常小心地管理充电范围，并保持它相当有限。你不能从零突然充满，然后再从满电变成空电。我认为那可能是个坏主意。所以继续下去，埃隆说LFP电池希望被充电到100%。但我理解LFP电池比这更复杂一些。就像其他电池一样，在充满电的状态下，LFP电池会更快地退化。它们的退化速度不像镍电池一样迅速，但在100%的状态下它们仍然比70%时更快地退化。

So from a cycle life perspective, you don't want to be charging to 100% all the time. However, it seems to be there's a tug of war because in order to accurately measure the state of charge of the battery, and for those battery cells to balance within the, to top them all up and for the system to get an accurate state of charge, you have to bring that battery pack up to 100% occasionally. Yeah. So my question is, where is the happy like because of that tug of war, where's like how often should people charge their battery to 100%? And if they don't charge their battery to 100% will that cause degradation by the cells getting out of balance? Does that make sense? Yeah, it does. So I think you're saying you need to go to 100% for SOC calibration based on all with everything we discussed earlier, hysteresis, flat voltage curves, but you don't want to go to, you don't want to stay at 100% all the time.

从循环寿命的角度来看，您不希望一直充电到100％。然而，似乎存在一种拉锯战，因为为了准确测量电池的充电状态，并让这些电池单元在之间平衡，充电到100％是必要的，以便系统能够得到准确的充电状态。所以我的问题是，在这种拉锯战中，到底应该如何找到平衡点，人们应该多久充电到100％呢？如果他们不充电到100％会导致电池单元失衡而造成降解吗？这样理解对吗？是的，我认为您是在说，根据我们之前讨论的所有内容，需要充到100％进行SOC校准，但不要一直停留在100％。

Yeah, because it will degrade the battery more quickly because there's a certain side reaction called solar electrolyte interface, which forms on the graphite. And this is accelerated at high voltage or high SOC. Yeah. And unfortunately, I don't have the numbers in front of me at the moment. I should have. So one question is how much more is this side reaction accelerated at 100% compared to 50% or 30% for LFE? And I guess I would say it is accelerated, but it's probably not as scary as we might think, especially when you bear in mind that most commercial battery applications have a buffer at the top anyway.

是的，因为这样会更快地降低电池的性能，因为会产生一种叫做太阳能电解质界面的副反应，在石墨上形成。这种情况在高电压或高SOC下会加速发生。不过很遗憾，我现在手头没有具体数字。我应该有。所以一个问题就是在LFE的情况下，100%相比于50％或30％这种副反应会加速多少？我想这种副反应确实会加快，但可能没有我们想象的那么可怕，特别是当你考虑到大多数商业电池应用本身在顶部就有一个缓冲区时。

So you know, although you want to get beyond the flat voltage curve onto the sort of bit near the top. You would still leave a few percent up there. And so when the system says this is 100%, this is the case with my own battery. It's actually a 95%. And so this degradation issue, it's there. And if we could avoid it, that'd be great. But it's probably not worth worrying about too much because in general LFE is pretty good from a lifetime point of view. I think if we were holding the battery at true 100% at high temperature for days and days and days and days and days, that would be a problem.

所以你知道，尽管你想要超越平坦的电压曲线进入接近顶部的范围。你仍然会留下一些百分比在那里。所以当系统显示这是100%时，对于我的电池情况来说实际上是95%。所以这种衰减问题是存在的。如果我们能够避免这种情况，那将是很好的。但可能不值得太过担心，因为总的来说，从寿命的角度来看，锂电池是相当不错的。我认为如果我们将电池在高温下真正保持在100%很多天，这将是一个问题。

But that's the kind of magnitude of where we need to go to make it a problem. That makes sense. That makes sense. So you just don't want to keep your battery plugged in at 100% and for instance high temperatures because over time, that would accumulate and would create more degradation. Yeah. So going, I keep talking about home batteries. It is a problem with, it could be a problem with home batteries. So right now, my home battery is bouncing between 100% and 60% every day because there isn't any option in the software.

但这是我们需要解决的问题的重要性等级。这是有道理的。这是有道理的。所以你不想让电池长时间保持在100%和在高温环境下，因为这样会随着时间的推移积累并导致更多的降解。是的。所以我一直在谈论家用电池。这可能是家用电池的一个问题。所以现在，我的家用电池每天在100%和60%之间波动，因为软件中没有任何选项。

It's not a Tesla system, I should say that. It's another one. But there isn't any option in the software for me to adjust the maximum SOC limit. And because we have a lot more solar than we need most days at the moment, which is amazing, the battery is just bouncing between 160% or whatever instead of what would be much better, 30% and 70%. And so, yeah, that's kind of nice in the sense that a simple software fix could actually extend the life slightly. So I'm trying to persuade the manufacturer to think about that. But of course, then what you said earlier might kick in that the SSC calibration goes out the window. And how much of a concern is that? Well, that is an interesting question.

这不是特斯拉系统，我应该说这是另一个系统。但软件中没有选项让我调整最大SOC限制。因为我们现在的太阳能比我们需要的要多很多，这真是太棒了，电池的SOC限制就一直在160%左右而不是更好的30%和70%。所以，这其实挺好的，一个简单的软件修复就能稍微延长电池的寿命。我正试图说服制造商考虑这个问题。但当然，你之前所说的SSC校准可能会失效。这是一个值得考虑的问题。

And it depends a little bit on other choices that the manufacturer has made. How good is their current sensor, how accurate is their modeling and so on and so forth. I imagine that it could be the kind of thing where you could have a backstop. So you could say, look, yeah, fine, I'll let you have a maximum SOC of 60%. But then every week it goes back to 100 for one day or whatever, just to calibrate. So again, I think it's a sort of solvable problem. Yeah. So there's two issues there when the batteries go out of calibration. One or out of balance, that is where the battery management system can't read the state of charge as well anymore, because they haven't been topped up to 100%. One of those issues is, well, you can't get as much utility out of your battery because you don't know if you're actually at the accurate state of charge.

这取决于制造商做出的其他选择。他们目前的传感器有多好，他们的建模有多准确等等。我想这可能是一种情况，你可以设定一个安全限制。所以你可以说，好吧，我让你最多充电到60%。但是每周会有一天或者其他时间回到100%，只是为了校准。所以我认为这是一种可以解决的问题。是的。 所以当电池失去校准时有两个问题。一个是失去平衡，也就是电池管理系统不能读取电池的充电状态了，因为它们没有再次充满到100%。其中一个问题是，你无法充分利用你的电池，因为你不知道你的电池实际上处于准确的充电状态。

So 95% might be actually 100% state of charge or vice versa. You don't really know what 0% or 100% is anymore accurate. So you might lose some utility out of the battery cell. But my understanding is when those cells go out of balance, it starts creating a bit of strain on some of the battery cells because each of the battery cells isn't experiencing identical conditions anymore. Are those two variables correct? Yeah, I think we're talking about a few different things. So maybe just to clarify, so there's one issue related to the fact that the Coulomb counting that I mentioned at the beginning can just drift. So we can, and that would be the case, even if I had a single cell. So a single cell, if I've got some noise and some offsets in my current sensor, even if I'm just not sampling often enough, then the accumulation of SSC is going to gradually drift away from where it should be. And so one reason we need to reset is that reason. That is unrelated to having lots of cells connected together. That's just to do with the fact that I'm adding something up in accumulating error. The second issue that you've mentioned relates to what happens if I have lots of cells. Do they all behave the same? What happens when they start behaving differently? And the answer to that is it depends a little bit how they're connected. If they're connected in parallel, then they tend to self-balance a little bit. So if one of them gets to a higher voltage, then another one, some current will flow into the one with a lower voltage and they'll kind of regulate in that way. Again, that becomes a little bit more tricky when you've got flat voltages and hysteresis, just as a side point. But if I've got cells connected in series, then they all have the same current flowing through them. And so if one of them reaches the maximum or minimum voltage, sooner than the other ones, because we always measure all the voltages on every cell in series, from a safety point of view, we have to do that. I will then stop charging because I don't want to overcharge that one cell. It's got to maximum voltage. And then the balancing system would kick in and maybe bypass that cell and charge up all the other ones, which is typically a slow process because we can't put much current through the bypass circuit. That makes sense. But yeah, so I think in the case of the first situation where we have Coulomb-County-mitch drips, that's kind of a problem. We don't necessarily know where we are and we actually lost. In the case of the second situation, assuming one cell in the string reaches a voltage limit, we do know where we are and then we can make some decisions. Does that help? Yeah, what I was trying to put my finger on is whether it causes damage to the battery pack and then the cells are out of balance. In principle, it doesn't, although it depends. But in the simple example where I've got lots of cells in series, as long as I'm measuring the voltage of every cell and I don't overcharge or undervoltage any of those cells, it's not going to damage anything. I just might have less capacity than I think. That makes sense.

所以有可能95%实际上可能是100%的充电状态，反之亦然。你真的不知道0%或100%到底是多准确。所以你可能会因为电池单元失去一些效用。但我理解的是，当这些电池单元失去平衡时，会对其中一些电池单元造成一些压力，因为每个电池单元正在经历不同的条件。这两个变量是正确的吗？是的，我想我们谈到了一些不同的东西。 也许我可以澄清一下，起初提到的库仑计数可能会受到漂移的影响。即使只有一个单元的情况下也会发生这种情况。所以，如果我的电流传感器存在一些噪声和偏移，甚至我采样的频率不够高，那么累积的具体容量会逐渐偏离应该的数值。重置的原因之一就是因为这个原因。这与连接在一起的多个单元无关。这只是因为我在累积错误。 你提到的第二个问题与拥有多个单元的情况有关。它们是否都表现相同？当它们开始表现不同的时候会发生什么？答案取决于它们的连接方式。如果它们是并联连接的，那么它们会自我平衡一点。所以如果其中一个电池达到了更高的电压，电流就会流向电压较低的电池，它们会以这种方式调节。当电压平坦且存在迟滞时，这就会变得有点棘手。 但如果我的电池单元是串联连接的，那么它们都会有相同的电流流过。所以如果其中一个电池单元比其他的更早达到了最大或最小电压，因为我们总是测量串联电池中每个电池的电压，出于安全考虑，我们必须这样做。那么我会停止充电，因为我不想过度充电那一个电池。然后平衡系统会启动，也许会绕过该电池并为所有其他电池充电，这通常是一个缓慢的过程，因为我们无法通过旁路电路引入太多电流。这听起来有道理。但是，在第一个情况下，当库仑计数发生漂移时，这可能是一个问题。我们可能不知道我们在哪里，事实上我们已经迷失了。在第二种情况下，假设串联中的一个单元达到了电压极限，我们知道我们在哪里，然后我们可以做出一些决定。这有帮助吗？ 是的，我试图确认的是，它是否会对电池组造成损坏，然后电池单元失去平衡。原则上，它不会造成损坏，尽管这要取决于具体情况。但在一个简单的例子中，如我有很多串联的电池单元，只要我测量每个电池单元的电压，不会对这些电池单元中的任何一个进行过充电或欠电压，就不会造成任何损坏。我可能只会比我想像中的容量少。这有意义。

And there's companies who, including a spin-out company from our research group, which are working on electronics to kind of get around this problem by giving you more degrees of control, more extreme balancing. That helps a lot because I have asked probably 20 people this question and I've never really gotten a clear answer. The answer is of course nuanced, but what I'll do is I'll take what I've learned from this video and I'll make kind of an explainer video on it because I don't know if everybody will be following exactly along with what we're talking about. We're getting into the weeds of it, which I really enjoy.

还有一些公司，包括我们研究小组的一个分立公司，正在研究电子技术，以解决这个问题，通过提供更多程度的控制和更极端的平衡。这对我很有帮助，因为我询问了大约20个人这个问题，但从来没有得到一个清晰的答案。答案当然是微妙的，但我会根据这个视频中学到的知识制作一个解释视频，因为我不确定是否每个人都会完全理解我们正在谈论的内容。我们正在深入探讨这个问题，我真的很喜欢。

Yeah, no problem. And happy to give you a bit more info on that specific issue. Okay, so there's three questions left that we have. Sometimes people will see a rapid change in the state of charge of their battery cell. How does that occur? Is your battery, for instance, when it's using those lookup tables, does it use an average of information over the past five minutes or is it constantly in a real-time basis adjusting where it's looking on the lookup tables? Right, so I think I've seen something like what you described on an old laptop, for example, where, I mean, four years later, the SSC would kind of go down and down and then it gets like 15% and then it would just stop working sometimes. Is that kind of what you mean?

没问题。很乐意为您提供关于这个特定问题更多的信息。好的，我们还有三个问题。有时候人们会看到电池电量迅速变化。这是怎么发生的呢？比如，您的电池在使用这些查找表时，是使用过去五分钟的信息平均值，还是不断地实时调整查找表的位置？嗯，我想我在旧笔记本电脑上看到过您描述的情况，比如四年后，电池电量会逐渐下降，最后只有15%，有时候会出现停机现象。您是不是指的是这种情况？

Yeah, that would be one of the instances, but I know some people who have parked their car sometimes and they come back to the car and there's an unexpectedly large change in the state of charge. Okay, so I think there's two different, potentially two different issues here. So the one issue which relates maybe to what you're talking about is actually not to do the lookup tables or anything with the BMS. It's just whether the car is using energy while it's parked and some cars use more than others. You know, if a car is running kind of power-hungry compute equipment, doing security stuff or whatever, that can actually suck more than you expect over a few hours. So that, if you're like, that's a sort of legit reason for the SSC to change. It's just actual use of energy.

是的，这可能是其中一个情况，但我认识一些人有时停车，回来时发现车辆的充电状态发生了意外地大的变化。好的，我认为这里可能存在两种不同的问题。一种可能与你所谈论的相关，实际上与查找表或电池管理系统无关。只是车辆停放时是否在消耗能量，有些车辆消耗的能量比其他车辆多。如果车辆运行着耗电量大的计算设备，执行安全任务等，这实际上会消耗比你预计的更多的能量。因此，如果车辆消耗了能量，这就是SSC改变的一个合理原因。

But if it's changed and the car or the laptop or whatever hasn't really been using much current, then yeah, maybe what's happened is the lookup table has become invalid. So you do your test on your battery at the beginning of life. You say, I've got the voltage versus SSC curve. I know my model parameters brilliantly. Everything's amazing. Sensors are well calibrated, whatever. And then five, six, seven, eight years later, the battery's aged a bit. The cells have maybe damaged a bit. That lookup table, those values, not so good anymore. And so that would exactly cause what you've described. You know, the lookup table is saying one thing, reality is something, saying something else, the voltage measurement, saying something, and you suddenly cut off on the basis of a voltage measurement just dropping sooner than you expect.

但是如果发生了变化，汽车或者笔记本电脑或者其他设备并没有在使用大量电流，那么也许发生的情况是查找表已经变得无效了。因此在电池寿命开始阶段进行测试。你会说，我有电压与SSC曲线。我完全了解我的模型参数。一切都很完美。传感器校准良好，等等。然后五、六、七、八年后，电池老化了一些。电池单元可能已经受损。那个查找表中的数值不再那么好了。这就会导致你所描述的情况。查找表在显示一种情况，实际情况又不同，电压测量结果显示另外一种情况，最终你会根据电压测量结果突然断电。

Perfect. So now moving on to the second of the three questions. Are there any upcoming advancements in AI, battery modeling, or electronics that could make batteries last longer or fast charger? I've seen some people saying that, hey, we don't need to make any changes to the battery cells. We can extend the life considerably, or we can make them charge a lot faster simply by using a different or better system of monitoring them. Right. Yeah. So it's a good question. I mean, I think there's a lot of hype around this. So we have to be a little bit careful to kind of say that. Machine learning is exciting, but it's also, you know, everyone's on the bandwagon. It's very exciting.

太好了。那么现在我们来讨论三个问题中的第二个。在人工智能、电池建模或电子领域是否有即将到来的进步，可以让电池更持久或实现快速充电？我看到一些人说，嘿，我们不需要对电池进行任何改变。我们可以通过使用不同或更好的监控系统大大延长其寿命，或者让它们充电速度更快。是的。这是一个很好的问题。我认为围绕这个问题存在很多炒作。因此，我们必须小心翼翼地说。机器学习很令人兴奋，但同时也要意识到，每个人都在跟风，这也是非常令人兴奋的。

So I guess one thing I would say is it depends a little bit on what your baseline is, right? So we could say, yeah, things are super exciting. We can make loads of improvements, especially if you have a badly built, badly designed, badly calibrated battery. But I would say in that case, well, you should probably just use the conventional techniques better, right? Get a proper current sensor, prioritize your circuit models, whatever. So I think on the other hand, AI is quite interesting. There's a few areas where I can see benefits. Lots of people are working on materials discovery. So for just for new battery materials, searching like massive such bases looking for new types of materials, that's one aspect.

所以我想说的一点是，这取决于你的基准是什么，对吧？我们可以说，是的，事情非常令人兴奋。我们可以进行大量改进，特别是如果你有一个糟糕建造、设计不良、校准不良的电池。但在这种情况下，我会说，你应该更好地使用传统技术，对吧？获取一个合适的电流传感器，优先考虑你的电路模型，等等。所以我认为，另一方面，人工智能是非常有趣的。有一些领域我可以看到好处。许多人正在研究材料的发现。所以只针对新型电池材料，搜索大量的数据库寻找新类型的材料，这是其中的一个方面。

I think you can use kind of AI type techniques to help speed up optimizations. So if you're doing design or something, you can use AI for that. If you have a lot of data, so if you're a battery manufacturer, building a gig factory or, you know, some kind of production system, then you could use machine learning techniques to look at anomalies in your data. You could improve your manufacturing processes. You could look at where the bottlenecks are and so on and so forth. I think with respect to all of this, a lot of those techniques are quite well established. The issue is actually more whether we have rich enough data. And it's particularly hard with lifetime modeling because we want to know how the battery is going to perform over five, six, seven, eight, nine, 10 years. But the battery technology in the chemistry keeps advancing all the time. So it's like a chicken and egg kind of situation, which makes it really tough. But yeah, if you were a manufacturer with lots and lots of data, I think you're in quite an exciting position to use AI to look for potential improvements. But I don't want to oversell those improvements. I mean, they might be five, 10%, maybe even 20% if you're lucky, but they're not going to be 200% in my opinion.

我认为你可以使用一些人工智能技术来帮助加快优化速度。所以如果你在做设计或其他事情，你可以使用人工智能来帮助。如果你有大量数据，比如如果你是一个电池制造商，建造了一个大型工厂或者某种生产系统，那么你可以使用机器学习技术来查看数据中的异常。你可以改善你的制造流程，查找瓶颈所在等等。我认为在这方面，很多技术都已经相当成熟。问题实际上更多的是我们是否有足够丰富的数据。尤其对于寿命模型来说，情况就更加困难了，因为我们想知道电池在五六七八九十年内会表现如何，但是电池技术和化学成分一直在不断进步。所以这就像是一个先有鸡还是先有蛋的情况，使得情况变得很艰难。但是，如果你是一个拥有大量数据的制造商，我认为你处于一个相当令人兴奋的位置，可以利用人工智能寻找潜在的改进。但我不想过分吹嘘这些改进。我意思是，这些改进可能会有5%、10%甚至20%，如果你很幸运的话，但在我看来不会达到200%。

Yes, you discover a new battery material, a new battery configuration, which is like double the energy density. Yeah, like any other innovation in the battery space, you have to take a closer look at what they're doing and look at the market and go, all right, what's for instance, what's your benchmark? Because if you're using a terrible benchmark, of course, you're going to look better. Yeah, it's really easy to make things look great if you use a bad starting point. Yeah. So last question, is there anything you're working on that you'd like people to know about or what's the best way to follow you?

是的，你发现了一种新的电池材料，一种新的电池配置，能量密度翻倍。是的，就像电池领域的任何其他创新一样，你必须仔细看看他们在做什么，看看市场并且思考，好的，例如，你的基准是什么？因为如果你使用糟糕的基准，当然，你会看起来更好。是的，如果你使用糟糕的起点，就很容易让事情看起来很棒。最后一个问题，有什么你正在从事的事情想让人们知道吗，或者最好的方式是如何关注你？

Oh, that's super kind. So I do have a Twitter account. I'm not on there very much these days. I'm trying to do more in real life. I'm on LinkedIn as well. So people can look me up there. We have research group website, which I must update. The kinds of things that we are working on, which I'm excited about, we've actually done a lot of work on grid storage. So it kind of moved away from electric vehicles a little bit. One of the reasons for that is because you have more control over the battery. So if you're a control engineer, you want to control batteries. Grid storage is great. And also, I think we're seeing rapid transition certainly in the UK, for example, over here in the power grid, lots of solar, lots of wind, which is great. But grid storage is kind of an unexplored territory in terms of the way of the markets and the machine learning and battery physics kind of coming together and evolving.

哦，太好了。我确实有一个Twitter账号，但最近并没有经常使用。我正在努力更多地融入现实生活中。我也在LinkedIn上。人们可以在那里找到我。我们有研究小组的网站，我必须更新一下。我们正在努力研究的内容让我感到兴奋，我们实际上在电网储能方面做了很多工作。因此有点偏离了电动汽车的方向。其中一个原因是因为你对电池能够有更多的控制权。因此，如果你是一个控制工程师，你会想要控制电池。电网储能非常重要。此外，我认为我们正在看到很快的转变，特别是在英国，例如这里的电网上，有很多太阳能和风能，这是很棒的。但是，电网储能在市场、机器学习和电池物理学方面是一片尚未开发的领域，它们可以相互结合演进。

So doing quite a bit of work on that. We're also doing work on machine learning from lifetime prediction. We're doing work on equivalent circuit models. We're doing work on physics based models. So if you're interested in battery modeling in general, ranging from devices up to systems, then that's kind of where we're at. And I'm happy to tell you more. And sorry, what was the name of that team or that group or that you're working with on all this?

所以我们在这方面做了很多工作。我们还在做寿命预测的机器学习工作。我们在做等效电路模型的工作。我们在做基于物理的模型工作。所以如果你对电池建模感兴趣，无论是从设备到系统，这是我们目前所在的领域。我很乐意告诉你更多。对不起，那个团队或组织的名称是什么，你是和他们一起做所有这些工作的？

Yes. So the research group that I run here at Oxford is called Battery Intelligence Lab. I'll send a website later on. I appreciate your time. This has been very enlightening for me. As I said, a lot of these questions I've been trying to get better answers to for several years now. And now I finally feel like I have a better understanding of how these battery charging curves work and what their role is. And I'll use that and I'll package it up into a really tight video package at some point. So thanks for your time. I appreciate it.

是的。我在牛津大学主持的研究小组叫做电池智能实验室。稍后我会发送一个网站。感谢您的时间。这对我来说非常启发。正如我所说，这些问题我已经尝试多年，希望能得到更好的答案。现在我终于感觉我对电池充电曲线的工作方式和作用有了更好的理解。我会利用这些知识，制作一个非常严谨的视频。感谢您的时间，我非常感激。

Amazing. Thanks for having me. And hopefully some of what I said is actually correct. But I'm sure people can write in and tell us, and I'd love to hear from you if you disagree. Good. Good. Have a great weekend. Bye. Bye. If you enjoyed this video, please consider supporting the channel by using the links in the description. Also consider following me on X. I often use X as a testbed for sharing ideas and X subscribers like my Patreon supporters generally get access to my videos a week early. In that note, a special thanks to my YouTube members, X subscribers, and all the other patrons listed in the credits. I appreciate all of your support, and thanks for tuning in.

太棒了。谢谢你邀请我来。希望我说的一些是正确的。但我相信大家可以写信告诉我们，如果你有不同意见，我很乐意听取。好的，好的。祝你周末愉快。再见。再见。如果你喜欢这个视频，请考虑通过描述中的链接支持本频道。也请考虑关注我在X上的账号。我经常在X上分享想法，X订阅者像我的Patreon支持者一样通常提前一周看到我的视频。在此感谢我的YouTube会员、X订阅者以及所有其他在片尾字幕中列出的赞助者。感谢大家的支持，谢谢你们收看。