Tesla Cathode Production Patent – LFP Cheaper than China

以下是翻译： The Limiting Factor 的 Jordan Geisigee 分析了特斯拉最近发布的一项专利申请，该申请提供了关于特斯拉正极材料生产过程的见解，特别是针对磷酸铁锂 (LFP) 正极材料。这项自电池日以来历经五年开发的工艺，旨在以低于从中国进口的、需缴纳关税的 LFP 材料的成本，生产正极粉末——高度有序、高纯度的晶体，用于存储锂离子。这可能使特斯拉能够生产全球成本最低的 LFP 电池单元。 该视频重点关注正极粉末本身的制造过程，将其与用于将粉末粘附到电池单元箔上的干法涂布工艺区分开来。 Geisigee 感谢 Battery Bulletin 和 Joe Tegmeyer 对这项分析的贡献。 传统上，正极材料的生产涉及一个复杂的流程，始于化工厂，金属在那里与硫酸混合，生成金属硫酸盐。 这些硫酸盐随后被运送到正极材料厂，并与水和碳酸盐在连续搅拌釜式反应器 (CSTR) 中混合，形成金属碳酸盐颗粒。 这些颗粒经过分离、清洗、过滤、干燥、研磨和按尺寸分类。 最后，将它们与含锂粉末混合、加热并结晶。 这种传统方法存在缺点：它需要单独的化工厂，产生重金属废水，并且由于多个反应步骤和所需的设备，导致资本密集。 特斯拉提出的工艺旨在解决这些问题。 该专利申请内容广泛，包括湿法和干法生产路径以及大量的工艺选项。 通过分析发明人（Bastion Ewald、Ulongleo 和 Anthony Michael Thurston）的工作经历，以及在 Giga Austin 的正极材料工厂安装的设备（由 Joe Tegmeyer 追踪），包括 SACME 压实设备和 Clia SAGR 窑炉，Geisigee 认为特斯拉最有可能采用专利申请图 8 中详述的喷雾造粒工艺。 该工艺首先将所有原始正极材料添加到混合罐 (801) 中，以形成颗粒物的均匀浆料，包括金属、提供活性离子（如锂和钠）的化合物以及 LFP 正极的碳掺杂材料。 这种一步混合消除了对金属硫酸盐的需求，并允许在采购材料方面具有更大的灵活性。 然后将浆料保存在储罐 802 中，然后再输送到造粒机 (803)，这很可能是一台喷雾造粒机。 在这里，在加热的同时喷洒浆料，蒸发水分并导致各个颗粒结合成更大的、团聚的二次颗粒。 接下来，在步骤 807 中，对颗粒进行分类，以确保它们具有适合优化电池性能的正确尺寸。 尺寸过小或过大的颗粒然后通过两条潜在途径回收回工艺中：或者研磨成初级颗粒并返回到造粒机，或者返回到初始混合罐 (801/802) 以重新组合成浆料进料。 喷雾造粒工艺消除了对单独的清洗、过滤和干燥步骤的需求。 该工艺还允许将释放出的水蒸气通过冷凝器并重复使用。 尺寸正确的颗粒随后被送到炉子或窑炉中进行煅烧——在氮气（对于 LFP）或氧气（对于高镍 NMC）气氛中加热和结晶。 虽然该专利显示了一种旋转炉，但特斯拉在奥斯汀安装了一个 Sagar 辊底窑，这表明 Sagar 窑要么用于测试批次，要么是主要的生产方法。 最后，在炉子之前可能会使用压力机或压实机将材料压入坩埚中，或者在窑炉之后将正极粉末解聚，尽管 Geisigee 倾向于后者。 该专利的主要创新是“一锅法”，即一步混合所有原材料，以及废料回收的再循环途径。 这些特性对于实现特斯拉在电池日宣扬的环境和成本效益至关重要。 虽然特斯拉的工艺在五年前可能提供了高达 76% 的成本降低，但目前中国的 LFP 生产也采用了喷雾干燥工艺。 然而，尚不清楚中国的工艺是否允许固体废物的回收利用，并且它使用效率较低的 Sagar 窑。 虽然特斯拉可能保留了一些优势，但中国制造商正在赶上。 然而，这并不是一个主要问题，因为即使中国正极粉末的生产达到特斯拉的成本水平，特斯拉也将受益于避免关税和运输成本。 结论是，特斯拉的工艺可以控制其供应链，确保成本效益，并且在与 Nano 1 等公司打交道时，可能会提供更强大的议价能力，如果存在任何专利重叠的话。 后续视频将探讨该专利对 LFP4680 电池的更广泛影响，该电池据推测将用于 CyberCab。

Jordan Geisigee of The Limiting Factor analyzes a recently published Tesla patent application providing insights into Tesla's cathode material production process, particularly for LFP (Lithium Iron Phosphate) cathode material. This process, developed over five years since Battery Day, aims to produce cathode powder – highly ordered, high-purity crystals that store lithium ions – at a lower cost than tariffed LFP material from China. This could enable Tesla to produce some of the lowest-cost LFP battery cells globally. The video focuses on the process for making the cathode powder itself, distinguishing it from the dry coating process used to adhere the powder to battery cell foils. Geisigee credits Battery Bulletin and Joe Tegmeyer for their contributions to the analysis. Traditionally, cathode production involves a complex process starting at a chemical plant, where metal is mixed with sulfuric acid to create metal sulfates. These sulfates are then transported to the cathode plant and mixed with water and carbonates in a continuously stirred tank reactor (CSTR) to form metal carbonate particles. These particles are separated, washed, filtered, dried, ground, and classified by size. Finally, they're mixed with lithium-containing powder, heated, and crystallized. This traditional method has drawbacks: it requires a separate chemical plant, generates heavy metal wastewater, and is capital-intensive due to the multiple reaction steps and equipment required. Tesla's proposed process aims to solve these problems. The patent application is extensive, featuring wet and dry production paths and numerous process options. By analyzing the work history of the inventors (Bastion Ewald, Ulongleo, and Anthony Michael Thurston) and the equipment installed at Giga Austin's cathode factory (tracked by Joe Tegmeyer), including SACME compacting equipment and Clia SAGR kilns, Geisigee believes Tesla is most likely employing a spray granulation process detailed in Figure 8 of the patent application. This process starts by adding all raw cathode materials into a mixing tank (801) to create a homogenous slurry of particulate matter, including metals, compounds supplying active ions like lithium and sodium, and materials like carbon doping for LFP cathodes. This single-step mixing eliminates the need for metal sulfates and allows for greater flexibility in sourcing materials. The slurry is then held in Tank 802 before being fed to a granulator (803), which is likely a spray granulator. Here, the slurry is sprayed while being heated, evaporating water and causing the individual particles to combine into larger, agglomerated secondary particles. Next, at step 807, the particles undergo classification to ensure they are of the correct size for optimal battery performance. Undersized or oversized particles are then recycled back into the process via two potential pathways: either being milled into primary particles and returned to the granulator, or being returned to the initial mixing tank (801/802) to be recombined into the slurry feed. The spray granulation process eliminates the need for separate washing, filtering, and drying steps. This process also allows for the water that's off-gassed to be run through a condenser and reused. Particles of the correct size are then sent to a furnace or kiln for calcination – heating and crystallizing in a nitrogen (for LFP) or oxygen (for high-nickel NMC) atmosphere. While the patent shows a rotary furnace, Tesla installed a Sagar roller hearth kiln at Austin, suggesting either the Sagar kiln is for test batches or the primary production method. Finally, presses or compactors are potentially used to pack the material into crucibles before the furnace or to de-agglomerate the cathode powder after the kiln, though Geisigee leans towards the latter. Key innovations from the patent are the "one-pot process," combining all raw materials in one step, and the recirculation pathway for waste material recycling. These features are crucial for achieving the environmental and cost benefits Tesla touted at Battery Day. While Tesla's process may have provided a significant 76% cost reduction five years ago, current LFP production in China also employs spray drying processes. However, it is not clear the Chinese process allows for waste recycling of solids, and it utilizes less efficient Sagar kilns. While Tesla may retain some advantages, Chinese manufacturers are catching up. However, this is not a major concern because even if Chinese cathode powder production reaches Tesla's cost level, Tesla will benefit from avoiding tariffs and transportation costs. The conclusion is that Tesla's process allows control over its supply chain, ensures cost-effectiveness, and potentially gives a stronger bargaining position when dealing with companies like Nano 1, should there be any patent overlap. The subsequent video will explore the broader implications of this patent for the LFP4680 battery, speculated to be used in the CyberCab.