Jordan Geisigee of The Limiting Factor analyzes the potential for Tesla to produce and utilize an LFP (Lithium Iron Phosphate) 4680 battery cell, specifically for the CyberCab. He dives deep into whether an LFP 4680 battery is plausible considering common perceptions that LFP chemistry is better suited for prismatic form factors due to their lower energy density. Despite this apparent limitation, Geisigee argues that an LFP 4680 presents a compelling case, primarily driven by cost savings, longevity, and supply chain considerations.
He starts by stating that Tesla is probably working on manufacturing their own LFP batteries. He refers to a patent application detailing Tesla's cathode production process, explicitly mentioning the production of LFP cathode material. He backs this up with former Tesla executive Drew Baglino's comment suggesting that US and European LFP supply chains should adopt Tesla's patented approach to reduce costs compared to importing from China. Further investigation into the inventors reveals that Tesla has run multiple pilot and production trials of LFP cathode material, indicating a serious intent to commercialize in-house LFP cell production.
Addressing the form factor debate, Geisigee re-examines past statements from Tesla regarding LFP batteries. He acknowledges Elon Musk and Drew Baglino's comments suggesting that 4680 is not the ultimate form factor for everything, particularly iron-based cells. However, he interprets this not as a complete rejection of LFP 4680, but rather as a consideration of the optimal form factor based on specific use cases.
Geisigee references a report that Tesla plans on introducing four versions of the 4680 cell, including a workhorse cell for the CyberCab, which an LFP chemistry is best suited for.
He acknowledges that Tesla may be purchasing equipment from CATL to produce prismatic LFP cells for megapacks. While acknowledging the possibility of using the prismatic cells for EVs, he considers it less likely given the difference in cell size requirements between grid storage and EV applications. EV battery packs require smaller cells wired in series to achieve high voltage, while megapacks can use larger cells.
The core argument for the LFP 4680 revolves around cost. Geisigee asserts that the primary requirement for the CyberCab battery pack will be cost per kilowatt-hour per cycle, meaning the cheapest battery with the highest cycle life will win. An LFP 4680 could potentially excel in this metric, combining the lowest cost chemistry with a relatively low-cost cylindrical form factor and Tesla's potentially lower-cost dry electrode coating manufacturing process.
Geisigee addresses the cost disadvantages of an LFP 4680, like the need for more cells and welds in a pack due to smaller cell size, and China’s dominance over refined battery materials. However, he argues that the cost from additional welding would be minimal, and that Tesla's vertical integration efforts aim to reduce costs associated with shipping, tariffs, and profit margins. Ultimately, a Tesla LFP 4680 pack is posed to be one of the cheapest EV battery packs available.
He examines the long-term cost implications of using nickel-based cells versus LFP, specifically regarding electricity consumption due to the lower energy density of LFP. His calculations show a slight cost advantage for nickel cells in terms of electricity savings, but this is offset by the higher initial cost of a nickel battery pack, especially when the longer cycle life of LFP is factored in. He also points out that Tesla could apply improvements to make high-cycle life nickel cells to making LFP cells last even longer, reducing their cost per kilowatt-hour per cycle even further.
Geisigee notes that LFP batteries are cobalt free, making them more publicly palatable than cobalt-containing nickel batteries. Also, LFP cathodes are nontoxic, potentially reducing the long-term environmental impact of disposal, however, like nickel battery packs, they would still be recycled for other valuable materials. The author also notes that Tesla has patented a hybrid cathode by adding a small amount of cobalt-free nickel material (2-3% of the cathode) it would increase the cycle life without adding significant cost.
Geisigee addresses the issue of lower energy density in LFP cells, estimating that an LFP-equipped vehicle would have approximately 63% of the range of a comparable vehicle using nickel-based cells. However, he points out that Tesla's vehicles are engineered for high efficiency and that adjustments can be made to compensate for the lower energy density. He believes a cybercab using LFP 4680 cells could have more than 300 miles of range, more than Tesla’s goal of 200 miles of range.
Finally, he lists other advantages of LFP 4680 cells, including their inherent safety, potential for structural rigidity, ease of temperature control, and durability for commercial duty cycles. He concludes that an LFP 4680 could be the lowest cost, safest, and most durable battery pack. He predicts that if Tesla’s nickel-based 4680 cell ramp-up goes well, a LFP 4680 could be seen next year.