Awesome article! However, while it is definitely reasonable to say that battery costs will converge to material costs, the chart does not show material costs. It shows chemical costs, i.e. costs of active materials and electrolyte. The original reference is this paper from Yet-Ming Chiang (https://www.sciencedirect.com/science/article/pii/S2542435117300326#appsec2).

This is important because the cost of the non-active materials (e.g. separator and current collectors) are definitely non-trivial. When you dig into cost models for Li-ion style batteries, it becomes evident that energy stored per unit area of electrode becomes a major cost factor since this determine the amount of separator and current collector you need. Chemistries that can store more energy in less material (e.g. NMC) are therefore able to have significantly less non-active material than others, and this can make all the difference in material cost. LFP Li-ion may have lower potential chemical cost, but its lower energy density means it needs more electrode area and, therefore, necessarily has a higher non-active material cost component. I've seen commonly adopted LFP with a cell level volumetric energy density ~50% that of NMC, so unless they are included crazy thick separators, its reasonable to think that they have way more electrode area than NMC. This would limit LFP's potential for cost reduction.

Storage duration also becomes super important when considering non-active materials. The chemical cost (capacity) of most flow chemistries are super low but the cost of the cell where the reaction takes place (determines power) is not trivial. Looking at the chemical cost as displayed on the chart, one would expect Zn-Br to replace Li-ion in all stationary applications. If non-active materials are considered, however, you would see that Li-ion has way better material costs for moderate storage duration while something like Zn-Br only pencils out for long duration, i.e. low power and lower non-active material cost.

Still, super cool article! Excited to see your post about zinc chemistries. I work at a zinc-ion start-up, so it's really nice to see the diversity of zinc batteries being covered in media.

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Call me crazy, but the ultimate advance in clean energy of the next 30 years will be asteriod mining! Its a fair to say that focusing on extra-terestrial solutions to climate change is counter productive; like setting 2050 weight loss goals. But think about this for a moment:

-Imagine the core of a proto planet being dragged into orbit around mars

Or to phraze it another way, imagine every 26 months, the global supply of nickel, cobalt, gold ,silver, and hundreds of rare elements increases by a factor of ten. Call me crazier, Biden should use the bottomless pit that is the US military budget and put the space force to this task as part of his whole government approach to climate change

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