> There is an interview with Siddharth Kara that suggests all lithium batteries contain cobalt and thusly depend on child slave labor
That is demonstrably not true. AFAIK the majority of EVs use LFP batteries that have no cobalt. The current RWD Model 3 in the US also uses LFP. That's the direction most EVs will probably head over the next few years.
Lithium iron phosphate are not widely used in EVs. They gave poorer energy density, so lithium ion is preferred. I think electric golf carts use LiFePo batteries, to keep costs low and because range is less of an issue.
LFP batteries have not been widely used outside China till now because CATL[1] owns the important patents. The patents expire this year.
The energy density discrepancy is not as bad at a system (whole vehicle) level as it appears at cell level, for various reasons. And there are lots of use cases where LFP has more than enough energy, provided the price is right.
The vast majority of EVs in China use LFP, and China has most of the EVs in the world. And even in the US, by volume I wouldn't be surprised if the RWD Model 3 is a reasonable fraction of total EV sales.
The energy density is partially offset by the higher cycle life of LFP even while charging to 100% SOC.
For instance Tesla recommends an 80% charge for daily unless you know you are going to go a long trip, while on their LFP version they recommend a 100% daily charge to keep cell balance as the LFP pack will have a much longer life than a NCM pack at 80%.
It's not just LFP batteries that don't use cobalt. Tesla's medium density batteries use a "high nickel" cathode rather than a nickel-manganese-cobalt cathode.
I'd like to learn more about that but I am coming up blank. Everything I've found suggests even the new Tesla 4680 continues to rely on some amount of cobalt.
That is demonstrably not true. AFAIK the majority of EVs use LFP batteries that have no cobalt. The current RWD Model 3 in the US also uses LFP. That's the direction most EVs will probably head over the next few years.