So you want to fast charge your (graphitic anode) EV battery? Charge acceptance is a strong function of temperature for graphite, but it's not simply because D = D(T). Based on this relationship alone the benefit peters out around ~40˚C. 1/n

https://pubs.acs.org/doi/10.1021/acs.jpcc.0c09972 https://twitter.com/CBommier/status/1349490779421478912

This was predicted by some great work by Aurbach and Ceder (separately) in the 00's. But what was new (to us) at least was that at lower temperatures the lowest diffusivity takes a big dip. 2/n

This means that there's a point, we think, where lithium might plate well before a standard CV cutoff at not-too-low temperatures around < 20˚C. This jives with our previous lithium plating and gassing work. 3/n

Long story short, fast charge can be improved with temperature, but for graphite it's a goldilocks story. You want that good good 45˚C porridge. Diminishing returns above that. But 40˚C enables much higher D's. 4/n

Huge ups to @CBommier for starting this work and @wesleykchang for finishing it off. There's a lot here and it's driven a lot of the new work we've done in lab, as well as a few papers published before this. n/n