Tesla uses their own 7071 lithium ion, just a tad bigger in dimensions but with 30 to 50% more capacity than the 18680 in common usage
Is it volatile, does it need cooling like the car battery bank? Different types of lithium ion batteries have different traits, pluses and minuses, the higher energy density ones are the kind that can catch fire. I haven’t kept up, other than knowing they’re on the market or close with the Tesla Wall.