

Exactly.
The whole reason why lithium is such a good material for cathodes in car batteries is because of its very low mass per cation. So for a Lithium Iron Phosphate battery, the the cathode material is LiFePO4, where the Lithium itself is only 4.4% of the overall mass of the cathode.
So it’s important to remember that although the lithium constitutes a small amount of the total mass of a battery, that swings both ways so that not much is actually needed to build the next battery out of recycled materials.




It’s for showing off the engineering. Lots of robotics competitions focus on different things (throwing balls, kicking soccer balls, moving fast), but BattleBots is definitely the one I’d be most worried about advancing a dangerous line of killer tech.
A humanoid bipedal foot race shows off balance, speed, power efficiency, and things like that.