> Lithium ion not good enough, find we'll find a better battery. Well, then get back to us when you find that battery. Unfortunately, simply finding a new batt

> Lithium ion not good enough, find we'll find a better battery. Well, then get back to us when you find that battery. Unfortunately, simply finding a new battery chemistry that has an order of magnitude better energy density is easier said than done. > Hydrogen however is just that: hydrogen. Notice how low it is on the energy per volume scale. You're looking at uncompressed hydrogen. Hydrogen at 700 bar has several times better energy density than lithium ion batteries, and over 1000x as much energy by mass. And lower mass means you need less fuel since the craft is lighter.