Awhile back, I was working on an R&D contact for the US Army for a hybrid battery. Our R&D side was a zinc air battery, AA sized and configured in multiples. Zinc Air batteries are old hat, used in hearing aids (your local drug store has some). Zinc air batteries use the oxygen in the air as one of the active components. A layer of micro-porous Teflon allows the oxygen into the battery, but contains the other ingredients. Long life, as a portion of the battery is not needed to be packaged in the battery, but they're not typically rechargeable.
The Army wanted a battery that a soldier could walk/swim into/cross a river. Ya need air underwater. Ditto on a zinc air battery. These batteries were envisioned to be located on a hip pouch. So the Army research group came up with lithium batteries paired with the zinc air. From the data I saw, it looked very effective.
Hybrid food crops, cars, animal breeds.....why not hybrid batteries?
I watched the video and found the presenter knowledgeable and likely spot on.....technically, except for the complexities involved of this marriage of battery chemistries . Oh..... aren't all marriages complex? Batteries too.