Hydrolysis Batteries: Generating Electrical Energy during Hydrogen Absorption

The hydrolysis reaction of aluminum can be decoupled into a battery by pairing an Al foil with a Pd-capped yttrium dihydride (YH₂–Pd) electrode. This hydrolysis battery generates a voltage around 0.45 V and leads to hydrogen absorption into the YH₂ layer. This represents a new hydrogen absorption mechanism featuring electrical energy generation during hydrogen absorption. The hydrolysis battery converts 8–15 % of the thermal energy of the hydrolysis reaction into usable electrical energy, leading to much higher energy efficiency compared to that of direct hydrolysis.