Scalable, pH‐Universal, Multimetallic Aerogel Electrocatalysts for Efficient Hydrogen Gas Batteries

Abstract Aqueous hydrogen gas batteries (AHGBs) are demonstrated to possess ultra‐long lifetimes and high reliability, making them highly promising for large‐scale energy storage applications. Consequently, the development of high‐efficiency, low‐cost, and scalable hydrogen oxidation/reduction (HOR/HER) catalytic electrode materials is essential for promoting the industrialization of AHGBs. In this study, a large‐scale processible platinum‐ruthenium‐nickel multimetallic aerogel catalyst is presented with high pH‐universal HOR/HER catalytic activity synthesized by a facile method, exhibiting the potential for industrial‐grade production. Theoretical calculations reveal that the synergistic adsorption on different metal atoms optimizes the reaction path, thus enhancing the catalytic activity. Fabricated with an extremely low loading (≈30 µg PtRu cm −2 ), both alkaline nickel‐hydrogen (Ni‐H 2 ) battery and acidic manganese‐hydrogen (Mn‐H 2 ) battery demonstrate high performance with lifetimes exceeding 2500 h at 0.5 C and over 1500 cycles at 20 C, respectively, significantly surpassing those with commercial Pt/C catalyst. Notably, a 5 Ah scaled‐capacity Ni‐H 2 battery is assembled and exhibits an exceptional energy density of 169 Wh kg −1 with a low cost of US$ 74 kWh −1 based on all components of the cell, providing possibilities for the commercialization of AHGBs in large‐scale energy storage applications in the future.