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

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-H₂) battery and acidic manganese-hydrogen (Mn-H₂) 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-H₂ 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.