Lattice-Mismatched RuNi Alloy Nanoparticles with Enhanced Bifunctional Hydrogen Electrocatalysis for Nickel-H2 Batteries

Abstract

Abstract Nickel-hydrogen gas (Ni-H2) batteries exhibit ultra-long cycle life, promising excellent prospects for applications in large-scale energy storage. However, traditional Pt-based catalysts face challenges in achieving both high activity and long-term stability in alkaline media, rendering the development of electrocatalysts with enhanced performanced for both hydrogen evolution reaction (HER) and hydrogen oxidation reaction (HOR) a significant challenge. In this work, through a combination of rotary evaporation and thermal treatment, the optimized carbon-supported RuNi alloy nanoparticles (RuNi-1/C) have been synthesized, which enables to successfully realize a large lattice mismatch of up to 13.47%. This high lattice mismatch induces change in the interplanar spacing of Ru and Ni, thereby exposing more active sites and resulting in excellent bifunctional HER/HOR performance: it achieves an ultra-low overpotential of just 14.4 mV at a current density of 10 mA/cm2 for the HER and a high exchange current density of 2.13 mA/cm2 at an overpotential of 50 mV for the HOR. Furthermore, when employed as the bifunctional catalyst in a Ni-H2 battery, RuNi-1/C delivers a coulombic efficiency of 92% and outstanding cycling stability. This work offers a promising synthesis route toward the development of highly active and durable bifunctional catalysts by regulating the lattice mismatch.

The authors' abstract, as published at the source. ACS Applied Energy Materials, 2026 · DOI ↗