Solid–Liquid–Gas Management for Low-Cost Hydrogen Gas Batteries

• Published in: ACS nano Vol. 17; no. 8; pp. 7821 - 7829
• Main Authors: Jiang, Taoli, Wei, Shuyang, Li, Linxiang, Zheng, Kai, Zheng, Xinhua, Park, Sunhyeong, Liu, Shuang, Zhu, Zhengxin, Liu, Zaichun, Meng, Yahan, Peng, Qia, Feng, Yuancheng, Chen, Wei
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 25-04-2023
• Subjects: hydrogen gas batteries; HER/HOR catalysis; solid−liquid−gas management; low-cost hydrogen catalysts; large-scale energy storage
• ISSN: 1936-0851; 1936-086X
• DOI: 10.1021/acsnano.3c00798

Aqueous nickel-hydrogen gas (Ni-H2) batteries with excellent durability (>10,000 cycles) are important candidates for grid-scale energy storage but are hampered by the high-cost Pt electrode with limited performance. Herein, we report a low-cost nickel-molybdenum (NiMo) alloy as an efficient bifunctional hydrogen evolution and oxidation reaction (HER/HOR) catalyst for Ni-H2 batteries in alkaline electrolytes. The NiMo alloy demonstrates a high HOR mass-specific kinetic current of 28.8 mA mg–1 at 50 mV as well as a low HER overpotential of 45 mV at a current density of 10 mA cm–2, which is better than most nonprecious metal catalysts. Furthermore, we apply a solid–liquid–gas management strategy to constitute a conductive, hydrophobic network of NiMo using multiwalled carbon nanotubes (NiMo-hydrophobic MWCNT) in the electrode to accelerate HER/HOR activities for much improved Ni-H2 battery performance. As a result, Ni-H2 cells based on the NiMo-hydrophobic MWCNT electrode show a high energy density of 118 Wh kg–1 and a low cost of only 67.5 $ kWh–1. With the low cost, high energy density, excellent durability, and improved energy efficiency, the Ni-H2 cells show great potential for practical grid-scale energy storage.