Low-Cost H2/Na0.44MnO2 Gas Battery for Large-Scale Energy Storage

Hydrogen gas secondary cells are generating significantinterestas a prospective solution for emerging electrical energy storage,owing to their high rechargeability and stability. However, theirapplication is generally hindered by the high cost associated withNi-based cathodes or Pt-based anodic catalysts. Here, we propose alow-cost alkaline H-2/Na0.44MnO2 gasbattery, which involves a Na0.44MnO2 cathodeand an H-2 gas anode in an alkaline electrolyte (6 M NaOH).The operation of the alkaline H-2/Na0.44MnO2 gas battery depends on Na+ insertion/extractionin the Na0.44MnO2 cathode and H+/H-2 conversion in the anode with a NiMoCo-based catalyst. Additionally,within a voltage range of 0.6-1.5 V, the alkaline H-2/Na0.44MnO2 gas battery showcases a significantreversible capacity (95.2 mA h g(-1) at 0.2 C) andan exceptional stability (capacity retention of 81.9% over 500 cyclesat 1 C). With its cost effectiveness, environmental friendliness,and high level of safety, the alkaline H-2/Na0.44MnO2 battery emerges as an appealing choice for scalableenergy storage.