Low-Cost H₂/Na_0.44MnO₂ Gas Battery for Large-Scale Energy Storage

Hydrogen gas secondary cells are generating significant interest as a prospective solution for emerging electrical energy storage, owing to their high rechargeability and stability. However, their application is generally hindered by the high cost associated with Ni-based cathodes or Pt-based anodic catalysts. Here, we propose a low-cost alkaline H 2 /Na 0.44 MnO 2 gas battery, which involves a Na 0.44 MnO 2 cathode and an H 2 gas anode in an alkaline electrolyte (6 M NaOH). The operation of the alkaline H 2 /Na 0.44 MnO 2 gas battery depends on Na + insertion/extraction in the Na 0.44 MnO 2 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 /Na 0.44 MnO 2 gas battery showcases a significant reversible capacity (95.2 mA h g –1 at 0.2 C) and an exceptional stability (capacity retention of 81.9% over 500 cycles at 1 C). With its cost effectiveness, environmental friendliness, and high level of safety, the alkaline H 2 /Na 0.44 MnO 2 battery emerges as an appealing choice for scalable energy storage.