A gas-solid hydride ion battery and a hydrogen-electricity co-storage system

Significant progress has been made in materials development for hydride ion (H − ) conduction and H − -mediated electrochemical devices. However, a gas-solid H − battery (g-HIB) that utilizes H 2 and metals as the active materials of the electrodes and offers the potential for high capacity and energy density has yet to be developed. Here, a typical metal-hydrogen system, Mg-H 2 , is employed to build such a g-HIB. Experimental results validate that hydrogenation and dehydrogenation of the anode lead to electric energy output and input, respectively, in the Mg|3CeH 3 @BaH 2 |H 2 developed. This g-HIB exhibits an initial capacity of 1,526 mAh/g and maintains a capacity retention of over 70% after 60 cycles. It operates effectively across a wide temperature range of −20°C to 90°C. The integration of this g-HIB with a secondary ion battery could create a novel hydrogen-electricity co-storage system that can be applied to hydrogen-electricity powertrains of fuel cell vehicles or drones to deliver a high hydrogen energy efficiency of 93.9%.