Rechargeable lithium‐hydrogen gas hybrid batteries

The global clean energy transition and carbon neutrality call for developing high‐performance new batteries. Here we report a rechargeable lithium metal ‐ catalytic hydrogen gas (Li‐H) hybrid battery utilizing two of the lightest elements, Li and H. The Li‐H battery operates through redox of H2/H+ on the cathode and Li/Li+ on the anode. The universal properties of the H2 cathode enable the battery to demonstrate attractive electrochemical performance, including high theoretical specific energy up to 2632 Wh kg‐1, discharge voltage of 3 V, round‐trip efficiency of 99.7%, reversible areal capacity of 5~20 mAh cm‐2, all‐climate characteristics with a wide operational temperature range of ‐20 ~ 80 °C, and high utilization of active materials. A rechargeable anode‐free Li‐H battery is further constructed by plating Li metal from cost‐effective lithium salts under a low catalyst loading of < 0.1 mg cm‐2. This work presents a route to design batteries based on catalytic hydrogen gas cathode for high‐performance energy storage applications.