Large‐Capacity Rechargeable Silicon–Hydrogen Gas Battery

ABSTRACT Silicon (Si) is an important energy storage material that promotes the development of advanced battery technology. At present, Si as an anode has been widely explored in theory and experiment, but its performance in energy storage has not yet reached the theoretical capacity limit. Here, we design a new silicon–hydrogen gas (Si–H 2 ) battery combining the alloying reaction of nano Si anode with the hydrogen evolution and oxidation reactions (HER/HOR) of hydrogen gas (H 2 ) cathode. Systematic electrochemical studies show that the Si–H 2 battery has a discharge capacity of ∼3400 mAh g −1 with a discharge voltage of ∼2.45 V, and a lifetime of more than 100 cycles. The Si–H 2 battery also efficiently operates from 10°C to 80°C with excellent electrochemical performance. It can achieve high‐rate charge and discharge of 8 C at 60°C, and can stably cycle for more than 500 h. This work provides a new concept for promoting the application of hydrogen battery in energy storage and improving the capacity utilization of Si.