When a lithium-air battery is discharged, lithium ions normally react with oxygen at the positive electrode, but when the positive electrode potential drops significantly, water in the electrolyte reacts with lithium ions to generate hydrogen. In this study, we proposed a new system for high-density energy storage and hydrogen supply using lithium by utilizing the structure of lithium-air batteries and this working principle, and conducted basic experiments. As a result, it was confirmed that a large overvoltage is involved for the hydrogen production reaction compared to the theoretical potential. In addition, the formation behavior of hydrogen bubbles was observed, and it was confirmed that the almost spherical bubbles were generated in this experimental system. In the future, we will investigate the detailed causes of the overvoltage and hydrogen production behavior in the hydrogen production reaction and propose methods to reduce the overvoltage in order to improve the efficiency of hydrogen production.