Strategies for solving hydrogen precipitation problems in aqueous zinc ion batteries

Abstract

Aqueous zinc ion batteries have revealed many problems while solving the safety problems of conventional batteries, among which the narrow electrochemical stability window of water causes the battery to be prone to hydrogen precipitation reactions. In this paper, we summarize two strategies to solve the problem. From the electrolyte side, firstly, we use a mixture of salt-in-water electrolyte  to lower the starting potential of hydrogen precipitation reaction, so that the hydrogen precipitation reaction can be inhibited. The second strategy is to use intermolecular forces to configure a high concentration electrolyte to change the presence of ions in the solution, thus reducing the free water content and the activity of water to inhibit the hydrogen precipitation reaction.