氧化硅基电解液用于稳定水系锌锰电池

1 Introduction

Aqueous zinc-manganese batteries with the advantages of high safety, abundant resources and high energy density, are considered as one of the most promising large-scale energy storage batteries [1-3]. Nevertheless, their practical application still faces challenges, which is mainly due to the deterioration of electrochemical performance of manganese-based cathodes caused by aqueous electrolyte. Fundamentally, the electrochemical stability window (ESW) of aqueous electrolyte is limited by the thermodynamic potential difference between oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) of water. Although the ESW of the salt solution can be expanded relative to the pure water (1.23 V), it still cannot meet the requirements of the battery. On the one hand, the narrow ESW will greatly restrain the operating output voltage of aqueous zinc-manganese batteries and lead to insufficient energy density. On the other hand, the narrow ESW tends to lead to gas generation (e.g., O2 and H2) or electrolyte consumption, which will destroy the structure of the electrodes and result in inferior cycling stability.