Using Silica Aerogel Layers for the Stabilization of Zn Metal Anodes in Zn‐Ion Batteries

Abstract

AbstractAqueous zinc ion batteries have the advantages of low cost, high safety, high theoretical specific capacity. However, the charging and discharging process is usually accompanied by side reactions such as dendrite growth, hydrogenolysis, corrosion of electrodes, passivation, etc., which limits the development and application. In this work, the zinc anode is modified by constructing a silica aerogel layer with ultra‐high specific surface area and abundant polar functional groups (−OH, −COOH, −CH3), which not only provides abundant active sites for the uniform deposition of zinc ions, but also construct an artificial protective layer that acting as a desolvation layer and a zinc ion flux regulator. Consequently, the altered zinc anode exhibits an extremely durable zincophilic characteristic and a declining interfacial impedance. The constructed artificial layer can prevent side reactions and promote uniform zinc ion deposition to prevent the generation of zinc dendrites during the charge/discharge process. Results show that the symmetric cells composed of modified Zn anodes can be stably cycled for more than 1100 h at 0.5 mA cm−2 and 0.5 mAh cm−2, which is much higher than that of bare Zn. In addition, the life and capacity retention of the Zn/MnO2 full cells were also significantly improved.