Constructing Ionic Self‐Concentrated Electrolyte via Introducing Montmorillonite Toward High‐Performance Aqueous Zn−MnO2 Batteries

Abstract Aqueous zinc metal batteries are regarded as one of the most promising alternatives to lithium–ion batteries for large‐scale energy storage due to the abundant zinc resources, high safety, and low cost. Herein, an ionic self‐concentrated electrolyte (ISCE) is proposed to enable uniform Zn deposition and reversible reaction of MnO 2 cathode. Benefitting from the compatibility of ISCE with electrodes and its adsorption on the electrode surface for guidance, the Zn/Zn symmetrical batteries exhibit the long‐life cycle stability with more than 5000 and 1500 h at 0.2 and 5 mA cm −2 , respectively. The Zn/MnO 2 battery also exhibits a high capacity of 351 mA h g −1 at 0.1 A g −1 and can enable a stability over 2000 cycles at 1 A g −1 . This work provides a new insight into electrolyte design for stable aqueous Zn–MnO 2 battery.