Constructing Ionic Self-Concentrated Electrolyte via Introducing Montmorillonite Toward High-Performance Aqueous Zn-MnO 2 Batteries.

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.