Interface Engineering of Aqueous Zinc/Manganese Dioxide Batteries with High Areal Capacity and Energy Density

Commercialization of aqueous batteries is mainly hampered by their low energy density, owing to the low mass loading of active cathode materials. In this work, a MnO₂ cathode structure (MnO₂ /CTF) is designed to modify the MnO₂ /collector interface for enhanced ion transportation properties. Such a cathode can achieve ultrahigh mass loading of MnO₂ , large areal capacity, and high energy density, with excellent cycling stability and rate performance. Specifically, a 0.15 mm thick MnO₂ /CTF cathode can realize a mass loading of 20 mg cm^-2 with almost 100% electrochemical conversion of MnO₂ , providing the maximum areal capacity of 12.08 mA h cm^-2 and energy density of 191 W h kg^-1 for Zn-MnO₂ /CTF batteries when considering both cathode and anode. Besides the conventional low energy demonstrations, such a Zn-MnO₂ /CTF battery is capable of realistic applications, such as mobile phones in our daily life, which is a promising alternative for wearable electronics.