Amorphous K-Buserite Microspheres for High-Performance Aqueous Zn-Ion Batteries and Hybrid Supercapacitors.

Aqueous Zn-ion batteries (AZIBs) and Zn-ion hybrid supercapacitors (AZHSCs) are considered promising energy-storage alternatives to Li-ion batteries due to the attractive merits of low-price and high-safety. However, the lack of suitable cathode materials always hinders their large-scale application. Herein, amorphous K-buserite microspheres (denoted as K-MnO ) are reported as cathode materials for both AZIBs and AZHSCs, and the energy-storage mechanism is systematically revealed.