Crystal plane induced in-situ electrochemical activation of manganese-based cathode enable long-term aqueous zinc-ion batteries

Rapid capacity decay and sluggish reaction kinetics are major barriers hindering the applications of manganese-based cathode materials for aqueous zinc-ion batteries. Herein, the effects of crystal plane on the in-situ transformation behavior and electrochemical performance of manganese-based cathode is discussed. A comprehensive discussion manifests that the exposed (100) crystal plane is beneficial to the phase transformation from tunnel-structured MnO2 to layer-structured ZnMn3O7·3H2O, which plays a critical role for the high reactivity, high capacity, fast diffusion kinetics and long cycling stability. Additionally, a two-stage zinc storage mechanism can be demonstrated, involving continuous activation reaction and phase transition reaction. As expected, it exhibits a high capacity of 275 mAh g−1 at 100 mA g−1, a superior durability over 1000 cycles and good rate capability. This study may open new windows toward developing advanced cathodes for ZIBs, and facilitate the applications of ZIBs in large-scale energy storage system. This work demonstrates the exposed (100) crystal plane can shorten the electrochemical activation process of β-MnO2 cathode for aqueous zinc-ion batteries, and promote its in-situ phase transformation from tunnel-structure to layer-structured ZnMn3O7·3H2O, which effectively guarantee fast diffusion kinetics and long cycling stability. [Display omitted] •β-MnO2 exposed with (100) crystal plane is prepared by a facile hydrothermal method.•The exposed (100) crystal plane endows β-MnO2 with high capacity, fast diffusion kinetics and long cycling stability.•The phase transition from tunnel-structured β-MnO2 to layer-structured ZnMn3O7·3H2O contributes to the superior property.•A two-stage zinc storage mechanism is demonstrated, including activation reaction and phase transition reaction.