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 MnO 2 to layer-structured ZnMn 3 O 7 ·3H 2 O, 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. • β-MnO 2 exposed with (100) crystal plane is realized via controlling the concentration of KCl precursor during the hydrothermal process. • The exposed (100) crystal plane endows β-MnO 2 with high capacity, fast diffusion kinetics and long cycling stability. • Its superior properties can be attributed to the phase transition reaction from tunnel-structured β-MnO 2 to layer-structured ZnMn 3 O 7 ·3H 2 O. • A two-stage zinc storage mechanism can be demonstrated, involving continuous activation reaction and phase transition reaction.