Effect of MnO2 Morphology on Kinetics and Stability in Zinc-Ion Batteries.

Abstract

Research on zinc-ion batteries (ZIBs) with manganese-based cathodes has been severely hindered by their poor cycle stability. This study explores the fundamental parameters that affect the cycle stability of battery systems from a structural stability perspective. MnO2 electrodes with different classical morphologies and sizes were synthesized via a temperature-controlled coprecipitation strategy. The effects of the morphology and size of the MnO2 on the overall electrical properties and kinetics of ZIBs were analyzed and compared. The one-dimensional nanofibrous α-MnO2 produced using this method exhibited the most stable nanostructure with a favorable aspect ratio, which resulted in faster chemical kinetics. A more uniform particle distribution and better aspect ratios not only enabled a faster ion migration rate but also affected the remolding of the anode morphology. After 2000 cycles at a high current density of 1 A g-1, the material maintained an excellent discharge-specific capacity, highlighting it as a promising electrode material for ZIBs. The construction of nanoenergy materials with controllable morphologies and sizes will significantly advance battery applications.