Manganese dioxide cathode materials for aqueous zinc ion battery: Development, challenges and strategies

Abstract

The construction of new energy sources and their energy storage systems will be a key part of achieving the goal of green and sustainable development. Aqueous zinc ion batteries (AZIBs) have gradually made significant development in large-scale energy storage with their excellent safety performance, low cost and long cycle life. MnO₂ have become one of the most promising cathode materials for AZIBs due to their high theoretical capacity, wide operating voltage, abundant raw material storage, and low cost. However, the energy storage mechanism of MnO₂ cathode has been controversial, while MnO₂ face inherent issues such as Jahn-Teller effect, poor transport dynamics and severe structure degradation. To make a breakthrough from the perspective of MnO₂ application, a comprehensive understanding of MnO₂ is urgent. Herein, we present the development, challenges and strategies of MnO₂ cathode materials for AZIBs in this review. Specifically, we first introduce the history of the development of MnO₂, from its initial application in alkaline batteries to the current high energy density batteries, followed by the discussions on the crystal structure, energy storage mechanism, main challenges and strategies. Finally, we provide innovative solutions to the bottlenecks in the development of MnO₂, as well as recommendations, conclusions and outlooks for its future research directions. We anticipate that in-depth research on MnO₂ will facilitate the commercialization of the next generation of high-performance AZIBs.