Facile one-step elaboration of nanostructured ZnMn2O4 thin films by a plasma process as a high-performance rechargeable zinc-ion battery cathode

Abstract

The need to develop safe, environmentally-friendly and low cost batteries has led to a growing interest in zinc-ion batteries (ZIBs), due to the abundance of zinc and the high theoretical capacity of this material. For large scale applications, it will be necessary to find adequate cathode materials capable of reversible Zn²⁺ electrochemical storage over prolonged cycling. Among various promising candidates, ZnMn₂O₄ spinel has attracted attention because of its high theoretical capacity, higher voltage than vanadium-based cathodes, and better cyclability among manganese oxide-based cathodes. However, most of the elaboration routes of manganese oxide based cathodes rely on cost-ineffective and time-consuming multi-steps processes. In this work, we report the elaboration of nanostructured thin films of ZnMn₂O₄ spinel using a single step non-equilibrium plasma method without calcination and without using any additives. The electrochemical behavior of the as-deposited ZnMn₂O₄ spinel thin film was studied for application as a cathode in ZIBs. It gave a remarkably high specific capacity of 235 mA h g⁻¹ at 0.1 A g⁻¹ and 155 mA h g⁻¹ after 1100 cycles at a current intensity of 1 A g⁻¹. These electrochemical performance results demonstrate that the plasma-based elaboration process is a promising strategy for the development of advanced next-generation ZIBs based on the use of nanostructured materials with a controlled structure and microstructure.