A rechargeable, non-aqueous manganese metal battery enabled by electrolyte regulation

Owing to their high volumetric capacity, reasonably low redox potential, and budget friendliness, manganese metal batteries (MnMBs) are excellent candidates for batteries with a high energy-to-price ratio. However, since there is no suitable electrolyte ensuring reversible Mn plating/stripping due to the low redox potential of the Mn2+/Mn redox couple and the strong interaction between charge-dense Mn2+ ions and solvents, the development of MnMBs has been largely constrained. Herein, a halogen-mediated non-aqueous electrolyte (HM-NAE) is developed to enable highly reversible Mn plating/stripping. Benefiting from this halogen-mediated mechanism, the asymmetric Mn cell can cycle stably more than 1,000 h with a Coulombic efficiency close to 100%. Moreover, a Mn|HM-NAE|Mo6S8 full cell with high electrochemical performances is constructed and fully understood. This work offers a new avenue to the development of rechargeable, non-aqueous MnMB through electrolyte engineering, which can also shed light on other multivalent metal batteries and electroplating industry.