Enabling rechargeable Li‐MnO₂ batteries using ether electrolytes

Abstract

Abstract A low‐carbon future demands more affordable batteries utilizing abundant elements with sustainable end‐of‐life battery management. Despite the economic and environmental advantages of Li‐MnO 2 batteries, their application so far has been largely constrained to primary batteries. Here, we demonstrate that one of the major limiting factors preventing the stable cycling of Li‐MnO 2 batteries, Mn dissolution, can be effectively mitigated by employing a common ether electrolyte, 1 mol/L lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) in 1,3‐dioxane (DOL)/1,2‐dimethoxyethane (DME). We discover that the suppression of this dissolution enables highly reversible cycling of the MnO 2 cathode regardless of the synthesized phase and morphology. Moreover, we find that both the LiPF 6 salt and carbonate solvents present in conventional electrolytes are responsible for previous cycling challenges. The ether electrolyte, paired with MnO 2 cathodes is able to demonstrate stable cycling performance at various rates, even at elevated temperature such as 60°C. Our discovery not only represents a defining step in Li‐MnO 2 batteries with extended life but provides design criteria of electrolytes for vast manganese‐based cathodes in rechargeable batteries.