Bi‐affinity Electrolyte Optimizing High‐Voltage Lithium‐Rich Manganese Oxide Battery via Interface Modulation Strategy

Abstract

AbstractThe practical implementation of high‐voltage lithium‐rich manganese oxide (LRMO) cathode is limited by the unanticipated electrolyte decomposition and dissolution of transition metal ions. The present study proposes a bi‐affinity electrolyte formulation, wherein the sulfonyl group of ethyl vinyl sulfone (EVS) imparts a highly adsorptive nature to LRMO, while fluoroethylene carbonate (FEC) exhibits a reductive nature towards Li metal. This interface modulation strategy involves the synergistic use of EVS and FEC as additives to form robust interphase layers on the electrode. As‐formed S‐endorsed but LiF‐assisted configuration cathode electrolyte interphase with a more dominant −SO2− component may promote the interface transport kinetics and prevent the dissolution of transition metal ions. Furthermore, the incorporation of S component into the solid electrolyte interphase and the reduction of its poorly conducting component can effectively inhibit the growth of lithium dendrites. Therefore, a 4.8 V LRMO/Li cell with optimized electrolyte may demonstrate a remarkable retention capacity of 97 % even after undergoing 300 cycles at 1 C.