Three‐Component Functional Additive in a LiPF6‐Based Carbonate Electrolyte for a High‐Voltage LiCoO2/Graphite Battery System

Abstract The effectiveness of multicomponent functional additives on the performances of lithium ion batteries has received increasing attention. Tris(2 H ‐hexafluoroisopropyl) borate (THFPB) additive can totally suppress the appearance of a crystallized complex between LiPF 6 and adiponitrile (ADN). Herein, ADN, THFPB, and cyclohexylbenzene are demonstrated to be an effective three‐component functional additive in LiPF 6 ‐based carbonate electrolyte that improves the cyclability and rate capabilities of LiCoO 2 /graphite full cells charged to 4.4, 4.45, and 4.5 V, respectively. By systematic characterization, it is demonstrated rationally that, with the help of the three‐component functional additive, the electrolyte is stabilized and new types of less resistant, thinner, more protective solid–electrolyte interfaces are constructed simultaneously on the surfaces of both electrodes.