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

The effectiveness of multicomponent functional additives on the performances of lithium ion batteries has received increasing attention. Tris(2H-hexafluoroisopropyl) borate (THFPB) additive can totally suppress the appearance of a crystallized complex between LiPF6 and adiponitrile (ADN). Herein, ADN, THFPB, and cyclohexylbenzene are demonstrated to be an effective three-component functional additive in LiPF6-based carbonate electrolyte that improves the cyclability and rate capabilities of LiCoO2/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.