Tris(trimethylsilyl)borate as an electrolyte additive for improving interfacial stability of high voltage layered lithium-rich oxide cathode/carbonate-based electrolyte

Abstract Tris(trimethylsilyl)borate (TMSB) is used as an electrolyte additive for high voltage lithium-rich oxide cathode of lithium ion battery. The interfacial natures of Li[Li 0.2 Mn 0.54 N i0.13 Co 0.13 ]O 2 /carbonate-based electrolyte are investigated with a combination of electrochemical measurements and physical characterizations. Charge/discharge tests show that the cyclic performance of Li[Li 0.2 Mn 0.54 N i0.13 Co 0.13 ]O 2 in a mixed carbonate electrolyte is significantly improved by using TMSB. After 200 cycles between 2 V and 4.8 V (vs. Li/Li + ) at 0.5 C rate, the capacity retention of Li[Li 0.2 Mn 0.54 N i0.13 Co 0.13 ]O 2 is only 19% in the blank electrolyte, while it is improved to 74% when 0.5% TMSB is applied. The results from physical characterizations demonstrate that this excellent cyclic performance is attributed to the improved interfacial stability of Li[Li 0.2 Mn 0.54 N i0.13 Co 0.13 ]O 2 /electrolyte due to the thin and protective film generated by TMSB.