Application of synergistic action of lithium difluoroxalate and trimethylsilyl borate in high voltage electrolyte
ZHANG Chaoyang
ZHANG Ying
DUAN Junfeng
WAN Haojie
DONG Lei
ZENG Rong
LIU Jianwen
Abstract：In conventional electrolytes,due to the high value of the highest occupied molecular orbital of the main solvent cyclic carbonate,cyclic carbonate is constantly oxidized and decomposed when the char-ging voltage reaches 4.3 V or even higher,and the instability of the electrolyte at high voltages leads to a sudden decrease in the battery capacity.Therefore,the development of high-voltage resistant electrolyte is urgent.In this work,lithium difluoro-oxalate borate(LiODFB)was used to replace part of lithium hexafluorophosphate(LiPF6),and the anode film-forming additive tris(trimethylsilyl)borate(TMSB)was added at the same time,to inhibit the decomposition of the solvent through the synergistic effect of LiODFB and TMSB,and to form a cathode electrolyte interface film containing B—O,Si—O and an ap-propriate amount of LiF,to stabilize the structure of the cathode material,and to improve the stability of the electrolyte in the oxidation of 4.6 V.Based on the above,the designed electrolyte formulation:0.5 mol/L LiPF6+0.5 mol/L LiODFB+FEC∶EMC(1∶3)+TMSB(weight percent 5％)was used.Ap-plied to Li/LiNi0.8Mn0.1Co0.1O2 full cell,the electrolyte-matched cell also has a discharge specific capacity of 131.4 mA·h·g-1 and a capacity retention of 70.3％after cycling 500 cycles at a current density of 1 C at 4.6 V.
Keywords：lithium-ion batterieselectrolytehigh voltage
Publication Date：2025-10-25
Online Publishing Date：2026-08-28(First online date of this platform, not the publication date of the document)
Pages：9( 707-714,755 )