Alternative Multifunctional Cyclic Organosilicon as an Efficient Electrolyte Additive for High Performance Lithium-Ion Batteries

[Display omitted] Multifunctional ViD4 with vinyl group and Si-O bond is an efficient electrolyte additive for preparing the advanced Lithium-ion batteries. •Three kinds of functional organosilicons are investigated as electrolyte additives for LIBs.•3D surface plot is firstly used to evaluate the cycling performance of LIBs.•ViD4 improved cycling stability of NCM622/Li cells at a high potential.•ViD4 has a significant influence on the formation of a stable CEI film. Three kinds of functional organosilicons electrolyte additives, i. e. octamethylcyclotetrasiloxane (D4), octamethylcyclotetrasiloxane (OMCTS) and 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetra- siloxane (ViD4), are firstly used to produce high-performance LiNi0.6Co0.2Mn0.2O2 cathode for rechargeable Lithium-ion batteries (NCM622/Li half-cell) at a high potential. The electrochemical performance tests at 4.5V suggest that ViD4 is the most promising electrolyte additive than its counterparts. Moreover, the prepared NCM622/Li half-cell with 0.5wt.% ViD4 exhibits an improved energy density of 187.2mAhg−1 and a good discharge capacity retention of 83.6% at 1C rate after 150 cycles at 4.5V, which is relatively higher than that with D4 (81.3%), OMCTS (81.9%) and much better than the bare electrolyte (76.1%). The electrochemical characterizations, density functional theory calculation and surface analysis provide strong evidences that combined effects of the Si-O bond and vinyl functional group in ViD4 can promote the formation of a uniform cathode electrolyte interphase (CEI) film. Moreover, the ViD4-incorporated CEI film effectively enhances the interfacial stability between the NCM622 cathode and the electrolyte by suppressing the continuous decomposition of carbonate-based electrolyte and the exfoliation of these decomposition products. Hence, the ViD4-containing electrolyte shows a promising potential for the application in high energy density lithium-ion batteries.