In the quest to increase energy density of lithium-ion cells, graphite-silicon composite electrodes have been extensively investigated. The long-term performance of these electrodes is limited due to the instability of the electrode-electrolyte interface that is continually disrupted during the charge-discharge cycles. In order to improve the performance of silicon-based negative electrodes, researchers have developed various strategies that include novel electrolyte formulations among many others.

We conducted a comparative study of several electrolyte formulations based on LiFSI, LiTFSI, LiPF6, and mixtures thereof  in fluorinated carbonates like methyl 3,3,3-trifluoroethyl carbonate, bis(3,3,3-trifluoroethyl) carbonate, 3,3,3-trifluoropropylene carbonate, and monofluoropropylene carbonate.

Comprehensive data from rate study, impedance and cycle life evaluation in NCM523//Gr-Si CR2032 full cells will be presented and discussed.