Effects of electrolytes additive on the electrochemical performance of Si/disordered carbon composite anode for lithium-ion batteries

Abstract

The effect of vinylene carbonate (VC) as electrolyte additive on the electrochemical performances of the Si/disordered carbon (Si/DC) composite electrode / liquid electrolyte interface was studied in this paper. The electrochemical performances of Si/disordered carbon (Si/DC) composite electrode were systematically investigated by constant current charge-discharge. Field scanning electron microscopy (FSEM) was used to observe the change of electrodes in morphology after given cycle numbers. Cyclic voltammetry and electrochemical impedance spectra (EIS) techniques were employed to understand the influences of different electrolytes on the formation of Solid electrolyte interface(SEI) layers. The electrochemical performances were drastically improved by the introduction of a few percent of VC additive. It was found that the SEI layer formed in VC-containing electrolyte has a better resists to the stress caused by large volume variations associated with lithiation and delithiation reactions. This study highlights the importance of the SEI which governs the electrochemical performances of Si/disordered carbon (Si/DC) composite electrode.

Elastic Interfacial Layer Enabled the High‐Temperature Performance of Lithium‐Ion Batteries via Utilization of Synthetic Fluorosulfate Additive

“…However, densely spaced poly(VC)-based SEI cannot retain large spatial volume uctuation of Si during alloying and dealloying processes with Li. Thus, developing synthetic electrolyte additives that can overcome the limitations of VC and FEC is critically important [16][17][18][19][20][21][22] .…”