Effect of Electrolyte Additives on Kinetic Parameters of Lithium-ion Transfer Reactions at Electrolyte/Graphite Interface

The performance of the graphite anode of lithium-ion batteries is greatly affected by the solid electrolyte interphase (SEI) generated at the first charge. However, there are few studies on the kinetics of the lithium-ion intercalation/de-intercalation reaction in graphite to investigate the effect of SEI. In this study, the correlation between the interfacial lithium-ion transfer resistance (Rct) and the double layer capacitance (Cdl) of graphite composite electrodes coated with various SEIs was investigated. It was found that the value of 1/RctCdl was different for each SEI, that is, the frequency (or rate) of intercalation and de-intercalation of lithium ions into graphite was different for each SEI. The activation energy of Rct was almost the same for all the electrolyte solutions. These results indicate that the pre-exponential factor of the Arrhenius equation governing the rate of interfacial ion transfer in a practical graphite anode is dependent on the nature of SEI.