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

Abstract

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 (R ct ) and the double layer capacitance (C dl ) of graphite composite electrodes coated with various SEIs was investigated. It was found that the value of 1/R ct C dl 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 R ct 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.

Kinetics of Interfacial Ion Transfer in Lithium-Ion Batteries: Mechanism Understanding and Improvement Strategies

“…It was shown that the R ct at the f edge -defined HOPG was in the order of VC > EC > FEC. A similar trend was observed for graphite composite electrodes . Because the evaluated E a was the same for the three SEIs, the variation in the R ct was purely derived from the A .…”

“…A similar trend was observed for graphite composite electrodes. 30 Because the evaluated E a was the same for the three SEIs, the variation in the R ct was purely derived from the A. Hence, the A was in the order of VC < EC < FEC.…”

“…First, we focus on interfacial Li + transfer at transition metal oxides , as positive electrodes and Li 4 Ti 5 O 12 and graphite as negative electrodes. After that, we introduce a detailed analysis on a model interface, solid electrolyte/liquid electrolyte, to discuss the mechanism and rate-determining step. − For graphite negative electrodes, the effects of electrolyte composition and solid electrolyte interphase (SEI) were also studied. − In the latter part, we present strategies to accelerate the interfacial Li + transfer with an eye to electrolyte compositions, surface modifications, and types of battery reactions. − Finally, we emphasize the importance of frequency factors (i.e., pre-exponential factors) as well as activation energies to dominate the kinetics of interfacial Li + transfer. − …”

Preface for the 66th Special Feature “Novel Aspects and Approaches to Experimental Methods for Electrochemistry”

“…219 He started his academic career as the assistant professor in 2017. As well as continuous studies on oxygen electrocatalysis, 220,221 his current research focuses on lithium-ion batteries 60,222,223 and other rechargeable batteries. One of the papers published in Electrochemistry has received Excellent Paper Award of ECSJ in 2021.…”

Edge Structure and Formation of a Solid Electrolyte Interphase Film in Amorphous Carbon-Coated Spheroidized Graphite

“…4,5 The SEI film suppresses the reductive decomposition of the electrolyte on the graphite surface after initial charging and prevents the exfoliation of the graphite surface by suppressing the cointercalation of lithium-ionsolvated compounds. 6 Various structures of SEI films have been reported, 5,7−10 influenced by the type of electrolytes, 11,12 electrolyte additives, 13,14 surface coating layers, 15,16 and charging−discharging conditions. 17,18 Graphite particles coated with an amorphous carbon layer are most commonly used in practical LIBs.…”