Probing the reversibility and kinetics of Li⁺ during SEI formation and (de)intercalation on edge plane graphite using ion-sensitive scanning electrochemical microscopy

Abstract

Tracking down Li+ flux during complex ion intercalation processes on a battery interface.

Model Studies on Solid Electrolyte Interphase Formation on Graphite Electrodes in Ethylene Carbonate and Dimethyl Carbonate II: Graphite Powder Electrodes

“…The results indicated a very low Li + intercalation capacity and the slow and inhomogeneous formation of a passivation film at the basal plane, which was proposed to be dominated by solvent decomposition [22,40,41] . The edge plane, on the other hand, was shown to be active both for preferential salt decomposition [22,40,41] and for Li + (de‐)intercalation [43,44] . Several studies reported exfoliation of the HOPG electrode, most likely induced by solvent co‐intercalation (especially in DMC [15,33] ).…”

“…Numerous electrochemical studies employed HOPG as a model electrode with a low defect site density to investigate the formation and composition of the SEI under structurally well-defined conditions. [14,19,22,[36][37][38][39][40][41][42][43] The results indicated a very low Li + intercalation capacity and the slow and inhomogeneous formation of a passivation film at the basal plane, which was proposed to be dominated by solvent decomposition. [22,40,41] The edge plane, on the other hand, was shown to be active both for preferential salt decomposition [22,40,41] and for Li + (de-)intercalation.…”

“…[22,40,41] The edge plane, on the other hand, was shown to be active both for preferential salt decomposition [22,40,41] and for Li + (de-)intercalation. [43,44] Several studies reported exfoliation of the HOPG electrode, most likely induced by solvent co-intercalation (especially in DMC [15,33] ). Individual, HOPG-supported graphite particles, which were studied by electrochemical atomic force microscopy, displayed an enhanced SEI formation activity and a better cell performance, which was attributed to the higher concentration of defect sites.…”

“…Before presenting and discussing the results, we will briefly summarize previous studies and conclusions relevant for the understanding of our data. Numerous electrochemical studies employed HOPG as a model electrode with a low defect site density to investigate the formation and composition of the SEI under structurally well‐defined conditions [14,19,22,36–43] . The results indicated a very low Li + intercalation capacity and the slow and inhomogeneous formation of a passivation film at the basal plane, which was proposed to be dominated by solvent decomposition [22,40,41] .…”

In-situ/operando characterization techniques in lithium-ion batteries and beyond

“…The common utilization of feedback mode is monitoring the SEI formation and performance on the anodes, such as carbon-based materials, Li, Si and TiO 2 [168][169][170][171][172][173][174][175]. Krueger et al constructed an in-house cell with central hole for the microprobe placement to track the SEI formed on the lithium anode in LiClO 4 /PC electrolyte (Fig.…”