Solvated Lithium Ion Intercalation Behavior of Graphitized Carbon Nanospheres

Abstract

To prolong durability of lithium-ion batteries, stability of solid electrolyte interphase (SEI) formed at a graphite negative electrode should be improved, but the correlation of the SEI stability with the graphite structure is still unclear. This study focused on co-intercalation of dimethoxyethane (DME) into SEI-covered graphitized carbon nanosphere (GCNS) to investigate SEI degradation behavior. In situ Raman spectroscopy revealed that both ethylene carbonate (EC)-derived and propylene carbonate (PC)-derived SEIs partly passivated the DME co-intercalation, but the PC-derived SEI degraded more rapidly than the EC-derived one. Additionally, the SEI at GCNS heat-treated at 2900°C had less stability than that at GCNS heat-treated at 2600°C, which is attributable to the graphite layer stacking and surface morphology.