Raman Spectroscopy for LiNi_1/3Mn_1/3Co_1/3O₂ Composite Positive Electrodes in All-Solid-State Lithium Batteries

Abstract

Raman spectroscopy was conducted for LiNi_1/3Mn_1/3Co_1/3O₂ (NMC) composite positive electrodes in all-solid-state batteries using Li₂S-P₂S₅ solid electrolytes. Raman spectral changes attributable to structural changes of NMC were observed during the initial charge-discharge test. To evaluate state-of-charge (SOC) distributions in the NMC electrodes, Raman mapping was carried out for the electrodes of charged and discharged cells. The mapping images indicated that most NMC particles were uniformly delithiated and lithiated by the charge-discharge process. It is noteworthy that uniform charge-discharge reactions proceeded in the NMC electrodes.