Impacts of vinyl ethylene carbonate and vinylene carbonate on lithium manganese oxide spinel cathode at elevated temperature

Highlights: • 1 wt.% VEC used as additive to improve cycling performance of LiMn₂O₄/Li cells. • A stable SEI film using VEC electrolyte can be formed. • The stability performance of the LiMn₂O₄ cells using VEC electrolyte is improved. • The exfoliation of LiMn₂O₄ using VEC electrolyt is effectively suppressed. - Abstract: The effects of adding vinylene carbonate (VC) and vinyl ethylene carbonate (VEC) in a 1:1:1 (weight ratio) ethylene carbonate (EC)/diethy carbonate (DEC)/dimethyl carbonate (EMC) on the performance of LiMn₂O₄/Li cells at elevated temperature are studied. Linear sweep voltammetry (LSV), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), inductively coupled plasma-atomic emission spectrometry (ICP-AES), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) were used for the analyses. These results confirm the capability of the 1 wt.% VEC electrolyte additive to more effectively improve the cell cycling performance and stability in the (EC and DEC)-based electrolyte of LiMn₂O₄/Li cells