Investigation of the Electrode-Electrolyte Interphase in Ester-Based Electrolytes in NCM523/Graphite Cells

The use of methyl acetate (MA) and propionate (MP) as co-solvents in carbonate/LiPF 6 electrolytes have been investigated LiNi 0.5 Co 0.2 Mn 0.3 O 2 (NCM523)/graphite cells to improve electrochemical performance at low temperature (−20 °C). Consistent with previous investigations, improved was observed all electrolyte formulations containing esters. Detailed ex situ surface analysis the films generated ester-based additives reveal significant changes SEI on graphite upon cycling moderately elevated (45 In presence vinylene carbonate (VC) lithium plating is °C) which leads a thicker solid interface (SEI) 45 °C. Incorporation fluoroethylene (FEC) an additive results generation thin alters structure film NCM523 cathode resulting stable over wide range.