SEI film formation on highly crystalline graphitic materials in lithium-ion batteries

In situ differential electrochemical mass spectrometry (DEMS) was used to study the SEI film formation on highly crystalline TIMREX ® SLX50 graphite negative electrodes during the first electrochemical lithium insertion using either 1 M LiPF 6 in ethylene carbonate (EC) with either dimethyl carbonate (DMC) or propylene carbonate (PC) as co-solvent. In the case of the propylene and ethylene carbonate containing electrolyte, DEMS measurements indicate strong formation of ethylene and propylene gas below 0.75 V versus Li/Li +, which does not decrease a ethylene gas f show s e formation o mation at t ate additive. W process of g negative e ©