Electrochemical impedance study of graphite/electrolyte interface formed in LiBOB/PC electrolyte

The irreversible reduction process at 1.70 V, which is characteristic of LiBOB salt, was confirmed to originate from the reductive decomposition of oxalate ester impurities, and this process is believed to be unrelated to the protective SEI formed by LiBOB electrolytes on graphitic anode. When compared with the corresponding LiPF6-based electrolytes, it was concluded that the alkyl carbonates are not appropriate solvents for LiBOB salt, both in terms of the power and low temperature performances in lithium ion cells.