The behaviour of graphite, carbon black, and Li4Ti5O12 in LiBOB-based electrolytes

The film formation behaviour of lithium bis(oxalato)borate (LiBOB), a new electrolyte salt for lithium batteries, on graphite, carbon black and lithium titanate is reported. LiBOB is actively involved in the formation of the solid electrolyte interphase (SEI) at the anode. Part of this formation is an irreversible reductive reaction which takes place at potentials of around 1.75 V vs Li/Li+ and contributes to the irreversible capacity of anode materials in the first cycle. Carbon black interacts strongly with LiBOB-based electrolytes, which results in strong film formation and loss of electronic conductivity within the composite electrode. In LiBOB-based electrolytes the electrode kinetics increase in the order: carbon black << fine particulate graphite similar to metal powder, due to decreased film formation of the conductive additive. The influence of various solvents, surfactant additives, and potential impurities was also studied.