Understanding corrosion behavior of aluminum current collector in LiFSI electrolyte

Cycling aging is the one of the main reasons affecting the lifetime of lithium-ion batteries and the contribution of aluminum current collector corrosion to the ageing is not fully recognized. In general, aluminum is corrosion resistant to electrolyte since a non-permeable surface film of alumina is naturally formed. However, corrosion of aluminum current collector can still occur under certain conditions such as lithium bis(fluorosulfonyl)imide (LiFSI)-based electrolyte or high voltage. Herein, we investigates the corrosion of aluminum current collector in the electrolyte of 1.2 M LiFSI in ethylene carbonate (EC) and ethyl methyl carbonate (EMC) mixed solvents. The electrochemical results shows that the corrosion current of aluminum is enhanced by cycling time and potential, which is correlated with the surface species and morphology. The formation of AlF