Unveiling the passivation and corrosion process of cathode aluminum current collector in lithium-ion battery

To ensure reliable deployment of stable high-voltage LIBs, investigating the corrosion behavior and underlying mechanism of the Al current collector is imperative. This research on Al corrosion in LiPF₆ electrolyte indicates that the stability of the passivation layer (AlF₃/Al₂O₃) is significantly affected by the operating voltage. The corrosion resistance, R_pit, displays a nonlinear distribution with a peak at 4 V, and pitting occurs beyond 4 V. The heterogeneous and wrinkled AlF₃ layer triggers localized breakdown. The established model of pitting initiation and expansion is supported by morphological evolution, quantitative component analysis, and electrochemical test results.