Graphene‐Armored Aluminum Foil with Enhanced Anticorrosion Performance as Current Collectors for Lithium‐Ion Battery

Abstract Aluminum (Al) foil, as the most accepted cathode current collector for lithium‐ion batteries (LIBs), is susceptible to local anodic corrosions during long‐term operations. Such corrosions could lead to the deterioration or even premature failure of the batteries and are generally believed to be a bottleneck for next‐generation 5 V LIBs. Here, it is demonstrated that Al foil armored by conformal graphene coating exhibits significantly reinforced anodic corrosion resistance in both LiPF 6 and lithium bis(trifluoromethanesulphonyl) imide (LiTFSI) based electrolytes. Moreover, LiMn 2 O 4 cells using graphene‐armored Al foil as current collectors (LMO/GA) demonstrate enhanced electrochemical performance in comparison with those using pristine Al foil (LMO/PA). The long‐term discharge capacity retention of LMO/GA cell after ≈950 h straight operations at low rate (0.5 C) reaches up to 91%, remarkably superior to LMO/PA cell (75%). The self‐discharge propensity of LMO/GA is clearly relieved and the rate/power performance is also improved with graphene mediations. This work not only contributes to the long‐term stable operations of LIBs but also might catalyze the deployment of 5 V LIBs in the future.