Graphene Enables Aluminum Current Collectors of 5 V Class Battery

The five volt-class battery is one promising candidate of high energy density lithium-ion batteries. However, it suffers from limited electrochemical performance due to many problems, one of which is Al current collector corrosion. The corrosion greatly affects the electrochemical performance of batteries, so uncovering the Al corrosion mechanism and developing its protection strategy in the 5 V-class battery becomes important. Here, we experimentally realize a corrosion-resistant Al current collector via graphene protection. The experimental and theoretical calculation indicate that graphene can work as a physical barrier to inhibit direct contact between LiPF₆-based electrolyte and an Al current collector, reducing the side reactions between Al current collector and HF originated from electrolyte. What is more, graphene increases the Al corrosion reaction potential, raising the difficulty of electrochemical corrosion. These effects improve the electrochemical performance of the 5 V-class battery, especially the rate performance and cycling stability. The work is beneficial for the development of a 5 V-class battery.