Thermal Reductive Perforation of Graphene Cathode for High‐Performance Aluminum‐Ion Batteries

Abstract Controlling the structure of graphene‐based materials with improved ion intercalation and diffusivity is crucial for their applications, such as in aluminum‐ion batteries (AIBs). Due to the large size of AlCl 4 − ions, graphene‐based cathodes have specific capacities of ≈60 to 148 mAh g −1 , limiting the development of AIBs. A thermal reductive perforation (TRP) strategy is presented, which converts three‐layer graphene nanosheets to surface‐perforated graphene materials under mild temperature (400 °C). The thermal decomposition of block copolymers used in the TRP process generates active radicals to deplete oxygen and create graphene fragments. The resultant material has a three‐layer feature, in‐plane nanopores, >50% expanded interlayer spacing, and a low oxygen content comparable to graphene annealed at a high temperature of ≈3000 °C. When applied as an AIB cathode, it delivers a reversible capacity of 197 mAh g −1 at a current density of 2 A g −1 and reaches 92.5% of the theoretical capacity predicted by density‐functional theory simulations.