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

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 AlCl4- ions, graphene-based cathodes have specific capacities of approximate to 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 degrees 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 approximate to 3000 degrees 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.

Automated summary

The article introduces a thermal reductive perforation (TRP) strategy to convert three-layer graphene nanosheets into surface-perforated graphene materials, which exhibit good reversible capacity and high energy density in aluminum-ion batteries.