Three-dimensional laser-induced holey graphene and its dry release transfer onto Cu foil for high-rate energy storage in lithium-ion batteries

Next-generation batteries require high-rate energy storage capabilities owing to the advent of fast charging electrical applications. Energy storage materials that can regulate the capacity even at high current densities must be developed. However, this is challenging owing to the limited ion transport kinetics inherent in thick electrodes. The sluggish ion transport can be mitigated by adopting nanomaterials with high specific surface areas or fabricating electrodes with structural alignment. Nevertheless, the rearrangement of materials in electrodes that facilitate fast charging with external forces and additives does not provide a satisfactory ion transport rate. In this study, for realizing a high-rate anode material, facet-controlled three-dimensional holey graphene is fabricated by transferring laser-induced graphene (LIG) to a copper tape in dry condition. This electrode exhibits a consistent capacity of similar to 114 mAh g(-1) at an increased mass loading of 3 mg cm(-2) and a high current density of 20 A g(-1), implying that 95% capacity can be charged within 3 min. This exceptionally high rate is attributed to the unique structure of the transferred LIG (three dimensionally aligned macro/meso-porous LIG flakes featuring preferential surface facet directions). This fabrication is compatible with the existing manufacturing process for anode materials and can be applied to other energy materials.