Vacuum-Dried 3D Holey Graphene Frameworks Enabling High Mass Loading and Fast Charge Transfer for Advanced Batteries

Monolithic 3D graphene frameworks (GFs) electrode materials have exhibited the great potential for energy storage devices. However, most approaches for fabricating 3D GF require expensive and sophisticated drying techniques, and the current achieved 3D GF electrodes usually hold a relatively low mass loadings of the active materials with low areal capacity, which is not satisfactory for practical application. Herein, a convenient, economic, and scalable drying approach is developed to fabricate 3D holey GFs (HGFs) by a vacuum-induced drying (VID) process for the first time. This binder-free 3D HGF electrode with high mass loading can obtain extraordinary electrochemical performance for lithium-ion batteries (LIBs) due to the 3D holey graphene network owning a highly interconnected hierarchical porous structure for fast charge and ion transport. The HGF electrode with high mass loading of 4mgcm(-2) exhibits superior rate performance and delivers an areal capacity as high as 5mAhcm(-2) under the current density of 8mAcm(-2) even after 2000 cycles, considerably outperforming those of state-of-the-art commercial anodes and some representative anodes in other studies. This facile drying approach and robust realization of high areal capacity represent a critical step for 3D graphene-based electrode materials toward practical electrochemical energy storage devices.