Tuning dual three-dimensional porous copper/graphite composite to achieve diversified utilization of copper current collector for lithium storage

Graphite anode materials are widely used in commercial lithium-ion batteries; however, the long electron/ion transportation path restricted its high energy storage. In this experiment, we designed a copper/graphite composite with a dual three-dimensional (3D) continuous porous structure combining used nonsolvent-induced phase separation and heat treatment, in which a large amount of graphite is embedded in the 3D porous copper/carbon architecture. In the novel structure, not only the electron and Li+ transmission performances are improved, but also the space of current collector is fully utilized. Meanwhile, carbonized polyacrylonitrile network stabilizes the interface between graphite and copper matrix. The obtained copper/graphite composite anode has an initial discharge capacity of 524.6 mAh·g−1, a holding capacity of 350 mAh·g−1 and excellent cycle stability (299.3 mAh·g−1 after 180 cycles at 0.1C rate), exhibiting good electrochemical performance. The experimental results show that the mass loading of the copper/graphite composite electrode material is about 4.39 mg·cm−2. We also envisage replacing graphite with other high-capacity active materials to fill the current collector, which can provide a reference for the future development of next-generation advanced electrodes.