Ultra-fast and ultra-long-life Li ion batteries with 3D surface-porous graphene anodes synthesized from CO2†
The Li-ion batteries (LIBs) with ultra-fast charge/discharge behavior and long-term cyclic performance are highly desirable for many applications. Herein, the three-dimensional graphene (3DG) with rich surface-pores, which was synthesized directly from Na-reduction of CO2, was demonstrated as an efficient anode for LIBs. The 3DG anode exhibited a very high discharge capacity of 972 mA h g−1 at 0.2C and an outstanding reversible capacity of 277 mA h g−1 at an extremely high current density of 150C (55.8 A g−1). Furthermore, a discharge capacity of 280 mA h g−1 was obtained after 10 000 cycles at 50C, reaching a high capacity retention of 91.9%. Such an excellent electrochemical performance was attributed to the large specific surface area of 3DG and its rich surface-micropores as well as its numerous oxygen-induced defects. This provides a new door to develop highly efficient electrodes from a greenhouse gas for long-life and ultrafast-charging LIBs.