Nitrogen/fluorine dual-doped resin-based hard carbon anode with high capacity retention for lithium storage

Heteroatom doping of carbon materials can effectively alter the microstructure and conductivity, thereby improving the electrochemical performance of lithium-ion batteries (LIBs) hard carbon anodes. Herein, a resin-based hard carbon material (NFHC-1200) with co-doped N and F was prepared by one-step pyrolysis method using phenolic resin as the carbon source and ammonium fluoride as the doped N and F sources. Benefiting from the synergistic effects of co-doping, NFHC-1200 exhibited a wider interlayer distance (0.385 nm), a larger specific surface area (93.31 m2 g−1), and a greater number of Li+ storage active sites (ID/IG = 1.754) when compared to undoped HC-1200 and single-atom doped NHC-1200 hard carbon materials. The results of electrochemical performance demonstrated that the electrochemical properties of NFHC-1200 was significantly improved for co-doped N and F. It exhibited an initial discharge capacity of 614.6 mAh g−1 at 37.2 mA g−1, a reversible capacity of 365.2 mAh g−1 with a capacity retention rate of 97.66