A novel one-step method to prepare N, S Co-doped sub-fluorinated carbon electrode materials for ultrahigh-rate lithium-fluorinated carbon battery

To improve the electrochemical performance of fluorinated carbon (CF x ) for lithium-fluorinated carbon batteries , the nitrogen and sulfur co-doped sub-fluorinated carbon cathode material (NS-sCF x ) is synthesized by a one-step method of heteroatom doping and defluorination . Experimental results confirm that nitrogen and sulfur elements are successfully doped on the surface of CF x material, and the surface fluorinated degree is reduced. DFT calculations and experimental results demonstrate that the heteroatoms co-doping and defluorination can generate a conductive interface, increase activation sites, and induce charge redistribution, producing a superior transfer rate of electrons and lithium ions . Hence, the NS-sCF x cathode material possesses excellent electrochemical properties , large specific capacity, high-rate performance, high power density, and no initial voltage delay. The Li/NS-sCF x battery delivers a specific capacity of 590.4 mAh·g −1 with a voltage plateau of 1.997 V at 20 C without initial voltage delay, corresponding to a power density is 35946 W kg −1 . Extraordinarily, an ultra-high power density of up to 107100 W kg −1 at 70 C is achieved without significantly initial voltage delay. This study reveals the functional mechanism of NS-co-doping and defluorination to improve the electrochemical performance of NS-sCF x material, which can be used as a reference for the design and development of related electrode materials .