文摘
A nanoporous N-doped reduced graphene oxide (p-N-rGO) was prepared through carbothermal reaction between graphene oxide and ammonium-containing oxometalates as sulfur host for Li–S batteries. The p-N-rGO sheets have abundant nanopores with diameters of 10–40 nm and the nitrogen content is 2.65 at%. When used as sulfur cathode, the obtained p-N-rGO/S composite has a high reversible capacity of 1110 mAh g−1 at 1C rate and stable cycling performance with 781.8 mAh g−1 retained after 110 cycles, much better than those of the rGO/S composite. The enhanced electrochemical performance is ascribed to the rational combination of nanopores and N-doping, which provide efficient contact and wetting with the electrolyte, accommodate volume expansion and immobilize polysulfides during cycling.