一种由大豆荚制备的氮硫共掺杂炭材料用于钠离子电池负极OA

Hard carbon(HC)is a promising anode material for sodium-ion batteries(SIBs)because of its large interlayer spa-cing and structural stability.However,it has a low initial Cou-lombic efficiency(ICE)and poor reversible specific capacity which limit its use.We report the use of biomass soybean pods as the precursor of a nitrogen and sulfur co-doped hard carbon with abundant mesopores,fabricated by a simple,low-cost and sustainable approach.When used as the anode for sodium-ion batteries,the relatively high nitrogen doping(～17%,mass frac-tion),ultra-low specific surface area(9.6 m2 g-1),and the large amount of pyridinic-N coordination combine to give an excellent electrochemical performance.The material has an outstand-ing electrochemical performance with a specific capacity of 425.0 mAh g-1,and an ICE of 83.7%at a current density of 0.1 A g-1.The capacity retention rate is as high as 99.5%after 110 cycles within a wide current range of 0.05-1 A g-1.An as-sembled full cell has an excellent cycling stability with 97.3%capacity retention after 100 cycles at a current density of 0.2 A g-1,and the energy density can reach as high as 141.2 Wh kg-1 at 1 A g-1.