开发廉价、高效、稳定的钠离子电池用碳负极材料是电化学储能领域的重要研究方向之一。以针状焦为碳源,升华硫为硫源,通过机械球磨结合硫掺杂的两步工艺制备了硫掺杂针状焦基多孔碳材料(S-NC),并应用于钠离子电池的负极。SEM、TEM和XPS表征结果证实,硫掺杂策略能够有效减小碳材料的粒径,增加碳材料的层间距,同时提高碳骨架的缺陷密度。氮气吸脱附测试结果表明,相较未掺杂碳,S-NC的孔容显著提升,并富含介孔。电化学测试结果显示,当掺杂温度为600℃时,制备的硫掺杂碳(S-NC-600)表现出优异的储钠性能。在电流密度为0.05A/g时,S-NC-600的比容量为487.3mAh/g;在2A/g高电流密度下,比容量为275.5mAh/g,且经1000次循环充放电后,容量保持率为90.7%,展现出良好倍率性能和循环稳定性,可为高效钠离子电池用碳负极的制备提供理论支撑。

The development of cheap, efficient and stable carbon anode materials for sodium ion batteries is one of the important researchdirections in the field of electrochemical energy storage. Sulfur doped needle coke based polyporous carbon (S-NC) was prepared by atwo-step process of mechanical ball milling combined with sulfur doping using needle coke as carbon source and sublimed sulfur as sulfursource, and was applied to the negative electrode of sodium ion batteries. The results of SEM, TEM and XPS indicate that the sulfur doping strategy can effectively reduce the particle size of carbon materials, increase the layer spacing of carbon materials, and increase thedefect density of carbon skeleton. The results of nitrogen adsorption and desorption test show that compared with undoped carbon, the porevolume of S-NC is significantly increased, and it is rich in mesoporous. The electrochemical test results show that the prepared sulfurdoped carbon (S-NC-600) exhibits excellent sodium storage properties when the doping temperature is 600 ℃ . When the current densityis 0.05 A/ g, the specific capacity of S-NC-600 is 487.3 mAh/ g. At 2 A/ g high current density, the specific capacity is 275.5 mAh/ g,and after 1 000 cycles of charge and discharge, the capacity retention rate is 90.7%, showing good rate performance and cycle stability,which can provide theoretical support for the preparation of carbon anode for high efficiency sodium-ion batteries.

0 引言

1 试验

   1.1 S-NC的制备

   1.2 电极的制备

   1.3 S-NC的表征

2 结果与讨论

   2.1 S-NC的结构与形貌

   2.2 不同电极材料的电化学性能测试

3 结论