硫化钒/石墨烯基锂硫电池正极材料电化学性能研究  

The Study on the Electrochemical Performance of Lithium-Sulfur Battery Cathode Based on Vanadium Sulfide/Reduced Graphene Oxide

作　　者：贾蓓蓓 朱基亮[1] 

机构地区：[1]四川大学材料科学与工程学院,四川 成都

出　　处：《材料科学》2022年第4期352-361,共10页Material Sciences

摘　　要：为缓解锂硫电池放电过程中多硫化锂的穿梭效应,提高电池整体电化学性能,本文采用水热法合成了硫化钒/还原氧化石墨烯(VS4/rGO)作为正极中的硫载体材料和有效吸附组分,载硫后实现了对硫颗粒的柔性包裹,硫含量为73.9 wt%,并对材料的形貌和特性进行了分析研究。对制备的锂硫电池正极(VS4/rGO@S8-C)进行电化学测试,结果表明在0.2 C的电流密度下,该正极的首圈放电比容量为1139.2 mAh∙g−1,远高于CB@S8-C正极(565.2 mAh∙g−1),VS4/rGO@S8-C正极循环100圈后的容量保持率为75.6%。在5 mg∙cm−2的高硫面负载量和0.5 C的高电流密度下,VS4/rGO@S8-C正极的首圈容量为609.4 mAh∙g−1,循环100圈后的容量保持率为66.3%,具有良好的循环稳定性。In order to alleviate the shuttle effect of lithium polysulfides during the discharge process and improve the electrochemical performance of lithium-sulfur batteries, vanadium sulfide/reduced graphene oxide (VS4/rGO), as the sulfur host and adsorption component in the cathode, was synthesized by hydrothermal method. After sulfur loading, the flexible encapsulation for sulfur particles as well as a high sulfur content of 73.9 wt% was realized. The morphology and characteristics of the cathode materials were analyzed and VS4/rGO@S8-C cathode was tested by several electrochemical tests. The results show that the cathode has a high initial specific capacity of 1139.2 mAh∙g−1 at 0.2 C with the retention of 75.6%, which is much higher than CB@S8-C cathode (565.2 mAh∙g−1). Moreover, even at a high sulfur loading of 5 mg•cm−2 and a high current density of 0.5 C, the initial capacity of VS4/rGO@S8-C cathode is 609.4 mAh∙g−1, and the retention rate after 100 cycles was 66.3%, indicating the good cycle stability.

关 键 词：硫化钒 石墨烯 锂硫电池正极 

分 类 号：TB33[一般工业技术—材料科学与工程] TM912[电气工程—电力电子与电力传动]