蜂窝状多孔碳材料装载硫单质及其在锂硫电池中的储能性能研究  

Study of Sulfur Loaded in Honeycomb-Like Porous Carbon Materials and Energy Storage Performance in Lithium-Sulfur Battery

作　　者：康小雅 何天启 朱福良 冉奋 KANG Xiaoya;HE Tianqi;ZHU Fuliang;RAN Fen(State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals,School of Materials Science&Engineering,Lanzhou University of Technology,Lanzhou 730050,China)

机构地区：[1]兰州理工大学材料科学与工程学院,省部共建有色金属先进加工与再利用国家重点实验室,兰州730050

出　　处：《材料导报》2024年第16期6-11,共6页Materials Reports

基　　金：国家自然科学基金(51763014,52073133);甘肃省重点人才项目。

摘　　要：单质硫及其放电最终产物Li_(2)S的绝缘性以及两者密度差异引起的结构坍塌等问题严重阻碍了锂硫电池的进一步发展,找寻合适的基体材料是解决上述问题的有效策略。本工作选用一种蜂窝状多孔碳作为硫正极的基体材料,通过常规的熔融扩散法将硫单质固定在碳孔隙中,并利用SEM、XRD、XPS和BET等方法对多孔碳@单质硫复合材料进行了表征。结果表明,硫单质均匀地负载在碳骨架中。同时,蜂窝状结构碳不仅为硫单质提供了电子导电网络,也保证了正极的稳定性。更重要的是,蜂窝状的结构为循环过程中硫正极的体积膨胀提供了一定的缓冲空间,缓解了结构坍塌这一问题。此外,碳基体丰富的孔隙度在一定程度上减少了多硫化物的穿梭。因此,在0.1C的倍率下,多孔碳@单质硫复合材料首次放电比容量高达1125.9 mAh/g,300次循环后比容量可保持305.1 mAh/g。The further development of lithium sulfur battery is severely hindered by the insulation of elemental sulfur and its final product Li_(2)S as well as the structural collapse caused by their density difference,so finding a suitable carrier material is an efficient strategy to address the above-mentioned problems.In this work,a honeycomb-like porous carbon is selected as the host material for the sulfur cathode,the sulfur is immobilized in the pores of porous carbon by conventional melt diffusion method,and porous carbon@sulfur composite is characterized by SEM,XRD,XPS and BET techniques.The results show that the sulfur was uniformly loaded in the carbon skeleton.Meanwhile,the high electrical conductivity and honeycomb-like structure of porous carbon not only provide an electronic conductive network for the sulfur,but also ensures the stability of the cathode.More importantly,the honeycomb structure gives some buffer space for the volume expansion of the sulfur cathode during the cycling process,which lessens the trouble of structural collapse.In addition,the abundant pores in the host material decrease the shuttling of polysulfides to some extent.Therefore,the specific capacity of porous carbon@sulfur composite can deliver 1125.9 mAh/g at 0.1C during the first discharging and maintain 305.1 mAh/g after 300 cycles.

关 键 词：锂硫电池 正极材料 蜂窝状多孔碳 电化学性能 

分 类 号：O646.21[理学—物理化学]