双金属掺杂多孔碳正极材料的合成与电化学性能  

Synthesis and electrochemical properties of bimetallic-doped porous carbon cathode material

作　　者：曹翔宇[1] 张嘉盈 丰赟 申林坤 张秀玲 闫娟枝[1] CAO Xiangyu;ZHANG Jiaying;FENG Yun;SHEN Linkun;ZHANG Xiuling;YAN Juanzhi(Department of Materials and Chemical Engineering,Taiyuan University,Taiyuan 030032,China)

机构地区：[1]太原学院材料与化学工程系,太原030032

出　　处：《无机化学学报》2025年第3期509-520,共12页Chinese Journal of Inorganic Chemistry

基　　金：山西省基础研究计划项目(No.202103021223003);国家级大学生创新创业训练项目(No.20241387);省级大学生创新创业训练项目(No.20241437)资助。

摘　　要：利用水热反应制备了葡萄糖缩聚物包覆铁氰化钴晶体的复合前驱体,经过碳化、酸刻蚀和硫负载,最终获得一种双金属(Co、Fe)及氮掺杂的多孔碳/硫复合材料(e-CF@NPC/S,其中CF表示CoFe合金,NPC表示氮掺杂的多孔碳)。进而通过改变形成核壳的原料比例获得系列样品,研究其作为锂硫电池正极的电化学性能。结果表明:该材料的核壳结构提供了充足的空间应对电池反应过程中的活性物质负载及体积变化,碳外壳的空间位阻同时起到了抑制穿梭效应的积极作用和阻碍离子扩散的负面作用,而合金纳米粒子提供吸附和催化作用的效果取决于其表面活性位点的数量。在多种作用的协同下,e-CF@NPC-3/S表现出优异的综合电化学性能,在0.2C的电流密度下循环100次后能保持996.9 mAh·g^(-1)的可逆比容量和92.35%的容量保持率。在1C的高电流密度下循环300次后,e-CF@NPC-3/S仍具有684.5 mAh·g^(-1)的可逆比容量(循环衰减率为0.049%)。A bimetallic(Co,Fe)and nitrogen-doped porous carbon/sulfur composite material(e-CF@NPC/S,CF represents CoFe alloy,NPC represents nitrogen-doped porous carbon)was prepared by hydro-thermal reaction,carbonization,acid etching,and S loading.Then a series of composite materials with different nuclear shell ratios were obtained by changing the ratio of raw materials.The structural analysis and electrochemical properties test results of these composite materials show that core-shell structure porous carbon composite had a rich surface area and space to serve active substance loading and volume changes.The spatial domain restriction of the shell can be helpful to anchor sulfur and polysulfide(LiPSs)inside the structure,however,the shell can also block ion diffusion.The catalytic and absorptive capability of Co-Fe alloy depends on the quantities of active sites.Cathodes of e-CF@NPC-3/S show the best electrochemistry performance with a capacity retention rate of 92.35%at 0.2C after 100 cycles(initial capacity was 996.9 mAh·g^(-1)).After 300 cycles at 1C,it can achieve a capacity decay rate of 0.049%per cycle(initial capacity was 684.5 mAh·g^(-1)).

关 键 词：金属掺杂 锂硫电池 正极材料 复合材料 核壳结构 

分 类 号：TM911[电气工程—电力电子与电力传动]