摘要
金属硫化物因其高理论容量在锂离子电池领域受到广泛关注,但其低导电性和在循环过程中的显著体积变化限制了其实际应用。结合缺陷工程和异质结构,提出了一种提升金属硫化物负极材料电化学性能的有效策略。首先通过合成含硫空位缺陷的BiCoS_(3-δ)纤维,不仅提供了更多的反应活性位点,还有效提升了材料的导电性。随后,在BiCoS_(3-δ)纤维上原位生长Co_(1-x)S,制备出具有异质结构的BiCoS_(3-δ)@Co_(1-x)S复合纤维,该BiCoS_(3-δ)@Co_(1-x)S异质结能够借助内建电场效应,显著促进电荷转移,增强了表面反应动力学,还能够利用异质界面的紧密接触增强纤维在充放电循环过程中的结构稳定性。因而,BiCoS_(3-δ)@Co_(1-x)S异质结构纤维展现出优异的电化学性能。尤其是在1.0 A/g电流密度下经过3000次循环后,BiCoS_(3-δ)@Co_(1-x)S电极仍保持高达413.5 mAh/g的容量,表现出了良好的循环稳定性。
Metal sulfides(MSs)have been extensively studied in lithium-ion batteries owing to their high theoretical capacity.However,their broad utilization is severely hindered by their poor conductivity and large volumetric change during cycling.One strategy for enhancing the electrochemical performance of MSs anode materials is proposed here,based on the defect engineering and heterostructure design.BiCoS_(3-δ)fibers with sulfur vacancy defects are firstly synthesized,which can not only provide more reaction active sites,but also enhance the electrical conductivity.BiCoS_(3-δ)@Co_(1-x)S composite fibers with heterostructure are also prepared by the in-situ growth of Co_(1-x)S on BiCoS_(3-δ)fibers.The heterojunction formed within BiCoS_(3-δ)@Co_(1-x)S can favor the charge transfer and enhance the surface reaction kinetics due to the build-in electric field effect.Simultaneously,the tightly contacted interface would improve their structural stability during cycle.Therefore,the heterostructured BiCoS_(3-δ)@Co_(1-x)S fibers have the best electrochemical performance.Especially,the BiCoS_(3-δ)@Co_(1-x)S electrode maintains a high capacity of 413.5 mAh/g even after 3000 cycles at 1.0 A/g,displaying the excellent cycling stability.
作者
杨豪苗
刘乐浩
马峻峰
吴卓恒
张乔木
YANG Haomiao;LIU Lehao;MA Junfeng;WU Zhuoheng;ZHANG Qiaomu(School of New Energy,North China Electric Power University,Beijing 102200,China)
出处
《功能材料》
CAS
CSCD
北大核心
2024年第12期12217-12223,共7页
Journal of Functional Materials
基金
国家自然科学基金项目(52272200)
河北省自然科学基金项目(E2022502022)。
关键词
异质结构
缺陷
纤维
负极
锂离子电池
heterostructure
defect
fiber
anode
lithium-ion battery
作者简介
通讯作者:刘乐浩,E-mail:lehaoliu@ncepu.edu.cn;杨豪苗(1996-),男,在读博士,师承马峻峰教授,从事锂离子电池负极材料研究。
