摘要
开发优异储锂/储钠性能的新型负极材料对现有电池系统的发展至关重要.因其高的理论容量,多组分金属硫化物被认为是有潜力的锂/钠离子电池负极材料.然而,合成工艺的简化和金属硫化物间异质界面的构建仍然面临巨大挑战.本文通过一锅水热法,以一维的钴/次氮基三乙酸配位聚合物纳米纤维为前驱体,构建了一种1T-MoS2/碳纳米片修饰的含Co1–xS纳米颗粒的氮掺杂多层中空碳纤维(Co1–xS/NC@MoS2/C). Co1–xS/NC中空纤维的形成与MoS2的生长同时进行;MoS2纳米片修饰的中空纤维可提供丰富的活性表面并缩短离子扩散路径,有利于电子传输和锂/钠离子扩散;同时, MoS2和Co1–xS周围形成的碳基体,不仅有利于结构的完整性和导电性,而且避免了活性物质与电解质的直接接触. Co1–xS/NC@MoS2/C作为锂/钠离子电池负极材料,展现出优异的倍率性能和循环寿命.本文为多维异质纳米复合材料的构建提供了潜在的方法.
Multicomponent metal sulfides have been recognized as promising anode materials for lithium/sodiumion storage given their enticing theoretical capacities. However, the simplification of synthetic processes and the construction of heterogeneous interfaces of multimetal sulfides remain great challenges. Herein,a hierarchical 1T-MoS2/carbon nanosheet decorated Co1–xS/N-doped carbon(Co1–xS/NC@MoS2/C) hollow nanofiber was designed and constructed via a one-pot hydrothermal method using a cobalt-based coordination polymer nanofiber. This nanofiber can transform in-situ into conductive N-doped carbon hollow fibers embedded with active Co1–xS nanoparticles, enabling the epitaxial growth of MoS2 nanosheets.Consequently, the Co1–xS/NC@MoS2/C composites achieve exceptional lithium/sodium-ion storage performance. Compared to MoS2/C microspheres and Co1–xS/NC hollow nanofibers alone, the Co1–xS/NC@MoS2/C hollow nanofibers deliver higher discharge capacities(1085.9 mAh g^-1 for lithium-ion batteries(LIBs) and 748.5 mAh g^-1 for sodium-ion batteries(SIBs) at 100 mA g^-1), better capacity retention(910 mAh g^-1 for LIBs and 636.5 mAh g^-1 for SIBs after 150 cycles at 100 mA g^-1), and increased cycling stability(407.2 mAh g^-1 after 1000 cycles for SIBs at 1000 m A g^-1). Furthermore, the kinetic analysis shows that the lithium/sodium-ion storage processes of the Co1–xS/NC@MoS2/C electrode are mainly controlled by pseudocapacitance behavior. The excellent electrochemical properties can thus be ascribed to the synergy of the MoS2/C nanosheets with the enlarged interlayer spacing, good conductivity of the carbon layers, and the Co1–xS nanoparticles embedded in the hollow nanofibers with extensive reaction sites.
作者
王燕子
谢婉仪
李冬至
韩沛
石逯迪
罗远益
从广涛
李翠华
于佳立
朱才镇
徐坚
Yanzi Wang;Wanyi Xie;Dongzhi Li;Pei Han;Ludi Shi;Yuanyi Luo;Guangtao Cong;Cuihua Li;Jiali Yu;Caizhen Zhu;Jian Xu(Institute of Low-dimensional Materials Genome Initiative,College of Chemistry and Environmental Engineering of Shenzhen University,Shenzhen 518060,China)
基金
This work was supported by the National Natural Science Foundation of China(51673117,21805193 and 51973118)
Postdoctoral Science Foundation of China(2019M650212)
Key R&D Program of Guangdong Province(2019B010929002 and 2019B010941001)
Science and Technology Innovation Commission of Shenzhen(JCYJ20170817094628397,JCYJ20170818093832350,JCYJ20170818112409808,JCYJ20170818100112531,JCYJ20180507184711069,and JCYJ20180305125319991)
The authors also thank the Materials and Devices Testing Center of Tsinghua University Shenzhen Graduate School.