Sun Qing, Li Deping, Dai Linna, Liang Zhen, Ci Lijie
Research Center for Carbon Nanomaterials, Key Laboratory for Liquid-Solid Structural Evolution & Processing of Materials (Ministry of Education), School of Materials Science and Engineering, Shandong University, Jinan, 250061, China.
School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055, China.
Small. 2020 Nov;16(45):e2005023. doi: 10.1002/smll.202005023. Epub 2020 Oct 20.
Conversion-alloying type anode materials like metal sulfides draw great attention due to their considerable theoretical capacity for sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs). However, poor conductivity, severe volume change, and harmful aggregation of the material during charge/discharge lead to unsatisfying electrochemical performance. Herein, a facile and green strategy for yolk-shell structure based on the principle of metal evaporation is proposed. SnS nanoparticle is encapsulated in nitrogen-doped hollow carbon nanobox (SnS @C). The carbon nanoboxes accommodate the volume change and aggregation of SnS during cycling, and form 3D continuous conductive carbon matrix by close contact. The well-designed structure benefits greatly in conductivity and structural stability of the material. As expected, SnS @C exhibits considerable capacity, superior cycling stability, and excellent rate capability in both SIBs and PIBs. Additionally, in situ Raman technology is unprecedentedly conducted to investigate the phase evolution of polysulfides. This work provides an avenue for facilely constructing stable and high-capacity metal dichalcogenide based anodes materials with optimized structure engineering. The proposed in-depth electrochemical measurements coupled with in situ and ex situ characterizations will provide fundamental understandings for the storage mechanism of metal dichalcogenides.
像金属硫化物这样的转化合金型负极材料因其在钠离子电池（SIBs）和钾离子电池（PIBs）中具有可观的理论容量而备受关注。然而，导电性差、严重的体积变化以及材料在充放电过程中的有害团聚导致电化学性能不尽人意。在此，基于金属蒸发原理提出了一种简便且绿色的制备蛋黄壳结构的策略。将硫化锡纳米颗粒封装在氮掺杂的中空碳纳米盒（SnS@C）中。碳纳米盒在循环过程中容纳硫化锡的体积变化和团聚，并通过紧密接触形成三维连续导电碳基体。精心设计的结构极大地有利于材料的导电性和结构稳定性。正如预期的那样，SnS@C在SIBs和PIBs中均表现出可观的容量、优异的循环稳定性和出色的倍率性能。此外，前所未有的原位拉曼技术被用于研究多硫化物的相演变。这项工作为通过优化结构工程简便地构建稳定且高容量的基于金属二硫属化物的负极材料提供了一条途径。所提出的深入电化学测量以及原位和非原位表征将为金属二硫属化物的存储机制提供基本认识。
