Peng Hui, Miao Wenxing, Cui Shuzhen, Liu Zhiyuan, Tao Bo, Hou Wenbo, Ma Guofu, Lei Ziqiang
Key Laboratory of Eco-functional Polymer Materials of the Ministry of Education, Key Laboratory of Polymer Materials of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou, 730070, China.
Small. 2024 Nov;20(45):e2404957. doi: 10.1002/smll.202404957. Epub 2024 Jul 19.
Transition metal sulfides are investigation hotspots of anode material for sodium-ion batteries (SIBs) due to their structural diversity and high storage capacity. However, they are still plagued by inevitable volume expansion during sodiation/desodiation and an unclear energy storage mechanism. Herein, a one-step sulfidation-carbonization strategy is proposed for in situ confined growth of CuS nanoparticles in nitrogen-doped carbon (CuS@NC) using octahedral metal-organic framework (Cu-BTC) as a precursor and investigate the driving effect of Cu current collector on its sodium storage. The generation of S─C bonds in CuS@NC avoids the volume change and structural collapse of CuS nanoparticles during the cycling process and improves the adsorption and transport capacity of the material for Na. More exciting, the Cu species in the Cu current collector are self-induced forming CuS quantum dots to enter the original anode material during the initial few charging and discharging cycles, which unique small-size effect and abundant edge-active sites enhance the energy storage capacity of CuS. Thus, the CuS@NC exhibits a superior first discharge capacity of 608.56 mAh g at 0.2 A g with an initial Coulomb efficiency (ICE) of 75.4%, as well as provides excellent rate performance and long cycle durability up to 2000 cycles.
过渡金属硫化物因其结构多样性和高存储容量，成为钠离子电池（SIBs）负极材料的研究热点。然而，它们在 sodiation/desodiation 过程中仍不可避免地受到体积膨胀的困扰，且储能机制尚不明确。在此，提出了一种一步硫化 - 碳化策略，以八面体金属有机框架（Cu - BTC）为前驱体，原位限域生长氮掺杂碳包覆的 CuS 纳米颗粒（CuS@NC），并研究 Cu 集流体对其储钠性能的驱动作用。CuS@NC 中 S─C 键的生成避免了 CuS 纳米颗粒在循环过程中的体积变化和结构坍塌，提高了材料对 Na 的吸附和传输能力。更令人兴奋的是，Cu 集流体中的 Cu 物种在最初的几次充放电循环中自诱导形成 CuS 量子点并进入原始负极材料，其独特的小尺寸效应和丰富的边缘活性位点增强了 CuS 的储能能力。因此，CuS@NC 在 0.2 A g 时表现出 608.56 mAh g 的优异首次放电容量，初始库仑效率（ICE）为 75.4%，同时还具有出色的倍率性能和长达 2000 次循环的长循环耐久性。
