Controllable synthesis of hierarchical core-shell NiS2/CoS2@N,S-C nanospheres for lithium storage
Controllable synthesis of hierarchical core-shell NiS2/CoS2@N,S-C nanospheres for lithium storage
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DOI：
10.1016/j.jallcom.2022.165112
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发表时间：
2022-04
影响因子：
6.2
通讯作者：
Xinrong Cao;Weixing Min;Ping Chen;Dongwei Xu;Dong Liu;Ruiqi Wang
中科院分区：
文献类型：
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作者：
Xinrong Cao;Weixing Min;Ping Chen;Dongwei Xu;Dong Liu;Ruiqi Wang
过渡金属硫化物（TMS）作为锂离子电池负极材料具有较高的理论容量，TMS的结构设计是获得良好电化学性能的有效策略。本文制备了由NiS 2/CoS 2基体和N，S-共掺杂碳外层（N，S-C）组成的分级NiS 2/CoS2@N，S-C纳米球。此外，当精确控制镍和钴的量时，在本研究中出现了具有不同核-壳结构的NiS 2/CoS2@N，S-C纳米球，这进一步证实了镍和钴在剪裁和调节结构方面的不同能力。特别是NiS 2/CoS2@N，S-C（Ni：Co=1：2）具有蛋黄壳结构，内部存在足够的空穴空间，有利于Li+和电子的传输，同时，N，S-共掺杂碳层和多孔片阵列的保护作用增强了结构稳定性，增加了活性中心。得益于独特的结构，具有二元金属硫化物组成的NiS 2/CoS2@N，S-C（Ni：Co=1：2）阳极具有良好的循环性能（在0.2 A g− 1下100次循环后为795 mAh g− 1）和倍率性能（在5 A g−1下为469 mAh g−1）。该研究为在储能领域设计和制备不同形貌的新型TMS基材料提供了参考。
Transition metal sulfides (TMSs) present high theoretical capacity as anode materials for Lithium-ion batteries, and structural design of TMSs is proved to be an effective strategy to acquire satisfactory electrochemical performances. Herein, the hierarchical NiS2/CoS2@N,S-C nanospheres consisting of NiS2/CoS2matrixes and N,S-codoped carbon outer layer (N,S-C) are fabricated. Additionally, NiS2/CoS2@N,S-C nanospheres with different core-shell structures appear in this study when the amount of nickle and cobalt is precisely controlled, which further confirms the different abilities of nickle and cobalt in tailoring and modulating structure. In particular, the NiS2/CoS2@N,S-C(Ni:Co=1:2) with yolk-shell property presents sufficient internal void space, which is conductive to the transport of Li+and electron. Moreover, the protective N,S-codoped carbon layer and the porous sheet arrays provide the enhanced structural stability and increased active sites. Benefitting from the unique structure, the NiS2/CoS2@N,S-C(Ni:Co=1:2) anode with binary metal sulfide composition presents good cycling performance (795 mAh g−1at 0.2 A g−1after 100 cycles) and rate capability (469 mAh g−1at 5 A g−1). This study provides a reference for the design and preparation of novel TMSs-based materials with different morphologies in the field of energy storage.