Zhou Qiqi, Liu Junhao, Gong Xuzhong, Wang Zhi
Key Laboratory of Green Process and Engineering, National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology, Institute of Process Engineering, Chinese Academy of Sciences Beijing 100190 P. R. China
Innovation Academy for Green Manufacture, Chinese Academy of Sciences Beijing 100190 P. R. China
Nanoscale Adv. 2021 Feb 19;3(8):2287-2294. doi: 10.1039/d1na00012h. eCollection 2021 Apr 20.
To improve the inevitable capacity fading issues faced by traditional submicron Si@C electrodes used as anode materials in LIBs, a flexible and conductive connection design is proposed and realized by a solid-state growth approach. In this construction, Si@C is entangled into synthesized carbon nanotube-based network to form a highly connective Si@C/CNTs composite. The interwoven carbon-nanotubes having tight linkages with Si@C contribute to ensure the charge transfer pathway within Si@C particles and accommodate the volume expansion during cycling. The Co/N co-doping further facilitates the transportation of Li ions. As expected, the Si@C/CNT electrode shows improved conductivity and long-term cyclic stability with a high-capacity retention ratio of 80.7% after 500 cycles at 0.5 A g. In this study, the flexible and conductive connection design realized by the synthesis of CNTs can provide some reference to the improvement of alloy-type anode materials and not just Si-based anode materials for LIBs.
为改善传统亚微米硅碳复合电极作为锂离子电池负极材料时不可避免的容量衰减问题，通过固态生长法提出并实现了一种柔性导电连接设计。在这种结构中，硅碳复合物缠结到合成的碳纳米管基网络中，形成高度连接的硅碳/碳纳米管复合材料。与硅碳紧密相连的交织碳纳米管有助于确保硅碳颗粒内的电荷转移路径，并适应循环过程中的体积膨胀。钴/氮共掺杂进一步促进了锂离子的传输。正如预期的那样，硅碳/碳纳米管电极表现出改善的导电性和长期循环稳定性，在0.5 A g的电流密度下循环500次后，容量保持率高达80.7%。在本研究中，通过碳纳米管合成实现的柔性导电连接设计可为改善合金型负极材料提供一些参考，而不仅仅是用于锂离子电池的硅基负极材料。
