Sun Lin, Wang Xin, Liu Yang, Xu Hongnan, Wang Hongyu, Lu Yuyan, Jin Zhong
Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province, School of Chemistry and Chemical Engineering, Yancheng Institute of Technology, Yancheng 224051, China.
State Key Laboratory of Coordination Chemistry, MOE Key Laboratory of Mesoscopic Chemistry, MOE Key Laboratory of High Performance Polymer Materials and Technology, Jiangsu Key Laboratory of Advanced Organic Materials, Tianchang New Materials and Energy Technology Research Center, Institute of Green Chemistry and Engineering, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.
ACS Appl Mater Interfaces. 2024 Oct 2;16(39):52349-52357. doi: 10.1021/acsami.4c10691. Epub 2024 Sep 19.
Porous silicon (pSi) is considered a promising candidate for next-generation high-energy-density lithium-ion battery (LIB) anodes due to its ability to mitigate volume expansion stress. However, the lack of efficient preparation methods and severe side reactions due to its large specific surface area have hindered its commercial development. This study leverages the redox reaction between the Zintl compound MgSi and SiO at certain temperatures, using intermediate products as templates, and incorporates CVD deposition to create carbon-coated porous silicon (pSi@C) composite anode materials with excellent electrochemical performance. This approach enables pSi to achieve a high specific capacity, high rate performance, and long lifetime. Additionally, a prelithiation process effectively addresses the issue of low initial Coulombic efficiency (ICE) in pSi electrodes. In half-cell tests, the pSi@C electrode delivered a reversible specific capacity as high as 1500 mAh g and outstanding rate performance (over 500 mAh g at a high current density of 5 A g). After repeated charge/discharge 1000 times at 1 A g, the reversible capacity remained at 555 mAh g. Full-battery assembly with NCM811 cathodes also demonstrated the potential of pSi@C as a promising anode candidate. This work aims to expand the preparation methods for pSi materials and provide guidance for their application in high-energy-density LIBs.
多孔硅（pSi）因其能够缓解体积膨胀应力，被认为是下一代高能量密度锂离子电池（LIB）负极的一个有前景的候选材料。然而，缺乏有效的制备方法以及因其大比表面积导致的严重副反应阻碍了其商业发展。本研究利用在特定温度下Zintl化合物MgSi与SiO之间的氧化还原反应，以中间产物为模板，并结合化学气相沉积法来制备具有优异电化学性能的碳包覆多孔硅（pSi@C）复合负极材料。这种方法使pSi能够实现高比容量、高倍率性能和长寿命。此外，预锂化过程有效地解决了pSi电极中初始库仑效率（ICE）低的问题。在半电池测试中，pSi@C电极提供了高达1500 mAh g的可逆比容量和出色的倍率性能（在5 A g的高电流密度下超过500 mAh g）。在1 A g下重复充放电1000次后，可逆容量保持在555 mAh g。与NCM811正极组装的全电池也证明了pSi@C作为有前景的负极候选材料的潜力。这项工作旨在拓展pSi材料的制备方法，并为其在高能量密度LIBs中的应用提供指导。
