Di Fang, Gu Xin, Chu Yang, Li Lixiang, Geng Xin, Sun Chengguo, Zhou Weimin, Zhang Han, Zhao Hongwei, Tao Lin, Jiang Guangshen, Zhang Xueyuan, An Baigang
Key Laboratory of Energy Materials and Electrochemistry Liaoning Province, School of Chemical Engineering, University of Science and Technology Liaoning, 185 Qianshanzhong Road, Anshan 114051, Liaoning, China.
Key Laboratory of Energy Materials and Electrochemistry Liaoning Province, School of Chemical Engineering, University of Science and Technology Liaoning, 185 Qianshanzhong Road, Anshan 114051, Liaoning, China; Liaoning Light Industry Institute Co., Ltd., 46 Taishan Road, Shenyang 110031, Liaoning, China.
J Colloid Interface Sci. 2024 Sep 15;670:204-214. doi: 10.1016/j.jcis.2024.05.081. Epub 2024 May 15.
Owing to highly theoretical capacity of 3579 mAh/g for lithium-ion storage at ambient temperature, silicon (Si) becomes a promising anode material of high-performance lithium-ion batteries (LIBs). However, the large volume change (∼300 %) during lithiation/delithiation and low conductivity of Si are challenging the commercial developments of LIBs with Si anode. Herein, a sandwich structure anode that Si nanoparticles sandwiched between carbon nanotube (CNT) and silicon carbide (SiC) has been successfully constructed by acetylene chemical vapor deposition and magnesiothermic reduction reaction technology. The SiC acts as a stiff layer to inhibit the volumetric stress from Si and the inner graphited CNT plays as the matrix to cushion the volumetric stress and as the conductor to transfer electrons. Moreover, the combination of SiC and CNT can relax the surface stress of carbonaceous interface to synergistically prevent the integrated structure from the degradation to avoid the solid electrolyte interface (SEI) reorganization. In addition, the SiC (111) surface has a strong ability to adsorb fluoroethylene carbonate molecule to further stabilize the SEI. Consequently, the CNT/SiNPs/SiC anode can stably supply the capacity of 1127.2 mAh/g at 0.5 A/g with a 95.6 % capacity retention rate after 200 cycles and an excellent rate capability of 745.5 mAh/g at 4.0 A/g and 85.5 % capacity retention rate after 1000 cycles. The present study could give a guide to develop the functional Si anode through designing a multi-interface with heterostructures.
由于在室温下锂离子存储的理论容量高达3579 mAh/g，硅（Si）成为高性能锂离子电池（LIBs）颇具前景的负极材料。然而，锂化/脱锂过程中巨大的体积变化（约300%）以及硅的低电导率，对含硅负极锂离子电池的商业发展构成了挑战。在此，通过乙炔化学气相沉积和镁热还原反应技术，成功构建了一种夹心结构负极，即硅纳米颗粒夹在碳纳米管（CNT）和碳化硅（SiC）之间。SiC作为刚性层抑制来自硅的体积应力，内部石墨化的CNT作为基体缓冲体积应力并作为导体传输电子。此外，SiC和CNT的组合可以缓解碳质界面的表面应力，协同防止整体结构退化，避免固体电解质界面（SEI）重组。此外，SiC（111）表面具有很强的吸附氟代碳酸乙烯酯分子的能力，可进一步稳定SEI。因此，CNT/SiNPs/SiC负极在0.5 A/g电流下可稳定提供1127.2 mAh/g的容量，200次循环后容量保持率为95.6%，在4.0 A/g电流下具有745.5 mAh/g的优异倍率性能，1000次循环后容量保持率为85.5%。本研究可为通过设计具有异质结构的多界面来开发功能性硅负极提供指导。
