Silicon-based anodes are considered ideal candidate materials for nextgenerationlithium-ion batteries due to their high capacity. However, the lowconductivity and large volume variations during cycling inevitably result ininferior cyclic stability. Herein, a dry method without binders is designed tofabricate Si-based electrodes with single-walled carbon nanotubes (SWCNTs)network and to explore the different mechanisms between SWCNT and multiwalledcarbon nanotubes (MWCNTs) as a conductive network. As expected,higher initial discharge capacity (1785 mAh g~(?1)), higher initial Coulombicefficiency (ICE, 81.52%) and outstanding cyclic stability are obtained from theSiO_x@C|SWCNT anodes. Furthermore, its lithium-ion diffusion coefficient(D_(li+)) is 3–4 orders of magnitude higher than that of SiO_x@C|MWCNT. Theunderlying mechanism is clarified by in situ Raman spectroscopy and theoreticalanalysis. It is found that the SWCNTs can maintain good contact withSiO_x@C even under tensile stresses up to 6.2 Gpa, while the MWCNTs loseelectrical contact due to alternating compressive stress up to 8.9 Gpa andtensile stress up to 2.5 Gpa during long-term cycling. Under such very largestresses, the more flexible SWCNTs and their stronger van der Waals forcesensure that SiO_x@C still has good contact with SWCNTs.
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