Phenolic Resin-Based\nSilicon/Carbon Composites Modified\nwith Ultralow-Content Single-Walled Carbon Nanotubes via Liquid-Phase\nMixing Method for Lithium-Ion Batteries

Commercialization of silicon (Si) as an anode material\nin lithium-ion\nbatteries (LIBs) is hindered by its low electrical conductivity and\nsubstantial volume change during lithiation-delithiation. A promising\nsolution to address these issues lies in developing silicon/carbon\n(Si/C) composites. Herein, a liquid-phase mixing strategy is employed\nto combine nano-Si, phenolic resin (PF), and single-walled carbon\nnanotubes (SWCNTs, 0.05 wt %) with an optimal stirring speed of 3000\nrpm, which ensures uniform dispersion of SWCNTs without inducing oxidation\nof the nano-Si. After a high-temperature carbonization, the 3000-Si/SWCNTs/carbon-5\ncomposite (3000-SSC-5) is produced, features a unique structural configuration.\nIn this composite, the PF-based hard carbon effectively encapsulates\nnano-Si, suppressing its volume expansion, while the SWCNTs form a\nconductive network that significantly enhances electrical conductivity.\nWhen tested as an anode of LIBs, the 3000-SSC-5 electrode exhibits\nexcellent rate performance (1114 mAh g<sup>–1</sup> at 4 A\ng<sup>–1</sup>), and outstanding cycling performance (884 mAh\ng<sup>–1</sup> after 250 cycles at 0.5 A g<sup>–1</sup>). Furthermore, the full cell of 3000-SSC-5 <b>//</b> NCM811\nachieves a capacity retention rate of 82.3% after 1000 cycles, highlighting\nits superior long-term stability. This paper demonstrates that the\nelectrochemical properties of PF-based Si/C composites can be significantly\nenhanced through liquid-phase mixing with an ultralow content of SWCNTs.\nThe unique composite configuration and excellent electrochemical performance\nunderscore the promising potential of 3000-SSC-5 for commercial LIBs.