Enhancing\nLithium-Ion Batteries with a 3D Conductive\nNetwork Silicon–Carbon Nanotube Composite Anode

To\nmeet the rising demand for energy storage, high-capacity Si\nanode-based lithium-ion batteries (LIBs) with extended cycle life\nand fast-charging capabilities are essential. However, Si anodes face\nchallenges such as significant volume expansion and low electrical\nconductivity. This study synthesizes a porous spherical Si/Multi-Walled\nCarbon Nanotube (MWCNT)@C anode material via spray drying, combining\nSi nanoparticles, MWCNT dispersion, sucrose, and carboxymethyl cellulose\n(CMC). The MWCNT incorporation creates a robust 3D conductive network\nwithin the porous microspheres, enhancing Li<sup>+</sup> diffusion\nand improving fast-charging/discharging performance. After 300 cycles\nat 1 A g<sup>–1</sup>, the material achieved a discharge capacity\nof 536.6 mA h g<sup>–1</sup> with 80.5% capacity retention.\nAdditionally, integrating a 3D network of Single-Walled Carbon Nanotubes\n(SWCNTs) further enhanced capacity retention in a binder-free, self-supporting\nelectrode created through vacuum filtration. The Si/MWCNT@C//LiFePO<sub>4</sub> full cell exhibited an initial Coulombic efficiency (ICE)\nexceeding 80%, with a specific capacity of 72.4 mA h g<sup>–1</sup> and 79.8% capacity retention after 400 cycles at 1 A g<sup>–1</sup>. This study offers a promising strategy for improving the performance\nand structural design of Si anodes.