Revealing the Impact of the Binder Content on Solvent-Free PTFE-Based SiO x /C Composite Electrodes for High-Energy-Density Lithium-Ion Batteries

Solvent-free electrode fabrication technologies present a promising alternative to conventional wet processes, lowering lithium-ion battery production costs while improving the energy density and manufacturing efficiency. In this study, solvent-free SiOx/C composite electrodes were prepared via polytetrafluoroethylene (PTFE) fibrillation to explore their potential for high-energy-density lithium-ion battery applications. The impact of the PTFE content on the mechanical properties, morphological characteristics, and electrochemical performances of the composite electrodes was systematically investigated. The experimental results demonstrate that PTFE-based SiOx/C electrodes with 5% binder content exhibit optimal fracture elongation and cycling stability. Comparative analysis shows that at equal binder content, solvent-free PTFE-based electrodes exhibit over 20 times higher fracture elongation than conventional wet-processed electrodes and maintain superior structural integrity during charge/discharge cycling. Additionally, the solvent-free process yields a denser microstructure, achieving up to 117.6% higher volumetric capacity compared to wet-processed electrodes.