Multifunctional Carbon Fiber–Nanotube Frameworks for Safe, Recyclable, High-Performance Lithium-Ion Batteries

Abstract

This study introduces a multifunctional carbon fiber–carbon nanotube (CFCNT) architecture as a lightweight, thermally stable, and recyclable current collector for lithium-ion batteries (LIBs). Compatible with both graphite anodes and LiFePO₄ cathodes, the CFCNT platform reduces collector mass to 4.4 mg/cm²—substantially lower than conventional copper (10.1 mg/cm²) and aluminum (5.1 mg/cm²) while enhancing electrical conductivity and interfacial stability. Full pouch cells employing CFCNT collectors achieve an initial capacity of 153 mAh/g and retain 126 mAh/g after 150 cycles (0.11% fade per cycle), with > 91% coulombic efficiency. Safety testing reveals minimal thermal response (< 2°C rise) during nail penetration, underscoring robust mechanical and electrochemical resilience. Critically, the architecture enables direct recovery and reuse of electrodes and current collectors, supporting a closed-loop recycling strategy. These results position CFCNT collectors as a viable pathway toward safer, high-performance, and circular energy storage technologies.