Integrated Helical Fiber Electrode for Stable Ah‐Level Fast‐Charging Fiber Lithium‐Ion Batteries

Fiber lithium-ion batteries (FLIBs) represent a significant advancement in energy storage technology for wearable electronics, yet still suffer from unsatisfactory rate capability and power output due to the sluggish Li⁺ diffusion kinetics. Herein, the integrated helical fiber electrode (IHFE) configuration is proposed to optimize the Li⁺ transport path within the high-loading fiber electrode, thus promoting the Li⁺ diffusion kinetics. The IHFE design features a helical-wound ultrafine metal wire around a solid skeleton, which increases the specific surface area by 71.93% and shortens the Li⁺ transport path by 25%. Therefore, high-loading (100 mg m^-1) FLIBs with IHFE configuration achieve a 77.48% capacity retention under 4C (15-minute-fast-charging) conditions, which is 32.02% higher than the FLIBs with conventional solid fiber electrode (58.69%). Meanwhile, the elimination of lithium precipitation effectively promotes the cycling stability of IHFE-based FLIBs, delivering a 75.53% capacity retention rate after 300 continuous cycles under 4C fast-charging conditions. The practical feasibility of this strategic IHFE design is further validated via the stable operation of an Ah-level (1.09 Ah) energy textile with stable high-rate (4C) operation over 200 cycles.