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.