Enhancing the interfacial reaction kinetics of CNT yarn-based Zn-V2O5 batteries via cone-spinning engineering

Flexible aqueous zinc-ion batteries (AZIBs) have emerged as promising candidates for wearable smart devices due to their inherent safety, mechanical adaptability, and eco-friendly aqueous electrolytes. However, practical implementation of yarn-shaped AZIBs remains challenged by insufficient capacity, non-uniform active material distribution, and limited energy density. Herein, we report a cone-spinning engineering strategy to fabricate carbon nanotube/vanadium pentoxide (CNT/V₂O₅) composite yarn cathodes with optimized architecture and Zn²⁺ storage capability. Compared with biscrolled counterparts, the cone-spun CNT/V₂O₅ yarn demonstrates exceptional electrochemical metrics, including a high areal capacity of 1.32 mAh cm⁻² at 1 mA cm⁻² and remarkable volumetric energy density of 168.76 mWh cm⁻³ at 145.80 mW cm⁻³. Notably, these values surpass most state-of-the-art yarn-based zinc-ion batteries reported to date. These advancements stem from the hierarchically engineered cathode architecture of cone-spun yarns, leading to the enhanced interfacial reaction kinetics. Additionally, the assembled yarn-shaped AZIBs can be utilized to efficiently store the solar energy to power wearable electronics. This work pioneers a hierarchical structural engineering strategy to achieve high-performance yarn-based AZIBs, paving the way for next-generation wearable energy storage systems.