An Electrode‐Less Fiber Battery With 600 Wh/L‐Level Volumetric Energy Density Enabled by Dynamic Deposition Chemistry
Longmei Ma, Kun Zhang, Zhe Yang, Yi Jiang, Siwei Cao, You Pan, Chuang Wang, Qinhao Du, Shuxian Pang, Jiaxin Li, Haixin Yao, Xiaocheng Gong, Jiahe Qu, Tianrui Li, Yanan Zhang, Yiqing Cheng, Yuxuan Zhou, Fengliang Liu, Meng Liao, Chen Zhao, Yonggang Wang, Huisheng Peng, Bingjie WangABSTRACT
Aqueous fiber batteries are essential for next‐generation wearable electronics due to their inherent safety, low cost, and environmental friendliness. However, the low volumetric energy density (<100 Wh/L), stemming from the contradiction of insufficient spatial utilization and limited flexibility inherent to the pre‐coated fiber electrodes, significantly hinders their practical applications. Here, we introduce an ultrathin, electrode‐less fiber battery based on the dynamic deposition chemistry to decouple volumetric energy density from mechanical robustness. This battery addresses the core inefficiency of pre‐coated fiber batteries through dynamic deposition chemistry that dissolves redox‐active materials directly into the electrolyte, thereby eliminating the need for pre‐coated electrodes. This intrinsic design minimizes inactive material volume and facilitates on‐demand electrochemical deposition during operation. Thus, the resulting fiber battery achieves a high volumetric energy density of 612 Wh/L and an ultrathin diameter of 130 µm. Furthermore, its dynamic stiffness is reduced by three orders of magnitude compared to pre‐coated counterparts. This study unveils a new technological pathway for fiber batteries with high volumetric energy density. Simultaneously, it establishes a novel, material‐efficient architectural paradigm that seamlessly integrates into high‐performance textiles, enabling future wearable devices.