Integrated Construction of a Long‐Life Stretchable Zinc‐Ion Capacitor

Abstract The major challenge in achieving high‐performance stretchable zinc‐ion energy‐storage devices is the combination of stretchable dendrite‐free zinc negative electrodes and sufficient bonding between components (current collector, electrode, separator, and package). Herein, based on a series of physicochemically tunable self‐healing polyurethanes, an elastic current collector is prepared through a swelling‐induced wrinkling method, and then a stretchable zinc negative electrode prepared through in situ confined electroplating. The elastic current collector has a nano‐network structure with polyurethane encapsulation, and exhibits both geometric and intrinsic stretchability. The stretchable zinc negative electrode formed in situ has high electrochemical activity and exhibits an excellent cycle life under the protection of a Zn²⁺‐permeable coating. Furthermore, fully polyurethane‐based stretchable zinc‐ion capacitors are assembled through in situ electrospinning and hot‐pressing techniques. Due to the high stretchability of the components and the interfusion of the matrixes, the integrated device exhibits excellent deformability and desirable electrochemical stability. This work provides a systematic construction plan for stretchable zinc‐ion energy‐storage devices in three aspects: material synthesis, component preparation, and device assembly.