3D Printing‐Directed Synergistic Design of High‐Performance Zinc‐Ion Hybrid Capacitors and Nanogenerators for All‐In‐One Self‐Powered Energy Wristband

Abstract Advanced wearable self‐powered energy systems that simultaneously achieve energy harvesting and energy storage offer exciting opportunities for flexible electronics, information communication, and even intelligent environmental monitoring. However, building and integrating synergistic energy storage from energy harvester unit into a single power source is highly challenging. Herein, a unique 3D printing‐directed synergistic design of high‐performance zinc‐ion hybrid capacitors (ZIHCs) and triboelectric nanogenerators (TENGs) is proposed for the all‐in‐one self‐powered wearable energy wristband. With advanced ink design, high‐performance flexible ZIHCs are built up as the excellent energy storage unit with remarkable electrochemical behaviors and synergistic matching from TENGs. An exceptional device capacitance of 239.0 mF cm⁻², moderate potential window, high‐rate capability, robust cycling stability, and excellent flexibility are achieved. Intrinsic charge storage process is also revealed, further demonstrating the outstanding electrochemical stability of the in‐plane flexible ZIHCs. Moreover, using 3D printing‐directed synergistic design, an advanced all‐in‐one self‐powered energy wristband is developed, where an efficient harvesting of body vibration/movement energy and a reliable storage of harvested energy are simultaneously realized, representing a substantial step toward future practical applications in portable and wearable electronics.