Sandwich Configuration of Zinc Anode, Gel Electrolyte, and Radical Polymer Cathode for Fully Stretch‐Rechargeable Battery

Abstract Over the past decade, there is gradual development in fully stretchable semiconductors. However, to bring these devices to market, they require a reliable built‐in power source that can maintain stable output voltage, charge/discharge capabilities, and cycle life. Unfortunately, complex cell configurations have hindered the development of stretchable batteries. To overcome this, a fully stretch‐rechargeable battery with a sandwich configuration is fabricated. The cathode layer comprises electrically conductive poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and a redox‐active TEMPO‐substituted polymer, while the anode consists of a carbon nanotube layer deposited with zinc metal. By sandwiching a hydrogel between these two layers, a rechargeable battery is created that is attachable to human skin and <40 µm thick. This thin device offers a promising voltage of 1.8 V and is robust against repeated stretching, liquid leakage, and self‐discharging reactions induced by oxygen. This study is expected to open up new horizons for e‐skin and stretchable electronic fields.