Single‐Piece Membrane Supercapacitor with Exceptional Areal/Volumetric Capacitance via Double‐Face Print of Electrode/Electrolyte Active Ink
Zhenyun Zhao, Dongliang Chen, Ming Lu, Jingwen Lin, Yang Hou, Qinghua Zhang, Zhongjian Li, Jiao Lei, Zhizhen Ye, Jianguo Lü
Abstract
Abstract Single‐piece flexible supercapacitors (FSCs) have light and ultrathin superiorities, thereby having great potential in portable/wearable electronics. However, all the available single‐piece FSCs are fabricated by in situ growth routes, which are incompatible with large‐scale technology. This work designs a carboxymethyl cellulose/phytic acid/polyaniline ink, incorporating electrode with electrolyte active compositions. Based on the electrode/electrolyte active ink, a double‐face print technique on mixed cellulose ester and nylon membranes to fabricate single‐piece membrane‐FSCs, where both sides of membranes can be utilized well, is proposed. Consequently, one FSC is measured to be only ≈0.785 cm 2 in area, ≈0.021 g in weight, and ≈200 µm in thickness, while it has exceptional areal and volumetric capacitances up to 757 mF cm −2 and 37.8 F cm −3 , respectively, based on the entire device. It also exhibits high flexibility with a capacitance retention of 98% after 2000 bend cycles from 0° to 180°. The state‐of‐the‐art FSCs are expected to have exciting prospects in portable/wearable electronics, smart reading, and flexible displays. The preparation strategy renders the massive production of large‐area and mini‐size arrayed FSCs, and also the “do‐it‐yourself” or homemade preparation, which adds more interest and designability for general users.