Integratable Paper‐Based Iontronic Power Source for All‐In‐One Disposable Electronics

Abstract With the emergence of disposable electronics, compatible safe, flexible, and recyclable power sources have become a critical challenge. Here, an ultra‐thin paper‐based iontronic power source is enabled by highly efficient translational Li + transport within 2D nanofluidic channels of graphene oxide under a salinity gradient and the fine‐tuned interfacial redox reactions. The paper‐based source can generate volumetric power and energy densities of 438.02 mW cm −3 and 30.02 mWh cm −3 , respectively. Its areal power density is 1095.05 mW cm −2 , surpassing most flexible batteries. It maintains a working state when bent or even cut and can be simply recycled by incineration. By filling 2D nanofluidic inks in different pens, the power source can be drawn on paper when needed, which not only overcomes the inherent defect of self‐discharge for most batteries but also enables writing directly on any insulating substrates. Furthermore, all‐in‐one disposable electronics comprised of an energy management system (paper‐based triboelectric nanogenerator and iontronic power source) and wireless sensing system (temperature sensor with NFC circuits) are integrated onto one piece of paper by duplex printing, demonstrating the huge potential of such integratable iontronic power sources for soft, wireless, and conformable disposable electronics.