Sucrose in situ physically cross-linked of polyaniline and polyvinyl alcohol to prepare three-dimensional nanocomposite hydrogel with flexibility and high capacitance

Polyaniline (PANI) composite hydrogels with a combination of excellent mechanical and electrochemical properties are promising for the development of flexible wearable devices. Generally, the preparation of a PANI hydrogel requires two steps. Either the polyvinyl acetate (PVA) flexible network is first prepared, followed by the addition of aniline and initiator, or a PANI powder is prepared first and then dispersed in a polyvinyl alcohol solution to form a hydrogel through the freeze-thaw cycle. In this work, we report a simple and effective strategy to synthesize polyaniline nanocomposite hydrogels. A PANI hydrogel electrode with a specific flexibility and excellent electrochemical performance was fabricated in one step by utilizing the hydrogen bonding cross-linking effect between sucrose and PANI and PVA. The three-dimensional network PANI hydrogel capacitor obtained by physical cross-linking exhibited appreciable capacitance performance and excellent rate performance. When the current density was 1 mA/cm2, the specific areal capacitance of the device reached 500.2 mF/cm2. When the current density increased 10-fold, the capacitance retention rate was 55.1%. This research proposes a novel solution for designing and developing energy storage hydrogels with several potential applications such as artificial skin, motion detection, and wearable electronics.