Double-cross-linked polyaniline hydrogel and its application in supercapacitors

Polyaniline-polyvinyl alcohol (PANI-PVA) hydrogels are widely used in supercapacitors due to their excellent electrochemical properties and unique functional hydrogel phase structure. However, the poor combinations between PANI and PVA are generally difficult to ensure the continuous electron transmission channel. Here, we utilized aminophenylboronic acid hydrochloride as a crosslinking agent to combine the PANI and PVA to form the chemical crosslinking, and the physical crosslinking of PVA occurs at low temperatures, which results in a porous double-cross-linked PANI-PVA hydrogel (PH-A). The chemical crosslinking between PANI and PVA ensures a continuous conduction path for the transmission of electrons. And the porous structure provides a larger contact area for electrochemical reactions. The PH-A shows a good electrochemical performance. The specific capacitance of the PH-A based supercapacitor is 237.0 mF/cm2 at 0.5 mA/cm2 current density. The capacitance retention rate of the capacitor is 86% after 1000 galvanostatic charge − discharge cycles. The unique dual-network structure can maintain mechanical performance when a large mechanical force is applied. The PH-A hydrogels have a good mechanical property with a breaking elongation of 601.8%.