Engineering robust and electrochemically active polyvinyl alcohol/polyaniline hydrogels by halloysite nanotube-guided 3D porous networks

HNT enables 3D porous network and suppresses PANI aggregation. • Synergistic enhancement of mechanical and electrochemical properties. • High areal capacitance (285 mF cm –2 ) and energy density (25.33 µWh cm –2 ). • Excellent cycling stability (85.11% after 10,000 cycles) and flexibility. With the rapid advancement of flexible electronics, the demand for energy storage devices capable of withstanding mechanical deformation has become increasingly pressing. To address the challenges of polyaniline agglomeration in conductive polymer hydrogels and the difficulty of synergistically enhancing both mechanical and electrochemical properties, this study presents a PVA/PANI/HNT composite hydrogel fabricated by incorporating hollow nanotubular halloysite (HNT), which not only suppresses PANI agglomeration through electrostatic interactions but also serves as a nanoscale scaffold to construct a 3D nanoporous network structure, significantly enhancing the specific surface area, mechanical strength, and electron/ion transport of the hydrogel. The resulting solid-state supercapacitor exhibits exceptional electrochemical performance, including an areal capacitance of 285 mF cm –2 , energy and power densities of 25.33 µWh cm –2 and 3991.65 µW cm –2 , respectively, and a capacitance retention of 85.11% after 10,000 charge–discharge cycles. Furthermore, the device maintains stable electrochemical performance under 180° bending conditions, demonstrating promising application potential in flexible wearable electronics. Download: Download high-res image (334KB) Download: Download full-size image