Lignin-induced assembly of polyaniline on graphene via noncovalent interactions for energy storage

Abstract

The structural uniformity of polyaniline/reduced graphene oxide (PANI/RGO) composite directly affects its electron and ion transport behavior. We employed lignin (Lig) as a molecular modulator to induce the uniform assembly of PANI on graphene via π-π stacking and hydrogen bonding, enabling the construction of efficient charge transport channels. The resulting composite was integrated onto carbon cloth (CC) via vacuum filtration, followed by thermal reduction to construct an integrated three-dimensional (3D) porous PANI/Lig/RGO hydrogel/CC (PLRH/CC) integrated electrode. Benefiting from the Lig-regulated uniform microstructure and efficient interfacial connectivity, the PLRH/CC electrode achieved a specific capacitance of 676 F·g⁻¹ at 1 A·g⁻¹ and retained 82.2 % at 50 A·g⁻¹, demonstrating excellent rate performance. Moreover, after 10,000 charge-discharge cycles, it retains 84.1 % of its initial capacitance, demonstrating excellent durability. The symmetric solid-state supercapacitor based on the PLRH/CC electrode achieved an areal capacitance of 2.86 F·cm⁻² and an energy density of 572.20 μWh·cm⁻² (6.02 mWh·cm⁻³) at 20 mg·cm⁻² mass loading, indicating excellent application potential. This Lig-regulated approach provides new insights into the design of PANI/RGO electrodes and paves the way for their scalable production in practical supercapacitor applications.