Deposition of polyaniline nanofibers on activated carbon textile for high-performance pseudocapacitors

Abstract

Despite the widespread use of polyaniline as a pseudocapacitor material, the cycling stability and rate capability of polyaniline-based electrodes are of concern because of the structural instability caused by repeated volumetric swelling and shrinking during the charge/discharge process. Herein, nanofiber-structured polyaniline was synthesized onto activated carbon textiles to ensure the long-term stability and high-rate capability of pseudocapacitors. The nanoporous structures of polyaniline nanofibers and activated textile substrate enhanced the ion and electron transfer during charge/discharge cycles. The resulting pseudocapacitor electrodes showed high gravimetric, areal, and volumetric capacitance of 769 F g⁻¹, 2638 mF cm⁻², and 845.9 F cm⁻³, respectively; fast charge/discharge capability of 92.6% capacitance retention at 55 mA cm⁻²; and good long-term stability of 97.6% capacitance retention over 2000 cycles. Moreover, a symmetric supercapacitor based on polyaniline nanofibers exhibited a high energy of 21.45 Wh cm⁻³ at a power density of 341.2 mW cm⁻³ in an aqueous electrolyte.