Restricted growth of polyaniline nanofiber arrays between holey graphene sheets on carbon cloth towards improved charge storage capacity

Abstract

The rapid−growing demand for flexible and wearable electronics has driven increased interest in developing porous electrodes with outstanding charge storage capacity especially areal capacity for polymeric and hybrid supercapacitors. Herein, unique porous polyaniline/holey graphene/carbon cloth (PANI/HG/CC) composite electrodes were constructed by combining rapid frozen interfacial polymerization and layer−by−layer spraying to restrict the growth of PANI nanofiber arrays between carbon−based materials. Benefiting from rapid charge transport, more electroactive sites and improved electrolyte penetration provided by hierarchical porous structure and highly oriented PANI nanofibers in the composite (P − G) by growing directly PANI array on the CC and applying graphene sheets as interlayer and cover layer, an areal specific capacitance of 3.22 F cm⁻² at 5 mA cm⁻² was achieved. A maximum areal energy density of up to 104.86 μWh cm⁻², and excellent capacity retention of 89.5 % at 20 mA cm⁻² after 5000 cycles also were achieved for flexible symmetric all−solid−state supercapacitor. Furthermore, the zinc−ion hybrid supercapacitor (P − G||Zn) assembled with P − G cathode and Zn anode could display a capacity of 217.7 mAh g⁻¹ at 0.2 A g⁻¹, and the maximum energy density of 130.6 Wh kg⁻¹ at the power density of 120 W kg⁻¹.