Carbon Textile Decorated with Pseudocapacitive VC/Vx Oy for High-Performance Flexible Supercapacitors

Abstract

It is demonstrated that, via V₂ O₅ coating by low temperature atomic layer deposition and subsequent pyrolysis, ubiquitous cotton textile can readily turn into high-surface-area carbon textile fully decorated with pseudocapacitive V_x O_y /VC widely usable as electrodes of high-performance supercapacitor. It is found that carbothermic reduction of V₂ O₅ (C + V₂ O₅ → C' + VC + CO/CO₂ (g)) leads to chemical/mechanical activation of carbon textile, thereby producing high-surface-area conductive carbon textile. In addition, sequential phase transformation and carbide formation (V₂ O₅ → V_x O_y → VC) occurred by carbothermic reduction trigger decoration of the carbon textile with redox-active V_x O_y /VC. Thanks to the synergistic effect of electrical double layer and pseudocapacitance, the supercapacitors made of the hybrid carbon textile exhibit far better energy density (over 30-fold increase) with excellent cycling stability than the carbon textile simply undergone pyrolysis. The method can open up a promising and facile way to synthesize hybrid electrode materials for electrochemical energy storages possessing advantages of both electrical double layer and pseudocapacitive material.

Keywords: atomic layer deposition; carbothermic reduction; hybrid textile; supercapacitors.