Non-stationary electrochemical synthesis of flexible binder-free hybrid electrode materials for supercapacitors

Abstract

The rapid development of flexible energy storage devices, such as supercapacitors, requires the creation of appropriate electrode materials with high capacitance and cycling stability. In this work, we propose a new method for the synthesis of hybrid electrode materials by depositing transition metal oxides on carbon fabrics using non-stationary electrolysis. An amorphous deposit with inclusions of Mo4O11, MoO3, MoO2, Mo8O23, Mo9O26, V2O5, and MnO2 nanocrystals was obtained on the carbon surface. The hybrid was used as a binder-free electrode and had a capacitance of 498 mF∙cm–2 in 2 M KOH electrolyte at a current density of 4 mA∙cm–2. This value is comparable to or even higher than the values reported for similar materials. A long-term test of the two-electrode system showed a capacitance retention of 62% over 10,000 cycles. The power density and energy density of the hybrid electrode are 15∙10–4 W∙cm–2 and 6∙10–7 Wh∙cm–2, respectively. The synthesized metal oxide/carbon hybrids are promising electrode materials for symmetrical supercapacitors with alkaline electrolytes.