Coaxial CoMoO4 nanowire arrays with chemically integrated conductive coating for high-performance flexible all-solid-state asymmetric supercapacitors

Abstract

Flexible all-solid-state supercapacitors have offered promising applications as novel energy storage devices based on their merits, such as small size, low cost, light weight and high wearability for high-performance portable electronics. However, one major challenge to make flexible all-solid-state supercapacitors depends on the improvement of electrode materials with higher electrical conductivity properties and longer cycling stability. In this article, we put forward a simple strategy to in situ synthesize 1D CoMoO₄ nanowires (NWs), using highly conductive CC and an electrically conductive PPy wrapping layer on CoMoO₄ NW arrays for high performance electrode materials. The results show that the CoMoO₄/PPy hybrid NW electrode exhibits a high areal specific capacitance of ca. 1.34 F cm⁻² at a current density of 2 mA cm⁻², which is remarkably better than the corresponding values for a pure CoMoO₄ NW electrode of 0.7 F cm⁻². An excellent cycling performance of nanocomposites of up to 95.2% (ca. 1.12 F cm⁻²) is achieved after 2000 cycles compared to pristine CoMoO₄ NWs. In addition, we fabricate flexible all-solid-state ASC which can be cycled reversibly in the voltage range of 0–1.7 V, and exhibits a maximum energy density of 104.7 W h kg⁻¹ (3.522 mW h cm⁻³), demonstrating great potential for practical applications in flexible energy storage electronics.