Flexible superior electrode architectures based on three-dimensional porous spinous α-Fe2O3 with a high performance as a supercapacitor

Abstract

Flexible supercapacitors have recently attracted increasing attention as they show unique promising advantages, such as flexibility and shape diversity, and they are light-weight and so on. Herein, we designed a series of 3D porous spinous iron oxide materials synthesized on a thin iron plate through a facile method under mild conditions. The unique nanostructural features endow them with excellent electrochemical performance. The electrochemical properties of the integrated electrodes as active electrode materials for supercapacitors have been investigated using different electrochemical techniques including cyclic voltammetry, and galvanostatic charge–discharge in Na₂SO₄ and LiPF₆/EC : DEC electrolyte solutions. These integrated electrodes showed high specific capacitance (as high as 524.6 F g⁻¹ at the current density of 1 A g⁻¹) in 1.0 M Na₂SO₄ (see Table S1). Moreover, the integrated electrodes also show high power densities and high energy densities in a LiPF₆/EC : DEC electrolyte solution; for example, the energy densities were 319.3, 252.5, 152.1, 74.13 and 38.6 W h kg⁻¹ at different power densities of 8.81, 21.59, 56.65, 92.09 and 152.64 kW kg⁻¹, respectively. Additionally, the flexible superior electrode exhibited excellent stability with capacitance retention of 92.9% after 5000 cycles. Therefore, such flexible integrated devices might be used in smart and portable electronics.