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Fiber supercapacitors have attracted public attentions because of their merits of relatively high capacitance density, flexibility and easy integration with various electronic devices. In this work, a flexible coaxial-type fiber solid-state asymmetrical supercapacitor (ASC) based on Ni 3 S 2 nanorod array electrode and pen ink electrode was successfully fabricated. The Ni 3 S 2 nanorod array electrode was synthesized by directly growing Ni 3 S 2 nanorod arrays on a nickel wire through a facile hydrothermal method and the pen ink electrode as negative electrode was synthesized by a simple dip-coating method. The solid-state ASC device presents a stable voltage window of 1.4 V and behaves a high specific capacitance of 34.9 F g −1 (87.25 F cm −1 ) at a scan rate of 10 mV s −1 . Compared with the symmetric supercapacitor (SSC) based on Ni 3 S 2 electrodes, the ASC device provide an increased energy density of 8.2 Wh kg −1 (0.81 mWh cm −3 ) at the power density of 214.6 W kg −1 (21.12 mW cm −3 ). In addition, the ASC device also exhibits excellent electrochemical stability with 93.1% of initial specific capacitance after 3000 consecutive cycles and good mechanical stability. These encouraging results present its great potential in flexible solid-state energy storage devices. [ABSTRACT FROM AUTHOR]

In this work, three dimensional Co 9 S 8 nanorod@Ni(OH) 2 nanosheet core-shell structure is directly fabricated on flexible carbon cloth by a simple low temperature hydrothermal method. This structure with good electrochemical performance could be applied for supercapacitor electrode material. Firstly, this three dimensional structure possesses high specific capacitance of 1620 F g −1 , which is 1.7 times of the specific capacitance of the pure Ni(OH) 2 electrode and 2.5 times of that of the pure Co 9 S 8 electrode. Secondly, this hybrid electrode exhibits a very high energy density of 70.0 Wh Kg −1 at the power density of 305.7 W kg −1 . In addition, the hybrid electrode displays good cycling stability with 104.5% of the initial capacitance after 2000 continuous cycles. Furthermore, the hybrid electrode with three dimensional structure possesses excellent flexibility and has almost the same cyclic voltammetry curve under different bending angles. Thus, the designed electrode holds great promises for light weight, flexible, high energy density supercapacitor applications. [ABSTRACT FROM AUTHOR]