Yan Zhong

Enhanced cycling stability of NiCo 2 S 4 @NiO core-shell nanowire arrays for all-solid-state asymmetric supercapacitors

As a new class of pseudocapacitive material, metal sulfides possess high electrochemical performance. However, their cycling performance as conventional electrodes is rather poor for practical applications. In this article, we report an original composite electrode based on NiCo2S4@NiO core-shell nanowire arrays (NWAs) with enhanced cycling stability. This three-dimensional electrode also has a high specific capacitance of 12.2 F cm−2 at the current density of 1 mA cm−2 and excellent cycling stability (about 89% retention after 10,000 cycles). Moreover, an all-solid-state asymmetric supercapacitor (ASC) device has been assembled with NiCo2S4@NiO NWAs as the positive electrode and active carbon (AC) as the negative electrode, delivering a high energy density of 30.38 W h kg−1 at 0.288 KW kg−1 and good cycling stability (about 109% retention after 5000 cycles). The results show that NiCo2S4@NiO NWAs are promising for high-performance supercapacitors with stable cycling based on the unique core-shell structure and well-designed combinations.

Construction of porous CuCo 2 S 4 nanorod arrays via anion exchange for high-performance asymmetric supercapacitor

To push the energy density limit of supercapacitors, proper pseudocapacitive materials with favorable nanostructures are urgently pursued. Ternary transition metal sulfides are promising electrode materials due to the better conductivity and higher electrochemical activity in comparison to the single element sulfides and transition metal oxides. In this work, we have successfully synthesized porous CuCo2S4 nanorod array (NRAs) on carbon textile through a stepwise hydrothermal method, including the growth of the Cu-Co precursor nanowire arrays and subsequent conversion into CuCo2S4 NRAs via anion exchange reaction. The CuCo2S4 NRAs electrode exhibits a greatly enhanced specific capacitance and an outstanding cycling stability. Moreover, an asymmetric supercapacitor using the CuCo2S4 NRAs as positive electrode and activated carbon as negative electrode delivers a high energy density of 56.96 W h kg−1. Such superior performance demonstrate that the CuCo2S4 NRAs are promising materials for future energy storage applications.

Novel Integration of Perovskite Solar Cell and Supercapacitor Based on Carbon Electrode for Hybridizing Energy Conversion and Storage

Power packs integrating both photovoltaic parts and energy storage parts have gained great scientific and technological attention due to the increasing demand for green energy and the tendency for miniaturization and multifunctionalization in electronics industry. In this study, we demonstrate novel integration of perovskite solar cell and solid-state supercapacitor for power packs. The perovskite solar cell is integrated with the supercapacitor based on common carbon electrodes to hybridize photoelectric conversion and energy storage. The power pack achieves a voltage of 0.84 V when the supercapacitor is charged by the perovskite solar cell under the AM 1.5G white light illumination with a 0.071 cm2 active area, reaching an energy storage proportion of 76% and an overall conversion efficiency of 5.26%. When the supercapacitor is precharged at 1.0 V, an instant overall output efficiency of 22.9% can be achieved if the perovskite solar cell and supercapacitor are connected in series, exhibiting great potential in the applications of solar energy storage and flexible electronics such as portable and wearable devices.