Single-step hydrothermal synthesis of WO3-MnO2 composite as an active material for all-solid-state flexible asymmetric supercapacitor

• Published in: International journal of hydrogen energy 2018-02, Vol.43 (5), p.2869-2880
• Main Authors: Shinde, Pragati A., Lokhande, Vaibhav C., Patil, Amar M., Ji, Taeksoo, Lokhande, Chandrakant D.
• Format: Article
• Language: English
• Subjects: Asymmetric supercapacitors; Composites; Energy storage; MnO2; WO3; WO3- MnO2
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2017.12.093

In present study, new strategy is employed to build composite nanostructure and asymmetric configuration to enhance the capacitive performance of supercapacitor device. The WO3-MnO2 composite with mesoporous structure is prepared by single-step hydrothermal method and used to gain superior electrochemical performance in asymmetric configuration. A binder-free and additive-less WO3-MnO2 composite electrode exhibits high specific capacitance of 609 F g−1 at a scan rate of 5 mV s−1. The flexible asymmetric supercapacitor device with WO3-MnO2 as a positive electrode and WO3 as a negative electrode demonstrates stable operating potential window of 1.4 V with specific capacitance of 103 F g−1 at a scan rate of 5 mV s−1 and energy density of 24.13 Wh kg−1 at power density of 915 W kg−1. Furthermore, WO3-MnO2//WO3 device exhibits good cycle life with capacity retention of 95% after 2500 cycles and excellent mechanical flexibility. These results reveal the potential of WO3-MnO2 composite electrode for fabrication of high-performance supercapacitors. •WO3-MnO2 electrode was successfully fabricated by single-step hydrothermal method.•Synergistic effect between constituent phases enhances the electrochemical performance.•The asymmetric supercapacitor exhibits high energy and power density.