Organic-inorganic hybrid electrode engineering for high-performance asymmetric supercapacitor based on WO3-CeO2 nanowires with oxygen vacancies

Abstract Although WO3 with high theoretical capacitance has a future in the field of energy storage, its electrode processing to obtain high capacitance is still a challenge. Here, we propose an innovative electrode structure design by utilizing PEDOT and PEDOT:PSS to sequentially assemble with the oxygen vacancies-enriched WO3 and WO3-CeO2 hybrid nanowires on the glassy carbon (GC). As-prepared PEDOT:PSS/WO3/PEDOT/GC and PEDOT:PSS/WO3-CeO2/PEDOT/GC electrodes show high areal capacitance of 1139.6 and 1310 mF cm-2 at 2 mA cm-2, respectively, greater than 822.3 mF cm-2 of the WO3-PTFE-C/GC. The asymmetric supercapacitor based on PEDOT:PSS/WO3-CeO2/PEDOT and PEDOT:PSS/RuO2/PEDOT electrodes works at 1.6 V high working voltage, delivers an energy density of 0.61 Wh m-2 at power density of 8.22 W m-2. Therefore, the electrode structure design will be suitable to improve the capacitance performance of other low-conductivity active materials.