In situ XRD and operando spectra-electrochemical investigation of tetragonal WO3-x nanowire networks for electrochromic supercapacitors

Abstract Electrochromic supercapacitors (ESCs) are appealing for smart electronic device applications due to their advantages of dual-function integration. Unfortunately, the synchronous evaluation and essential reaction mechanism ambiguous. Herein, we constructed a 3D WO 3-x nanowire networks/fluorine-doped tin oxide (WO NWNs/FTO) bifunctional electrode ESCs by solvothermal self-crystal seeding method. The correspondence relationship between optical electrochemical performances NWNs/FTO was explored using an operando spectra-electrochemical characterization It reveals excellent areal capacity 57.57 mF cm ?2 with high corresponding modulation (?T) 85.05% optical-electrochemical cycling stability. Furthermore, synergistic Al 3+ ion intercalation behavior surface pseudocapacitance during is revealed utilizing in situ X-ray diffraction. Based on these results, ESC pairing /FTO as cathode V 2 O 5 nanoflowers/FTO (V NFs/FTO) anode, which simultaneously deliver large modulation. Moreover, energy storage level could be visually monitored rapid reversible color transitions real time. This work provides promising pathway developing multi-functional integrated supercapacitors.