Al3+ ion intercalation pseudocapacitance study of W18O49 nanostructure

• Main Authors: Thalji, Mohammad R., Ali, Gomaa A. M., Algarni, H., Chong, Kwok Feng
• Format: Article
• Language: English
• Published: Elsevier Ltd 2019
• Subjects: Q Science (General)
• Online Access: http://umpir.ump.edu.my/id/eprint/25908/1/Al3%20ion%20intercalation%20pseudocapacitance%20study%20of%20W18O49%20nanostructure.pdf; http://umpir.ump.edu.my/id/eprint/25908/; https://doi.org/10.1016/j.jpowsour.2019.227028; https://doi.org/10.1016/j.jpowsour.2019.227028

Intercalation pseudocapacitance is of essential significance for designing high performance electrode materials, which offers exceptional charge storage characteristics. In this study, we elucidate the pseudocapacitive behavior of Al3+ ions intercalation within the distinctive tunnels of monoclinic W18O49 nanostructure. 3D sea urchin-like W18O49 is synthesized through one-step solvothermal approach. Its physicochemical properties are investigated by X-ray diffraction, X-ray photoelectron spectroscopy, Field emission scanning electron microscopy and Brunauer-Emmett-Teller surface area analysis. Cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopy techniques are used to investigate the electrochemical characteristics of W18O49 electrode in different electrolyte systems. It shows high specific capacitance of 350 F g−1 at 1 A g−1, superior electrochemical long-term stability in the Al3+ electrolyte with 92% capacitance retention at 8000 cycles. The excellent electrochemical performance is predominantly due to the Al3+ ions intercalation/de-intercalation with W18O49 nanostructure that is proven by ex situ X-ray diffraction analysis. The work marks a notable achievement in the effort of substituting commonly acidic proton electrolyte for W18O49 supercapacitor.