A First Outlook of Sputtered FeWO4 Thin Films for Micro-Supercapacitor Electrodes. Issue 3 (16th March 2021)

• Record Type: Journal Article
• Authors: Buvat, Gaëtan; Iadecola, Antonella; Blanchard, Florent; Brousse, Thierry; Roussel, Pascal; Lethien, Christophe
• Is Part Of: Journal of the Electrochemical Society. Volume 168:Issue 3(2021)
• Publication Date: 2021-03-16
• Subjects: FeWO4 -- multicationic oxides -- thin films -- Sputtering -- micro-supercapacitors -- Pseudocapacitance; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/1945-7111/abec57
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : The next generation of Internet of Things devices requires micro-supercapacitors operating at high voltage which is difficult to achieve using symmetrical design. Thus, their fabrication in an asymmetric configuration is mandatory. While MnO2 is well-established as positive electrode, the scarcity of existing efficient materials able to be used at the negative side drives the research towards new promising materials. Since few years, a new class of oxide materials, named multicationic oxides, were demonstrated to be attractive solutions as bulk electrodes for electrochemical capacitor. Among them, the wolframite-type FeWO4 oxide was proposed as an interesting negative electrode material for asymmetric FeWO4 /MnO2 electrochemical capacitors. The present paper reports for the first time on the successful thin film synthesis of such iron-tungstate oxide films by reactive DC magnetron sputtering, a deposition method widely used in the semiconductor industry to manufacture micro-devices. The pseudocapacitive behaviour documented at the bulk scale is preserved at the thin film level as well, and opens-up the possibility to use FeWO4 in the next generations of micro-supercapacitors.