Nanocrystalline FeWO4 as a pseudocapacitive electrode material for high volumetric energy density supercapacitors operated in an aqueous electrolyte

• Published in: Electrochemistry communications Vol. 57; no. 57; pp. 61 - 64
• Main Authors: Goubard-Bretesché, Nicolas, Crosnier, Olivier, Payen, Christophe, Favier, Frédéric, Brousse, Thierry
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.08.2015; Elsevier
• Subjects: Chemical Sciences; High density; Iron tungstate; Material chemistry; Neutral aqueous electrolyte; Pseudocapacitive behavior; Supercapacitor; Supercapacitor; Neutral aqueous electrolyte; High density; Pseudocapacitive behavior; Iron tungstate
• ISSN: 1388-2481; 1873-1902
• DOI: 10.1016/j.elecom.2015.05.007

Iron tungstate (FeWO4) has been synthesized using two low-temperature synthetic routes and investigated as a new pseudocapacitive electrode material for supercapacitors operating in a neutral aqueous electrolyte. Its electrochemical properties are clearly related to the specific surface area and seem to originate from Fe3+/Fe2+ fast surface reactions. For FeWO4 obtained by polyol-mediated synthesis, a high volumetric capacitance of 210F·cm−3 (i.e. more than two times higher than that of activated carbon) was measured at 20mV·s−1 with less than 5% fade over 10,000cycles. Furthermore, unlike most of the previously investigated iron based electrodes, a unique pseudocapacitive behavior is observed, thus emphasizing the role of the crystallographic structure on the electrochemical signature. [Display omitted] •FeWO4 was investigated as a pseudocapacitive electrode material.•It clearly displays a pseudocapacitive behavior in a neutral aqueous electrolyte.•A high volumetric capacitance of 210F·cm−3 was achieved at 20mV·s−1.•An excellent cycling ability is obtained in the potential range of −0.6/0V vs. Ag/AgCl.