Electrochemical behavior of carbon paper on cerium methanesulfonate electrolytes for zinc-cerium flow battery. (1st March 2015)

• Record Type: Journal Article
• Authors: Nikiforidis, Georgios; Xiang, Yan; Daoud, Walid A.
• Is Part Of: Electrochimica acta. Volume 157(2015)
• Page Start: 274
• Page End: 281
• Publication Date: 2015-03-01
• Subjects: Carbon paper -- cerium methanesulfonate -- mixed acid electrolytes -- redox flow battery; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2014.11.134
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: The voltammetric behavior of the Ce(III)/(IV) half-cell reaction in various electrolytes containing 0.6 M Ce was investigated on both pristine and metal-modified carbon paper (CP) electrodes at three different temperatures (25, 40 and 55 °C) in order to find the most favorable electrochemical conditions. The pristine CP displayed robust electrochemical performance for up to 200 repetitive CV cycles while the Pt loaded electrode's performance was stable for only 70 cycles, even though the latter exhibited a more reversible behavior, moving from a quasi-reversible to a reversible system ( Dox. = 4.0 × 10 −6 cm 2 s −1 and Dred. = 2.5 × 10 −6 cm 2 s −1 ). The In and La metal modified electrodes did not show any improvement with regard to the kinetics or reversibility of the reaction. The addition of 1 M H2 SO4 to the base electrolyte enhanced the cerium reduction reaction by a factor of 3, ( −7.2 × 10 −3 A cm −2 ). The highest exchange current densities (jo ) were achieved at 40 °C for the CP-Pt (1 × 10 −3 A cm −2 ) attributable to the presence of the catalytic Pt. Elevated temperatures (40 and 55 °C) improved D and ΔEp. while also the mass transport parameters a) dynamic viscosity (∼1.5 mPa·s) and b) electrolytic conductivity (∼265 mS cm −1 ) of the Ce(III)/(IV) half-cell reaction. Overall, pristine CP and to a lesser extent CP-Pt demonstrated good stability with prolonged cycling and kinetics comparable with the ones of Pt and Pt based electrodes.