New insight in the cyclic voltammetric behaviour of nickel in molten Li2CO3–Na2CO3 at 650°C

II. Structural, morphological, chemical and electrochemical analysis of nickel covered by electrochemically deposited Co3O4 in molten Li2CO3–Na2CO3 at 650 °C

“…In the case of the NiO substrate, the peaks located at À1.49 V vs Ag|Ag + and À0.82 V vs Ag|Ag + are attributed to LiCoO 2 , but peaks due nickel also interfere. According to a previous study [8,22], the reduction of NiO into NiðNiO þ CO 2 þ 2e À () Ni þ CO 2À 3 Þ occurs at À1.2 vs Ag|Ag + to À1.3 V vs Ag|Ag + , under similar experimental conditions. Thus the I c1 shoulder visible on the voltammogram of the LiCoO 2 -coated NiO electrode can most probably be attributed to this reduction.…”

Morphological, structural and electrochemical analysis of sputter-deposited ceria and titania coatings for MCFC application

“…4 corresponds to a deposit of 0.6 m after 1 h of immersion in the carbonate melt. The characteristic peaks of NiO/Ni system, fully depicted by Belhomme et al [21], are not observed, confirming that nickel is well protected by the titanium oxide, in a Li 2 TiO 3 form. Therefore, peaks I c1 , I c2 , I c4 and I a1 can be due to the presence of titanium species.…”

“…It most probably represents the nickel redox system: Ni + CO 3 2− → NiO + CO 2 + 2e − (in a simplified way, knowing that NiO is under a Li x Ni 1−x O, with x = 0.002 [22]. According to the literature [21], this system appears, in principle, at −1.2 V/Ag|Ag + ; the slight potential shift can be due to a lower kinetics in our present case. The peaks, initially present after 1 h immersion, fully disappeared after 24 h of immersion in the melt, showing that the surface of the sample is mainly recovered by lithiated nickel oxide and that the TiO 2 coating fell into the melt.…”

Corrosion-electrochemical behavior of nickel in an alkali metal carbonate melt under a chlorine-containing atmosphere

“…When studying the oxidation and lithiation of nickel in a carbonate melt under the operating conditions of a melt-carbonate fuel cell, the authors of [3][4][5][6][7][8][9][10][11] found that the rate controlling step of this process is the diffu sion of oxygen toward the electrode surface. Partial replacement of an atmosphere made of a mixture of oxygen and carbon dioxide over a carbonate melt by gaseous chlorine should affect the corrosion and the I-V characteristics of a nickel electrode.…”