Dissolution behavior of Co-coated NiO cathode in molten (Li0.62K0.38)2CO3 eutectics

• Published in: Journal of power sources 2004-10, Vol.137 (1), p.62-70
• Main Authors: RYU, B. H, HAN, J, YOON, S. P, NAM, S. W, LIM, T.-H, HONG, S.-A, KIM, K. B
• Format: Article
• Language: English
• Subjects: Applied sciences; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Energy; Energy. Thermal use of fuels; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Fuel cells
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2004.05.037

The dissolution behavior of the NiO-CoO electrodes in molten (Li0.62K0.38)2CO3 eutectics as a function of Co content was investigated under the standard cathodic gas composition at 650 DGC. In order to prepare NiO-CoO electrodes, Co was deposited on the porous Ni electrode using galvanostatic pulse plating technique followed by the oxidation process. Compared to the pure NiO electrode, NiO-CoO electrodes showed low Ni solubility in molten (Li0.62K0.38)2CO3 eutectics. Solubility of NiO-CoO electrodes depended on the partial pressure of carbon dioxide (PcO2) and the Ni solubility increased with Pco2. On the other hand, the Ni solubility was not affected by the partial pressure of oxygen (PO2). The XRD analysis after the dissolution experiment, showed that the Ni solubility decreased with increase of the amount of lithium incorporated in the electrodes and that the lithium incorporation was promoted by the formation of NiO-CoO solid solution. The results obtained in the present study suggested that NiO-CoO solid solution could effectively suppress the NiO dissolution in the molten (Li0.62K0.38)2CO3 eutectics.