Preparation Of Ni By Molten Salt Electrolysis From Nano-NiO

This paper is on the basis of FFC Cambridge process. In order to improve theelectrolysis efficiency of the process, the experiment uses nano-NiO as raw material toprepare cathodes and metal Ni by molten salt electrolysis.Nano-NiO can be prepared by sol-gel biotemplate method, in which egg membrane isas template and citric acid is as chelating agent in the preparation for a stable sol-gel. Withthe increase of sintering temperature, the nano-NiO crystal type will keep unchanged.However, the increase of sintering temperature will cause the diameter grow, specificcapacitance decrease. When the sintering temperature is400℃, the grain growth is notcompletely leading to the specific capacitance decrease; With the increase of sintering timenano-NiO will cause the diameter grow and the specific capacitance decrease, however, afew Impurities can be seen after sintering1h, resulting in the specific capacitance; With theincrease of Ni2+will cause the diameter grow, resulting in the specific capacitance. Toprepare nano-NiO under optimal conditions, the largest specific capacitance is198.1F/g.After100cycles, the discharge capacitance will decrease to177F/g, which indicate thatNiO has a good circulation charge and discharge performance.Nano-NiO powders are compacted into pellets, sintered, so that it can be used ascathodes. High-density graphite is used as anode. Electrolysis is performed in CaCl2andchange of current during electrolysis is recorded. Composition of pellet is analyzed byXRD and SEM.The infiuence of compact pressure, sintering temperature, sintering time, electrolytictemperature, electrolytic time and cell voltage on morphology and electrolysis process arestudied. After comparing the differences of nano-sized metal oxides and the common metaloxides in the electrolytic process, the results show that the optimal conditions to obtainmetal Ni are: nano-NiO pellets are compacted at10MPa, when sintered at900℃for8hand electrolyzed under2.5V in CaCl2at850℃. The current efficiency in above conditionis46.89%, higher than the normal NiO current efficiency36.7%. The energy consumptionis6230.13KW h t1. Therefore, to electrolyze nano-NiO is propitious to deoxy, shortenthe time of electrolysis and increase the electrolytic efficiency.Figure34; Table9; Reference67...