Effects of Electrolyte Concentration, Temperature, Flow Velocity and Current Density on Zn Deposit Morphology
Effects of Electrolyte Concentration, Temperature, Flow Velocity and Current Density on Zn Deposit Morphology作者机构:CEST--Centre of Electrochemical Surface Technology GmbH Wiener Neustadt 2700 Austria Institute for Chemistry and Technology of Materials Graz University of Technology Graz 8010 Austria Cellstrom GmbH Wiener Neudorf 2355 Austria
出 版 物:《Journal of Energy and Power Engineering》 (能源与动力工程(美国大卫英文))
年 卷 期:2015年第9卷第11期
页 面:1019-1028页
学科分类:081702[工学-化学工艺] 081705[工学-工业催化] 08[工学] 0817[工学-化学工程与技术] 080502[工学-材料学] 0805[工学-材料科学与工程(可授工学、理学学位)]
主 题:Dendrite electrochemistry flow battery zinc zinc morphology.
摘 要:The most critical disadvantages of the Zn-air flow battery system are corrosion of the zinc, which appears as a high self-discharge current density and a short cycle life due to the non-uniform, dendritic, zinc electrodeposition that can lead to internal short-circuit. In our efforts to find a dendrite-free Zn electrodeposition which can be utilized in the Zn-air flow battery, the surface morphology of the electrolytic Zn deposits on a polished polymer carbon composite anode in alkaline, additive-free solutions was studied. Experiments were carried out with 0.1 M, 0.2 M and 0.5 M zincate concentrations in 8 M KOH. The effects of different working conditions such as: elevated temperatures, different current densities and different flow velocities, on current efficiency and dendrite formation were investigated. Specially designed test flow-cell with a central transparent window was employed. The highest Coulombic efficiencies of 80%-93% were found for 0.5 M ZnO in 8 M KOH, at increased temperatures (50-70 ℃), current densities of up to 100 ***2 and linear electrolyte flow velocities higher than 6.7 cm.s1.