((北京航空航天大学 材料科学与工程学院，北京 100083))
摘 要: 采用电沉积技术制备几种电沉积式锌电极，考察镀液中KOH浓度和沉积电流密度对所制得镀锌层的微观形貌与性能的影响规律。结果表明：镀锌层的枝晶随着KOH浓度(250~400 g/L)的增加而变得粗大，且其析氢量、腐蚀电位和腐蚀电流密度均呈现先减小而后增加的趋势；随着电流密度(25~100 mA/cm2)的增长，镀锌层由块状结晶向枝晶转变，相应地电极反应活性随之增大，而耐蚀性则随之变差，并发现沉积电流密度为75 mA/cm2时，锌电极的综合性能最好，以200 mA/g充放电循环10周次，其放电容量仍可达504 mA∙h/g。解释了主要工艺参数对结晶形态及电极性能影响的原因，并说明适当的KOH浓度和沉积电流密度有利于提高电极的综合性能。
关键字: 锌电极；镀锌层；电沉积；微观形貌；循环寿命
（(School of Material Science and Engineering, Beihang University, Beijing 100083, China)）
Abstract:Several electrodeposited zinc electrodes were prepared by electrodeposition technique in order to investigate the influence of the concentration of KOH and current density on the micrograph and performance of galvanization coating. The results show that the dendritic deposits become bulky as the concentration of KOH (250−400 g/L) increases. Moreover the amount of hydrogen gas evolution, corrosion potential and corrosion current initially decrease and then increase. With increasing of current density (25−100 mA/cm2), the massive crystal grains of galvanization coating gradually change into dendritic formation, the reaction active of zinc electrode is accordingly raised and the property of corrosion resistance is depressed. In addition, it is found that the galvanization coating exhibits the best electrochemical and discharge performance when the current density is 75 mA/cm2. Its discharge capacity at the 10th charge-discharge cycle with a current of 200 mA/g achieves 504 mA∙h/g. The influence of chief process parameters on the morphology and properties of galvanization coating is also explained and it is confirmed that the appropriate concentration of KOH and current density are beneficial to improve the integrative performance of zinc electrode.
Key words: zinc electrode; galvanization coating; electrodeposition; micromorphology; cyclic life
