((北京航空航天大學(xué) 材料科學(xué)與工程學(xué)院，北京 100083))
摘 要: 采用電沉積技術(shù)制備幾種電沉積式鋅電極，考察鍍液中KOH濃度和沉積電流密度對所制得鍍鋅層的微觀形貌與性能的影響規(guī)律。結(jié)果表明：鍍鋅層的枝晶隨著KOH濃度(250~400 g/L)的增加而變得粗大，且其析氫量、腐蝕電位和腐蝕電流密度均呈現(xiàn)先減小而后增加的趨勢；隨著電流密度(25~100 mA/cm2)的增長，鍍鋅層由塊狀結(jié)晶向枝晶轉(zhuǎn)變，相應(yīng)地電極反應(yīng)活性隨之增大，而耐蝕性則隨之變差，并發(fā)現(xiàn)沉積電流密度為75 mA/cm2時，鋅電極的綜合性能最好，以200 mA/g充放電循環(huán)10周次，其放電容量仍可達504 mA∙h/g。解釋了主要工藝參數(shù)對結(jié)晶形態(tài)及電極性能影響的原因，并說明適當?shù)?/SPAN>KOH濃度和沉積電流密度有利于提高電極的綜合性能。
關(guān)鍵字: 鋅電極；鍍鋅層；電沉積；微觀形貌；循環(huán)壽命
（(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
