碱性溶液中Ag_3O_4的电化学性质及反应机理  

Electrochemical Behavior and Reduction Mechanism of High Valence Silver Oxide Ag_3O_4 in Alkaline Solution

作　　者：程岩[1] 于明[1] 严曼明[1] 江志裕[1] 

机构地区：[1]复旦大学化学系,上海200433

出　　处：《电化学》2006年第2期134-139,共6页Journal of Electrochemistry

摘　　要：首次研究高价银氧化物Ag3O4(可看作为由Ag(Ⅲ)和Ag(Ⅱ)*组成)在碱性水溶液中的电化学性质和反应机理.循环伏安和XRD测试表明,Ag3O4在碱性溶液中的电化学还原过程比较复杂:在较慢的放电条件下,Ag3O4中的Ag(Ⅲ)按照Ag(Ⅲ)→Ag(Ⅱ)→Ag(Ⅰ)→Ag反应途径逐步还原为单质银;在较快的放电条件下,Ag(Ⅲ)可以直接被还原为Ag(Ⅰ),即Ag(Ⅲ)→Ag(Ⅰ)→Ag.而Ag(Ⅱ)*可直接还原成金属Ag.Ag3O4的理论放电容量可以达到553.1 mAh/g,比通常锌-氧化银电池所用AgO的电容量高出27.8%.在119C放电倍率下,Ag3O4的放电容量依然达到理论容量的83%.显示了作为新型化学电源材料的应用前景.The electrochemical properties of high-valence silver oxide Ag3O4in alkaline solution were investigated for the first time and the reduction mechanism of Ag3O4 was proposed. It can be recognized that Ag3O4consists of Ag （Ⅲ ） and Ag（ Ⅱ ） ^＊. From the results of vohammetry and XRD experiments it was found that the reduction process of Ag3O4 was more complicated. It could be electrochemically reduced through the series reactions of Ag （Ⅲ） →Ag （ Ⅱ ） →Ag （ Ⅰ ） →Ag（O） at low discharge rate or Ag （Ⅲ） →Ag （ Ⅰ ）→Ag（O） at higher discharge rate. And the Ag（ Ⅱ ） ^ could be reduced to Ag directly at low potential region. In addition, it is interesting to note that Ag3O4 presents the theoretical specific discharge capacity of 553.0mAh/g at high discharge rate, which is 27.8% higher than that of the commonly used cathodic material AgO in zinc/silver oxide battery. Under high discharge rate of 119C, Ag3O4 still presents the specific discharge capacity as high as 83% of theoretical value. Ag3O4 may have the attractive future for the use in alkaline batteries.

关 键 词：高价氧化银 Ag3O4 银锌电池 碱性电池 

分 类 号：O611.3[理学—无机化学]