K_2FeO_4-Zn电池在不同电解液中电化学行为研究  

Electrochemical behavior of K_2FeO_4-Zn battery in different electrolytes

作　　者：李昌家[1] 李景印[2] 李娜[2] 郭玉凤[3] 刘方方[1] 

机构地区：[1]河北科技大学化学与制药工程学院,河北石家庄050018 [2]河北科技大学理学院,河北石家庄050018 [3]河北科技大学环境科学与工程学院,河北石家庄050018

出　　处：《电源技术》2013年第11期1978-1980,1984,共4页Chinese Journal of Power Sources

基　　金：河北省科技支撑计划项目(11215114D);河北科技大学科研基金项目(XL200908)

摘　　要：采用次氯酸氧化法制备出纯度为97.5%的高铁酸钾,并利用IR、XRD、SEM等方法对所得样品进行了表征。高铁酸钾为正极、锌为负极,分别以10 mol/L KOH溶液和碱性离子液体[BMIM]OH的乙醇溶液为电解液组装成开放式模拟电池,并测试其在不同放电倍率下的放电性能。结果显示,以KOH溶液为电解液的K2FeO4-Zn电池放电曲线平稳,有较好的放电平台,但容量受到K2FeO4在水溶液中稳定性的制约,最高比容量在1 C倍率下为260 mAh/g,在碱性离子液体[BMIM]OH的乙醇溶液中电池却无法正常放电。利用线性伏安扫描和交流阻抗等方法对其原因进行了初步探讨发现,正负极在两种电解液中电化学行为均有所不同,其中以负极锌的差异最为明显,原因可能为两种电解液中OH-离子浓度差异所致,其中离子液体电解液中OH-含量仅为0.39 mol/L。对于K2FeO4-Zn电池体系,根据正负极成流反应特点,电解液需含一定浓度的OH-离子才能正常放电。Hypochlorite was used as oxidant to synthesize potassium ferrate, and its purity was 97.5%. IR, XRD and SEM were used to demonstrate the sample. Open analogue battery composed with potassium ferrate as cathode, Zn as anode, 10 mol/L KOH aqueous solution as electrolyte was tested at different discharge rates. The results show that the K2FeO4-Zn battery has steady discharge curve and good discharge potential plateau. But the discharge capacity is restricted by the stability of potassium ferrate in the aqueous solution; the highest specific capacity is 260 mAh/g at 1 C. But the battery composed with [BMIM]OH as electrolyte can＇t discharge. SLV and EIS are used to find out the reason. The results indicate that anode and cathode all have different electrochemical behavior in two electrolytes, especially the anode. The cause may be the different concentration of hydroxide ion in two electrolytes. The concentration of hydroxide ion in the ionic liquid is only 0.39 mol/L.According to the characteristic of K2FeO4-Zn battery system, the existence of plentiful hydroxide ion is necessary for K2FeO4-Zn battery to discharge successfully.

关 键 词：高铁酸钾 K2FeO4-Zn电池 电解液 离子液体 

分 类 号：TM912[电气工程—电力电子与电力传动]