物理化学学报 >> 2013, Vol. 29 >> Issue (11): 2354-2360.doi: 10.3866/PKU.WHXB201309161

电化学和新能源 上一篇    下一篇

电解液对全铅单液流电池电极性能的影响

文越华1, 高辰2, 程杰1, 潘军青2, 曹高萍1, 杨裕生1,2   

  1. 1 防化研究院, 北京 100191;
    2 北京化工大学理学院, 北京 100029
  • 收稿日期:2013-06-26 修回日期:2013-09-16 发布日期:2013-10-30
  • 通讯作者: 文越华 E-mail:wen_yuehua@126.com
  • 基金资助:

    国家重点基础研究发展规划(973)(2010CB227201)和北京市先进化学蓄电技术和材料重点实验室(Z121109002812019)资助项目

Effect of Electrolyte on the Performance of Electrodes for an All Lead Flow Battery

WEN Yue-Hua1, GAO Chen2, CHENG Jie1, PAN Jun-Qing2, CAO Gao-Ping1, YANG Yu-Sheng1,2   

  1. 1 Research Institute of Chemical Defence, Beijing 100191, P. R. China;
    2 College of Science, Beijing University of Chemical Technology, Beijing 100029, P. R. China
  • Received:2013-06-26 Revised:2013-09-16 Published:2013-10-30
  • Contact: WEN Yue-Hua E-mail:wen_yuehua@126.com
  • Supported by:

    The project was supported by the National Key Basic Research Program of China (973) (2010CB227201) and Beijing Key Laboratory of Advanced Chemical Energy Storage Technology and Material, China (Z121109002812019).

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摘要：

研究Pb(Ⅱ)和H+离子浓度对全铅单液流电池正、负电极在复合石墨基体上电化学行为的影响.结果表明,PbO2正极和Pb负极的电极过程受电化学和扩散混合控制.Pb(Ⅱ)氧化沉积成PbO2时出现成核环,铅负极成核过电位小,充放电电压差远小于PbO2正极,电池极化主要来自PbO2正极.增加H+浓度有利于降低PbO2正极和Pb负极的极化,但析氧、析氢副反应和腐蚀加重.增大Pb(Ⅱ)浓度有利于抑制析氧,但PbO2正极充电电压升高,充放电电压差增大.Pb(Ⅱ)浓度较低时,充放电过程中PbO2沉积层少许脱落,充电电压进一步降低且更趋平稳.为此,电解液中HBF4浓度以2mol·L-1为宜,Pb(Ⅱ)浓度应在0.9mol·L-1以上.

关键词: 全铅单液流电池, PbO2/Pb2+, Pb2+/Pb, 复合石墨电极, HBF4溶液

Abstract:

The effect of Pb(Ⅱ) and H+ concentrations on the electrochemical behavior of a PbO2 anode and a Pb cathode on a graphite composite was investigated. It is shown that the electrode process is under an electrochemical and diffusion mixed control. When a PbO2 deposit is formed, a nucleation loop occurs. The nucleation overpotential of a Pb cathode is rather small. The difference between charge and discharge potentials of the Pb cathode is much lower than that of the PbO2 anode. This indicates that the polarization in an all lead flow battery is attributed mainly to the PbO2 anode. An increase in H+ concentration is beneficial for a reduction in the polarization; however, side reactions producing oxygen and hydrogen, and corrosion also increase. An increase of Pb(Ⅱ) concentration favors the suppression of oxygen evolution, however, the potential of the PbO2 electrode is increased. This results in an increase in the difference between potentials of the charged and discharged states. When the Pb(Ⅱ) concentration is relatively low, PbO2 deposits shed from the substrate during charge and discharge. As a result, the charge potential is further reduced. Appropriate concentrations of HBF4 and Pb(Ⅱ) were determined to be 2 mol ·L-1 and greater than 0.9 mol·L-1, respectively.

Key words: All lead single flow battery, PbO2/Pb2+, Pb2+/Pb, Graphite composite electrode, Fluoroboric acid solution