化工学报 ›› 2014, Vol. 65 ›› Issue (7): 2843-2848.DOI: 10.3969/j.issn.0438-1157.2014.07.046

• 能源和环境工程 • 上一篇    下一篇

锌-空气电池电解液Zn2+浓度对析氢过程的影响

马洪运, 范永生, 王保国   

  1. 清华大学化学工程系, 化学工程联合国家重点实验室, 北京 100084
  • 收稿日期:2014-04-02 修回日期:2014-04-14 出版日期:2014-07-05 发布日期:2014-07-05
  • 通讯作者: 王保国
  • 基金资助:

    国家自然科学基金项目(21276134);国家高技术研究发展计划项目(2012AA051203)。

Effects of Zn2+ concentration upon hydrogen evolution reaction for zinc-air battery

MA Hongyun, FAN Yongsheng, WANG Baoguo   

  1. State Key Laboratory of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
  • Received:2014-04-02 Revised:2014-04-14 Online:2014-07-05 Published:2014-07-05
  • Supported by:

    supported by the National Natural Science Foundation of China(21276134) and the National High Technology Research and Development Program of China (2012AA051203).

摘要: 水溶液体系的二次金属-空气电池通常具有安全环保的特点,但是充电过程中仍然存在析氢副反应的安全隐患。使用线性电势扫描方法、Tafel极化曲线及极限扩散电流密度参数定量分析了二次锌-空气电池体系电解液中Zn2+浓度对析氢反应过程的影响。结果表明,随着电解液中Zn2+浓度的提高,析氢过电势逐渐增大,Zn2+浓度在6 mol·L-1 KOH溶液中达到0.4 mol·L-1时,析氢过电势超过2.42 V,析氢过电势比空白溶液提高1.2 V,并且Tafel极化曲线的截距超过1.5 V,析氢电势达到超高过电势范围。此外,由Zn2+提供的极限扩散电流密度提高至8.9 A·cm-2,所对应的过电势提高700 mV。研究结果对于确立二次锌-空气电池极限充电范围提供定量依据,对电池安全平稳运行具有重要价值。

关键词: 析氢过程, 锌-空气电池, 线性电势扫描, Tafel极化曲线, 极限扩散电流密度

Abstract: Owing to the usage of water solution, the secondary metal-air batteries could be excellent for energy storage systems with outstanding advantages in high safety and environmental friendliness. However, the side reaction of hydrogen evolution in the water solution system is the potential hazard for the operation of batteries. In this study, the effects of Zn2+ concentration on hydrogen evolution reaction were investigated with the methods of linear sweep voltammetry, Tafel polarization curves and parameters of limiting diffusion current density for the zinc-air battery. The results showed that the overvoltage of hydrogen evolution reaction reached 2.42 V and the overpotential was 1.2 V higher than that in the blank solution when the concentration of Zn2+ in 6 mol·L-1 KOH solution was 0.4 mol·L-1. The intercept of the Tafel equation was more than 1.5 V, which suggests that the hydrogen evolution reaction for the solution containing 0.4 mol·L-1 Zn2+ reaches the super-overpotential range. The limiting diffusion current density reached 8.9 A·cm-2 and the overpotential was raised by 700 mV. These data are urgently needed for the subsequent operating conditions of the secondary zinc-air batteries and play an important role in the steady and safe operation for the battery system.

Key words: hydrogen evolution reaction, zinc-air battery, linear sweep voltammetry, Tafel polarization curves, limiting diffusion current density

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