物理化学学报 >> 2012, Vol. 28 >> Issue (12): 2893-2897.doi: 10.3866/PKU.WHXB201210101

电化学和新能源 上一篇    下一篇

Sn0.9Mg0.1P2O7的中温离子导电性

王洪涛, 孙林, 陈继堂, 罗春华   

  1. 阜阳师范学院化学化工学院, 安徽 阜阳 236041
  • 收稿日期:2012-07-16 修回日期:2012-10-09 发布日期:2012-11-14
  • 通讯作者: 王洪涛 E-mail:hongtaoking3@126.com
  • 基金资助:

    国家自然科学基金(50903018)资助项目

Ionic Conduction in Sn0.9Mg0.1P2O7 at Intermediate Temperatures

WANG Hong-Tao, SUN Lin, CHEN Ji-Tang, LUO Chun-Hua   

  1. College of Chemistry and Chemical Engineering, Fuyang Teachers College, Fuyang 236041, Anhui Province, P. R. China
  • Received:2012-07-16 Revised:2012-10-09 Published:2012-11-14
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (50903018).

摘要:

采用固相法合成了Sn0.9Mg0.1P2O7, 用扫描电子显微镜(SEM)、X射线衍射(XRD)测试方法对样品进行了表征. 粉末XRD结果表明, 该样品为单一立方相SnP2O7结构. 采用多种电化学方法研究了样品在中温范围内(323-523 K)质子和氧离子导电性. 样品在湿润氢气气氛中423 K下, 电导率达到最大值5.04×10-2 S·cm-1. 该样品在氢气气氛中的离子、质子、氧离子和电子迁移数(Nt)分别为0.95-1.00、0.84-0.96、0.04-0.10和0.00-0.05, 该样品在氢气气氛中几乎是一个纯离子导体, 其中, 质子导电为主, 同时具有一定的氧离子导电和少量的电子导电. 以该样品为燃料电池固体电解质, 组装氢气/空气燃料电池, 在398、423和448 K时最大输出功率密度分别为18.7、27.7和33.9 mW×cm-2.

关键词: Sn0.9Mg0.1P2O7, 离子导电, 电解质, 电导率, 浓差电池, 燃料电池

Abstract:

Sn0.9Mg0.1P2O7 was synthesized in a solid state reaction and characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The XRD pattern indicated that the sample exhibited a single cubic phase. The protonic and oxide-ionic conduction were investigated using various electrochemical methods including AC impedance spectroscopy and gas concentration cells at intermediate temperatures (323-523 K). The highest conductivity observed was 5.04×10-2 S·cm-1 in a wet H2 atmosphere at 423 K. The ionic, protonic, oxide-ionic, and electronic transport numbers (Nt) were 0.95-1.00, 0.84-0.96, 0.04-0.10, 0.00-0.05, respectively, in a wet hydrogen atmosphere. The results indicate that Sn0.9Mg0.1P2O7 is an almost pure ionic conductor, has dominant protonic conduction, some limited oxide-ionic conduction, but little electronic conduction. A H2/air fuel cell using Sn0.9Mg0.1P2O7 as the electrolyte (thickness: 1.5 mm) generated maximum power densities of 18.7 mW·cm-2 at 398 K, 27.7 mW·cm-2 at 423 K, and 33.9 mW·cm-2 at 448 K.

Key words: Sn0.9Mg0.1P2O7, Ionic conduction, Electrolyte, Conductivity, Concentration cell, Fuel cell

MSC2000: 

  • O646