Acta Phys. -Chim. Sin. ›› 2012, Vol. 28 ›› Issue (12): 2893-2897.doi: 10.3866/PKU.WHXB201210101

• ELECTROCHEMISTRY AND NEW ENERGY • Previous Articles     Next Articles

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).

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