Acta Phys. -Chim. Sin. ›› 2017, Vol. 33 ›› Issue (11): 2237-2244.doi: 10.3866/PKU.WHXB201705231

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Reduced Graphene Oxide-LaFeO3 Composite Nanomaterials as Bifunctional Catalyst for Rechargeable Lithium-Oxygen Batteries

Xiao-Ru ZHANG1,Yue-Feng XU1,Shou-Yu SHEN1,Yuan CHEN1,Ling HUANG1,Jun-Tao LI2,Shi-Gang SUN1,*()   

  1. 1 State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian Province, P. R. China
    2 College of Energy, Xiamen University, Xiamen 361005, Fujian Province, P. R. China
  • Received:2017-02-17 Published:2017-08-25
  • Contact: Shi-Gang SUN E-mail:sgsun@xmu.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(21621091);the National Key Research and Development Program of China(2016YFB0100202)

Abstract:

Development of electrocatalysts is one of the challenges in the development of the lithium-oxygen battery, especially the synthesis of catalysts with special pore structures and excellent bifunctional catalytic performance for both the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER). In this article, a reduced graphene oxide-LaFeO3 (RGO-LaFeO3) nanocomposite electrocatalyst was synthesized by combining sol-gel and hydrothermal methods and using graphene oxide, lanthanum nitrate, ferric nitrate, and citric acid as raw materials. The prepared samples were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, and scanning electron microscopy. The results confirmed that the RGO-LaFeO3 was composed of pure phase LaFeO3 with a perovskite structure and RGO and that the LaFeO3 nanoparticles were loaded uniformly on the RGO layer surface. In comparison with a LaFeO3 nanoparticle (NP-LaFeO3) catalyst, RGO-LaFeO3 exhibited superior activity for both the ORR and the OER when it served as the cathode of a lithium-oxygen battery. The higher catalytic activity of the RGO-LaFeO3 is attributed to the synergistic effect of the special three-dimensional electronic conductive structure of RGO and the intrinsic catalytic property of LaFeO3. It was shown that the lithium-oxygen battery with the RGO-LaFeO3 cathode can be cycled stably up to 36 reversible cycles under conditions of a limit discharge depth of 1000 mAh·g-1 and a 100 mA·g-1 current density for charge-discharge. The study illustrates that the RGO-LaFeO3 bifunctional electrocatalyst is a promising candidate for the cathode in lithium-oxygen batteries.

Key words: RGO-LaFeO3, Bifunctional catalyst, ORR, OER, Li-O2 battery, Sol-gel, Hydrothermal

MSC2000: 

  • O646