物理化学学报 >> 2017, Vol. 33 >> Issue (11): 2237-2244.doi: 10.3866/PKU.WHXB201705231

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锂氧电池双功能还原石墨烯-LaFeO3复合纳米催化剂的制备及性能

张晓茹1,许跃峰1,沈守宇1,陈媛1,黄令1,李君涛2,孙世刚1,*()   

  1. 1 固体表面物理化学国家重点实验室,厦门大学化学化工学院化学系,厦门361005
    2 厦门大学能源学院,厦门361005
  • 收稿日期:2017-02-17 发布日期:2017-08-25
  • 通讯作者: 孙世刚 E-mail:sgsun@xmu.edu.cn
  • 基金资助:
    国家自然科学基金(21621091);国家重点研发计划(2016YFB0100202)

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)

摘要:

制备具有氧还原(ORR)与氧释放(OER)双功能催化活性的特殊孔道结构电催化剂是锂氧电池研究的挑战之一。本文以氧化石墨烯、硝酸铁、硝酸镧、柠檬酸为原料,结合溶胶凝胶和水热合成方法,制备出还原氧化石墨烯(RGO)与铁酸镧(LaFeO3)复合的双功能催化剂(RGO-LaFeO3)。X射线衍射(XRD)、傅里叶变换红外(FTIR)光谱和Raman光谱分析结果确认该复合催化剂由纯相钙钛矿结构LaFeO3和还原氧化石墨烯组成,扫描电子显微镜(SEM)观察到LaFeO3纳米颗粒均匀地负载在RGO片层表面。锂氧电池测试结果指出,相对于LaFeO3纳米粒子(NP-LaFeO3),RGO-LaFeO3催化剂具有更好的ORR和OER催化活性,归因于RGO特殊的三维导电多孔结构与LaFeO3纳米粒子的协同催化作用。以RGO-LaFeO3作为阴极催化剂的锂氧电池在限1000 mAh·g-1比容量、100 mA·g-1电流密度条件下,可实现36周稳定的充放电循环,展示出良好的应用前景。

关键词: RGO-LaFeO3, 双功能催化剂, ORR, OER, 锂氧电池, 溶胶凝胶法, 水热法

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