MnO/氮掺杂石墨烯复合正极材料在锂空气电池中的高效催化性能研究  

MnO/Nitrogen-doped graphene composite cathode for high performance lithium oxygen batteries

作　　者：雷鸣[1] 曹勇 林晓东[1] 杨续来 蔡森荣 袁汝明[1] 郑明森[1] 董全峰[1] Ming Lei Yong Cao Xiaodong Lin Xulai Yang Senrong Cai Ruming Yuan Mingsen Zheng Quanfeng Dong(State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China GuoXuan High-Tech Power Energy Co. Ltd., Hefei 230001, China)

机构地区：[1]厦门大学化学化工学院化学系,固体表面国家重点实验室,厦门361005 [2]国轩高科动力能源有限公司,合肥230001

出　　处：《中国科学：化学》2017年第5期663-670,共8页SCIENTIA SINICA Chimica

基　　金：国家重点基础研究发展计划(编号:2015CB251102);国家自然科学基金(编号:U1305246,21321062);国家基础科学人才培养基金(编号:J1310024)资助项目

摘　　要：本文采用水热法制备了MnO/氮掺杂石墨烯复合材料.作为非水锂空气电池的正极催化剂,该复合材料表现出了优异的电化学性能以及循环稳定性.在充放电电流密度为0.05 mA cm^(-2)时,其能量效率高达84.6%,远高于目前文献所报道的非贵金属催化剂的能量效率,也超过了基于贵金属的催化剂.其氧还原反应(ORR)和氧析出反应(OER)的过电势分别仅为0.11和0.41 V.扫描电子显微镜(SEM)和透射电子显微镜(TEM)结果表明,所制备的MnO纳米颗粒能够均匀地分散在氮掺杂石墨烯的表面.密度泛函理论(DFT)计算揭示,MnO(100)面是主要的催化活性面,其理论ORR和OER的过电势分别仅为0.21与0.24 V,充放电电势差为0.45V,与实验结果0.52 V相当.MnO/nitrogen-doped graphene （MnO/NG） composite cathode was fabricated by a facile one-pot method as cathode catalyst for non-aqueous lithium oxygen batteries. It exhibited superior electrochemical performance with higher round-trip efficiency and better cyclic stability. It showed a high round-trip efficiency of 84.6% at the current density of 0.05 mA cm-2 with the discharge and charge overpotentials of0.11 and 0.41 V, respectively. Through scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy, it was confirmed that MnO nanoparticles were homogeneously dispersed on NG surface. The density functional theory calculations demonstrated that the superior electrochemical performance of MnO/NG might be attribute to the exposure of stoichiometric MnO （100） surface, with the ORR and OER overpotential only to be 0.21 and 0.24 V, respectively. The discharging-charging voltage gap is 0.45 V, in good agreement with the experimental value of 0.52 V.

关 键 词：MNO 氮掺杂石墨烯 锂空气电池 

分 类 号：O643.36[理学—物理化学]