锂空气电池金属氧化物基空气电极的材料设计及性能研究

项目名称： 锂空气电池金属氧化物基空气电极的材料设计及性能研究

项目编号： No.51272267

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 一般工业技术

项目作者： 吴相伟

作者单位： 中国科学院上海硅酸盐研究所

项目金额： 80万元

中文摘要： 锂空气电池具有最高的理论能量密度，但是目前因氧气在空气电极中扩散受到限制而导致了实际容量有限、倍率性能极差等技术问题，限制了其应用。本项目提出一种以疏油性金属氧化物代替常规碳材料作为空气电极载体。金属氧化物材料具有一定的疏油性、高比表面积、稳定的三维多孔结构，同时还具有一定的催化活性等优点。其疏油性可有效阻止有机电解液淹没空气电极，相比亲油性碳材料更有利于获得"气体扩散电极"， 提高氧气传输能力，并增加空气电极中气固液三相界面反应区域，从而大幅度提高锂空气电池的实际比容量与倍率性能，为将来大功率应用创造条件；其本身所具有的催化活性可有效降低锂空气电池在充放电过程中产生的过电位。项目将系统研究疏油性氧化物的组成、形貌与微观结构对大倍率锂空气电池电化学性能的影响规律及其提高气体输运性能的机理，为动力锂空气电池空气电极材料的研究与应用提供理论基础与借鉴。

中文关键词： 锂空气电池；空气电极；金属氧化物；掺杂；自支撑电极

英文摘要： The lithium-oxygen (Li-O2) battery has recently attracted much attention owing to its extremely high theoretical energy density. However, two major challenges including limited practical capacity, bad power characteristic induced by the low oxygen diffusion rate in the air electrode limit the practical application of the Li-O2 batteries. In this project, the hydrophilic metal oxides are proposed as the alterative support of conventional carbon material for air electrode. The metal oxides, have many advantages, such as high chemical and electrochemical stability, stable three-dimensional structure, catalytic activity, especially the higher polarity than the carbon materials expressed as higher hydrophilic property. The hydrophilic property could help to eliminate the electrolyte flooding the electrode, enhance the oxygen diffusion ability, increase the three-phase-interface, and thus improve the capacity and rate capability. The catalytic activity of the metal oxides could be benificial to decrease the overpotential of Li-O2 cell during the charge-discharge process. The mechanism of improved gas diffusion and effect of metal oxides' microstructure on electrochemical performance will be investigated. Research and application of high-performance Li-O2 cell will benefit from the implementation of this project.

英文关键词： Lithium-oxygen battery；Air electrode；Metal-Oxides；Doping；Free-standing cathode