(1. 中南大学 冶金与环境学院，长沙 410000； 2. 湖南艾华集团股份有限公司，益阳 413000)
摘 要: 基于COMSOL仿真平台，建立一维电化学模型，研究放电电流密度、氧气浓度、氧气扩散速率以及Li+扩散系数等因素对电池性能影响。结果表明：当放电电流密度从0.05 mA/cm2增大到0.5 mA/cm2时，锂空气电池的放电比容量由1256.4 mA？h/g下降到139.2 mA？h/g；在放电电流密度为0.1mA/cm2条件下，外界氧气浓度从4.73 mol/m3增加到18.92 mol/m3时，电池比容量从371.2 mA？h/g增加到1274.5 mA？h/g，表明提高外部环境的氧气浓度有助于提高电池比容量；氧气扩散速率为电池反应的速度控制步骤。当氧气扩散系数从3.5×10-10 m2/s 提高到7×10-9 m2/s时，电池的容量从373.0 mA？h/g增加到2352.1 mA？h/g；而提高Li+的扩散系数对电池的比容量几乎没有影响。
关键字: 锂空气电池；电流密度；氧气浓度；扩散系数；数值仿真
（1. School of Metallurgy and Environment, Central South University, Changsha 410000, China; 2. Aihua Group Co., Ltd., Yiyang 413000, China）
Abstract:Based on COMSOL simulation platform, a one-dimensional electrochemical model was established to study the effect of applied current density, oxygen concentration, diffusion of oxygen and lithium-ion on the performance of lithium air battery. The results show that the specific capacity reduces from 1256.4 mA？h/g to 139.2 mA？h/g with the applied current density increasing from 0.05 mA/cm2 to 0.5 mA/cm2; and the specific capacity is improved from 371.2 mA？h/g to 1274.5 mA？h/g with the oxygen concentration increasing from 4.73 mol/m3 to 18.92 mol/m3 when the applied current is set as 0.1mA/cm2. It is suggested that the specific capacity can be improved by increasing the oxygen concentration. The diffusion rate of oxygen is the rate-determining step during the discharge process. When the diffusion coefficient of oxygen increases from 3.5×10-10 m2/s to 7×10-9 m2/s, the specific capacity is improved from 373.0 mA？h/g to 2352.1 mA？h/g. The diffusion coefficient of Li+ has almost no effect on the specific capacity.
Key words: lithium air battery; current density; oxygen concentration; diffusion coefficient; numerical simulation
