(1. 中南大學(xué) 冶金與環(huán)境學(xué)院，長沙 410000； 2. 湖南艾華集團股份有限公司，益陽 413000)
摘 要: 基于COMSOL仿真平臺，建立一維電化學(xué)模型，研究放電電流密度、氧氣濃度、氧氣擴散速率以及Li+擴散系數(shù)等因素對電池性能影響。結(jié)果表明：當(dāng)放電電流密度從0.05 mA/cm2增大到0.5 mA/cm2時，鋰空氣電池的放電比容量由1256.4 mA？h/g下降到139.2 mA？h/g；在放電電流密度為0.1mA/cm2條件下，外界氧氣濃度從4.73 mol/m3增加到18.92 mol/m3時，電池比容量從371.2 mA？h/g增加到1274.5 mA？h/g，表明提高外部環(huán)境的氧氣濃度有助于提高電池比容量；氧氣擴散速率為電池反應(yīng)的速度控制步驟。當(dāng)氧氣擴散系數(shù)從3.5×10-10 m2/s 提高到7×10-9 m2/s時，電池的容量從373.0 mA？h/g增加到2352.1 mA？h/g；而提高Li+的擴散系數(shù)對電池的比容量幾乎沒有影響。
關(guān)鍵字: 鋰空氣電池；電流密度；氧氣濃度；擴散系數(shù)；數(shù)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
