氧气扩散系数对锂空气电池放电性能的影响  

Influence of oxygen diffusion coefficient on discharge performance of lithium air batteries

作　　者：闫宇星 张珏璇[2] 肖正伟 李付绍 YAN Yu-xing;ZHANG Jue-xuan;XIAO Zheng-wei;LI Fu-shao(College of Chemistry and Environmental Science,Qujing Normal University,Qujing Yunnan 655011,China;College of Teacher Education,Qujing Normal University,Qujing Yunnan 655011,China;Faculty of Metallurgical and Energy Engineering,Kunming University of Science and Technology,Kunming Yunnan 650093,China)

机构地区：[1]曲靖师范学院化学与环境科学学院,云南曲靖655011 [2]曲靖师范学院教师与教育学院,云南曲靖655011 [3]昆明理工大学冶金与能源工程学院,云南昆明650093

出　　处：《电源技术》2018年第11期1717-1719,1723,共4页Chinese Journal of Power Sources

摘　　要：锂空气电池工作过程依赖于氧气的供给,由于电池结构设计等因素的限制,氧气的扩散传输需要跨越结构性屏障。通过分子动力学软件模拟估算了氧分子在PDMS和溶剂中的扩散系数,并针对锂空气电池放电曲线进行了解释。动力学计算表明,在锂空气电池工作过程中,氧气在膜材料中的扩散系数要低于在电解液中的扩散系数,这说明氧气传输量由膜材料控制。此外,对电池放电过程的分析显示,锂空气电池放电效率也与氧气的供应量有关,电极反应位处氧气浓度越高,放电过电位就越低,电池的电流效率就越高。The working of a lithium air battery depends on the supply of oxygen, and the transportation and diffusion ofoxygen need overcome barriers due to the limitations in structural design of the battery. The oxygen diffusioncoefficient in PDMS membrane was estimated by molecular dynamics simulation and the discharge curve of lithiumair battery was explained. Dynamics calculations indicate that during discharging of the air battery, the oxygendiffusion coefficient in PDMS is lower than that in the electrolyte, indicating that the oxygen transportation iscontrolled by the membrane. In addition, by analyzing the discharge process, it is shown that the discharge efficiencyis related to the supply of oxygen. The higher the oxygen concentration at reaction sites in electrode, the lower thedischarge overpotential and the higher the current efficiency.

关 键 词：锂空气电池 分子动力学模拟 氧扩散系数 电流效率 过电位 

分 类 号：TM911[电气工程—电力电子与电力传动]