放电温度与Li_2O_2充电极化特性关系研究

充电极化过大是制约锂空气电池应用的关键问题之一,这主要源于其放电产物Li2O2低的体相电荷传输能力。本文基于缩短体相电荷传输路径的目的,首次采用控制放电温度的技术降低Li2O2颗粒尺度,研究不同Li2O2的颗粒尺度的充电特性。研究表明,放电温度可以调控Li2O2颗粒特性,高温放电产生的Li2O2倾向在更多的碳基体上形核,颗粒更为细小,可进一步降低充电的电化学反应极化。本研究为降低锂空气电池充电极化提供了一种全新的思路。

Research on the Relationship of Discharging Temperature and Li2O2 Charging Polarization

Large charging polarization, resulting from the poor bulk charge transport ability of discharge product Li2O2, is one of the key issues of Li-air battery, which restricts its application. In this paper, we firstly try to reduce the charging polarization during the first cycle of Li2O2 by methods of controlling discharging temperature since this method can reduce Li2O2 bulk charge transport path. It has been found that, the particle characteristic can be controlled by discharging polarization, respectively. The Li2O2 particles obtained at high temperature are finer since they tend to nucleate on more carbon substrates. Thus, the charging polarization can be further reduced. These results provide a novel method for reducing charging polarization of Li-air battery.