构建CEI膜提升氯化镍正极热电池放电性能

Improving discharge performance of thermal battery with nickel chloride cathode by constructing CEI film

利用碳材料在正极与隔膜之间构筑电化学界面(CEI)薄膜,避免正极材料与隔膜材料的直接接触,通过能量散射光谱(EDS)对放电后隔膜材料表面元素进行表征分析。结果表明:多壁碳纳米管构造的CEI膜的单体电池在100 mA/cm^(2)的小电流密度放电的电性能明显提升,添加CEI-1粉料的3#电池较不添加CEI膜的1#电池放电容量有效提升40%以上,以单体电压2.0 V为截止电压计算,放电时间824 s,放电比容量达到994 A·s/g,正极材料的利用率达到89%,正极材料的有效容量得到充分利用。因此,利用多壁碳纳米管材料在正极与隔膜之间构筑CEI薄膜可以有效防止正极与隔膜材料的互熔,避免电池后期发生短路。

A electrochemical interface(CEI)thin film between the cathode and the separator was constructed by using carbon materials to avoid the direct contact between the cathode and separator materials.The elements on the surface of the separator material after discharge were characterized and analyzed by using energy dispersive spectroscopy(EDS).The results show that the electrical performance of the cell with multi walled carbon nanotubes constructed CEI film improves significantly at a low current density of 100 mA/cm^(2).Compared to 1#batteries without CEI film,the discharge capacity of 3#batteries with CEI-1 powder effectively increases by more than 40%.With a cut-off voltage of 2.0 V for the cell,the discharge time is 824 s,the discharge specific capacity reaches 994 A·s/g,and the utilization rate of the cathode material reaches 89%.The effective capacity of the cathode material is fully utilized.Therefore,using multi walled carbon nanotube materials to construct CEI thin films between the cathode and separator can effectively prevent the mutual melting of the cathode and separator materials,and avoid the short circuit in the later stage of the battery.