LaMg2Ni2.7Co2.1Mn2.7Cu1.5 滴涂TiO2复合电极的制备及电化学性能

Preparation and Electrochemical Property of Combined Electrode of LaMg2Ni2.7Co2.1Mn2.7Cu1.5 Coated with TiO2

摘要:

采用共沉淀还原扩散法制备AB3型储氢合金LaMg2Ni2.7Co2.1Mn2.7Cu1.5，水热法制备TiO2光催化剂粉体，表面滴涂法制备TiO2/LaMg2Ni2.7Co2.1Mn2.7Cu1.5光催化剂复合电极，并用XRD对合金和光催化剂结构进行分析，在电池测试仪上对复合电极在有、无光照条件下的电化学性能进行测试。结果表明，在无光照条件下复合电极的活化性能和最大放电容量较原合金电极性能有所下降，合金充放电的循环稳定性能有提高。光照条件下，表面滴涂20%的TiO2复合电极的电化学性能比无光照时大幅提高，且最大放电容量比未涂覆的原合金电极提高25 mA?h?g-1。说明TiO2光催化剂通过表面滴涂方式对储氢合金修饰效果较好。

Abstract:

LaMg2Ni2.7Co2.1Mn2.7Cu1.5 hydrogen storage alloy was synthesized by the method of co-precipitation and reduction diffusion, and TiO2 powder by hydrothermal method, then the alloy was coated with TiO2 powder to prepare composite electrode. The structures of the hydrogen storage alloy and TiO2 powder were characterized by X-ray diffraction. The electrochemical performances of composite electrode were tested by battery tester under two different conditions. In one condition, the electrode was kept in a dark box. In another condition, the electrode was kept under radiation of a ultraviolet lamp. The results show that in dark box the activation performance and maximum discharge capacity of composite electrode are not as good as that of original alloy electrode that is not coated with TiO2, but the cyclic stability becomes better. In light condition, the electrochemical performances of the composite electrode, including activation performance, maximum discharge capacity and cyclic stability, become better than that of original alloy electrode. For example, the maximum discharge capacity of composite electrode (coated with 20% TiO2) increases 25mA?h?g-1 compared with original alloy electrode. They are also better than that in dark box. The results of this paper illustrate that combination of LaMg2Ni2.7Co2.1Mn2.7Cu1.5 hydrogen storage alloy with TiO2 by surface coating method is effective to improve electrochemical performances of the alloy.