高比表面积碳化钨制备及其在锂空气电池中电催化性能研究

Preparation of tungsten carbide with high specific surface area and its electrocatalytic performance in lithium-air batteries

锂空气电池具有高能量密度和良好的发展前景,但其循环性能仍不能满足使用要求,而空气电极侧(即正极)的电化学反应对电池的循环可逆性具有显著影响,正极催化剂的引入可以显著改善电池的循环性能。以高比表面积的石墨相氮化碳介孔材料作为模板和碳源,以六氯化钨为钨源,通过高温反应制备具有较高比表面积的碳化钨材料,并以该碳化钨作为锂空气电池的正极催化剂。利用透射电子显微镜(TEM)、X射线衍射(XRD)、物理吸附等对合成的样品进行表征,结果表明制备的样品为碳化钨材料,并且具有较高的比表面积。采用电化学测试方法研究了碳化钨材料在锂空气电池中的电催化效果,结果表明该碳化钨材料在锂空气电池中具有良好的电催化性能,电池可以保持较长时间的稳定循环状态。

Due to the high energy density,lithium air battery is a promising rechargeable battery,while the cycling performance does not meet the demand.However,the electrochemical reaction on the air electrode(cathode)side had a significant impact on the circulation reversibility of battery,the introduction of the electrocatalyst in cathode could obviously improve the cycling performance of battery.The tungsten carbide with high specific surface area was synthesized to be the cathode catalyst of lithi um air battery,using the graphitic carbon nitride material with an ordered pore structure and high specific surface area as car bon source and template,and using tungsten hexachloride as the source of tungsten in high temperature.The sample was cha racterized by TEM,XRD and physical adsorption tests.Results showed that the sample had tungsten carbide phase and a higher specific surface area.The electrocatalytic effect of tungsten carbide material in lithium air battery was studied by electrochemi cal test.The results showed that the tungsten carbide material had good electrocatalytic performance in the lithium air battery,and the battery could maintain a longer stable circulation state.