【摘要】 为了改善空气电极的电催化性能,提高锌空气电池的放电电流密度。采用溶胶-凝胶法制备了锌空气电池用催化剂LiMn2-xCoxO4。通过X射线衍射(XRD)、粒径分布、稳态电流-电压极化曲线等方法,研究了所得催化剂的结构及其电催化性能,并与高温固相反应法所得催化剂的结构与电催化性能作了对比。结果表明,当反应体系的pH值为7~8、温度为80℃时所得凝胶再经600℃下保温处理12h,可以得到具有最高催化活性的催化剂;溶胶-凝胶法合成催化剂的粒径较小,主要集中在1μm~4.5μm的范围内,粒度分布较窄,而高温固相反应法合成催化剂的粒径较大,主要集中在5μm~30μm的范围内,粒度分布较宽;2种方法所得的催化剂具有完全相同的晶态结构;溶胶-凝胶法和高温固相反应法催化剂的空气电极在–0.6V极化电位下的电流密度分别达到250mA/cm2和210mA/cm2,前者比后者的较高。更多还原

【Abstract】 In order to improve the electrocatalytic performance of air electrode and increase discharging current density of zinc-air battery, the catalyst of LiMn2-xCoxO4 was prepared by sol-gel method for zinc-air battery. The structure and electrocatalytic performance of the catalyst were studied by XRD, size distribution and steady current-voltage polarization curve, and compared to the catalyst synthesized by the high temperature solid-state reaction. The research showed that when the pH value of reaction system was 7~8, gelation temperature was 80℃. Insulated at 600℃ for 12 h, the catalyst got the highest catalytic activity. The current density reached 250 mA/cm2 at –0.6 V (vs.Hg/HgO); The particle size (5 μm~30 μm) of the catalyst synthesized by the high temperature solid-state reaction was larger, and size distribution was wider; The particle size (1 μm~4.5 μm) of the catalyst synthesized by sol-gel method was smaller, and size distribution was narrower, The current density of the air electrode made from the catalyst synthesized by sol-gel method and high temperature solid phase reaction at –0.6 V (vs.Hg/HgO) reached 250 mA/cm2 and 210 mA/cm2, respectively, the former was higher than the later.更多还原