LiNi_xMn_2-x_O_4的制备、结构及其电催化性能

Preparation, structure of LiNi_xMn_2-x_O_4 and its electrocatalytic properties

为了制备出高电催化活性的电催化剂,以提高锌空气电池的放电电流密度,采用溶胶-凝胶法制备了尖晶石型电催化剂LiNixMn2-xO4(x=0,0.1,0.2,0.3,0.4,0.5)。通过X射线衍射(XRD)、稳态电压-电流极化曲线等方法,研究了所得样品的结构及其电催化性能。研究结果表明,Ni掺杂可显著提高尖晶石型LiMn2O4氧化物的电催化活性,当x=0.2,热处理温度为750℃,保温8h时,所制备的催化剂具有最佳的电催化活性,用该催化剂制备的空气扩散电极在-0.6V极化电位下的电流密度高达265mA/cm2。

In order to improve discharge current density of zinc-air cells, a series of spinel-type LiNixMn2-xO4（x=0,0.1, 0.2,0.3,0.4,0.5） electrocatalysts were synthesized by sol-gel technology. The samples were characterized by X-ray diffraction （XRD）. Their electrocatalytic performances were evaluated by the polarization curves of gas diffusion electrodes. The measurements of polarization curves indicate that the activities of the spinel-type LiMn2O4 oxide for oxygen evolution could be improved by doping with Ni, and the sample（with x=0.2） sintered for 8h at 750 ℃ exhibits high discharge current density ,as high as 265 mA/cm^2 at -0.6 V （vs. Hg/HgO）.