Se掺杂介孔二氧化锰的合成及电化学性能研究

Synthesis and Discharge Capability of Se-doped Mesoporous MnO_2

以介孔硅SBA-15为模板,硝酸锰作锰源,采用液相浸渍法,合成了介孔二氧化锰;在合成的过程中掺入硒粉,制备硒掺杂的介孔二氧化锰。采用XRD、SEM、TEM和BET等分析手段对样品的形貌和结构进行表征。结果表明:所合成的介孔二氧化锰与SBA-15具有相似的形貌和有序介孔结构;掺杂硒后,介孔二氧化锰的形貌和结构都没有明显的变化。为了研究样品的电化学性能,在9 mol/L KOH溶液中,250 mA/g的电流密度下放电。结果表明:介孔二氧化锰的放电容量达到344.26 mAh/g,比EMD增加119.7%。掺杂硒后,介孔二氧化锰的放电容量增大了,当掺硒量为5%时,介孔二氧化锰的放电容量最大,达到430.25 mAh/g,比EMD增加174.6%。

We use mesoporous silicon SBA- 15 as a template and manganese nitrate solution[ Mn（ NO3）2, 50wt%]as the manganese source to synthesis mesoporous MnO2 with uniform nanorod morphology,and use Se doping technique to improve its discharge performance. XRD, nitrogen adsorption analysis, SEM and TEM are used for the structural characterization. The electrochemical properties of the as - prepared MnO2 were studied using alkaline Zn/MnO2 batteries in 9 mol/L KOH electrolyte. Under the discharge constant currents of 250 mA/g, the discharge capacity of the mesoporous MnO2 nanorods is 344.26 mAh/g, while the discharge capacity of 5% Se-doped mesoporous MnO2 nanorods is 430.25 mAh/g. Compared to the commercial electrolytic manganese dioxide（EMD）, the discharge capacity of the mesoporous M nO2 nanorods and 5% Se-doped mesoporous MnO2 nanorods is increased by 119.7 % and 174.6%, restively.