熔盐法制备二氧化锰及放电性能研究

Synthesis of MnO_2 Powder by Molten Salt Method and Discharge Property

以金属锰粉和高锰酸钾为原料,采用熔盐法在KCl-NaCl体系和NaNO3体系中成功地合成了二氧化锰(MnO2)电极材料。利用X射线衍射(XRD)和扫描电子显微镜(SEM)对样品的结构与形貌进行了表征,结果表明:合成样品为单斜晶系产物,粉末样品为片状结构。在c(KOH)=9mol/L电解液中采用三电极体系对样品进行恒电流放电和循环伏安测试,结果显示该材料在电流密度为250 mA/g时,单电极放电比容量达到251.3 mAh/g,是电解二氧化锰(EMD)的2.5倍。

MnO2 electrode materials are prepared by molten salt synthesis method,using metal manganese powder and potassium hypermanganate as raw materials as well as KCl-NaCl eutectic systems and NaNO3 as fluxes.The structure and morphology of MnO2 powder are investigated by X-ray diffraction（XRD）and scanning electric microscope（SEM）,respectively.The XRD results indicate that the prepared samples were monoclinic system,and the synthesized samples are shown in SEM.Furthermore,the constant current discharge and cyclic voltampere of MnO2 samples were measured by three-electrode system in 9 mol/L KOH solution,and the results show that when current density of samples are 250 mA/g,the single electrode of discharge specific capacitance reaches up to 251.3 mAh/g,which is two and an half times of that of electrolysis manganese dioxide.