花球形貌层状二氧化锰的水热制备及表征

Hydrothermal preparation and characterization of layered manganese dioxide with ball-flower morphology

以KMnO4为锰源,在硫酸酸性介质中,利用水热反应制备了花球形貌δ-MnO2。考察了水热温度、体系酸度和KMnO4起始浓度对反应产物晶相和形貌的影响。采用XRD、SEM和N2吸-脱附等技术对产物进行表征。结果表明,花球形貌δ-MnO2的比表面积为63.9 m^2/g。电流密度为100 mA/g时,δ-MnO2的首次放电比容量达到1494.2 mAh/g。恒流充放电200次后,容量保持率为80.6%。

δ-MnO2 with ball-flower morphology was prepared by hydrothermal reaction with KMnO4 as a manganese source in acid medium of sulfuric acid.The effects of hydrothermal temperature,system acidity and initial concentration of KMnO4 on structure and morphology of products were investigated.The obtained products were characterized by X-ray diffraction,scanning electron microscopy and N2 adsorption-desorption.The result showed thatδ-MnO2 with ball-flower morphology has specific surface area of 63.9 m^2/g.δ-MnO2 exhibits an initial discharge capacity of 1494.2 mAh/g at the current density of 100 mA/g.And the capacity retention reaches 80.6%after 200 cycles.