【摘要】 在冰浴条件下,以KMn O4、KOH和Mn Cl2为反应物,采用液相化学共沉淀法制备了层状δ-MnO₂宿主,然后以KOH为嵌入离子源,采用水热沉淀法,制备了纳米K-MnO₂嵌入化合物.分别采用X-射线衍射光谱和扫描电子显微镜等物理方法对试样的晶体结构和表面形貌进行表征;用循环伏安、恒流充放电和交流阻抗等电化学方法研究其电化学性能.结果表明,纳米K-MnO₂嵌入化合物在1 mol·L-1的KOH、Na OH和Li OH电解液中发生了相互协同的氧化-还原反应和嵌入-脱嵌反应,在相同的扫描速率或电流密度下比电容的大小关系分别为KOH>Na OH>Li OH,在600次循环充放电中展现出了良好的循环稳定性,意味着这种嵌入化合物K-MnO₂是一种很有前途的水系混合超级电容器的正极材料.更多还原

【Abstract】 In this paper,layered δ-MnO₂ host was synthesized with liquid chemical coprecipitation method by using KMn O4,KOH and Mn Cl2 reactants at 0 ℃. Nanostructured K-MnO₂ intercalation compound was prepared by hydrothermal method treated the mixture of δ-MnO₂ as host and KOH as intercalation ion scourse at 180 ℃ for 2 day. Xray diffraction,scanning electron microscopy were used to investigate crystal structure,morphology of the K-MnO₂ intercalation compounds,respectively. The electrochemical properties were evaluated by cyclic voltammetry,galvanostatic charge / discharge and electrochemical impedance spectroscopy,etc. The results show that nanostructured K-MnO₂ intercalation compound presents the synergistic effects of oxidation-reduction reaction and insertion-deinsertion reaction in 1 mol·L- 1KOH,Na OH and Li OH electrolyte,and the specific capacitance of K-MnO₂ is in the order of KOH > Na OH > Li OH at same scan rate or current density,respectively. Exhibiting excellent 600-cycle charge-discharge in 1 mol ·L- 1KOH electrolyte,which indicate that the as-prepared K-MnO₂ intercalation compound would be as a promising cathode materials for aqueous hybrid supercapacitors.更多还原