((哈尔滨工程大学 超轻材料与表面技术教育部重点实验室，哈尔滨 150001))
摘 要: 采用水热法合成海胆球形和单相纳米线形MnO2，并以X射线衍射、扫描电子显微镜、循环伏安、交流阻抗等方法对其进行测试。结果表明：相同反应条件下采用不同反应物可制备具有不同形貌的MnO2。海胆球形MnO2由单相γ-MnO2构成，其直径在1~10 μm之间；纳米线形MnO2由单相α-MnO2构成，直径约为50 nm，长度大于1 μm。两种形貌的MnO2在2 mol/L的(NH4)2SO4溶液中具有良好的电容特性，2 mA/cm2放电时海胆球状MnO2比容量值为244 F/g, 纳米线状MnO2比容量值为159 F/g。交流阻抗测试表明，海胆形MnO2作为电极材料，具有更良好的电容性能。
关键字: 纳米线；海胆球；MnO2；超级电容器
（(Key Laboratory of Superlight Materials and Surface Technology of Ministry of Education, Harbin Engineering University, Harbin 150001)）
Abstract:Hydrothermal method was used to prepare MnO2 powders with two diverse morphologies of urchin sphere and nanowire. The microstructure and supercapacitor properties of MnO2 powders were characterized by XRD, SEM, CV, AC impedance. The results show that MnO2 powders prepared using different reacted agents have different morphologies under the same condition; the pure γ-MnO2 phase shows urchin sphere morphology with the diameters from 1 to 10 μm, while the pure α-MnO2 shows nanowire morphology with the diameter of 50 nm and the length more than 1 μm. MnO2 powders with two different morphologies have excellent capacitance behaviors in 2 mol/L (NH4)2SO4 solution. The specific capacitance is 244 F/g for urchin sphere-structured MnO2, and 159 F/g for nanowire-structured MnO2 at the current of 2 mA/cm2. The results of AC impedance indicate that urchin sphere-structured MnO2 has better capacitive properties than nanowire-structured MnO2.
Key words: nanowires; urchin sphere; MnO2; supercapacitor
