((哈爾濱工程大學(xué) 超輕材料與表面技術(shù)教育部重點(diǎn)實(shí)驗(yàn)室，哈爾濱 150001))
摘 要: 采用水熱法合成海膽球形和單相納米線形MnO2，并以X射線衍射、掃描電子顯微鏡、循環(huán)伏安、交流阻抗等方法對(duì)其進(jìn)行測(cè)試。結(jié)果表明：相同反應(yīng)條件下采用不同反應(yīng)物可制備具有不同形貌的MnO2。海膽球形MnO2由單相γ-MnO2構(gòu)成，其直徑在1~10 μm之間；納米線形MnO2由單相α-MnO2構(gòu)成，直徑約為50 nm，長(zhǎng)度大于1 μm。兩種形貌的MnO2在2 mol/L的(NH4)2SO4溶液中具有良好的電容特性，2 mA/cm2放電時(shí)海膽球狀MnO2比容量值為244 F/g, 納米線狀MnO2比容量值為159 F/g。交流阻抗測(cè)試表明，海膽形MnO2作為電極材料，具有更良好的電容性能。
關(guān)鍵字: 納米線；海膽球；MnO2；超級(jí)電容器
（(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
