摘要
以自制活性炭(AC)为载体,(NH4)2S2O8为氧化剂、MnSO4为还原剂和锰源、(NH4)2SO4为模板试剂,通过原位水热沉积法制备了α-MnO2/AC系列复合电极材料.分别采用X射线衍射、扫描电子显微镜、N2吸附/脱附等方法对试样的晶型结构、形貌、比表面积和孔结构进行了表征;用循环伏安、恒流充放电和交流阻抗等电化学方法研究了材料的电化学性质.结果表明,在MnSO4浓度为0.075mol·L-1的水热条件下,获得了薄层晶状α-MnO2/AC复合材料.在电流密度为3mA·cm-2时,该材料电化学性能优异,比电容为374.5F·g-1,较沉积前AC的252.7F·g-1有显著提高,增幅为48.2%;α-MnO2/AC复合电极有良好的充放电特性和循环稳定性,经1000次恒流充放电测试,容量保持率达到95%。
The composite electrode materials of α-MnO2/activated carbon（α-MnO2/AC） were prepared by in-situ hydrothermal deposition using ammonium persulfate as oxidants,manganese sulfate as precursors,ammonium sulfate as templates and self-made activated carbon as supports.X-ray diffraction,scanning electron microscopy and nitrogen adsorption-desorption at 77 K were used to investigate the crystal structure,morphology,specific surface area and porosity of the composites,respectively.Their electrochemical properties were evaluated by cyclic voltammetry,galvanostatic charge-discharge and electrochemical impedance spectroscopy.The results showed that crystalline α-MnO2 was well deposited on the AC to produce thin layer crystal α-MnO2/AC composite material at the optimal MnSO4 concentration of 0.075 mol·L^-1 in the synthetic process.The specific capacitance of the composite could be as high as 374.5 F·g^-1,48.2% higher than that of pure AC electrode.The α-MnO2/AC composite electrode had high stability and the capacity retention was of 95% after a 1000-cycle charge-discharge.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2010年第15期1473-1480,共8页
Acta Chimica Sinica
基金
国家"863"计划(No2008AA06Z329)
国家"973"计划(No2007CB209700)资助项目
关键词
原位水热沉积法
活性炭
α-MnO2
电极材料
电化学电容器
in-situ hydrothermal deposition
activated carbon
α-MnO2
electrode material
electrochemical c apacitors
