线团形貌层状二氧化锰的制备及其在不对称电化学电容器中的应用(英文)  

Preparation of Clew-like MnO_2 with Layered Structure as High-performance Asymmetric Electrochemical Capacitor Electrodes

作　　者：邓玲娟[1] 古元梓[1] 徐维霞[1] 张知侠[1] 

机构地区：[1]咸阳师范学院化学与化工学院,咸阳712000

出　　处：《应用化学》2014年第1期76-83,共8页Chinese Journal of Applied Chemistry

基　　金：Supported by the Special Scientific Research Funding of Xianyang Normal University(12XSYK027,12XSYK029)~~

摘　　要：将无定型MnO：在1mo]／LNaOH水溶液中150oC水热处理12h后，得到了具有线团形貌的层状二氧化锰。利用XRD、SEM和低温N：吸-脱附等手段对样品的形貌和结构进行了表征。采用循环伏安、恒流充放电以及交流阻抗技术对样品的电化学性质进行了研究。研究结果表明，在三电极体系中，线团状MnO：在0～1．0V（珊．SCE）的电压范围内具有较好的电容性质，其质量比电容为154F／g。利用线团状MnO：为正极，石墨烯为负极以及1mol／LNa~SO。水溶液为电解液组装了不对称型的电化学电容器。电化学测试表明，该电容器可在0—1．8V的电压范围内可逆循环，其能量密度为21．6W·h／kg，远远高于基于线团状MnO：（4．86W·h／kg）和石墨烯（4．3W·h／kg）的对称型电容器。Clew-like MnO2 （ CMnO2 ） with a specific capacitance of 154 F/g within a potential window of 0 - 1.0 V vs saturated calomel electrode has been synthesized by hydrothermally treating the precursor of as synthesized MnO2 in a solution of 1 mol/L NaOH at 150 ℃ for 12 h. The morphology and structure of the obtained material were examined by XRD, SEM and N2 adsorption-desorption. The capacitive properties were characterized by cyclic voltammetry, galvanostatic charge-discharge and electrochemical impedance spectroscopies. An asymmetrical electrochemical capacitor（EC） was assembled using CMnO2 as the positive electrode and graphene（GR） as the negative electrode, respectively. The asymmetrical EC can cycle reversibly in a cell potential of 0 - 1.8 V and gives a high energy densi- ty of 21.6 W.h/kg, which is much higher than those of symmetrical ECs based on CMnO2 （4. 86 W h/kg） and GR （4.3 W. h/kg）. Moreover, the asymmetrical EC presents a high power density （9 kW/kg at 8. 1 W. h/kg） and excellent cycling performance of 83% retention after 1000 cycles.

关 键 词：不对称电化学电容器 二氧化锰 石墨烯 能量密度 循环稳定性 

分 类 号：O646[理学—物理化学]