α-MnO2@ZAC活性炭复合材料的制备及其电化学性能研究

Preparation of α-MnO2@ZAC Activated Carbon Composite and Its Electrochemical Properties

关键词:  二氧化锰  活性炭  复合材料  超级电容器  电化学性能

Key Words:manganese dioxide  activated carbon  composite materials  supercapacitors  electrochemical properties

摘要:本研究以蔗渣为原料，ZnCl₂活化制备的活性炭（ZAC）作为导电基底，采用水热法将一维α-MnO₂沉积到ZAC上，研究α-MnO₂沉积量对复合材料电化学性能的影响。X射线光电子能谱仪（XPS）和元素分析仪（EA）结果显示，ZAC中成功掺杂了Mn元素，随着ZAC占比增加，复合材料中负载的Mn含量从29.78%减至5.57%。X射线衍射仪（XRD）和拉曼光谱仪分析表明，ZAC表面水热沉积了以一维隧道结构的纳米棒状为主要晶相的α-MnO₂，制备了具有石墨结构的复合材料，其中，MnZAC-4具有最大比电容327 F/g，在循环1000次后比电容仍能保持88.2%，且电化学阻抗较小。此外，根据透射电子显微镜（TEM）、XRD和拉曼光谱结果探讨了在ZAC上沉积α-MnO₂制备α-MnO₂@ZAC复合材料的机理。

Abstract:In this study， one-dimensional α-MnO₂ was deposited on the surface of ZAC by hydrothermal method with bagasse as raw material and activated carbon （ZAC） prepared by ZnCl₂ activation method as the conductive substrate， and the effects of different deposits of α-MnO₂ on the electrochemical performance of composite materials were studied. The results of XPS and EA showed that Mn was successfully doped on the surface of ZAC， and the content of Mn doped was decreased from 29.78% to 5.57% with the increase of ZAC proportion in composite. The results of XRD and Raman showed that the surface of ZAC was hydrothermally deposited with one-dimensional tunnel structure nanorod-shaped α-MnO₂，and a series of composite materials with graphite structure were prepared. Among them， MnZAC-4 had the largest specific capacitance of 327 F/g， its specific capacitance could still maintain 88.2% after 1000 cycles， and the electrochemical impedance was small. In addition， according to the results of TEM， XRD and Raman， the preparation mechanism of α-MnO₂@ZAC composites by hydrothermal deposition method was discussed.