MnO_(2)-rGO/竹纤维素基炭气凝胶的制备及其在超级电容器中的应用

Preparation of MnO_(2)-rGO/bamboo cellulose based carbon aerogel and its application in supercapacitors

研究以竹浆纤维为原料,在氢氧化钠和尿素溶解体系中加入氧化石墨烯,经过凝胶、热解制备还原氧化石墨烯(rGO)/竹纤维素基炭气凝胶。以此作为导电基质,采用水热法负载δ-MnO_(2)纳米片,研究了MnO_(2)负载量对复合材料的电化学性能影响,探讨了复合材料的储能机制。结果显示,随着MnO_(2)负载量的增加,复合材料的电化学性能呈先提高后降低的趋势。当初始参与反应的KMnO_(4)含量为0.005 mol时,复合材料比电容可达330 F/g。将其作为正极材料组装的非对称超级电容器在0.5 A/g的电流密度下,比电容高达68.8 F/g;在功率密度为163 W/kg时,能量密度高达16.2 W•h/kg;在2 A/g电流密度下循环8000次后仍能保持94%的初始容量。

Reduced graphene oxide(rGO)/bamboo cellulose based carbon aerogel was prepared after gel and pyrolysis by adding GO in sodium hydroxide and urea solution system.Then,theδ-MnO_(2) nanosheets were deposited on this conductive substrate by hydrothermal method.The effect of MnO_(2) deposition content on the electrochemical properties of the composites and the energy storage mechanism of the composites were studied.The results show that the electrochemical properties of the composites are firstly improved and then decreased with increasing MnO_(2) deposition amount.When 0.005 mol KMnO_(4) is added,the specific capacitance of the composite material is 330 F/g.In addition,the asymmetric supercapacitor exhibits a high specific capacitance of 68.8 F/g at 0.5 A/g,and reveals a high energy density of 16.2 W•h/kg at a power density of 163 W/kg.It retains 94%of the initial specific capacitance after 8000 cycles at 2 A/g.