多孔氮掺杂石墨烯/MnO2的制备及其电化学性能

Preparation and Electrochemical Performance of Porous N-doped Graphene/MnO2

用双氧水造孔得到多孔氧化石墨,以尿素为氮源,通过水热法得到了多孔氮掺杂石墨烯(HNG)与MnO2的复合物HNG/MnO2。结果表明:HNG/MnO2在0. 5 A/g电流密度下的比电容可以达到246 F/g,当电流密度达10 A/g,比电容为172 F/g,可以保留70%的比电容。将HNG/MnO2作为正极与石墨烯水凝胶负极组装的非对称超级电容器,在0. 5 A/g可以贡献71 F/g的比电容,当电流升至5 A/g仍可有43 F/g的比电容,保持率为62%。此外,非对称超级电容器在5 A/g的电流密度下,稳定循环3000圈后仍可保留90. 8%的初始容量。

Porous graphite oxide was acquired by H2O2 pore-forming,and then the composite of porous N-doped graphene( HNG)/MnO2 was synthesized using urea as nitrogen source by hydrothermal method. The results show that the specific capacitance of HNG/MnO2 can reach 246 F/g at a current density of 0. 5 A/g,and the specific capacitance of 172 F/g remains at 10 A/g with the specific capacitance retention rate of 70%. The asymmetric supercapacitor assembled by using HNG/MnO2 as the cathode and graphene hydrogel as the anode can contribute a specific capacitance of 71 F/g at 0. 5 A/g,and the specific capacitance of 43 F/g can be obtained when the current density rises to 5 A/g with the retention rate of 62%. In addition,the asymmetric supercapacitor can keep 90. 8% of its initial capacitance after 3000 charge/discharge cycles at 5 A/g.