生物质炭具有天然的分级多孔结构，是双电层电容器优良的电极材料，但是其电导率低限制了其应用。将具有良好导电性能的石墨烯与生物质炭做成复合材料，可提高超级电容器的性能。采用真空浸渍法将石墨烯负载到生物质炭的表面和孔隙中。石墨烯不仅提高了生物质炭的电导率，而且增加了比表面积。生物质炭/石墨烯复合电极在电流密度为0.5 A/g时，比电容大小为159.74 F/g，比未负载石墨烯的纯生物质炭电极提高了4倍多。充放电循环5 000次，性能无衰减，呈现出良好的稳定性。

Biochar with natural hierarchical porous structure is an ideal electrode material for double layer capacitor.But its low conductivity limits the application.To prepare high performance super capacitor,high conductive graphene is combined with biochar to form biochar/graphene composite material.In this study,graphene is deposited on the surface and into pores of biochar via vacuum impregnation method.The loaded graphene enhances the conductivity as well as the specific surface area of biochar.Biochar/graphene composite electrode exhibits a specific capacitance of 159.74 F·g^-1 under a current density of 0.5 A·g^-1,which is four times larger than that of pure biochar without graphene.The electrode still shows excellent stability without any damping after 5 000 charge-discharge cycles.

芮保珍(1993-),女,硕士研究生,研究方向为生物质炭和石墨烯复合材料,matershu@163.com