匹配离子液体电解液的氮掺杂石墨烯的制备与电容性能

Preparation and capacitive properties of nitrogen-doped graphene aerogels compatible with ionic liquid electrolyte

以廉价的磷酸胍、碳酸胍和盐酸胍为氮源,采用简便的水热法制备了氮掺杂石墨烯气凝胶.这些气凝胶具有多级孔非晶态无序结构.其中,以盐酸胍为掺杂剂所制备的氮掺杂石墨烯气凝胶(HRGA)具有更高的氮含量(9.7 at%)、更大的比表面积(257.6 m^(2)g^(-1))以及更大的电导率(11.2 S cm^(-1)).以离子液体为电解液,HRGA作为对称型超级电容器的电极材料,在电流密度为1 A g^(-1)时的比电容为176 F g^(-1),在功率密度为875 W kg^(-1)时的能量密度高达70 Wh kg^(-1).氮掺杂石墨烯气凝胶为开发高性能储能器件提供了潜在的电极材料.

Nitrogen-doped graphene aerogels for high performance supercapacitors were synthesized using guanidine phosphate,guanidine carbonate and guanidine hydrochloride as the nitrogen source by a facile and cost-effective hydrothermal method.X-ray diffraction,scanning electron microscopy,and high-resolution transmission electron microscopy characterizations and nitrogen adsorption/desorption analysis indicate that these nitrogen doped graphene aerogels have poorly ordering and hierarchical porous structures.Especially,the nitrogen-doped graphene aerogel(HRGA)prepared using guanidine hydrochloride as the nitrogen source possesses a richer nitrogen content(9.7 at%),higher conductivity(11.2 S cm^(-1)),and larger specific surface area(257.6 m~2g^(-1)).Thus HRGA delivers a large specific capacitance of 176 F g^(-1)at a current density of 1 A g^(-1)and an energy density of 70 Wh kg^(-1)at a power density of0.875 k W kg^(-1).The nitrogen-doped graphene aerogels with enhanced electrochemical performance provide a huge application potential in the energy storage field.