三维筋撑石墨烯负载氧化锰的超级电容器

石墨烯基超级电容器，其功率密度较高，但能量密度受限。开发以三维石墨烯材料为载体的复合型赝电容多孔电极，是解决方案之一。本文采用铵盐辅助化学发泡法，制备了三维筋撑石墨烯泡沫体（SG）；以SG为载体，采用水热还原法在其表面生长二氧化锰（MnO₂）纳米棒阵列，从而构建了MnO₂/SG自支撑多孔材料。利用MnO₂/SG复合电极，组装了超级电容器，在0.5 A·g^-1的电流密度下，比电容达343.6 F·g^-1；经5000次循环，其容量保持率为83.8%；在500 W·kg^-1的功率密度下，其能量密度达11.93 W·h·kg^-1。因此，MnO₂/SG复合电极是一种性能优异的赝电容材料，在电化学储能领域有良好的应用前景。

Three-dimensional strutted graphene loading manganese oxide for supercapacitor

Graphene has shown superiority for advanced carbon electrodes in supercapacitors， characterized by high power density but limited energy density. Combining pseudocapacitive materials with graphene can alleviate the problem. This work synthesized the three-dimensional strutted graphene (SG) via the ammonium-salt-assisted sugar-blowing method, and the self-supporting MnO₂/SG porous monolith was then constructed via growing manganese oxide (MnO₂) nanorod array on the SG support in hydrothermal process. When tested in supercapacitor， the MnO₂/SG hybrid electrode achieved a high specific capacitance of 343.6 F·g^-1 at a current density of 0.5 A·g^-1， exhibiting excellent cycling stability with 83.8% capacitance retention after 5000 cycles. The symmetric supercapacitor further showed a high energy density of 11.93 W·h·kg^-1 at a power density of 500 W·kg^-1. The impressive result indicates a promising prospect of the excellent MnO₂/SG hybrid to be applied to electrochemical energy storage.