摘要
基于 Graphene 三维(3D ) 宏观的材料最近在电气化学的精力变换和存储由他们的令人激动的潜力的优点吸引了增加的兴趣。这里，我们报导灵巧的一步舞策略准备机械地强壮、电子上传导性的 graphene/Ni (哦) 有一个互连的多孔的网络的 2 合成 hydrogels。没有增加任何另外的文件夹或传导性的添加剂，合成 hydrogels 直接被用作 3D supercapacitor 电极材料。包含 82 wt.% Ni 的优化合成 hydrogel (哦) 2 与优秀骑车在 40 mV/s (63% 电容保留) 以 5 mV/s 和 785 F/g 的扫描率展出了 1,247 F/g 的一个特定的电容稳定性。3D hydrogels 的能力极大地超过 graphene 表和 Ni 的物理混合物的(哦) 2 nanoplates (在 40 mV/s 的 309 F/g ) 。一样的策略也被使用制作 graphene 碳 nanotube/Ni (哦) 有进一步改进的特定的电容(在 5 mV/s 的 1,352 F/g ) 和率能力(在 40 mV/s 的 66% 电容保留) 的 2 第三的合成 hydrogels。这里获得的两合成 hydrogels 能交付高精力密度(43 和 47 Wh/kg，分别地) 并且力量密度(8 和 9 kW/kg，分别地) ，为 supercapacitor 应用使他们成为吸引人的电极材料。这研究打开一条新小径到功能的 3D graphene 的设计和制造合成材料，和罐头显著地包括精力存储并且在以外影响宽广区域。
Graphene-based three-dimensional （3D） macroscopic materials have recently attracted increasing interest by virtue of their exciting potential in electrochemical energy conversion and storage. Here we report a facile one-step strategy to prepare mechanically strong and electrically conductive graphene/Ni（OH）2 composite hydrogels with an interconnected porous network. The composite hydrogels were directly used as 3D supercapacitor electrode materials without adding any other binder or conductive additives. An optimized composite hydrogel containing -82 wt.% Ni（OH）2 exhibited a specific capacitance of -1,247 F/g at a scan rate of 5 mV/s and -785 F/g at 40 mV/s （-63% capacitance retention） with excellent cycling stability. The capacity of the 3D hydrogels greatly surpasses that of a physical mixture of graphene sheets and Ni（OH）2 nanoplates （-309 F/g at 40 mV/s）. The same strategy was also applied to fabricate graphene-carbon nanotube/Ni（OH）2 ternary composite hydrogels with further improved specific capacitances （-1,352 F/g at 5 mV/s） and rate capability （-66% capacitance retention at 40 mV/s）. Both composite hydrogels obtained here can deliver high energy densities （-43 and -47 Wh/kg, respectively） and power densities （-8 and -9 kW/kg, respectively）, making them attractive electrode materials for supercapacitor applications. This study opens a new pathway to the design and fabrication of functional 3D graphene composite materials, and can significantly impact broad areas including energy storage and beyond.
