Department of Chemistry, Northeastern University, Shenyang, 110819, China.
Nanoscale. 2013 Sep 7;5(17):7984-90. doi: 10.1039/c3nr02710d.
Here we demonstrate a high energy density asymmetric supercapacitor with nickel oxide nanoflake arrays as the cathode and reduced graphene oxide as the anode. Nickel oxide nanoflake arrays were synthesized on a flexible carbon cloth substrate using a seed-mediated hydrothermal method. The reduced graphene oxide sheets were deposited on three-dimensional (3D) nickel foam by hydrothermal treatment of nickel foam in graphene oxide solution. The nanostructured electrodes provide a large effective surface area. The asymmetric supercapacitor device operates with a voltage of 1.7 V and achieved a remarkable areal capacitance of 248 mF cm(-2) (specific capacitance of 50 F g(-1)) at a charge/discharge current density of 1 mA cm(-2) and a maximum energy density of 39.9 W h kg(-1) (based on the total mass of active materials of 5.0 mg). Furthermore, the device showed an excellent charge/discharge cycling performance in 1.0 M KOH electrolyte at a current density of 5 mA cm(-2), with a capacitance retention of 95% after 3000 cycles.
在这里，我们展示了一种具有高能量密度的不对称超级电容器，其阴极采用氧化镍纳米片阵列，阳极采用还原氧化石墨烯。通过种子介导的水热法在柔性碳纤维布基底上合成了氧化镍纳米片阵列。通过在氧化石墨烯溶液中对三维（3D）泡沫镍进行水热处理，在 3D 泡沫镍上沉积了还原氧化石墨烯片。纳米结构电极提供了较大的有效表面积。不对称超级电容器装置的工作电压为 1.7 V，在 1 mA cm(-2)的充放电电流密度下，面积电容达到 248 mF cm(-2)（比容量为 50 F g(-1)），最大能量密度为 39.9 W h kg(-1)（基于 5.0 mg 活性材料的总质量）。此外，该器件在 1.0 M KOH 电解质中以 5 mA cm(-2)的电流密度表现出优异的充放电循环性能，在 3000 次循环后电容保持率为 95%。
