NiCo_2O_4微球的制备及其电化学性能

通过简单的水热法以及后续热处理,成功合成介孔NiCo_2O_4微球。利用FESEM、TEM、XPS和电化学工作站对样品的表面形貌、元素价态和电化学性能进行表征。结果表明:合成的NiCo_2O_4拥有丰富的多孔纳米针状结构,表现出较高的比表面积。由于这种三维多孔纳米结构,当NiCo_2O_4微球作为电极材料时,展现出优异的电容特性,在1A·g-1的电流密度下比电容高达1 554F·g-1,而且当电流密度增加到20A·g-1时,电容保持率为87.5%。另外,在5A·g-1的电流密度下,经过2 000次的充放电循环后,比电容仍能保持初始电容的90.4%。良好的电化学性能表明,NiCo_2O_4微球是一种理想的超级电容器电极材料。

Synthesis and electrochemical properties of NiCo2 O4 microsphere

The mesoporous NiCo2 O4 microsphere was synthesized via a facile hydrothermal method followed by thermal annealing treatment.The surface morphology,valence of the elements and electrochemical performance of the samples were characterized by FESEM,TEM,XPS and the electrochemical workstation.The results show that the as-prepared NiCo2 O4 microsphere presents 3D structure constructed with rich porous nanoneedles,and deliveres a high specific surface area.The NiCo2 O4 microsphere electrode reveals amazing pseudocapacitive properties with high specific capacitance (1554 F·g-1 at 1 A·g-1 )and a favorable rate capability (87.5% from 1 to 20 A·g-1 )due to the 3D structure.Moreover,the specific capacitance remains 90.4% of its initial value after 2000 cycles at 5 A·g-1 .The good electrochemical performances indicate that NiCo2 O4 microsphere could be a promising material for supercapacitor electrode.