摘要
过渡金属氧化物赝电容材料由于具有多电子转移的氧化还原反应特性,往往具有较高的理论容量,使其在储能领域备受关注。但是作为超电容电极,电子传输速率低、活性物质利用率低以及稳定性较差等缺点限制了其广泛的实际应用。对金属氧化物进行多级及介孔结构的设计是解决上述问题、发展高效超电容电极的有效途径。在此,我们报道了一种多级介孔的NiO阵列电极材料(NiO-HMAs),该材料通过自生成-牺牲模板法制备。作为超电容电极,NiO-HMAs表现出超高的电容量(3114 F g~(-1),5 mA cm~(-2))和良好的循环稳定性能(>91%for2000 cycles)。该材料优异的电容性能主要来源于多级介孔阵列结构的设计使得活性材料达到接近100%的利用率,从而使电极的赝电容和双电层电容都大大提高。
Transitional metal oxides based pseudocapacitors usually have large theoretical pseudocapacitive values,but the low utilization and poor stability limit their practical applications.The rigorous design of architectures with hierarchical and mesoporous structure is an efficient strategy to address these issues and helps to develop high performance of transitional metal oxide pseudocapacitors.Here,we report a hierarchical mesoporous NiO nanoarrays(NiO-HMAs) electrode fabricated by an effective self-generated sacrificial template approach.As a supercapacitor electrode,NiO-HMAs exhibit ultrahigh specific capacitance(3114 F g~(-1) at the current density of 5 mA cm~(-2)) and excellent cycling performance(>91% for 2000 cycles).The ultrahigh capacitive performance mostly stems from the nearly full redox reaction of NiO from the unique hierarchical mesoporous architecture,combining with the raised electrical double-layer capacitance at the enlarged surface.
引文
