摘要
采用快速凝固与脱合金化相结合的方法制备纳米多孔Ni、Ni-Co合金,分别经腐蚀与退火获得纳米多孔NiO、NiCo_2O_4,采用XRD、SEM、TEM、N_2吸附-脱附等对多孔NiO、NiCo_2O_4电极的物相、形貌结构、孔径分布进行表征,并通过循环伏安、恒电流充放电等方法测试多孔电极的电化学性能。结果表明,得到的纳米多孔NiO具有均匀的"泥裂"式结构,在1A·g^(-1)电流密度下比电容为375 F·g^(-1),当电流密度增加至20 A·g^(-1)时的比容保持率为67.5%,在4 A·g^(-1)电流密度下循环充放电1 000次,比容保持率为81.7%;NiCo_2O_4形成典型的开放式纳米多孔双连续结构,其在1A·g^(-1)电流密度下比电容为674 F·g^(-1),当电流密度增加至20 A·g^(-1),比容保持率达72.0%;在4 A·g^(-1)电流密度下循环充放电1 000次,比容保持率达92.9%,双连续纳米多孔结构及其提供的机械稳定性,使得NiCo_2O_4表现出更为优异的超电容性能。
Nanoporous Ni and Ni-Co alloys were prepared by a method of rapid quenching and de-alloying, and the samples were corroded and annealed to synthesize the nanoporous NiO and NiCo2O4 material respectively.The composition, morphology and microstructure of NiO and NiCo2O4 were analyzed by XRD, SEM, TEM and N2 adsorption-desorption. The electrochemical performance was investigated by cyclic voltammetry and galvanostatic charge-discharge. The results show that the porous NiO has a uniform ＂mud crack＂ structure. The specific capacitance of nanoporous NiO is 375 F·g-1 at current density of 1A·g-1 and its retention ratio remains at 67.5%when the current density increases to 20 A·g-1. After galvanostatic charge-discharge 1 000 cycles at 4 A·g-1, the retention ratio of specific capacitance is 81.7%. The porous NiCo2O4 has a lamellar structure. The specific capacitance of nanoporous NiCo2O4 is 674 F·g-1 at current density of 1A·g-1 and its retention ratio remains at72.0% when the current density increases to 20 A·g-1. After galvanostatic charge-discharge 1 000 cycles at 4A·g-1, the retention ratio of specific capacitance is 92.9%. NiCo2O4 shows superior supercapacitive performance because of the mechanical stability of the bicontinuous nanoporous structure.
作者
周琦
李志洋
郑斌
ZHOU Qi;LI Zhi-Yang;ZHENG Bin(State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,Lanzhou University of Technology, Lanzhou 730050, Chin)
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
2018年第6期1103-1109,共7页
Chinese Journal of Inorganic Chemistry
基金
国家自然科学基金(No.51661018)资助项目
关键词
快速凝固
脱合金化
双金属氧化物
电化学性能
rapid quenching
de-alloying
metallic oxide
electrochemical performance
