摘要
采用离子刻蚀和化学气相沉积法制备出具有沸石咪唑酯骨架(ZIFs)型双壳层纳米笼状的CoS/NiCo2S4并组装成超级电容器。该结构有较大的比表面积(98 m2·g^-1),合适的孔道(孔径4 nm),且保留了ZIFs骨架构型。作为电极活性材料时,具有良好的结构稳定性和电化学活性,有利于增强所组装的超级电容器的循环稳定性和比容量。在三电极体系中,在1 A·g^-1的电流密度下,容量为1 230 F·g^-1;在3 A·g^-1电流密度下循环9 000圈后,初始电容保持率为76.6%。在以该电极、活性炭电极与KOH/聚乙烯醇(PVA)凝胶态电解质组装的器件中,当功率密度为702 W·kg^-1时,能量密度达31.6 Wh·kg^-1;在7 056 W·kg^-1的高功率密度下,仍保持16.5 Wh·kg^-1的能量密度。
Double-shell nanocage CoS/NiCo2S4 was prepared by ion erosion and chemical vapor deposition using ZIF-67. The supercapacitor based on CoS/NiCo2S4 exhibited high specific capacitance and stability, due to its high specific surface area (98 m^2,g^-1), abundant interconnected channel (4 nm pole diameter), and stable cavity skeleton. The three-electrode cell based on CoS/NiCo2 S/Nifoam maintained 76.6% initial capacitance at 3 A·g ^-1 current density after 9 000 cycles. The cell gained a specific capacitance of 1 230 F·g ^-1 at 1 A·g ^-1 due to increasing active sites and rapid electron/ion transports for Faradaic reactions. The results can reflect the superior electrochemical performance of double-shell nanocage CoS/NiCo2 S4 on specific capacitance and cycling stability. The supercapacitor was assembled by CoS/NiCo2S /Ni foam, active carbon electrode and KOH/polyvinyl alcohol gel electrolyte. The device retention was 74.8% at a current density of 3 A·g^-1 after 7 000 cycles. The device also achieved an energy density of 16.5 Wh·kg^-1 at a high power density of 7 056 W kg^-1. Even at a power density of 702 W kg^-1, a high energy density of 31.6 Wh kg^-1 can be obtained. The asymmetric device exhibited excellent energy density, power density and cycle stability. In a practical application testing, two series-connected solid-state supercapacitors provided stable electrical energy, enabling the LEDs to be successfully illuminated.
作者
谢方
任雨
周玉青
孙岳明
王育乔
XIE Fang;REN Yu;ZHOU Yu-Qing;SUN Yue-Ming;WANG Yu-Qiao(Institute of Advanced Materials, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China;School of Chemical Engineering and Materials, Nanjing Polytechnic Institute, Nanjing 210048, China)
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
2019年第9期1635-1641,共7页
Chinese Journal of Inorganic Chemistry
基金
国家自然科学基金(No.61774033)
国家重点研发计划重点专项(No.2018YFC1803100)
江苏省青蓝工程资助
关键词
硫化物
电化学
介孔材料
空腔
循环稳定性
比容量
sulfur
electrochemistry
mesoporous materials
cavity
cycling stability
specific capacitance
