Ni, Co-double hydroxide wire structures with controllable voids for electrodes of energy-storage devices

作     者：Jin Kyu Kim Chang Soo Lee Jae Hun Lee Jung Tae Park Jong Hak Kim Jin Kyu Kim;Chang Soo Lee;Jae Hun Lee;Jung Tae Park;Jong Hak Kim

作者机构：Department of Chemical and Biomolecular EngineeringYonsei University50 Yonsei-roSeodaemun-guSeoul 03722Republic of Korea Department of Chemical EngineeringKonkuk University120 Neungdong-roGwangjin-guSeoul 05029Republic of Korea 

出 版 物：《Journal of Materials Science & Technology》 (材料科学技术（英文版）)

年 卷 期：2020年第52卷第20期

页      面：126-135页

核心收录：

学科分类：080801[工学-电机与电器] 0808[工学-电气工程] 081704[工学-应用化学] 08[工学] 0817[工学-化学工程与技术] 0806[工学-冶金工程] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 0802[工学-机械工程] 0801[工学-力学（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：This work was supported by the National Research Foundation(NRF)of South Korea funded by the Ministry of Science and ICT Republic of Korea(Nos.NRF-2017R1A4A1014569 and NRF2018M3A7B4071535)。 

主　　题：Ni,Co-double hydroxide Nanowire Electrode Energy-storage device Supercapacitor 

摘      要：We re port the facile synthesis of Ni,Co-double hydroxide wire(NCHW)-based electrodes directly grown on a conductive substrate via a hydrothermal process.Various NCHW nanostructures were grown on Ni foam,and the growth was controlled using different compositions of solvents(ethanol and water).With increasing volume ratio of ethanol to water,the density of the wires decreased,and the spatial voids between the wires increased.The formation of large empty spaces improved the electrochemical performance because the exposure of a large surface area of the structure to the electrolyte resulted in a large number of active sites and facile electrolyte penetration into the structure.The different NCHW structures were ascribed to the pivotal role of the solvent in the urea hydrolysis;the solvent triggered the formation of hydroxides during the hydrothermal synthesis.The electrochemical performance of the NCHW electrodes was investigated via galvanostatic charge/discha rge tests,cyclic voltammetry,and electrochemical impedance spectroscopy.The highest specific capacitance was 1694.7 m F/cm^2 at 2 mA/cm^2,with excellent capacitance retention of 81.5% after 5000 cycles.The superior electrochemical performance of the NCHW electrodes is attributed to the large number of active sites and facile electrolyte diffusion into the structure,due to the well-organized structure with an optimized density of nanowires and large voids between the wires.