{"title":"Bimetallic nickel-cobalt sulfide grown on graphene foam for high-performance asymmetric supercapacitor","authors":"Zhengyan Chen, Runzhuo Xue, Baoli Fan, Yilan Wang, Wenhui Tian, Lu Pei, Yanling Jin, Zhengzheng Guo, Zhenfeng Sun, Fang Ren, Penggang Ren","doi":"10.1016/j.jallcom.2024.176483","DOIUrl":null,"url":null,"abstract":"Although bimetallic nickel-cobalt sulfides (Ni/Co-S) have shown promising candidates as pseudocapacitive materials with excellent electrochemical performance, achieving high energy density, high power density, and good cyclability of Ni/Co-S electrode remains a challenge. In this study, the graphene foam (GF) with a three-dimensional (3D) skeleton was successfully prepared using a chemical vapor deposition (CVD) method. Subsequently, Ni/Co-S was in situ grown on the GF through a two-step hydrothermal method. A series of Ni/Co-S@GF- (=1, 2, 3) electrodes were prepared and optimized for electrochemical performance by regulating the molar ratio of Ni/Co salt precursors (3:1, 4:1, 5:1). The abundant pore structure of Ni/Co-S@GF not only facilitates ion migration, but also provides numerous electrochemical redox active sites for reactions. When utilized as electrodes in supercapacitors, the Ni/Co-S@GF-2 with a Ni/Co salt’s molar ratio of 4:1 displays a specific capacity of 4.68 C cm at 1 mA cm. Furthermore, an asymmetric supercapacitor (ASC) was assembled using the optimal Ni/Co-S@GF-2 as cathode and Walnut shell-derived porous carbon as anode to evaluate the actual energy storage characteristics of the device. The ASC delivers a high power density of 822.86 mW cm at an energy density of 32.0 mWh cm. This work presents a promising approach for designing and preparing nickel-cobalt sulfides for application in flexible energy storage devices.","PeriodicalId":344,"journal":{"name":"Journal of Alloys and Compounds","volume":null,"pages":null},"PeriodicalIF":5.8000,"publicationDate":"2024-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Alloys and Compounds","FirstCategoryId":"88","ListUrlMain":"https://doi.org/10.1016/j.jallcom.2024.176483","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Although bimetallic nickel-cobalt sulfides (Ni/Co-S) have shown promising candidates as pseudocapacitive materials with excellent electrochemical performance, achieving high energy density, high power density, and good cyclability of Ni/Co-S electrode remains a challenge. In this study, the graphene foam (GF) with a three-dimensional (3D) skeleton was successfully prepared using a chemical vapor deposition (CVD) method. Subsequently, Ni/Co-S was in situ grown on the GF through a two-step hydrothermal method. A series of Ni/Co-S@GF- (=1, 2, 3) electrodes were prepared and optimized for electrochemical performance by regulating the molar ratio of Ni/Co salt precursors (3:1, 4:1, 5:1). The abundant pore structure of Ni/Co-S@GF not only facilitates ion migration, but also provides numerous electrochemical redox active sites for reactions. When utilized as electrodes in supercapacitors, the Ni/Co-S@GF-2 with a Ni/Co salt’s molar ratio of 4:1 displays a specific capacity of 4.68 C cm at 1 mA cm. Furthermore, an asymmetric supercapacitor (ASC) was assembled using the optimal Ni/Co-S@GF-2 as cathode and Walnut shell-derived porous carbon as anode to evaluate the actual energy storage characteristics of the device. The ASC delivers a high power density of 822.86 mW cm at an energy density of 32.0 mWh cm. This work presents a promising approach for designing and preparing nickel-cobalt sulfides for application in flexible energy storage devices.
期刊介绍:
The Journal of Alloys and Compounds is intended to serve as an international medium for the publication of work on solid materials comprising compounds as well as alloys. Its great strength lies in the diversity of discipline which it encompasses, drawing together results from materials science, solid-state chemistry and physics.