成果归属作者：

孙黎 ; 张以河

成果归属机构：

材料科学与工程学院

作者：

Xie, Feng ; Yang, Kun ; Zhu, Haoxian ; Li, Wei ; Zhang, Lei ; Sun, Li ; Zhang, Yihe

单位：

China Univ Geosci Beijing, Beijing Key Lab Mat Utilizat Nonmet Minerals & Sol, Sch Mat Sci & Technol, Natl Lab Mineral Mat, Engn Res Ctr, Minist Educ Geol Carbon Storage & Low, Beijing 100083, Peoples R China

关键词：

CARBON NANOFIBERS; ENERGY-STORAGE; FOAM

摘要：

The bimetallic sulfide of NiCo 2 S 4 generally show better electrochemical performance than its bimetallic oxide counterpart in supercapacitor electrode applications. In this work, we theoretically explain their essential differences in reaction mechanisms through density functional theory, including their OH - adsorption energy, energy band structure, total and projected density of states, as well as d -band center of Ni and Co, which confirms the intrinsic advantage of NiCo 2 S 4 over NiCo 2 O 4 as electrode material for alkaline supercapacitors. Then, through electrospinning, we fabricate porous nanofibers of NiCo 2 S 4 -NF and NiCo 2 O 4 -NF with similar porous, fibrous morphology stacked by nanoparticles, of which NiCo 2 S 4 -NF gives obviously superior performance in alkaline electrolyte as supercapacitor electrodes, verifying the theoretical prediction. Moreover, an rGO coverage layer was in -situ incorporated to fabricate porous nanofibers of rGO@NiCo 2 S 4 -NF, which includes an additional surface rGO wrapping layer. The 1D and porous architecture renders rGO@NiCo 2 S 4 -NF more exposed OH - adsorption sites to induce active redox reactions, while the rGO coverage further stabilized the nanofibers and ensures inter-fiber charge transfer. Due to the combination of morphology optimization and carbon combination, rGO@NiCo 2 S 4 -NF delivers enhanced capacity, cycle stability and rate ability than NiCo 2 S 4 -NF and NiCo 2 O 4 -NF. Using rGO@NiCo 2 S 4 -NF, asymmetric supercapacitors are assembled, which also exhibits promising energy densities and power densities.

基金：

National Natural Science Foundation of China [52202317]

语种：

英文

DOI：

10.1016/j.jallcom.2024.175005

来源：

JOURNAL OF ALLOYS AND COMPOUNDS,2024():.

出版日期：

2024-10-05

提交日期：

2024-07-09

引用参考：

Xie, Feng; Yang, Kun; Zhu, Haoxian; Li, Wei; Zhang, Lei; Sun, Li; Zhang, Yihe. Electrospun NiCo 2 S 4 nanofibers decorated by rGO wrapping with high OH- adsorption ability for alkaline supercapacitors[J]. JOURNAL OF ALLOYS AND COMPOUNDS,2024():.