Cr-doped (Co, Ni)3S4/Co9S8/Ni3S2 nanowires/nanoparticles grown on Ni foam for hybrid supercapacitor

JOURNAL OF ALLOYS AND COMPOUNDS

卷:835

Article

Hai, Yang¹  Tao, Keyu¹  Dan, Huamei¹  Liu, Li¹  Gong, Yun¹ 

[1] Chongqing Univ, Coll Chem & Chem Engn, Dept Appl Chem, Chongqing 401331, Peoples R China

关键词: Cr-doping;    Spinel-type;    (Co, Ni)(3)S-4;    Ni3S2;    Supercapacitor;   

DOI  :  10.1016/j.jallcom.2020.155254

来源: Elsevier

【 摘 要 】

Utilizing a 4: 1 of Co/Cr molar ratio in the starting material, Cr-doped (Co, Ni)(3)S-4/Co9S8/Ni3S2 nanowires/ nanoparticles can grow on Ni foam (NF) hydrothermally. The sample shows excellent supercapacitive performance with a specific capacity of 310.3 mAh g(-1) at 1 A g(-1) (320.27 mAh cm(-2) at 1 mA cm(-2)), which is superior to Ni3S2/NF, (Co, Ni)(3)S-4/Ni3S2/NF and less Cr-doped (Co, Ni)(3)S-4/Co9S8/Ni3S2/NF. Density functional theory (DFT) calculations disclose that the incorporation of Cr into Ni3S2 or spinel-type Ni3S4 can improve the electron conductivity, promote the electron transfer from Ni/S to Cr, and boost the adsorption of -OH, which is evidenced from XPS spectra. It promotes the electrochemical reaction between active sites and OH- in solution, resulting in enhanced supercapacitive property. Furthermore, it is expected that the doped Cr substitutes the B position of spinet-type AB(2)S(4) (such as Ni(II)Ni(III)2S(4)). The Cr-doped (Co, Ni)(3)S-4/Co9S8/Ni3S2/NF//activated carbon asymmetrical supercapacitor (ASC) shows a maximum energy density of 53.24 Wh kg(-1) at power density of 543.26 W kg(-1), which is superior to previously reported ASC devices. (C) 2020 Elsevier B.V. All rights reserved.

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