Fabrication of hierarchical Ni nanowires@ NiCo-layered double hydroxide nanosheets core-shell hybrid arrays for high-performance hybrid supercapacitors. (20th January 2023)

• Record Type: Journal Article
• Authors: Mahieddine, Abdelkadir; Adnane-Amara, Leila
• Is Part Of: Electrochimica acta. Volume 439(2023)
• Publication Date: 2023-01-20
• Subjects: NiCo LDHs -- Hydrothermal reaction -- Hierarchical Nickel nanowires -- Activated carbon -- Hybrid supercapacitor; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2022.141622
• Languages: English
• ISSNs: 0013-4686

Abstract

Highlights: The core-shell structured hierarchical Ni nanowires and NiCo LDHs nanosheets were prepared for the first time by hydrothermal method. NiCo LDH@h-Ni NWs exhibited a specific capacity of 1486 C/g at a current density of 1 A/g. NiCo LDH@h-Ni NWs// AC hybrid supercapacitor delivered a high energy density of 72.22 Wh/kg at the power density of 800 W/kg. The proposed mechanisms for improved supercapacitor performance were well analyzed and demonstrated. Abstract: Layered double hydroxides (LDHs) are electrode materials with high specific capacity due to their structure which has a tunable interlayer spacing, however, the disadvantages of their low conductivity and electrochemically limited sites prevent their application in supercapacitors. In this study, we synthesized a high electrochemical performance electrode material with a core-shell structure based on hierarchical nickel nanowires (core) and NiCo LDHs nanosheets (shell). First, hierarchical nickel nanowires, h-Ni NWs, were prepared by the reduction of Ni 2+ ions by hydrazine N2 H4 . Then with the hydrothermal method, the hierarchical nickel nanowires were coated with NiCo LDHs to improve the electrical conductivity of the latter. The electrochemical results showed that the NiCo LDHs@h-Ni NWs electrode had a specific capacity of 1486 C/g at a current density of 1 A/g in 6 M KOH electrolyte with excellent capacity retention (89.7%) after 10, 000 charge-discharge cycles at 20 A/g. Due to the synergistic interaction between nickel nanowires and NiCo LDHs which provides excellent conductivity, durability, efficient mesoporous network, and suitable channels for fast ion/electron transfer. In addition, a hybrid supercapacitor (HSC) was fabricated by combining the NiCo LDHs@h-Ni NWs electrode (battery type) with activated carbon (EDLC). The fabricated device provided a high energy density of 72.22 Wh/kg at 800 W/kg, and a maximum power density of 16 kW/kg, the HSC provided an energy density of 50.44 Wh/kg and outstanding cycling stability (88.1% retention after 10, 000 cycles). Graphical abstract: Image, graphical abstract