2D-2D nanohybrids of Ni–Cr-layered double hydroxide and graphene oxide nanosheets: Electrode for hybrid asymmetric supercapacitors. (20th August 2022)

• Record Type: Journal Article
• Authors: Padalkar, Navnath S.; Sadavar, Shrikant V.; Shinde, Rohini B.; Patil, Akash S.; Patil, Umakant M.; Magdum, Vikas V.; Chitare, Yogesh M.; Kulkarni, Shirin P.; Bulakhe, Ravindra N.; Parale, Vinayak G.; Gunjakar, Jayavant L.
• Is Part Of: Electrochimica acta. Volume 424(2022)
• Publication Date: 2022-08-20
• Subjects: Self-assembly -- Energy storage -- Graphene oxide -- Hybrid asymmetric supercapacitor -- Nanohybrids; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2022.140615
• Languages: English
• ISSNs: 0013-4686

Abstract

Highlights: 2D graphene oxide (GO) nanosheets are employed to improve the electrode performance of layer double hydroxide (LDH). Nanohybrids of Ni–Cr-LDH and GO nanosheets (NCG) are prepared via electrostatic self-assembly method. NCG nanohybrids enables self-assembly with high surface area, mesoporous morphology, high electrical conductivity, and high charge transfer kinetics. The aqueous hybrid supercapacitors device displays high energy density (ED) of 51.85 Wh kg –1 and power density (PD) of 1.34 kW kg –1 . All-solid-state hybrid supercapacitor displays exceptional ED of 38.51 Wh kg–1 and PD of 1.33 kW kg –1 Abstract: Nanohybrids of 2D Ni–Cr-layered double hydroxide (Ni–Cr-LDH) and graphene oxide (GO) nanosheets (Ni–Cr-LDH–GO) are prepared by electrostatic self-assembly between cationic Ni–Cr-LDH nanosheets and anionic GO nanosheets. Anionic GO nanosheets provide charge-transporting conducting channels leading to remarkably improved electrochemical activity of Ni–Cr-LDH–GO nanohybrid. The unique Ni–Cr-LDH–GO nanohybrid electrodes enable stable electrochemical structure, abundant active electrochemical sites, and fast electron-transporting channels, which play a crucial role in improving the specific capacities, cycle stability, and rate capacity. As a result, Ni–Cr-LDH–GO nanohybrid electrodes demonstrate excellent electrochemical performance with a specific capacity of 815 C g –1 at 1 A g –1, superior to pristine Ni–Cr-LDH (354 C g –1 ). An aqueous hybrid supercapacitor (AHS) device displays outstanding electrochemical performance with improved energy density (ED) of 51.85 Wh kg –1 and power density (PD) of 1.34 kW kg –1 . An all-solid-state hybrid supercapacitor (ASSHS) displays ED of 38.51 Wh kg –1 and PD of 1.33 kW kg –1 . Furthermore, AHS and ASSHS show excellent cycling stability of 89% and 86% capacitance retention after 10, 000 galvanostatic charge/discharge (GCD) cycles, respectively. The present exfoliation-restacking strategy provides a useful method for developing a 2D-2D Ni–Cr-LDH–GO structure for a highly active hybrid-type supercapacitor structure. Graphical abstract: Exfoliation-reassembly strategy is use to synthesize 2D-2D Ni–Cr-LDH–GO nanohybrids. Owing to the high surface area and high electrical conductivity, Ni–Cr-LDH–GO nanohybrids demonstrated excellent electrochemical performance as a redox electrode in hybrid asymmetric supercapacitor. Image, graphical abstract