A high-performance asymmetric supercapacitor using composite electrodes of layered double hydroxides and holey reduced graphene oxide. (15th August 2022)

• Record Type: Journal Article
• Authors: Yan, Wei; Zhang, Ying; Zeng, Ting; Zhang, Yuanyuan; Wan, Qijin; Yang, Nianjun
• Is Part Of: Journal of energy storage. Volume 52:Part B(2022)
• Publication Date: 2022-08-15
• Subjects: Asymmetric supercapacitor -- Layered double hydroxides -- Holey reduced graphene oxide -- Supercapacitor performance; Energy storage -- Periodicals; Energy storage -- Research -- Periodicals; 621.3126
• DOI: 10.1016/j.est.2022.104899
• Languages: English
• ISSNs: 2352-152X

Abstract

Abstract: Layered double hydroxide (LDH) materials are promising candidates to achieve high specific capacities of supercapacitors (SCs). However, their electrical conductivities are low, restricting their SC performance. Herein, a one-step solvothermal technique is employed to synthesize a hybrid material of nickel‑manganese LDH/holey reduced graphene oxide (NiMn-LDH/hrGO). The addition of hrGO improves the conductivity and surface area of the NiMn-LDH/hrGO electrode. It thus exhibits a specific capacity of as high as 302.0 C g −1 at a current density of 1 A g −1 and excellent capacity retention even after 2000 cycles. In an asymmetric supercapacitor (ASC), the NiMn-LDH/hrGO electrode is assembled with a Bi(OH)3 /hrGO electrode. This ASC exhibits a specific capacity of 237.6 C g −1 at a current density of 1 A g −1, cycling stability of 80.5% after 2000 cycles at a current density of 10 A g −1, and an energy density of as high as 59.9 Wh kg −1 at a power density of 901.5 W kg −1 . The proposed method handles the challenges posed by electrochemical capacitors and paves a way to ensemble high performance SCs. Graphical abstract: A one-step hydrothermal technique is employed to synthesize a hybrid material of nickel‑manganese LDH/holey reduced graphene oxide (NiMn-LDH/hrGO). Unlabelled Image Highlights: The NiMn-LDH/hrGO prepared by a solvothermal technique exhibits excellent electrochemical performance. NiMn-LDH/hrGO composite displays higher capacitance and rate performance than NiMn-LDH. The NiMn-LDH/hrGO//Bi(OH)3 /hrGO asymmetric supercapacitor delivers a high energy density.