Two‐step electrodeposition of Hausmannite sulphur reduced graphene oxide and cobalt‐nickel layered double hydroxide heterostructure for high‐performance supercapacitor

Abstract

Summary Hausmannite/sulphur reduced graphene oxide (MO/RGO‐S) and cobalt‐nickel layered double hydroxide (CN) composite was synthesized through a two‐step electrodeposition approach. This process began with galvanostatic electrodeposition of MO/RGO‐Son a nickel foam, followed by cyclic voltammetry electrodeposition of CN. The inclusion of RGO‐S increases the electrical conductivity of the active material (AM) and its wettability while Mn3O4 (MO) enhances the pseudocapacitive active sites which help to increase the specific capacity of CN. The materials' electrochemical evaluations were carried out via three‐ and two‐electrode configurations using 2 M KOH electrolyte. An enhanced composite material (MO/RGO‐S‐50@CN) produced a phenomenal specific capacity of 582.1 mA h g−1 in a three‐electrode configuration at 0.5 A g−1. The device (MO/RGO‐S‐50@CN//CCBW) consisting of MO/RGO‐S‐50@CN and activated carbon from cooked chicken bone waste (CCBW) as positive and negative electrodes, respectively delivered specific energy of 56.0 Wh kg−1 with a specific power of 515.0 W kg−1 at a specific current of 0.5 A g−1. The device produced capacity retention of 85.1% and coulombic efficiency of 99.7% at 10 000 galvanostatic charge‐discharges cycles at 6 A g−1. Because of these excellent results, the fabricated materials demonstrated great potential for application as a high specific energy supercapacitor.

Exploration of metal-layered double hydroxide composite material for hybrid capacitor produced by facile and efficient electrodeposition process

“…The synthesis of CN-LDH was similar to the one reported in our previous work [28]. In brief, 0.01 M each of Ni (NO3)2•6H2O and Co (NO3)2•6H2O were dissolved in 50 ml of DW and stirred vigorously for 30 minutes to form the homogeneous solution labeled S2.…”

“…The preparation of NF was done as reported in our previous work [26]. Briefly, NF was shaped into (1 cm 2 cm) rectangular pieces.…”

“…The variance of real capacitance C ω and imaginary capacitance C ′ ω with frequency (f) is demonstrated in Fig.7(d). These capacitances are calculated from the equations expressed below[26]:where, | 𝑍 𝜔 |, 𝑍 𝜔 and 𝑍 ′ 𝜔 are the magnitude of impedance, real and imaginary impedances (Ω), respectively. 𝜔 denote the angular frequency (rad s -1 ) which is given by 𝜔 2𝜋𝑓.…”

Recent advances in Ni-materials/carbon nanocomposites for supercapacitor electrodes

“…113 A Hausmannite/sulfur rGO (MO/rGO-S)/Co–Ni layered double hydroxide (MO/rGO-S-50/CN) composite and the device consisting of MO/rGO-S-50/CN (+) and AC (−) delivered excellent results for using in a high specific energy supercapacitor. 114 NiCo-LDH hollow micro-tunnels strongly coupled with a higher-Fermi-level graphene quantum dots (GQDs) (GQDs/LDH-2) electrode yield an excellent capacitance of 1628 F g −1 at 1 A g −1 that when coupled with an rGO electrode (−) showed a 46 W h kg −1 energy density. 115 MWCNT/GO nanoribbon/Graphitic carbon nitride NNi-colayered double hydroxide/Ni foam was prepared and exhibited high specific capacitance and exceptional performance.…”