Hierarchical Structured Ni₃S₂@rGO@NiAl-LDHs Nanoarrays: A Competitive Electrode Material for Advanced Asymmetrical Supercapacitors

Abstract

In this account, a well-aligned hierarchical nickel sulfide@­reduced graphene oxide@­nickel aluminum layered double hydroxides composite (denoted as Ni3S2@­rGO@­NiAl-LDHs) supported on a Ni-foam substrate is successfully designed and constructed via a successive hydrothermal process. Ni3S2 nanorod arrays grown on Ni foam could provide large open space and short ions diffusion path. Graphene with high specific surface area and excellent conductivity can effectively transfer charges; NiAl-LDHs has large contact area with electrolyte, thus enabling a fast and reversible redox process, which could improve the specific capacitance. As a consequence, the Ni3S2@­rGO@­NiAl-LDHs fulfills superior specific capacity, pleasurable charge–discharge rate, and outstanding lifespan. Moreover, an advanced asymmetrical device is assembled by employing Ni3S2@­rGO@­NiAl-LDHs and rGO@­Fe3O4-C, which delivers high specific capacity (201.3 F g–1) and exceptional energy density (71.7 Wh kg–1). The well-aligned Ni3S2@­rGO@­NiAl-LDHs could provide a promising conception constructing hierarchical structural materials in the area of supercapacitors.

In situ self-assembly of Ni3S2/MnS/CuS/reduced graphene composite on nickel foam for high power supercapacitors

“…36 C 1s peak can be tted into three Gaussian peaks centered at 284.6 eV, 286.0 eV and 288.6 eV, which are attributed to C]C, alkyl C-C, and O]C-O, respectively. [36][37][38][39]…”

“…Ni 3 S 2 /MnS/CuS@rGO displays more intense current density than Ni 3 S 2 /MnS/CuS@rGO and Ni 3 S 2 /MnS@rGO, suggesting enhanced activity and specic capacitance. 37 As shown in Fig. 7b, the redox peak in the CV curve may be correlated with the redox reaction between M 2+ and M 3+ (M represents Ni, Cu and Mn elements), as expressed by eqn (6)-(9).…”

Recent Progress in Two‐Dimensional Layered Double Hydroxides and Their Derivatives for Supercapacitors

“…The composite demonstrateda nu ltrahighs pecific capacitance of 2520 Fg À1 at 2Ag À1 ,g ood rate capability,a nd excellent cycling stability, [149] and was superior to those of the individual CuCo 2 S 4 NRAs and LDH. [76] Ni 3 S 2 and Co 9 S 8 have also been selected for combination with LDH to form composite-typee lectrode materials, examples of which are Ni 3 S 2 @rGO@NiAl LDHs nanoarrays [15] and NiCo LDH/Co 9 S 8 [150] .Y ilmaz et al employed ZIF-67 (a type of MOF) as the sacrificial template to synthesize NiCo LDH and NiCo LDH/Co 9 S 8 composites. [150a] The two composites exhibit the respective hollow and porouss tructures with al arge specific surfacea rea.…”

“…[12] In addition, M + and M 4 + ions can also be introduced to extendt he range of LDHs, such as LiAl LDH [13] and NiTiL DH. [14] There are several processing techniques that have been developed to synthesize LDHs for applications in SCs, such as hydrothermal, [15] electrodeposition, [16] chemical exfoliation and self-assembly, [17] and templating methods. [18] The LDHs thus-developedh aveb een studied for their performance as electrode materials in energy storage, in which they can offer the following advantages:1 )LDHs with al amellar structure and grown High-performance supercapacitors have attracted great attention due to their high power, fast charging/discharging, long lifetime, and high safety.H owever,t he generally low energy density and overall device performance of supercapacitors limit their applications.I nr ecent years, the design of rational electrode materials has provent ob ea ne ffective pathway to improvet he capacitive performances of supercapacitors.…”

Hydrothermal synthesis of cobalt telluride nanorods for a high performance hybrid asymmetric supercapacitor

“…3,4 Supercapacitors, also known as ultracapacitors, have drawn a great interest in recent years because of their high power performance, fast charge/discharge ability, long cycle life and low cost. [5][6][7][8][9][10][11] Commercial-based symmetric supercapacitors in non-aqueous electrolytes have delivered high-power densities in the range of 12-14 kW kg À1 with energy densities of 4-6 W h kg À1 . So, the progress of supercapacitors continues mostly towards the development of high energy and low-cost nanostructured electrode materials.…”