Growth of Ni3Se2 nanosheets on Ni foam for asymmetric supercapacitors

One-Dimensional NiSe–Se Hollow Nanotubular Architecture as a Binder-Free Cathode with Enhanced Redox Reactions for High-Performance Hybrid Supercapacitors

“…34 The fabricated NiSe−Se@Ni foam electrode exhibited specific capacitances of 2447.46, 1745, and 1200.7 F g −1 at current densities of 1, 2, and 3 A g −1 , respectively. The specific capacitance of the NiSe−Se@Ni foam electrode was higher than most other electrode materials reported in the past research, including NiSe solid spheres (492 F g −1 at 0.5 A g −1 ), 13 NiSe 2 hexapods (75 F g −1 at 1 mA cm −2 ), 35 NiSe 2 hollow nanospheres (341 F g −1 at 1 A g −1 ), 16 Ni 3 Se 2 nanosheets (854 F g −1 at 1 A g −1 ), 36 NiSe 2 @carbon fibers (1058.5 F g −1 at 2 A g −1 ), 37 NiCoSe nanosheets (742.4 F g −1 at 1 mA cm −2 ), 38 Ni 0.85 Se nanoparticles (114.6 mA h g −1 at 1 A g −1 ), 39 bimetallic NiCoSe (873 F g −1 at 1 A g −1 ), 40 NiCoSe spheres (827.9 F/g at 1 A/g), 17 NiSe0.85Se@MoSe2 (774 F/g at 1 A/g), 18 hollow NiCoSe-complex spheres (827.9 F g −1 at 1 A g −1 ), 17 NiCoSe nanoparticles (602.6 C g −1 at 1 A g −1 ), 41 NiSe 2 @Ni(OH) 2 (2212 F g −1 at mA cm −2 ), 42 Ni 3 Se 2 nanosheets on Ni foam (854 F g −1 at 1 A g −1 ), 36 NiSe 2 nanoarrays (1058.5 F g −1 at 2 A g −1 ), 37 and polyhedral NiCoSe 2 (300.2 F g −1 at 1 A g −1 ). 43 The high capacitance value of the proposed foam composite could be due to the thin porous 1D nanotubes grown on highly conducting three-dimensional (3D) Ni foam, which not only acted as nanoreservoirs for the storage and consistent supply of the electrolyte but also increased the rate of ion diffusion across the electrode surface.…”

NiF2 Nanorod Arrays for Supercapattery Applications

“…At 1, 5, 10, 15, and 25 mV s –1 scan rates, the areal specific capacitances (ASC) of the NiF 2 @Ni NA were respectively 51, 13, 9, 7, and 5 F cm –2 , which is ascribed to a reduction in the migration speed of ions for redox reactions, as at higher scan rates and accessibility of inner active sites is limited. , Because of a high surface area and a mechanically robust adhesion with lowered interfacial resistance to the underlying Ni, the self-grown mesoporous NiF 2 @Ni NA offers more accessible sites for redox reactions compared to polished Ni and similar nanostructured electrode materials of various composition and morphologies on Ni (see Table S1 of the Supporting Information). The inner/outer surface contributions to the ASC of NiF 2 @Ni NA compared to Ni are shown in inset of Figure a, where we consistently observe a higher amount of charge (typically a factor of ∼2× greater) is stored on the NiF 2 @Ni NA (for more details see the Supporting Information Figure S3a,b). − For both electrodes, at the initial potential of 0.2 V (vs Hg/HgO), the slope of 0.2 increased to 0.45 and reached 0.5 (indicating a diffusion-limited intercalative process) at potentials >0.4–0.5 V, indicating that NiF 2 @Ni NA behaves as a battery-type material (see Figure S3c,d for more details) . Taken together, the intercalation capacitive contribution was more than 90% in both electrodes, signifying its dominance in the ASC performance (Figure S3e–h, Supporting Information) with higher values obtained for the NiF 2 nanorod coating.…”

“…Developing abundant, robust, scalable, and greener chemical routes for metal-oxides/hydroxides/carbides/nitrides/phosphides/layered double hydroxides etc., has seen some promising developments for both battery electrode materials. , We provide a comparison of recently published data on ECS application using Ni­(OH) 2 , NiO, Ni x S y , NiTe, NiSe, and so forth, electrodes, developed by simpler chemical reduction or electroless methods among others, − in Figure , with further details on performance (capacitance) and related data provided in the Supporting Information, Table S1. Electrode materials grown by displacement, reduction, or electroless processes, for example, with high surface area and a strong mechanical adhesion to the underlying substrate material tend to offer better performance than metal salt or binder inspired hydrothermally/chemically grown electrodes, although much of the improvement tends to be a geometrical enhancement, rather than an intrinsic one.…”

Emergence of Ni‐Based Chalcogenides (S and Se) for Clean Energy Conversion and Storage

“…The assembled HSC delivered moderate energy density of 23.3 W h kg −1 at a power density of 398.1 W kg −1 . [ 155 ] To further improve the electrochemical performance, a composite of N‐GNTs@NiCoSe 2 /Ni 3 Se 2 nanotubes on graphene was prepared. The material achieved a capacitance of 1308 F g −1 at 1 A g −1 .…”