Enhanced electrochemical performance of 3‐D microporous nickel/nickel oxide nanoflakes for application in supercapacitors

Abstract

Increasing energy demands, depletion of fossil fuels, and environmental issues have impelled society to choose the pathways of renewable and clean energy, which motivated scientists and engineers to develop sustainable, renewable, and clean energy resources. However, the major challenge is the implementation of low-cost, flexible approaches and materials to fulfill the requirements of energy storage and conversion technologies, specifically those involving batteries and supercapacitors. In this context, herein, we demonstrate an integrated approach to realize three-dimensional (3-D) mesoporous nickel(Ni)/nickel oxide (NiO) nanostructures with enhanced performance for supercapacitor applications. Conformal deposition of NiO nanoflakes on 3-D mesoporous Ni onto inexpensive Cu substrates with large active surface area, providing easy ion accessibility through mesoporous channels and improving electron transport through interconnected nickel network. The 3-D mesoporous Ni/NiO nanoflakes exhibit excellent electrochemical performance, namely, areal capacitance of 720 mFcm −2 , energy density of 4 μWhcm −2 and power density of 2.5 mWcm −2 and a reasonable capacity retention for 5000 cycles. We believe that these results may provide a roadmap to further tune the conditions so as to engineer oxide architectures to derive enhanced energy performance of supercapacitor devices for practical applications.

Effect of Dy3+ and Tb3+ Rare-Earth Cation Co-Substitution on the Structure, Magnetic, and Magnetostrictive Properties of Ni-Co-Ferrites

“…Nickel ferrite (NiFe 2 O 4 ; NFO), which is one of the spinel ferrite families, finds interesting applications in numerous technologies, including the sensors for automotive and energy technologies. , NFO continues to draw the attention of the scientific and research community in view of its excellent properties, such as high electrical resistivity (greater than 10 9 Ω cm), low eddy current loss, notable physical and chemical stability, high Curie temperature ( T c = 585 °C), moderate saturation magnetization and coercivity, and good strain sensitivity at a lower magnetic field ( H ≤ 1000 Oe). ,, The structural, chemical, electronic, and magnetic properties make NFO and NFO-based materials quite attractive in many applications, such as in recording media, three-dimensional transformers, high-frequency devices, strain sensors, magnetic field sensors, magnetoelectrical sensors, and also biological applications. However, as to magnetostrictive characteristics, NFO exhibits a soft magnetic and low anisotropy with a magnetostriction measured in the range of −25 to −40 ppm at relatively low magnetic fields.…”

Germanium‐Functionalized 3D Microporous, Nanostructured Nickel–Nickel Oxides for Application in Asymmetric Supercapacitors

“…As presented and discussed in this paper, the 3D mesoporous GeNiO nanostructures exhibit excellent electrochemical performance when used as a positive electrode for asymmetric supercapacitor configuration. [35,36] The scanning electron microscope (SEM)-determined surface morphology of the Ge-NiO samples is shown in Figure 3. The data shown in Figure 3a,b is the surface morphology features of 3D-microporous Ni before and after annealing at 400 °C.…”