Design of NiO Flakes@CoMoO4 Nanosheets Core-Shell Architecture on Ni Foam for High-Performance Supercapacitors

Abstract

As typical electrode materials for supercapacitors, low specific capacitance and insufficient cycling stability of transition metal oxides (TMOs) are still the problems that need to be solved. Design of core-shell structure is considered as an effective method for preparation of high-performance electrode materials. In this work, NiO flakes@CoMoO 4 nanosheets/Ni foam (NiO flakes@CoMoO 4 NSs/NF) core-shell architecture was constructed by a two-step hydrothermal method. Interestingly, the CoMoO 4 NSs are vertically grown on the surface of NiO flakes, forming a two-dimensional (2D) branched core-shell structure. The porous core-shell architecture has relatively high surface area, effective ions channels, and abundant redox sites, resulting in excellent electrochemical performance. As a positive electrode for supercapacitors, NiO flakes@CoMoO 4 NSs/NF core-shell architecture exhibits excellent capacitive performance in terms of high specific capacitance (1097 F/g at 1 A/g) and outstanding cycling stability (97.5% after 2000 circles). The assembled asymmetric supercapacitor (ASC) of NiO flakes@CoMoO 4 NSs/NF//active carbon (AC)/NF possesses a maximum energy density of 25.8 Wh/kg at power density of 894.7 W/kg. The results demonstrate that NiO flakes@CoMoO 4 NSs/NF electrode displays potential applications in supercapacitors and the design of 2D branched core-shell architecture paves an ideal way to obtain high-performance TMOs electrodes. Electronic supplementary material The online version of this article (10.1186/s11671-019-3054-3) contains supplementary material, which is available to authorized users.

Eco-Friendly Synthesis of Cobalt Molybdenum Hydroxide 3d Nanostructures on Carbon Fabric Coupled with Cherry Flower Waste-Derived Activated Carbon for Quasi-Solid-State Flexible Asymmetric Supercapacitors

“…The faradaic reaction in the CMOH arrays during the respective anodic and cathodic cycles gave rise to the prominent oxidation and reduction peaks. The corresponding faradaic reactions that occur in the CMOH nanoplate arrays can be summarized as follows The molybdenum present in the matrix does not take part in the chemical reaction but improves the conductivity of the cobalt molybdate and hence contributes to the greater capacity of the electrode. , Likewise, the GCD performance of the Ni/CC/CMOH-12 electrode can be seen in Figure B. The nonlinear nature of the GCD curves confirms the occurrence of faradaic reactions in the electrode material and supports the notions made earlier in the case of CV cycles.…”

Highly Synergistic Co3+ and Pyridinic‐N‐Rich Bifunctional Electrocatalyst for Ultra‐Low Energy‐Driven Effective Hydrogen Production and Urea Oxidation

“…For Co 3 O 4 @ NC/NiO, three small diffraction peaks are observed at 37.9° (111), 43.2° (200), and 63.6° (220), confirming the formation of NiO from Ni(OH) 2 as per JCPDS No. 65-2901 because the heat treatment led to the removal of H 2 O molecules and decomposition of Ni(OH) 2 [56,57] (Figure 3b). The heat treatment at 700 °C resulted in the Co-MOF-templated formation of Co 3 O 4 nanoparticles embedded with N-doped carbon on NiO; the diffraction peaks at 31.1° (220), 35.6° (311), and 66.3° (440) coincide with the XRD pattern of JCPDS Card no.…”

Metal–Organic-Framework-Derived N-, P-, and O-Codoped Nickel/Carbon Composites Homogeneously Decorated on Reduced Graphene Oxide for Energy Storage

“…The calculated capacities from the GCD curves showed a maximum energy density of 79.7 Wh kg –1 at a power density of 1275 W kg –1 and held up to an energy density of 20.9 Wh kg –1 even at a power density as high as 8500 W kg –1 . To evaluate the electrochemical performance of the as-fabricated ASC, a comparison was made with a few recently reported analogues (Figure e). − Ni/C/rGO-4//AC exhibited properties superior to those of reported composites, such as Ni x Co 1– x (OH) 2 //AC, NiO/rGO//AC, NiO/C/rGO//SCC, Ni­(OH) 2 /af-GQDs//EG, and NiO flakes@CoMoO 4 NSs/NF//AC/NF. Last but not least, the cycling performance of Ni/C/rGO-4//AC was assessed with 8000 GCD cycles and 83.7% capacitance retention was achieved, indicating an outstanding stability.…”