Regulating the Oxygen Vacancy and Electronic Structure of NiCo Layered Double Hydroxides by Molybdenum Doping for High-Power Hybrid Supercapacitors.

Operando leaching of pre-incorporated Al and mechanism in transition-metal hybrids on carbon substrates for enhanced charge storage

Hierarchical molybdenum disulfide nanosheet arrays stemmed from nickel-cobalt layered double hydroxide/carbon cloth for highly-efficient hydrogen evolution reaction

Plasmonic Au-NPs photodecorated on NiCoLDH nanosheets as a flexible SERS sensor for the real-time detection of fipronil

Selective electrocatalytic nitrobenzene-to-aniline reduction on nickel-cobalt layered double hydroxide via dual-site hydrogen atom transfer.

Electrochemical detection of carmoisine in the presence of tartrazine on the surface of screen printed graphite electrode modified with nickel-cobalt layered double hydroxide ultrathin nanosheets

Three dimensional hierarchical porous nickel cobalt layered double hydroxides (LDHs) and nitrogen doped activated biocarbon composites for high-performance asymmetric supercapacitor

Flexible energy storage devices have gained a wide concern in latest years owing to their portable and practical characteristics. However, the capacitance decay of flexible energy storage devices and short cycle life limit their development. To solve these problems, we develop a simple electrodeposition method to enhance the electrochemical activity and structural stability of the nickel cobalt layered double hydroxides (NiCoLDH) nanosheet arrays on carbon cloth (CC) by rational introduction of carbon quantum dots (CQD). Due to the induced effect and toughening effect of CQD, the obtained CQD modified NiCoLDH nanosheet arrays on CC electrode (CQD/NiCoLDH@CC) not only exposes more active sites of NiCoLDH nanosheets to improve their electrochemical capacity, but also makes their structure more stable to enhance their cycle life. The optimized electrode of CQD/NiCoLDH-3@CC can release a high specific capacitance of 1587.1 F g−1 at 1 A g−1 and maintain 1281.2 F g−1 at 20 A g−1, as well as good cycling stability with 60.1% capacitance retention after 10,000 cycles at 10 A g−1. The assembled flexible aqueous asymmetric CQD/NiCoLDH-3@CC//activated CC supercapacitor shows a high energy density of 0.37 mWh cm−2 with the power density of 3.79 mW cm−2 at 5 mA cm−2. This work provides new insight into the designing of pseudocapacitive materials for energy storage.

High mass-loading of nickel‑cobalt layered double hydroxide on 3D-printed electrode for cathode of asymmetric supercapacitor

Nickel-cobalt layered double hydroxides (NiCo-LDH) were successfully deposited on nickel foam by a facile hydrothermal method using polyvinyl pyrrolidone (PVP) as the structure-directing reagent. The effect of PVP on the morphology and electrochemical performance of binder-free NiCo-LDH electrode for supercapacitor were investigated in detail. The prepared NiCo-LDH presented good dispersivity and appeared different flower-like structure via the addition of PVP. Specially, the NiCo-LDH electrode using 1 g of PVP exhibited a superior performance with a high-specific capacity of 724.9 C g−1 at a current density of 1 A g−1 and 577.1 C g−1 at 10 A g−1. In addition, a hybrid supercapacitor (HSC) based on the optimized NiCo-LDH as positive electrode and activated carbon as negative electrode was assembled with 6 M KOH as the electrolyte. The HSC device can deliver an energy density of 32.3 Wh kg−1 at the power density of 387.1 W kg−1. Moreover, the HSC device exhibited a good cycling stability with a retention rate of 94.0% after 2000-cycle charge-discharge test at 3 A g−1.

Oxygen vacancy-rich flower-like nickel cobalt layered double hydroxides for supercapacitors with ultrahigh capacity

We demonstrated an efficient method for the fabrication of novel, flexible electrodes based on ZnO nanoflakes and nickel-cobalt layered double hydroxides (denoted as ZnONF/NiCoLDH) as a core-shell nanostructure on textile substrates for wearable energy storage devices. NiCoLDH coated ZnO nanowire (denoted as ZnONW/NiCoLDH) flexible electrodes are also prepared for comparison. As an electrode for supercapacitors, ZnONF/NiCoLDH exhibits a high specific capacitance of 1624 F g(-1), which is nearly 1.6 times greater than ZnONW/NiCoLDH counterparts. It also shows a maximum energy density of 48.32 W h kg(-1) at a power density of 27.53 kW kg(-1), and an excellent cycling stability with capacitance retention of 94% and a Coulombic efficiency of 93% over 2000 cycles. We believe that the superior performance of the ZnONF/NiCoLDH hybrids is due primarily to the large surface area of the nanoflake structure and the open spaces between nanoflakes, both of which provide a large space for the deposition of NiCoLDH, resulting in reduced internal resistance and improved capacitance performance. Our results are significant for the development of electrode materials for high-performance wearable energy storage devices.

Acetate anion-intercalated nickel-cobalt layered double hydroxide nanosheets supported on Ni foam for high-performance supercapacitors with excellent long-term cycling stability

Biomass-derived carbon dots regulating nickel cobalt layered double hydroxide from 2D nanosheets to 3D flower-like spheres as electrodes for enhanced asymmetric supercapacitors

MOF-derived AuNS/LDH with high adsorption ability for surface enhanced Raman spectroscopy detection

The oxygen evolution reaction (OER) at the anode is of prime importance in electrochemical water splitting. Recently, layered double hydroxide (LDH) has been considered as one of the most effective materials for OER catalysts which are prone to hydrolysis and oxidation under OER conditions. Metal-organic frameworks (MOFs) are new class of porous materials with high crystallinity and high internal surface area. Based on their properties, the design of LDH based on morphology-controlled MOFs is gaining increasing attention. In this study, we report a novel approach to fabricate hollow leaf-shaped iron doped nickel cobalt LDH (Fe-NiCoLDH) based on 2D leaf-shaped ZIF (ZIF-L). Iron doping played an important role to enhance the specific surface area as well as the pore structure, resulting in improvement of the OER performance. Among the investigated Fe concentrations (from 40 to 80 mg) in this study, Fe60-NiCo LDH showed the highest electrocatalyst performance for OER of 10 mA cm-2 at 253 mV as well as high stability for 20 h. The design of nanostructures such as leaf-shaped LDH has great potential in enhancing OER efficiency.