The growth of nickel-manganese and cobalt-manganese layered double hydroxides on reduced graphene oxide for supercapacitor

High performance asymmetric supercapacitor based on Cobalt Nickle Iron-layered double hydroxide/carbon nanofibres and activated carbon

A novel Cobalt Nickle Iron-layered double hydroxide/carbon nanofibres (CoNiFe-LDH/CNFs-0.5) composite was successfully fabricated through an easy in situ growth approach. The morphology and composition of the obtained materials were systematically investigated. When the two derived materials were used for supercapacitor electrodes, the CoNiFe-LDH/CNFs-0.5 composite displayed high specific surface area (114.2 m² g⁻¹), specific capacitance (1203 F g⁻¹ at 1 A g⁻¹) and rate capability (77.1% from 1 A g⁻¹ to 10 A g⁻¹), which were considerably higher than those of pure CoNiFe-LDH. Moreover, the specific capacitance of CoNiFe-LDH/CNFs-0.5 composite remained at 94.4% after 1000 cycles at 20 A g⁻¹, suggesting excellent long-time cycle life. The asymmetric supercapacitor based on CoNiFe-LDH/CNFs-0.5 as a positive electrode and activated carbon as a negative electrode was manufactured and it exhibited a specific capacitance of 84.9 F g⁻¹ at 1 A g⁻¹ and a high energy density of 30.2 W h kg⁻¹. More importantly, this device showed long-term cycling stability, with 82.7% capacity retention after 2000 cycles at 10 A g⁻¹. Thus, this composite with outstanding electrochemical performance could be a promising electrode material for supercapacitors.

NiMn layered double hydroxides as efficient electrocatalysts for the oxygen evolution reaction and their application in rechargeable Zn-air batteries

High performance catalysts for the oxygen evolution reaction (OER) are in demand to improve the re-chargeability of Zn-air batteries. In this work, atomically dispersed NiMn layered double hydroxides are prepared via simple hydrothermal synthesis and tested as the OER catalyst in rechargeable Zn-air batteries. NiMn layered double hydroxides with the optimized Ni : Mn molar feeding ratio have good crystallinity, big interlayer spacing, and large surface area, which are beneficial to enhance their catalytic activity. They are highly active and stable during the OER, showing an overpotential of 0.35 V, a Tafel slope of 40 mV dec^-1, and remarkable stability during 16 h of a chronopotentiometry test. Rechargeable Zn-air batteries with NiMn layered double hydroxides as the OER catalyst exhibit a low charge voltage of ≈2 V which is stable for up to 200 cycles. This study illustrates a platform to enhance the catalytic activity of the OER catalyst via fine-tuning the composition and physical properties of the materials and their application for rechargeable metal-air batteries.

Electrochemical properties of NiCoO2 synthesized by hydrothermal method

NiCoO₂ microspheres were successfully synthesized via an easy hydrothermal method, followed by an annealing process at 350 °C under a nitrogen atmosphere.

Synthesis of Ni/Co/Al-layered triple hydroxide@brominated graphene hybrid on nickel foam as electrode material for high-performance supercapacitors

The determined need for a sustainable energy economy has evoked the increasing interest of researchers concerning the discovery of smart material designs of layered double hydroxide (LDH) nanocomposites for energy-based applications.

Low-cost and high-performance of a vertically grown 3D Ni–Fe layered double hydroxide/graphene aerogel supercapacitor electrode material

A three-dimensional Ni–Fe layered double hydroxide/graphene hybrid aerogel (Ni–Fe LDH/GHA) was synthesised and used as a high performance supercapacitor electrode material.

A comparative study of Ni–Mn layered double hydroxide/carbon composites with different morphologies for supercapacitors

A variety of carbon materials varying from 0D to 2D, i.e. 0D nanoparticles, 1D carbon nanotubes (CNTs) and 2D reduced graphene oxide (rGO) are selected to in situ combine with Ni–Mn layered double hydroxide (LDH) to prepare electrode materials for supercapacitors.