ZIF-67 MOF-Derived Mn3O4 @ N-Doped C as a Supercapacitor Electrode in Different Alkaline Media.

Transition-metal oxide has been identified as an auspicious material for supercapacitors due to its exceptional capacity. The inadequate electrochemical characteristics, such as prolonged cycle stability, can be ascribed to factors, such as low electrical conductivity, sluggish reaction kinetics, and a deficiency of active sites. The transition-metal oxides derived from the MOF materials offer a larger surface area with enriched active sites and a faster reaction rate along with good electrical conductivity. The manganese (Mn)-based metal-organic framework (MOF)-derived materials were produced using the pyrolysis method. Zeolitic imidazolate frameworks (ZIF-67) were fabricated in water at ambient temperature with the aid of triethylamine. Multiple techniques were used to examine the characteristics of the fabricated electrode materials. The influence of the electrolyte on the electrochemical activity of the Mn3O4@N-doped C electrode materials was determined in KOH, NaOH, and LiOH. For manufacturing of "Mn3O4@N-doped C", ZIF-67 was used as a precursor. The capacitive performance of the Mn3O4@N-doped C electrode increased as a result of nitrogen-doped carbon; after 5000th cycles, the electrode retained an excellent rate capability and a high specific capacitance (Cs) of 980 F g-1 at 1 A g-1 under 2.0 KOH electrolyte in a three electrode system. The carbonized manganese oxide displays also had a high Cs of 686 F g-1 in two electrode systems in 2.0 M KOH. Materials made from MOFs show promise as capacitive materials for applications in energy conversion storage owing to their straightforward synthesis and strong electrochemical performance.

MnO2 Nanoparticles Anchored Multi Walled Carbon Nanotubes as Potential Anode Materials for Lithium Ion Batteries.

Herein, we report a facile hydrothermal synthesis of MnO2 nanoparticles anchored multi walled carbon nanotubes (MnO2@MWCNTs) as potential anode materials for lithium-ion (Li-ion) batteries. The prepared MnO2@MWCNTs were characterized by several techniques which confirmed the formation of MnO2 nanoparticles anchored MWCNTs. The X-ray diffraction and Raman-scattering analyses of the prepared material further revealed the effective synthesis of MnO2@MWCNTs. The fabricated Li-ion battery based on MnO2@MWCNTs exhibited a reversible capacity of ~823 mAhg-1 at a current density of 100 mAg-1 for the first cycle, and delivered a capacity of ~421 mAhg-1 for the 60 cycles. The coulombic efficiency was found to be ~100% which showed excellent reversible charge-discharge behavior. The outstanding performance of the MnO2@MWCNTs anode for the Li-ion battery can be attributed to the distinctive morphology of the MnO2 nanoparticles anchored MWCNTs that facilitated the fast transport of lithium ions and electrons and accommodated a broad volume change during the cycles of charge/discharge.