Electrochemical Properties Of Mn Research Articles

Suppressing the Jahn–Teller effect in Mn-based Prussian blue analogues by linear (N[dbnd]O) anions

Manganese-based Prussian blue analogues (PBAs) have been touted as a promising cathode material for sodium-ion batteries (SIBs) due to their low cost, long cycle life and high energy density. However, manganese-based PBAs perform poorly during cycling due to the Jahn-Teller effect. In this study, highly stable manganese nitrosylpentacyanoferrate (Mn[Fe(CN)5NO]) particles were synthesized using a simple hydrothermal method. The presence of nitroso group breaks the symmetry of the crystals to some extent, which is favorable to reduce the Jahn-Teller effect. Through experiments and DFT calculations, we confirm that the presence of linear (NO) anions reduces the lattice volume fluctuations of the samples during charging and discharging, thus contributing to the mitigation of the Jahn-Teller effect. The electrochemical properties of Mn[Fe(CN)5NO] were significantly improved compared to manganese hexacyanoferrate (MnFe[CN]6). Mn[Fe(CN)5NO] exhibited excellent sodium storage performance with an initial discharge capacity as high as 144.5 mAh/g at 20 mA g-1and capacity retention as high as 82.1 % after 400 cycles at 100 mA g−1. This Mn[Fe(CN)5NO] sample provides a promising cathode for sodium-ion batteries in large-scale energy storage systems.

Fabrication and electrochemical properties of Mn, N, and S co-doped carbon fiber composite bamboo-based woodceramics electrodes

Prepared in this study, Mn, N and S co-doped woodceramics electrodes (WC@Mn-N/S) were prepared using waste bamboo as the base material, carbon fiber as the reinforcement fiber, KMnO4 and CH4N2S as dopants and activators. Mechanical analysis revealed a 68 % increase in the flexural strength of the matrix material reinforced with carbon fibers. Scanning electron microscopy observation indicated that WC@Mn-N/S retained the original natural pore structure of bamboo. The specific surface area (BET) analysis revealed that WC@Mn-N/S exhibited a specific surface area of 861.7 m2/g, with its pore size structure mainly distributed in the range of 1.3–3.8 nm. Electrochemical performance tests showed that the introduction of Mn, N and S elements endowed the bamboo-based electrode with pseudocapacitance characteristics. Additionally, the synergistic effect between these three elements imparted pseudocapacitance to the electrode material. WC@Mn-N/S performent a specific capacitance of 615 F/g, at 0.2 A/g with excellent capacitance retention (99.4 % after 5000 cycles). In the practical assembled in symmetrical capacitor the material showed high power density 500 W/kg and energy density 57.9 Wh/kg, indicating its excellent electrochemical performance.

Effect of reducing agents on structural, morphological, optical and electrochemical properties of Mn2O3 nanoparticles by co-precipitation method

Abstract In this work, two different reducing agents namely sodium hydroxide and potassium hydroxide (NaOH and KMnO4) were used to synthesis of manganese oxide (Mn2O3) nanoparticles by the co-precipitation method and examined for the electrochemical applications. The as-prepared Mn2O3 nanoparticles using NaOH precursor, dried in a hot oven at 80 °C for 6 h (MN-1) and then annealed for 7 h at 600 °C (MN-2). Similarly, Mn2O3 nanoparticles were prepared using KMnO4 precursor, dried in a hot oven at 80 °C for 6 h (MK-1) and then annealed for 7 h at 450 °C (MK-2), respectively. The influences of reducing agents on structural, morphological and optical properties were investigated. The structural analysis revealed the prepared samples had tetragonal crystal structures with better crystallinity. FT-IR spectral analysis revealed the characteristic bonds of Mn–O–Mn were observed in the region of 486–573 cm−1. The FE-SEM and HR-TEM images showed coral-like and nanorod structures for samples MN-2 and MK-2, with exhibited lattice value of 0.27 nm related to the (222) plane. The presence of the elements manganese (Mn) and oxygen (O) was confirmed by EDAX mapping. The XPS study confirmed that the oxidation state of the prepared samples was +2. The UV-Vis spectra suggested that the adsorption edge was blue-shifted compared to the sample MN-2. Cyclic voltammetry (CV) and galvanostatic charge–discharge experiments demonstrated that charge storage in Mn2O3 exhibited faradic-dominated capacitive behavior. MN-2 nanorod structures were obtained at excellent specific capacitance value of 196 F g−1 compared to MK-2 nanoparticles. Based on this study, Mn2O3 nanoparticles was recommended as exceptional electrode materials for efficient supercapacitor applications due to its superior electrical conductivity, large surface area and redox properties.

Effect of Mn:(CuO/Cu(OH)2) Electrodes for Supercapacitors Application

In the present study, we report structural and electrochemical properties of Mn:(CuO/Cu(OH) 2 ) electrodes were investigable made-up on stainless steel via surfactant-free and inexpensive successive ionic layer adsorption and reaction (SILAR) method. Further, these CuO(CuOH) 2 and 3% Mn:CuO(CuOH) 2 electrodes exhibits outstanding surface properties like uniform growth on surface, high surface area and uniform pore size distribution of pure and doped CuO samples. The electrochemical properties of pure and 3% Mn doped (CuO(CuOH) 2 ) nanostructure have been investigated by cyclic voltammetry, charge discharge. The electrochemical studies of the pure and 3% Mn doped (CuO(CuOH) 2 ) samples show evident influence of surface properties on the pseudo capacitance performance. The maximum specific capacitances of nanoflowers like CuO electrodes are found to be 597 Fg −1 , respectively at 5 mV s −1 scan rate. Present investigation suggests the inexpensive SILAR move toward for fine modification surface properties of 3% Mn:(CuO(CuOH) 2 ) materials for energy storage applications. © 2015 American Scientific Publishers. All rights reserved.