High-efficiency super capacitors based on hetero-structured α–MnO2 nanorods (original) (raw)
Related papers
2016
MnO2 is considered as a candid material for supercapacitor applications owing to its varied oxidation states, environmental friendliness and low cost. α-MnO2 nanorods is synthesized by a facile hydrothermal method and is characterized by X-ray Diffraction, Field Emission Scanning Electron Microscopy, gas adsorption studies, cyclic voltammetry, Galvanostatic charge-discharge studies and Electrochemical impedance spectroscopy. The α-MnO2 demonstrated a promising specific capacitance of ~310 F g-1 at a current density of 1 A g-1 with lower contact resistance in 3M LiOH
2021
Mn2O3 is a significant candidate for various applications. In the present work, the Mn2O3 nanorod arrays have been successfully prepared through facile sonochemical method with the aid of cetyl trimethyl ammonium bromide (CTAB) template. The crystalline phase and bonding properties have ben confirmed through X-ray diffraction analysis (XRD) and Fourier transform infrared (FTIR) spectroscopic analysis. The electrochemical properties were analysed through various techniques such as cyclic voltammetric and galvanostatic charge/discharge analysis. Interestingly, cyclic voltammetric (CV) curves confirms the electric double layer capacitor-based charge storage mechanism and it render the maximum specific capacitance of 647 Fg-1 at a scan rate 5 mVs-1 whereas the galvanostatic charge/discharge studies offer the specific capacitance of 656 Fg-1 at a current density of 1 Ag-1. The Mn2O3 nanorod arrays provide the maximum energy and power densities of 91.1 Wh Kg-1 and 14985 Wkg-1 respectively...
Electrochemical characteristics of two-dimensional nano-structured MnO2 for symmetric supercapacitor
Electrochimica Acta, 2013
Manganese oxide (MnO 2 ) powders with various nano structures were prepared using MnSO 4 as a precursor through hydrothermal method. Manganese oxides with needles, rods and flakes structure were formed depending on oxidizer used. The flakes-shaped MnO 2 exhibited the higher capacitance values than other structures, both in aqueous and organic electrolytes. The charge storage mechanism observed in aqueous electrolyte is mixed type of charge insertion-extraction and surface adsorption mechanism while that in organic electrolyte is insertion-extraction. The higher specific capacitance of 342 F g −1 in NaOH, 429 F g −1 in LiClO 4 and 455 F g −1 in LiPF 6 was observed for the flakes-shaped MnO 2 electrode.
Studies on MnO2 Nanorods and Their Application for Supercapacitor
Current Nanomaterials, 2017
Background: Recently, manganese dioxide (MnO 2) has attracted renewed attention of investigators. This is primarily due to its low cost, making it a potential material for various applications. Objective: The goal of the present work was to synthesize MnO 2 nanorods and study their optical and electrochemical properties. Method: The method involves refluxing of potassium permanganate (KMnO 4) and manganese chloride (Mncl 2) mixture in isopropyl alcohol (IPA)-water system. The surface morphology, vibrational response and structural parameters were characterized using field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman Spectroscopy, Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA) and BET surface area measurements. The optical properties of the synthesized material were investigated using PL and UV-Vis. Spectroscopy. Electrochemical properties of resulting product (as an electrode) were studied in two-electrode cell assembly, employing galvanostatic charge/discharge (GCD), electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV) techniques. Results: FESEM and TEM images show that material is in the form of nanorods. XRD analysis showed the tetragonal structure of synthesized product. Thermal stability up to 400 °C has been observed for the sample. The BET analysis of the sample showed the existence of large and small pores. A direct band-gap of 4.1 eV was observed. Specific capacitance of value 108.2 F g-1 was measured for 1 M Na 2 SO 4 electrolyte solution, at current density of 1 mA cm-2. Conclusion: MnO 2 nanorods were successfully prepared using chemical refluxing technique. The electrochemical studies show that MnO 2 can be profitably used for energy storage applications.
International Journal of Electrochemical Science, 2018
High purity α-MnO 2 rectangular nanowires are synthesized by a facile one-step hydrothermal method. The morphology and composition of α-MnO 2 nanowires are characterized by X-ray diffraction, energy-dispersive X-ray spectroscopy (EDX), Field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectral techniques. The electrochemical properties of α-MnO 2 nanowires have been studied as electrode material for supercapacitors. The α-MnO 2 nanowires exhibit a high specific capacitance of 362 Fg-1 at a current density of 1.0 Ag-1 with a good cycling stability (maintained 83% after 5000 cycles). These results indicate its promising applications as a high-performance electrode material for electrochemical energy storage.
Journal of Materials Science: Materials in Electronics, 2016
A new approach has been proposed for the preparation of nanostructured a-MnO 2. The method is based on the galvanostatic cathodic electrodeposition of the product from a nitrate bath under a direct current mode at a current density of 0.1 mA cm-2. The intermediate product deposited in this stage is next thermally treated at 300°C for 3 h. To evaluate the properties of the final product, it was characterized by XRD and FTIR so as to gain information on its phase composition (which was found to be mainly a-MnO 2) and SEM to gain information on its morphology (which was found to be nanospheres with secondary porous wall-like nanostructures). Additional electrochemical experiments on the product through cyclic voltammetry and charge-discharge tests revealed it to be capable of delivering high specific capacitance of 280 F g-1 , further its outstandingly long-term cycling stability which was only diminished to 95.4 % of the initial value after 1000 discharge cycles.
Diamond and Related Materials, 2019
The fabrication of energy storage devices with lowering the cost and improving the performance has always been the need for society. Therefore, supercapacitors with special features such as lightweight , easy portability and remarkable charging/discharging rate capability have widely been studied in the literature. In the present work, In-situ carbon coated manganese oxide nanorods (ISCC-MnO 2 NRs) have been studied for the supercapacitor application. ISCC-MnO 2 NRs were prepared by slip casting method followed by annealing at 1200°C. During heat treatment, sucrose has transformed into conducting carbon and coated on the surface of MnO 2. ISCC-MnO 2 NRs were examined by FEG-SEM, FEG-TEM, XRD, FT-IR, BET and Raman spectroscopy. The measurement of the electrochemical properties of the material was carried out in the two-electrode configuration using 1 M Na 2 SO 4 aqueous solution as an electrolyte. The specific capacitance of ISCC-MnO 2 NRs was found to be 28.24 F/g at the current density of 1 A g −1 with energy density of 0.98 Wh/kg. This work suggests ISCC-MnO 2 NRs may be a promising electrode material for the supercapacitor.
Thin Solid Films, 2017
Pulsed base (OH −) electrogeneration was applied to the cathodic electrodeposition of manganese oxide from chloride bath for the first time, and Mn 3 O 4 nanorods were prepared. The deposition experiments were performed under a pulse current mode in a typical on-times and off-times (t on = 10 ms and t off = 50 ms) at a peak current density of 1 mA cm −2 (I a = 1 mA cm −2). The structural characterizations with XRD and FTIR revealed that the prepared sample is composed of tetragonal crystal phase of Mn 3 O 4. Morphological evaluations by SEM further proved that the prepared Mn 3 O 4 is made up of large scale and vertically aligned one-dimensional (1D) nanorods with uniform shapes and an average diameter of 50 nm. The electrochemical measurements through cyclic voltammetry (CV) and charge-discharge techniques revealed that the prepared Mn 3 O 4 nanorods have an excellent capacitive behavior, with the specific capacitances as high as 321, 292, 264, 222, 187 and 132 F g −1 at the scan rates of 2, 5, 10, 25, 50 and 100 mV s −1 , respectively. The excellent long-term cycling stabilities of 91.7%, 83.4%, and 75.7% were also observed after 1000 charge-discharge cycles at the current densities of 1, 5 and 10 A g −1 , respectively.
beta phase manganese dioxide nanorods Synthesis and characterization for supercapacitor applications
arXiv: Materials Science, 2015
Manganese dioxide nanorods were synthesized using novel solution route. The phase and microstructure of synthesized materials were identified using X ray diffraction, scanning electron and transmission electron microscopic measurements. The material crystallizes into beta crystallographic phase and consists of nanorods of diameter in the range of about 10-14 nm and length about 50 nm. The Fourier Transform Infrared (FTIR) spectroscopic and thermogravimetric analysis (TGA) measurements were carried out to understand the materials microscopic and thermal properties. The material exhibits characteristic Mn O vibrational frequencies, confirming the phase purity of material. The electrochemical performance of beta MnO2 nanorods was evaluated using cyclic voltammetry and galvanostatic charge and discharge measurements using inhouse developed supercapacitor device assembly. We observed about 125 F per g specific capacitance for beta MnO2 nanorods electrode materials.
International Journal of Scientific Research in Science and Technology, 2021
Mn3O4 and its composite nanomaterials have become promising candidate as an electrode for supercapacitor devices, because of its low cost, non-toxicity, large abundance, high porosity and high capacitance values in aqueous electrolyte. Here, we systematically summarized the impact of different morphologies of Mn3O4 and its composite nanomaterials on supercapacitive performance. Many researchers synthesized various Mn3O4 and its composite nanomaterials of exceptional properties and different morphologies for energy storage. This article reviews recent efforts and developments in synthesis methods Mn3O4 and its composite nanomaterials as an electrode material in supercapacitor.