Design of manganese dioxide for supercapacitors and zinc-ion batteries: similarities and differences (original) (raw)
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Manganese oxide synthesized from spent Zn-C battery for supercapacitor electrode application
Scientific Reports
Manganese oxide (Mn 3 o 4) nanomaterials have promising potential to be used as supercapacitor electrode materials due to its high energy storage performance and environmental compatibility. Besides, every year huge volume of waste batteries including Zn-C battery ends up in landfill, which aggravates the burden of waste disposal in landfill and creates environmental and health threat. Thus, transformation of waste battery back into energy application, is of great significance for sustainable strategies. Compared with complex chemical routes which mostly apply toxic acids to recover materials from Zn-C battery, this study establishes the recovery of Mn 3 o 4 particles via thermal route within 900 °C under controlled atmosphere. Synthesized Mn 3 o 4 were confirmed by XRD, EDS, FTIR, XPS and Raman analysis and FESEM micrographs confirmed the coexistence of spherical and cubic Mn 3 o 4 particles. Mn 3 o 4 electrode derived from waste Zn-C battery demonstrate compatible electrochemical performance with standard materials and conventional synthesis techniques. Mn 3 o 4 electrode exhibited highest capacitance value of 125 Fg −1 at 5 mVs −1 scan rate. the stability of the electrode showed good retention in discharge and charge capacity by about 80% after 2100 cycles. This study demonstrates that waste Zn-C battery can be further utilized for energy storage application, providing sustainable and economic benefits. Supercapacitor become more attractive and efficient energy storage and conversion devices than batteries due to high specific power, long life cycle and fast charge-discharge rate 1. Hence, supercapacitors are undergoing rapid development with widespread application in automobiles, electronics and in industries 1. Supercapacitors mainly consist of electrodes, current collectors, electrolyte and a spacer but electrodes are the key element of supercapacitor's performance 1-3. In general supercapacitor store energy via either electrical double layer capacitance (EDLC) principle or the pseudo-capacitance mechanism. Energy density in EDLC is managed by the electrostatic capability of the absorbing electrolytes (anions, cations), by active materials embedded within electrodes and therefore carbon materials such as, activated carbon, carbon nanotubes etc. with high surface area are used. Besides, in pseudo-capacitance mechanism, energy density is governed by reversible redox interactions of the active materials as electrode and generally transition metal oxides and conducting polymers are used as active materials 1,4,5. Nanostructured metal oxides as electrode material, have attracted attention due to design flexibility, low resistance and high specific capacitance 6. Manganese oxide (MnO x) has a wide range of applications including catalysis, electrochemical materials, high-density magnetic storage media etc. Recently, MnOx materials including Mn 3 O 4 were substantially reported as supercapacitor electrode materials due to its environmental compatibility, low cost and good electrochemical performance compared to other oxides like ruthenium oxide 7. Mn 3 O 4 materials for different application covers a wide range of synthesis routes including reduction, thermal decomposition, coprecipitation, hydrothermal, sol-gel 8-10 etc. using reagent grade materials. Besides, Mn 3 O 4 /Mn 3 O 4-composite materials for supercapacitor application includes electrostatic spray deposition, hydrothermal synthesis etc. techniques 11-13. However, the synthesis routes and preparation techniques are complex and may use toxic acid. The use of waste carbonaceous materials like bio-waste, polymers etc. have been reported for energy storage applications, but metal oxides from waste were ignored. To best our knowledge, no study has reported Mn 3 O 4 from
Applied Sciences
MnO2 is the most favorable material in power storage due to its technological significance and potential applications in pseudocapacitance (due to various oxidative states allowing efficient charge transfer to meet energy demands), where its properties are considerably influenced by its structure and surface morphology. In the present study, a facile hydrothermal route was used to produce different phases of MnO2 (α, β, and γ) with different morphologies. The electrochemical performance of the synthesized phases was studied in aqueous sodium sulfate as an electrolyte. X-ray diffraction, UV–Vis spectroscopy, and Fourier-transform infrared spectroscopy were used to characterize the synthesized material. The surface morphology and topography were examined using field-emission scanning electron microscopy. The direct band gap of α-, β-, and γ-MnO2 was found to be 1.86 eV, 1.08 eV, and 1.68 eV, lying in the semiconducting range, further enhancing the electrochemical performance. It was f...
Electrochemical Performance of MnO2 for Energy Storage Supercapacitors in Solid-State Design
2018
In this work, solid-state supercapacitors with ionic liquid gel polymer electrolyte and MnO 2 electrodes were fabricated and characterized. The MnO 2 electrode was prepared by ultra-short pulsed electrochemical deposition over flexible graphite substrates. The ionic liquid gel polymer electrolyte was prepared by immobilizing ionic liquid BMIBF 4 with PVdF-HFP. The electrochemical performance of the solid-state supercapacitor was evaluated by three electrochemical characterization techniques including cyclic voltammetry (CV), galvanostatic charge-discharge (CD), and electrochemical impedance spectroscopy (EIS). CV measurements were conducted at two different voltage ranges showing typical capacitive character evidenced from the nearly rectangular shape. Charge-discharge analysis showed specific energy and specific power values of 1.27 Wh kg -1 and 0.292 kW kg -1 , respectively. EIS analysis confirmed the capacitive character of the device and produced an areal capacitance density of ...
Orange by-products e.g. orange peel and the extract of orange juice are used as sources for biological anti-oxidants such as ascorbic acid, flavonoids, phenolic compounds and pectins. In this study these antioxidants were successfully used to prepare nanosized materials of α-MnO 2 by cost effective and eco-friendly green chemistry method. The prepared oxides of MnO 2 which have unique properties as a storage cathode material were tested as a pseudocapacitor electrode materials in this study. X-ray powder diffraction (XRD) confirmed the structure of α-MnO 2 for the prepared samples. Thermal behavior of prepared oxides was tested using thermo-gravimetric analysis (TGA). Transmission electron microscopy (TEM) showed the nanosized nature of the prepared oxides. N 2-adsorption-desorption isotherms and pore-size distributions of prepared oxides showed that the surface areas are 5.63 and 8.40 m 2. g −1 for sample prepared from the extract of orange juice (OJ-MnO 2) and that prepared from the extract of orange peel (OP-MnO 2), respectively. Better electrochemical properties are obtained for OP-MnO 2 , the capacitance of OP-MnO 2 (139 F/g) is more than two times and half that obtained for OJ-MnO 2 (50 F/g) at the current density 0.5 A/g.
2024
Safety issues of energy storage devices in daily life are receiving growing attention, together with resources and environmental concerns. Aqueous zinc ion batteries (AZIBs) have emerged as promising alternatives for extensive energy storage due to their ultra-high capacity, safety, and eco-friendliness. Manganese-based compounds are key to the functioning of AZIBs as the cathode materials thanks to their high operating voltage, substantial charge storage capacity, and eco-friendly characteristics. Despite these advantages, the development of high-performance Mn-based cathodes still faces the critical challenges of structural instability, manganese dissolution, and the relatively low conductivity. Primarily, the charge storage mechanism of manganese-based AZIBs is complex and subject to debate. In view of the above, this review focuses on the mostly investigated MnO2-based cathodes and comprehensively outlines the charge storage mechanisms of MnO2-based AZIBs. Current optimization strategies are systematically summarized and discussed. At last, the perspectives on elucidating advancing MnO2 cathodes are provided from the mechanistic, synthetic, and application-oriented aspects.
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.
Manganese oxides are important materials with a variety of applications in different fields such as chemical sensing devices, magnetic devices, field-emission devices, catalysis, ion-sieves, rechargeable batteries, hydrogen storage media and microelectronics. To open up new applications of manganese oxides, novel morphologies or nanostructures are required to be developed. Via sol-gel and anodic electrodeposition methods, M (Co, Fe) doped manganese oxides were prepared. On the other hand, nanostructured (nanoparticles, nanorods and hollow nanotubes) manganese oxides were synthesized via a process including a chemical reaction with carbon nanotubes (CNTs) templates followed by heat treatment. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), cyclic voltammetry (CV) and impedance spectroscopy (EIS) were used for characterization of the prepared materials. The influence of chemical reaction conditions, heat treatment and template present on the morphology, structure, chemical and electrochemical properties of the prepared materials were investigated. Chronopotentiometry (CP) and CV results show high specific capacitance of 186.2 to 298.4 F g −1 and the charge/discharge stability of the prepared materials and the ideal pseudocapacitive behaviors were observed. These results give an opening and promising application of these materials in advanced energy storage applications.