Control of manganese dioxide crystallographic structure in the redox reaction between graphene and permanganate ions and their electrochemical performance

Ji, Chenchen; Ren, Haoqi; Yang, Shengchun

doi:10.1039/c5ra01455g

Cited by 34 publications

(16 citation statements)

References 38 publications

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“…The cyclic voltammogram, having two peaks during discharge and having a peak with shoulder during charge, exhibits typical characteristics of the electrochemical insertion/extraction of Zn 2+ ions in MnO 2 structure 12,13,39–41 . These results with two peaks during discharge may be more clearly described by the two-step reaction of Zn 2+ ion insertion in electrochemical reaction 12,38 and spinel-type ZnMn 2 O 4 transformation 33 . In the following scan cycles, the peaks at 1.37 V for δ-MnO 2 and at 1.38 for MNG increase gradually during discharge indicating an activation process 38 .…”

Section: Resultsmentioning

confidence: 71%

“…4(a), a dominating pair of redox peaks exhibits increasing currents when the sweep rates increase, which do not display rectangular-shape and symmetrical voltammograms even at high scan rates, compared to MnO 2 /activated carbon composite for supercapacitors 32 . It is noted that the MNG electrode does not present the capacitive behavior of the electrode 33,34 . The capacitive effect is characterized by analyzing the cyclic voltammetry data at different sweep rates as in Eq.…”

Section: Resultsmentioning

confidence: 99%

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δ-MnO2 nanoflower/graphite cathode for rechargeable aqueous zinc ion batteries

Khamsanga

Pornprasertsuk

Yonezawa

et al. 2019

Sci Rep

170

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Manganese oxide (MnO 2 ) is one of the most promising intercalation cathode materials for zinc ion batteries (ZIBs). Specifically, a layered type delta manganese dioxide (δ-MnO 2 ) allows reversible insertion/extraction of Zn 2+ ions and exhibits high storage capacity of Zn 2+ ions. However, a poor conductivity of δ-MnO 2 , as well as other crystallographic forms, limits its potential applications. This study focuses on δ-MnO 2 with nanoflower structure supported on graphite flake, namely MNG, for use as an intercalation host material of rechargeable aqueous ZIBs. Pristine δ-MnO 2 nanoflowers and MNG were synthesized and examined using X-ray diffraction, electron spectroscopy, and electrochemical techniques. Also, performances of the batteries with the pristine δ-MnO 2 nanoflowers and MNG cathodes were studied in CR2032 coin cells. MNG exhibits a fast insertion/extraction of Zn 2+ ions with diffusion scheme and pseudocapacitive behavior. The battery using MNG cathode exhibited a high initial discharge capacity of 235 mAh/g at 200 mA/g specific current density compared to 130 mAh/g which is displayed by the pristine δ-MnO 2 cathode at the same specific current density. MNG demonstrated superior electrical conductivity compared to the pristine δ-MnO 2 . The results obtained pave the way for improving the electrical conductivity of MnO 2 by using graphite flake support. The graphite flake support significantly improved performances of ZIBs and made them attractive for use in a wide variety of energy applications.

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Section: Resultsmentioning

confidence: 71%

Section: Resultsmentioning

confidence: 99%

δ-MnO2 nanoflower/graphite cathode for rechargeable aqueous zinc ion batteries

Khamsanga

Pornprasertsuk

Yonezawa

et al. 2019

Sci Rep

170

View full text Add to dashboard Cite

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“…While XPS is usually a powerful tool to investigate the chemical composition of amorphous thin films, the interpretation of XPS data is difficult in the case of MnO x due to the sheer number of structures, morphologies, and shapes that exist for each corresponding oxidation state [48–50] . To understand the efficiency towards water splitting, it is especially important for mixed manganese oxides to probe the exact chemical composition because the mix can contain up to three different manganese valences in various concentrations [35,51] .…”

Section: Resultsmentioning

confidence: 99%

Manganese Oxide as an Inorganic Catalyst for the Oxygen Evolution Reaction Studied by X‐Ray Photoelectron and Operando Raman Spectroscopy

et al. 2020

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Manganese oxide (MnOx) is considered a promising material for the oxygen evolution reaction (OER) to replace noble metal catalysts in water splitting. The improvement of MnOx requires mechanistic and kinetic knowledge of the four‐electron transfer steps of the OER. X‐ray photoelectron spectroscopy, a widely used tool to characterize the electronic structure of thin films, is used in combination with surface‐enhanced Raman spectroscopy to gain a deeper knowledge of the different mixed MnOx types and their respective change in chemical composition. Using Raman spectroscopy during electrochemical measurements, all samples were found to reveal Birnessite‐type MnO2 motifs in alkaline media at an applied potential. Their activity correlates with two shifting Raman active modes, one of them being assigned to the formation of MnIII species, and one to the expansion of layers of MnO6 octahedra. A special activation treatment leads independent of the starting material to a highly amorphous mixed‐valence oxide, which shows the highest OER activity.

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“…The results show that a weak diffraction peak can be mainly attributed to the prepared sample, which indicates low crystallinity. Nevertheless, it can still be clearly found that the diffraction peaks at 2θ values of 37.2° and 66.8° were due to the (111) and (020) crystal planes of the birnessite-type MnO 2 (JCPDS 18-0802, Joint Committee on Powder Diffraction Standards (JCPDs), Newtown Square, PA, USA) [ 27 ] and that the peak width of the peak intensity was not strong. It is revealed that the MnO 2 material prepared by the SILAR method was not highly crystalline and that the crystallinity was not perfect.…”

Section: Resultsmentioning

confidence: 99%

Enhanced Activity of Hierarchical Nanostructural Birnessite-MnO2-Based Materials Deposited onto Nickel Foam for Efficient Supercapacitor Electrodes

et al. 2020

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Hierarchical porous birnessite-MnO2-based nanostructure composite materials were prepared on a nickel foam substrate by a successive ionic layer adsorption and reaction method (SILAR). Following composition with reduced graphene oxide (rGO) and multiwall carbon nanotubes (MWCNTs), the as-obtained MnO2, MnO2/rGO and MnO2/rGO-MWCNT materials exhibited pore size distributions of 2–8 nm, 5–15 nm and 2–75 nm, respectively. For the MnO2/rGO-MWCNT material in particular, the addition of MWCNT and rGO enhanced the superb distribution of micropores, mesopores and macropores and greatly improved the electrochemical performance. The as-obtained MnO2/rGO-MWCNT/NF electrode showed a specific capacitance that reached as high as 416 F·g−1 at 1 A·g−1 in 1 M Na2SO4 aqueous electrolyte and also an excellent rate capability and high cycling stability, with a capacitance retention of 85.6% after 10,000 cycles. Electrochemical impedance spectroscopy (EIS) analyses showed a low resistance charge transfer resistance for the as-prepared MnO2/rGO-MWCNT/NF nanostructures. Therefore, MnO2/rGO-MWCNT/NF composites were successfully synthesized and displayed enhanced electrochemical performance as potential electrode materials for supercapacitors.

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Control of manganese dioxide crystallographic structure in the redox reaction between graphene and permanganate ions and their electrochemical performance

Abstract: MnO2 crystallographic structure was well controlled in the redox reaction between graphene and permanganate ions.

Cited by 34 publications

References 38 publications

δ-MnO2 nanoflower/graphite cathode for rechargeable aqueous zinc ion batteries

δ-MnO2 nanoflower/graphite cathode for rechargeable aqueous zinc ion batteries

Manganese Oxide as an Inorganic Catalyst for the Oxygen Evolution Reaction Studied by X‐Ray Photoelectron and Operando Raman Spectroscopy

Enhanced Activity of Hierarchical Nanostructural Birnessite-MnO2-Based Materials Deposited onto Nickel Foam for Efficient Supercapacitor Electrodes

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