Redox deposition of manganese oxide on graphite for supercapacitors

Wu, Mengqiang; Snook, Graeme A.; Fray, Derek J.

doi:10.1016/j.elecom.2004.03.011

Cited by 199 publications

(160 citation statements)

References 31 publications

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“…59 During the charging/discharging process, the cations including Na + and H + participate in the redox reaction. 18,60 In addition, the Warburg impedance is associated with the semi-infinite diffusion of cations in the electrode, and the capacitive line is related to the accumulation of cations at the impermeable interface under the finite diffusion condition.…”

Section: Resultsmentioning

confidence: 99%

A Synthesis Method of MnO₂/Activated Carbon Composite for Electrochemical Supercapacitors

Wang

Chen

2015

J. Electrochem. Soc.

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In this paper, a MnO 2 /activated carbon (AC) composite with high electrochemical performance is synthesized through a novel synthesis method (Grafting Oxidation Method). The structure and morphology are analyzed using X-ray diffraction, Fourier transmission infrared spectra, scanning electron microscopy and transmission electron microscopy. Additionally, the electrochemical properties are evaluated through cyclic voltammetry, electrochemical impedance spectra and galvanostatic cycling measurements. The results demonstrate this MnO 2 /AC composite owes homogeneous particle size of nanometer dimension. The quasi-rectangular and symmetric cyclic voltammetry curves of the composite, which are measured under a three-electrode electrochemical system with a 0.5 mol L −1 Na 2 SO 4 solution at room temperature, indicate it has an ability of rapidly reversible Faraday reaction and good electrochemical behavior. Compared to the MnO 2 /AC prepared through liquid-phase method, the composite prepared by grafting oxidation method exhibits a much higher specific capacitance which is up to 332.6 F g −1 at scanning rate of 2 mV s −1 . A laboratory capacitor assembled with this MnO 2 /AC composite electrode shows an average capacitance attenuation rate of just 0.0068% after 2000 cycles. Besides, the impedance tests results show that the charge transfer resistance of this composite is 0.92 , which is much lower than the composite (2.52 ) synthesized through liquid-phase method. Supercapacitors, also known as electrochemical capacitors or ultracapacitors, have attracted considerable interest worldwide, primarily because of their ability to provide higher power densities than batteries and higher energy densities than conventional dielectric capacitors. 1,2Because of these advantages, supercapacitors can be widely used in applications such as hybrid vehicles, electronic devices, and digital products. 3-6The most crucial factors determining the electrochemical performance rely on the electrode materials. The electrode-active materials that are widely used for supercapacitors include carbon, conducting polymers and transition-metal oxides. Considering the investigated electrode materials, transition metal oxides are considered to be good alternatives due to their high capacity from pseudocapacitance. 26 have investigated the charge storage mechanism of manganese dioxide compounds with various structures. They discovered that the capacitance of all amorphous compounds was due to faradaic processes localized at the surface and subsurface regions of the electrode. The capacitance of the crystallized materials is clearly dependent upon the crystalline structure, especially with the size of the tunnels that could be able to provide limited cations intercalation. It's also found that the interlayer spacing of the MnO 2 birnessite structure increased upon electrochemical oxidation in the presence of Na + cations in the electrolyte due to the deintercalation of Na + and the intercalation of H 2 O between the layers. 25However, a major drawba...

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Section: Resultsmentioning

confidence: 99%

A Synthesis Method of MnO₂/Activated Carbon Composite for Electrochemical Supercapacitors

Wang

Chen

2015

J. Electrochem. Soc.

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“…[11] A thin film electrode was utilized with glassy carbon as the current collector due to the poor electronic conductivity of MnO2. MnO2 prepared by electrodeposition [18][19][20][21][22] and sol-gel methods [10,[23][24][25] have been reported to show specific capacitance ranging from ~130 F g -1 for powders [25,26] and ~400 F g -1 for thick films [20,22] to ~700 F g -1 for thin films [23,27] in near-neutral aqueous electrolytes. Electrodes prepared by electro-deposition generally lead to higher capacitance than sol-gel derived particles.…”

Section: Introductionmentioning

confidence: 99%

“…according to literature [20] and used as the positive electrode. A mixture of 1.0 M MnSO4·5H2O and 1.0 M H2SO4 in a 1 : 1 volume ratio was used as the electrolytic bath.…”

Section: Preparation Of Electrodesmentioning

confidence: 99%

“…In this work, to demonstrate a more practical cell configuration, thick MnO2 positive electrodes are synthesized on carbon paper by anodic electro-deposition. Since MnO2 can be synthesized directly on conductive carbon, [20] conductive additives are unnecessary. Consequently, uniformity and electronic conductivity of MnO2 electrodes are expected to be improved.…”

Section: Introductionmentioning

confidence: 99%

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Development of a 4.2 V aqueous hybrid electrochemical capacitor based on MnO2 positive and protected Li negative electrodes

Shimizu

Makino

Takahashi

et al. 2013

Journal of Power Sources

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“…Approaches to increase the low specific capacitance of MnO 2 -based electrode include the addition of a conductive additive such as carbons [5][6][7][8][9] or conductive polymers [10][11][12][13][14] to MnO 2 for the fabrication of a composite electrode. On the other hand, the deposition of a thin MnO 2 layer on carbon with various (nano)architectures 7,[15][16][17][18][19][20][21][22][23][24] yielded high capacitance (∼700 F/g) when only the mass of MnO 2 was taking into account. 1,8,9,16 Such composite electrodes show typical specific capacitance in the range of 150-250 F/g.…”

mentioning

confidence: 99%

Chemical Mapping and Electrochemical Performance of Manganese Dioxide/Activated Carbon Based Composite Electrode for Asymmetric Electrochemical Capacitor

Gambou-Bosca

Bélanger

2015

J. Electrochem. Soc.

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A MnO 2 @BP nanocomposite was synthesized by simultaneously reduction of KMnO 4 with Mn(CH 3 COO) 2 .4H 2 O and highly porous Black Pearls 2000 at room temperature. The specific surface area, porosity, crystalline form and conductivity of MnO 2 @BP nanocomposite were characterized by nitrogen gas adsorption measurements, scanning electron microscopy, X-ray diffraction and 4-point probe measurements, respectively. The content of MnO 2 and BP in the composite was determined by thermogravimetric analysis. Chemical mapping using Raman spectroscopy was performed to investigate the distribution of MnO 2 and BP in a composite electrode film prepared with polytetrafluoroethylene (PTFE) as binder. This composite electrode exhibits more homogeneously distributed MnO 2 particles when compared to an electrode made by physical mixing of MnO 2 , BP and PTFE (MnO 2 /BP-PTFE). Also, Raman spectroscopy data of both composite electrodes indicates a loss of electrical conductivity of BP in the case of MnO 2 @BP-PTFE. The electrochemical properties were characterized by cyclic voltammetry in aqueous 0.65 M K 2 SO 4 . The specific capacitance of MnO 2 @BP-PTFE composite electrode was 122 ± 5 F/g, which is statistically equivalent to the capacitance of MnO 2 /BP-PTFE composite electrode (129 ± 6 F/g Owing to its large theoretical capacitance, low cost, environmental friendliness and high density, manganese dioxide (MnO 2 ) is an ideal candidate for positive electrode in asymmetric electrochemical capacitor.1-4 However the performance of MnO 2 -based electrodes is limited by the low electrical and ionic conductivities of MnO 2 . Approaches to increase the low specific capacitance of MnO 2 -based electrode include the addition of a conductive additive such as carbons [5][6][7][8][9] or conductive polymers 10-14 to MnO 2 for the fabrication of a composite electrode. On the other hand, the deposition of a thin MnO 2 layer on carbon with various (nano)architectures 7,15-24 yielded high capacitance (∼700 F/g) when only the mass of MnO 2 was taking into account. 1,8,9,16 Such composite electrodes show typical specific capacitance in the range of 150-250 F/g. Thus, the reported specific capacitance per mass of manganese dioxide is more dependent on the quantity of MnO 2 than the nature of the conductive carbon. 5,8,9,16,[21][22][23][25][26][27][28][29][30][31][32][33] Obtaining good electrochemical performance for MnO 2 -based composite electrodes requires that the electrical contact between MnO 2 and the carbon to be as intimate as possible. 21,34 An attractive approach to achieve it, involves the deposition of MnO 2 onto carbon. 15,22,31,[34][35][36][37][38] By this mean, the effective interfacial area between manganese oxide and the solution is greatly increased. Moreover the contact between MnO 2 and carbon will lead to a high electronic conductivity. MnO 2 has been deposited onto a carbon support by various methods such as sol-gel route, thermal decomposition, electrodeposition, sonochemical synthesis, and redox reaction. 18,31,[34][35]...

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Redox deposition of manganese oxide on graphite for supercapacitors

Cited by 199 publications

References 31 publications

A Synthesis Method of MnO₂/Activated Carbon Composite for Electrochemical Supercapacitors

A Synthesis Method of MnO₂/Activated Carbon Composite for Electrochemical Supercapacitors

Development of a 4.2 V aqueous hybrid electrochemical capacitor based on MnO2 positive and protected Li negative electrodes

Chemical Mapping and Electrochemical Performance of Manganese Dioxide/Activated Carbon Based Composite Electrode for Asymmetric Electrochemical Capacitor

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Redox deposition of manganese oxide on graphite for supercapacitors

Cited by 199 publications

References 31 publications

A Synthesis Method of MnO2/Activated Carbon Composite for Electrochemical Supercapacitors

A Synthesis Method of MnO2/Activated Carbon Composite for Electrochemical Supercapacitors

Development of a 4.2 V aqueous hybrid electrochemical capacitor based on MnO2 positive and protected Li negative electrodes

Chemical Mapping and Electrochemical Performance of Manganese Dioxide/Activated Carbon Based Composite Electrode for Asymmetric Electrochemical Capacitor

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A Synthesis Method of MnO₂/Activated Carbon Composite for Electrochemical Supercapacitors

A Synthesis Method of MnO₂/Activated Carbon Composite for Electrochemical Supercapacitors