Electrochemical Intercalation of Alkali-Metal Ions into Birnessite-Type Manganese Oxide in Aqueous Solution

Kanoh, Hirofumi; Tang, Weiping; Makita, Yoji; Ooi, Kenta

doi:10.1021/la970767d

Cited by 102 publications

(103 citation statements)

References 27 publications

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“…The approximate 7 Å interlayer distances are indicative of birnessite-type manganese oxides and the increased spacing associated with larger alkali metal cations is consistent with other studies involving synthetic birnessites [30].…”

Section: Characterizationsupporting

confidence: 89%

Manganese oxide thin films prepared by nonaqueous sol–gel processing: preferential formation of birnessite

Ching

Hughes

Gray

et al. 2004

Microporous and Mesoporous Materials

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High quality manganese oxide thin films with smooth surfaces and even thicknesses have been prepared with a nonaqueous sol-gel process involving reduction of tetraethylammonium permanganate in methanol. Spin-coated films have been cast onto soft glass, quartz, and Ni foil substrates, with two coats being applied for optimum crystallization. The addition of alkali metal cations as dopants results in exclusive formation of the layered birnessite phase. By contrast, analogous reactions in bulk solgel reactions yield birnessite, tunneled, and spinel phases depending on the dopant cation.XRD patterns confirm the formation of well-crystallized birnessite. SEM images of Li-, Na-, and K-birnessite reveal extremely smooth films having uniform thickness of less than 0.5 µm. Thin films of Rb-and Cs-birnessite have more fractured and uneven surfaces as a result of some precipitation during the sol-gel transformation. All films consist of densely packed particles of about 0.1 µm. When tetrabutylammonium permanganate is used instead of tetraethylammonium permanganate, the sol-gel reaction yields amorphous manganese oxide as the result of diluted Mn sites in the xerogel film.Bilayer films have been prepared by casting an overcoat of K-birnessite onto a Na-2 birnessite film. However, Auger depth profiling indicates considerable mixing between the adjacent layers.

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Section: Characterizationsupporting

confidence: 89%

Manganese oxide thin films prepared by nonaqueous sol–gel processing: preferential formation of birnessite

Ching

Hughes

Gray

et al. 2004

Microporous and Mesoporous Materials

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“…Thus, the redox pair observed at 0.60 V/0.30 V in powder Kbirnessite in K 2 SO 4 electrolyte has been assigned to the deintercalation/intercalation of K + from/into the K-birnessite lattice accompanied by the Mn 3+ oxidation/Mn 4+ reduction [6]. Kanoh et al [28] have reported a very complex mechanism for deintercalation/intercalation process in K-birnessite in aqueous KCl solution, where not K + , but H + is electrochemically active [28]. In that case the K-deintercalation (accordingly, K-intercalation) occurs by H 2 O intercalation followed by ion exchange between K + and H + [28].…”

Section: Electrochemical Propertiesmentioning

confidence: 99%

“…Kanoh et al [28] have reported a very complex mechanism for deintercalation/intercalation process in K-birnessite in aqueous KCl solution, where not K + , but H + is electrochemically active [28]. In that case the K-deintercalation (accordingly, K-intercalation) occurs by H 2 O intercalation followed by ion exchange between K + and H + [28]. Another electrochemical studies on Kbirnessite in aqueous KCl and tetrabutylammonium chloride (TBACl) electrolytes evidence that both K + and H + play an important role in the electrochemical conversion between Mn 4+ and Mn 3+ [29].…”

Section: Electrochemical Propertiesmentioning

confidence: 99%

A simple chemical method for deposition of electrochromic potassium manganese oxide hydrate thin films

Najdoski

Koleva

Demiri

et al. 2012

Materials Research Bulletin

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“…12,14,15,32,34 More recent EQCM reports examined MnOx pseudocapacitance phenomena and showed that cation insertion and ejection during reduction and oxidation, respectively, is the primary charge-compensation mechanism. 16,32,35 Traditional quartz crystal microbalance (QCM) experiments rely on the assumption that films are acoustically thin, thus allowing for gravimetric interpretation of the results using the Sauerbrey equation.…”

Section: Resultsmentioning

confidence: 99%

Extending Electrochemical Quartz Crystal Microbalance Techniques to Macroscale Electrodes: Insights on Pseudocapacitance Mechanisms in MnOx-Coated Carbon Nanofoams

Beasley¹,

Sassin

Long

2015

J. Electrochem. Soc.

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Electrochemical quartz crystal microbalance studies of MnOx-coated carbon nanofoams reveal that charge-compensation mechanisms associated with MnOx pseudocapacitance in mild aqueous electrolytes are dominated by anion insertion rather than more commonly reported cation ejection. Specific charge-compensation behavior depends on such factors as electrolyte composition, nanofoam pore size, and polarization amplitude. For example, MnOx-carbon nanofoams with average pore sizes of 5-20 nm, cycled in 2.5 M LiNO 3 , reveal a kinetically-hindered, mixed anion-cation charge-compensation mechanism, whereas the same nanofoam cycled in 2.5 M NaNO 3 shows only anion association. Nanofoams with larger pores (10-200 nm) Transition metal oxides that exhibit "pseudocapacitance", capacitor-like behavior that arises from faradaic reactions, are challenging high-surface-area carbons, which rely primarily on doublelayer capacitance, as active materials in next-generation electrochemical capacitors (ECs).1-4 Because pseudocapacitance involves electrontransfer reactions, the quantity of charge-storage per mass or volume often surpasses that achieved with double-layer capacitance alone. The enhanced charge-storage capacity provided by pseudocapacitive metal oxides compensates for the voltage limitations of aqueous-electrolyte ECs, resulting in asymmetric aqueous EC designs 5-7 that provide competitive performance and safer operation compared to conventional symmetric carbon-carbon ECs that use organic electrolytes.Manganese oxides (MnOx) have emerged as one of the most important classes of pseudocapacitive materials due to their low cost, competitive specific capacitance, availability in a wide range of compositions and crystal habits, and adaptability to a variety of electrode architectures. [8][9][10][11] The electrochemical characteristics of MnOx have been extensively demonstrated, yet the underlying mechanisms responsible for pseudocapacitance are still a subject of debate. Spectroscopic methods have been used to confirm that pseudocapacitive charge storage is supported by reversible toggling of the Mn oxidation state (ranging between +3 and +4, but typically <1 e -per Mn site) during electrochemical cycling in aqueous electrolytes. [12][13][14] Changes in Mn oxidation state must be accompanied by insertion or adsorption of charge-balancing ions from the contacting electrolyte. In the case of mild aqueous electrolytes, charge compensation typically occurs via cation-insertion/association mechanisms where the cations are supplied by either the electrolyte salt (e.g., Li + , Na + , or K + ), the H 2 O solvent (in the form of H + or H 3 O + ), or combinations thereof.14-20 Because of the prospective participation of multiple types of ions (in varying degrees of solvation), deconvolution of MnOx pseudocapacitance mechanisms has proven difficult. The ability to draw broader conclusions regarding MnOx pseudocapacitance mechanisms has been further complicated by the wide range of materials that are broadly identified in the literature a...

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Electrochemical Intercalation of Alkali-Metal Ions into Birnessite-Type Manganese Oxide in Aqueous Solution

Cited by 102 publications

References 27 publications

Manganese oxide thin films prepared by nonaqueous sol–gel processing: preferential formation of birnessite

Manganese oxide thin films prepared by nonaqueous sol–gel processing: preferential formation of birnessite

A simple chemical method for deposition of electrochromic potassium manganese oxide hydrate thin films

Extending Electrochemical Quartz Crystal Microbalance Techniques to Macroscale Electrodes: Insights on Pseudocapacitance Mechanisms in MnOx-Coated Carbon Nanofoams

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