In-situ Raman spectroscopic studies on the oxide species in molten Li/K2CO3

Chen, Lijiang; Cheng, Xuan; Lin, Changjian; Huang, Chenguang

doi:10.1016/s0013-4686(01)00872-6

Cited by 16 publications

(28 citation statements)

References 20 publications

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“…14-17 But both sides of the debate encountered the lack of clear-cut experimental evidence. By means of in-situ Raman spectroscopy, we recently observed in basic molten carbonate the presence of peroxide anion, 18 which was produced by the following reactions:…”

Section: Introductionmentioning

confidence: 99%

First Spectroscopic Observation of Peroxocarbonate/ Peroxodicarbonate in Molten Carbonate

et al. 2004

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An active oxygen species in molten carbonate is the key to elucidate the complex mechanism of the cathode reaction in MCFC. However, under acidic condition of MCFC operation (P CO 2 > 1.01 × 10 4 Pa), the exact chemical state of the active oxygen species remains unclear and is a subject of continuous debates. In this work, we present the first experimental observation of peroxocarbonate/peroxodicarbonate species in acidic molten carbonate by using in-situ Raman spectroscopic technique. The results indicate that the predominant oxygen species (O 2 2-) in basic lithium-rich melts became unstable with the increase of acidity level in the melts and reacted with CO 2 to produce peroxocarbonate or peroxodicarbonate anion. In combination with the result of theoretical calculation, it is deduced that the peroxodicarbonate mechanism is the dominant feature in the cathode reaction path in MCFC.

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Section: Introductionmentioning

confidence: 99%

First Spectroscopic Observation of Peroxocarbonate/ Peroxodicarbonate in Molten Carbonate

et al. 2004

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“…In the second step, after air-drying, the deposited samples were sintered at 923 K in an N 2 atmosphere for 3 h. This paper mainly focuses on the deformation/dissolution behavior of the LiCoO 2 -Ni composite during its transformation to LiCoO 2 -NiO under load. The in-situ deformation-measuring system and the experimental details can be found in a previous paper [15]. Similar to previous tests, the deformation of the 1 cm 2 3 Results and discussion Compared with that of green porous nickel ( Fig.…”

Section: Methodsmentioning

confidence: 53%

“…Therefore, the projections were probably formed by the reprecipitation of dissolving nickel ions and oxide ions in the molten carbonate [15,16]. It can be presumed that an obvious nickel dissolution occurred when the porous nickel deformed severely.…”

Section: Methodsmentioning

confidence: 99%

“…However, there are still difficulties in applying the new materials to practical situations in industry. The early deformation of the cathode material has also been confirmed to be a potential danger to short circuiting and to be another significant factor resulting in short cell life under actual MCFC operating conditions [15,16]. Thus, it is highly desirable to develop a better cathode material with a lower dissolution rate, lighter deformation, and easier application to the actual MCFC industry.…”

Section: Introductionmentioning

confidence: 99%

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A Novel MCFC Cathode Material Modified by the EPD Technique

Chen

Zuo

Lin³

2003

Fuel Cells

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The early deformation of the cathode material has been confirmed to be a significant factor in shortening the cell life. Thus, a new kind of cathode with both lower solubility and lighter deformation is highly desirable. In this work, a novel composite material, LiCoO2‐Ni, was prepared by the electrophoretic deposition (EPD) technique, which, remarkably, is able to reduce the deformation and dissolution of cathode materials simultaneously. It was demonstrated to be very promising for the MCFC industry.

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“…Of particular interest are the various structures of peroxide containing complex anions. The bent structure of KO 2 − is the lowest energy form by 5.8 and 10.5 kcal in energy lower than the linear and triangular structures of 14−16 The calculated Raman frequencies were seen to match the experimental results to within 6%, as shown in Figure 26. 14−16 This approach rules out several anions (including free carbonate) that are not coordinated to an individual monovalent cation in the high temperature carbonate melts.…”

Section: −16mentioning

confidence: 55%