High-temperature electrochemical synthesis of carbon-containing inorganic compounds under excessive carbon dioxide pressure

Новоселова, И. А.; Волков, С. В.; Oliinyk, N.F.; Shapoval, V. I.

doi:10.2298/jmmb0302281n

Cited by 22 publications

(15 citation statements)

References 7 publications

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“…E * is the equilibrium potential linked to the formal standard potential, 47 E • of the reaction, ln (c * Ni(II) ) = n f (E * − E • ) [17] c * Ni(II) is the concentration of metal ions at equilibrium (mol l −1 ). The concentration change of the Ni(II) species in the vicinity of the electrode surface was calculated by integration of the diffusion equation using the finite difference technique.…”

Section: Carbon-metal Production Testing In Carbonates Meltsmentioning

confidence: 99%

Electrodeposition of Carbon-Metal Powders in Alkali Carbonate Melts

Groult

Ван

Lantelme

2014

J. Electrochem. Soc.

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In the frame of the preparation of carbonaceous materials that could serve for instance as anodic components in lithium batteries, an original way has been proposed based on the electroreduction of carbonate ions in ternary molten Li-Na-K carbonates. The TEM and XRD analyses show that the powders produced at the cathode are made of carbon nanoparticles composed of both amorphous and graphitized domains. The characteristic properties of the product depend on the operating conditions: voltage, melt temperature and annealing temperature. BET investigations show that the active surface area of the powders obtained at high voltage (6 V) and low melt temperature (450 • C) grows to a value of up to 1300 m 2 g −1 . An improvement of the anodic material in lithium batteries can be obtained by introducing in the carbon powder suitable metals such as tin. The production of such mixtures can be realized directly, in one single operation, by electroreduction of metal ions dissolved in the alkali carbonate melt. The mechanism of metal deposition is briefly studied by cyclic voltammetry. Composite powders are electrodeposited at constant potential. TEM and EDX investigations show that they are made of an intimate mixture of carbon and metal grains at the nanometric scale, the metallic grains size ranging from 5 to 20 nm.In the field of rechargeable lithium batteries much effort has been devoted to the development of efficient negative electrodes. 1,2 Indeed, from a theoretical point of view, the best device would be to use lithium metal as an anode material; however, lithium is highly active and reacts with most electrolytes. Further, the morphology of lithium deposits is dendritic, inducing a non-dimensionally stable electrode. In modern cells these disadvantages were alleviated by using lithium alloys or by inserting lithium atoms in a host material. Of course, it results in a decrease of specific energy and the inconvenience can be accepted if the use of such anode materials significantly improves cycle life and safety. The additional compounds are generally made of carbon or metals such as tin or silicon.The performances of carbon materials strongly depend on the carbon structure which varies from the highly crystalline graphite to strongly disordered carbon. [3][4][5][6][7][8][9] The layered structure of graphite is particularly well adapted to the insertion of lithium which occurs between the graphite sheets. Some advantage has also been found by using hard carbon which develops high capacity at low potential and inserts lithium over a large potential range. The gradual potential change is an advantage for practical uses since it permits a more accurate estimate of the remaining capacity. Different techniques were used to produce such carbonaceous materials notably from electrochemical route by electro-oxidation, or from electro-reduction of molten salts. 10-17 In our laboratory, the generation of carbon powders was carried out by electro-reduction of alkali carbonate melts. 18-24 Quasi-spherical carbon nano-particles wer...

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Section: Carbon-metal Production Testing In Carbonates Meltsmentioning

confidence: 99%

Electrodeposition of Carbon-Metal Powders in Alkali Carbonate Melts

Groult

Ван

Lantelme

2014

J. Electrochem. Soc.

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“…The earlier research of Novoselova et al 27 failed to observe the direct conversion of CO2 to C and O2 at high partial pressures of CO2; however, it did note that increased partial pressures of CO2 corresponded to less negative deposition potentials of carbon from an equimolar melt of NaCl and KCl in the range of 750°C to 850°C.…”

Section: 6 E F F E C T O F G a S E O U S A T M O S P H E R Ementioning

confidence: 84%

“…Recent research into the reduction of carbonate-containing materials has begun to examine the electrolytic reduction of molten carbonate containing salts for the formation of carbonaceous products 5,11,13,14,[20][21][22][23][24][25][26][27][28][29][30][31] . Unlike reduction in aqueous media there is no water present during this form of electrolytic reaction, hence the mechanism of carbonate reduction is demonstrated by Eqn (1); i.e., CO3 2-+ 4e - C + 3O 2-… (1) which shows the redox couple for the electrolytic reduction of molten carbonate salts 5 .…”

Section: E L E C T R O C H E M I C a L D E P O S I T I O N F R O M mentioning

confidence: 99%

Carbonate Reduction and the Properties and Applications of Carbon Formed Through Electrochemical Deposition in Molten Carbonates: A Review

Hughes

Allen

Donne

2015

Electrochimica Acta

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“…This difference is probably due to the fact that, at such a small value for the overpotential, the electrochemical formation of tungsten carbide takes place. [29][30][31] Thus, based on the data listed in Table II, at overpotential values of −2.10, −2.15, and −2.21 V, the diffusion coefficient D for CO3 2− electroreduction in the current melt is calculated to be 4.0×10 −10 cm 2 /s.…”

Section: Accepted M Manuscriptmentioning

confidence: 99%

Electrochemical Mechanism of the Carbon Synthesis via Carbonate Ion Electroreduction in Molten Li2CO3–K2CO3 Mixture

2022

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As a way to explore methods to capture and transform CO2 into useful carbon materials, the electrochemical mechanism of carbonate ion reduction in molten Li2CO3-K2CO3 eutectic mixtures is studied by cyclic voltammetry, chronopotentiometry, and chronocoulometry.Evidence indicates CO3 2− to undergo reduction to produce solid carbon before the alkali metal ions Li + and K + . The electrode reactions consist of a diffusion-controlled, totally irreversible process comprising a one-step electron transfer. Notably, the described electrochemical process produces carbon sheets, submicron carbon tubes, or submicron carbon particles, depending on the applied cathodic overpotential. When O 2− ions are released as part of the electrochemical reduction of CO3 2− , some of these ions immediately combine with Li + to form insoluble Li2O, which are disadvantageous processes from the standpoint of CO2 capture in the cathodic region.Results suggest thus that a type of molten salt electrolyte in which alkali metal oxides are highly soluble should be employed for effective molten salt CO2 capture and electrochemical transformation.

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High-temperature electrochemical synthesis of carbon-containing inorganic compounds under excessive carbon dioxide pressure

Cited by 22 publications

References 7 publications

Electrodeposition of Carbon-Metal Powders in Alkali Carbonate Melts

Electrodeposition of Carbon-Metal Powders in Alkali Carbonate Melts

Carbonate Reduction and the Properties and Applications of Carbon Formed Through Electrochemical Deposition in Molten Carbonates: A Review

Electrochemical Mechanism of the Carbon Synthesis via Carbonate Ion Electroreduction in Molten Li<sub>2</sub>CO<sub>3</sub>–K<sub>2</sub>CO<sub>3</sub> Mixture

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