The Experts below are selected from a list of 160953 Experts worldwide ranked by ideXlab platform
Qiang Zhang - One of the best experts on this subject based on the ideXlab platform.
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Ion–Solvent Complexes Promote Gas Evolution from Electrolytes on a Sodium Metal Anode
Angewandte Chemie International Edition, 2018Co-Authors: Xiang Chen, Xin Shen, Hong-jie Peng, Xin-bing Cheng, Xue‐qiang Zhang, Jia-qi Huang, Qiang ZhangAbstract:Lithium and sodium metal batteries are considered as promising next-generation energy storage devices due to their ultrahigh energy densities. The high reactivity of alkali metal toward organic solvents and salts results in side reactions, which further lead to undesirable electrolyte depletion, cell failure, and Evolution of flammable Gas. Herein, first-principles calculations and in situ optical microscopy are used to study the mechanism of organic electrolyte decomposition and Gas Evolution on a sodium metal anode. Once complexed with sodium ions, solvent molecules show a reduced LUMO, which facilitates the electrolyte decomposition and Gas Evolution. Such a general mechanism is also applicable to lithium and other metal anodes. We uncover the critical role of ion-solvent complexation for the stability of alkali metal anodes, reveal the mechanism of electrolyte Gassing, and provide a mechanistic guidance to electrolyte and lithium/sodium anode design for safe rechargeable batteries.
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ion solvent complexes promote Gas Evolution from electrolytes on a sodium metal anode
Angewandte Chemie, 2018Co-Authors: Xiang Chen, Xin Shen, Hong-jie Peng, Xin-bing Cheng, Jia-qi Huang, Qiang Zhang, Xueqiang ZhangAbstract:Lithium and sodium metal batteries are considered as promising next-generation energy storage devices due to their ultrahigh energy densities. The high reactivity of alkali metal toward organic solvents and salts results in side reactions, which further lead to undesirable electrolyte depletion, cell failure, and Evolution of flammable Gas. Herein, first-principles calculations and in situ optical microscopy are used to study the mechanism of organic electrolyte decomposition and Gas Evolution on a sodium metal anode. Once complexed with sodium ions, solvent molecules show a reduced LUMO, which facilitates the electrolyte decomposition and Gas Evolution. Such a general mechanism is also applicable to lithium and other metal anodes. We uncover the critical role of ion-solvent complexation for the stability of alkali metal anodes, reveal the mechanism of electrolyte Gassing, and provide a mechanistic guidance to electrolyte and lithium/sodium anode design for safe rechargeable batteries.
Petr Novák - One of the best experts on this subject based on the ideXlab platform.
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CO2 Gas Evolution on Cathode Materials for Lithium-Ion Batteries
Journal of The Electrochemical Society, 2007Co-Authors: Andreas Wuersig, Werner Scheifele, Petr NovákAbstract:The Gas Evolution related to the film formation on cathode materials for lithium-ion batteries was studied using differential electrochemical mass spectrometry and subtractively normalized interfacial Fourier transform infrared spectroscopy. With both methods the oxidative formation of CO 2 was observed in standard battery electrolytes. We show the strong influence of the type of the electrolyte and especially of the additive, vinylene carbonate (VC), as well as the effect of the temperature on the CO 2 Gas formation rate. The VC additive significantly reduces the Gas formation rate in the commonly used voltage window between 3.0 and 4.3 V. Long cycling experiments show that test cells containing VC have a higher cycling stability compared to cells cycled without this additive. Cycling at elevated temperatures (60°C) results in a high, enduring CO 2 Gas Evolution, already starting at a lower cell voltage of about 3.5 V.
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Gas Evolution in activated carbon propylene carbonate based double layer capacitors
Electrochemistry Communications, 2005Co-Authors: M. Hahn, Petr Novák, Andreas Würsig, R. Gallay, Rüdiger KötzAbstract:For the first time Gas Evolution in a double-layer capacitor cell employing activated carbon electrodes and a solution of 1 M (C2H5)4NBF4 in propylene carbonate (PC) has been monitored by means of on-line mass spectrometry (DEMS). During slow scan voltammetry, CO2, propene, and H2 were detected as the major Gaseous decomposition products. Probably propene and H2 are formed by solvent reduction at the negative electrode, while CO2 is formed by solvent oxidation at the positive electrode. A small amount of propene is already detected at a cell voltage of below 1 V. For all species the onset of significant Gas Evolution coincides roughly with the rise of faradaic currents. The increase of coulombic efficiency during subsequent cycling is attributed to passivation processes taking place at both electrodes.
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Gas Evolution in activated carbon propylene carbonate based double layer capacitors
Electrochemistry Communications, 2005Co-Authors: M. Hahn, Petr Novák, Andreas Würsig, R. Gallay, Rüdiger KötzAbstract:For the first time Gas Evolution in a double-layer capacitor cell employing activated carbon electrodes and a solution of 1 M (C2H5)4NBF4 in propylene carbonate (PC) has been monitored by means of on-line mass spectrometry (DEMS). During slow scan voltammetry, CO2, propene, and H2 were detected as the major Gaseous decomposition products. Probably propene and H2 are formed by solvent reduction at the negative electrode, while CO2 is formed by solvent oxidation at the positive electrode. A small amount of propene is already detected at a cell voltage of below 1 V. For all species the onset of significant Gas Evolution coincides roughly with the rise of faradaic currents. The increase of coulombic efficiency during subsequent cycling is attributed to passivation processes taking place at both electrodes. 2005 Elsevier B.V. All rights reserved.
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Gas Evolution in activated carbon/propylene carbonate based double-layer capacitors
Electrochemistry Communications, 2005Co-Authors: M. Hahn, Petr Novák, Andreas Würsig, R. Gallay, Rüdiger KötzAbstract:For the first time Gas Evolution in a double-layer capacitor cell employing activated carbon electrodes and a solution of 1 M (C2H5)4NBF4 in propylene carbonate (PC) has been monitored by means of on-line mass spectrometry (DEMS). During slow scan voltammetry, CO2, propene, and H2 were detected as the major Gaseous decomposition products. Probably propene and H2 are formed by solvent reduction at the negative electrode, while CO2 is formed by solvent oxidation at the positive electrode. A small amount of propene is already detected at a cell voltage of below 1 V. For all species the onset of significant Gas Evolution coincides roughly with the rise of faradaic currents. The increase of coulombic efficiency during subsequent cycling is attributed to passivation processes taking place at both electrodes.
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In situ neutron radiography of lithium-ion batteries: the Gas Evolution on graphite electrodes during the charging
Journal of Power Sources, 2004Co-Authors: Dietrich Goers, Michael Holzapfel, Werner Scheifele, Eberhard Lehmann, Peter Vontobel, Petr NovákAbstract:Abstract In situ neutron radiography (NR) was used to study the Gas Evolution on graphite electrodes in lithium-ion cells containing different PVDF-based gel-type electrolytes. The amount of Gas bubbles and channels was calculated by image analysis. Gas production was extremely high in the case of the electrolyte containing ethylene carbonate (EC) and propylene carbonate (PC) (2:3, w/w), 1 M LiClO 4 . About 60% of the electrode surface consisted of the Gas phase which resulted in an inhomogeneous local current distribution. In contrast, the electrolyte containing EC and γ-butyrolactone (GBL) (1:1, w/w), 1 M LiBF 4 only showed a small increase of the Gas volume between the electrodes of about 3%. In situ NR also revealed the displacement of the electrolyte due to Gas Evolution and volume changes of the electrodes.
Xiang Chen - One of the best experts on this subject based on the ideXlab platform.
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Ion–Solvent Complexes Promote Gas Evolution from Electrolytes on a Sodium Metal Anode
Angewandte Chemie International Edition, 2018Co-Authors: Xiang Chen, Xin Shen, Hong-jie Peng, Xin-bing Cheng, Xue‐qiang Zhang, Jia-qi Huang, Qiang ZhangAbstract:Lithium and sodium metal batteries are considered as promising next-generation energy storage devices due to their ultrahigh energy densities. The high reactivity of alkali metal toward organic solvents and salts results in side reactions, which further lead to undesirable electrolyte depletion, cell failure, and Evolution of flammable Gas. Herein, first-principles calculations and in situ optical microscopy are used to study the mechanism of organic electrolyte decomposition and Gas Evolution on a sodium metal anode. Once complexed with sodium ions, solvent molecules show a reduced LUMO, which facilitates the electrolyte decomposition and Gas Evolution. Such a general mechanism is also applicable to lithium and other metal anodes. We uncover the critical role of ion-solvent complexation for the stability of alkali metal anodes, reveal the mechanism of electrolyte Gassing, and provide a mechanistic guidance to electrolyte and lithium/sodium anode design for safe rechargeable batteries.
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ion solvent complexes promote Gas Evolution from electrolytes on a sodium metal anode
Angewandte Chemie, 2018Co-Authors: Xiang Chen, Xin Shen, Hong-jie Peng, Xin-bing Cheng, Jia-qi Huang, Qiang Zhang, Xueqiang ZhangAbstract:Lithium and sodium metal batteries are considered as promising next-generation energy storage devices due to their ultrahigh energy densities. The high reactivity of alkali metal toward organic solvents and salts results in side reactions, which further lead to undesirable electrolyte depletion, cell failure, and Evolution of flammable Gas. Herein, first-principles calculations and in situ optical microscopy are used to study the mechanism of organic electrolyte decomposition and Gas Evolution on a sodium metal anode. Once complexed with sodium ions, solvent molecules show a reduced LUMO, which facilitates the electrolyte decomposition and Gas Evolution. Such a general mechanism is also applicable to lithium and other metal anodes. We uncover the critical role of ion-solvent complexation for the stability of alkali metal anodes, reveal the mechanism of electrolyte Gassing, and provide a mechanistic guidance to electrolyte and lithium/sodium anode design for safe rechargeable batteries.
Rüdiger Kötz - One of the best experts on this subject based on the ideXlab platform.
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Gas Evolution in activated carbon propylene carbonate based double layer capacitors
Electrochemistry Communications, 2005Co-Authors: M. Hahn, Petr Novák, Andreas Würsig, R. Gallay, Rüdiger KötzAbstract:For the first time Gas Evolution in a double-layer capacitor cell employing activated carbon electrodes and a solution of 1 M (C2H5)4NBF4 in propylene carbonate (PC) has been monitored by means of on-line mass spectrometry (DEMS). During slow scan voltammetry, CO2, propene, and H2 were detected as the major Gaseous decomposition products. Probably propene and H2 are formed by solvent reduction at the negative electrode, while CO2 is formed by solvent oxidation at the positive electrode. A small amount of propene is already detected at a cell voltage of below 1 V. For all species the onset of significant Gas Evolution coincides roughly with the rise of faradaic currents. The increase of coulombic efficiency during subsequent cycling is attributed to passivation processes taking place at both electrodes. 2005 Elsevier B.V. All rights reserved.
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Gas Evolution in activated carbon propylene carbonate based double layer capacitors
Electrochemistry Communications, 2005Co-Authors: M. Hahn, Petr Novák, Andreas Würsig, R. Gallay, Rüdiger KötzAbstract:For the first time Gas Evolution in a double-layer capacitor cell employing activated carbon electrodes and a solution of 1 M (C2H5)4NBF4 in propylene carbonate (PC) has been monitored by means of on-line mass spectrometry (DEMS). During slow scan voltammetry, CO2, propene, and H2 were detected as the major Gaseous decomposition products. Probably propene and H2 are formed by solvent reduction at the negative electrode, while CO2 is formed by solvent oxidation at the positive electrode. A small amount of propene is already detected at a cell voltage of below 1 V. For all species the onset of significant Gas Evolution coincides roughly with the rise of faradaic currents. The increase of coulombic efficiency during subsequent cycling is attributed to passivation processes taking place at both electrodes.
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Gas Evolution in activated carbon/propylene carbonate based double-layer capacitors
Electrochemistry Communications, 2005Co-Authors: M. Hahn, Petr Novák, Andreas Würsig, R. Gallay, Rüdiger KötzAbstract:For the first time Gas Evolution in a double-layer capacitor cell employing activated carbon electrodes and a solution of 1 M (C2H5)4NBF4 in propylene carbonate (PC) has been monitored by means of on-line mass spectrometry (DEMS). During slow scan voltammetry, CO2, propene, and H2 were detected as the major Gaseous decomposition products. Probably propene and H2 are formed by solvent reduction at the negative electrode, while CO2 is formed by solvent oxidation at the positive electrode. A small amount of propene is already detected at a cell voltage of below 1 V. For all species the onset of significant Gas Evolution coincides roughly with the rise of faradaic currents. The increase of coulombic efficiency during subsequent cycling is attributed to passivation processes taking place at both electrodes.
Hong-jie Peng - One of the best experts on this subject based on the ideXlab platform.
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Ion–Solvent Complexes Promote Gas Evolution from Electrolytes on a Sodium Metal Anode
Angewandte Chemie International Edition, 2018Co-Authors: Xiang Chen, Xin Shen, Hong-jie Peng, Xin-bing Cheng, Xue‐qiang Zhang, Jia-qi Huang, Qiang ZhangAbstract:Lithium and sodium metal batteries are considered as promising next-generation energy storage devices due to their ultrahigh energy densities. The high reactivity of alkali metal toward organic solvents and salts results in side reactions, which further lead to undesirable electrolyte depletion, cell failure, and Evolution of flammable Gas. Herein, first-principles calculations and in situ optical microscopy are used to study the mechanism of organic electrolyte decomposition and Gas Evolution on a sodium metal anode. Once complexed with sodium ions, solvent molecules show a reduced LUMO, which facilitates the electrolyte decomposition and Gas Evolution. Such a general mechanism is also applicable to lithium and other metal anodes. We uncover the critical role of ion-solvent complexation for the stability of alkali metal anodes, reveal the mechanism of electrolyte Gassing, and provide a mechanistic guidance to electrolyte and lithium/sodium anode design for safe rechargeable batteries.
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ion solvent complexes promote Gas Evolution from electrolytes on a sodium metal anode
Angewandte Chemie, 2018Co-Authors: Xiang Chen, Xin Shen, Hong-jie Peng, Xin-bing Cheng, Jia-qi Huang, Qiang Zhang, Xueqiang ZhangAbstract:Lithium and sodium metal batteries are considered as promising next-generation energy storage devices due to their ultrahigh energy densities. The high reactivity of alkali metal toward organic solvents and salts results in side reactions, which further lead to undesirable electrolyte depletion, cell failure, and Evolution of flammable Gas. Herein, first-principles calculations and in situ optical microscopy are used to study the mechanism of organic electrolyte decomposition and Gas Evolution on a sodium metal anode. Once complexed with sodium ions, solvent molecules show a reduced LUMO, which facilitates the electrolyte decomposition and Gas Evolution. Such a general mechanism is also applicable to lithium and other metal anodes. We uncover the critical role of ion-solvent complexation for the stability of alkali metal anodes, reveal the mechanism of electrolyte Gassing, and provide a mechanistic guidance to electrolyte and lithium/sodium anode design for safe rechargeable batteries.
