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Sascha Nowak - One of the best experts on this subject based on the ideXlab platform.
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qualitative and quantitative investigation of organophosphates in an electrochemically and thermally treated lithium hexaFluorophosphate based lithium ion battery electrolyte by a developed liquid chromatography tandem quadrupole mass spectrometry method
RSC Advances, 2016Co-Authors: Vadim Kraft, Waldemar Weber, Ralf Wagner, Martin Winter, Benjamin Streipert, Carola Schultz, Sascha NowakAbstract:The presented work was focused on the development of a new liquid chromatography-tandem quadrupole mass spectrometry method (LC-MS/MS) for the identification and quantification of organophosphates in lithium hexaFluorophosphate (LiPF6)-based lithium ion battery electrolytes. The investigated electrolyte consists of 1 M LiPF6 dissolved in ethylene carbonate/ethyl methyl carbonate (50/50, wt%) and was treated electrochemically and thermally. For the electrochemical experiments, the cut-off potential in the half cells was held at 5.5 V for 72 h. The thermal degradation experiments were performed in aluminum vials at 95 °C for a period of 13 days. In the first part of this work, an already established gas chromatography-mass spectrometry (GC-MS) method for identification of dimethyl Fluorophosphates (DMFP) and diethyl Fluorophosphate (DEFP) was applied. In the second part, the LC-MS/MS method including determination of characteristic transitions in a product ion scan was developed. The developed method was applied for the identification of various analytes in the decomposed electrolytes. In addition, a possible formation of ionic and non-ionic OPs based on findings of this work and our previous reports is presented. In the third and final part, a quantification study of DMFP and DEFP was performed with a newly developed LC-MS/MS method and compared with results obtained by GC-MS. In addition, trimethyl phosphate (TMP) and triethyl phosphate (TEP) were quantified. These studies included the investigation of the suppression effects caused by the sample matrix during the application of the LC-MS/MS method.
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study of decomposition products by gas chromatography mass spectrometry and ion chromatography electrospray ionization mass spectrometry in thermally decomposed lithium hexaFluorophosphate based lithium ion battery electrolytes
RSC Advances, 2015Co-Authors: Vadim Kraft, Waldemar Weber, Martin Grutzke, Martin Winter, Sascha NowakAbstract:In this work, the thermal decomposition of a lithium ion battery electrolyte (1 M LiPF6 in ethylene carbonate/ethyl methyl carbonate, 50/50 wt%) with a focus on the formation of organophosphates was systematically studied. The quantification of non-ionic dimethyl Fluorophosphate and diethyl Fluorophosphate was performed with synthesized standards by gas chromatography-mass spectrometry. Due to absence of commercially available or synthesized standards for the monitoring of ionic methyl Fluorophosphate, ethyl Fluorophosphate and ethylene phosphate a method working with ion chromatography-electrospray ionization-mass spectrometry was developed, where dibutyl phosphate was used as an internal standard. In addition, an ion chromatography conductivity detection method with short analysis time for simultaneous determination and quantification of F−, PF6− and BF4− was developed. The formation and degradation of analytes was studied to show the dependence of different temperatures, electrolyte volumes and separator materials. The thermal aging experiments were carried out in gas-tight aluminum vials at 80 °C for three weeks. After the storage time, the samples were diluted with the appropriate analysis solvents and investigated with gas chromatography-mass spectrometry, ion chromatography and ion chromatography-electrospray ionization-mass spectrometry. Finally, the thermal degradation of the electrolyte at 85 °C after five days in aluminum and glass vials was studied.
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identification of alkylated phosphates by gas chromatography mass spectrometric investigations with different ionization principles of a thermally aged commercial lithium ion battery electrolyte
Journal of Chromatography A, 2015Co-Authors: Waldemar Weber, Vadim Kraft, Martin Grutzke, Ralf Wagner, Martin Winter, Sascha NowakAbstract:Abstract The thermal aging process of a commercial LiPF6 based lithium ion battery electrolyte has been investigated in view of the formation of volatile phosphorus-containing degradation products. Aging products were analyzed by GC–MS. Structure determination of the products was performed by support of chemical ionization MS in positive and negative modes. A fraction of the discovered compounds belongs to the group of Fluorophosphates (phosphorofluoridates) which are in suspect of potential toxicity. This is well known for relative derivatives, e.g. diisopropyl Fluorophosphate. Another fraction of the identified compounds belongs to the group of trialkyl phosphates. These compounds may provide a positive impact on the thermal and electrochemical performance of Li-based batteries as repeatedly described in the literature.
Vadim Kraft - One of the best experts on this subject based on the ideXlab platform.
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qualitative and quantitative investigation of organophosphates in an electrochemically and thermally treated lithium hexaFluorophosphate based lithium ion battery electrolyte by a developed liquid chromatography tandem quadrupole mass spectrometry method
RSC Advances, 2016Co-Authors: Vadim Kraft, Waldemar Weber, Ralf Wagner, Martin Winter, Benjamin Streipert, Carola Schultz, Sascha NowakAbstract:The presented work was focused on the development of a new liquid chromatography-tandem quadrupole mass spectrometry method (LC-MS/MS) for the identification and quantification of organophosphates in lithium hexaFluorophosphate (LiPF6)-based lithium ion battery electrolytes. The investigated electrolyte consists of 1 M LiPF6 dissolved in ethylene carbonate/ethyl methyl carbonate (50/50, wt%) and was treated electrochemically and thermally. For the electrochemical experiments, the cut-off potential in the half cells was held at 5.5 V for 72 h. The thermal degradation experiments were performed in aluminum vials at 95 °C for a period of 13 days. In the first part of this work, an already established gas chromatography-mass spectrometry (GC-MS) method for identification of dimethyl Fluorophosphates (DMFP) and diethyl Fluorophosphate (DEFP) was applied. In the second part, the LC-MS/MS method including determination of characteristic transitions in a product ion scan was developed. The developed method was applied for the identification of various analytes in the decomposed electrolytes. In addition, a possible formation of ionic and non-ionic OPs based on findings of this work and our previous reports is presented. In the third and final part, a quantification study of DMFP and DEFP was performed with a newly developed LC-MS/MS method and compared with results obtained by GC-MS. In addition, trimethyl phosphate (TMP) and triethyl phosphate (TEP) were quantified. These studies included the investigation of the suppression effects caused by the sample matrix during the application of the LC-MS/MS method.
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study of decomposition products by gas chromatography mass spectrometry and ion chromatography electrospray ionization mass spectrometry in thermally decomposed lithium hexaFluorophosphate based lithium ion battery electrolytes
RSC Advances, 2015Co-Authors: Vadim Kraft, Waldemar Weber, Martin Grutzke, Martin Winter, Sascha NowakAbstract:In this work, the thermal decomposition of a lithium ion battery electrolyte (1 M LiPF6 in ethylene carbonate/ethyl methyl carbonate, 50/50 wt%) with a focus on the formation of organophosphates was systematically studied. The quantification of non-ionic dimethyl Fluorophosphate and diethyl Fluorophosphate was performed with synthesized standards by gas chromatography-mass spectrometry. Due to absence of commercially available or synthesized standards for the monitoring of ionic methyl Fluorophosphate, ethyl Fluorophosphate and ethylene phosphate a method working with ion chromatography-electrospray ionization-mass spectrometry was developed, where dibutyl phosphate was used as an internal standard. In addition, an ion chromatography conductivity detection method with short analysis time for simultaneous determination and quantification of F−, PF6− and BF4− was developed. The formation and degradation of analytes was studied to show the dependence of different temperatures, electrolyte volumes and separator materials. The thermal aging experiments were carried out in gas-tight aluminum vials at 80 °C for three weeks. After the storage time, the samples were diluted with the appropriate analysis solvents and investigated with gas chromatography-mass spectrometry, ion chromatography and ion chromatography-electrospray ionization-mass spectrometry. Finally, the thermal degradation of the electrolyte at 85 °C after five days in aluminum and glass vials was studied.
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identification of alkylated phosphates by gas chromatography mass spectrometric investigations with different ionization principles of a thermally aged commercial lithium ion battery electrolyte
Journal of Chromatography A, 2015Co-Authors: Waldemar Weber, Vadim Kraft, Martin Grutzke, Ralf Wagner, Martin Winter, Sascha NowakAbstract:Abstract The thermal aging process of a commercial LiPF6 based lithium ion battery electrolyte has been investigated in view of the formation of volatile phosphorus-containing degradation products. Aging products were analyzed by GC–MS. Structure determination of the products was performed by support of chemical ionization MS in positive and negative modes. A fraction of the discovered compounds belongs to the group of Fluorophosphates (phosphorofluoridates) which are in suspect of potential toxicity. This is well known for relative derivatives, e.g. diisopropyl Fluorophosphate. Another fraction of the identified compounds belongs to the group of trialkyl phosphates. These compounds may provide a positive impact on the thermal and electrochemical performance of Li-based batteries as repeatedly described in the literature.
Naohiro Soga - One of the best experts on this subject based on the ideXlab platform.
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upconversion properties multiphonon relaxation and local environment of rare earth ions in Fluorophosphate glasses
Physical Review B, 1992Co-Authors: Setsuhisa Tanabe, Shigeo Yoshii, Kazuyuki Hirao, Naohiro SogaAbstract:The upconversion properties of Er{sup 3+} ions were studied for the Fluorophosphate glasses (45{minus}{ital x})AlF{sub 3}{center dot}{ital x}AlPO{sub 4}{center dot}5ErF{sub 3}{center dot}30CaF{sub 2}{center dot}20BaF{sub 2}, with use of the infrared radiation from a (Ga,Al)As laser diode ({lambda}=802 nm) as an excitation source. Green upconversion fluorescence due to the {sup 4}{ital S}{sub 3/2}{r arrow}{sup 4}{ital I}{sub 15/2} transition could be observed for the fluoride glass, while the fluorescence intensity for Fluorophosphate glasses decreased drastically with increasing AlPO{sub 4} content. It was found from the phonon sideband spectra of Eu{sup 3+} that the phonon with {h bar}{omega}=1060 cm{sup {minus}1}, corresponding to P-O{sup {minus}} stretching vibrations, became coupled to the multiphonon relaxation of rare-earth ions, and its electron-phonon coupling strength increased greatly with increasing phosphate content. The temperature dependence of upconversion intensity was large for the fluoride system, while it was small for the Fluorophosphate system. These tendencies could be well explained by considering the multiphonon decay rate of the Er{sup 3+} intermediate level and its temperature dependence, which are functions of the phonon energy of the host and the energy gap to the next-lower level of Er{sup 3+}. Combined with the results of {sup 151}Eu Moessbauer spectroscopy, it was concluded that themore » upconversion properties in these glasses were largely influenced by the local structure and the phonon mode coupled to the rare-earth ions.« less
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upconversion properties multiphonon relaxation and local environment of rare earth ions in Fluorophosphate glasses
Physical Review B, 1992Co-Authors: Setsuhisa Tanabe, Shigeo Yoshii, Kazuyuki Hirao, Naohiro SogaAbstract:The upconversion properties of ${\mathrm{Er}}^{3+}$ ions were studied for the Fluorophosphate glasses (45-x)${\mathrm{AlF}}_{3}$\ensuremath{\cdot}x${\mathrm{AlPO}}_{4}$\ensuremath{\cdot}${5\mathrm{E}\mathrm{r}\mathrm{F}}_{3}$\ensuremath{\cdot}${30\mathrm{C}\mathrm{a}\mathrm{F}}_{2}$\ensuremath{\cdot}${20\mathrm{B}\mathrm{a}\mathrm{F}}_{2}$, with use of the infrared radiation from a (Ga,Al)As laser diode (\ensuremath{\lambda}=802 nm) as an excitation source. Green upconversion fluorescence due to the $^{4}$${\mathit{S}}_{3/2}$${\ensuremath{\rightarrow}}^{4}$${\mathit{I}}_{15/2}$ transition could be observed for the fluoride glass, while the fluorescence intensity for Fluorophosphate glasses decreased drastically with increasing ${\mathrm{AlPO}}_{4}$ content. It was found from the phonon sideband spectra of ${\mathrm{Eu}}^{3+}$ that the phonon with \ensuremath{\Elzxh}\ensuremath{\omega}=1060 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$, corresponding to P-${\mathrm{O}}^{\mathrm{\ensuremath{-}}}$ stretching vibrations, became coupled to the multiphonon relaxation of rare-earth ions, and its electron-phonon coupling strength increased greatly with increasing phosphate content. The temperature dependence of upconversion intensity was large for the fluoride system, while it was small for the Fluorophosphate system. These tendencies could be well explained by considering the multiphonon decay rate of the ${\mathrm{Er}}^{3+}$ intermediate level and its temperature dependence, which are functions of the phonon energy of the host and the energy gap to the next-lower level of ${\mathrm{Er}}^{3+}$. Combined with the results of $^{151}\mathrm{Eu}$ M\"ossbauer spectroscopy, it was concluded that the upconversion properties in these glasses were largely influenced by the local structure and the phonon mode coupled to the rare-earth ions.
Waldemar Weber - One of the best experts on this subject based on the ideXlab platform.
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qualitative and quantitative investigation of organophosphates in an electrochemically and thermally treated lithium hexaFluorophosphate based lithium ion battery electrolyte by a developed liquid chromatography tandem quadrupole mass spectrometry method
RSC Advances, 2016Co-Authors: Vadim Kraft, Waldemar Weber, Ralf Wagner, Martin Winter, Benjamin Streipert, Carola Schultz, Sascha NowakAbstract:The presented work was focused on the development of a new liquid chromatography-tandem quadrupole mass spectrometry method (LC-MS/MS) for the identification and quantification of organophosphates in lithium hexaFluorophosphate (LiPF6)-based lithium ion battery electrolytes. The investigated electrolyte consists of 1 M LiPF6 dissolved in ethylene carbonate/ethyl methyl carbonate (50/50, wt%) and was treated electrochemically and thermally. For the electrochemical experiments, the cut-off potential in the half cells was held at 5.5 V for 72 h. The thermal degradation experiments were performed in aluminum vials at 95 °C for a period of 13 days. In the first part of this work, an already established gas chromatography-mass spectrometry (GC-MS) method for identification of dimethyl Fluorophosphates (DMFP) and diethyl Fluorophosphate (DEFP) was applied. In the second part, the LC-MS/MS method including determination of characteristic transitions in a product ion scan was developed. The developed method was applied for the identification of various analytes in the decomposed electrolytes. In addition, a possible formation of ionic and non-ionic OPs based on findings of this work and our previous reports is presented. In the third and final part, a quantification study of DMFP and DEFP was performed with a newly developed LC-MS/MS method and compared with results obtained by GC-MS. In addition, trimethyl phosphate (TMP) and triethyl phosphate (TEP) were quantified. These studies included the investigation of the suppression effects caused by the sample matrix during the application of the LC-MS/MS method.
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study of decomposition products by gas chromatography mass spectrometry and ion chromatography electrospray ionization mass spectrometry in thermally decomposed lithium hexaFluorophosphate based lithium ion battery electrolytes
RSC Advances, 2015Co-Authors: Vadim Kraft, Waldemar Weber, Martin Grutzke, Martin Winter, Sascha NowakAbstract:In this work, the thermal decomposition of a lithium ion battery electrolyte (1 M LiPF6 in ethylene carbonate/ethyl methyl carbonate, 50/50 wt%) with a focus on the formation of organophosphates was systematically studied. The quantification of non-ionic dimethyl Fluorophosphate and diethyl Fluorophosphate was performed with synthesized standards by gas chromatography-mass spectrometry. Due to absence of commercially available or synthesized standards for the monitoring of ionic methyl Fluorophosphate, ethyl Fluorophosphate and ethylene phosphate a method working with ion chromatography-electrospray ionization-mass spectrometry was developed, where dibutyl phosphate was used as an internal standard. In addition, an ion chromatography conductivity detection method with short analysis time for simultaneous determination and quantification of F−, PF6− and BF4− was developed. The formation and degradation of analytes was studied to show the dependence of different temperatures, electrolyte volumes and separator materials. The thermal aging experiments were carried out in gas-tight aluminum vials at 80 °C for three weeks. After the storage time, the samples were diluted with the appropriate analysis solvents and investigated with gas chromatography-mass spectrometry, ion chromatography and ion chromatography-electrospray ionization-mass spectrometry. Finally, the thermal degradation of the electrolyte at 85 °C after five days in aluminum and glass vials was studied.
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identification of alkylated phosphates by gas chromatography mass spectrometric investigations with different ionization principles of a thermally aged commercial lithium ion battery electrolyte
Journal of Chromatography A, 2015Co-Authors: Waldemar Weber, Vadim Kraft, Martin Grutzke, Ralf Wagner, Martin Winter, Sascha NowakAbstract:Abstract The thermal aging process of a commercial LiPF6 based lithium ion battery electrolyte has been investigated in view of the formation of volatile phosphorus-containing degradation products. Aging products were analyzed by GC–MS. Structure determination of the products was performed by support of chemical ionization MS in positive and negative modes. A fraction of the discovered compounds belongs to the group of Fluorophosphates (phosphorofluoridates) which are in suspect of potential toxicity. This is well known for relative derivatives, e.g. diisopropyl Fluorophosphate. Another fraction of the identified compounds belongs to the group of trialkyl phosphates. These compounds may provide a positive impact on the thermal and electrochemical performance of Li-based batteries as repeatedly described in the literature.
Martin Winter - One of the best experts on this subject based on the ideXlab platform.
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qualitative and quantitative investigation of organophosphates in an electrochemically and thermally treated lithium hexaFluorophosphate based lithium ion battery electrolyte by a developed liquid chromatography tandem quadrupole mass spectrometry method
RSC Advances, 2016Co-Authors: Vadim Kraft, Waldemar Weber, Ralf Wagner, Martin Winter, Benjamin Streipert, Carola Schultz, Sascha NowakAbstract:The presented work was focused on the development of a new liquid chromatography-tandem quadrupole mass spectrometry method (LC-MS/MS) for the identification and quantification of organophosphates in lithium hexaFluorophosphate (LiPF6)-based lithium ion battery electrolytes. The investigated electrolyte consists of 1 M LiPF6 dissolved in ethylene carbonate/ethyl methyl carbonate (50/50, wt%) and was treated electrochemically and thermally. For the electrochemical experiments, the cut-off potential in the half cells was held at 5.5 V for 72 h. The thermal degradation experiments were performed in aluminum vials at 95 °C for a period of 13 days. In the first part of this work, an already established gas chromatography-mass spectrometry (GC-MS) method for identification of dimethyl Fluorophosphates (DMFP) and diethyl Fluorophosphate (DEFP) was applied. In the second part, the LC-MS/MS method including determination of characteristic transitions in a product ion scan was developed. The developed method was applied for the identification of various analytes in the decomposed electrolytes. In addition, a possible formation of ionic and non-ionic OPs based on findings of this work and our previous reports is presented. In the third and final part, a quantification study of DMFP and DEFP was performed with a newly developed LC-MS/MS method and compared with results obtained by GC-MS. In addition, trimethyl phosphate (TMP) and triethyl phosphate (TEP) were quantified. These studies included the investigation of the suppression effects caused by the sample matrix during the application of the LC-MS/MS method.
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Impact of Selected LiPF6 Hydrolysis Products on the High Voltage Stability of Lithium-Ion Battery Cells
2016Co-Authors: Ralf Wagner, Benjamin Streipert, Martin Korth, Johannes Kasnatscheew, Dennis R. Gallus, Sebastian Brox, Marius Amereller, Isidora Cekic-laskovic, Martin WinterAbstract:Diverse LiPF6 hydrolysis products evolve during lithium-ion battery cell operation at elevated operation temperatures and high operation voltages. However, their impact on the formation and stability of the electrode/electrolyte interfaces is not yet investigated and understood. In this work, literature-known hydrolysis products of LiPF6 dimethyl Fluorophosphate (DMFP) and diethyl Fluorophosphate (DEFP) were synthesized and characterized. The use of DMFP and DEFP as electrolyte additive in 1 M LiPF6 in EC:EMC (1:1, by wt) was investigated in LiNi1/3Mn1/3Co1/3O2/Li half cells. When charged to a cutoff potential of 4.6 V vs Li/Li+, the additive containing cells showed improved cycling stability, increased Coulombic efficiencies, and prolonged shelf life. Furthermore, low amounts (1 wt % in this study) of the aforementioned additives did not show any negative effect on the cycling stability of graphite/Li half cells. DMFP and DEFP are susceptible to oxidation and contribute to the formation of an effective cathode/electrolyte interphase as confirmed by means of electrochemical stability window determination, and X-ray photoelectron spectroscopy characterization of pristine and cycled electrodes, and they are supported by computational calculations
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study of decomposition products by gas chromatography mass spectrometry and ion chromatography electrospray ionization mass spectrometry in thermally decomposed lithium hexaFluorophosphate based lithium ion battery electrolytes
RSC Advances, 2015Co-Authors: Vadim Kraft, Waldemar Weber, Martin Grutzke, Martin Winter, Sascha NowakAbstract:In this work, the thermal decomposition of a lithium ion battery electrolyte (1 M LiPF6 in ethylene carbonate/ethyl methyl carbonate, 50/50 wt%) with a focus on the formation of organophosphates was systematically studied. The quantification of non-ionic dimethyl Fluorophosphate and diethyl Fluorophosphate was performed with synthesized standards by gas chromatography-mass spectrometry. Due to absence of commercially available or synthesized standards for the monitoring of ionic methyl Fluorophosphate, ethyl Fluorophosphate and ethylene phosphate a method working with ion chromatography-electrospray ionization-mass spectrometry was developed, where dibutyl phosphate was used as an internal standard. In addition, an ion chromatography conductivity detection method with short analysis time for simultaneous determination and quantification of F−, PF6− and BF4− was developed. The formation and degradation of analytes was studied to show the dependence of different temperatures, electrolyte volumes and separator materials. The thermal aging experiments were carried out in gas-tight aluminum vials at 80 °C for three weeks. After the storage time, the samples were diluted with the appropriate analysis solvents and investigated with gas chromatography-mass spectrometry, ion chromatography and ion chromatography-electrospray ionization-mass spectrometry. Finally, the thermal degradation of the electrolyte at 85 °C after five days in aluminum and glass vials was studied.
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identification of alkylated phosphates by gas chromatography mass spectrometric investigations with different ionization principles of a thermally aged commercial lithium ion battery electrolyte
Journal of Chromatography A, 2015Co-Authors: Waldemar Weber, Vadim Kraft, Martin Grutzke, Ralf Wagner, Martin Winter, Sascha NowakAbstract:Abstract The thermal aging process of a commercial LiPF6 based lithium ion battery electrolyte has been investigated in view of the formation of volatile phosphorus-containing degradation products. Aging products were analyzed by GC–MS. Structure determination of the products was performed by support of chemical ionization MS in positive and negative modes. A fraction of the discovered compounds belongs to the group of Fluorophosphates (phosphorofluoridates) which are in suspect of potential toxicity. This is well known for relative derivatives, e.g. diisopropyl Fluorophosphate. Another fraction of the identified compounds belongs to the group of trialkyl phosphates. These compounds may provide a positive impact on the thermal and electrochemical performance of Li-based batteries as repeatedly described in the literature.