2016
Journal Articles
7.
Pattarachai Srimuk; Friedrich Kaasik; Benjamin Krüner; Aura Tolosa; Simon Fleischmann; Nicolas Jäckel; Mehmet C. Tekeli; Mesut Aslan; Matthew E. Suss; Volker Presser
MXene as a novel intercalation-type pseudocapacitive cathode and anode for capacitive deionization Journal Article
In: Journal of Materials Chemistry A, vol. 4, pp. 18265-18271, 2016.
@article{Srimuk2016b,
title = {MXene as a novel intercalation-type pseudocapacitive cathode and anode for capacitive deionization},
author = {Pattarachai Srimuk and Friedrich Kaasik and Benjamin Krüner and Aura Tolosa and Simon Fleischmann and Nicolas Jäckel and Mehmet C. Tekeli and Mesut Aslan and Matthew E. Suss and Volker Presser},
doi = {10.1039/C6TA07833H},
year = {2016},
date = {2016-11-02},
urldate = {2016-11-02},
journal = {Journal of Materials Chemistry A},
volume = {4},
pages = {18265-18271},
abstract = {In this proof-of-concept study, we introduce and demonstrate MXene as a novel type of intercalation electrode for desalination via capacitive deionization (CDI). Traditional CDI cells employ nanoporous carbon electrodes with significant pore volume to achieve a large desalination capacity via ion electrosorption. By contrast, MXene stores charge by ion intercalation between the sheets of its two-dimensional nanolamellar structure. By this virtue, it behaves as an ideal pseudocapacitor, that is, showing capacitive electric response while intercalating both anions and cations. We synthesized Ti3C2-MXene by the conventional process of etching ternary titanium aluminum carbide i.e., the MAX phase (Ti3AlC2) with hydrofluoric acid. The MXene material was cast directly onto the porous separator of the CDI cell without added binder, and exhibited very stable performance over 30 CDI cycles with an average salt adsorption capacity of 13 ± 2 mg g−1.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this proof-of-concept study, we introduce and demonstrate MXene as a novel type of intercalation electrode for desalination via capacitive deionization (CDI). Traditional CDI cells employ nanoporous carbon electrodes with significant pore volume to achieve a large desalination capacity via ion electrosorption. By contrast, MXene stores charge by ion intercalation between the sheets of its two-dimensional nanolamellar structure. By this virtue, it behaves as an ideal pseudocapacitor, that is, showing capacitive electric response while intercalating both anions and cations. We synthesized Ti3C2-MXene by the conventional process of etching ternary titanium aluminum carbide i.e., the MAX phase (Ti3AlC2) with hydrofluoric acid. The MXene material was cast directly onto the porous separator of the CDI cell without added binder, and exhibited very stable performance over 30 CDI cycles with an average salt adsorption capacity of 13 ± 2 mg g−1.
6.
Pattarachai Srimuk; Lucie Ries; Marco Zeiger; Simon Fleischmann; Nicolas Jäckel; Aura Tolosa; Benjamin Krüner; Mesut Aslan; Volker Presser
High performance stability of titania decorated carbon for desalination with capacitive deionization in oxygenated water Journal Article
In: RSC Advances, vol. 6, pp. 106081-106089, 2016.
@article{Srimuk2016,
title = {High performance stability of titania decorated carbon for desalination with capacitive deionization in oxygenated water},
author = {Pattarachai Srimuk and Lucie Ries and Marco Zeiger and Simon Fleischmann and Nicolas Jäckel and Aura Tolosa and Benjamin Krüner and Mesut Aslan and Volker Presser},
doi = {10.1039/C6RA22800C},
year = {2016},
date = {2016-11-01},
urldate = {2016-11-01},
journal = {RSC Advances},
volume = {6},
pages = {106081-106089},
abstract = {Performance stability in capacitive deionization (CDI) is particularly challenging in systems with a high amount of dissolved oxygen due to rapid oxidation of the carbon anode and peroxide formation. For example, carbon electrodes show a fast performance decay, leading to just 15% of the initial performance after 50 CDI cycles in oxygenated saline solution (5 mM NaCl). We present a novel strategy to overcome this severe limitation by employing nanocarbon particles hybridized with sol–gel-derived titania. In our proof-of-concept study, we demonstrate very stable performance in low molar saline electrolyte (5 mM NaCl) with saturated oxygen for the carbon/metal oxide hybrid (90% of the initial salt adsorption capacity after 100 cycles). The electrochemical analysis using a rotating disk electrode (RDE) confirms the oxygen reduction reaction (ORR) catalytic effect of FW200/TiO2, preventing local peroxide formation by locally modifying the oxygen reduction reaction.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Performance stability in capacitive deionization (CDI) is particularly challenging in systems with a high amount of dissolved oxygen due to rapid oxidation of the carbon anode and peroxide formation. For example, carbon electrodes show a fast performance decay, leading to just 15% of the initial performance after 50 CDI cycles in oxygenated saline solution (5 mM NaCl). We present a novel strategy to overcome this severe limitation by employing nanocarbon particles hybridized with sol–gel-derived titania. In our proof-of-concept study, we demonstrate very stable performance in low molar saline electrolyte (5 mM NaCl) with saturated oxygen for the carbon/metal oxide hybrid (90% of the initial salt adsorption capacity after 100 cycles). The electrochemical analysis using a rotating disk electrode (RDE) confirms the oxygen reduction reaction (ORR) catalytic effect of FW200/TiO2, preventing local peroxide formation by locally modifying the oxygen reduction reaction.
5.
Marco Zeiger; Teguh Ariyanto; Benjamin Krüner; Nicolas J Peter; Simon Fleischmann; Bastian J.M. Etzold; Volker Presser
Vanadium pentoxide/carbide-derived carbon core–shell hybrid particles for high performance electrochemical energy storage Journal Article
In: Journal of Materials Chemistry A, vol. 4, pp. 18899-18909, 2016.
@article{Zeiger2016b,
title = {Vanadium pentoxide/carbide-derived carbon core–shell hybrid particles for high performance electrochemical energy storage},
author = {Marco Zeiger and Teguh Ariyanto and Benjamin Krüner and Nicolas J Peter and Simon Fleischmann and Bastian J.M. Etzold and Volker Presser},
doi = {10.1039/C6TA08900C},
year = {2016},
date = {2016-10-31},
journal = {Journal of Materials Chemistry A},
volume = {4},
pages = {18899-18909},
abstract = {A novel, two step synthesis is presented combining the formation of carbide-derived carbon (CDC) and redox-active vanadium pentoxide (V2O5) in a core–shell manner using solely vanadium carbide (VC) as the precursor. In a first step, the outer part of VC particles is transformed to nanoporous CDC owing to the in situ formation of chlorine gas from NiCl2 at 700 °C. In a second step, the remaining VC core is calcined in synthetic air to obtain V2O5/CDC core–shell particles. Materials characterization by means of electron microscopy, Raman spectroscopy, and X-ray diffraction clearly demonstrates the partial transformation from VC to CDC, as well as the successive oxidation to V2O5/CDC core–shell particles. Electrochemical performance was tested in organic 1 M LiClO4 in acetonitrile using half- and asymmetric full-cell configuration. High specific capacities of 420 mA h g−1 (normalized to V2O5) and 310 mA h g−1 (normalized to V2O5/CDC) were achieved. The unique nanotextured core–shell architecture enables high power retention with ultrafast charging and discharging, achieving more than 100 mA h g−1 at 5 A g−1 (rate of 12C). Asymmetric cell design with CDC on the positive polarization side leads to a high specific energy of up to 80 W h kg−1 with a superior retention of more than 80% over 10 000 cycles and an overall energy efficiency of up to 80% at low rates.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A novel, two step synthesis is presented combining the formation of carbide-derived carbon (CDC) and redox-active vanadium pentoxide (V2O5) in a core–shell manner using solely vanadium carbide (VC) as the precursor. In a first step, the outer part of VC particles is transformed to nanoporous CDC owing to the in situ formation of chlorine gas from NiCl2 at 700 °C. In a second step, the remaining VC core is calcined in synthetic air to obtain V2O5/CDC core–shell particles. Materials characterization by means of electron microscopy, Raman spectroscopy, and X-ray diffraction clearly demonstrates the partial transformation from VC to CDC, as well as the successive oxidation to V2O5/CDC core–shell particles. Electrochemical performance was tested in organic 1 M LiClO4 in acetonitrile using half- and asymmetric full-cell configuration. High specific capacities of 420 mA h g−1 (normalized to V2O5) and 310 mA h g−1 (normalized to V2O5/CDC) were achieved. The unique nanotextured core–shell architecture enables high power retention with ultrafast charging and discharging, achieving more than 100 mA h g−1 at 5 A g−1 (rate of 12C). Asymmetric cell design with CDC on the positive polarization side leads to a high specific energy of up to 80 W h kg−1 with a superior retention of more than 80% over 10 000 cycles and an overall energy efficiency of up to 80% at low rates.
4.
Marco Zeiger; Simon Fleischmann; Benjamin Krüner; Aura Tolosa; Stephan Bechtel; Mathias Baltes; Anna Schreiber; Riko Moroni; Severin Vierrath; Simon Thiele; Volker Presser
Influence of carbon substrate on the electrochemical performance of carbon/manganese oxide hybrids in aqueous and organic electrolytes Journal Article
In: RSC Advances, vol. 6, pp. 107163-107179, 2016.
@article{Zeiger2016,
title = {Influence of carbon substrate on the electrochemical performance of carbon/manganese oxide hybrids in aqueous and organic electrolytes},
author = {Marco Zeiger and Simon Fleischmann and Benjamin Krüner and Aura Tolosa and Stephan Bechtel and Mathias Baltes and Anna Schreiber and Riko Moroni and Severin Vierrath and Simon Thiele and Volker Presser},
doi = {10.1039/C6RA24181F},
year = {2016},
date = {2016-10-25},
urldate = {2016-10-25},
journal = {RSC Advances},
volume = {6},
pages = {107163-107179},
abstract = {Manganese oxide presents very promising electrochemical properties as an electrode material in supercapacitors, but there remain important open questions to guide further development of the complex manganese oxide/carbon/electrolyte system. Our work addresses specifically the influence of carbon ordering and the difference between outer and inner porosity of carbon particles for the application in aqueous 1 M Na2SO4 and 1 M LiClO4 in acetonitrile. Birnessite-type manganese oxide was hydrothermally hybridized on two kinds of carbon onions with only outer surface area and different electrical conductivity, and conventional activated carbon with a high inner porosity. Carbon onions with a high degree of carbon ordering, high conductivity, and high outer surface area were identified as the most promising material, yielding 179 F g−1. Pore blocking in activated carbon yields unfavorable electrochemical performances. The highest specific energy of 16.4 W h kg−1 was measured for a symmetric full-cell arrangement of manganese oxide coated high temperature carbon onions in the organic electrolyte. High stability during 10 000 cycles was achieved for asymmetric full-cells, which proved as a facile way to enhance the electrochemical performance stability.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Manganese oxide presents very promising electrochemical properties as an electrode material in supercapacitors, but there remain important open questions to guide further development of the complex manganese oxide/carbon/electrolyte system. Our work addresses specifically the influence of carbon ordering and the difference between outer and inner porosity of carbon particles for the application in aqueous 1 M Na2SO4 and 1 M LiClO4 in acetonitrile. Birnessite-type manganese oxide was hydrothermally hybridized on two kinds of carbon onions with only outer surface area and different electrical conductivity, and conventional activated carbon with a high inner porosity. Carbon onions with a high degree of carbon ordering, high conductivity, and high outer surface area were identified as the most promising material, yielding 179 F g−1. Pore blocking in activated carbon yields unfavorable electrochemical performances. The highest specific energy of 16.4 W h kg−1 was measured for a symmetric full-cell arrangement of manganese oxide coated high temperature carbon onions in the organic electrolyte. High stability during 10 000 cycles was achieved for asymmetric full-cells, which proved as a facile way to enhance the electrochemical performance stability.
3.
Aura Tolosa; Benjamin Krüner; Simon Fleischmann; Nicolas Jäckel; Marco Zeiger; Mesut Aslan; Ingrid Grobelsek; Volker Presser
Niobium carbide nanofibers as a versatile precursor for high power supercapacitor and high energy battery electrodes Journal Article
In: J. Mater. Chem. A, vol. 4, pp. 16003-16016, 2016.
@article{Tolosa2016,
title = {Niobium carbide nanofibers as a versatile precursor for high power supercapacitor and high energy battery electrodes},
author = {Aura Tolosa and Benjamin Krüner and Simon Fleischmann and Nicolas Jäckel and Marco Zeiger and Mesut Aslan and Ingrid Grobelsek and Volker Presser},
doi = {10.1039/C6TA06224E},
year = {2016},
date = {2016-07-22},
urldate = {2016-07-22},
journal = {J. Mater. Chem. A},
volume = {4},
pages = {16003-16016},
abstract = {This study presents electrospun niobium carbide/carbon (NbC/C) hybrid nanofibers, with an average diameter of 69 ± 30 nm, as a facile precursor to derive either highly nanoporous niobium carbide-derived carbon (NbC–CDC) fibers for supercapacitor applications or niobium pentoxide/carbon (Nb2O5/C) hybrid fibers for battery-like energy storage. In all cases, the electrodes consist of binder-free and free-standing nanofiber mats that can be used without further conductive additives. Chlorine gas treatment conformally transforms NbC nanofiber mats into NbC–CDC fibers with a specific surface area of 1508 m2 g−1. These nanofibers show a maximum specific energy of 19.5 W h kg−1 at low power and 7.6 W h kg−1 at a high specific power of 30 kW kg−1 in an organic electrolyte. CO2 treatment transforms NbC into T-Nb2O5/C hybrid nanofiber mats that provide a maximum capacity of 156 mA h g−1. The presence of graphitic carbon in the hybrid nanofibers enabled high power handling, maintaining 50% of the initial energy storage capacity at a high rate of 10 A g−1 (64 C-rate). When benchmarked for an asymmetric full-cell, a maximum specific energy of 86 W h kg−1 was obtained. The high specific power for both systems, NbC–CDC and T-Nb2O5/C, resulted from the excellent charge propagation in the continuous nanofiber network and the high graphitization of the carbon structure.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
This study presents electrospun niobium carbide/carbon (NbC/C) hybrid nanofibers, with an average diameter of 69 ± 30 nm, as a facile precursor to derive either highly nanoporous niobium carbide-derived carbon (NbC–CDC) fibers for supercapacitor applications or niobium pentoxide/carbon (Nb2O5/C) hybrid fibers for battery-like energy storage. In all cases, the electrodes consist of binder-free and free-standing nanofiber mats that can be used without further conductive additives. Chlorine gas treatment conformally transforms NbC nanofiber mats into NbC–CDC fibers with a specific surface area of 1508 m2 g−1. These nanofibers show a maximum specific energy of 19.5 W h kg−1 at low power and 7.6 W h kg−1 at a high specific power of 30 kW kg−1 in an organic electrolyte. CO2 treatment transforms NbC into T-Nb2O5/C hybrid nanofiber mats that provide a maximum capacity of 156 mA h g−1. The presence of graphitic carbon in the hybrid nanofibers enabled high power handling, maintaining 50% of the initial energy storage capacity at a high rate of 10 A g−1 (64 C-rate). When benchmarked for an asymmetric full-cell, a maximum specific energy of 86 W h kg−1 was obtained. The high specific power for both systems, NbC–CDC and T-Nb2O5/C, resulted from the excellent charge propagation in the continuous nanofiber network and the high graphitization of the carbon structure.
2.
Simon Fleischmann; Nicolas Jäckel; Marco Zeiger; Benjamin Krüner; Ingrid Grobelsek; Petr Formanek; Soumyadip Choudhury; Daniel Weingarth; Volker Presser
In: Chemistry of Materials, vol. 28, pp. 2802–2813, 2016.
@article{Fleischmann2016,
title = {Enhanced electrochemical energy storage by nanoscopic decoration of endohedral and exohedral carbon with vanadium oxide via atomic layer deposition},
author = {Simon Fleischmann and Nicolas Jäckel and Marco Zeiger and Benjamin Krüner and Ingrid Grobelsek and Petr Formanek and Soumyadip Choudhury and Daniel Weingarth and Volker Presser},
doi = {10.1021/acs.chemmater.6b00738},
year = {2016},
date = {2016-05-28},
urldate = {2016-05-28},
journal = {Chemistry of Materials},
volume = {28},
pages = {2802–2813},
abstract = {Atomic layer deposition (ALD) is a facile process to decorate carbon surfaces with redox-active nanolayers. This is a particularly attractive route to obtain hybrid electrode materials for high performance electrochemical energy storage applications. Using activated carbon and carbon onions as representatives of substrate materials with large internal or external surface area, respectively, we have studied the enhanced energy storage capacity of vanadium oxide coatings. While the internal porosity of activated carbon readily becomes blocked by obstructing nanopores, carbon onions enable the continued deposition of vanadia within their large interparticle voids. Electrochemical benchmarking in lithium perchlorate in acetonitrile (1 M LiClO4) showed a maximum capacity of 122 mAh/g when using vanadia coated activated carbon and 129 mAh/g for vanadia coated carbon onions. There is an optimum amount of vanadia between 50 and 65 wt % for both substrates that results in an ideal balance between redox-activity and electrical conductivity of the hybrid electrode. Assembling asymmetric (charge balanced) full-cells, a maximum specific energy of 38 Wh/kg and 29 Wh/kg was found for carbon onions and activated carbon, respectively. The stability of both systems is promising, with a capacity retention of ∼85–91% after 7000 cycles for full-cell measurements.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Atomic layer deposition (ALD) is a facile process to decorate carbon surfaces with redox-active nanolayers. This is a particularly attractive route to obtain hybrid electrode materials for high performance electrochemical energy storage applications. Using activated carbon and carbon onions as representatives of substrate materials with large internal or external surface area, respectively, we have studied the enhanced energy storage capacity of vanadium oxide coatings. While the internal porosity of activated carbon readily becomes blocked by obstructing nanopores, carbon onions enable the continued deposition of vanadia within their large interparticle voids. Electrochemical benchmarking in lithium perchlorate in acetonitrile (1 M LiClO4) showed a maximum capacity of 122 mAh/g when using vanadia coated activated carbon and 129 mAh/g for vanadia coated carbon onions. There is an optimum amount of vanadia between 50 and 65 wt % for both substrates that results in an ideal balance between redox-activity and electrical conductivity of the hybrid electrode. Assembling asymmetric (charge balanced) full-cells, a maximum specific energy of 38 Wh/kg and 29 Wh/kg was found for carbon onions and activated carbon, respectively. The stability of both systems is promising, with a capacity retention of ∼85–91% after 7000 cycles for full-cell measurements.
2015
Journal Articles
1.
Andreas Rosenkranz; Simon Fleischmann; Carsten Gachot; Frank Mücklich
Anisotropic Spreading Behavior of PAO Oil on Laser‐Patterned Stainless Steel Surfaces Journal Article
In: Advanced Engineering Materials, vol. 17, pp. 1645-1651, 2015.
@article{Rosenkranz2015,
title = {Anisotropic Spreading Behavior of PAO Oil on Laser‐Patterned Stainless Steel Surfaces},
author = {Andreas Rosenkranz and Simon Fleischmann and Carsten Gachot and Frank Mücklich},
doi = {10.1002/adem.201500115},
year = {2015},
date = {2015-05-01},
urldate = {2015-05-01},
journal = {Advanced Engineering Materials},
volume = {17},
pages = {1645-1651},
abstract = {In this experimental study, periodic line-like structures with different periodicities (5 and 10 µm) were fabricated by laser interference patterning on stainless steel samples (AISI-304). A detailed characterization of the resulting surface topography was performed by white light interferometry using typical roughness parameters and the power spectral density plot. By means of the power spectral density, the homogeneity of the patterned surfaces was determined. Afterwards the resulting anisotropic spreading behavior of an oil droplet being a Poly-(alpha)-olefin with a relatively small kinematic viscosity (7.8 cSt at 100 °C) surfaces was investigated on the laser-patterned steel. The droplet motion was recorded by a digital light microscope. Finally, the droplet length and width were measured at 6 different times after deposition (1, 2, 5, 10, 20 and 60 s) and the droplet distortion was calculated. From this study, it can be concluded that the periodicity of the pattern and consequently the aspect ratio are the most influencing factors with regard to the anisotropic spreading behavior. Surface patterns having smaller periodicities and larger aspect ratios lead to a larger droplet distortion whereas the homogeneity of the pattern plays a minor role. Thus, the presented method is suitable to adjust the spreading characteristics of lubricants on metallic surfaces for controlled oil support in tribologically loaded contacts.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this experimental study, periodic line-like structures with different periodicities (5 and 10 µm) were fabricated by laser interference patterning on stainless steel samples (AISI-304). A detailed characterization of the resulting surface topography was performed by white light interferometry using typical roughness parameters and the power spectral density plot. By means of the power spectral density, the homogeneity of the patterned surfaces was determined. Afterwards the resulting anisotropic spreading behavior of an oil droplet being a Poly-(alpha)-olefin with a relatively small kinematic viscosity (7.8 cSt at 100 °C) surfaces was investigated on the laser-patterned steel. The droplet motion was recorded by a digital light microscope. Finally, the droplet length and width were measured at 6 different times after deposition (1, 2, 5, 10, 20 and 60 s) and the droplet distortion was calculated. From this study, it can be concluded that the periodicity of the pattern and consequently the aspect ratio are the most influencing factors with regard to the anisotropic spreading behavior. Surface patterns having smaller periodicities and larger aspect ratios lead to a larger droplet distortion whereas the homogeneity of the pattern plays a minor role. Thus, the presented method is suitable to adjust the spreading characteristics of lubricants on metallic surfaces for controlled oil support in tribologically loaded contacts.