Direct Laser Interference Patterning(DLIP)is used to texture current collector foils in a roll-to-roll process using a high-power picosecond pulsed laser system operating at either fundamental wavelength of 1064 nm or...Direct Laser Interference Patterning(DLIP)is used to texture current collector foils in a roll-to-roll process using a high-power picosecond pulsed laser system operating at either fundamental wavelength of 1064 nm or 2nd harmonic of 532 nm.The raw beam having a diameter of 3 mm@1/e^(2) is shaped into an elongated top-hat intensity profile using a diffractive so-called FBS■-L element and cylindrical telescopes.The shaped beam is split into its diffraction orders,where the two first orders are parallelized and guided into a galvanometer scanner.The deflected beams inside the scan head are recombined with an F-theta objective on the working position generating the interference pattern.The DLIP spot has a line-like interference pattern with about 15μm spatial period.Laser fluences of up to 8 J cm^(-2) were achieved using a maximum pulse energy of 0.6 mJ.Furthermore,an in-house built roll-to-roll machine was developed.Using this setup,aluminum and copper foil of 20μm and 9μm thickness,respectively,could be processed.Subsequently to current collector structuring coating of composite electrode material took place.In case of lithium nickel manganese cobalt oxide(NMC 622)cathode deposited onto textured aluminum current collector,an increased specific discharge capacity could be achieved at a C-rate of 1℃.For the silicon/graphite anode material deposited onto textured copper current collector,an improved rate capability at all C-rates between C/10 and 5℃ was achieved.The rate capability was increased up to 100%compared to reference material.At C-rates between C/2 and 2℃,the specific discharge capacity was increased to 200 mAh g^(-1),while the reference electrodes with untextured current collector foils provided a specific discharge capacity of 100 m Ah g^(-1),showing the potential of the DLIP technology for cost-effective production of battery cells with increased cycle lifetime.展开更多
Carbon nanoparticle coatings on laser-patterned stainless-steel surfaces present a solid lubrication system where the pattern's recessions act as lubricant-retaining reservoirs.This study investigates the influenc...Carbon nanoparticle coatings on laser-patterned stainless-steel surfaces present a solid lubrication system where the pattern's recessions act as lubricant-retaining reservoirs.This study investigates the influence of the structural depth of line patterns coated with multi-walled carbon nanotubes(CNTs)and carbon onions(COs)on their respective potential to reduce friction and wear.Direct laser interference patterning(DLIP)with a pulse duration of 12 ps is used to create line patterns with three different structural depths at a periodicity of 3.5μm on AISI 304 steel platelets.Subsequently,electrophoretic deposition(EPD)is applied to form homogeneous carbon nanoparticle coatings on the patterned platelets.Tribological ball-on-disc experiments are conducted on the as-described surfaces with an alumina counter body at a load of 100 mN.The results show that the shallower the coated structure,the lower its coefficient of friction(COF),regardless of the particle type.Thereby,with a minimum of just below 0.20,CNTs reach lower COF values than COs over most of the testing period.The resulting wear tracks are characterized by scanning electron microscopy,transmission electron microscopy,and energy-dispersive X-ray spectroscopy.During friction testing,the CNTs remain in contact,and the immediate proximity,whereas the CO coating is largely removed.Regardless of structural depth,no oxidation occurs on CNT-coated surfaces,whereas minor oxidation is detected on CO-coated wear tracks.展开更多
基金funded by the German Federal Ministry of Education and Research(BMBF),project NextGen-3DBat,Grant Number 03XP0198Fby the Fraunhofer Cluster of Excellence Advanced Photon Sources(CAPS)。
文摘Direct Laser Interference Patterning(DLIP)is used to texture current collector foils in a roll-to-roll process using a high-power picosecond pulsed laser system operating at either fundamental wavelength of 1064 nm or 2nd harmonic of 532 nm.The raw beam having a diameter of 3 mm@1/e^(2) is shaped into an elongated top-hat intensity profile using a diffractive so-called FBS■-L element and cylindrical telescopes.The shaped beam is split into its diffraction orders,where the two first orders are parallelized and guided into a galvanometer scanner.The deflected beams inside the scan head are recombined with an F-theta objective on the working position generating the interference pattern.The DLIP spot has a line-like interference pattern with about 15μm spatial period.Laser fluences of up to 8 J cm^(-2) were achieved using a maximum pulse energy of 0.6 mJ.Furthermore,an in-house built roll-to-roll machine was developed.Using this setup,aluminum and copper foil of 20μm and 9μm thickness,respectively,could be processed.Subsequently to current collector structuring coating of composite electrode material took place.In case of lithium nickel manganese cobalt oxide(NMC 622)cathode deposited onto textured aluminum current collector,an increased specific discharge capacity could be achieved at a C-rate of 1℃.For the silicon/graphite anode material deposited onto textured copper current collector,an improved rate capability at all C-rates between C/10 and 5℃ was achieved.The rate capability was increased up to 100%compared to reference material.At C-rates between C/2 and 2℃,the specific discharge capacity was increased to 200 mAh g^(-1),while the reference electrodes with untextured current collector foils provided a specific discharge capacity of 100 m Ah g^(-1),showing the potential of the DLIP technology for cost-effective production of battery cells with increased cycle lifetime.
基金financial support by the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)within the project MU 959/47-1Furthermore,the authors gratefully acknowledge funding in the ZuMat projectsupported by the State of Saarland from the European Regional Development Fund(Europäischer Fonds für Regionale Entwicklung,EFRE).P.Grützmacher and C.Gachot would like to thank the Government of Lower Austria(WST3)for financially supporting the endowed professorship tribology at the TU Wien.V.Presser thanks Eduard Arzt(INM)for his continuing support.
文摘Carbon nanoparticle coatings on laser-patterned stainless-steel surfaces present a solid lubrication system where the pattern's recessions act as lubricant-retaining reservoirs.This study investigates the influence of the structural depth of line patterns coated with multi-walled carbon nanotubes(CNTs)and carbon onions(COs)on their respective potential to reduce friction and wear.Direct laser interference patterning(DLIP)with a pulse duration of 12 ps is used to create line patterns with three different structural depths at a periodicity of 3.5μm on AISI 304 steel platelets.Subsequently,electrophoretic deposition(EPD)is applied to form homogeneous carbon nanoparticle coatings on the patterned platelets.Tribological ball-on-disc experiments are conducted on the as-described surfaces with an alumina counter body at a load of 100 mN.The results show that the shallower the coated structure,the lower its coefficient of friction(COF),regardless of the particle type.Thereby,with a minimum of just below 0.20,CNTs reach lower COF values than COs over most of the testing period.The resulting wear tracks are characterized by scanning electron microscopy,transmission electron microscopy,and energy-dispersive X-ray spectroscopy.During friction testing,the CNTs remain in contact,and the immediate proximity,whereas the CO coating is largely removed.Regardless of structural depth,no oxidation occurs on CNT-coated surfaces,whereas minor oxidation is detected on CO-coated wear tracks.
