X-ray computed tomography in Zernike phase contrast mode at 8 keV with 50-nm resolution using Cu rotating anode X-ray source

Tkachuk, Andrei; Duewer, Fred; Cui, Hongtao; Feser, Michael; Wang, Steve; Yun, Wenbing

doi:10.1524/zkri.2007.222.11.650

Cited by 166 publications

(91 citation statements)

References 6 publications

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“…A nano-CT (UltraXRM L200, Xradia, Inc., Pleasanton, CA) was used to image the three-dimensional electrode structure with an 8 keV X-ray beam focused by a capillary condenser and Fresnel zone plate objective [24]. For imaging in the nano-CT, the electrode/Kapton film was cut to have a triangular point that would fit into the field of view and then inserted into a clip-type sample holder.…”

Section: Electrode Preparation and Nano-ctmentioning

confidence: 99%

Morphological Analyses of Polymer Electrolyte Fuel Cell Electrodes with Nano‐Scale Computed Tomography Imaging

et al. 2013

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We report a three‐dimensional (3D), pore‐scale analysis of morphological and transport properties for a polymer electrolyte fuel cell (PEFC) catalyst layer. The 3D structure of the platinum/carbon/Nafion electrode was obtained using nano‐scale resolution X‐ray computed tomography (nano‐CT). The 3D nano‐CT data was analyzed according to several morphological characteristics, with particular focus on various effective pore diameters used in modeling gas diffusion in the Knudsen transition regime, which is prevalent in PEFC catalyst layers. The pore diameter metrics include those based on chord length distributions, inscribed spheres, and surface area. Those pore diameter statistics are evaluated against computational pore‐scale diffusion simulations with local gas diffusion coefficients determined from the local pore size according to the Bosanquet formulation. According to our comparison, simulations that use local pore diameters defined by inscribed spheres provide effective diffusion coefficients that are consistent with chord‐length based estimations for an effective Knudsen length scale. By evaluating transport rates in regions of varying porosity within the nano‐CT data, we identified a Bruggeman correction scaling factor for the effective diffusivity.

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Section: Electrode Preparation and Nano-ctmentioning

confidence: 99%

Morphological Analyses of Polymer Electrolyte Fuel Cell Electrodes with Nano‐Scale Computed Tomography Imaging

et al. 2013

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“…By using focused ion beam -scanning electron microscopy (FIB-SEM) or Xray microscopy techniques, a significant progress has been made for the 3D microstructure reconstruction of conventional composite electrodes. 14,15 However, these methods are presently unable to reconstruct the infiltrated microstructures as the relative low resolutions (e.g. 10-50 nm) of these techniques are insufficient to provide microstructural information of the infiltrated nanoparticles (can be about 25 nm in radius).…”

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confidence: 99%

Geometric Properties of Nanostructured Solid Oxide Fuel Cell Electrodes

Zhang

Sun

Xia

et al. 2013

J. Electrochem. Soc.

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3D microstructures for nanostructured solid oxide fuel cell (SOFC) electrodes fabricated by infiltration/impregnation method are constructed numerically, by using a phenomenological procedure. Key geometric properties of the constructed electrodes are calculated at various infiltration loadings, including the percolation probabilities of pores and infiltrated nanoparticles, the total and active three-phase boundary (TPB) length, backbone and nanoparticles surface areas, and backbone-nanoparticles boundary area. The effects of backbone particle size, backbone porosity, nanoparticle size, and its aggregation risk are studied systematically. Analytical models are developed to predict these geometric properties, and agree well with the numerical infiltration results, as well as the literature data. It is found that the peak TPB length can be achieved at 63% coverage of the backbone surface by infiltrated nanoparticles. More interestingly, the backbone structure has little effect on nanoparticles surface area, but significantly affects TPB length, suggesting an strategy to identify electrode reaction mechanisms. Decreasing infiltrated particle size increases its surface area, enhances the peak TPB length, and decreases the optimal infiltration loading, indicating small infiltrated particles essentially benefits electrode performance. The results provide valuable information for understanding the geometric properties of the infiltrated SOFC electrodes and contribute to the design of high performance SOFC electrodes.

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“…Real-time optical inspection was used for this procedure, during which no large-scale defects were observed, thus it was concluded that the separation process did not affect the microstructure of the intended region of interest. A ZEISS Xradia 810 Ultra was then used to provide 3D images with 130 nm voxel resolution on the specimens, using a 5.4 keV quasi-monochromatic imaging system operating in absorption contrast mode [52]. Finally, the specimens were passed into the ZEISS Auriga FIB-SEM system outfitted with an Oxford Instruments X-MaxN 150 EDS spectrometer.…”

Section: Correlative Microscopy: Nano-xrm To Sem-edsmentioning

confidence: 99%

Multi-scale 3D investigations of a commercial 18650 Li-ion battery with correlative electron- and X-ray microscopy

Gelb

Finegan

Brett

et al. 2017

Journal of Power Sources

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In the present study, a commercial 18650 Li-ion cylindrical cell is investigated with nondestructive 3D X-ray microscopy across a range of length scales, beginning with a survey of the entire cell and non-destructively enlarging a smaller section. Active materials are extracted from a disassembled cell and imaging performed using a combination of sub-micron X-ray microscopy and 2D scanning-electron microscopy, which point toward the need for multi-scale analysis in order to accurately characterize the cell. Furthermore, a small section is physically isolated for 3D nano-scale X-ray microscopy, which provides a measurement of porosity and enables the effective diffusivity and 3-dimensional tortuosities to be calculated via computer simulation. Finally, the 3D X-ray microscopy data is loaded into a correlative microscopy environment, where a representative sub-surface region is identified and, subsequently, analyzed using electron microscopy and energy-dispersive X-ray spectroscopy. The results of this study elucidate the microstructural characteristics and potential degradation mechanisms of a commercial NCA battery and, further, establish a technique for extracting the Bruggeman exponent for a real-world microstructure using correlative microscopy. IntroductionThere is considerable and growing research interest in Li-ion batteries driven largely by an increase in dependence on energy storage solutions, for applications ranging from mobile electronics to stationary power supplies and electric vehicles [1][2][3]. In the coming years, increasingly demanding applications from mW to MW, will require advanced Li-ion batteries to operate under extremes of temperature, rate, and pressure. Li-ion batteries are expected to deliver high performance, over long lifetimes, at a reduced cost as compared to existing solutions. With growing dependence on Li-ion technologies, in particular due to the growing popularity of hybrid-and fully-electric vehicles [2], it is of paramount importance to understand how batteries 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 perform, age, and degrade under real-world conditions [4,5]. Recent high profile failures have emphasized the need to better understand these processes [6][7][8]. *Manuscript text (with figures and captions embedded) -clean Click here to view linked ReferencesThere are a range of Li-ion battery architectures commercially available, such as pouch, prismatic, and spiral wound cells; by far the most common geometry is the 18650 cell, which has found diverse applications from consumer electronics [9] to aerospace equipment [10] and automotive power trains [11]. While the chemistry within these cells may vary, there are common components across most available commercial cells: the functional cell comprises two porous electrodes, electrically isolated by a porous separ...

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X-ray computed tomography in Zernike phase contrast mode at 8 keV with 50-nm resolution using Cu rotating anode X-ray source

Cited by 166 publications

References 6 publications

Morphological Analyses of Polymer Electrolyte Fuel Cell Electrodes with Nano‐Scale Computed Tomography Imaging

Morphological Analyses of Polymer Electrolyte Fuel Cell Electrodes with Nano‐Scale Computed Tomography Imaging

Geometric Properties of Nanostructured Solid Oxide Fuel Cell Electrodes

Multi-scale 3D investigations of a commercial 18650 Li-ion battery with correlative electron- and X-ray microscopy

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