Showing papers on "Power density published in 2000"

Ultracapacitors: Why, How, and Where is the Technology

Abstract: The science and technology of ultracapacitors are reviewed for a number of electrode materials, including carbon, mixed metal oxides, and conducting polymers. More work has been done using microporous carbons than with the other materials and most of the commercially available devices use carbon electrodes and an organic electrolytes. The energy density of these devices is 3¯5 Wh/kg with a power density of 300¯500 W/kg for high efficiency (90¯95%) charge/discharges. Projections of future developments using carbon indicate that energy densities of 10 Wh/kg or higher are likely with power densities of 1¯2 kW/kg. A key problem in the fabrication of these advanced devices is the bonding of the thin electrodes to a current collector such the contact resistance is less than 0.1 cm2. Special attention is given in the paper to comparing the power density characteristics of ultracapacitors and batteries. The comparisons should be made at the same charge/discharge efficiency.

A low-operating-temperature solid oxide fuel cell in hydrocarbon-Air mixtures

Abstract: The performance of a single-chamber solid oxide fuel cell was studied using a ceria-based solid electrolyte at temperatures below 773 kelvin. Electromotive forces of ∼900 millivolts were generated from the cell in a flowing mixture of ethane or propane and air, where the solid electrolyte functioned as a purely ionic conductor. The electrode-reaction resistance was negligibly small in the total internal resistances of the cell. The resulting peak power density reached 403 and 101 milliwatts per square centimeter at 773 and 623 kelvin, respectively.

Trench fill with HDP-CVD process including coupled high power density plasma deposition

Abstract: A trench-fill material is deposited to fill a trench in a substrate disposed in a process chamber An inert gas is introduced into the process chamber and a plasma is formed to heat the substrate to a preset temperature, which is typically the temperature at which deposition of the trench-fill material is to take place The plasma is terminated upon reaching the preset temperature for the substrate A process gas is then flowed into the process chamber without plasma excitation until the process gas flow and distribution achieve a generally steady state in the process chamber A plasma is then formed to deposit the trench-fill material on the surface of the substrate and fill the trench By establishing generally steady state conditions in the chamber prior to deposition, transient effects are reduced and more uniform deposition of the trench-fill material is obtained The step of forming the plasma typically includes coupling source plasma energy into the process chamber at a total power density of at least about 15 Watts/cm2 The energy is inductively coupled into the process chamber by coupling a top coil with a top portion of the process chamber above the surface of the substrate and coupling a side coil with a side portion of the process chamber generally surrounding the side edge of the substrate The top coil is powered at a top RF power level to produce a top power density and the side coil is-powered at a side RF power level to produce a side power density The total RF power density is equal to the sum of the top and side power densities The top power density and the side power density desirably have a ratio of at least about 15 The high source plasma power density generates a high ion density plasma and produces a more directional deposition, and a higher top power density relative to the side power density produces a more uniform plasma over the substrate, resulting in improved trench fill, particularly for aggressive trenches having aspect ratios of about 3:1 to 4:1 The process gas typically includes silicon, oxygen, and an inert component having a concentration of less than about 40%, by volume In specific embodiments, the concentration of the inert component is equal to about 0%

Coreless planar printed-circuit-board (PCB) transformers-a fundamental concept for signal and energy transfer

Abstract: Magnetic cores have been used in transformers for over a century. In this paper, the authors present a fundamental concept of using "coreless" printed-circuit-board (PCB) transformers. With the aid of a high-frequency equivalent circuit, the use and basic characteristics of coreless PCB transformers are described. Optimal operating conditions for minimum input power requirement and maximum efficiency operations are identified. Coreless PCB transformers have the advantages of low costs, very high power density, no limitation due to magnetic cores, no magnetic loss and ease of manufacturing. They have the potential to be developed in microcircuits. A printed planar PCB transformer with a diameter of about 1.0 cm and power capability of 19 W has been successfully tested. The power density of the PCB transformer demonstrated in this paper is 24 W/cm/sup 2/. The maximum efficiency can be greater than 90%. The analysis has been confirmed with experiments. Coreless printed transformers have great potential in applications in which stringent height and space requirements have to be met.

Properties of ITO thin films deposited by RF magnetron sputtering at elevated substrate temperature

Abstract: Indium tin oxide films have been deposited by RF magnetron sputtering technique. Discharge power density has been varied from 0.36 to 2 W cm−2 and pure argon or argon/oxygen mixture have been utilised as sputtering gas. Substrate temperature has been kept at 250°C for all the samples. Film's crystallisation behaviour has been investigated as a function of RF power density. XRD analysis revealed a change in preferential orientation of polycrystalline crystalline structure from (222) to (400) plane with the increase in RF power. Crystallite size was found to increase with the RF power. EPMA analysis revealed a higher O/In ratio in the 〈111〉 oriented samples than in the 〈100〉 oriented ones. In/Sn ratio, evaluated by ICP analysis, decreased with the increase in RF power and with the change of sputtering gas from pure Ar to Ar/O2 mixture. Optical band gap was found continuously decreasing with the increase in RF power. Hall effect measurement showed the influence of high deposition power on the electron mobility degradation. A very low electrical resistivity of 8.6×10−5 Ω cm−1 was achieved during this investigation. A close correlation between the preferential orientation and film properties has been pointed out.

Intermediate Temperature Solid Oxide Fuel Cells Using LaGaO3 Electrolyte II. Improvement of Oxide Ion Conductivity and Power Density by Doping Fe for Ga Site of LaGaO3

Abstract: Effects of small amounts of Fe doping for Ga site in LaGaO 3 -based oxide on oxide ion conductivity is investigated in this study. It is found that doping a small amount of Fe is effective for improving the oxide ion conductivity in La 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O 3 (LSGM). The highest oxide ion conductivity was exhibited at x = 0.03 in La 0.8 Sr 0.2 Ga 0.8 Mg 0.2-x Fe x O 3 among the Fe-doped samples. Electron spin resonance (ESR) measurements suggest that Fe is trivalent in LaGaO 3 lattice. The application of the Fe-doped LaGaO 3 -based oxide for the electrolyte of solid oxide fuel cell was further investigated. Power density of the solid oxide fuel cell was increased by using Fe-doped LSGM for electrolyte. This can be explained by the decrease in electrical resistance loss by improving the oxide ion conductivity. A maximum power density close to 700 mW/cm 2 was obtained at 1073 K on the cell using 0.5 mm thick La 0.8 Sr 0.2 Ga 0.8 Mg 0-17 Fe 0.03 O 3 (LSGMF) and O 2 as the electrolyte and the oxidant, respectively. Therefore, close to the theoretical open-circuit potential was exhibited by the LSGMF cell. On the other hand, the power density was slightly smaller than that of the cell using Co-doped LSGM as electrolyte, especially, at temperatures lower than 973 K. This may result from the large activation energy for ion conductivity. However, the power density of the LSGMF cell was higher than that of the LSGM cell. Therefore, LSGM doped with a small amount of Fe is a promising electrolyte similar to Co-doped LSGM for the intermediate solid oxide fuel cell.

Effect of distance on the power density from two light guides

Abstract: Purpose: This study determined the effect of distance on the power density from standard and Turbo light guides (Demetron/Kerr, Danbury, Connecticut). Materials and Methods: Power density was measured from 0 to 10 mm away from the tip of standard 8-mm curved light guides and 13/8-mm Turbo curved light guides. To determine the effect of distance on power density, a polynomial regression line was fitted. The Kolmogorov-Smirnov (K-S) statistic and the Wilcoxon rank sum (WR) tests were used to determine if there was a difference in the rate at which the power density decreased for the standard and Turbo light guides as the distance from the tip increased. Photographs of the light dispersion from each tip were also taken. Results: At 0 mm, the mean (± SD) power density from the two standard light guides was 743 ± 6.1 mW/cm2 and from the four Turbo light guides was 1128 ± 22.1 mW/cm2. As the distance from the tip of the light-guide tip increased, the power density decreased, but the rate of decrease was greater from the Turbo light guides than from the standard light guides. At 6 mm the power density from the standard light guides fell to 372 mW/cm2 (50% of the original value) and the power density from the Turbo light guides fell to 263 mW/cm2 (23% of the original value). Both the K-S statistic and the WR sum test indicated that the distribution of light intensities was significantly different from the two light guides (WR p-value = .0246, K-S p-value < .0001). The two estimated polynomials intersected at 3.66 mm, and the 95% prediction intervals intersected at about 2.8 and 4.8 mm. Therefore, beyond 5 mm away from the tip of the light guide, the standard light guides gave higher power density readings than the Turbo light guides. Photographs showed that the light dispersed at a wider angle from the Turbo light guides than from the standard light guide. CLINICAL SIGNIFICANCE The design of the light guide of a light curing unit affects light dispersion, power density, and ultimately the dentist's ability to properly cure composite. For these reasons, manufacturers should report the power density at the tip of the light guide and 6 mm from the tip of the light guide, since significant differences exist between light guide designs.

High-power-density MHz-switching monolithic DC-DC converter with thin-film inductor

Abstract: In this paper, we report the newly developed DC-DC converter IC termed monolithic DC-DC converter, in which a thin-film inductor and power IC are integrated, and describe the micro DC-DC converter module utilizing this IC. The thin-film inductor used in the monolithic DC-DC converter was fabricated by RF sputtering, photosensitive polyimide lithography and electro-plating onto the power IC. The micro DC-DC converter module using the monolithic DC-DC converter achieved power density of 5.6 W/cm/sup 3/ at output power of 1 W and maximum efficiency of 83.3% at switching frequency of 3 MHz.

Process Characterisation of Pulsed Nd:YAG Laser Seam Welding

Abstract: A wide range of pulsed laser welding parameters was identified. These include average peak power density (APPD), peak power, mean laser power, traverse speed, pulse repetition rate, duty cycle, pulse energy, spot size, and pulse duration. The type of laser beam temporal pulse shape studied was a rectangular power pulse. The effects of pulsed laser welding parameters on heat flow, weld dimension, and weldability are investigated. The study shows that weld quality is principally affected by APPD, mean power, and traverse speed, of which APPD is the most critical process parameter. A processing map containing the APPD effects is constructed as a guide for producing good welds.

Power handling and temperature coefficient studies in FBAR duplexers for the 1900 MHz PCS band

Abstract: Duplexers for 1900 MHz PCS handsets based on FBARS have been realized by micro-machined thin film AlN devices. A major advantage of the FBAR duplexer is a 10-fold reduction in physical volume compared to that of dielectric types. However, since the RF input power to the transmit (Tx) filter remains at levels up to +29 dBm input, the Poynting power density is /spl sim/1 kWatts/cm/sup 2/ with concomitantly large RF strain RF levels. The in-band insertion loss for the entire multi-element Tx ladder filter is/spl sim/3 dB (343 mW dissipated maximum), which results in a volume power dissipation per FBAR/spl sim/1 MWatts/cm/sup 3/. Power densities of this order can lead to 1) frequency shifts due to heating, 2) long term degradation, 3) strain levels approaching the fracture limit of the thin films comprising the FBAR, and 4) thermal destruction of the Tx filter FBARS. We discuss two methods to measure the temperature coefficient of frequency: 1) probing individual FBAR resonators on a hot chuck, or 2) heating packaged duplexers in an oven. The measured resonator frequency temperature coefficient is/spl sim/27 ppm//spl deg/C, while the duplexer Tx response shows a somewhat lower value. Self-heating temperatures can be estimated from this and the observed frequency shift, and were also measured by infrared microscopy. Next, we present preliminary results on the duplexer power handling capabilities, based on a small sample of parts. The Tx devices will withstand up to +36 dBm (4 Watts) input power without destruction. Above this, catastrophic failures can be observed. A scanning electron micrograph example illustrating a catastrophic failure in the duplexer Tx filter will be presented. Finally, we will discuss the effects of high power (+30 to +36 dBm) on duplexer performance. At present we do NOT observe any long term, cumulative effects which could lead to catastrophic failures. Our observations support a model in which device characteristics shift slightly with time.

Estimation of the average power density in the vicinity of cellular base-station collinear array antennas

Abstract: This paper investigates the character of the average power density in the close proximity of base-station antennas, where human exposure to electromagnetic fields radiated from such radiofrequency (RF) sources is the highest. The concept of average power density is used since, in proximity of a large array antenna, the direction of the power flow at a given point is not readily predictable because of the substantially diverging path lengths and direction of propagation of the energy arriving from different array elements. This quantity Is shown to have a marked cylindrical decay near the antennas, which converts to spherical in the far field. On this basis, a set of simple prediction formulas is derived to allow the estimation of the average power density with good precision. The latest IEEE C95.1-1999 Standard for RF safety calls for spatially averaged measurements of incident power density to verify compliance to maximum permissible exposure limits. The advantage of using the concept of average power density and the resulting prediction formulas is that the evaluation of the exposure of humans near cellular base-station antennas becomes extremely simple during surveys when large computerized scanning equipment may not be available.

Neutral bremsstrahlung measurement in an atmospheric-pressure radio frequency discharge

Abstract: Neutral bremsstrahlung emission spectrum is measured in an atmospheric-pressure radio frequency (rf) capacitive discharge for a gas mixture of helium (99.5%) and oxygen (0.5%) using a high resolution triple monochromator between 450 and 1000 nm. Good agreement is obtained for spectral variation and absolute intensity between the observed neutral bremsstrahlung and theoretical emissivity calculated using electron–neutral momentum cross sections. Based on a theoretical fitting, the discharge is characterized by a time averaged electron density of 2.9×1011 cm−3 and an electron temperature of 1.9 eV for an input power density of 28 W/cm3.

High-brightness semiconductor laser sources for materials processing: stacking, beam shaping, and bars

Abstract: A compact, reliable semiconductor laser source for materials processing, medical, and pumping applications is described. This industrial laser source relies on a combination of technologies that have matured in recent years. In particular, effective means of stacking and imaging monolithic semiconductor laser arrays (a.k.a., bars), together with advances in the design and manufacture of the bars, have enabled the production of robust sources at market-competitive costs. Semiconductor lasers are presently the only lasers known that combine an efficiency of about 50% with compact size and high reliability. Currently the maximum demonstrated output power of a 10-mm-wide semiconductor laser bar exceeds the 260 W level when assembled on an actively cooled heat sink. (The rated power is in the range of 50-100 W). Power levels in the kilowatt range can be reached by stacking such devices. The requirements on the stacking technique and the optic assembly to achieve high brightness are discussed. Optics for beam collimation in fast and slow axis are compared. An example for an optical setup to use in materials processing will be shown. Spot sizes as low as 0.4 mm/spl times/1.2 mm at a numerical aperture of 0.3 and output power of 1 kW are demonstrated. This results in a power density of more than 200 kW/cm/sup 2/. A setup for further increase in brightness by wavelength and polarization coupling will be outlined. For incoherent coupling of multiple beams into a single core optical fiber, a sophisticated beam shaping device is needed to homogenize the beam quality of stacked semiconductor lasers. Applications economics dictate that reliable operation is achievable at numerous wavelengths (both for wavelength-specific applications and for brightness scaling through geometric wavelength multiplexing) and at ever higher per bar power levels. New material systems and epitaxial structures continue to be evaluated in this pursuit. Here we include details of designs and performance for devices operating at 808, 830, and 915 nm. These include characteristics of both single-emitter devices and bars.

Progress towards high-power lower hybrid current drive in TORE SUPRA

Abstract: With a new lower hybrid (LH) antenna that will allow us to couple up to 4 MW for 1000 s at a power density of less than 25 MW m-2, and improved diagnosis capabilities provided by the hard x-ray (HXR) fast electron bremsstrahlung tomography, significant progress has been made towards the achievement of fully non-inductive current driven plasmas in TORE SUPRA. Very promising performances have been obtained with the new launcher successfully tested up to 3 MW. At equivalent power levels, coupling properties behave like those of the former antennas (mean reflection coefficient ≤10%), but the heat load on the guard limiter as well as the fast electron acceleration in the near electric field of the grill mouth are considerably reduced. Using the two launchers, a full non-inductive discharge has been sustained without MHD activity for 9.5 s by 4.7 MW of LH power, at a plasma current Ip of 0.8 MA. The mean LH current drive efficiency at zero-loop voltage and for plasma currents lower than 0.8 MA is found to be 0.65×10+19 A W-1 m-2. HXR measurements suggest a significant improvement of the current drive efficiency with Ip, as a consequence of a widening of the quasilinear plateau towards higher velocities, a tendency which is well confirmed experimentally. Profiles of the HXR emission indicate that LH power is absorbed in a very few number of passes at Bt = 3.9 T, the plasma equilibrium playing in this case an important role in the wave dynamics, in agreement with ray-tracing and Fokker-Planck calculations. However, besides toroidal mode coupling, additional mechanisms are likely to contribute to a spectral broadening of the LH wave. When LH power absorption is broad and off-axis, an improved electron core confinement is observed in fully non-inductive discharges. This regime, which is ascribed to some vanishing of the magnetic shear, is found to be transient and usually ends when the safety factor becomes very close to 2, leading to the onset of large MHD activity.

Antireflection coated refractory metal matched emitters for use with GaSb thermophotovoltaic generators

Abstract: GaSb thermophotovoltaic cells can be combined with infrared emitters to produce electric power. In this application, both power density and efficiency are important. High power density requires a practical target emitter temperature of 1600 K. In order to reach this temperature, spectral efficiency becomes extremely important. Radiation with wavelengths greater than 1.8 microns cannot be converted by the GaSb cells; instead, this long wavelength radiation overheats the cells, limiting power density and efficiency. A solution is to use refractory-metal coated emitters, because metals have low emittance at long wavelengths. Further, an antireflection (AR) coating on the metal can enhance the emittance in the cell convertible band. A spectral efficiency of 75% has been demonstrated for an AR coated tungsten emitter and a GaSb cell power density of 1.5 Watts/cm/sup 2/ has been measured with an AR coated tungsten emitter operating at 1555 K.

Physics of the density limit in the W7-AS stellarator

Abstract: Density-limit discharges in the W7-AS stellarator, with constant line-integrated density and a duration of up to 2 s, were studied at three values of the toroidal magnetic field (B = 0.8, 1.25 and 2.5 T). The central factor governing the physics of the density limit in stellarators was demonstrated to be the decreasing net power to the plasma when the centrally peaked radiated power density profile exceeds that of the deposited power density. The process was further accelerated by the peaking of electron density under these conditions. In discharges with B = 2.5 T, simulations of the centrally peaked radiation power density profiles could be shown to be due to peaked impurity density profiles. Laser blow off measurements clearly inferred an inward pinch of the injected aluminium. These discharges had the electron density profile form found in the improved confinement H-NBI mode on W7-AS. The aim of producing steady-state discharges at the highest possible density in stellarators is naturally of special interest for reactor operation. Such a scenario has been best achieved in H-mode discharges, in which ELMs restricted the impurity influx to the plasma and an equilibrium in the plasma parameters with suitably low radiation power levels was possible. A density scan in ECRH discharges highlights the need to control impurity sources and choose electron densities well below the density limit in order that steady-state operation can be attempted in discharges without ELMs. A simple model of bulk radiation predicted that the limiting density should depend on the square root of heating power and this was experimentally confirmed. The magnetic field scaling of the limiting density found experimentally in this simple model will partly depend on the term concerning the radial profile of the impurity density, which in turn is a function of the diffusion coefficient and inward pinch of the impurity ions. Theoretical studies have shown that an assumption about the B dependence of the thermal conductivity leads to density limit scaling laws with an explicit B dependence.

TiOx-modified NiO thin films for H2 gas sensors: effects of TiOx-overlayer sputtering parameters

Abstract: The sensitivity and selectivity of sputtered NiO thin films are found to be promoted by the addition of TiOx-overlayers. The sensing properties are strongly influenced by the sputtering parameters of the TiOx-overlayers. Among all studied films, the modified NiO thin films using TiOx-overlayers deposited in pure Ar gas with a sputtering power density of 1.59 W/cm2 have the best properties for H2 detection. The cross-sensitivity to other gases such as NO2 and NH3 is comparatively small. The response and recovery times of the sensor depend on operating temperature and gas concentrations. The sensor electrical response follows a power law behavior Rg=Ra(PH2)β with the coefficient β≈1.0.

High-power GaN MESFET on sapphire substrate

Abstract: The first power results of GaN MESFET achieved at 2 GHz are presented. A power density of 2.2 W/mm has been obtained with an associated power added efficiency of 27% at V/sub ds/=30 V and V/sub gs/=-2 V. These results represent a significant improvement over similar MESFET's or HFET's grown on GaAs or InP substrates.

Effect of power density and pulse repetition on laser shock peening of Ti-6Al-4V

Abstract: Laser shock peening (LSP) was applied to Ti-6Al-4V (wt. %) simulated airfoil specimens using a Nd:Glass laser. Laser shock peening processing parameters examined in the present study included power density (5.5, 7, and 9 GW/cm2) and number of laser pulses per spot (one and three pulses/spot). The LSP’d Ti-6Al-4V samples were examined using x-ray diffraction techniques to determine the residual stress distribution and percent cold work as a function of depth. It was found that the residual stress state and percent of cold work were relatively independent of LSP power density. However, the number of laser pulses per spot had a significant effect on both residual stress and percent of cold work for a given power density level. In addition, there was a strong correlation between the magnitude of residual compressive stresses generated and the percent cold work measured.

Development of a high power density combustion system for a silicon micro gas turbine engine

Abstract: As part of an effort to develop a microfabricated gas turbine engine capable of providing 10-50 Watts of electrical power in a package less than one cubic centimeter in volume, this thesis presents the design, fabrication, packaging and testing of the first combustion system for a silicon micro heat engine. The design and operation of a microcombustor is fundamentally limited by the chemical reaction times of the fuel, by silicon material and fabrication constraints, and by the inherently non-adiabatic nature of the operating space. This differs from the design of a modern macrocombustion system that is typically driven by emissions, stability, durability and pattern factor requirements. The combustor developed herein is shown to operate at a power density level that is at least an order of magnitude higher than that of any other power-MEMS device (2000 MW/m 3), and establishes the viability of using high power density, silicon-based combustion systems for heat engine applications at the micro-scale. This thesis presents the development of two specific devices the first device is a 3-wafer level microcombustor that established the viability of non-premixed hydrogen-air combustion in a volume as small as 0.066 cm 3, and within the structural constraints of silicon; the second device is known as the engine "static-structure", and integrated the 3-stack microcombustor with the other non-rotating components of the engine. Fabricated by aligned fusion bonding of 6 silicon wafers, the static structure measures 2.1 cm x 2.1 cm x 0.38 cm, and was largely fabricated by deep reactive ion etching through a total thickness of 3,800 pm. Packaged with a set of fuel plenums, pressure ports, fuel injectors, igniters, fluidic interconnects, and compressor and turbine static airfoils, this structure is the first demonstration of the complete hot flow path of a multi-level microengine. The 0.195 cm 3 combustion chamber has been tested for several tens of hours and is shown to sustain stable hydrogen combustion with exit gas temperatures above 1600K and combustor efficiencies as high as 95%. The structure also serves as the first experimental demonstration of hydrocarbon microcombustion with power density levels of 500 MW/m 3 and 140 MW/m 3 for ethylene-air and propane-air combustion, respectively. In addition to the development of the two combustion devices, this thesis also presents simple analytical models to identify and explain the primary drivers of combustion phenomena at the micro-scale. The chemical efficiency of the combustor is shown to have a strong correlation with the Damkohler number in the chamber, and asymptotes to unity for sufficiently large values of Da. The maximum power density of the combustor is also shown to be primarily limited by the structural and fabrication constraints of the material. Overall, this thesis synthesizes experimental and computational results to propose a simple design methodology for microcombustion devices, and to present design recommendations for future microcombustor development. Combined with parallel efforts to develop thin-film igniters and temperature sensors for the engine, it serves as the first experimental demonstration of the design, fabrication, packaging and operation of a silicon-based combustion system for power generation applications at the micro-scale. Thesis Supervisor: Professor Ian A. Waitz Title: Associate Professor of Aeronautics and Astronautics

Coreless printed circuit board (PCB) transformers with high power density and high efficiency

Abstract: The authors report the use of a coreless printed circuit board transformer for power conversion with very high power density and efficiency. A coreless PCB transformer with an outermost radius of /spl sim/1 cm and 19 turns for both the primary and secondary windings can transfer 19 W at an efficiency of 90%, resulting in a record power density of 24 W/cm/sup 2/. The power density and energy efficiency of a coreless PCB transformer are higher than those of core-based microtransformers. Coreless transformers are simpler in structure, easier to implement in silicon wafer and cheaper than core-based planar transformers.

Circuit singulation system and method

Abstract: Electronic circuits such as IC packages, circuit boards, of flex circuits are singulated by laser cutting of adjoining laminated material. The laser beam has a wavelength of less than 400 nm, and either a minimum energy density of 100 J/cm2 or a minimum power density of 1GW/cm2. The method avoids the need for cleaning and intermediate handling, and there is a greatly improved throughput.

Honeycomb electrode fuel cells

Abstract: Solid oxide fuel cells (SOFC) (10) based on mechanically durable honeycomb electrodes (3) supporting thin electrolyte (11) and counter electrode layers in selected honeycomb channels (1, 2) provide dependable operation and high volume power density through extended use cycles.