Performance Improvement of (La,Sr)MnO3 and (La,Sr)(Co,Fe)O3-Type Anode-Supported SOFCs

2006 ◽  
Vol 3 (3) ◽  
pp. 263-270 ◽  
Author(s):  
Vincent A. C. Haanappel ◽  
Josef Mertens ◽  
Andreas Mai
Keyword(s):  
Electrochemical Performance ◽  
Performance Improvement ◽  
Sintering Temperature ◽  
High Reliability ◽  
Single Cells ◽  
Tape Casting ◽  
Slip Casting ◽  
Production Costs ◽  
Processing Route ◽  
Functional Layer

Targets in the development of anode-supported or planar solid oxide fuel cells (SOFCs) are low operation temperatures, high durability, high reliability, high power density, and low production costs. During the past ten years steps have already been taken at Forschungszentrum Jülich to lower the operating temperatures while maintaining the power output. This was achieved by optimizing processing and microstructural parameters of the electrodes. This paper presents the latest results concerning performance improvement through variations of the processing route and the microstructure of La0.65Sr0.3MnO3 (LSM) and La0.58Sr0.4Co0.2Fe0.8O3−δ (LSCF)-type SOFCs. In the case of the LSM-type single cells, the following aspects relating to the electrochemical performance were investigated in more detail: (1) production of the anode substrate by tape casting versus warm pressing; (2) deposition of the anode functional layer (AFL) and electrolyte by screen printing versus vacuum slip casting; (3) use of noncalcined and non-ground YSZ for applying the cathode functional layer (CFL); and (4) sintering temperature of the CFL and cathode current collector layer (CCCL). In the case of LSCF-type cells, a systematic approach was initiated for optimizing the Ce0.8Gd0.2O2−δ (CGO) diffusion barrier layer: (1) deposition techniques of the CGO layer and (2) sintering temperature of the screen-printed CGO layer. Results have shown that certain modifications of the processing route led to a slightly lower electrochemical performance, whereas others did not affect the performance at all. Regarding LSCF-type SOFCs, a slight improvement of the performance was achieved by optimizing the sintering temperature of the CGO layer.

The Electrochemical Performance of Anode-Supported SOFCs with LSM-Type Cathodes Produced by Alternative Processing Routes

2005 ◽  
Vol 3 (2) ◽  
pp. 125-130 ◽  
Author(s):  
J. Mertens ◽  
V. A. C. Haanappel ◽  
C. Tropartz ◽  
W. Herzhof ◽  
H. P. Buchkremer
Keyword(s):  
Electrochemical Performance ◽  
Single Cells ◽  
Tape Casting ◽  
Current Collector ◽  
Functional Layer ◽  
Fuel Gas ◽  
Production Route ◽  
Alternative Processing ◽  
Cathode Current ◽  
Alternative Processing Routes

The electrochemical performance of La0.65Sr0.3MnO3-type (LSM) anode-supported single cells, produced by alternative production processes, has been investigated at intermediate temperatures. In particular, three different variations of the production route were investigated in more detail: (1) the use of nonground LSM powder for the cathode current collector layer, (2) the use of noncalcined and nonground YSZ powder for the cathode functional layer, and (3) the use of tape casting versus warm pressing as the production process for anode substrates. Results from electrochemical measurements performed between 700 and 900°C with H2 (3vol%H2O) as fuel gas and air as the oxidant showed that performance increased with increasing grain size of the outer cathode current collector layer: the highest performance was achieved with nonground LSM powder. Furthermore, performance was not adversely influenced by the use of noncalcined and nonground YSZ for the cathode functional layer. Also the use of anode substrates with a thickness of about 0.7mm and produced by tape casting, instead of those with a thickness of about 1.5mm and applied by warm pressing, did not detrimentally affect the electrochemical performance of this type of SOFC.

Sintering Behavior of (La,Sr)MnO3 Type Cathodes for Planar Anode-Supported SOFCs

2006 ◽  
Vol 3 (4) ◽  
pp. 415-421 ◽  
Author(s):  
Josef Mertens ◽  
Vincent A. C. Haanappel ◽  
Christian Wedershoven ◽  
Hans-Peter Buchkremer
Keyword(s):  
Electrochemical Performance ◽  
Sintering Temperature ◽  
Single Cells ◽  
Current Collector ◽  
Extensive Study ◽  
Sintering Behavior ◽  
Functional Layer ◽  
Power Sources ◽  
Microstructural Parameters ◽  
Cathode Current

One of the main targets in the development of anode-supported solid oxide fuel cell (SOFCs) is to improve the electrochemical performance. This can be achieved by optimizing processing and microstructural parameters of the SOFCs. Variations of the thickness of the cathode functional layer and the cathode current collector layer, the grain size of the powders used for applying these layers, and the sintering temperature, can influence the electrochemical performance as such that lower operation temperatures become possible without detrimentally affecting the power output to a great extent. In this study the effect of variations of the sintering temperature of the cathode on (1) the microstructure, (2) the gas diffusivity and permeability in the cathode, and (3) electrochemical performance of FZJ-type anode-supported single cells, was investigated. The FZ-Jülich cell design is based on anode-supported type cells, which are characterized by a relatively thick anode (thickness: 1.0-1.5mm) consisting of a NiO/8YSZ cermet, a thin 8YSZ electrolyte, and a bi-layered cathode. The cathode distinguished two separated layers: first a cathode functional layer consisting of La0.65Sr0.3MnO3(LSM)∕Y2O3-stabilized ZrO2 (8YSZ) and a cathode current collector layer of pure La0.65Sr0.3MnO3 (LSM). This study can be considered as a follow-up of that (Journal of Power Sources 141 (2005) 216–226) describing the improvement of the cell performance by a systematic variation of the microstructure. The experiments described in this paper and the corresponding results are part of a more extensive study to investigate in more detail the effect of the sintering temperature on the electrochemical performance of LSM-type SOFCs. Since research is still going on, conclusions, drawn in this contribution, are yet not definitive.

Residual stresses in Al2O3/Y-TZP Ceramic Laminates Fabricated by Tape and Slip Casting

2008 ◽  
Vol 571-572 ◽  
pp. 327-332 ◽  
Author(s):  
Jesus Ruiz-Hervias ◽  
Giovanni Bruno ◽  
Jonas Gurauskis ◽  
A.J. Sanchez-Herencia ◽  
C. Baudin
Keyword(s):  
Residual Stress ◽  
Neutron Diffraction ◽  
Residual Stresses ◽  
Volume Fraction ◽  
Tape Casting ◽  
Slip Casting ◽  
Ceramic Composites ◽  
Processing Route ◽  
Alumina Matrix ◽  
Stress Profiles

Residual stress profiles were measured by neutron diffraction in Al2O3/Y-TZP ceramic composites containing 5 and 40 vol.% Y-TZP fabricated by conventional slip casting and by a novel tape casting route. Residual stresses in the zirconia are tensile and increase as its volume fraction decreases. For the alumina matrix, residual stress is compressive and increases with the zirconia volume fraction. In the composite with 5 vol.% zirconia, the processing route does not have an influence on residual stresses. However, in the composite with 40 vol.% zirconia, residual stresses are different in the samples obtained by both processing routes.

Effect of Sintering Temperature on Properties of Setiu Clay Sediments

2020 ◽  
Vol 1010 ◽  
pp. 206-210
Author(s):  
Mohd Al Amin Muhamad Nor ◽  
Noor Asliza Ismail Adnen ◽  
Mohamad Zaky Noh ◽  
A.R.M. Warikh ◽  
Julie Juliewatty Mohamed
Keyword(s):  
Sintering Temperature ◽  
Slip Casting ◽  
Casting Process ◽  
Production Costs ◽  
Ceramic Samples ◽  
Before And After ◽  
Different Temperatures ◽  
Clay Sediment ◽  
Quality Of Products ◽  
Increasing Temperature

The effect of sintering temperature on physical properties of Setiu clay sediment was studied. The ceramic samples were prepared via slip casting method, and sintered at different temperatures ranging from 900 to 1100°C, with 2 hours soaking time. Morphologies of ceramic samples were characterized using Tabletop Microscope. Shrinkage was determined from measurement of samples before and after sintering process. A good ceramic sample without warping or cracks obtained after casting process and after sintered at different temperatures. The results show that sintering temperatures greatly influence morphology of samples. As sintering temperature increased the grain boundaries between particles become smoother and compacted while pores shrunk due to the densification behavior. A considerable increased in shrinkage from 5 to 20% were observed with increasing temperature from 900 to 1100°C. As conclusion, Setiu clay sediment are suitable for production ceramic products and 1000°C can be consider the best sintering temperature in terms of quality of products and production costs.

CONVEYOR MODEL AND IMPLEMENTATION OF THE REAL NUMBERS ADDER ON FPGA

2020 ◽  
Vol 33 (109) ◽  
pp. 21-31
Author(s):  
І. Ya. Zeleneva ◽  
Т. V. Golub ◽  
T. S. Diachuk ◽  
А. Ye. Didenko
Keyword(s):  
Performance Improvement ◽  
Experimental Studies ◽  
Production Costs ◽  
Floating Point ◽  
Computing Device ◽  
Quartus Ii ◽  
Functional Blocks ◽  
Mental Testing ◽  
Processor Cores ◽  
Floating Point Numbers

The purpose of these studies is to develop an effective structure and internal functional blocks of a digital computing device – an adder, that performs addition and subtraction operations on floating- point numbers presented in IEEE Std 754TM-2008 format. To improve the characteristics of the adder, the circuit uses conveying, that is, division into levels, each of which performs a specific action on numbers. This allows you to perform addition / subtraction operations on several numbers at the same time, which increas- es the performance of calculations, and also makes the adder suitable for use in modern synchronous cir- cuits. Each block of the conveyor structure of the adder on FPGA is synthesized as a separate project of a digital functional unit, and thus, the overall task is divided into separate subtasks, which facilitates experi- mental testing and phased debugging of the entire device. Experimental studies were performed using EDA Quartus II. The developed circuit was modeled on FPGAs of the Stratix III and Cyclone III family. An ana- logue of the developed circuit was a functionally similar device from Altera. A comparative analysis is made and reasoned conclusions are drawn that the performance improvement is achieved due to the conveyor structure of the adder. Implementation of arithmetic over the floating-point numbers on programmable logic integrated cir- cuits, in particular on FPGA, has such advantages as flexibility of use and low production costs, and also provides the opportunity to solve problems for which there are no ready-made solutions in the form of stand- ard devices presented on the market. The developed adder has a wide scope, since most modern computing devices need to process floating-point numbers. The proposed conveyor model of the adder is quite simple to implement on the FPGA and can be an alternative to using built-in multipliers and processor cores in cases where the complex functionality of these devices is redundant for a specific task.

Phase Inversion Tape Casting and Electrochemical Performance of Solid Oxide Fuel Cell Anode

2015 ◽  
Vol 30 (12) ◽  
pp. 1291
Author(s):  
ZHANG Yu-Yue ◽  
LIN Jie ◽  
MIAO Guo-Shuan ◽  
GAO Jian-Feng ◽  
CHEN Chu-Sheng ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Electrochemical Performance ◽  
Solid Oxide Fuel Cell ◽  
Phase Inversion ◽  
Tape Casting ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Cell Anode ◽  
Fuel Cell Anode

scholarly journals Optimization of Sintering Process of Alumina Ceramics Using Response Surface Methodology

2021 ◽  
Vol 13 (12) ◽  
pp. 6739
Author(s):  
Darko Landek ◽  
Lidija Ćurković ◽  
Ivana Gabelica ◽  
Mihone Kerolli Mustafa ◽  
Irena Žmak
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Heating Rate ◽  
Sintering Temperature ◽  
Nonlinear Models ◽  
Slip Casting ◽  
Holding Time ◽  
Alumina Ceramics ◽  
Aqueous Suspensions ◽  
Temperature Heating

In this work, alumina (Al2O3) ceramics were prepared using an environmentally friendly slip casting method. To this end, highly concentrated (70 wt.%) aqueous suspensions of alumina (Al2O3) were prepared with different amounts of the ammonium salt of a polycarboxylic acid, Dolapix CE 64, as an electrosteric dispersant. The stability of highly concentrated Al2O3 aqueous suspensions was monitored by viscosity measurements. Green bodies (ceramics before sintering) were obtained by pouring the stable Al2O3 aqueous suspensions into dry porous plaster molds. The obtained Al2O3 ceramic green bodies were sintered in the electric furnace. Analysis of the effect of three sintering parameters (sintering temperature, heating rate and holding time) on the density of alumina ceramics was performed using the response surface methodology (RSM), based on experimental data obtained according to Box–Behnken experimental design, using the software Design-Expert. From the statistical analysis, linear and nonlinear models with added first-order interaction were developed for prediction and optimization of density-dependent variables: sintering temperature, heating rate and holding time.

Slip Casting Used as a Forming Technique for Hydroxyapatite Processing

2016 ◽  
Vol 720 ◽  
pp. 219-222 ◽  
Author(s):  
Rubens Lincoln Santana Blazutti Marçal ◽  
Daniel Navarro da Rocha ◽  
Marcelo Henrique Prado da Silva
Keyword(s):  
Slip Casting ◽  
Ceramic Materials ◽  
Processing Route ◽  
Ceramic Suspension ◽  
Polyethylene Glycol 400 ◽  
Density Measurements ◽  
Hydroxyapatite Powder ◽  
Heat Treated ◽  
Thermal Phase ◽  
Before And After

Ceramic materials have particular properties when compared to other classes of materials, exhibiting poor ductility as an example. Slip casting is a widely used ceramic forming technique, and already established in the literature and in the ceramic industry. This study aims to present slip casting as a processing route for producing hydroxyapatite (HA) struts, and show the thermal phase stability. The ceramic suspension was produced and stabilized with hydroxyapatite powder, deionized water and polyethylene glycol 400. The slip was poured into gypsum mold. The green bodies were heat treated at 900 and 1100°C. Hydroxyapatite was the only phase present in all samples, before and after heat treatments. Density measurements showed that the densification was higher for the ceramic bodies sintered at 1100°C, when compared to the ones calcined at 900°C.

Synthesis of High-Performance Hard Carbon from Waste Coffee Ground as Sodium Ion Battery Anode Material: A Review

2021 ◽  
Vol 1044 ◽  
pp. 25-39
Author(s):  
Hafid Khusyaeri ◽  
Dewi Pratiwi ◽  
Haris Ade Kurniawan ◽  
Anisa Raditya Nurohmah ◽  
Cornelius Satria Yudha ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Electrode Material ◽  
High Performance ◽  
Production Costs ◽  
Sodium Ion ◽  
Carbon Anode ◽  
Sodium Ion Battery ◽  
Sodium Ion Batteries ◽  
Hard Carbon ◽  
Coffee Grounds

The battery is a storage medium for electrical energy for electronic devices developed effectively and efficiently. Sodium ion battery provide large-scale energy storage systems attributed to the natural existence of the sodium element on earth. The relatively inexpensive production costs and abundant sodium resources in nature make sodium ion batteries attractive to research. Currently, sodium ion batteries electrochemical performance is still less than lithium-ion batteries. The electrochemical performance of a sodium ion battery depends on the type of electrode material used in the manufacture of the batteries.. The main problem is to find a suitable electrode material with a high specific capacity and is stable. It is a struggle to increase the performance of sodium ion batteries. This literature study studied how to prepare high-performance sodium battery anodes through salt doping. The doping method is chosen to increase conductivity and electron transfer. Besides, this method still takes into account the factors of production costs and safety. The abundant coffee waste biomass in Indonesia was chosen as a precursor to preparing a sodium ion battery hard carbon anode to overcome environmental problems and increase the economic value of coffee grounds waste. Utilization of coffee grounds waste as hard carbon is an innovative solution to the accumulation of biomass waste and supports environmentally friendly renewable energy sources in Indonesia.

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