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.

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.

Characterization of Multilayer Anodes for SOFC

2002 ◽  
Vol 756 ◽  
Author(s):  
Axel C. Müller ◽  
Albert Krügel ◽  
André Weber ◽  
Ellen Ivers-Tiffée
Keyword(s):  
Single Cells ◽  
Oxidation Stability ◽  
Anode Layer ◽  
Gas Distribution ◽  
Functional Layer ◽  
Fuel Gas ◽  
Term Operation ◽  
Operation Conditions ◽  
Electrochemically Active ◽  
Screen Printed

ABSTRACTSOFC anodes have to combine various tasks. In anode supported single cells a thick anode substrate is used for current collecting and gas distribution whereas a thin functional layer adjacent to the electrolyte is the electrochemically active part of the anode. This functional anode layer is cofired together with the thin film electrolyte to obtain an enhanced interface with low polarisation losses. This multilayer structure was transferred to an electrolyte supported single cell. The electrochemical active Ni/8YSZ anode layer was screen printed onto a 8YSZ electrolyte green tape and subsequently cofired at 1350 °. Mechanical stresses during cofiring due to shrinkage mismatch of anode and electrolyte were avoided by changing the geometry of the anode layer from a continuous layer to a large number of small sized individual areas. Simulations by finite element modeling indicated that a hexagonal pattern similar to honeycombs is preferable. The second layer which adjoins to the fuel gas channels and which is responsible for current collecting and gas distribution was later on screen printed on top and sintered together with the cathode. Single cells with a multilayer anode and different functional layers were electrochemically characterised under realistic operation conditions. The performance and reduction/oxidation stability of this type of anode was investigated. The electrochemically active layer showed only small degradation during redox cycling and long term operation at high fuel utilisation. In contradiction to single layer anodes Nickel agglomeration was not observed in the functional layer.

Stack of Planar Double-Sided Solid Oxide Fuel Cells

2012 ◽  
Vol 2012 (CICMT) ◽  
pp. 000281-000287
Author(s):  
Zbigniew Magonski ◽  
Barbara Dziurdzia ◽  
Henryk Jankowski ◽  
Jan Koprowski ◽  
Teresa Kenig ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Solid Oxide Fuel Cells ◽  
Current Collector ◽  
Functional Layer ◽  
Small Power ◽  
Micro Channels ◽  
Cathode Current ◽  
The Individual ◽  
Base Structure

A new design of a small power SOFC battery is presented. The battery consists of an array of flat double-sided fuel cells assembled with only two screws. Fuel cells are made with the application of commercially available HTCC green tapes. Eight layers of 180μm thick anode tape (YSZ+NiO) constitute the anode base structure of the double-sided fuel cell. Within the anode base structure, the separate areas serve as: the functional anode, the anode current collector, and the support for the anode functional layer. Also a network of fine micro channels is embedded within the anode base structure. The individual double-sided fuel cell is completed by deposition of the following layers, which constitute the electrolyte, the cathode, and the cathode current collector These layers are deposited on both sides of the anode base structure by means of screen-printing. Each double-sided fuel cell is provided with the own separate fuel distributor and combustion product collector. That beneficial feature enables completing the tests, separately for each cell, prior assembly into battery.

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
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