ONEBAT: Micro-Solid Oxide Fuel Cells for Battery Replacement in Portables
Jennifer L. M. Rupp, Ulrich P. Muecke, Daniel Beckel, Anja-Bieberle Hütter
Anna Infortuna and L. J. Gauckler
Nonmetallic Inorganic Materials
ETH Zurich, Switzerland
The Swiss ONEBAT project aims for the fabrication of micro-
solid oxide fuel cells. These are miniaturized solid oxide fuel cells
in which the active fuel cell components (anode, electrolyte and
cathode) exist as thin films forming a free-standing membrane on a
substrate. The total thickness of the fuel cell membrane is less than
2 micrometer in thickness and of 200 micrometer in diameter. Heat
cycling between room temperature and 550°C are possible for such
membranes without rupture or crack development. The future goal
is to integrate these micro-solid oxide fuel cells in a system with
reformer, post-combustor and insulation, and to replace current Li-
ion batteries. Microstructure and electrical conductivity
characteristics of micro-solid oxide fuel cell gadolinia-doped ceria
thin film electrolytes are reported in more details in this study.
Introduction
The spray pyrolysis and pulsed laser deposition techniques offer the advantage to
produce dense SOFC anode, electrolyte and cathode films with typical film thickness of
100 - 1000 nm (1,2). By this technique a micromachinable substrate can be coated with
SOFC components in the form of thin films and afterwards selective etching allows for
the production of SOFC membranes on a chip. The total thickness of such fuel cell
membrane is less than 2 micrometer in thickness and of 200 micrometer in diameter.
Heat cycling between room temperature and 550°C is possible for such membranes
without rupture or crack development. The goal is to integrate these micro-solid oxide
fuel cells in a system with reformer, post-combustor and insulation, and to replace current
Li-ion batteries in portables such laptops, cell phones or other portables. Recently it was
possible to measure, for the first time, open circuit voltage and power characteristics of
such a ONEBAT micro-SOFC at ETH Zurich.
In order to produce such micro-SOFC, it is highly desired to evaluate the properties
of the SOFC components when produced as nanocrystalline thin films. Microstructure
heavily affects the electrical, thermal and thermodynamic properties when SOFC
components, i.e. electrolytes, are produced as thin films.
This manuscript focuses on the impact of microstructure on electrical conductivity
and thermodynamic stability of nanocrystalline Ce
0.8
Gd
0.2
O
1.9-x
(CGO) spray pyrolysis
and pulsed laser deposited thin films. Such films are used as electrolytes for the
ONEBAT micro-SOFC on a chip.
ECS Transactions, 7 (1) 887-890 (2007)
10.1149/1.2729180, ©The Electrochemical Society
887
) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 129.132.210.88 Downloaded on 2016-12-27 to IP