Solid electrolyte cell

A solid electrolyte cell including a body of solid ionized gas-conductive electrolyte 20 having mutually spaced surfaces 30 and 32 on which is deposited a multiplicity of mutually spaced electrodes 34 and 36, having strips 30 and 32 of bare substances interposed between electrodes, so that currents of ionic gas may be established between the electrodes via the bare strips 30 and 32, whereby electrical resistance for the cells is lowered and the gas conductivity thereof is enhanced.

BACKGROUND OF THE INVENTION 
The invention generally relates to solid electrolyte cells and more 
particularly to an improved solid electrolyte cell having strips of 
platinum defining electrodes extended along opposite side surfaces of the 
cell in mutually spaced parallelism and defining therebetween parallel 
strips of bare substrate surfaces which tend to offer minimal resistance 
to gas flow, whereby the electrical resistance for the cell is lowered and 
the gas conductivity thereof enhanced. 
DESCRIPTION OF THE PRIOR ART 
Use of solid electrolyte cells generally is well known in the separation of 
oxygen from compounds such as carbon dioxide, and the disassociation of 
water into oxygen and hydrogen, as well as in fuel cells for production of 
electricity from a recombination of oxygen and hydrogen. 
As is also well known, the operation of a solid electrolyte cell is based 
on its capabilities for conducting ions when either an electrical 
potential is applied thereacross, or a difference of partial pressures of 
oxygen is caused to exist at the two sides of the solid electrolyte. In 
either case, it is necessary that the opposite surfaces of the solid 
electrolyte be electrically connected so that an ionic current can be 
established between the opposite side surfaces, through the body of solid 
electrolyte. 
The ionic current is, of course, made up of oxygen ions which enter the 
solid electrolyte at the interface of the so-called negative surface and 
exit at the interface of the so-called positive surface, as determined by 
the polarity of the applied voltage. 
The amount of ionic current that can be caused to flow through a solid 
electrolyte with a given total voltage drop is a function of the 
resistance of the electrodes attached to or plated on the opposite 
surfaces of the body of electrolyte. Electrodes for solid electrolyte 
cells of the type aforementioned, conventionally have been made of 
platinum deposited on the surfaces of the body of solid electrolyte as a 
film and then fired. Heretofore, it has been required that the film be 
porous sufficiently as to be gas conductive. To insure an existence of the 
required porosity, the film generally must be applied as a relatively thin 
film. Unfortunately, the electrical resistance of the electrodes thus is 
increased. Conversely, where attempts have been made to increase the mass 
of electrodes, for thereby reducing electrical resistivity, increased 
resistance to gas flow at the surface interfaces is encountered. Hence, 
those engaged in the design of electrolyte cells have for a long while 
been plagued with the attendant design problems arising from these 
competing design parameters. It is therefore, the general purpose of the 
instant invention to provide an improved solid electrolyte cell, having 
enhanced electrical conductivity without an attendant increase in gas-flow 
resistance. 
During the course of a search conducted for the instant invention, the 
patents discovered are listed on the enclosed "List Of Prior Art Cited By 
Applicant". 
Of the patents listed on the enclosed sheet, it is believed that U.S. Pat. 
No. 3,115,702 to Scutt probably is the most pertinent reference discovered 
during the course of the search, aforementioned. This patent discloses an 
electrolytic process in which water is split into hydrogen and oxygen. 
Based upon the realization that the electrode in the process does not have 
to be made entirely of platinum, but that the platinum has to cover only a 
fraction of the total electrode surface, the patentee suggests the use of 
a composite electrode consisting of a refractory base metal, such as 
titanium, niobium or zirconium and an inlaid noble metal such as platinum 
or a platinum based alloy in which the noble metal was added for cathodic 
protection of the anode. It is important to note that the platinum is not 
utilized in forming the electrode but has been added to the base metal 
electrode for protection. Moreover, the size and configuration of the 
platinum strips has no effect on electrolytic operation of the cell and no 
gasses have to cross a solid barrier at the interface. In other words, the 
teachings of this patent suggest a lowering of the total usage of noble 
metal cladding by leaving bare base metal surfaces exposed without an 
attendant deterioration of the base metal. 
OBJECTS AND SUMMARY OF THE INVENTION 
It is an object of the instant invention to provide an improved solid 
electrolyte cell. 
It is another object to provide an improved solid electrolyte cell having 
platinum electrodes deposited on opposite side surfaces of a solid 
electrolyte body in a manner such that enhanced electrical conductivity is 
facilitated without an attendant reduction in the cell's capability of 
accommodating gaseous currents of ions through the body. 
It is another object to provide in a solid electrolyte cell, a body of 
electrolyte material having opposed surfaces, each defining a substrate 
for a plurality of electrodes, said body being characterized by paths for 
ionic currents extended between the opposed surfaces of the body, a 
multiplicity of elongated, mutually spaced electrodes deposited on each of 
said surfaces and having defined therebetween elongated strips of 
substrate surfaces exposed to the ambient environment for the cell, 
whereby an increased electrical flow is accommodated without an increased 
resistance to ionic currents flowing between the electrodes at the 
opposite surfaces of the body. 
These and other objects and advantages are achieved by depositing on the 
opposite surfaces of a body of electrolyte material a plurality of 
mutually spaced bar-shaped electrodes arranged in parallelism for defining 
therebetween strips of substrate exposed to the ambient environment for 
the cell.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now to the drawings, with more particularity, wherein like 
reference characters designate like or corresponding parts throughout the 
several views, there is shown in FIG. 1, an electrolyte cell, generally 
designated 10, embodying the principles of the instant invention. 
It is here important to appreciate that the invention relates primarily to 
the construction of electrodes for the cell 10 and that the cell 10 is 
equally useful in processes in which a separation of oxygen from carbon 
dioxide, and in the disassociation of water into oxygen and hydrogen, or, 
for that matter, in a fuel cell for producing electricity through a 
recombination of oxygen and hydrogen. Therefore, the purpose, particular 
environment, and/or the particular process in which the solid electrolyte 
cell 10 of the instant invention is employed forms no particular part of 
the invention hereinafter more specifically described and claimed. 
As shown in the drawings, however, the solid electrolyte cell 10 is formed 
of an ionized gas-conductive material of a tubular configuration, having 
one end closed and connected at its opposite end through a suitable 
fitting 12 to an oxygen-gas receiver, also not shown. Furthermore, as 
shown, the cell 10 is seated in a clam-shell heater 14, the purpose of 
which is to control the temperature of the cell. Again, since the 
particular environment in which the cell 10 is employed is of no 
particular consequence, a detailed description of the heater 14 is omitted 
in the interest of brevity. 
It therefore suffices to say that the cell 10, as shown, is connected to 
communicate with a source of oxygen-bearing gas, such as CO.sub.2, through 
the fitting 43 and is seated in a conduit 43' mated with a sleeve 16, 
provided for coupling purposes. It is to be understood that the conduit is 
suitable for conducting CO.sub.2 to the external surface of the cell 10 
and is connected in an hermetically sealed relation therewith. A suitable 
union 18, also forming no part of the invention hereinafter described and 
claimed, is provided for connecting the sleeve 16 with the fitting 12. 
Referring now for a moment to FIG. 2, it can be seen that the electrolyte 
cell 10 comprises a body 20 of solid electrolyte having an elongated 
tubular configuration closed at its end, designated 22. The opposite end 
of the body 20 is connected in communication with the fitting 12 through a 
length of tubing 24, formed of a material such as Inconel 600, extended 
through this union 18 and inserted axially into the body 20. The body 20 
is inserted into a length of tubing 26, also formed of Inconel 600, which 
is in turn hermetically sealed, through the use of hermetic seals 28, 
within the sleeve 16. 
As shown in the drawings, the body 20 includes an external surface 30 and 
an internal surface 32, both being of a cylindrical configuration and 
arranged in mutually concentric relation. The material from which the body 
20 is formed comprises a ceramic ionized gas-conducting material, such as, 
for example, eight percent yttria stabilized zirconia, the purpose of 
which is to accommodate an establishment of a plurality of flow paths for 
ionic currents extending between the surfaces 30 and 32. 
Deposited on the external surface 30 of the body 20 is a plurality of 
mutually spaced electrodes 34, of bar-like configurations. These 
electrodes are arranged in parallelism with the longitudinal axis of the 
body 20, and are commonly connected through contact with the length of 
tubing 26. As a practical matter, the tubing 26 functions as a common 
contact or bus bar for the electrodes 34. 
Deposited on the internal surface 32 of the body 20, is a plurality of 
mutually spaced, bar-like electrodes 36. The electrodes resemble the 
electrodes 34 in size and shape and extend in parallelism with the 
longitudinal axis of the body 20. As a practical matter, the electrodes 
34, as well as the electrodes 36, define therebetween bare strips 38 of 
substrate surfaces, whereby the body 20 is exposed at its opposite 
surfaces to ambient environments, both internally and externally. 
The particular manner in which the electrodes 34 and 36 are deposited on 
the surface of the body 20 also forms no part of the instant invention. It 
suffices to say that the number of bare strips 38 of substrate, or body 
surface, for the electrodes 34 and 36, and the width thereof is determined 
by manufacturing limitations. However, the optimum effect is achieved by 
having the largest numbers of electrodes found possible, under practical 
constraints, with the smallest widths found possible. Thus, both the 
electrodes 34 and 36 are arranged to conduct a flow of electron current in 
parallelism with the longitudinal axis of the body. 
As aforementioned, the electrodes 34 are commonly connected with the tubing 
26. The electrodes 36, however, are commonly connected with the length of 
tubing 24. Since the lengths of tubing 24 and 26 are formed of electrical 
conducting material, such as Inconel 600, these lengths of tubing not only 
afford structural strength but additionally serve as bus bars for the 
electrodes extended along the surfaces of the body 20. 
In order to establish an electric field across the cross-sections of the 
body 20, a first lead 40 is connected, by welding, or the like, to the 
length of tubing 26, while a further lead 42 is connected to the length of 
tubing 24, also as by welding or the like. The leads 40 and 42 are, 
preferably, connected to the opposite sides of a voltage source in order 
to establish an electrostatic field across the electrolyte forming the 
body 20. 
OPERATION 
It is believed that in view of the foregoing description, the operation of 
the device will readily be understood, however it will be briefly reviewed 
at this point. 
With the solid electrolyte cell embodying the principles of the instant 
invention assembled in the manner hereinbefore described, it is a simple 
matter to initiate its operation. When connected with a source of gas, 
such as CO.sub.2, through the fitting 43, the CO.sub.2 gas is introduced 
to flow along the exterior surface of the body 20, via the length of 
tubing 16. With an electrostatic field established across the body of 
solid electrolyte, the CO.sub.2 is exposed to the bare strips 30 of 
substrate surfaces, as found to exist between the electrodes 34. These 
electrodes, as a practical matter, function as cathodes. Thus oxygen 
crosses the solid barrier at the interface of ambient environment, causing 
an ionic flow of oxygen to be established along a plurality of paths 
extending from the electrodes 34 to the electrodes 36. The electrodes 36, 
of course, function as anodes. Consequently, the CO.sub.2 is broken down 
as the oxygen ions flow through the body 20 to the internal surface or 
bare strips 38 existing between the electrodes 36. At this surface, the 
ions recombine to form O.sub.2 which is, where so desired, conducted away 
from the solid electrolyte cell 10 via the conduit, connected with the 
sleeve 24. 
In view of the foregoing, it is believed to be readily apparent that the 
solid electrolyte cell which embodies the principles of the instant 
invention provides a practical solution to the problems heretofore 
encountered in attempting to enhance electron flow without an attendant 
reduction in ionic flow through a solid electrolyte body.