FIELD OF INVENTION
The present invention relates to devices having at least one brittle component
such as electrochemical devices, including, without limitation, assembly of a
single or plurality of fuel cell component, dense electrolyte, solid membrane, gas
separation element, gas filtration element, catalyst, catalyst substrate, etc.,
made out of ceramic, metallic, polymer or a combination of such materials in the
form of solid, porous, sheet, flake, film, honeycomb, foam, felt, mat or a
combination of such forms and to be operated at ambient temperature or at any
elevated temperature depending on the use and situation. In particular the
invention relates to stress reducing mounting and methods of forming such
mounting useful for making assembly, while making above described devices
having at least one brittle or relatively less flexible component as its part.
BACKGROUND OF THE INVENTION
The power generating component of fuel cell system is commonly called "stack"
which is an electrochemical device. The stack comprises:
(a) one or more cell, the key transactional center of the fuel cell device where
chemical energy is converted into electricity. Generally, a solid oxide fuel
cell (SOFC) includes an air electrode (cathode), a fuel electrode (anode),
and a solid oxide electrolyte provided between these two electrodes and

all these layers are fused together into a single sheet sometimes referred
as electrolyte sheet. Some SOFC design may also include additional
functional layers.
(b) fluid passages for distributing fuel and oxidant,
(c) current collectors for conducting current to and from the cell,
(d) seal gasket either rigid glass, compressive or composite type, and
(e) structural hardware for providing any necessary compression for seals
and or electrical contacts.
Devices such as solid oxide fuel cells (SOFCs) have huge potential for use in
power generation with one of the highest efficiency and least environmental
impact (air and noise) among the technologies available today. This reportedly
ultimate dream of advanced power generation technology is still far behind in
commercial acceptance because of its poor durability and failure of the device
assembly during use arising from the shorten useful life of the ceramic parts due
to thermo-mechanical stresses generated out of existing assembly methods.
Several issues basically originating from the existing assembly methods known
today for SOFC stack are drop of power with use, instability, durability, drop of
efficiency etc. These issues make SOFC technology very complicated to built,
difficult to stabilize and expensive to operate. Because of this reason the cost
and reliability of the present SOFC technology is far discouraging when compared
with existing power generation technologies.

Both rigid and compressive seals are being developed for SOFCs. The most
common approach is to use rigid glass or glass-ceramic seals, the properties of
which can be tailored specifically for use in SOFCs through variation of the glass
composition. However, these rigid seals are inherently brittle, permanently seal
the parts preventing stress relaxation, have more stringent requirements for
adherence and prone to cracking particularly during heating/cooling due to
differences in thermal properties. Thus thermal cycling poses a challenge to the
rigid glass seals.
A major advantage of compressive seals is that the seals are not rigidly fixed to
the other SOFC components, so an exact match of thermal expansion property is
not very essential. Thus poses less damage to the cells while heating/cooling,
thermal cycling and routine operation. The compressive seals promise better and
inexpensive seals than rigid seals.
However the use of compressive seal is limited because as per current practice of
assembly the brittle ceramic cells limit the application of compressive force to
avoid failure. The reason why most of the time compressive seal fails to provide
adequate seal in a device assembly is because the assembly methods known and
in practice today prevents the application of the required compressive force
which is necessary for effective sealing.

Therefore there is a need to provide a new assembly method by which it is
possible to apply freely the required compressive load necessary for effective
sealing without any limitation. It is also require to reduce stresses on brittle
components by new and improved assembly method for devices.
PRIOR ART
US patent No. 4,743,519 for a fuel cell of phosphoric acid type, describes an
electrode substrate provided with peripheral sealers for a fuel cell, comprising
two porous and carbonaceous electrodes respectively provided with flow
channels of the reactant gas. The device assembly described in this patent has
all flexible materials relative to each other as its assembly parts; hence not much
benefit would be derived by reducing the stress in the mounting in its present
form. However the power density of such assembly of cells is much inferior
compared to the ceramic based dense electrolyte fuel cells.
US patent No. 4,476,196 describes a solid oxide fuel cell assembly having
ceramic based solid electrolyte, monolithic cross flow core and ceramic paste
based seal for isolating the fuel and oxidant gas flows. According to the claim of
the patent the said cathode is lanthanum manganite (LaMnO3); said anode is
cobalt yttria-stabilized zirconia cermet or mixture (Co+ZrO2+Y2O3); said
electrolyte is yttria-stabilized zirconia (ZrO2+Y2O3); and said interconnect is
lanthanum chromite (LaCrO3). In spite of its other advantages such as superior

power density, the assembly described in this patent is not at all durable and
inherently prone to failure due to the way it mounted its brittle components
together with the sealant in the assembly.
US patent No. 5,942,348 describes a high-temperature fuel cell having a ceramic
based solid electrolyte between metal plates. The surfaces of the metal plates
are at least partly coated with stabilized zirconium oxide or a similar firmly
adhering gas-tight ceramic. The coating reduces the gap between the plates at
the edge of the fuel cell and makes it possible to fill the reduced gap with a glass
solder green foil or a similar solder material which forms a gas-tight lateral seal
for the fuel cell during the assembly of the fuel cell. However the assembly
depends on the rigid seal between the brittle electrolyte and dissimilar metal
having different thermal expansion properties makes the cell assembly
susceptible to thermo-mechanical damages during heating/cooling and less
durable during use.
US patent application publication no. 2003/0203267 dated October 30, 2003
shows additional compliant interlayers (glass or metal) to mica based seals the
leak rates can be reduced substantially. Further US patent application publication
No. US 2004/0048137 Al dated March 11, 2004 described a seal composed of
compliant interlayers (glass or metal) and a sealing (gasket) member layer
composed of mica that is infiltrated with a glass forming material, which more
effectively reduces leaks within the seal. However the full potential of these seals

developed could not be derived in these disclosures and generally in the industry
because of the brittle ceramic sheet component of the cell is mounted by
sandwiching it with the seal and directly applying the sealing compressive force
on the brittle ceramic component for transmitting the force to the seal. This
method of mounting obviously limits the applicable compressive force to avoid
the brittle fracture of the ceramic sheet. This method seriously curtails the
capacity of the compressive seals or any composite seal described above and
hence gas leak is reduced but can not be avoided as it is clear from the
published patent applications.
US patent application publication No. 2006/0239765 Al dated Oct 26, 2006
discloses a joint with flexible metallic gasket which intends to absorb and
dissipate the differences in the expansion and contraction of the ceramic and
metal parts of the assembly during use. The flexible gasket is attached to the
metal part on one side and hematically bonded to the ceramic part on the other
side. The said joint is configured to flex in response to changes in the size of the
metal part and the ceramic part brought about by temperature changes while
maintaining a hermatic seal between the said flexible gasket and the said
ceramic part of the assembly. However there are practical difficulties to maintain
the hermaticity of the metallic flexible gasket and the ceramic part particularly in
dynamic conditions during use. It will be very expensive to make such hermatic
joint between metal and ceramic particularly at elevated temperature which
requires huge resources. For example to realize such an high end metal-to-

ceramic joint, an expensive metal alloys with its tailored thermal expansion
matching with the ceramic and also an expensive high-temperature compatible
brazing materials are required. Therefore huge resources are required to build
industrial scale devices where a large numbers of ceramic parts in a compact
volume are required to be assembled.
US patent application publication No. US 2007/0072043 Al dated March 29, 2007
described a stress reducing mounting for a ceramic sheet assembly in a SOFC. In
this disclosure the reduction of stress for the brittle ceramic electrolyte sheet,
which is the weakest part is attempted by providing convex curved surface on
the inner edge of the frame or manifold that makes area contact with the
peripheral portion of the electrolyte sheet during use. It is claimed that such
stress reducing mounting reduces cracking in the electrolyte sheet. However
even this said improvement does not provide any solution to the shortcomings of
the basic assembly methods by which the brittle ceramic sheet is equally
subjected to sealing forces due for the rigid or compressive seal in use. Further
improvements are also attempted by providing a layer of compliant material
between said convex curved surface and electrolyte sheet, thickening of part of
the said electrolyte sheet or providing ribs/corrugations on it and also additional
disclosures stated in the US patent application publication No. US 2008/0166616
Al dated July 10, 2008.

Unfortunately all these attempts are aiming for marginal improvements within
the domain of the present practice of assembly which itself is having serious
limitation by preventing application of the needed sealing force beyond the
capacity of the weak ceramic electrolyte sheet.
SUMMARY OF THE INVENTION
It is clear from the prior art and current industrial practice that several failure of
brittle part of the assembly of device, typically fracturing of ceramic electrolyte in
SOFC assembly during use is the main shortcoming of the current practice which
need to be avoided to improve the device more specifically the life and durability
of the SOFC stack assembly to a commercially acceptable level. Further it is
required to facilitate providing of adequate load to the seal assembly for proper
functioning of the seals without damaging the brittle components of the
assembly. Therefore the object of this invention is to devise a stress reducing
mounting assembly and methods of forming such assembly which adequately
seal the required parts of the device but does not transmit the same stress to the
relatively brittle part of the assembly unlike as presently practiced in the art.
According to one aspect of the invention, a novel concept is developed by
visualizing the assembly of a device as an amalgamation of two zones; zone 'A'
and zone 'B'. Within zone 'A' of the assembly the compressible sheet member
which may sometimes act as extension of the seal member is in area contact

with the brittle component of the assembly. Whereas within zone 'B' the seal
member and/or sealing gasket are in area contact with the sealing mechanism of
the assembly without any brittle component or brittle member of the device
available in this zone. In the assembly of the device, the zone 'A' is loaded with
lower compressive force well within the safe loading allowed as per the capability
of the brittle component. The load applied within zone 'A' of the assembly is
comparable to the load normally being applied for seal member of device
assembly in present industry practice as known in the art. Therefore the
compressible sheet member which may sometimes be the seal member which is
in area contact with the brittle component of the assembly could as well impart
gas sealing between gas flow field and the brittle component of the assembly.
However mild gas permeability is a possibility for such sealing in zone 'A'.
Whereas zone 'B' of the seal member will be loaded with much higher load which
is required to seal adequately the device for complete gas tightness. The said
configuration is disclosed first time in this invention which results into a mildly
gas permeable seal portion at designated zone 'A' of the assembly, and another
gas impermeable seal portion at designated zone 'B' of the same assembly.
Mildly gas permeable section of the assembly not rendering the local sealing
arrangement of the said section gas impermeable, but reduces the gas leakage
substantially. The slightly leaked gas being accumulated in tiny gas tight
enclosed chamber surrounding the mildly gas permeable section of the assembly,
which is either continuously or periodically recycled and/or purged out, and/or

used for heating incoming gas, and/or for any other useful purposes. Such tiny
gas tight enclosed chamber formed around each cell may be interconnected with
all other similar chambers of a multi-cell stack and periodic purging and/or
recycling of the slightly leaked gas can be automatically programmed.
In another aspect of the invention the mildly gas permeable section of the
assembly not rendering the local sealing arrangement of the said section gas
impermeable on its own, but being subjected to external gas supply to the tiny
gas tight enclosed chamber which surrounds it. As a result the mildly gas
permeable section of the seal member experiences a slightly positive gas
pressure surrounding it within the tiny gas tight enclosed chamber which also
reduces drastically the mild leakage of gas to an acceptable level. Such tiny gas
tight enclosed chamber formed around each cell may be interconnected with all
other similar chambers of a multi-cell stack and commonly connected to a gas
supply for providing a slightly positive gas pressure.
Thus the invention addresses two contradicting requirements such as high
mounting force requirement for the sealing part and low mounting force
requirement for the brittle component part, and provides solution for both the
requirement by special mounting assembly which redistribute the applied force
facilitating adequate seal and concurrently reducing stress on brittle ceramic part
leading to improved life and durability of the fuel cell assembly. This invention
can also be used for any devices where one or more parts are made out of brittle

materials and mechanical loads need to be applied on the assembly for sealing
during use.
Yet another aspect of the invention by which the seal member, the brittle
member and one or more stiff member, if any in the assembly are mounted by
stacking on each other to make the assembly of the device. The novel
configuration disclosed in this assembly facilitates isolation of the brittle member
from directly clamping with other relatively flexible members and subjected to
differential compressive load.
Yet another aspect of the invention by which the brittle member and other
relatively flexible members of the assembly are mounted by stacking on each
other layer by layer to make the assembly of the device. The novelty of the
configuration incorporated in this assembly is the isolation of the pressure
application area for the brittle member which is independent from pressure
application area for the other relatively flexible members. Whereas the
assembled stack still behaves like a monolith wherein the brittle member is well
supported by flexible members on both side with light compressive load. At the
same time the whole assembly is subjected to differential compressive load and
high compressive load acting on the flexible members keep the whole assembly
stable and gas impermeable. As a result of this inventive method of assembly of
members of the device, each brittle member of the device experiences a floating
like freedom while in use under dynamics of fluctuating temperature and

fluctuating dimensional changes due to differential thermal expansions within
and between members of the assembly.
This unique configuration arising out of the novel method of assembly first ever
disclosed in this patent application substantially reduces the stress particularly on
each of the brittle member of the assembly of device. As a result the likelihood of
failure of the weak region of the device substantially reduces.
The invention of the unique method disclosed makes it possible to partially
isolate a member which is either weak or under the influence of warping or
complex elastic forces within itself and allow such delicate members to float i.e.
have freedom to flex on the support of flexible members under a light
compressive load. During use, in this way the weak and brittle member reduces
its stresses within the limit of the low compressive force such as described earlier
within the zone 'A' of the seal member. This unique condition created by this
invention is going to affect significantly for the success of such devices in
practice, since the warping of planar SOFC single cell is a very common problem
known to the people skilled in the art. The complex elastic behavior of the fuel
cell material also arises due to lamination of different materials, asymmetry,
inhomogeneities, microcracks, pores, grain boundaries, oxidation, reduction and
growth during use.

Further objects and advantages of this invention will be more apparent from the
ensuing description.
At the outset of the description which follows, it is to be understood that the
ensuing description only illustrates a particular form of this invention. However,
such a particular form is only intended as an exemplary embodiment and
teaching of the invention and not intended to be taken restrictively.
OBJECTS OF THE INVENTION
It is therefore an object of the invention to propose a stress reducing mounting
in assembly of brittle component for making devices which is capable of
eliminating the disadvantages of prior arts.
Another object of the invention is to propose a stress reducing mounting in
assembly of brittle component for making devices which adequately seal the
required parts of the device without transmitting the same stress to the relatively
brittle part of the assembly.
A still another object of the invention is to propose a stress reducing mounting in
assembly of brittle component for making devices which results into a mildly gas
permeable seal portion at designated zone say 'A' of the assembly and another
gas impermeable seal portion at designated zone say 'B' of the same assembly.

A further object of the invention is to propose a stress reducing mounting in
assembly of brittle component for making devices which simultaneously meet the
requirement of high mounting force for the sealing part and low mounting force
for the brittle component part.
A still further object of the invention is to, propose a stress reducing mounting in
assembly of brittle component for making devices which is capable of isolating
the pressure application area for the brittle material during assembly of the
device from that of flexible members.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Fig.l - shows a schematic perspective cross-section of a representative portion
of multi-cell stack assembly showing embodiments of the invented assembly
method for planar SOFC application.
Fig.2 - shows an isometric view of a part of the stack representing embodiments
of the invented assembly method illustrating gas flow grooves and their
connecting channels.
Fig.3 - shows a schematic perspective cross-section of a representative portion
of multi-cell stack assembly showing another embodiment of the invented
assembly method for planar SOFC application.

Fig.4 - shows an isometric view of a part of the stack representing another
embodiment of the invented assembly method illustrating gas flow grooves and
their connecting channels.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE
INVENTION
Referring to Figure 1, which illustrates a cross-section of a representative portion
of a multi-cell stack assembly showing a cell 4, compressible sheet 6, sturdy
sheet 5, sealing gasket 7, sealing gasket 8, support washer 9. The cell 4 broadly
comprises of a cathode 1, electrolyte 2 and an anode 3. The assembly of the
device as shown in Figure 1 is under the compressive load while in use. The cell
4 which is the brittle and most delicate member of the assembly is held between
two compressible sheets 6, one from bottom and another from top. The other
side of the compressible sheet 6 is also in area contact with sturdy sheet 5. The
assembly is held in position by a compressive loading mechanism within zone 'B'
involving several sealing gasket 7, sealing gasket 8, support washer 9 and
several end portions of 5 and 6. Whereas within zone W, members 5, 6 and
extended portion of 8 are encrusted on each other and a defined light
compressive load will be acting on it which will be decided by the material
properties of 5 and 6 in correlation with the compressive force loaded by the
mechanism fixed over the zone 'B'.

According to the first embodiment of the invention the brittle and most delicate
member of the assembly, cell 4 is mounted in such a way that it is outside the
high compressive force zone of the loading mechanism. The electrochemical cell
is a planar solid oxide fuel cell (SOFC) includes an air electrode (cathode) 1, a
fuel electrode (anode) 3 and a solid oxide electrolyte 2 provided between these
two electrodes and all these three layers are fused together into a single sheet.
In this version of the embodiment we have used a SOFC cell which is a sintered
double layer of porous NiO/YSZ coated with a dense 8YSZ (8 mol% Y2O3 doped
ZrO2) electrolyte layer and a dense YDC (Yttria doped Ceria) layer with a LSCF
(Lanthanum Strontium Cobalt Ferrite Oxide) cathode layer on it. Such SOFCs are
freely available in commercial market for various sizes. This cell is operated
between 600 to 850°C during operation. A mixer of Hydrogen gas mixed with
Nitrogen and moisture is supplied to the stack along the plane F shown in the
figure as fuel gas for flowing over anode 3. Air is supplied as oxidant gas along
the plane 0 so that it flows over cathode 1. Nitrogen gas is used for purging
along the plane P to the tiny chamber around the cell where mildly leaked gas, if
any being accumulated. The compressible sheet 6 is constructed using high
temperature felt made out of Alumina-Zirconia fiber available commercial market.
Sealing gasket 7 and 8 are also constructed using high temperature felt. Support
washer 9 is fabricated from Crofer 22 metal, however it can be manufactured
from any high temperature steel such as SS316, SS310 etc. As indicated in
Figure l,within zone 'A', the member 6 on both sides of cell 4 are less

compressed relative to the peripheral portions of the 6 which are within zone 'B'
and clamped under the high compression load mechanism.
Gas flow grooves are shown in Figure 2 using an isometric view of a part of the
stack. Gas flow grooves 60 are cut in the central part of 6, which are connected
to the Fuel and oxidant ducts running vertically on the outer side of the assembly
outside the high compression zone 'B'. Surface grooves 60 cut at the central
portion of the compressible sheet 6 facing the cathode 1 are connected with
'oxidant in' 0 and 'oxidant out' 0 ducts through lateral connecting channels 61
and 61A, respectively. Surface grooves 60 cut at the central portion of the
compressible sheet 6 facing the anode 3 are connected with 'fuel in' F and 'fuel
out' F ducts through lateral connecting channels 63 and 63A, respectively. Lateral
connecting channels 61, 61A, 62, 63 and 63A are engraved on any one sheet of
5,6,7,8 and 9 or on both adjacent sheets simultaneously. One type of gas flow
grooves 60 is shown in this Figure 2, however many other variations of the gas
flow grooves are possible such as circular or curvy along length, circular or oval
in cross-section, variable cross-section along the length and many others
depending on the specific application. The gas flow grooves 60 for fuel and
oxidant can be different and gas flow for fuel and oxidant can be same side flow,
counter flow or cross flow. The area marked on the stack in Figure 2 as Q-R-S-T
is the plan view of the approximate position of the active area and equal to the
active area of the cell. The central portions of both the compressible sheet 6
marked Q-R-S-T are in area contact with either cathode or anode and also lying

within light compression zone 'A' provides sealing for the gas flowing through the
grooves cut on central portion of 6. The grooves 60, 61, 61A, 62, 63 and 63A are
cut or engraved by using commercially available LASER cutting and engraving
machine.
The sturdy sheet 5 is made out of metal or non-metals. In this version of the
embodiment we have used Crofer 22, which is commercially available metal alloy
for use at elevated temperatures. Interconnection for connecting anode 3 of one
cell to cathode 1 of the adjacent cell through the Crofer 22 metal sheet 5 is done
using Platinum mesh placed along the grooves 60 and pressed between the
surfaces of 4 and 5 without causing significant resistance to the gas flow in the
grooves. When pressed between the surfaces of 4 and 5 inside the gas grooves
60 the platinum mesh collect the current generated in 4 and carry it to Crofer 22
metal sheet 5. Similarly in the next adjacent cell 4, the platinum mesh connects 5
and 4 electrically when pressed between the surfaces of 4 and 5 inside the gas
grooves 60. Finally the last sheet 5 of the stack is used for subsequent tapping
out power to outside the stack.
In another variation of the embodiment coating 64 of platinum is applied on
selected portion of the compressible sheet 6 after making suitable engrave on
the sheet for coating the platinum paste. The depth of the engrave where
platinum paste to be applied is maintained based on the compression ration of
the sheet and fired thickness of the platinum paste. Thus the engrave portion is

compensating the final platinum coating thickness so that the overall thickness of
sheet 6 is not altered after the platinum coating on it. Commercially available
platinum paste is used for the coating which is dried and matured by firing the
coated sheet at 850°C with 15 minute soak at peak temperature. Fired thickness
of the platinum coating is about 15 micron. An engrave of about 60 micron is
engraved on the felt sheet 6 by using commercial LASER engraving and cutting
machines, after compensating for the compressed thickness under light
compression while in use and coating on both sides.
In another variation of the embodiment coating of platinum or gold or palladium
or silver or any combination of these metals can also be used after making
suitable engraving on the compressible sheet 6 compensating the thickness for
the coating. Thin foil of these metals or their combinations or any high
temperature electrically conducting metal can also be used after making suitable
engrave on the compressible sheet 6 compensating the thickness for the foils.
In another variation of the embodiment the lateral connecting channels 61,61A,
62, 63, 63A and 62A (which is not visible in Figure 2 and 4) are distributed on
various other sides among the available four sides of the stack as in the example
of our description of the invention where the square-shaped cells are considered
only for illustration. The redistribution of the lateral channels to any one or more
sides either as opposite or same side configurations are easily possible for any
size and shape of the cells. The required configuration is to be selected based on

the size, shape and performance of the cells and applications of the device.
Accordingly the lateral gas flow grooves and vertical gas supply ducts to be
selected.
In another variation of the embodiment the sealing washers 7 and 8 in Figure 1
are made out of sealing glass. After mounting in the assembly as shown in
Figure 1 the assembly is put under compression load and then subjected to heat
treatment cycle for glass sealing. During the heat treatment the glass melts and
forms a rigid seal between the peripheral portions of members 5,6 and 9. The
rigid high pressure seal using the glass seal does not appreciably affect the
stress relaxation freedom of the delicate cell 4. The seal washer 8, when made
out of fully glass also seals one side border of the electrolyte 2 which is beneficial
for perfect gas sealing as long as it does not break due to relative movement of
9 and 4, if any during the dynamic operating condition. In such situation, the
sealing washer 8 can be made out of compressible sheet and can be bonded
with 6 and 9 with the same glass materials as in 7 within the zone 'B'.
According to the second embodiment of the invention the mildly leaked gas, if
any will be collected in a tiny gas tight chamber 68 comprising annular space
between support washer 9 and cell 4 and enclosed by compressible sheet 6 and
sealing gaskets 7 and 8. Connecting channels 62 and 62A on at least two sides
for each chamber giving connection to the vertical stack ducts for all such
chambers in the stack are used for purging and recycling the gas accumulated.

In another variation of the second embodiment Nitrogen or other gas is
connected to the chamber to maintain a slightly positive gas pressure in the
chamber preventing the mild leakage of gas incoming to the chamber.
According to the third embodiment of the invention the delicate cell 4 is firmly
supported by the two compressible sheets 6 and allowed to reduce its stresses
within the limit of light compressive load.
According to the fourth embodiment of the invention the one or more
compressible sheet 6 and one or more sturdy sheet 5 are joined together by
mechanically or by using paste materials such as high temperature cement. The
embodiment is illustrated in Figure 3 where the monolith member 65 is made by
joining the sturdy sheet 5 held in between two compressible sheets 6. Step C, C
and D introduced on sturdy sheet 5 are for replacing seal washers 7,7 and 8,
respectively. First the three steps are cut on the flat surfaces of Crofer 22 sheet
which is then subjected to roughening on both of its flat surfaces by mechanical
means and then sandwiched between two felt sheets. The sandwiched sheets
are pressed using a hydraulic press to form a monolithic sheet 65, which will be
having central sturdy portion and both sides flexible portion. This inventive
method makes less complicated assembly of stack because of reduction of type
of support components to merely two (65 and 79) per cell 4 of the assembly.

The assembly of stack even becomes simpler and less time consuming as shown
in Figure 4. Surface grooves 60 are either engraved or cut before joining 6,5 and
6 to make the member 65. All other features and advantages remain as
illustrated while describing the first embodiment and its various variations.

It is clear from the prior art and current industrial practice that several failure of
brittle part of the assembly of device, typically fracturing of ceramic electrolyte in
SOFC assembly during use is the main shortcoming of the current practice which
need to be avoided to improve the device more specifically the life and durability
of the SOFC stack assembly to a commercially acceptable level. Further it is
required to facilitate providing of adequate load to the seal assembly for proper
functioning of the seals without damaging the brittle components of the
assembly. Therefore the object of this invention is to devise a stress reducing
mounting assembly and methods of forming such assembly which adequately
seal the required parts of the device but does not transmit the same stress to the
relatively brittle part of the assembly unlike as presently practiced in the art.