U.S. patent application number 13/706211 was filed with the patent office on 2013-04-18 for fuel cell flow field plate including non-stoichiometric metal oxide layer.
This patent application is currently assigned to GM Global Technology Operations LLC. The applicant listed for this patent is GM Global Technology Operations LLC. Invention is credited to Mahmoud H. ABD ELHAMID, Gayatri Vyas DADHEECH, Youssef M. MIKHAIL, Thomas A. TRABOLD.
Application Number | 20130095251 13/706211 |
Document ID | / |
Family ID | 37545246 |
Filed Date | 2013-04-18 |
United States Patent
Application |
20130095251 |
Kind Code |
A1 |
DADHEECH; Gayatri Vyas ; et
al. |
April 18, 2013 |
FUEL CELL FLOW FIELD PLATE INCLUDING NON-STOICHIOMETRIC METAL OXIDE
LAYER
Abstract
A flow field plate or bipolar plate for a fuel cell that
includes a combination of non-stoichiometric and a conductive
material that makes the bipolar plate conductive, hydrophilic and
stable in the fuel cell environment. The non-stoichiometric and the
conductive material can be deposited on the plate as separate
layers or can be combined as a single layer. Either the
non-stoichiometric layer or the conductive layer can be deposited
first. In one embodiment, the conductive material is gold.
Inventors: |
DADHEECH; Gayatri Vyas;
(Bloomfield Hills, MI) ; ABD ELHAMID; Mahmoud H.;
(Troy, MI) ; TRABOLD; Thomas A.; (Pittsford,
NY) ; MIKHAIL; Youssef M.; (Sterling Heights,
MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GM Global Technology Operations LLC; |
Detroit |
MI |
US |
|
|
Assignee: |
GM Global Technology Operations
LLC
Detroit
MI
|
Family ID: |
37545246 |
Appl. No.: |
13/706211 |
Filed: |
December 5, 2012 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
11201767 |
Aug 11, 2005 |
8377607 |
|
|
13706211 |
|
|
|
|
11172021 |
Jun 30, 2005 |
|
|
|
11201767 |
|
|
|
|
Current U.S.
Class: |
427/453 ;
204/192.15; 427/115; 427/576; 427/596 |
Current CPC
Class: |
H01M 8/0202 20130101;
H01M 8/0226 20130101; H01M 8/0221 20130101; Y02E 60/50 20130101;
H01M 2008/1095 20130101; H01M 8/0204 20130101; H01M 8/021 20130101;
H01M 8/0228 20130101; H01M 2250/20 20130101; Y02T 90/40 20130101;
H01M 8/0206 20130101; H01M 8/04291 20130101 |
Class at
Publication: |
427/453 ;
427/115; 427/596; 427/576; 204/192.15 |
International
Class: |
H01M 8/02 20060101
H01M008/02 |
Claims
1. A method for making a flow field plate for a fuel cell, said
method comprising: providing a flow field plate being made of a
plate material; depositing a conductive layer on the flow field
plate; and depositing a non-stoichiometric metal oxide layer on the
conductive layer so as to make the plate conductive, hydrophilic
and stable in a fuel cell environment.
2. The method according to claim 1 wherein the plate material is
selected from the group consisting of stainless steel, titanium,
aluminum and a polymer-carbon composite based material.
3. The method according to claim 1 wherein the conductive layer is
a gold layer.
4. The method according to claim 1 wherein the non-stoichiometric
metal oxide layer provides a contact angle for water accumulating
in the flow channels to be below 20.degree..
5. The method according to claim 1 wherein the non-stoichiometric
metal oxide layer is resistant to surface contamination.
6. The method according to claim 1 wherein the conductive layer has
a thickness in the 2-10 nm range.
7. The method according to claim 1 wherein the non-stoichiometric
metal oxide layer and the conductive layer are deposited on the
flow field plate by a process selected from the group consisting of
an electron beam evaporation process, magnetron sputtering, a pulse
plasma process, plasma enhanced chemical vapor deposition, an
atomic layer deposition process, thermal spraying, spin coating,
dip coating and a sol-gel process.
8. The method according to claim 1 wherein the flow field plate is
selected from the group consisting of anode side flow field plates
and cathode side flow field plates.
9. The method according to claim 1 wherein the fuel cell is part of
a fuel cell stack on a vehicle.
10. The method according to claim 1 wherein the non-stoichiometric
metal oxide layer is TiO.sub.x where x is in the range of
0.1-6.
11. A method for making a flow field plate for a fuel cell, said
method comprising: providing a flow field plate being made of a
plate material; and depositing a mixture of a non-stoichiometric
metal oxide and a conductive material as a combined layer on the
flow field plate to make the plate conductive, hydrophilic and
stable in a fuel cell environment.
12. The method according to claim 11 wherein the plate material is
selected from the group consisting of stainless steel, titanium,
aluminum and a polymer-carbon composite based material.
13. The method according to claim 11 wherein the conductive
material is a gold layer.
14. The method according to claim 11 wherein the combined
non-stoichiometric metal oxide and the conductive layer are
deposited on the flow field plate by a process selected from the
group consisting of an electron beam evaporation process, magnetron
sputtering, a pulse plasma process, plasma enhanced chemical vapor
deposition, an atomic layer deposition process, thermal spraying,
spin coating, dip coating and a sol-gel process.
15. The method according to claim 11 wherein the flow field plate
is selected from the group consisting of anode side flow field
plates and cathode side flow field plates.
16. The method according to claim 11 wherein the fuel cell is part
of a fuel cell stack on a vehicle.
17. The method according to claim 11 wherein the non-stoichiometric
metal oxide is TiO.sub.x where x is in the range of 0.1-6.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional application of U.S. patent
application Ser. No. 11/201,767, titled, Fuel Cell Contact Element
Including a TiO.sub.2 Layer and a Conductive Layer, filed Aug. 11,
2005, which is a continuation-in-part application of U.S. patent
application Ser. No. 11/172,021, titled, Stable Conductive and
Hydrophilic Fuel Cell Contact Element, filed Jun. 30, 2005, now
abandoned.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates generally to bipolar plates for fuel
cells and, more particularly, to a bipolar plate for a fuel cell
that includes a non-stoichiometric metal oxide layer and a
conductive layer that combine to make the plate conductive,
hydrophilic and stable in a fuel cell environment.
[0004] 2. Discussion of the Related Art
[0005] Hydrogen is a very attractive fuel because it is clean and
can be used to efficiently produce electricity in a fuel cell. A
hydrogen fuel cell is an electro-chemical device that includes an
anode and a cathode with an electrolyte therebetween. The anode
receives hydrogen gas and the cathode receives oxygen or air. The
hydrogen gas is dissociated in the anode to generate free protons
and electrons. The protons pass through the electrolyte to the
cathode. The protons react with the oxygen and the electrons in the
cathode to generate water. The electrons from the anode cannot pass
through the electrolyte, and thus are directed through a load to
perform work before being sent to the cathode. The work acts to
operate the vehicle.
[0006] Proton exchange membrane fuel cells (PEMFC) are a popular
fuel cell for vehicles. The PEMFC generally includes a solid
polymer-electrolyte proton-conducting membrane, such as a
perfluorosulfonic acid membrane. The anode and cathode typically
include finely divided catalytic particles, usually platinum (Pt),
supported on carbon particles and mixed with an ionomer. The
catalytic mixture is deposited on opposing sides of the membrane.
The combination of the anode catalytic mixture, the cathode
catalytic mixture and the membrane define a membrane electrode
assembly (MEA). MEAs require certain conditions for effective
operation, including proper water management and humidification,
and control of catalyst poisoning constituents, such as carbon
monoxide (CO).
[0007] Several fuel cells are typically combined in a fuel cell
stack to generate the desired power. For the automotive fuel cell
stack mentioned above, the stack may include about two hundred fuel
cells. The fuel cell stack receives a cathode reactant gas,
typically a flow of air forced through the stack by a compressor.
Not all of the oxygen is consumed by the stack and some of the air
is output as a cathode exhaust gas that may include water as a
stack by-product. The fuel cell stack also receives an anode
hydrogen reactant gas that flows into the anode side of the
stack.
[0008] The fuel cell stack includes a series of flow field or
bipolar plates positioned between the several MEAs in the stack.
The bipolar plates include an anode side and a cathode side for
adjacent fuel cells in the stack. Anode gas flow channels are
provided on the anode side of the bipolar plates that allow the
anode gas to flow to the anode side of the MEA. Cathode gas flow
channels are provided on the cathode side of the bipolar plates
that allow the cathode gas to flow to the cathode side of the MEA.
The bipolar plates also include flow channels through which a
cooling fluid flows.
[0009] The bipolar plates are typically made of a conductive
material, such as stainless steel, titanium, aluminum, polymeric
carbon composites, etc., so that they conduct the electricity
generated by the fuel cells from one cell to the next cell and out
of the stack. Metal bipolar plates typically produce a natural
oxide on their outer surface that makes them resistant to
corrosion. However, the oxide layer is not conductive, and thus
increases the internal resistance of the fuel cell, reducing its
electrical performance. Also, the oxide layer makes the plate more
hydrophobic.
[0010] US Patent Application Publication No. 2003/0228512, assigned
to the assignee of this application and herein incorporated by
reference, discloses a process for depositing a conductive outer
layer on a flow field plate that prevents the plate from oxidizing
and increasing its ohmic contact. U.S. Pat. No. 6,372,376, also
assigned to the assignee of this application, discloses depositing
an electrically conductive, oxidation resistant and acid resistant
coating on a flow field plate. US Patent Application Publication
No. 2004/0091768, also assigned to the assignee of this
application, discloses depositing a graphite and carbon black
coating on a flow field plate for making the flow field plate
corrosion resistant, electrically conductive and thermally
conductive.
[0011] As is well understood in the art, the membranes within a
fuel cell need to have a certain relative humidity so that the
ionic resistance across the membrane is low enough to effectively
conduct protons. During operation of the fuel cell, moisture from
the MEAs and external humidification may enter the anode and
cathode flow channels. At low cell power demands, typically below
0.2 A/cm.sup.2, the water accumulates within the flow channels
because the flow rate of the reactant gas is too low to force the
water out of the channels. As the water accumulates, it forms
droplets that continue to expand because of the relatively
hydrophobic nature of the plate material. The contact angle of the
water droplets is generally about 90.degree. in that the droplets
form in the flow channels substantially perpendicular to the flow
of the reactant gas. As the size of the droplets increases, the
flow channel is closed off, and the reactant gas is diverted to
other flow channels because the channels are in parallel between
common inlet and outlet manifolds. Because the reactant gas may not
flow through a channel that is blocked with water, the reactant gas
cannot force the water out of the channel. Those areas of the
membrane that do not receive reactant gas as a result of the
channel being blocked will not generate electricity, thus resulting
in a non-homogenous current distribution and reducing the overall
efficiency of the fuel cell. As more and more flow channels are
blocked by water, the electricity produced by the fuel cell
decreases, where a cell voltage potential less than 200 mV is
considered a cell failure. Because the fuel cells are electrically
coupled in series, if one of the fuel cells stops performing, the
entire fuel cell stack may stop performing.
[0012] It is usually possible to purge the accumulated water in the
flow channels by periodically forcing the reactant gas through the
flow channels at a higher flow rate. However, on the cathode side,
this increases the parasitic power applied to the air compressor,
thereby reducing overall system efficiency. Moreover, there are
many reasons not to use the hydrogen fuel as a purge gas, including
reduced economy, reduced system efficiency and increased system
complexity for treating elevated concentrations of hydrogen in the
exhaust gas stream.
[0013] Reducing accumulated water in the channels can also be
accomplished by reducing inlet humidification. However, it is
desirable to provide some relative humidity in the anode and
cathode reactant gases so that the membranes in the fuel cells
remain hydrated. A dry inlet gas has a drying effect on the
membrane that could increase the cell's ionic resistance, and limit
the membrane's long-term durability.
[0014] It has been proposed by the present inventors to make
bipolar plates for a fuel cell hydrophilic to improve channel water
transport. A hydrophilic plate causes water in the channels to form
a thin film that has less of a tendency to alter the flow
distribution along the array of channels connected to the common
inlet and outlet headers. If the plate material is sufficiently
wettable, water transport through the diffusion media will contact
the channel walls and then, by capillary force, be transported into
the bottom corners of the channel along its length. The physical
requirements to support spontaneous wetting in the corners of a
flow channel are described by the Concus-Finn condition,
.beta. + .alpha. 2 < 90 .degree. , ##EQU00001##
where .beta. is the static contact angle and .alpha. is the channel
corner angle. For a rectangular channel .alpha./2=45.degree., which
dictates that spontaneous wetting will occur when the static
contact angle is less than 45.degree.. For the roughly rectangular
channels used in current fuel cell stack designs with composite
bipolar plates, this sets an approximate upper limit on the contact
angle needed to realize the beneficial effects of hydrophilic plate
surfaces on channel water transport and low load stability.
[0015] A design concern needs to be addressed when providing a
hydrophilic coating on bipolar plates in fuel cells. Because
hydrophilic coatings have a high surface energy, they will attract
particles and other contaminants entering the fuel cell from the
gaseous fuel and/or oxygen streams, from humidifiers and upstream
piping, or generated internally by other components, such as the
MEA, diffusion media, seals, etc. Accumulation of these
contaminants on the coating will, over time, significantly reduce
the hydropholicity of the coating. Even if provisions are made to
control contamination through the use of gas filtering and
ultra-clean components, it is unlikely that degradation of a
hydrophilic coating or other surface treatment would not occur
during the desired 6000 hour lifetime of a fuel cell.
SUMMARY OF THE INVENTION
[0016] In accordance with the teachings of the present invention, a
flow field plate or bipolar plate for a fuel cell is disclosed that
includes a combination of a non-stoichiometric metal oxide and a
conductive material that makes the bipolar plate conductive,
hydrophilic and stable in the fuel cell environment. The
non-stoichiometric metal oxide and the conductive material can be
deposited on the plate as separate layers or can be combined as a
single layer. Either the non-stoichiometric layer or the conductive
layer can be deposited first.
[0017] Additional features of the present invention will become
apparent from the following description and appended claims, taken
in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a cross-sectional view of a fuel cell in a fuel
cell stack that includes a bipolar plate having a metal oxide
coating that makes the plate conductive, hydrophilic and stable in
a fuel cell environment;
[0019] FIG. 2 is a graph with pressure on the horizontal axis and
contact resistance on the vertical axis showing electrical contact
resistance versus compression pressure for bipolar plates; and
[0020] FIG. 3 is a cross-sectional view of a fuel cell in a fuel
cell stack that includes a bipolar plate having a TiO.sub.2 layer
and a conductive layer that combine to make the plate conductive,
hydrophilic and stable in the fuel cell environment.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0021] The following discussion of the embodiments of the invention
directed to a bipolar plate for a fuel cell that includes a
non-stoichiometric metal oxide layer and a conductive layer for
making the bipolar plate conductive, hydrophilic and stable in a
fuel cell environment is merely exemplary in nature, and is in no
way intended to limit the invention or its applications or
uses.
[0022] FIG. 1 is a cross-sectional view of a fuel cell 10 that is
part of a fuel stack of the type discussed above. The fuel cell 10
includes a cathode side 12 and an anode side 14 separated by a
perfluorosulfonic acid membrane 16. A cathode side diffusion media
layer 20 is provided on the cathode side 12, and a cathode side
catalyst layer 22 is provided between the membrane 16 and the
diffusion media layer 20. Likewise, an anode side diffusion media
layer 24 is provided on the anode side 14, and an anode side
catalyst layer 26 is provided between the membrane 16 and the
diffusion media layer 24. The catalyst layers 22 and 26 and the
membrane 16 define an MEA. The diffusion media layers 20 and 24 are
porous layers that provide for input gas transport to and water
transport from the MEA. Various techniques are known in the art for
depositing the catalyst layers 22 and 26 on the diffusion media
layers 20 and 24, respectively, or on the membrane 16.
[0023] A cathode side flow field plate or bipolar plate 18 is
provided on the cathode side 12 and an anode side flow field plate
or bipolar plate 30 is provided on the anode side 14. The bipolar
plates 18 and 30 are provided between the fuel cells in the fuel
cell stack. A hydrogen reactant gas flow from flow channels 28 in
the bipolar plate 30 reacts with the catalyst layer 26 to
dissociate the hydrogen ions and the electrons. Airflow from flow
channels 32 in the bipolar plate 18 reacts with the catalyst layer
22. The hydrogen ions are able to propagate through the membrane 16
where they carry the ionic current through the membrane. The end
product is water, which does not have any negative impact on the
environment.
[0024] In this non-limiting embodiment, the bipolar plate 18
includes two sheets 34 and 36 that are stamped and welded together.
The sheet 36 defines the flow channels 32 and the sheet 34 defines
flow channels 38 for the anode side of an adjacent fuel cell to the
fuel cell 10. Cooling fluid flow channels 40 are provided between
the sheets 34 and 36, as shown. Likewise, the bipolar plate 30
includes a sheet 42 defining the flow channels 28, a sheet 44
defining flow channels 46 for the cathode side of an adjacent fuel
cell, and cooling fluid flow channels 48. In the embodiments
discussed herein, the sheets 34, 36, 42 and 44 are made of an
electrically conductive material, such as stainless steel,
titanium, aluminum, polymeric carbon composites, etc.
[0025] According to one embodiment of the present invention, the
bipolar plates 18 and 30 have a metal oxide layer 50 and 52,
respectively, that make the plates 18 and 30 conductive, corrosion
resistant, hydrophilic and stable in the fuel cell environment. In
one embodiment, the metal oxide layers 50 and 52 are doped with a
suitable dopant. The hydrophilicity of the layers 50 and 52 causes
the water within the flow channels 28 and 32 to form a film instead
of water droplets so that the water does not significantly block
the flow channel. Particularly, the hydrophilicity of the layers 50
and 52 decreases the contact angle of water accumulating in the
flow channels 32, 38, 28 and 46, preferably below 20.degree., so
that the reactant gases delivers the flow through the channels at
low loads.
[0026] Further, the dopant in the metal oxide is selected to
increase the conductivity of the layers 50 and 52. By making the
bipolar plates 18 and 30 more conductive, the electrical contact
resistance between the fuel cells and the losses in the fuel cell
are reduced, thus increasing cell efficiency. Also, an increase in
the conductivity of the layers 50 and 52 provides a reduction in
compression force in the stack can be provided, addressing certain
durability issues within the stack. In one embodiment, the dopant
is selected so that the conductivity of the layers 50 and 52 is
similar to gold.
[0027] Further, the dopant in the layers 50 and 52 is selected to
make the layers 50 and 52 stable, i.e., corrosion resistant.
Particularly, as is well understood in the art, hydrofluoric acid
(HF) is generated as a result of degradation of the
perfluorosulfonic ionomer in the membrane 16 during operation of
the fuel cell 10. The hydrofluoric acid has a corrosive effect on
some of the materials discussed herein, particularly material of
the bipolar plates 18 and 30. The metal oxide layers 50 and 52
prevent the bipolar plates 18 and 30, respectively, from
corroding.
[0028] Suitable metal oxides for the layers 50 and 52 include, but
are not limited to, hafnium dioxide (HfO.sub.2), zirconium dioxide
(ZrO.sub.2), aluminum oxide (Al.sub.2O.sub.3), tin oxide
(SnO.sub.2), tantalum pent-oxide (Ta.sub.2O.sub.5), niobium
pent-oxide (Nb.sub.2O.sub.5), molybdenum dioxide (MoO.sub.2),
iridium dioxide (IrO.sub.2), ruthenium dioxide (RuO.sub.2) and
mixtures thereof. Suitable dopants can be selected from materials
that can create suitable point defects, such as N, C, Li, Ba, Pb,
Mo, Ag, Au, Ru, Re, Nd, Y, Mn, V, Cr, Sb, Ni, W, Zr, Hf, etc. and
mixtures thereof. In one particular embodiment, the doped metal
oxide is niobium (Nb) and tantalum (Ta) doped titanium oxide
(TiO.sub.2) and fluorine (F) doped tin oxide (SnO.sub.2). The
amount of dopant in the layers 50 and 52 can be in the range of
0-10% of the composition of the layers 50 and 52 in one
embodiment.
[0029] FIG. 2 is a graph with pressure on the horizontal axis and
contact resistance on the vertical axis showing electrical contact
resistance versus compression pressure for bipolar plates.
Particularly, graph line 60 is a control contact resistance, graph
line 62 is the contact resistance for Nb doped TiO.sub.2 and graph
line 64 is the contact resistance for F doped SnO.sub.2.
[0030] In an alternate embodiment, the metal oxide layers 50 and 52
are non-stoichiometric metal oxide layers. The non-stoichiometric
metal oxide includes oxygen vacancies in the lattice structure of
the metal oxide. The metal oxide provides the hydrophilicity. The
vacancies allow electrons in the valence band to jump to the
conduction band of the metal oxide to provide the conductivity.
Further, the non-stoichiometric metal oxide reduces the hydrophobic
effect of contaminants adhering to the surface. Particularly, the
non-stoichiometric metal oxide acts as an oxidizing agent where the
contaminants get oxidized, similar to a self-cleaning window,
making the metal oxide layers 50 and 52 both hydrophilic and
conductive. A suitable example of a non-stoichiometric metal oxide
includes, but is not limited to, TiO.sub.x, where x is in the range
of 0.1-6.
[0031] According to the invention, TiO.sub.2 is one metal oxide
that can be used for the layers 50 and 52 that make the bipolar
plates 18 and 30 hydrophilic and stable in a fuel cell environment.
The conductivity of the bipolar plates 18 and 30 can be achieved by
providing a conductive material in combination with the TiO.sub.2
layers 50 and 52. In one embodiment, the conductive material can be
mixed with TiO.sub.2 to define the layers 50 and 52 and provide the
increased conductivity. Any suitable process can be used to mix the
TiO.sub.2 with the conductive material, such as a magnetron
sputtering process. The conductive material can be any suitable
conductive material for the purposes discussed herein, including,
but not limited to, gold (Au), silver (Ag), ruthenium (Ru), rhodium
(Rh), palladium (Pd), platinum (Pt), osmium (Os), iridium (Ir),
hafnium (Hf), rare earth metals, etc.
[0032] Further, a separate conductive layer can be deposited in
combination with the metal oxide layers 50 and 52. FIG. 3 is a
cross-sectional view of a fuel cell 70 similar to the fuel cell 10,
where like elements are identified by the same reference numeral.
In this embodiment, the metal oxide layers 50 and 52 are TiO.sub.2
layers. To make the plates 18 and 30 more conductive, a thin
conductive layer 72 is deposited on the metal oxide layer 50 and a
thin conductive layer 74 is deposited on the metal oxide layer 52.
In one embodiment, the conductive layers 72 and 74 are gold,
although other conductive materials may be applicable, such as
those mentioned above. Further, the conductive layers 72 and 74 are
very thin, generally on the order of 2-10 nm, so that the
hydrophilic nature of the metal oxide layers 50 and 52 is provided
through the conductive layers 72 and 74. In an alternate
embodiment, the conductive layers 72 and 74 can be deposited on the
bipolar plates 18 and 30, respectively, before the metal oxide
layers 50 and 52 are deposited on the plates 18 and 30.
[0033] Before the layers 50 and 52 are deposited on the bipolar
plates 18 and 30, the bipolar plates 18 and 30 are cleaned by a
suitable process, such as ion beam or magnetron sputtering, to
remove the resistive oxide film on the outside of the plates 18 and
30 that may have formed. The metal oxide layers 50 and 52 can be
deposited on the bipolar plates 18 and 30 by any suitable technique
including, but not limited to, physical vapor deposition processes,
chemical vapor deposition (CVD) processes, thermal spraying
processes, spin coating processes, dip coating processes and
sol-gel processes. Suitable examples of physical vapor deposition
processes include electron beam evaporation, magnetron sputtering
and pulsed plasma processes. Suitable chemical vapor deposition
processes include plasma enhanced CVD and atomic layer deposition
processes. In one embodiment, the layers 50 and 52 are deposited to
a thickness in the range of 5-1000 nm.
[0034] The foregoing discussion discloses and describes merely
exemplary embodiments of the present invention. One skilled in the
art will readily recognize from such discussion and from the
accompanying drawings and claims that various changes,
modifications and variations can be made therein without departing
from the spirit and scope of the invention as defined in the
following claims.
* * * * *