Electrochemical cell terminal block

Abstract

A terminal block assembly includes a lower layer comprising a first pair of mounting holes for mounting the lower layer on a pair of mounting posts, a middle layer comprising a second pair of mounting holes for mounting the middle layer on the pair of mounting posts, a terminal strip positioned between the lower layer and the middle layer, and an upper layer comprising a third pair of mounting holes for mounting the upper layer on the pair of mounting posts, the upper layer and the middle layer configured to clamp a wire therebetween.

Description

ELECTROCHEMICAL CELL TERMINAL BLOCKCROSS-REFERENCE TO RELATED PATENT APPLICATIONS

[0001] This application claims the benefit of and priority to U.S. Provisional Patent Application No. 63 / 651,751, filed May 24, 2024, which is incorporated by reference herein in its entirety.BACKGROUND

[0002] The present disclosure relates generally to the field of electrochemical cells. In particular, the present disclosure relates to a strain-relieving terminal block for an electrochemical cell stack.10003] A fuel cell is a type of electrochemical cell that uses an electrochemical reaction to convert chemical energy stored in a fuel such as hydrogen or methane into electrical energy. In general, fuel cells typically include an anode and a cathode separated by an electrolyte contained in an electrolyte matrix. Fuel flows to the anode via the first flow field, and an oxidant flows to the cathode via the second flow field. The fuel cell may oxidize the fuel in an electrochemical reaction, which releases a flow of electrons between the anode and cathode, thereby converting chemical energy into electrical energy. One type of fuel cell is a solid oxide fuel cell, which includes a solid electrolyte that transports oxide ions from the cathode to the anode. Oxygen in the oxidant supplied to the cathode forms oxide ions that are transported across the electrolyte to the anode, where the oxide ions react with hydrogen in the fuel to form water. The electrical energy produced by the flow of electrons can be captured and used to supply power to an electrical load. Multiple fuel cells may be arranged in a stack in order to produce a useful amount of power, and multiple stacks may be arranged in a module.[0004) Fuel cell stacks may include voltage leads (e.g., wires, cables, etc.) extending from the cells, through the housing of the fuel cell module, to a terminal point, so that the voltages of thecells can be measured to track the performance and health of the stack. In typical fuel cell systems, the voltage leads may directly connect the cells in the stacks to connection points on the inside of the fuel cell module housing and / or may pass through the module housing to a connector in a terminal enclosure on the outside of the module housing. However, during shipping and installation of the fuel cell stacks, the voltage leads may be mistakenly pulled out of their connections to the fuel cells, requiring time-consuming repair. Accordingly, it may be desirable to arrange the voltage leads in a way that reduces the likelihood that the leads will be pulled out during shipping and installation of the fuel cell system.SUMMARY

[0005] One aspect of the present disclosure relates to a terminal block assembly including a lower layer including a first pair of mounting holes for mounting the lower layer on a pair of mounting posts, a middle layer including a second pair of mounting holes for mounting the middle layer on the pair of mounting posts, a terminal strip positioned between the lower layer and the middle layer, and an upper layer including a third pair of mounting holes for mounting the upper layer on the pair of mounting posts, the upper layer and the middle layer configured to clamp a wire therebetween.

[0006] In some embodiments, the terminal block assembly further includes a pair of nuts configured to threadedly couple to the pair of mounting posts to clamp the upper layer to the middle layer. In some embodiments, the middle layer includes a clamping bar extending across an upper end of the middle layer. In some embodiments, the middle layer has a first width and the clamping bar has a second width that is less than the first width. In some embodiments, the middle layer includes a wire routing channel including a front portion on a first side of the clamping bar and a rear portion on a second side of the clamping bar, the wire routing channel configured to receive the wire on either side of the clamping bar. In some embodiments, a lower surface of the upper layer includes an arcuate channel including an arcuate cross-section. In some embodiments, the middle layer and the upper layer are configured to clamp the wire between the arcuate channel and the clamping bar.(0007) Another aspect of the present disclosure relates to a method of assembling a fuel cell system, the method including coupling a first portion of a terminal block assembly to a housing of a fuel cell stack assembly, the terminal block assembly including a conductive terminal strip, coupling a first wire from a fuel cell stack of the fuel cell stack assembly to a first side of the terminal strip, mounting the fuel cell stack in a module housing, clamping a second wire between a clamp layer of the terminal block assembly and the first portion of the terminal block assembly, and coupling a first end of the second wire to a second side of the terminal strip. In some embodiments, the first wire is coupled to the first side of the terminal strip before the fuel cell stack is mounted in the module housing. In some embodiments, the method further includes extending a second end of the second wire to the module housing. In some embodiments, coupling the first portion of the terminal block assembly to the housing of the fuel cell stack includes clamping the terminal strip between a lower layer and a middle layer of the terminal block assembly. In some embodiments, coupling the first wire to the first side of the terminal strip includes welding the first wire to the terminal strip. In some embodiments, coupling the second wire to the second side of the terminal strip includes welding the second wire to the terminal strip.

[0008] Another aspect of the present disclosure relates to a fuel cell system including a module housing, a fuel cell stack assembly positioned in the module housing and including a stack of fuel cells and a fuel cell stack housing, the fuel cell stack housing including an upper plate, a terminal block assembly including a lower portion coupled to the upper plate of the fuel cell stack housing and including a terminal strip and an upper layer configured to clamp onto the lower portion, a stack voltage lead including a first end coupled to the stack of fuel cells and a second end coupled to a first side of the terminal strip, and a module voltage lead clamped between the upper layer and the lower portion of the terminal block assembly and extending to the module housing, a first end of the module voltage lead coupled to a second side of the terminal strip. In some embodiments, at least one of the stack voltage lead or the module voltage lead is welded to the terminal strip. In some embodiments, the lower portion of the terminal block assembly includes a lower layer and a middle layer, and the terminal strip is positionedbetween the lower layer and the middle layer, in some embodiments, the fuel cell stack housing includes a pair of mounting posts, the pair of mounting posts extending through a pair of mounting holes in each of the lower layer, the middle layer, and the upper layer. In some embodiments, the fuel cell system further includes a first pair of nuts threadedly coupled to the pair of mounting posts and coupling the lower layer and the middle layer to the upper plate of the fuel cell stack housing. In some embodiments, the fuel cell system further includes a second pair of nuts threadedly coupled to the pair of mounting posts and configured to clamp the upper layer to the middle layer. In some embodiments, the lower layer, the middle layer, and the upper layer of the terminal block assembly are made of ceramic, and the terminal strip is made of stainless steel.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG. l is a side view of a typical fuel cell system.

[0010] FIG. 2 is a side view of a fuel cell system according to an exemplary embodiment.

[0011] FIG. 3 is a perspective view of a fuel cell stack assembly according to an exemplary embodiment.

[0012] FIG. 4 is a partially exploded view of the fuel cell stack assembly of FIG. 3.

[0013] FIG. 5 is a side view of a terminal block assembly according to an exemplary embodiment.

[0014] FIG. 6 is a side section view of a portion of the terminal block assembly of FIG. 5.

[0015] FIG. 7 illustrates a method of assembling a fuel cell system according to an exemplary embodiment.[001.6] It will be recognized that the figures are schematic representations for purposes of illustration. The figures are provided for the purpose of illustrating one or more implementationswith the explicit understanding that the figures will not be used to limit the scope of the meaning of the claims.DETAILED DESCRIPTION

[0017] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented here. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and made part of this disclosure.

[0018] FIG. 1 shows a prior art fuel cell system 10 that may include at least one module having a module housing 16, with each module containing one or more fuel cell stacks 12. The stack 12 includes multiple fuel cells, which are all electrically connected to the voltage leads (wires) 14. The voltage leads 14 from each fuel cell stack connect directly from their fuel cell stack connections to a connection point on the module housing 16. The voltage leads 14 may, for example, extend through a pass-through fitting in the wall of the module housing 16 and terminate at a terminal enclosure or connector on the outside of the module housing 16, where connections can be made to a computer or controller (e.g., the electrical balance of plant). An installer assembling the fuel cell system 10 typically installs the stack 12 inside the module housing 16, for example, by bolting the stack to the floor of the module housing 16. Then, the installer may connect each voltage lead 14 to the stack 12 and to the module housing 16. In some cases, the voltage leads may be couped to the stack 12 and / or to the module housing 16 before the stack 12 is bolted to the floor of the module housing 16.(0019] During installation and shipping, these voltage leads 14 can snag on other equipment or on the installers and be pulled out of their connections with the stack 12. This can delay the installation process and potentially damage the stack 12. Accordingly, it would be preferable for the fuel cell system 10 to manage the voltage leads 14 in a way that reduces the likelihood of the voltage leads being snagged and pulled on during shipping and installation and that reduces the likelihood of damage if the leads 14 are snagged.(0020] Referring now to FIG. 2, a fuel cell system 100 is shown, according to an exemplary embodiment. The fuel cell system 100 includes at least one fuel cell module that includes at least one fuel cell stack assembly 112 including a fuel cell stack of multiple fuel cells contained in a housing. The fuel cell system further includes a terminal block assembly 200 coupled to the housing of the fuel cell stack assembly 112. Rather than extending the voltage leads directly from the cells in the stack assembly 112 to a connection point at the module housing 116, the system 100 includes a first set of stack voltage leads 114 (or first wires) that couple the fuel cells to the terminal block assembly 200 and a second set of module voltage leads 115 (or second wires) that couple the terminal block assembly 200 to a connection point at the module housing 116. For example, the second voltage leads 115 may extend through a pass-through fitting in the module housing 16 wall and terminate at a terminal enclosure or connector on the outside of the module housing 16, where connections can be made to a computer or controller to receive data from the voltage leads 114, 115. The terminal block assembly 200 allows for the stack voltage leads 114 to be coupled to the fuel cells and the terminal block assembly 200 before the fuel cell stack assembly 112 is installed in the module housing 116 so that the connection points at which the voltage leads connect to the fuel cells do not need to be accessed after the fuel cell stack assemblies 112 are installed in the module housing. These connection points can be difficult to access due to space concerns and due to the other voltage leads that may interfere with access to the connection points. The stack voltage leads may extend along the side of the fuel cell stack assembly 112 relatively close to the stack assembly 112 (e.g., rather than extending across to the wall of the module housing 116) to reduce the likelihood of the stack voltage leads 114 being snagged and pulled during installation. The terminal block assembly 200 provides a singlelocation for the module voltage leads 115 to couple the stack assembly 112 to the module housing 116, rather than each stack voltage lead 114 extending from different points in the stack assembly 112 to the module housing 116. The module voltage leads 115 may also be relatively short in length compared to voltage leads that directly couple the cells to the module housing 116, which may further reduce the likelihood of snags.

[0021] Referring now to FIGS. 3-5, the terminal block assembly 200 is shown in further detail, according to an exemplary embodiment. As shown in FIG. 4, the terminal block assembly 200 includes three primary layers: a lower layer 202, a middle layer 204, and an upper layer 206. Each layer 202, 204, 206 includes respective mounting holes 208, 210, 212 for mounting the layers 202, 204, 206 to the housing of the fuel cell stack assembly 112. The housing of the fuel cell stack assembly 112 includes an upper plate 132 including two mounting posts 134, which may be threaded rods. The mounting holes 208, 210, 212 are sized and spaced apart such that the layers 202, 204, 206 can be positioned on the upper plate 132 with the mounting posts 134 extending through the mounting holes 208, 210, 212. As shown in FIG. 4, the upper plate 132 includes an aperture 136 between the mounting posts 134. As shown in FIG. 4, the lower layer 202 includes a boss 214 with a similar shape to that of the aperture 136 but slightly smaller. The boss 214 extends into the aperture to help align and position the lower layer 202 and to provide additional strength to the lower layer 202.100221 The lower layer 202 includes channels 216 shaped to receive electrically conductive terminal strips 218, which may be short segments of wire (e.g., square wire). Each channel 216 includes lips 220 at each end so that the terminal strips 218 cannot slide out the end of the channel 216. When the terminal block assembly 200 is installed on the upper plate 132 of the fuel cell stack assembly 112, the terminal strips 218 are sandwiched between the lower layer 202 and the middle layer 204 and held in place by the edges of the channels 216 and the lips 220 at the ends of the channels 216. As shown in FIG. 5, the stack voltage leads 114 are coupled to a front side 222 (or first side) of the terminal strips 218, and the module voltage leads 115 are coupled to a back side 224 (or second side) of the terminal strips 218. Thus, at various locations along the length of the stack 112 of fuel cells, a first end of each stack voltage lead 114 iscoupled to the stack 112, and a second end of each stack voltage lead 114 is coupled to a first side 222 of a terminal strip 218. A first end of each module voltage lead 115 is coupled to the second side 224 of the terminal strip 218, and a second end of each module voltage lead 115 extends to the module housing 116 and may be coupled to another terminal mounted to the housing 116 or may extend out of the housing 116. in some embodiments, the voltage leads 114, 115 may be welded to the terminal strips 218. In other embodiments, the voltage leads 114, 115 may be mechanically coupled to the terminals strips 218, for example, with fasteners or clamps. Together, the lower layer 202, the middle layer 204, and the terminal strips 218 may be referred to as a first portion or lower portion 203 of the terminal block assembly 200. In some embodiments, the lower layer 202 and the middle layer 204 may be a single, integrally formed component, with the terminal strips inserted into machined or molded channels.

[0023] As shown in FIG. 5 and 6, the module voltage leads 115 are routed through the gap between the middle layer 204 and the upper layer 206. Each end of the upper layer 206 is clamped down by a nut 225 onto the lower portion 203 of the terminal block assembly 200 (e.g., to the middle layer 204) to hold the module voltage leads 115 in place. Accordingly, the upper layer 206 may be referred to as a clamp layer. The nuts 225 may be threaded onto the mounting posts 134. This provides strain relief on the welded connection between the module voltage leads 115 and the terminal strips 218 (shown in FIG. 4). For example, if the portions 142 of the module voltage leads 115 that extend to the module housing 116 are pulled, the module voltage leads 115 remain clamped between the middle layer 204 and the upper layer 206. The force on the module voltage leads 115 may not be transferred past this point to the portion 144 of the module voltage leads 115 that are coupled to the terminal strips 218. Thus, the clamping of the module voltage leads 115 between the middle layer 204 and the upper layer 206 may reduce or eliminate any stress on the welded connections between the module voltage leads 115 and the terminal strips 218. This can prevent or reduce the likelihood of the module voltage leads 115 becoming disconnected from the terminal strips 218.

[0024] Referring now to FIG. 6, a cross-sectional view of a portion of the terminal block assembly 200 is shown, according to an exemplary embodiment. In particular, FIG. 6 shows aportion of a module voltage lead 115 clamped between the middle layer 204 and the upper layer 206. The middle layer 204 includes several wire (or lead) routing channels 226, each including a front portion 228 and a rear portion 230 on either side of a clamping bar 232. As shown in FIG. 3, the clamping bar 232 extends longitudinally along the length of an upper end of the middle layer 204 separating the front portion 228 and the rear portion 230 of the wire routing channels 226. The width of the clamping bar 232 (i.e., from left to right as shown in FIG. 6) is less than the overall width of the middle layer 204. This may increase the clamping pressure on the module voltage lead 115 by reducing the contact area of the module voltage leads 115 clamped between the upper layer 206 and the middle layer 204. Adjacent wire routing channels 226 are separated by separator walls 231 (shown in further detail in FIG. 4).

[0025] The upper layer 206 includes an arcuate channel 234 (e.g., a channel with an arcuate cross-section, as shown in FIG. 6) that extends longitudinally along the length of the upper layer 206. When the upper layer 206 is clamped down onto the middle layer 204, the module voltage leads 115 are clamped between the arcuate channel 234 and the clamping bar 232. The edges of the clamping bar 232 may be chamfered, filleted, or otherwise tapered to reduce the pressure on the module voltage lead 115. Thus, each module voltage lead 115 extends from the module housing 116 into the front portion 228 of the respective wire routing channel 226, is clamped between the clamping bar 232 and the arcuate channel 234, and extends out of the rear portion 230 of the wire routing channel 226 to be welded or otherwise coupled to the terminal strip 218. The middle layer 204 contacts the upper surfaces of the separator walls 231 (e.g., at the edges of the arcuate channel 234), separating the adjacent wire routing channels 226 such that the adjacent module voltage leads do not come in contact with each other.

[0026] Referring again to FIG. 4, the terminal block assembly 200 further includes a pair of nuts 236 that can be threaded to the mounting posts 134 to clamp the middle layer 204 and the lower layer 202 to the upper plate 132. As discussed above, clamping the terminal strips 218 between the middle layer 204 and the lower layer 202 may allow the stack voltage leads 114 to be coupled (e.g., welded) to the terminal strips 218 before the stack assembly 112 is installed in the module housing 116. As shown in FIG. 5, each side of the terminal block assembly 200 mayinclude a second nut 238, which may function as a locknut as well as a spacer that stops the ends of the upper layer 206 from bending when the nut 225 is tightened onto the upper layer 206. The terminal block assembly 200 may further include washers to help distribute the clamping force of the nuts 225, 236, 238 and to act as additional spacers between the middle layer 204 and the upper layer 206. Additionally, in the embodiments shown, the terminal block assembly 200 includes a top plate 240 to further distribute the force from the nuts 225.

[0027] Because the terminal block assembly 200 is made to be used in high-temperature fuel cell systems, such as solid oxide fuel cell systems, the materials must be able to withstand very high temperatures (e.g., 600-1000 degrees Celsius) and potentially harsh oxidative environments. For example, plastic components would melt or bum at these temperatures. Further, a metal springbased connection between the voltage leads 114, 115 and the terminal block assembly 200 may lose its compressive force as the spring heats up. Additionally, a spring-based or compressionbased connection between the voltage leads 114, 115 and the terminal block assembly 200 may allow oxidation of the leads 114, 115 and any other metal connectors to penetrate into the connection, weakening the electrical connection.

[0028] Accordingly, the layers 202, 204, 206 of the terminal block assembly 200 may be made of a dielectric ceramic material such as alumina (aluminum oxide, AI2O3, etc.). Alumina is a dielectric material that will insulate the voltage leads 114, 115 from the adjacent leads 114, 115 while also being highly heat-resistant. The remaining components, including the mounting posts 134, the terminal strips 218, the nuts 225, 236, 238, the washers, and the top plate 240 may be made of a corrosion-resistant material such as stainless steel. For example, the nuts 225, 236, 238 and the washers, as well as the upper plate 132 of the stack assembly 112, may be made of 316 stainless steel, the top plate 240 may be made of 434 stainless steel, and the terminal strips 218 may be made of 430 stainless steel. The stainless steel may resist oxidation and corrosion when the fuel cell system 100 is in use. Because the voltage leads 114, 115 may be welded to the terminal strips 218 before the fuel cell system 100 is operated, any oxidation of the terminal strips 218 or voltage leads 114, 115 would be on the outside of the welded connection and would not weaken the connection.

[0029] In some embodiments, the fuel cell stack assembly 112 may include hundreds of fuel cells (e.g., 350 fuel cells), which may be grouped into sub-stacks (e.g., 10 sub-stacks of 35 fuel cells) with each sub-stack having a stack voltage lead 114 coupled thereto. In other embodiments, each fuel cell may have a separate voltage lead 114 coupled thereto. In some embodiments, more than one terminal block assembly 200 may be coupled to the housing of the fuel cell stack assembly 112. For example, a second terminal block assembly 200 may be coupled to the opposite end of the upper plate 132 of the housing and coupled to voltage leads 114 extending from the opposite side of the fuel cell stack.100301 Referring now to FIG. 7, a method 300 of assembling a fuel cell system (e.g., fuel cell system 100) is shown, according to an exemplary embodiment. At operation 302 of the method 300, a first portion of a terminal block assembly including a terminal strip is coupled to a fuel cell stack housing. For example, the fuel cell stack housing may include a mounting plate (e.g., upper plate 132) that includes or is coupled to a pair of mounting posts (e.g., mounting posts 134). The first portion of the terminal block assembly may include mounting holes shaped and positioned to receive the mounting posts. The first portion of the terminal block assembly may be positioned on the mounting posts and secured to the mounting plate by fasteners (e.g., nuts 236). The first portion of the terminal block assembly may include a lower layer (e.g., lower layer 202) and a middle layer (e.g., middle layer 204) that each includes mounting holes shaped and positioned to receive the mounting posts. The lower layer may be positioned on the mounting posts, then the terminal strip or strips may be positioned on the lower layer, and then the middle layer may be positioned over the terminal strips and clamped onto the lower layer to secure the terminal strip or strips between the lower layer and the middle layer. Nuts may be threadedly coupled to the mounting posts to secure and clamp the layers to the mounting plate and the other layers.[00311 At operation 304 of the method 300, a first wire (e.g., a stack voltage lead 114) is coupled to a first side of the terminal strip. The first wire may extend from the terminal strip to the fuel cell stack and may be configured to transmit electrical signals from the fuel cell stack to the terminal strip. Coupling the first wire to the terminal strip may include welding (e.g., spotwelding) the first wire to the terminal strip. Operation 304 may be repeated for multiple first wires, each coupled to a different fuel cell or group of fuel cells in the fuel cell stack and to a different terminal strip. At operation 306 of the method 300, the fuel cell stack is mounted in a module housing. In some embodiments, operation 306 may be performed after operations 302 and 304. Coupling the stack voltage leads 114 to the terminal block assembly before installing the fuel cell stack in the module housing may reduce the likelihood that the voltage leads 114 are mistakenly pulled out of the fuel cell stack during installation and shipping. The module housing may be configured to contain multiple (e.g., up to 48) fuel cell stacks, each of which may include one or more first wires (e.g., stack voltage leads 114) coupled to terminal strips in a terminal block assembly mounted to a mounting plate of a respective stack housing.

[0032] At operation 308 of the method 300, a second wire (e.g., a module voltage lead 115) is clamped between a top layer (e.g., upper layer 206) of the terminal block assembly and the lower portion of the terminal block assembly (e.g., between the top layer and the middle layer). The second wire may be clamped near the first end of the second wire, such that a small length of the second wire (including the first end) extends beyond the top layer of the terminal block assembly. At operation 310 of the method 300, the first end of the second wire is coupled to a second side of the terminal strip. Coupling the first end of the second wire to the second side of the terminal strip may include welding the second wire to the terminal strip. In some embodiments, operations 308 and 310 may be performed before mounting the fuel cell stack in the module housing in operation 306. For example, after coupling the first end of the second wire to the terminal strip, a second end of the second wire may be temporarily secured to the stack before mounting the fuel cell stack to the module housing to reduce the likelihood of snagging during installation of the fuel cell stack. After installation of the fuel cell stack, the second end of the second wire may be decoupled from the fuel cell stack and the method may proceed to operation 312.

[0033] At operation 312 of the method 300, the second end of the second wire is extended to the module housing. The second end of the second wire may be coupled to a terminal block at the module housing and / or may extend through the module housing to make a connection outside thehousing. In some embodiments, a third wire connected to a terminal or connector on the outside of the module housing and fed through a pass-through to the inside of the module housing may be connected to the second end of the second wire. Additional connections may be made to the terminal connection by, for example, a computer or controller, which may receive voltage data from the fuel cells in the stack via the voltage leads. Operations 308, 310, and 312 may each be repeated for multiple second wires, each corresponding to a first wire coupled to one of the terminal strips.

[0034] Because the second wire is clamped between the top layer of the terminal block assembly and the lower portion of the terminal block assembly, tension on the second wire between the terminal block assembly and the module housing may be reacted by the friction caused by the clamping force and may not reach the connection between the first end of the second wire and the terminal strip. Thus, the terminal block assembly provides strain relief for the connection between the second wire and the terminal strip, reducing stress on the connection and reducing the likelihood that the connection is broken due to pulling on the second wire.100351 In some embodiments, the method 300 may include additional operations, may repeat operations, or may not include every operation listed above. For example, the terminal block assembly may include multiple terminal strips, and operations 304 may be repeated to connect multiple stack voltage leads from the fuel cell stack to the terminal strips. In some embodiments of the method 300, the module voltage leads may be previously wired to the module housing before operations 308 and 310, and the method may not include operation 312. In some embodiments, the method 300 may be repeated multiple times to install multiple fuel cell stacks in the module housing. In some embodiments, the method 300 may not include operation 308. While the upper layer of the terminal block assembly may not provide strain relief in such an embodiment, the benefits of wiring the stack voltage leads to the terminal block (e.g., before installing the fuel cell stack assembly in the module housing) may still be realized.

[0036] While this specification contains specific implementation details, these should not be construed as limitations on the scope of what may be claimed but rather as descriptions offeatures specific to particular implementations. Certain features described in this specification in the context of separate implementations can also be implemented in combination in a single implementation. Conversely, various features described in the context of a single implementation can also be implemented in multiple implementations separately or in any suitable subcombination. Moreover, although features may be described as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can, in some cases, be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.

[0037] As utilized herein with respect to structural features (e.g., to describe shape, size, orientation, direction, relative position, etc.), the terms “approximately,” “about,” “substantially,” and similar terms are meant to cover minor variations in structure that may result from, for example, the manufacturing or assembly process and are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and claimed are considered to be within the scope of the disclosure as recited in the appended claims.

[0038] It should be noted that the term “exemplary” and variations thereof, as used herein to describe various embodiments, are intended to indicate that such embodiments are possible examples, representations, or illustrations of possible embodiments (and such terms are not intended to connote that such embodiments are necessarily extraordinary or superlative examples).

[0039] The term “coupled” and variations thereof, as used herein, means the joining of two members directly or indirectly to one another. Such joining may be stationary (e.g., permanent or fixed) or moveable (e.g., removable or releasable). Such joining may be achieved with the two members coupled directly to each other, with the two members coupled to each other using a separate intervening member and any additional intermediate members coupled with oneanother, or with the two members coupled to each other using an intervening member that is integrally formed as a single unitary body with one of the two members. If “coupled” or variations thereof are modified by an additional term (e.g., directly coupled), the generic definition of “coupled” provided above is modified by the plain language meaning of the additional term (e.g., “directly coupled” means the joining of two members without any separate intervening member), resulting in a narrower definition than the generic definition of “coupled” provided above. Such coupling may be mechanical, electrical, or fluidic.

[0040] References herein to the positions of elements (e.g., “top,” “bottom,” “above,” “below”) are merely used to describe the orientation of various elements in the FIGURES. It should be noted that the orientation of various elements may differ according to other exemplary embodiments, and that such variations are intended to be encompassed by the present disclosure.[0041 J Although the figures and description may illustrate a specific order of method steps, the order of such steps may differ from what is depicted and described, unless specified differently above. Also, two or more steps may be performed concurrently or with partial concurrence, unless specified differently above.

Claims

WHAT IS CLAIMED IS:

1. A terminal block assembly comprising: a lower layer comprising a first pair of mounting holes for mounting the lower layer on a pair of mounting posts; a middle layer comprising a second pair of mounting holes for mounting the middle layer on the pair of mounting posts; a terminal strip positioned between the lower layer and the middle layer; and an upper layer comprising a third pair of mounting holes for mounting the upper layer on the pair of mounting posts, the upper layer and the middle layer configured to clamp a wire therebetween.

2. The terminal block assembly of claim 1, further comprising a pair of nuts configured to threadedly couple to the pair of mounting posts to clamp the upper layer to the middle layer.

3. The terminal block assembly of either one of claims 1 or 2, wherein the middle layer comprises a clamping bar extending across an upper end of the middle layer.

4. The terminal block assembly of claim 3, wherein the middle layer has a first width and the clamping bar has a second width that is less than the first width.

5. The terminal block assembly of either one of claims 3 or 4, wherein the middle layer includes a wire routing channel comprising a front portion on a first side of the clamping bar and a rear portion on a second side of the clamping bar, the wire routing channel configured to receive the wire on either side of the clamping bar.

6. The terminal block assembly of any one of claims 3-5 wherein a lower surface of the upper layer includes an arcuate channel comprising an arcuate cross-section.

7. The terminal block assembly of claim 6, wherein the middle layer and the upper layer are configured to clamp the wire between the arcuate channel and the clamping bar.

8. A method of assembling a fuel cell system, the method comprising: coupling a first portion of a terminal block assembly to a housing of a fuel cell stack assembly, the terminal block assembly including a conductive terminal strip; coupling a first wire from a fuel cell stack of the fuel cell stack assembly to a first side of the terminal strip; mounting the fuel cell stack in a module housing; clamping a second wire between a clamp layer of the terminal block assembly and the first portion of the terminal block assembly; and coupling a first end of the second wire to a second side of the terminal strip.

9. The method of claim 8, wherein the first wire is coupled to the first side of the terminal strip before the fuel cell stack is mounted in the module housing.

10. The method of either one of claims 8 or 9, further comprising extending a second end of the second wire to the module housing.

11. The method of any one of claims 8-10, wherein coupling the first portion of the terminal block assembly to the housing of the fuel cell stack comprises clamping the terminal strip between a lower layer and a middle layer of the terminal block assembly.

12. The method of any one of claims 8-11, wherein coupling the first wire to the first side of the terminal strip comprises welding the first wire to the terminal strip.

13. The method of any one of claims 8-12, wherein coupling the second wire to the second side of the terminal strip comprises welding the second wire to the terminal strip.

14. A fuel cell system comprising: a module housing; a fuel cell stack assembly positioned in the module housing and comprising a stack of fuel cells and a fuel cell stack housing, the fuel cell stack housing comprising an upper plate; a terminal block assembly comprising: a lower portion coupled to the upper plate of the fuel cell stack housing and comprising a terminal strip; and an upper layer configured to clamp onto the lower portion; a stack voltage lead comprising a first end coupled to the stack of fuel cells and a second end coupled to a first side of the terminal strip; and a module voltage lead clamped between the upper layer and the lower portion of the terminal block assembly and extending to the module housing, a first end of the module voltage lead coupled to a second side of the terminal strip.

15. The fuel cell system of claim 14, wherein at least one of the stack voltage lead or the module voltage lead is welded to the terminal strip.

16. The fuel cell system of either one of claims 14 or 15, wherein the lower portion of the terminal block assembly comprises a lower layer and a middle layer, and the terminal strip is positioned between the lower layer and the middle layer.

17. The fuel cell system of claim 16, wherein the fuel cell stack housing includes a pair of mounting posts, the pair of mounting posts extending through a pair of mounting holes in each of the lower layer, the middle layer, and the upper layer.

18. The fuel cell system of claim 17, further comprising a first pair of nuts threadedly coupled to the pair of mounting posts and coupling the lower layer and the middle layer to the upper plate of the fuel cell stack housing.

19. The fuel cell system of either one of claims 17 or 18, further comprising a second pair of nuts threadedly coupled to the pair of mounting posts and configured to clamp the upper layer to the middle layer.

20. The fuel cell system of any one of claims 16-19, wherein the lower layer, the middle layer, and the upper layer of the terminal block assembly are made of ceramic, and the terminal strip is made of stainless steel.

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