SINGLE CONDUCTOR LAYER CELL-TO-CELL INTERCONNECT FOR ELECTRIC VEHICLE POWER SUPPLY OR OTHER POWER SUPPLY

An apparatus includes an interconnect assembly configured to receive and retain multiple batteries. The interconnect assembly includes a retainer configured to receive portions of the batteries and a conductive interconnect layer carried by the retainer. The conductive interconnect layer includes a first layer of conductive material having a first thickness and a second layer of conductive material having a second thickness less than the first thickness. The first and second layers of conductive material are attached together to form the conductive interconnect layer. The second layer of conductive material includes multiple interconnects configured to be coupled to cathodes and anodes of the batteries.

TECHNICAL FIELD

This disclosure relates generally to power supplies. More specifically, this disclosure relates to a single conductor layer cell-to-cell interconnect for an electric vehicle power supply or other power supply.

BACKGROUND

An electric vehicle includes a power supply that provides electrical power to one or more electric motors and other components of the electric vehicle. In some cases, the power supply may include a large number of battery cells (referred to as “batteries”) that are connected in various series and parallel combinations. During operation, the batteries collectively operate to provide the electrical power for the electric vehicle. Unfortunately, electric vehicle power supplies can suffer from a number of shortcomings in their designs.

SUMMARY

This disclosure provides a single conductor layer cell-to-cell interconnect for an electric vehicle power supply or other power supply.

In a first embodiment, an apparatus includes an interconnect assembly configured to receive and retain multiple batteries. The interconnect assembly includes a retainer configured to receive portions of the batteries and a conductive interconnect layer carried by the retainer. The conductive interconnect layer includes a first layer of conductive material having a first thickness and a second layer of conductive material having a second thickness less than the first thickness. The first and second layers of conductive material are attached together to form the conductive interconnect layer. The second layer of conductive material includes multiple interconnects configured to be coupled to cathodes and anodes of the batteries.

In a second embodiment, a system includes one or more power supply modules configured to provide electrical power. Each power supply module includes an interconnect assembly configured to receive and retain multiple batteries. The interconnect assembly includes (i) a retainer configured to receive portions of the batteries, (ii) a conductive interconnect layer carried by the retainer, and (iii) terminal connectors electrically coupled to the batteries and configured to provide at least a portion of the electrical power. The conductive interconnect layer includes a first layer of conductive material having a first thickness and a second layer of conductive material having a second thickness less than the first thickness. The first and second layers of conductive material are attached together to form the conductive interconnect layer. The second layer of conductive material includes multiple interconnects configured to be coupled to cathodes and anodes of the batteries.

In a third embodiment, a method includes inserting multiple batteries into an interconnect assembly that is configured to receive and retain the batteries. The interconnect assembly includes a retainer configured to receive portions of the batteries and a conductive interconnect layer carried by the retainer. The conductive interconnect layer includes a first layer of conductive material having a first thickness and a second layer of conductive material having a second thickness less than the first thickness. The first and second layers of conductive material are attached together to form the conductive interconnect layer. The method also includes attaching interconnects in the second layer of conductive material to cathodes and anodes of the batteries.

DETAILED DESCRIPTION

FIGS.1through17, described below, and the various embodiments used to describe the principles of this disclosure are by way of illustration only and should not be construed in any way to limit the scope of this disclosure. Those skilled in the art will understand that the principles of this disclosure may be implemented in any type of suitably arranged device or system.

As noted above, an electric vehicle includes a power supply that provides electrical power to one or more electric motors and other components of the electric vehicle. In some cases, the power supply may include a large number of battery cells (referred to as “batteries”) that are connected in various series and parallel combinations. During operation, the batteries collectively operate to provide the electrical power for the electric vehicle. Unfortunately, electric vehicle power supplies can suffer from a number of shortcomings in their designs.

As particular examples of various shortcomings, an electric vehicle power supply needs to ensure that electrical isolation exists between positive and negative pathways to and from the batteries in order to avoid the creation of short circuits. However, electric vehicle power supplies often have tight clearances and limited visibility, which can make it difficult to properly couple electrical pathways to the batteries (such as via laser welding). Also, certain types of batteries (such as lithium ion batteries) are temperature-sensitive, and some electric vehicle power supplies may allow batteries to reach significantly different temperatures, which can negatively impact power supply performance. Further, electric vehicle power supplies may often include temperature and voltage sensors to monitor characteristics of the batteries, but the temperature and voltage sensors often use different harnesses and wiring. Moreover, electric vehicle power supplies may be implemented using multiple modules, where each module includes a number of batteries and the modules themselves can be coupled in series and parallel arrangements to provide desired electrical power. However, connection points for the modules may be complex, which increases the size, weight, and cost of the power supplies. In addition, electric vehicle power supplies may lack adequate structural integrity in some cases. Finally, electric vehicle power supplies may suffer from various uniformity issues, such as electrical current or resistance network uniformity issues, that can negatively affect the operation of the power supplies.

This disclosure describes various embodiments of a single conductor layer cell-to-cell interconnect for an electric vehicle power supply or other power supply. As described in more detail below, an interconnect or interconnect assembly couples multiple batteries together in series and parallel arrangements as needed or desired to form a power supply module. One or more instances of the power supply module may be used to form a power supply for an electric vehicle or other larger system that uses electrical power. Each battery has a cathode and an anode that couple to a single conductive layer in an interconnect assembly, and the conductive layer includes conductive fingers and various positive and negative interconnects or connection tabs at appropriate locations to form series and parallel connections with the batteries. Terminal connectors are also provided for convenient coupling of each interconnect assembly to other interconnect assemblies or other components of a larger system.

The embodiments of the interconnect assemblies described below may substantially or completely overcome many of the shortcomings discussed above. For example, the interconnect assemblies help to ensure that electrical isolation exists between positive and negative pathways to and from the batteries, even in the presence of tight clearances. Also, the interconnect assemblies may provide improved visibility, which can help to support operations such as laser welding. Moreover, various improvements may be used to help batteries maintain more consistent temperatures within the interconnect assemblies, and integrated temperature and voltage sensing can be used to monitor the characteristics of the batteries. Further, multiple interconnect assemblies may be used to form multiple modules of a power supply, and the interconnect assemblies provide for simple connections of the modules in series and parallel arrangements. In addition, the interconnect assemblies may provide for improved structural integrity, and various uniformity issues (such as electrical current or resistance network uniformity issues) can be improved in the interconnect assemblies.

FIG.1illustrates an example interconnect assembly100for use in an electric vehicle or other system according to this disclosure. The interconnect assembly100may, for example, represent or form one power supply module, and one or more power supply modules may be used to form a power supply for an electric vehicle or other system.

As shown inFIG.1, the interconnect assembly100includes two sub-modules102a-102b, where each sub-module102a-102bis used to receive and form electrical connections with a number of batteries104. Each sub-module102a-102bmay receive and form electrical connections with any suitable number of batteries104. In some cases, for instance, each sub-module102a-102bmay receive and retain one hundred and thirty eight batteries104, and the interconnect assembly100collectively may receive and retain two hundred and seventy six batteries104(although this is for illustration only). Also, any suitable series and parallel connections may be defined by the interconnect assembly100for the batteries104. In some cases, for example, the interconnect assembly100may define a “6S46P” configuration, meaning the interconnect assembly100includes six series-coupled collections of forty six batteries104coupled in parallel. In that example, each sub-module102a-102bmay define a “3S46P” configuration, meaning each sub-module102a-102bincludes three series-coupled collections of forty six batteries104coupled in parallel. However, other arrangements of batteries104may be used in each sub-module102a-102band in the interconnect assembly100.

Each battery104may represent a cylindrical battery having both positive and negative terminals of the battery (meaning a cathode and an anode of the battery) at one end of the battery. For instance, each battery104may include a cathode forming a raised central portion of one end of the battery104and an anode forming a thin annular region around the cathode. Note, however, that the size and shape of the batteries104may vary as needed or desired.

A coldplate106is used to help cool the batteries104and other components of the interconnect assembly100. The coldplate106may be formed from any suitable material, such as one or more materials having high thermal conductivity. The coldplate106may also be formed in any suitable manner. In this example, the coldplate106includes or is thermally coupled to a cell retainer108aforming part of the sub-module102aand a cell retainer108bforming part of the sub-module102b. Each cell retainer108a-108brepresents a structure that is configured to receive portions of multiple batteries104and to retain the batteries104within the cell retainer108a-108b. In this way, the cell retainers108a-108bhelp to maintain the batteries104at desired positions within the interconnect assembly100. Each cell retainer108a-108bmay be formed from any suitable material, such as one or more materials having high thermal conductivity, and in any suitable manner.

In this example, each sub-module102a-102bincludes one or more projections110, and each projection110defines an opening. When the projections110of the sub-modules102a-102bare aligned, one or more rods112may be inserted through the openings of the projections110in order to help secure the sub-modules102a-102btogether (at least at the illustrated end of the interconnect assembly100). Each projection110and each rod112may have any suitable size and shape. Note, however, that other mechanisms for securing the sub-modules102a-102btogether may be used here.

Each sub-module102a-102balso respectively includes a terminal connector114a-114b. The terminal connectors114a-114brepresent structures that can be electrically coupled to cables, wiring, or other electrical conductors in order to electrically couple the interconnect assembly100to other interconnect assemblies or other components in a larger system. In this example, for instance, the terminal connector114arepresents a negative terminal, and the terminal connector114brepresents a positive terminal. Coupling the terminal connectors114a-114bto electrical conductors allows the interconnect assembly100to output electrical power to the larger system. If multiple interconnect assemblies100are coupled together in series, the interconnect assemblies100can operate to collectively produce a larger electrical voltage. If multiple interconnect assemblies100are coupled together in parallel, the interconnect assemblies100can operate to collectively produce a larger electrical current. Various series and parallel arrangements of the interconnect assemblies100may be used to achieve the desired electrical voltage and electrical current. Each terminal connector114a-114brepresents any suitable structure configured to be coupled to an electrical conductor, such as a threaded stud or other threaded post.

Various stiffening plates116may be used to provide structural reinforcement and increase the structural integrity of the interconnect assembly100. For example, the stiffening plates116may be coupled to other components of the interconnect assembly100like the coldplate106(such as via an adhesive), and the stiffening plates116may operate to reduce or prevent deformations of the interconnect assembly100or otherwise improve the structural integrity of the interconnect assembly100. Each stiffening plate116may be formed from any suitable material, such as one or more metals, and in any suitable manner.

A control board118is coupled to one or more sensor assemblies120a-120b. The one or more sensor assemblies120a-120bmay be used to sense temperature, voltage, or other characteristics in the interconnect assembly100. In some cases, each sensor assembly120a-120bcan support integrated temperature and voltage sensing. The control board118may include at least one microprocessor, microcontroller, digital signal processor (DSP), application specific integrated circuit (ASIC), field programmable gate array (FPGA), or other components for processing or outputting measurements from the one or more sensor assemblies120a-120b. For example, the control board118may shut down or otherwise modify the operation of the interconnect assembly100(or provide information to an external component that can shut down or otherwise modify the operation of the interconnect assembly100) in response to an over-voltage or over-temperature condition. The control board118may also operate to pass measurements from the sensor assemblies120a-120bto an external component, such as an external control system, for use in controlling the interconnect assembly100.

AlthoughFIG.1illustrates one example of an interconnect assembly100for use in an electric vehicle or other system, various changes may be made toFIG.1. For example, the interconnect assembly100and each of its individual components may have any suitable size, shape, and dimensions. Also, the interconnect assembly100may be used with any suitable number of batteries in any suitable arrangement to produce any suitable electrical voltage and electrical current. Various additional features and example implementations of various features of the interconnect assembly100are provided below.

FIG.2illustrates an example portion200of a sub-module102ain an interconnect assembly100according to this disclosure. The portion200of the sub-module102ashown inFIG.2includes various structures used to form electrical connections with some of the batteries104in the interconnect assembly100. This portion200of the sub-module102amay represent the outermost portion of the interconnect assembly100on the back side of the interconnect assembly100as shown inFIG.1. A similar structure may be used in the sub-module102bto form electrical connections with other batteries104in the interconnect assembly100, but the polarities of the electrical connections may be reversed as described below. The similar structure used in the sub-module102bmay represent the closest portion of the interconnect assembly100on the front side of the interconnect assembly100as shown inFIG.1.

As shown inFIG.2, this portion200of the sub-module102aincludes an interconnect retainer202, an adhesive layer204, and two layers206a-206bcollectively forming a single conductive interconnect layer206. The interconnect retainer202generally represents a structure that cooperates with the cell retainer108ato hold batteries104in place within the sub-module102aand to hold conductive interconnects of the conductive interconnect layer206at suitable locations relative to the batteries104in the sub-module102a. A similar interconnect retainer may cooperate with the cell retainer108bto hold batteries104in place within the sub-module102band to hold conductive interconnects of a single conductive interconnect layer at suitable locations relative to the batteries104in the sub-module102b. The interconnect retainer202may be formed from any suitable material, such as one or more electrically-insulative materials like plastic, and in any suitable manner.

The adhesive layer204represents a layer of adhesive that can be used to secure the conductive interconnect layer206to the interconnect retainer202. As described in more detail below, in some embodiments, the adhesive layer204may be placed into recesses or grooves of the interconnect retainer202and used to couple conductive fingers and other portions of the conductive interconnect layer206to the interconnect retainer202. The adhesive layer204includes any suitable adhesive that couples components together. Note, however, that other mechanisms may be used to secure the conductive interconnect layer206to the interconnect retainer202.

The layers206a-206brepresent layers of one or more conductive materials that can be coupled to one another in order to form a single conductive layer that is carried by the interconnect retainer202and electrically coupled to the batteries104in the sub-module102a. As described in more detail below, the layer206amay represent a layer of conductive material that can transport larger amounts of electrical current, and the layer206bmay represent a layer of conductive material that can transport smaller amounts of electrical current. For example, the layer206amay have thicker and/or wider portions of conductive material compared to the layer206b. The layers206a-206bmay be formed using any suitable conductive material, such as aluminum or copper, and in any suitable manner. In some cases, the layer206amay represent a layer of aluminum that is about three millimeters thick, and the layer206bmay represent a layer of aluminum that is about 0.25 millimeters thick. In these or other embodiments, the layer206bmay represent a foil that can be easily manipulated to couple portions of the layer206bto the batteries104.

At one end of the conductive interconnect layer206is the terminal connector114a, which allows the conductive interconnect layer206to be coupled to an electrical conductor as described above. At the opposite end of the conductive interconnect layer206are multiple conductive forks208, which are used to couple the conductive interconnect layer206of the sub-module102ato the conductive interconnect layer of the sub-module102b. The conductive interconnect layer of the sub-module102bincludes the terminal connector114b. The conductive forks208thereby help to form electrical connections between the sub-modules102a-102bso that a complete electrical pathway exists between the terminal connectors114a-114b.

AlthoughFIG.2illustrates one example of a portion200of a sub-module102ain an interconnect assembly100, various changes may be made toFIG.2. For example, the sub-module102aand each of its individual components may have any suitable size, shape, and dimensions. Also, this portion200of the sub-module102amay be modified to support use with other suitable numbers of batteries and batteries in other suitable configurations.

FIGS.3A and3Billustrate an example conductive interconnect layer206of a sub-module102ain an interconnect assembly100according to this disclosure. As shown inFIGS.3A and3B, the conductive interconnect layer206is formed here using four distinct conductive structures302-308, each of which includes elongated conductive fingers310. The conductive fingers310of different conductive structures302-308are interdigitated or interleaved with one another. The elongated fingers310are also interleaved in terms of polarity, meaning one elongated finger310and an adjacent elongated finger310have opposite polarities in terms of connections to the batteries104. In this example, the conductive structure302represents a negative connection structure, meaning the conductive structure302is coupled to negative terminals of batteries104. The conductive structure308represents a positive connection structure, meaning the conductive structure308is coupled to positive terminals of batteries104. The conductive structures304and306represent series connection structures, meaning each conductive structure304and306is coupled to positive terminals of batteries104on one side of the structure and to negative terminals of batteries104on the other side of the structure.

The elongated fingers310are conductive and are able to transport electrical currents from batteries104(during use of the interconnect assembly100) or to the batteries104(during charging of the batteries104). In this example, the elongated fingers310are electrically coupled to three types of connections to the batteries104. Positive or single-cathode interconnects312are represented using generally circular structures, and each interconnect312connects to a positive terminal of one battery104. Single negative or single-anode interconnects314are represented using thinner generally rectangular structures, and each interconnect314connects to a negative terminal of one battery104. Double negative or double-anode interconnects316are represented using wider generally rectangular structures, and each interconnect316connects to two negative terminals of two batteries104.

FIG.4illustrates example interconnects312-316of a conductive interconnect layer206to batteries104in an interconnect assembly100according to this disclosure. As can be seen here, each battery104may include a raised cathode402and an annular anode404. Each interconnect312can be sized and shaped to be coupled to the cathode402of a single battery104without also contacting the anodes404of any batteries104. Each interconnect314can be sized and shaped to be coupled to the anode404of a single battery104without also contacting the cathodes402any batteries104. Each interconnect316can be sized and shaped to be coupled to the anodes404of two neighboring batteries104without also contacting the cathodes402of any batteries104. Bends in the interconnects312-316allow the interconnects312-316to extend from the conductive fingers310to the batteries104. The conductive fingers310are positioned above the batteries104and therefore do not physically contact the cathodes402or anodes404of the batteries104. As described below, in some embodiments, laser welding may be used to physically attach the interconnects312-316to the cathodes402and anodes404of the batteries104.

The conductive structures304and306shown inFIGS.3A and3Balso include balancing conductors318. Each balancing conductor318electrically couples neighboring fingers310in the associated conductive structure304and306. The balancing conductors318are useful since various fingers310of the conductive structures304and306are coupled to different numbers of batteries104. For example, in the conductive structure304, the bottom left finger310can be coupled to sixteen batteries (since there are eight double-anode interconnects316), but the bottom right finger310can be coupled to fourteen batteries (since there are fourteen cathode interconnects312). Without the balancing conductors318, the different numbers of batteries104coupled to the fingers310of the conductive structures304and306may create various issues, such as when temperatures of the batteries104vary due to some batteries104sourcing or sinking more current than other batteries104. The balancing conductors318allow electrical currents to flow as needed between different fingers310in order to accommodate different numbers of batteries104coupled to the fingers310. Each balancing conductor318may be formed from any suitable conductive material, such as aluminum or copper, and in any suitable manner.

The conductive structures302-308shown inFIGS.3A and3Bfurther include various projections320extending from the fingers310, and each projection320includes an opening. As described below, the openings of the projections320can be sized, shaped, and positioned to receive pins or other structures extending from the interconnect retainer202. When these pins or other structures are inserted through the openings of the projections320, this helps to hold the fingers310of the conductive interconnect layer206at desired locations on the interconnect retainer202.

In addition, various ones of the conductive structures302-308shown inFIGS.3A and3Bmay include conductive tabs322, which represent locations where one of the sensor assemblies120a-120bcan be coupled to the conductive structures302-308. Each conductive tab322therefore allows the associated sensor assembly120a-120bto capture voltage measurements at the location of the conductive tab322within the conductive interconnect layer206. Each conductive tab322may be formed from any suitable conductive material, such as aluminum or copper, and in any suitable manner. Note that the number and positions of the conductive tabs322shown here are for illustration only and that any number of conductive tabs322may be used at one or more suitable locations within the interconnect assembly100.

The specific arrangement of interconnects312-316here supports the creation of specific series and parallel paths through the batteries104.FIGS.5A through5Dillustrate example connections formed by a conductive interconnect layer206in a first sub-module102aof an interconnect assembly100according to this disclosure. InFIG.5A, all four conductive structures302-308are shown as being coupled to one hundred and thirty eight batteries104in the “3S46P” configuration. As noted above, this configuration means that each sub-module102a-102bincludes three series-coupled collections of forty six batteries104coupled in parallel, although other numbers of batteries104in series and in parallel may be used as needed or desired.

InFIG.5B, the first collection of batteries104coupled in parallel is shown. Here, the conductive structure302is coupled to the anodes404of the batteries104using single-anode and double-anode interconnects314and316. The conductive structure304is coupled to the cathodes402of the same batteries104using cathode interconnects312. With these connections, the batteries104in the first collection are coupled in parallel with one another.

InFIG.5C, the second collection of batteries104coupled in parallel is shown. Here, the conductive structure304is coupled to the anodes404of the batteries104using single-anode and double-anode interconnects314and316. The conductive structure306is coupled to the cathodes402of the same batteries104using cathode interconnects312. With these connections, the batteries104in the second collection are coupled in parallel with one another. Also, the second collection of batteries104is coupled in series with the first collection of batteries104.

InFIG.5D, the third collection of batteries104coupled in parallel is shown. Here, the conductive structure306is coupled to the anodes404of the batteries104using single-anode and double-anode interconnects314and316. The conductive structure308is coupled to the cathodes402of the same batteries104using cathode interconnects312. With these connections, the batteries104in the third collection are coupled in parallel with one another. Also, the third collection of batteries104is coupled in series with the first and second collections of batteries104.

As discussed above, the sub-module102bmay include similar components as the sub-module102a, but the polarities of the connections to the batteries104in the sub-module102bcan be reversed.FIG.6illustrates example connections formed by a conductive interconnect layer206′ in a second sub-module102bof an interconnect assembly100according to this disclosure. In this example, the conductive interconnect layer206′ in the second sub-module102bis formed using four distinct conductive structures302′-308′, which are similar to the conductive structures302-308described above (except positive connections to batteries104have been replaced with negative connections to batteries104and vice versa). This helps to provide the proper voltage change from the terminal connector114bto conductive forks208′ of the sub-module102band the proper voltage change from the conductive forks208of the sub-module102ato the terminal connector114a.

As can be seen inFIGS.3A through6, the conductive interconnect layers206and206′ of the interconnect assembly100allow for desired series and parallel connections to be formed with batteries104in both sub-modules102a-102b. Because of this, the batteries104can be used to provide a desired amount of electrical power to an electric vehicle or other powered system. In other words, the conductive interconnect layers206and206′ of the interconnect assembly100can be used to clearly define a circuit that provides a desired amount of electrical power.

AlthoughFIGS.3A through6illustrate example conductive interconnect layers206and206′ of sub-modules102a-102bin an interconnect assembly100, various changes may be made toFIGS.3A through6. For example, the conductive interconnect layers206and206′ can vary based on the number and arrangement of batteries being used. As a particular example, one of the conductive structures304,306and one of the conductive structures304′,306′ may be omitted if each sub-module102a-102bincludes two collections of batteries in series. As another particular example, additional series connection structures may be used if each sub-module102a-102bincludes more than three collections of batteries in series. Also, the use of single-cathode, single-anode, and double-anode interconnects312-316is for illustration only, and each interconnect312-316may have any desired form.

FIGS.7A through7Dillustrate an example mechanism for securing a conductive interconnect layer206to an interconnect retainer202in an interconnect assembly100according to this disclosure. While the mechanism here is described as being used in the sub-module102a, the same type of mechanism may be used in the sub-module102b(although different sub-modules may use different mechanisms if needed or desired).

As noted above, the conductive structures302-308forming the conductive interconnect layer206may include projections320with openings. As shown inFIGS.7A through7D, the interconnect retainer202includes various pins702projecting from a surface of the interconnect retainer202. At least portions of the pins702can fit through the corresponding openings of the projections320. In some cases, the pins702can fit snugly or tightly into the openings of the projections320, which helps to hold the conductive structures302-308forming the conductive interconnect layer206in place on the interconnect retainer202.

Among other things, this can help to hold the various interconnects312-316of the conductive interconnect layer206at suitable locations for laser welding or otherwise during coupling of the interconnects312-316to the batteries104. This can also help to reduce or prevent one of the conductive structures302-308from contacting another of the conductive structures302-308and creating a short circuit. In addition, because the conductive structures302-308forming the conductive interconnect layer206can be held in place, there may be less restrictive tolerances placed on the manufacture of the conductive structures302-308, which can help to simplify construction and reduce costs of the interconnect assembly100.

AlthoughFIGS.7A through7Dillustrate one example of a mechanism for securing a conductive interconnect layer206to an interconnect retainer202in an interconnect assembly100, various changes may be made toFIGS.7A through7D. For example, any other suitable mechanism may be used to secure the conductive interconnect layer206to the interconnect retainer202.

FIGS.8A through8Fillustrate an example mechanism for electrically isolating a conductive interconnect layer206from batteries104(except through defined interconnects312-316) according to this disclosure. While the mechanism here is described as being used in the sub-module102a, the same type of mechanism may be used in the sub-module102b(although different sub-modules may use different mechanisms if needed or desired).

As shown inFIGS.8A and8B, the interconnect retainer202includes a number of hexagonal, honeycomb, or other structures802. Each structure802is configured to receive a portion of a battery104. The walls of the structures802can be used to contact the sides or tops of the batteries104in order to help retain and reduce or prevent movement of the batteries104within the interconnect assembly100.

As shown inFIGS.8A through8F, flanges804with recesses or grooves806are positioned above the structures802. The flanges804can be defined in areas where the fingers310of the conductive interconnect layer206will be positioned. The recesses or grooves806are configured to receive the adhesive layer204, and the conductive interconnect layer206is mounted to the interconnect retainer202using the adhesive layer204.

The flanges804help to hold the conductive interconnect layer206above the batteries104so that the conductive interconnect layer206does not form undesired electrical connections to the batteries104. Instead, electrical connections between the fingers310and the batteries104are formed using the interconnects312-316, which extend from the fingers310to the batteries104. As can be seen inFIG.8D, the flanges804may cover portions of the anodes404of various batteries104, which again can help to avoid undesired electrical connections to the batteries104.

In this example, the interconnect retainer202can also include raised paths808that correspond to locations of the balancing conductors318of the conductive interconnect layer206. Again, the paths808can help to separate the balancing conductors318from the batteries104. As a result, the interconnect retainer202can provide relatively large barriers between the conductive interconnect layer206and the batteries104.

AlthoughFIGS.8A through8Fillustrate one example of a mechanism for electrically isolating a conductive interconnect layer206from batteries104(except through defined interconnects312-316), various changes may be made toFIGS.8A through8F. For example, the structures802of the interconnect retainer202may have one or more shapes other than hexagonal or honeycomb.

FIG.9illustrates an example technique for forming a conductive interconnect layer206of an interconnect assembly100according to this disclosure. While the technique here is described as being used to form the conductive interconnect layer206, the same type of technique may be used to form the conductive interconnect layer206′ (although different techniques may be used if needed or desired).

As shown inFIG.9, two layers206a′-206b′ represent portions of the layers206a-206bdescribed above. In this example, the layers206a′-206b′ are used to form the conductive structure304. Here, the layers206a′-206b′ can be welded or otherwise connected to one another in order to form the conductive structure304, which represents part of the conductive interconnect layer206. The same approach can be used to connect other portions of the layers206a-206bto form the other conductive structures302,306,308of the conductive interconnect layer206.

This approach allows parts of the more flexible layer206bto be manipulated and positioned as needed for attachment to the batteries104while allowing the thicker layer206ato be more rigid and carry larger electrical currents. As the lengths of the fingers310increase in order to couple the fingers310to more batteries104, higher currents would cause the thinner layer206b(by itself) to increase in temperature. Coupling the thinner layer206bto the thicker layer206ahelps to reduce the temperature increase in the conductive interconnect layer206. This may also allow cheaper materials (such as aluminum rather than copper) to be used in the conductive interconnect layer206. The use of the balancing conductors318as described above can also help to distribute electrical currents in the fingers310more evenly, which can help to reduce temperature differentials between the fingers310in the conductive interconnect layer206.

AlthoughFIG.9illustrates one example of a technique for forming a conductive interconnect layer206of an interconnect assembly100, various changes may be made toFIG.9. For example, the form of the conductive interconnect layer206can vary based on the specific interconnections needed to form specific electrical paths through a specified number of batteries104.

FIGS.10A and10Billustrate example sensor assemblies120a-120bin an interconnect assembly100according to this disclosure. As shown inFIGS.10A and10B, each of the sensor assemblies120a-120bmay respectively include a ribbon cable1002a-1002band a connector1004a-1004b. Each ribbon cable1002a-1002brepresents a flat structure that can carry wires and other components of the sensor assembly120a-120b. Each connector1004a-1004brepresents an electrical interface between the sensor assembly120a-120band the control board118or other device.

Each ribbon cable1002a-1002bis respectively coupled to a thermistor1006a-1006b, which represents a resistor having a resistance that varies with temperature. Each thermistor1006a-1006bmay be physically attached to the side of a battery104, conductive finger310, or other component in a sub-module102a-102bin order to sense the temperature of that battery104, finger310, or other component. Each ribbon cable1002a-1002bis also respectively coupled to multiple voltage contact points1008a-1008b, which represent double-sided exposed copper traces or other conductive structures that can be bonded or otherwise attached to various conductive tabs322. Thus, the ribbon cable1002a-1002bcan be used to transport electrical signals between the control board118and the thermistor1006a-1006b/contact points1008a-1008b, which allows the control board118to obtain temperature and voltage measurements associated with the batteries104.

In this example, the sensor assembly120aincludes a longer ribbon cable1002aand one additional voltage contact point1008arelative to the sensor assembly120b. This is because the sensor assembly120amay be used to measure the voltage at the end of the sub-module102ahaving the conductive forks208. Because the sub-modules102a-102bare coupled together via the conductive forks208and208′, voltage measurements around the conductive forks208should be substantially equal to voltage measurements around the conductive forks208′ (with only very minor resistive losses or other losses expected). As a result, the sensor assembly120bdoes not need to include a longer ribbon cable1002band an additional contact point1008bto measure the voltage at the end of the sub-module102bhaving the conductive forks208′. This can help to reduce the cost of the sensor assembly120band reduce the number of sensor measurements to be processed. However, nothing prevents the sensor assembly120bfrom matching the design of the sensor assembly120a.

In some embodiments, each sensor assembly120a-120bmay be fabricated as a flexible printed circuit (FPC). The flat profiles of the flexible printed circuits, as well as the micron-scale thickness of their materials, add little mass to the overall assembly and provide versatility for packaging. Also, the flexibility of this design allows the portion of each sensor assembly120a-120bcontaining the thermistor1006a-1006bto be bent downward and make contact directly with an outer surface of a battery104. To help ensure that each thermistor1006a-1006bstays in place on a battery104, a pressure-sensitive adhesive or other adhesive can be installed on a cover layer of a flexible printed circuit opposite the thermistor1006a-1006b. The relatively thin thicknesses of the various components of the sensor assembly120a-120bhelps to ensure that there is a very small thermal resistance between the battery104on which the thermistor1006a-1006bis mounted and the thermistor1006a-1006bitself. This can enable a very fast response time for the thermistor1006a-1006b. To help ensure that the adhesive retains its cleanliness, a silicone backing or other protector can be applied on the adhesive and removed right before installation of the thermistor1006a-1006bonto a battery104.

AlthoughFIGS.10A and10Billustrate examples of sensor assemblies120a-120bin an interconnect assembly100, various changes may be made toFIGS.10A and10B. For example, each sensor assembly120a-120bmay include any desired number of thermistors and any desired number of voltage contact points. Also, nothing prevents a single sensor assembly that wraps partially or completely around the interconnect assembly100from being used.

FIGS.11A and11Billustrate an example mechanism for coupling an interconnect assembly100to a larger system according to this disclosure. As described above, the conductive structures302and302′ forming portions of the conductive interconnect layers206and206′ in the interconnect assembly100include the terminal connectors114a-114b. In this design, the terminal connectors114a-114bare integrated directly into the conductive interconnect layers206and206′ of the interconnect assembly100. The portions of the conductive structures302and302′ coupled to the terminal connectors114a-114bcan be suitably thick to provide adequate coupling points for external cables or other conductors. Moreover, this approach eliminates the need for any extra parts or assemblies, other than the addition of the posts forming the terminal connectors114a-114b. This helps to provide improved flexibility and reduced cost for the interconnect assembly100.

FIGS.12A and12Billustrate an example mechanism for electrically coupling sub-modules102a-102bof an interconnect assembly100according to this disclosure. The mechanism shown here may, for example, be used to electrically couple the conductive forks208and208′ of the sub-modules102a-102b. As shown inFIGS.12A and12B, the conductive forks208and208′ of the sub-modules102a-102bcan be electrically coupled together using multiple busbars1202. Each busbar1202represents an electrically conductive structure that can be attached to the forked ends of the conductive forks208and208′. In this example, each busbar1202includes multiple posts1204, such as threaded studs, which can be inserted into the forked ends of one of the conductive forks208and one of the conductive forks208′. Connectors1206, such as nuts and washers, can be secured to the posts1204in order to couple the busbars1202to the conductive forks208and208′. Once secured, the busbars1202can be used to transport electrical currents between the conductive forks208and208′ of the sub-modules102a-102b. An interconnect retainer202′ is also shown here, which represents the interconnect retainer in the sub-module102b.

These approaches can reduce or eliminate the need for metal forming operations to complete the fabrication of the interconnect assembly100, and these approaches can simplify the equipment used to fabricate the interconnect assembly100. Also, these approaches can reduce or eliminate the need for complex electrical connectors that would need to be capable of absorbing tolerance stack-up between interconnect assemblies100while still providing reliable low-resistance electrical joints. Here, the connectors1206can be sized to provide adequate clamping force needed to overcome any preloading that may be introduced from the tolerance stack while still meeting any electrical resistance requirements.

AlthoughFIGS.11A and11Billustrate one example of a mechanism for coupling an interconnect assembly100to a larger system andFIGS.12A and12Billustrate one example of a mechanism for electrically coupling sub-modules102a-102bof an interconnect assembly100, various changes may be made toFIGS.11A through12B. For example, while two busbars1202are shown here, more busbars1202may be used if more batteries104are present or if the batteries104are arranged differently in the interconnect assembly100.

FIG.13illustrates an example structural reinforcement for an interconnect assembly100according to this disclosure. As shown inFIG.13, a portion of the sub-module102aand the sub-module102bare shown as being coupled together. A stiffening plate116ais secured to one side of the sub-module102busing an adhesive layer1302, and another stiffening plate116bis secured to the opposite side of the sub-module102busing an adhesive layer1304. While not shown here, the same approach may be used to couple additional stiffening plates to opposite sides of the sub-module102a. The stiffening plates can link the sub-modules102a-102bto the coldplate106, such as via structural adhesive joints, on either side of the interconnect assembly100. Moving structural connections to the sides of the interconnect assembly100helps to reduce or avoid the need for widening spaces between the batteries104to fit structural components. This also reduces the need for precision application of adhesive in the adhesive layers1302and1304since the adhesive layers1302and1304are away from critical areas near the tops of the batteries104.

In addition to the structural reinforcement provided by the stiffening plates, structural reinforcement can be provided by the adhesion of the conductive interconnect layers206,206′ to the interconnect retainers202,202′ in the sub-modules102a-102b. As shown inFIGS.8A through8Fand discussed above, the interconnect retainers202,202′ can include flanges804with recesses or grooves806, which receive adhesive that couples the conductive interconnect layers206,206′ to the interconnect retainers202,202′. This helps to secure the conductive interconnect layers206,206′ to the interconnect retainers202,202′ in the sub-modules102a-102b. In some cases, the recesses or grooves806may be relatively deep (such as about 0.5 millimeters) to capture adhesive and limit unwanted squeeze out of the adhesive. The recesses or grooves806also increase the surface area on the interconnect retainers202,202′ available for bonding with the adhesive.

AlthoughFIG.13illustrates one example of a structural reinforcement for an interconnect assembly100, various changes may be made toFIG.13. For example, other forms of structural reinforcement may be provided with or used by the interconnect assembly100.

FIGS.14A and14Billustrate example current distributions in interconnect assemblies according to this disclosure. As shown inFIG.14A, it is assumed here that each finger310in the conductive structure308of the sub-module102ais coupled directly to a corresponding finger310in the conductive structure308′ of the sub-module102b. Since electrical current naturally follows the path of least resistance, even though the fingers310of the sub-modules102a-102bare coupled together, the bulk of an electrical current1402will flow directly between the terminal connectors114a-114b. As a result, batteries104in the central portion of the sub-modules102a-102bmay be loaded somewhat more than other batteries104. This can result in higher operating temperatures in these batteries104, which may limit their power throughput and contribute to advanced cell aging or reduced cycle life.

As shown inFIG.14B, by using two busbars1202and two conductive forks208,208′ in each sub-module102a-102bto couple the sub-modules102a-102btogether, various electrical currents1404-1406will flow more evenly between the terminal connectors114a-114b(compared toFIG.14A). This helps to load-balance the batteries104in the interconnect assembly100better, which can help to provide more consistent operating temperatures in the batteries104and improve power throughput and cell aging/cycle life.

AlthoughFIGS.14A and14Billustrate examples of current distributions in interconnect assemblies, various changes may be made toFIGS.14A and14B. For example, other current distributions are possible with other arrangements of batteries104, conductive forks208,208′, and busbars1202.

FIGS.15A and15Billustrate an example technique for laser welding of interconnects312-316to batteries104in an interconnect assembly100according to this disclosure. As shown inFIG.4above, each of the interconnects312-316may include two approximately 90° bends in order to bring large portions of the interconnects312-316into suitable positions for attachment to the batteries104. This can be accomplished as shown inFIGS.15A and15Busing one or more clamps1502-1504, each of which can include a passageway allowing a laser source1506to provide a welding laser beam1508through the clamp1502-1504. The laser beam1508can thereby weld an interconnect312-316being depressed by the clamp1502-1504onto an underlying portion of a battery104. Since each clamp1502-1504can depress a portion of the interconnect312-316being welded, this helps to ensure good physical contact between the interconnect312-316and the underlying portion of the battery104.

The design of the interconnect assembly100itself also provides adequate space for the clamps1502-1504to be used to weld the various interconnects312-316to the batteries104. If necessary, the design of the interconnect assembly100, such as the widths or heights of the fingers310, can be adjusted to provide adequate space for the clamps1502-1504while still supporting adequate current-transporting and temperature-handling capabilities of the conductive interconnect layers206,206′.

Note that each of the interconnects312-316shown inFIG.4may have a small portion that projects substantially laterally from its associated finger310prior to being bent downward. This can provide an amount of flexibility or bend relief in order to comply with the application of the clamps1502-1504. In some cases, the portions of the interconnects312-316that project substantially laterally from the fingers310may extend by about 1.0 to about 1.4 millimeters, although other lengths of these portions of the interconnects312-316may be used.

The interconnect retainers202,202′ and the cell retainers108a,108bcan also cooperate to help hold the batteries104in desired positions while reducing possible movements of the batteries104. This can help to maintain tops of the batteries104substantially perpendicular to the welding laser beams1508used to weld the interconnects312-316to the batteries104. For example, the hexagonal, honeycomb, or other structures802of the interconnect retainers202,202′ can help reduce the possible variation in the positions of the batteries104within the structures802. In some embodiments, the hexagonal shape of the structures802also helps to enable a more uniform nominal thickness in the interconnect retainers202,202′ and limit cell friction. The nominal thickness of the walls of the structures802may remain relatively constant, and this can be useful in various fabrication processes for the interconnect retainers202,202′, such as plastic injection molding, as it reduces uneven cooling in a mold and therefore reduces warp. This allows for tighter tolerances to be enforced without sacrificing part costs, which make this approach even more suitable for controlling the battery array composite tolerance.

FIG.16illustrates an example portion of a cell retainer108a,108bthat forms part of a coldplate106in an interconnect assembly100according to this disclosure. As shown inFIG.16, each cell retainer108a,108bmay include a number of recesses1602, and each recess1602can be sized and shaped to receive an end portion of a battery104. The spacing of the recesses1602defines the density of the batteries104in the interconnect assembly100. In some embodiments, the recesses1602may be somewhat oversized relative to the outer diameters of the batteries104, which may facilitate faster or easier insertion of the batteries104into the recesses1602. While this may allow for some displacement of the batteries104, the use of the hexagonal, honeycomb, or other structures802in the interconnect retainers202,202′ can help the batteries104to be suitably positioned for attachment to the interconnects312-316.

Even if some very small displacements to the tops of the batteries104may exist in the interconnect assembly100, a manufacturing or processing system may be configured to accommodate these displacements. For example, a vision system1510as shown inFIG.15Bmay be used to identify the locations of the cathodes402and anodes404of the batteries104in order to facilitate accurate welding of the interconnects312-316to the cathodes402and anodes404. For example, in some cases, the vision system1510may use the outer diameter of the batteries104to identify weld locations. In other cases, each battery104may include a cell gasket that is visible along the inner edge of the battery's anode404, and the vision system1510may use the locations of the cell gaskets to identify weld locations.

Note that the ability to use features like outer diameters or cell gasket locations depends on the ability of the vision system1510to actually view those features of the batteries104. In the various embodiments of the interconnect assembly100described above, the outer diameters and/or cell gaskets of the batteries104may be viewed much more easily compared to other approaches. This helps to facilitate manufacture of the interconnect assembly100in a more automated manner.

AlthoughFIGS.15A and15Billustrate one example of a technique for laser welding of interconnects312-316to batteries104in an interconnect assembly100andFIG.16illustrates one example portion of a cell retainer108a,108bthat forms part of a coldplate106in an interconnect assembly100, various changes may be made toFIGS.15A,15B, and16. For example, any other suitable technique may be used to attach interconnects312-316to batteries104in an interconnect assembly100. Also, the cell retainers108a,108bmay have any suitable numbers and arrangements of recesses1602for batteries104.

FIG.17illustrates an example electric vehicle1700containing one or more interconnect assemblies according to this disclosure. As shown inFIG.17, the electric vehicle1700generally includes a vehicle body1702attached to a vehicle base1704(which is also sometimes referred to as a skateboard). The vehicle body1702in this example takes the form of a passenger van, although vehicle bodies for other types of vehicles (such as sedans, trucks, or other vehicle types) may be used. The vehicle base1704includes many of the components used to move and stop the electric vehicle1700, such as one or more electric motors, brake systems, suspensions, transmissions, and other components.

In this example, the vehicle base1704includes a battery subsystem1706, which includes one or more power supply modules1708. The battery subsystem1706is generally responsible for providing electrical power from the one or more power supply modules1708to other components of the electric vehicle1700during use. The battery subsystem1706is also generally responsible for recharging the one or more power supply modules1708.

Each power supply module1708may represent an instance of the interconnect assembly100, which can be coupled to each other or to other components of the electric vehicle1700using their terminal connectors114a-114b. As shown here, if multiple power supply modules1708are present, one or more power supply modules1708may be coupled in series and/or one or more power supply modules1708may be coupled in parallel. The series and parallel couplings of the power supply modules1708can vary based on, among other things, the electrical voltage and electrical current that can be provided by each power supply module1708and the electrical voltage and electrical current needed by the electric vehicle1700.

AlthoughFIG.17illustrates one example of an electric vehicle1700containing one or more interconnect assemblies, various changes may be made toFIG.17. For example, one or more interconnect assemblies100may be used in any other suitable vehicles. Also, one or more interconnect assemblies may be used to provide electrical power to any other suitable device or system.