Patent Description:
The present disclosure relates generally to the field of batteries and battery modules. More specifically, the present disclosure relates to temperature sensors and methods of integrating temperature sensors in batteries and battery modules.

A vehicle that uses one or more battery systems for providing all or a portion of the motive power for the vehicle can be referred to as an xEV, where the term "xEV" is defined herein to include all of the following vehicles, or any variations or combinations thereof, that use electric power for all or a portion of their vehicular motive force. For example, xEVs include electric vehicles (EVs) that utilize electric power for all motive force. As will be appreciated by those skilled in the art, hybrid electric vehicles (HEVs), also considered xEVs, combine an internal combustion engine propulsion system and a battery-powered electric propulsion system, such as <NUM> volt or <NUM> volt systems. The term HEV may include any variation of a hybrid electric vehicle. For example, full hybrid systems (FHEVs) may provide motive and other electrical power to the vehicle using one or more electric motors, using only an internal combustion engine, or using both. In contrast, mild hybrid systems (MHEVs) disable the internal combustion engine when the vehicle is idling and utilize a battery system to continue powering the air conditioning unit, radio, or other electronics, as well as to restart the engine when propulsion is desired. The mild hybrid system may also apply some level of power assist, during acceleration for example, to supplement the internal combustion engine. Mild hybrids are typically 96V to 130V and recover braking energy through a belt or crank integrated starter generator. Further, a micro-hybrid electric vehicle (mHEV) also uses a "Stop-Start" system similar to the mild hybrids, but the micro-hybrid systems of a mHEV may or may not supply power assist to the internal combustion engine and operates at xEVs as described above may provide a number of advantages as compared to more traditional gas-powered vehicles using only internal combustion engines and traditional electrical systems, which are typically 12V systems powered by a lead acid battery. For example, xEVs may produce fewer undesirable emission products and may exhibit greater fuel efficiency as compared to traditional internal combustion vehicles and, in some cases, such xEVs may eliminate the use of gasoline entirely, as is the case of certain types of EVs or PEVs.

As technology continues to evolve, there is a need to provide improved power sources, particularly battery modules, for such vehicles. For example, in traditional battery module configurations, temperature sensing components may be coupled to a processor of the traditional battery module, such that the processor receives or determines data indicative of a temperature of various portions of the traditional battery module. Unfortunately, integrating traditional temperature sensing components in traditional battery modules may be cumbersome and expensive, and may lead to undesirable affects, such as inaccurate temperature measurements. Accordingly, improved temperature sensors and integration features are desired.

The document <CIT> relates to a power battery module with a battery collection system.

The document <CIT> relates to a battery module that comprises a battery pack having at least one single battery and at least one power splicer, and a sampling module having a flexible circuit board. At least one voltage sampling terminal and temperature sensors are disposed on the flexible circuit board, the temperature sensor being connected with the power splicer, the voltage sampling terminal being electrically connected with the power splicer.

The document <CIT> relates to a storage battery assembly for vehicles that includes a plurality of battery cells. Each battery cell includes a closed housing and at least one terminal extending from the housing. Conductive bars are mounted on dedicated terminals. The conductive bars electrically connect the battery cells.

The document <CIT> relates to a cell assembly that comprises a cell frame into which a thermal plate is integrated.

The document <CIT> relates to a battery module for use in a vehicle. The battery module includes a housing, a plurality of battery cells disposed within the housing, and solid state pre-charge control circuitry that precharges a direct current bus that may be coupled between the battery module and an electronic component of the vehicle.

The document <CIT> relates to a battery module having electrochemical cells and a bus bar carrier. The bus bar carrier includes a finger having a first surface, a second surface opposite to the first surface and configured to be disposed proximate to a first electrochemical cell of the plurality of electrochemical cells.

The document <CIT> relates to a battery module that includes electrochemical cells having an electrochemical cell with a terminal end. The battery module also includes a bus bar carrier configured to interface bus bars with terminals of the electrochemical cells and having a window.

The present invention relates to a bus bar assembly according to independent claim <NUM>, i.e. a bus bar assembly for a battery module having a plurality of electrochemical cells. Further developments of the bus bar assembly are provided in sub-claims <NUM> to <NUM>. The present invention further relates to a battery module according to claim <NUM> and to a method of making a battery module according to claim <NUM>.

In an embodiment, disclosed is a bus bar assembly for a battery module having a plurality of electrochemical cells. The bus bar assembly comprising a bus bar carrier configured to receive bus bars to interface with terminals of the plurality of electrochemical cells, a flex circuit disposed on the bus bar carrier, and a temperature sensor welding tab comprising a circuit engagement region secured to the flex circuit and a welding region to be welded to an end of an electrochemical cell.

In another embodiment, disclosed is a battery module. The battery module includes a housing, a plurality of electrochemical cells disposed in the housing, the plurality of electrical chemical cells including an electrochemical cell having a terminal end and a terminal of the terminal end, and the bus bar assembly, wherein the temperature sensor welding tab is welded to the terminal end of the electrochemical cell.

In yet another embodiment, disclosed is a method of making a battery module including a housing. The method includes placing a plurality of electrochemical cells in the housing, providing a bus bar assembly including a bus bar carrier and a flex circuit disposed on the bus bar carrier, soldering a circuit engagement region of a temperature sensor welding tab to a flexible extension of the flex circuit, placing the bus bar assembly adjacent to the plurality of electrochemical cells, flexing the flexible extension toward the electrochemical cells such that a temperature sensor of the flex circuit is in close proximity to a terminal end of an electrochemical cell of the plurality of electrochemical cells, and welding a welding region of the temperature sensor welding tab to the terminal end of the electrochemical cell.

These and other features and advantages of devices, systems, and methods according to this invention are described in, or are apparent from, the following detailed descriptions of various examples of embodiments.

One or more examples of embodiments of the apparatus and methods according to this invention will be described in detail, with reference to the following figures, wherein:.

In certain instances, details that are not necessary to the understanding of the invention or render other details difficult to perceive may have been omitted. It should be understood, of course, that the invention is not necessarily limited to the particular embodiments illustrated herein.

The battery systems described herein may be used to provide power to various types of electric vehicles (xEVs) and other high voltage energy storage/expending applications (e.g., electrical grid power storage systems). Such battery systems may include one or more battery modules, each battery module having a number of prismatic battery cells (e.g., lithium-ion (Li-ion) electrochemical cells) arranged to provide particular voltages and/or currents useful to power, for example, one or more components of an xEV.

Certain battery modules may include temperature sensing features that allow for temperature sensing of one battery cell, or a group of battery cells, within the module. Generally, the temperature sensors relay signals to a control module of the battery module to allow the control module to supervise temperature management of the battery cells. One challenge associated with temperature sensing of battery cells is providing a sufficient surface area of interface between a temperature sensor and a battery cell housing ("can"). Indeed, certain battery cell housing shapes present bigger challenges than others. For instance, flatter battery cells, such as pouch or prismatic battery cells, generally do not have excess surface area for the interface. Thus, sensing maximum cell temperature and reporting it to a battery management system is a challenge with the flat cell can interfaces. It is now recognized that a robust interface method is needed to pass environmental mechanical tests such as vibration and shock tests.

Certain of the configurations described herein use a flexible circuit as a voltage and temperature sensing component. In conventional techniques, for instance those associated with use of traditional wire harnesses, thermistors, a particular type of temperature sensor, are potted to a ring terminal that is either fastened or welded to cell terminals or cell cans. However, because flexible circuits use traces and not wire conductors, potting a copper trace is not feasible and would be mechanically weak.

One possible method would be to use a pressure sensitive adhesive (PSA) to attach a thermistor tab (which contacts a battery cell) to a flexible circuit. However, the PSA may provide an insufficient bond under certain temperature conditions (e.g., higher operating temperatures) due to small available surface contact when subjected to vibration and shock testing.

In one or more implementations, a mechanical joint is formed using solder to anchor the thermistor tab to the flexible circuit. The thermistor tab is designed to have a geometry that facilitates such an attachment. For instance, the thermistor tab geometry may be designed with two bends that each feed through two cutouts in the flexible circuit. The two cutouts are surrounded by conductive pads that are to be generated during the etching process of the flexible circuit. Before installing the thermistor tab, all the conductive pads are masked with solder paste in preparation for a reflow process, which is a particular type of solder process. When the flexible circuit assembly is reflowed, a mechanical joint (which is electrically isolated) is created between solder and the thermistor tab.

To help illustrate, <FIG> is a perspective view of a vehicle <NUM>, which may utilize a regenerative braking system. Although the following discussion is presented in relation to vehicles with regenerative braking systems, the techniques described herein are adaptable to other vehicles that capture/store electrical energy with a battery, which may include electric-powered and gas-powered vehicles.

As discussed above, it would be desirable for a battery system <NUM> to be largely compatible with traditional vehicle designs. Accordingly, the battery system <NUM> may be placed in a location in the vehicle <NUM> that would have housed a traditional battery system. For example, as illustrated, the vehicle <NUM> may include the battery system <NUM> positioned similarly to a lead-acid battery of a typical combustion-engine vehicle (e.g., under the hood of the vehicle <NUM>). Furthermore, as will be described in more detail below, the battery system <NUM> may be positioned to facilitate managing temperature of the battery system <NUM>. For example, in some constructions, positioning a battery system <NUM> under the hood of the vehicle <NUM> may enable an air duct to channel airflow over the battery system <NUM> and cool the battery system <NUM>.

In other words, the battery system <NUM> may supply power to components of the vehicle's electrical system, which may include radiator cooling fans, climate control systems, electric power steering systems, active suspension systems, auto park systems, electric oil pumps, electric super/turbochargers, electric water pumps, heated windscreen/defrosters, window lift motors, vanity lights, tire pressure monitoring systems, sunroof motor controls, power seats, alarm systems, infotainment systems, navigation features, lane departure warning systems, electric parking brakes, external lights, or any combination thereof. Illustratively, in the depicted construction, the energy storage component <NUM> supplies power to the vehicle console <NUM> and the ignition system <NUM>, which may be used to start (e.g., crank) the internal combustion engine <NUM>.

Additionally, the energy storage component <NUM> may capture electrical energy generated by the alternator <NUM> and/or the electric motor <NUM>. In some constructions, the alternator <NUM> may generate electrical energy while the internal combustion engine <NUM> is running. More specifically, the alternator <NUM> may convert the mechanical energy produced by the rotation of the internal combustion engine <NUM> into electrical energy. Additionally or alternatively, when the vehicle <NUM> includes an electric motor <NUM>, the electric motor <NUM> may generate electrical energy by converting mechanical energy produced by the movement of the vehicle <NUM> (e.g., rotation of the wheels) into electrical energy. Thus, in some construction, the energy storage component <NUM> may capture electrical energy generated by the alternator <NUM> and/or the electric motor <NUM> during regenerative braking. As such, the alternator <NUM> and/or the electric motor <NUM> are generally referred to herein as a regenerative braking system.

To facilitate capturing and supplying electric energy, the energy storage component <NUM> may be electrically coupled to the vehicle's electric system via a bus <NUM>. For example, the bus <NUM> may enable the energy storage component <NUM> to receive electrical energy generated by the alternator <NUM> and/or the electric motor <NUM>. Additionally, the bus <NUM> may enable the energy storage component <NUM> to output electrical energy to the ignition system <NUM> and/or the vehicle console <NUM>. Accordingly, when a <NUM>-volt battery system <NUM> is used, the bus <NUM> may carry electrical power typically between <NUM>-<NUM> volts.

Additionally, as depicted, the energy storage component <NUM> may include multiple battery modules. For example, in the depicted construction, the energy storage component <NUM> includes a lithium ion (e.g., a first) battery module <NUM> and a lead-acid (e.g., a second) battery module <NUM>, which each includes one or more battery cells. In other constructions, the energy storage component <NUM> may include any number of battery modules. Additionally, although the lithium ion battery module <NUM> and lead-acid battery module <NUM> are depicted adjacent to one another, they may be positioned in different areas around the vehicle. For example, the lead-acid battery module <NUM> may be positioned in or about the interior of the vehicle <NUM> while the lithium ion battery module <NUM> may be positioned under the hood of the vehicle <NUM>.

In some constructions, the energy storage component <NUM> may include multiple battery modules to utilize multiple different battery chemistries. For example, when the lithium ion battery module <NUM> is used, performance of the battery system <NUM> may be improved since the lithium ion battery chemistry generally has a higher coulombic efficiency and/or a higher power charge acceptance rate (e.g., higher maximum charge current or charge voltage) than the lead-acid battery chemistry. As such, the capture, storage, and/or distribution efficiency of the battery system <NUM> may be improved.

To facilitate controlling the capturing and storing of electrical energy, the battery system <NUM> may additionally include a control module <NUM>. More specifically, the control module <NUM> may control operations of components in the battery system <NUM>, such as relays (e.g., switches) within energy storage component <NUM>, the alternator <NUM>, and/or the electric motor <NUM>. For example, the control module <NUM> may regulate an amount of electrical energy captured/supplied by each battery module <NUM> or <NUM> (e.g., to de-rate and re-rate the battery system <NUM>), perform load balancing between the battery modules <NUM> and <NUM>, determine a state of charge of each battery module <NUM> or <NUM>, determine temperature of each battery module <NUM> or <NUM>, control voltage output by the alternator <NUM> and/or the electric motor <NUM>, and the like.

Accordingly, the control unit <NUM> may include one or more processor <NUM> and one or more memory <NUM>. More specifically, the one or more processor <NUM> may include one or more application specific integrated circuits (ASICs), one or more field programmable gate arrays (FPGAs), one or more general purpose processors, or any combination thereof. Additionally, the one or more memory <NUM> may include volatile memory, such as random access memory (RAM), and/or nonvolatile memory, such as read-only memory (ROM), optical drives, hard disc drives, or solid-state drives. In some constructions, the control unit <NUM> may include portions of a vehicle control unit (VCU) and/or a separate battery control module.

<FIG> is a partial exploded, perspective view of a battery module <NUM> for use in the vehicle <NUM> of <FIG>. Before proceeding, it should be noted that the battery module <NUM> may be used in other electrical environments and is not limited to the vehicle <NUM> of <FIG>. For simplicity, not all components of the battery module <NUM> are illustrated. The battery module <NUM> (e.g., lithium-ion (Li-ion) battery module) includes a housing <NUM> (e.g., plastic housing), a bus bar carrier <NUM>, a flex circuit <NUM>, and a cover <NUM>. A plurality of electrochemical cells <NUM> (e.g., Li-ion electrochemical cells), otherwise referred to as battery cells when enclosed by an individual battery cell housing, are disposed within the housing <NUM>. In certain constructions, the battery module <NUM> may include any number of electrochemical cells <NUM> (e.g., <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or more electrochemical cells), any type of electrochemical cell <NUM> (e.g., Li-ion, lithium polymer, lead-acid, nickel cadmium, or nickel metal hydride, prismatic, and/or cylindrical), and any arrangement of the electrochemical cells <NUM> (e.g., stacked, separated, or compartmentalized).

The housing <NUM> includes an opening <NUM> on one side (upper side or face) to receive the electrochemical cells <NUM>. The bus bar carrier <NUM> may be disposed within the opening <NUM> and above the electrochemical cells <NUM>, and may include bus bars disposed thereon configured to interface with terminals <NUM> extending from terminal ends <NUM> of the electrochemical cells <NUM>. That is, the bus bars may be disposed in locations of the bus bar carrier <NUM> suitable for coupling the bus bars to the terminals <NUM> of the electrochemical cells <NUM>. The bus bar carrier <NUM> may also include the flex circuit <NUM> disposed thereon. For example, the flex circuit <NUM> may be disposed on an upper side <NUM> of the bus bar carrier <NUM> opposing an underside <NUM> of the bus bar carrier <NUM>. The flex circuit <NUM> in the illustrated construction is coupled to the upper side <NUM> of the bus bar carrier <NUM>. The flex circuit <NUM> may include a flexible material, such as a polyimide material, within which (and from which) electrical components extend. The electrical components of the flex circuit <NUM> may be configured to interface with the bus bars and/or with the terminal ends <NUM> of the electrochemical cells <NUM>. For example, as will be appreciated in view of further discussion below, the flex circuit <NUM> may include voltage sensing tabs configured to contact bus bars of the battery module <NUM>, and temperature sensor welding tabs <NUM> (<FIG>) configured to contact the terminal ends <NUM> of certain ones of the electrochemical cells <NUM>. Each temperature sensor welding tab may include a metal material, such as aluminum, and may be configured to be welded (e.g., from overhead) to the terminal end <NUM> of one of the electrochemical cells <NUM>. The flex circuit <NUM> may also include electrical contacts <NUM> extending toward other features disposed in the housing <NUM>, such as a processor of the battery module <NUM> or an electrical path to the processor.

As set forth above and described in further detailed below, the voltage sensing tabs and the temperature sensor welding tabs <NUM> may be strategically positioned on the flex circuit <NUM>, and the flex circuit <NUM> may be strategically positioned on the bus bar carrier <NUM>, to enable coupling of the voltage sensing tabs and the temperature sensor welding tabs <NUM> of the flex circuit <NUM> with the appropriate features of the battery module <NUM>. Aspects of the temperature sensor welding tabs <NUM> will be described in detail below with reference to later drawings.

<FIG> is a perspective view of the bus bar carrier <NUM> having the flex circuit <NUM>. As previously described, the flex circuit <NUM> may include a thin layer of flexible and electrically insulative material, such as polyimide. The flex circuit <NUM> may include various electrical components disposed in and/or extending from the polyimide material of the flex circuit <NUM>. For example, electrical conductors (e.g., traces) may be embedded within and/or printed on the polyimide material of the flex circuit <NUM>, and may extend between various electrical components of the flex circuit <NUM>. In the illustrated construction, the flex circuit <NUM> includes, for example, two temperature sensor welding tabs <NUM> extending from edges of the flex circuit <NUM>, among other electrical components. In particular and as shown in further detail in <FIG>, the temperature sensor welding tabs <NUM> are securely fastened to the flex circuit <NUM> by way of at least one bond formed by reflow soldering.

Referring to <FIG> and <FIG>, the temperature sensor welding tabs <NUM> are disposed on portions of the flex circuit <NUM> that, when the flex circuit <NUM> is disposed on the bus bar carrier <NUM>, cause the temperature sensor welding tabs <NUM> to extend through openings, or windows <NUM>, in the bus bar carrier <NUM>. The windows <NUM> may extend, for example, from the upper side <NUM> of the bus bar carrier <NUM> to the underside <NUM> of the bus bar carrier <NUM>. That is, the windows <NUM> extend entirely through a thickness of the bus bar carrier <NUM>. The windows <NUM> enable the temperature sensor welding tabs <NUM> to extend from the flex circuit <NUM> disposed on the upper side <NUM> of the bus bar carrier <NUM> into contact with features (e.g., terminal ends of electrochemical cells) disposed adjacent (e.g., under) the underside <NUM> of the bus bar carrier <NUM>. The windows <NUM> also enable an unobstructed view of the temperature sensor welding tabs <NUM> from above the bus bar carrier <NUM>. For example, <FIG> is a top view of the bus bar carrier <NUM> and the flex circuit <NUM> of <FIG>. As shown, each temperature sensor welding tab <NUM> includes a welding region <NUM> that is unobstructed from view. The welding region <NUM> may be welded or otherwise adhered to, for example, a terminal end of an electrochemical cell disposed underneath the bus bar carrier <NUM>.

<FIG> and <FIG> are perspective views of a portion of the bus bar carrier <NUM> and flex circuit <NUM> of <FIG>. For example, <FIG> is an overhead perspective view of the portion of the bus bar carrier <NUM> and the flex circuit <NUM>, and <FIG> is a bottom perspective view of the portion of the bus bar carrier <NUM> and the flex circuit <NUM>. In <FIG>, the flex circuit <NUM> is illustrated as disposed on the upper side <NUM> of the bus bar carrier <NUM>. The bus bar carrier <NUM> includes the window <NUM> through which the temperature sensor welding tab <NUM> extends. As shown in <FIG>, the flex circuit <NUM> includes a notch <NUM> between two adjacent extensions <NUM>, <NUM> of the flex circuit <NUM>, where the temperature sensor welding tab <NUM> is disposed on the first extension <NUM> of the two extensions <NUM>, <NUM>. A notch <NUM> may also be disposed on an opposing side of the first extension <NUM>. That is, the first extension <NUM> may be defined by the two notches <NUM>, <NUM>, and may include a rectangular shape or other suitable shape.

By disposing the temperature sensor welding tab <NUM> on the first extension <NUM>, the first extension <NUM> may flex downwardly when the temperature sensor welding tab <NUM> is welded or otherwise adhered to the terminal end of the electrochemical cell. Thus, as set forth above, the temperature sensor welding tab <NUM> is reliably secured to the flex circuit <NUM>. For example, as shown, the temperature sensor welding tab <NUM> includes a circuit engagement region <NUM>, the welding region <NUM>, and a transverse region <NUM> extending transversely between the circuit engagement region <NUM> and the welding region <NUM>. That is, in the illustrated construction the temperature sensor welding tab <NUM> includes a bent plate, where the transverse region <NUM> is bent relative to the circuit engagement region <NUM>, and the welding region <NUM> is bent relative to the transverse region <NUM>. In other words, the transverse region <NUM> extends at a non-right angle relative to the circuit engagement region <NUM> and the welding region <NUM> to enable passage of the temperature sensor welding tab <NUM> from the flex circuit <NUM> on the upper side <NUM> of the bus bar carrier <NUM>, through the window <NUM>, and adjacent the underside <NUM> (see <FIG>) of the bus bar carrier <NUM>. Further, the bend of the temperature sensor welding tab <NUM> (e.g., between the transverse region <NUM> and the circuit engagement region <NUM>, and between the transverse region <NUM> and the welding region <NUM>) enforces a gap between the terminal end of the electrochemical cell and other components (e.g., thermistors) of, or on, the flex circuit <NUM>.

<FIG>, the temperature sensor welding tab <NUM> is illustrated as extending through the window <NUM>, and being disposed adjacent the underside <NUM> of the bus bar carrier <NUM>. That is, the welding region <NUM> is disposed adjacent the underside <NUM> of the bus bar carrier <NUM>, and may be configured to be welded to the terminal end of an electrochemical cell. Further, in <FIG>, thermistors <NUM> are disposed on the flex circuit <NUM> adjacent to the temperature sensor welding tab <NUM>. For example, the thermistors <NUM> are disposed on an underside <NUM> of the first extension <NUM> of the flex circuit <NUM>. The temperature sensor welding tab <NUM> may be used, via the coupling (e.g., weld) to the terminal end of the electrochemical cell, to bring the thermistors <NUM> in close proximity to the terminal end of the electrochemical cell. For example, when the temperature sensor welding tab <NUM> is coupled to the terminal end of the electrochemical cell, the connection may cause the first extension <NUM> of the flex circuit <NUM> to be pulled downwardly, and the thermistors <NUM> may be disposed on the underside <NUM> of the first extension <NUM> of the flex circuit <NUM>. Thus, the thermistors <NUM> may be pulled toward, or held in close proximity to, the terminal end of the electrochemical cell via the coupling of the temperature sensor welding tab <NUM> to the terminal end of the electrochemical cell.

In some constructions, the thermistors <NUM> may be decoupled from the temperature sensor welding tab <NUM>, but disposed in close proximity to the temperature sensor welding tab <NUM> (i.e., on the underside <NUM> of the first extension <NUM> of the flex circuit <NUM>) to enable the above-described effects. In other construction, the thermistors <NUM> may be electrically coupled to the temperature sensor welding tab <NUM>. Further, the thermistors <NUM> may be electrically coupled to electrical conductors (e.g., traces) encapsulated by the polyimide material of the flex circuit <NUM>, and/or running along an underside of the flex circuit <NUM> between the flex circuit <NUM> and the bus bar carrier <NUM>. The electrical conductors may then couple to electrical contacts <NUM> (see <FIG> and <FIG>), which may be coupled to a processor or other feature of a printed circuit board or battery module control and/or monitoring assembly.

The manner in which a temperature sensor welding tab <NUM> may be coupled to the flex circuit <NUM> may be further appreciated with reference to <FIG>, which depict expanded views of one of a temperature sensor welding tabs <NUM> in relation to the flex circuit <NUM>. In particular, <FIG> depicts an expanded perspective view of an upper side <NUM> of the flex circuit <NUM> (i.e., a side that faces away from the electrochemical cells <NUM>). In the illustrated construction, the circuit engagement region <NUM> is disposed against the upper side <NUM> of the flex circuit <NUM>. The temperature sensor welding tab <NUM> includes a first tab <NUM> and a second tab <NUM> that extend from the circuit engagement region <NUM>, for example from opposite sides of the circuit engagement region <NUM>. That is, the first tab <NUM> and the second tab <NUM> may protrude in opposite directions from the circuit engagement region <NUM>. The first tab <NUM> and the second tab <NUM> are also angled with respect to the plane of the circuit engagement region <NUM> and the flex circuit <NUM>. That is, the first tab <NUM> and the second tab <NUM> each protrude in a first direction away from the circuit engagement region <NUM>, and then protrude in a second, crosswise direction with respect to the plane of the circuit engagement region <NUM> and the plane of the flex circuit <NUM>. This second, crosswise direction of extension may be produced by a bend, curvature, etc., of the first tab <NUM> and the second tab <NUM>.

The bends of the first tab <NUM> and the second tab <NUM> allow them to protrude through the flex circuit <NUM> at a first via <NUM> and a second via <NUM>, respectively. The first tab <NUM> and the second tab <NUM> may have any suitable geometry and any suitable dimension, provided that at least some of the techniques presently described for securement with the flex circuit <NUM> can be performed.

The first via <NUM> and the second via <NUM> may have any suitable shape and size to accommodate protrusion of the first tab <NUM> and the second tab <NUM> through the flex circuit <NUM> from the upper side <NUM> to the underside <NUM>, as shown in <FIG>. In accordance with certain constructions, the first via <NUM> and the second via <NUM> may have a perimeter shape and size that is just slightly larger than the cross-sectional size of the first tab <NUM> and the second tab <NUM>. For example, the first via <NUM> and the second via <NUM> may be sized to allow a robotic placement system to position the flex circuit <NUM> atop the temperature sensor welding tab <NUM> in a manner that allows the first tab <NUM> and the second tab <NUM> to extend through the flex circuit <NUM>, without additional operations.

As shown in <FIG>, the first tab <NUM> and the second tab <NUM> may be secured to the flex circuit <NUM> using a first solder pad <NUM> and a second solder pad <NUM>, respectively. In particular, a paste containing solder may be positioned on the flex circuit <NUM>. Once the flex circuit <NUM> is placed atop the temperature sensor welding tab <NUM> causing the first and second tabs <NUM>, <NUM> to protrude through the flex circuit <NUM>, the paste is heated by an amount sufficient to cause the solder to flow. Once the solder cools, the first and second tabs <NUM>, <NUM> are secured to the flex circuit <NUM> by the solder. Such a process may be referred to as a reflow process of soldering. In this respect, the reflow process is used to secure the temperature sensor welding tab <NUM> to the flex circuit <NUM>.

In certain construction, the reflow process may be performed in a manner that secures several features to the flex circuit <NUM> at once. For example, referring to the construction illustrated in <FIG>, the reflow process may be used to secure the first and second tabs <NUM>, <NUM>, the temperature sensor <NUM> (a thermistor) and a capacitor <NUM> to the flex circuit <NUM>. Once such features are secured to the flex circuit <NUM>, the temperature sensor welding tab <NUM> may be considered ready for attachment to one of the electrochemical cells <NUM>. Attachment of features in this order may facilitate assembly and manufacturing. However, the present disclosure is not necessarily limited to this order of operations.

<FIG> is a schematic cross-sectional side view of a construction of a coupling between the terminal end <NUM> of an electrochemical cell <NUM> and the temperature sensor welding tab <NUM> of the present disclosure. As previously described, the temperature sensor welding tab <NUM> may include the circuit engagement region <NUM>, the welding region <NUM>, and the transverse region <NUM> extending between the circuit engagement region <NUM> and the welding region <NUM>. The transverse region <NUM> may be bent to form an angle with the welding region <NUM>, and the circuit engagement region <NUM> may be bent relative to the transverse region <NUM> to form another angle with the transverse region. By including the transverse region <NUM> extending at angles relative to the welding region <NUM> and the circuit engagement region <NUM>, the welding region <NUM> may fall flat on the terminal end <NUM> of the electrochemical cell <NUM>. The welding region <NUM> may be coupled to the terminal end <NUM> of the electrochemical cell <NUM> such that at least the transverse region <NUM> of the temperature sensor welding tab <NUM> is disposed in the window <NUM> of the bus bar carrier <NUM>. As shown, a portion (e.g., the first segment <NUM>) of the polyimide material of the flex circuit <NUM> may also extend into (e.g., overlap with) the window <NUM> of the bus bar carrier <NUM>, and the thermistors <NUM> may be disposed on the first segment <NUM> of the polyimide material of the flex circuit <NUM>. Thus, the temperature sensor welding tab <NUM>, when coupled to the terminal end <NUM> of the electrochemical cell <NUM>, may cause the first segment <NUM> of the polyimide material of the flex circuit <NUM>, and the thermistors <NUM> coupled to the first segment <NUM>, to be drawn toward the terminal end <NUM> of the electrochemical cell <NUM>. However, in other construction, the welding region <NUM> may fall flat against the terminal end <NUM> of the electrochemical cell <NUM> without substantial bending of the first segment <NUM> of the polyimide material of the flex circuit <NUM>.

Further, the bend of the temperature sensor welding tab <NUM> (e.g., between the transverse region <NUM> and the circuit engagement region <NUM>, and between the transverse region <NUM> and the welding region <NUM>) enforces a gap between the terminal end <NUM> of the electrochemical cell <NUM> and other components (e.g., thermistors <NUM>) of, or on, the flex circuit <NUM>. The gap blocks an interference of the electrochemical cell <NUM> upon the thermistors <NUM> and/or other components.

The disclosed features of the bus bar carrier <NUM>, the flex circuit <NUM>, the temperature sensor welding tabs <NUM>, and the thermistors <NUM> may enable improved assembly of the battery module, may reduce a cost of the battery module, and may improve temperature measurements determined by the battery module.

As utilized herein, the terms "approximately," "about," "substantially," and similar terms 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. It should be understood by those of skill in the art who review this disclosure that these terms are intended to allow a description of certain features described and claimed without restricting the scope of these features to the precise numerical ranges provided. 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 invention as recited in the appended claims.

It should be noted that references to relative positions (e.g., "top" and "bottom") in this description are merely used to identify various elements as are oriented in the Figures. It should be recognized that the orientation of particular components may vary greatly depending on the application in which they are used.

For the purpose of this disclosure, the term "coupled" means the joining of two members directly or indirectly to one another. Such joining may be stationary in nature or moveable in nature. Such joining may be achieved with the two members or the two members and any additional intermediate members being integrally formed as a single unitary body with one another or with the two members or the two members and any additional intermediate members being attached to one another. Such joining may be permanent in nature or may be removable or releasable in nature.

It is also important to note that the construction and arrangement of the system, methods, and devices as shown in the various examples of embodiments is illustrative only. Although only a few embodiments have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter recited. For example, elements shown as integrally formed may be constructed of multiple parts or elements show as multiple parts may be integrally formed, the operation of the interfaces may be reversed or otherwise varied, the length or width of the structures and/or members or connector or other elements of the system may be varied, the nature or number of adjustment positions provided between the elements may be varied (e.g. by variations in the number of engagement slots or size of the engagement slots or type of engagement). The order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments.

While this invention has been described in conjunction with the examples of embodiments outlined above, various alternatives, modifications, variations, improvements and/or substantial equivalents, whether known or that are or may be presently foreseen, may become apparent to those having at least ordinary skill in the art. Accordingly, the examples of embodiments of the invention, as set forth above, are intended to be illustrative, not limiting.

Claim 1:
A bus bar assembly for a battery module (<NUM>) having a plurality of electrochemical cells (<NUM>), the bus bar assembly comprising:
- a bus bar carrier (<NUM>) configured to receive bus bars to interface with terminals (<NUM>) of the plurality of electrochemical cells (<NUM>);
- a flex circuit (<NUM>) disposed on the bus bar carrier (<NUM>); and
- a temperature sensor welding tab (<NUM>) comprising a circuit engagement region (<NUM>) secured to the flex circuit (<NUM>) and a welding region (<NUM>) to be welded to an end of an electrochemical cell (<NUM>),
wherein the circuit engagement region (<NUM>) of the temperature sensor welding tab (<NUM>) comprises a first tab (<NUM>) and a second tab (<NUM>) each protruding in a first direction away from the circuit engagement region (<NUM>), each of the first and second tabs (<NUM>, <NUM>) comprising a bend that causes the first and second tabs (<NUM>, <NUM>) to protrude in a second direction through vias (<NUM>, <NUM>) of the flex circuit (<NUM>).