Battery assemblies, motor vehicles, and methods for fastening battery components using fast-curing adhesives

Abstract

A battery arrangement (100), comprising: a battery housing (104); a plurality of battery cells (102) arranged in the battery housing (104); a first and a second shear plate (120, 122) which are attached to opposite first and second housing sides of the battery housing (104) and enclose the battery cells (102) between them; a first adhesive layer (230) arranged between the battery cells (102) and the first shear plate (120), wherein the first adhesive layer (230) comprises a first adhesive with a first chemical composition and a first curing time, and a second adhesive with a second chemical composition that differs from the first chemical composition and has a second curing time that is shorter than the first curing time; and a second adhesive layer (232) arranged between the battery cells (102) and the first or second shear plate (120, 122), spaced apart from the first adhesive layer (230) and containing the first and second adhesive; wherein the first and second adhesive layers (230, 232) each have a central region (240A) and a first and a second side region (242A, 242B) arranged on opposite first and second lateral sides of the central region (240A), wherein the central region (240A) is defined by the first adhesive and the first and second side regions (242A, 242B) are defined by the second adhesive.

Description

Technical field

[0001] The present disclosure relates generally to electrochemical devices for generating electrical energy. In particular, aspects of this disclosure relate to systems, methods, and devices for securely fastening battery components in battery casings. introduction

[0002] Today's production vehicles, such as modern automobiles, are originally equipped with a powertrain that propels the vehicle and supplies its onboard electronics. In motor vehicles, for example, the powertrain typically consists of a drive motor that transmits the drive torque to the vehicle's drive system (e.g., differential, axles, camshafts, wheels, etc.) via an automatic or manual transmission. Historically, motor vehicles were powered by internal combustion engines (ICEs) because they were readily available, relatively inexpensive, lightweight, and highly efficient. These engines include compression-ignition (CI) diesel engines, spark-ignition (SI) gasoline engines, two-, four-, and six-stroke engines, and rotary engines, to name just a few.Hybrid electric and fully electric vehicles (collectively referred to as "electrically powered vehicles"), on the other hand, use alternative energy sources to power the vehicle, thus minimizing or eliminating dependence on a fossil fuel-based engine for traction.

[0003] A fully electric vehicle (FEV) – colloquially referred to as an "electric car" – is an electric vehicle configuration in which the internal combustion engine and its associated peripheral drive system components are completely eliminated, and instead a rechargeable energy storage system (RESS) and a traction motor are used to propel the vehicle. The engine assembly, fuel supply, and exhaust system of a combustion engine vehicle are replaced in a battery-powered FEV by one or more traction motors, rechargeable battery cells, and cooling and charging equipment. Hybrid electric vehicle (HEV) powertrains, on the other hand, use multiple traction sources to propel the vehicle, most often an internal combustion engine in conjunction with a battery- or fuel cell-powered traction motor.Since electric vehicles are able to draw their power from sources other than the engine, HEV engines can be switched off completely or partially while the vehicle is driven by the electric motor(s).

[0004] High-voltage electrical systems regulate the transfer of power between the traction motors and the rechargeable battery packs that supply the energy required to operate many hybrid-electric and all-electric powertrains. To provide the power capacity and energy density needed to propel a vehicle at the desired speed and over the desired range, modern traction battery packs combine multiple battery cells (e.g., 8-16+ cells / stack) into individual battery modules (e.g., 10-40+ modules / pack) that are electrically connected in series or parallel and mounted on the vehicle chassis, for example, by a battery pack housing or a carrier plate.On the battery side of the high-voltage network, there is a DC-DC converter electrically connected to the traction battery(ies) to boost the voltage supply to a main DC bus and a DC inverter module (PIM). A high-frequency capacitor is located between the positive and negative terminals of the main DC bus to provide electrical stability and store additional electrical energy. A dedicated electronic battery control module (EBCM), in conjunction with a powertrain control module (PCM) and the power electronics of each motor, controls the operation of the battery pack(s) and the traction motor(s).

[0005] There are four main types of batteries used in modern electric vehicles: lithium-ion batteries, nickel-metal hydride batteries, ultracapacitor batteries, and lead-acid batteries. As with lithium-ion batteries, lithium-metal and lithium-ion batteries (secondary batteries) make up the majority of commercial lithium-ion battery configurations in motor vehicles due to their higher stability, energy density, and rechargeability. A standard lithium-ion cell typically consists of an ion-conducting electrolyte material, at least one pair of working electrodes, and a permeable separator, all enclosed in an electrically insulated package, such as a cell bag, cylindrical can, or prismatic tray. One electrode serves as the positive (“cathode”) electrode, and the other serves as the negative (“anode”) electrode during cell discharge.Rechargeable lithium-ion batteries function by reversibly passing lithium ions through the separator and between the negative and positive electrodes. During battery pack assembly, individual cells are securely fixed to minimize vibration and rattling noises, extending cell lifespan during pack use. Rigid cell mounting typically employs mechanical fasteners or cell holders to keep cells in place during assembly, facilitating cell alignment and installation within the pack housing, as well as electrical connection.

[0006] DE 10 2021 122 729 A1 describes a battery system with battery cells arranged and bonded to a carrier. One or more side walls are bonded to the battery cells for support, and a current collector assembly is also bonded to one axial side of the battery cells. One or more dividers may be included to maintain electrical insulation between the parallel-connected battery cell groups. The other axial side of the battery cells is bonded to a cooling plate. A similar structure is bonded to the other side of the cooling plate to form a compact battery system. Shear walls, busbars, terminal busbars, and an insulating bracket with a mounted electronic control unit are bonded to the assembly to form the battery system. Each adhesive or adhesive type may have specific criteria and requirements, such as…Strength, thermal conductivity, electronic conductivity, curing requirements, or a combination thereof. Description of the invention

[0007] This paper presents battery assemblies that utilize adhesives to fasten battery components, methods for manufacturing and using such battery assemblies, and electrically powered vehicles with battery packs where the battery cells are fixed within a package housing using both fast- and slow-curing adhesives. One example is a rechargeable traction battery pack containing an array of cylindrical lithium-class battery cells. The cell array can be embedded between an electrical interconnect board (ICB) and a cell carrier plate, which in turn are sandwiched between an upper and a lower shear plate.During package assembly, a complex pattern of adhesives is applied, using a fast-curing (secondary) adhesive in conjunction with a slow-curing (primary) adhesive to facilitate cell alignment, fixation, and bonding. The primary adhesive is often selected to meet system structural integrity requirements and noise, vibration, and harshness (NVH) limits; however, the primary adhesive's curing time can significantly exceed cycle times at any dispensing station. Instead of using expensive and time-consuming fixtures or mechanical fixings to secure the cells, tray, and ICB within the packaging housing, a fast-curing adhesive is used to fix these components while the primary adhesive cures.

[0008] To ensure that the battery components are securely fastened during the package manufacturing process, the fast-curing adhesive can be applied in a predefined adhesive pattern to a predetermined optimal surface area of ​​the carrier board and the ICB. The adhesive pattern and surface area can be designed to determine an optimal ratio of primary to secondary adhesive. Furthermore, the optimal ratio and individual chemical compositions of the adhesives can be selected based on a predefined minimum bond strength, the geometry of the battery system, and the manufacturing processes that occur during the curing of the primary adhesive. Both the primary and secondary adhesives can be applied to the cells, cell carrier, ICB, etc., only at selected locations and in predefined patterns.The fast-curing adhesive can be applied after and in direct physical contact with the primary adhesive. Once the battery cells are placed on the substrate and the fast-curing adhesive has reached its green strength, further manufacturing processes are carried out while the primary adhesive cures.

[0009] The advantages of at least some disclosed concepts include battery assembly architectures that utilize fast-curing adhesives to bond battery components, thus enabling the use of larger quantities of primary adhesives with longer processing times for pack assembly. Further advantages include the ability to select the primary structural adhesive for the battery pack based on the adhesive's performance characteristics rather than its handling and curing times. These characteristics can also help minimize curing wait times, thereby reducing manufacturing times, and eliminate the need for cell fixtures, thus lowering tooling and fixture costs.

[0010] Aspects of this disclosure relate to multilayer, multi-layer adhesive compositions for fastening battery components of battery assemblies, including both automotive and non-automotive applications. According to the invention, a battery assembly is presented, which may be a rechargeable battery pack for supplying an electrified powertrain of an electrically powered motor vehicle. The battery assembly comprises a protective outer housing that encloses a plurality of battery cells, for example, a rectangular array of cylindrical lithium-class (secondary) battery cells. Upper (first) and lower (second) rigid shear plates are attached to the upper (first) and lower (second) sides of the battery housing, respectively, with the battery cells enclosed between them.Between the battery cells and the upper (first) shear plate is an initial (first) adhesive layer containing both a primary (first) adhesive with a slow (first) curing time and a secondary (second) fixative adhesive with a different chemical composition and a fast (second) curing time. An additional (second) adhesive layer is positioned between the battery cells and the upper or lower shear plate at a distance from the first adhesive layer and also contains both the first and second adhesives. The first and second adhesive layers each have a central region and first and second side regions, respectively, located at opposite first and second points.are arranged on the second lateral sides of the central area, with the central area being defined by the first adhesive and the first and second side areas being defined by the second adhesive.

[0011] Further aspects of this disclosure relate to motor vehicles with rechargeable battery packs, in which the battery cells are fixed within a package housing using both fast- and slow-curing adhesives. As used herein, the terms "vehicle" and "motor vehicle" may be used interchangeably and synonymously to include any relevant vehicle platform, such as passenger cars (ICE, HEV, FEV, fuel cell, fully and partially autonomous vehicles, etc.), commercial vehicles, industrial vehicles, tracked vehicles, off-road and all-terrain vehicles, motorcycles, agricultural equipment, watercraft, aircraft, e-bikes, etc. In non-automotive applications, the disclosed concepts may be implemented for any logically relevant use, including self-sufficient power plants and portable power supply units, wind farms, photovoltaic systems, pumping systems, machine tools, server systems, etc.Although not limited per se, the disclosed concepts may be particularly advantageous for use with prismatic and cylindrical lithium-class battery cells.

[0012] In one example, a motor vehicle comprises a vehicle body with a passenger compartment, several wheels attached to the vehicle body (e.g., via corner modules coupled to a unibody or body-on-frame chassis), and other standard original equipment. In electric vehicles, one or more electric drive motors work alone (e.g., in FEV powertrains) or in conjunction with an internal combustion engine (e.g., in HEV powertrains) to drive one or more wheels, thus propelling the vehicle. A rechargeable drive battery pack is mounted on the vehicle body and can supply power to the drive motor(s).

[0013] Continuing the previous discussion, the vehicle's traction battery comprises a protective battery housing containing several cylindrical lithium-class battery cells. A rigid upper shear plate is attached to the top of the housing, and a rigid lower shear plate is attached to the bottom, with the battery cells positioned between the two shear plates. An electrical interconnect board, located within the battery housing near the upper shear plate, connects the battery cells electrically to each other and to a parcel bus. Inside the battery housing, near the lower shear plate, is a cell support plate that holds the battery cells.A first adhesive layer is in contact with the battery cells, positioned between the upper shear plate and the battery cells, and comprises both a primary adhesive with a medium- or high-strength chemical composition and a slow curing time, and a secondary adhesive with a low- or medium-strength chemical composition and a fast curing time. A second adhesive layer is located between the battery cells and the upper (or lower) shear plate, spaced apart from the first adhesive layer, and contains both the primary and secondary adhesives.

[0014] Aspects of this disclosure also relate to manufacturing processes, computer-readable media, and control logic for the manufacture or use of any of the disclosed adhesive assemblies, battery assemblies, and / or motor vehicles. An example presents a method for manufacturing a battery assembly. This representative method comprises, in any order and in any combination with any of the options and features disclosed above and below, receiving a battery casing; arranging a plurality of battery cells in the battery casing; attaching first and second shear plates to opposing first and second shear plates, respectively.second casing sides of the battery casing, such that the first and second shear plates are located between the battery cells; arranging a first adhesive layer between the battery cells and the first shear plate, wherein the first adhesive layer contains a first adhesive with a first chemical composition and a first curing time, and a second adhesive with a second chemical composition that differs from the first chemical composition and has a second curing time that is shorter than the first curing time; and arranging a second adhesive layer between the battery cells and the first or second shear plate, spaced apart from the first adhesive layer, and containing the first and second adhesives.

[0015] In all disclosed systems, methods, and vehicles, each adhesive layer can have a central adhesive region flanked on opposite sides by a first and a second lateral adhesive region. In this case, the central region is formed with the primary adhesive, while the two lateral regions are formed with the secondary adhesive. Each adhesive layer can also have a central segment located in the middle of the central region, formed with the secondary adhesive. Optionally, the two lateral regions of the adhesive layers can abut the respective sides of the central region. At least in some embodiments, the adhesive layers can be arranged in a predefined pattern, which can assume nonlinear, irregular geometric patterns extending along the length of the housing.

[0016] In all disclosed systems, methods, and vehicles, the battery cells comprise opposing upper (first) and lower (second) ends, with the initial (first) adhesive layer adjacent to the upper end of the cells. In this case, the additional (second) adhesive layer is arranged between the cells and the upper shear plate, with the initial adhesive layer embedded between the cells and the additional adhesive layer. Another possibility is that an integrated ICB arrangement electrically connects the battery cells to each other and, for example, to a high-voltage grid via a main DC bus. In this case, the first adhesive layer can be located on a lower (first) side of the electrical ICB, and the additional adhesive layer can be located on an upper (second) side of the ICB.The battery assembly can also include a cell carrier plate that supports the battery cells, as well as an optional (third) adhesive layer positioned between the lower (second) shear plate and the cell carrier plate, bonding them together. The third adhesive layer can contain only the primary adhesive or, if desired, both the primary and secondary adhesives. As a further option, a polymeric electrical insulating film can be applied to the additional (second) adhesive layer to adhere to the ICB. A further (fourth) adhesive layer can be positioned between the upper (first) shear plate and the insulating film, bonding them together. Like the third layer, the fourth adhesive layer can also contain only the primary adhesive or, if desired, both the primary and secondary adhesives.

[0017] In all disclosed systems, methods, and vehicles, the initial (first) adhesive layer can be applied to the upper (first) end of the battery cells, and the additional (second) adhesive layer can be applied to the lower (second) end of the battery cells, such that the additional adhesive layer is located between the cells and the lower shear plate. In this case, an electrical ICB arrangement can electrically connect the battery cells; the ICB arrangement is bonded to the battery cells by the first adhesive layer. Alternatively, a cell support plate can support the battery cells; an optional (third) adhesive layer, containing both the primary and secondary adhesives, is located between the lower shear plate and the cell support plate and adheres to them.A further optional (fourth) adhesive layer, containing a polymer foam adhesive, can be placed between the ICB assembly and the upper shear plate to bond them together.

[0018] In all disclosed systems, methods, and vehicles, the primary (first) adhesive can be a flame-retardant, medium- or high-strength polymer-based structural adhesive, while the bonding (second) adhesive can be a flame-retardant, low-strength polymer-based structural adhesive. In non-restrictive examples, the primary adhesive can be a multi-component polyurethane or acrylic hot melt or pressure-sensitive adhesive, and the secondary adhesive can be a moisture-curing, one-component synthetic polymer urethane adhesive. Another possibility is that the curing time of the primary adhesive is more than 10 minutes (e.g., about 15 to 20 minutes), while the curing time of the secondary adhesive can be less than about 6 minutes (e.g., about 2 to 5 minutes).

[0019] The above summary does not represent every embodiment or aspect of the present disclosure. Rather, the preceding summary merely provides an overview of some of the novel concepts and features set forth herein. The features and advantages mentioned above, as well as other features and associated advantages of this disclosure, will be readily apparent from the following detailed description of illustrated examples and representative modes of carrying out the disclosure, when considered in conjunction with the accompanying drawings and the attached claims. Furthermore, this disclosure expressly includes all combinations and subcombinations of the elements and features described above and below. Brief description of the drawings Fig. Figure 1 is a partially schematic side view of a representative motor vehicle with an electrified powertrain and a rechargeable drive battery pack containing a series of electrochemical battery cells attached with adhesive layers according to the aspects of the disclosed concepts. Fig. Figure 2 is a partially exploded, perspective view of a representative propulsion battery pack comprising upper and lower shear plates, an electrical interconnect board and a cell support plate holding a bundle of cylindrical battery cells, all structurally connected by multiple layers of adhesive according to the aspects of this disclosure. Fig. Figure 3 is a schematic side view of a representative battery arrangement with a battery cell that is fixed within a battery housing using intervening layers of primary and secondary adhesives in accordance with aspects of this disclosure. Fig. Figure 4 is a schematic side view of another representative battery arrangement with a battery cell that is fixed within a battery housing using interlayers or primary and secondary adhesives according to the aspects of this disclosure.

[0020] The present disclosure is suitable for various modifications and alternative forms, and some representative embodiments of the disclosure are illustrated by way of example in the drawings and are described here in detail. It should be understood, however, that the novel aspects of this disclosure are not limited to the particular forms illustrated in the drawings listed above. Rather, this disclosure encompasses all modifications, equivalents, combinations, permutations, groupings, and alternatives that fall within the scope of this disclosure, such as those covered, for example, by the attached claims. Detailed description

[0021] This disclosure can be realized in many different forms. Representative embodiments of the disclosure are illustrated in the drawings and are described in detail here, with the understanding that these embodiments serve as examples of the disclosed principles and do not represent limitations of the general aspects of the disclosure. Accordingly, elements and limitations described, for example, in the sections "Summary," "Introduction," "Description of the Invention," and "Detailed Description," but not expressly set forth in the claims, should not be considered as being included in the claims, either individually or collectively, either by implication, by conclusion, or otherwise.

[0022] For the purposes of this detailed description, unless expressly excluded: the singular includes the plural and vice versa; the words "and" and "or" apply in both the subjunctive and disjunctive moods; the words "every" and "all" mean "every one and all"; and the words "including," "containing," "comprehensive," "exhibiting," and the like each mean "including without limitation." Furthermore, words of approximation such as "approximately," "almost," "essentially," "generally," "about," and the like may be used here to mean "at, close to, or almost at" or "within 0-5% of" or "within acceptable manufacturing tolerances," or any logical combination thereof, for example.Finally, directional adjectives and adverbs such as "front", "rear", "inside", "outside", "starboard", "port", "vertical", "horizontal", "upwards", "downwards", "front", "stern", "left", "right", etc. can refer to a motor vehicle, e.g. to the forward movement of a motor vehicle when the vehicle is operated on a horizontal driving surface.

[0023] Now, with reference to the drawings, in which the same reference symbols refer to the same features in the different views, it is in Fig. Figure 1 shows a representative motor vehicle, generally referred to as 10, which is shown here for discussion purposes as an electric-powered sedan. The motor vehicle 10 shown—hereinafter also referred to as the “vehicle” or “car”—is merely an exemplary application with which aspects of this disclosure can be put into practice. Similarly, the integration of the present concepts into an FEV powertrain should be understood as a non-limiting implementation of the disclosed features. It is understood that the aspects and features of this disclosure can also be applied to other powertrain architectures, that they can be incorporated into any logically relevant vehicle type, and that they can be used for both automotive and non-automotive applications. Furthermore, only selected components of the motor vehicles and battery systems are shown and described in detail here.Nevertheless, the vehicles and systems described below may include numerous additional and alternative features and other available peripheral components to perform the various methods and functions of this disclosure.

[0024] The representative vehicle 10 of Fig. 1 is originally equipped with a vehicle telecommunications and information unit (“telematics unit”) 14, which communicates wirelessly, e.g., via cell towers, mobile switching centers, satellite services, etc., with a remote “off-board” cloud computing host service 24 (e.g., OnStar®). Some of the other vehicle hardware components 16, which are in Fig. The components generally represented in Figure 1 include, as non-limiting examples, an electronic video display device 18, a microphone 28, audio speakers 30, and various user input controls 32 (e.g., buttons, knobs, switches, touchpads, joysticks, touchscreens, etc.). These hardware components 16 function, in part, as a human-machine interface (HMI), enabling the user to communicate with the telematics unit 14 and other components located in and remote from the vehicle 10. For example, the microphone 28 allows the occupants to input verbal commands via an embedded speech processing unit with audio filtering, processing, and analysis modules. Conversely, the speakers 30 provide acoustic output to a vehicle occupant and can either be a standalone speaker intended for use with the telematics unit 14 or they can be part of an audio system 22 in the cabin.The audio system 22 is operationally connected to a network connection interface 34 and an audio bus 20 to receive analog information and reproduce it as sound via one or more loudspeaker components.

[0025] The telematics unit 14 is communicatively coupled to a network connection interface 34, suitable examples of which include twisted-pair / fiber optic Ethernet switches, parallel / serial communication buses, LAN (Local Area Network) interfaces, CAN (Controller Area Network) interfaces, and similar interfaces. The network connection interface 34 enables the vehicle hardware 16 to send and receive signals to each other and to various systems both on board and outside the vehicle body 12. This allows the vehicle 10 to perform various vehicle functions, such as modulating powertrain performance, activating braking systems, controlling the vehicle steering, regulating the charging and discharging process of a vehicle battery, and other automatic functions.The telematics unit 14 can, for example, exchange signals with a powertrain control module (PCM) 52, an ADAS (Advanced Driver Assistance System) module 54, an electronic battery control module (EBCM) 56, a battery charging module (BCM) 58, a brake system control module (BSCM) 60 and various other vehicle ECUs, e.g. a body control module (BCM), a steering control module (SCM), an engine control module (ECM), a sensor system interface module (SSIM), etc.

[0026] With continued reference to Fig. As shown in Figure 1, the telematics unit 14 is an in-vehicle computing unit that provides a range of services both individually and through its communication with other networked devices. This telematics unit 14 generally consists of one or more processors 40, each of which can be implemented as a discrete microprocessor, an application-specific integrated circuit (ASIC), or a dedicated control unit or control module. The vehicle 10 can provide central vehicle control via a central processing unit (CPU) 36, which is operationally coupled with a real-time clock (RTC) 42 and one or more electronic storage devices 38, each of which can take the form of a CD-ROM, a magnetic disk, an integrated circuit device, a solid-state drive (SSD), a hard disk drive (HDD), flash memory, semiconductor memory (e.g., various types of RAM or ROM), etc.

[0027] Long-range communication (LRC) with remote devices outside the vehicle can be provided via one, more, or all of the cellular, navigation, and positioning chipsets / components (e.g., GPS transmitters / receivers), or a wireless Internet Protocol modem (IP modem), all of which are listed together in section 44. Short-range wireless communication can be provided via an SRC device 46 (e.g., a Bluetooth® device or an NFC transceiver), a DSRC component 48, and / or a dual antenna 50. These communication devices can enable data exchange as part of operator-initiated pairing or periodic transmission in a vehicle-to-vehicle (V2V) or vehicle-to-everything (V2X) communication system, e.g., vehicle-to-infrastructure (V2I), vehicle-to-pedestrian (V2P), vehicle-to-device (V2D), vehicle-to-home (V2H), etc.

[0028] The CPU 36 receives sensor data from one or more sensing devices that use, for example, photodetection, radar, laser, ultrasound, optics, infrared, or other suitable technologies, including short-range communication technologies (e.g., DSRC) or ultra-wideband (UWB) radio technologies, to perform, for example, automated vehicle operation or a vehicle navigation service. According to the example shown, the motor vehicle 10 can be equipped with one or more digital cameras 62, one or more distance sensors 64, one or more vehicle speed sensors 66, one or more vehicle dynamics sensors 68, and the necessary filtering, classification, fusion, and analysis hardware and software for processing raw sensor data.The type, placement, number and interoperability of the distributed arrangement of vehicle sensors can be individually or collectively adapted to a specific vehicle platform to achieve the desired level of automation and the associated autonomous vehicle operation.

[0029] To propel the motor vehicle 10, an electrified powertrain is capable of generating a tractive torque and transmitting it to one or more of the vehicle's drive wheels 26. The powertrain is in Fig. 1 generally represented by an electric traction motor (M) 78 connected to a rechargeable energy storage system (RESS), which is represented as a chassis-mounted traction battery pack 70. The traction battery pack 70 generally comprises one or more battery modules 72, each containing a bundle or stack of battery cells 74, such as lithium, zinc, nickel, or organosilicon cells of the pouch, can, or cylindrical type. One or more electric machines, such as traction motor / generator (M) unit(s) 78, draw electrical power from the battery pack 70 and optionally supply electrical power to it. An inverter module (PIM) 80 electrically connects the battery pack 70 to the motor(s) 78 and modulates the transfer of electrical current between them. The concepts presented are similarly applicable to HEV- and ICE-based powertrains.The battery pack 70 can be designed such that the functions for module management, cell scanning, module-to-module and / or module-to-host communication, etc., are directly integrated into each battery module 72 and are performed by an integrated electronics package, such as a wireless cell monitoring unit (CMU) 76.

[0030] The vehicle 10 may initially be equipped with a rigid floor tray (not visible) extending over the top of the battery pack 70, for example, to separate the electrochemical cells 74 in the modules 72 from the occupants in the passenger compartment. An underbody guard (also not visible) may be fitted beneath the battery pack 70, for example, to protect the pack from water, snow, road debris, etc. The floor tray, the underbody guard, and the battery pack 70 may be anchored to the vehicle's chassis frame or, alternatively, connected to selected parts of the vehicle body 12 (e.g., in a unibody frame construction). The battery pack 70 has structural features to cope with dynamic load cases, such as non-harmonic and non-periodic compressive and torsional loads, during vehicle impact events.As described below, the battery pack 70 can have structural components with a battery housing embedded between impact-absorbing shear plates, which can aid in attaching the battery pack 70 to the vehicle frame. For example, an upper shear plate can be used to form part or all of the floor plate of the passenger compartment, while a lower shear plate can be used to form part or all of the skid plate of the chassis. A shear plate is often manufactured from high-strength, rigid materials with sufficient thickness / cross-sectional area to withstand in-plane loads many times the mass of the pack and typically has no surface contours or cutouts that could provide points of buckling during loading.

[0031] Next, with reference to Fig. Figure 2 shows a segment of a rechargeable energy storage system (RESS) in the form of a traction battery pack (or ‘battery assembly’) 100, suitable for storing and delivering high-voltage electrical energy, for example to power an electrically powered vehicle, such as the FEV vehicle 10 of Fig. 1. This battery pack 100 can represent a high-ampere deep-cycle vehicle battery system designed for a direct current (VDC) voltage of approximately 350 to 800 or more, depending, for example, on the desired vehicle range, the total vehicle weight, and the power ratings of the various accessory loads that draw electrical energy from the RESS. For this purpose, the pack 100 can be electrically connected to an electrical load or a power source, or both, such as multi-phase permanent magnet electric machines or other types of electric traction motors (M) 78. Each traction battery pack comprises an array (e.g., 100s or 1000s) of discrete electrochemical cells connected in series and / or parallel to achieve the desired overall voltage and current requirements.

[0032] The 100 drive battery pack from Fig. 2 is generally characterized by an arrangement of electrochemical battery cells housed in a protective battery casing. In the illustrated example, a staggered group of lithium battery cells 102 is arranged in a rectangular array and securely housed in a battery casing 104.

[0033] The battery housing 104 can be made of metallic, polymeric, or fiber-reinforced polymer (FRP) material, including combinations thereof, to meet various mechanical, manufacturing, and thermal design specifications. The battery housing 104 can have a relatively flat and lightweight design with a hexahedral shape, as shown, or can be designed in other regular and irregular geometric configurations to meet application-specific design and packaging parameters.Likewise, the battery arrangement 100 can contain a group of staggered cylindrical lithium-ion can cells sharing a common housing, as shown, or it can contain stacks or individual modules of battery cells, can contain bag-like cells, prism-type cells or another cell form factor and / or can use other suitable battery technologies, such as those above in relation to the battery cells 74 of . Fig. 1 described.

[0034] According to the representative battery configuration of Fig. 2 The battery housing 104 (or “battery container”) generally consists of several side walls which interact with optional top and bottom covers (not shown) to collectively enclose the battery cells 102. In particular, the battery housing 104 comprises a pair of sill-side side rails 106, spaced laterally apart and extending longitudinally along the vehicle chassis. The opposing front and rear ends of each side rail 106 are connected, for example, by bolted connections, to the front and rear bulkhead rails 108 and 110, respectively, which are spaced longitudinally apart and extend laterally across the width of the vehicle frame.The two side rails 106 attach the battery pack 100 to the sill sections of a vehicle chassis, while the front and rear bulkhead rails 108, 110 attach the battery pack 100 to the front and rear bulkhead sections of the vehicle chassis.

[0035] An integrated electrical interconnection board (ICB) assembly 112 sits on top of the battery cells 102 of Fig. 2 and is inserted between an upper (first) shear plate 120 and the top end of the bundled battery cells 102. The integrated ICB arrangement 112 can simultaneously function as an electrically isolating, cell-holding, cell-sensing, and cell-connecting solution, electrically connecting the battery cells 102 in series or parallel. The optional ICB hardware can include a flexible integrated circuit (FIC) with a variety of battery sensors, such as voltage, current, and temperature sensors (not shown).

[0036] A sensor conductor assembly (not shown) with electrical pads and conductor tracks connects the FIC sensor package to selected cells or cell groups of the battery pack 100. Bus connectors 116 on the front / rear rail 108, 110 electrically connect the ICB assembly 112 to the vehicle's high-voltage electrical system.

[0037] The underlying support for the battery cells 102 is a cell carrier panel (or “cell carrier plate”) 114 ( Fig. 3), which is arranged between a lower (second) shear plate 122 and the undersides of the battery cells 102. The cell support plate 114 can be an egg-shaped structure that physically supports the battery cells 102. If desired, the cell support plate 114 can be made of a thermally conductive material that allows the dissipation of heat generated by the cells, or alternatively, of a heat-resistant material that prevents heat transfer in the event of thermal runaway (TRP). In addition, the cell support plate 114 can form both a shock-absorbing gap between the lower shear plate 122 and the cells 102 and a thermal gap for the removal of hot air and gases that may be generated during a thermal event from the system.An optional thermoplastic composite plate (not shown) can be connected, glued, fastened or riveted to a bottom-facing underside of the lower shear plate 122 to provide additional protection for the arrangement of the battery pack 100.

[0038] Serving as a physical barrier between the passenger cabin and the battery pack 100, an upper (first) shear plate 120 is attached to an upper (first) side of the battery housing 104 of the battery pack, thus covering an inward-facing upper surface of the ICB arrangement 112. A lower (second) shear plate 122, acting as a protective underbody plate for the chassis and as a shield for the underside of the traction battery 100, is attached to a lower (second) side of the housing 104 opposite the upper shear plate 120, thus covering an outward-facing bottom surface of the cell support plate 114. In this arrangement, the two shear plates 120, 122 are sandwiched between the battery cells 102, without physically touching any of the cells 102.In the example shown, each shear plate 120, 122 essentially consists of a substantially flat plate without surface contours, cutouts, or shaped features to optimize load transfer in the plane across the heavy plates 120, 122. The shear plates 120, 122 can each be manufactured wholly or partially from a rigid metallic material (e.g., high-strength low-alloy steel (HSLA), aluminum / titanium composite, etc.) as a single-piece structure. While not strictly necessary, it may be desirable for the two shear plates 120, 122 to be structurally essentially identical, for example, to facilitate manufacturing and simplify design.

[0039] Next, with reference to the Fig. 3 and Fig. 4, in which equal parts from Fig. For which reference numerals 2 are used, examples of battery assemblies 200 and 300 with one or more battery cells 102 are shown, mounted in a battery housing 104 using intervening adhesive layers containing a combination of adhesives. Although they differ in appearance, all the features and options of battery packs 70 and 100 described above are available. Fig. 1 and Fig. 2 individually or in any combination into the battery arrangements 200 and 300 of the Fig. 3 and Fig. 4 are integrated and vice versa. A non-limiting point of similarity is that the cell(s) 102 of the battery assemblies 200, 300 are housed in a protective and electrically insulated outer battery casing 104, which is located between the upper and lower shear plates 120 and 122. Furthermore, an electrical ICB assembly 112 sits atop the battery cell(s) 102, positioned between the upper shear plate 120 and the top end of the cell(s) 102. Positive electrical terminals on the top of the cell(s) 102 mate with complementary busbar terminals integrated into the ICB assembly 112. A cell support plate 114, which may be configured as a TRP (Thermal Runaway Propagation) tray, sits on top and secures the battery cell(s) 102. As shown, the cell support plate 114 is located between the lower shear plate 122 and the lowest end of the cell(s) 102.The cell support plate 114 provides underlying support and spacing between the cells for the battery cell(s) 102.

[0040] To fix cell(s) 102 in position during assembly of the package, e.g. to assist in the alignment and mounting of the cells, and to secure cell(s) 102 during use of the package, e.g. to minimize vibrations and noise caused by the cells, battery assemblies 200 and 300 include Fig. 3 and Fig. Four multiple adhesive layers are arranged between the electrochemical cells and the surrounding internal battery components. Fig. For example, an initial adhesive layer 230 (first adhesive layer) is arranged between the cell and the ICB, and an additional adhesive layer 232 (second adhesive layer) is arranged between the battery cell(s) 102 and the upper shear plate 120, the additional adhesive layer 232 being spaced vertically upwards from the initial adhesive layer 230. There are also three optional adhesive layers in the battery assembly 200. Fig. 3: a lower adhesive layer 234 (third adhesive layer) arranged between the cell(s) 102 and the lower shear plate 122; an upper adhesive layer 236 (fourth adhesive layer) arranged between an electrical insulating film 224 and the upper shear plate 120; and an intermediate adhesive layer 238 (fifth adhesive layer) arranged between the cell(s) 102 and the cell support plate 114. In this arrangement, the battery components are located in the battery housing 104. Fig. 3 stacked from top to bottom as follows: upper shear plate 120, fourth adhesive layer 236, insulating film 224, second adhesive layer 232, ICB assembly 112, first adhesive layer 230, cell(s) 102, fifth adhesive layer 238, cell carrier plate 114, third adhesive layer 234 and lower shear plate 122. Although the battery assembly is shown with five adhesive layers, it may also include more or fewer adhesive layers or be arranged in a different order than shown (see e.g. Fig. 4) In addition, additional components may be inserted between or integrated into the layers shown.

[0041] Fig. Figure 4 shows optional and alternative battery components and stacking arrangements for each of the disclosed battery arrangements. In this example, a cell-to-ICB adhesive layer 330 (first adhesive layer) is arranged between the battery cell(s) 102 and the upper shear plate 120, and a cell-to-support adhesive layer 332 (second adhesive layer) is arranged between the battery cell(s) 102 and the lower shear plate 122, the additional adhesive layer 232 being spaced vertically downwards from the first adhesive layer 230. An optional lower adhesive layer 334 (third adhesive layer) is located between the cell support plate 114 and the lower shear plate 122. In this arrangement, the battery components are located within the battery housing 104. Fig. 4 stacked from top to bottom as follows: top shear plate 120, insulating foam adhesive layer 324, ICB arrangement 112, first adhesive layer 330, battery cell(s) 102, second adhesive layer 332, cell holder 114, third adhesive layer 334 and bottom shear plate 122. As used herein, the term 'layer' includes, but does not per se require, that a particular segment of the composite structure be a continuous plate or otherwise extend over the entirety of all other layers.

[0042] To secure the battery cell(s) 102 in a functional orientation with its adjacent components, one or more of the aforementioned adhesive layers contain both fast- and slow-curing adhesives. Both the first and second adhesive layers 230, 330, 232, 332 of the Fig. 3 and Fig. For example, each of the four components can contain a primary (first) adhesive 240 with a specific (first) chemical composition and a relatively slow curing time, as well as a (second) bonding adhesive 242 with a specific (second) chemical composition and a relatively fast curing time. For comparison: The optional third, fourth, and fifth adhesive layers 234, 236, 238 of Fig. 3 can essentially contain or consist of a single adhesive (e.g. the primary adhesive 240), while the third adhesive layer 334 consists of Fig. 4 can contain both the primary and secondary adhesives 240, 242. It is intended that the optional adhesive layers 234, 236, 238 of Fig. 3 may contain several types of adhesives (e.g., both the primary and secondary adhesives 240, 242) and the optional adhesive layer 334 of Fig. 4 may contain only a single adhesive. Likewise, each of the adhesive layers shown may contain additional and alternative types of adhesives, additives, fillers, modifiers, etc.

[0043] The primary adhesive 240 is chemically configured to firmly fix the battery cell(s) 102 in place for the daily use of the battery assembly 200. For this purpose, the primary adhesive 240 can be a flame-retardant, medium-strength, or high-strength (at least approximately 10 megapascals (MPa) shear strength) polymer-based structural adhesive. In contrast, the secondary adhesive 242 is chemically configured to fix the cell(s) 102 in place during the construction of the battery assembly 200. For this purpose, the secondary adhesive 242 can be a flame-retardant, low-strength (between approximately 2 and 5 MPa shear strength) polymer-based structural adhesive. As used here, the term “structural adhesive” can be defined to include metal-polymer and polymer-polymer adhesives that bond components in load-bearing structures and have an overlap shear strength of at least approximately 2 MPa (e.g.6.5+ MPa) and a T-peel strength (e.g., ASTM D1876) of at least about 0.5 Newtons per millimeter (N / mm) (e.g., 6.8+ N / mm) after exposure at room temperature. In some specific, but not limiting, examples, the primary adhesive 240 may be a multi-component, synthetic polymer polyurethane or acrylic adhesive with a slow curing time of more than about 10 minutes (e.g., about 15–20 minutes), while the secondary adhesive 242 may be a one-component, synthetic polymer, moisture-curing urethane adhesive with a fast curing time of less than about 6 minutes (e.g., about 2–5 minutes). The foam adhesive layer 324, on the other hand, may be a multi-component, synthetic polymer epoxy-based foam adhesive with a high strength-to-density ratio. In a specific, but not limiting, example, the foam adhesive layer 324 can be a low-density structural adhesive (e.g.less than about 1 g / cm3), high expansion rate (e.g. more than 100%) and low strength (> 5 MPa).

[0044] To fix the internal battery components while the primary structural adhesive cures, the adhesive layers 230, 232, 330, 332, 334 are combined in the Fig. 3 and Fig. Four fast-curing and one slow-curing adhesive are combined in a single layer (i.e., in a common, single plane as opposed to one layer on top of another) to ensure that both adhesives come into direct contact with the adjacent components being bonded. As an example, and without limitation, each of the adhesive layers 230, 232, 330, 332, 234 can be formed with several distinct adhesive regions, including a central adhesive region 240A flanked on the opposite left and right sides by the left and right adhesive regions 242A and 242B, respectively. An optional central segment 242C of the adhesive may be located in the middle of the central region 240A of the adhesive.In this example, the central segment 242C can be surrounded by and / or enclosed within the central region 240A, and the central region 240A can be surrounded by and / or enclosed between the left and right regions 242A and 242B. Similarly, the side regions 242A and 242B can each directly touch a corresponding side of the central region 240A, and the central region 240A can directly touch both sides of the central segment 242C. In this example, the central region 240A can be formed substantially or entirely of the primary adhesive 240, while the side regions 242A and 242B and the central segment 242C can be formed substantially or entirely of the secondary adhesive 242. It is conceivable that each adhesive layer 230, 232, 330, 332, 234 contains more or fewer regions than shown in the drawings (e.g.,(only a single primary adhesive area and only a single secondary adhesive area).

[0045] Again, referring to battery arrangement 200 of Fig. 3 The first adhesive layer 230 is located on top of and abuts the upper end of the battery cell(s) 102, positioned between the cell(s) 102 and the ICB assembly 112, bonding them together. The additional (second) adhesive layer 232 lies on top of and abuts the ICB assembly 112, positioned between the ICB assembly 112 and the insulating film 224, bonding them together. In this arrangement, the first adhesive layer 230 directly contacts a lower (first) side of the electrical ICB assembly 112, while the second adhesive layer 232 directly contacts an upper (second) side of the ICB assembly 112. The optional third adhesive layer 234 of Fig. Layer 3 is positioned between the lower shear plate 122 and the cell support plate 114, making direct contact and thus bonding them together. The optional fourth adhesive layer 236 is positioned between the upper shear plate 120 and the electrical insulating film 224, which may be a polymer-based dielectric barrier that insulates the ICB 112 from the upper shear plate 120, making direct contact and thus bonding them together. Finally, the optional fifth adhesive layer 238 is positioned between the cell(s) 102 and the cell support plate 114, making direct physical contact and thus bonding them together.

[0046] Again with reference to Fig.In this arrangement, the first adhesive layer 330 lies on the upper end of the battery cell(s) 102 and abuts it, while the second adhesive layer 332 lies below the lower end of the battery cell(s) 102 and abuts it, so that the battery cell(s) 102 are embedded between the two multiple adhesive layers 330, 332. In this stacked arrangement, the first adhesive layer 330 directly contacts the electrical ICB assembly 112 and the battery cell(s) 102, thereby bonding them together, while the second adhesive layer 332 directly contacts the battery cell carrier plate 114 and the cell(s) 102, thereby bonding them together. The third adhesive layer 334, on the other hand, is arranged between the lower shear plate 122 and the holder tray 114, directly contacts them, and thus bonds them together. The optional fourth adhesive layer 324 is arranged between the electrical ICB assembly 112 and the upper shear plate 120, directly touching and bonding them together, e.g.to electrically isolate the ICB 112 from the upper shear plate 120.

[0047] The total surface area of ​​each adhesive layer (the “adhesive joint”) on the ICB assembly 112 and / or the cell support plate 114 can be a function of both the adhesive dispensing pattern and the wetting properties of each adhesive during dispensing. Both the adhesive material and the dispensing path can be optimized to ensure that sufficient adhesive surface area is present at the various interfaces to support a predicted or predefined minimum load in the battery assembly. The fixing adhesive may need to be applied in a predefined pattern that ensures it counteracts any distortion of the mating parts. For example, if a battery component exhibits distortion in a primary direction, the fixing adhesive can be applied in a pattern parallel to the distortion to allow for a flatter profile of the parts for the next manufacturing process.The overall volume ratio of primary structural adhesive to secondary fastening adhesive can be optimized to meet manufacturing parameters and constraints. The fast-curing secondary adhesive can be selected for its ability to cure quickly and withstand residual stresses encountered during manufacturing. The volume ratio can be calculated to ensure sufficient strength to overcome temporary manufacturing stresses and the anticipated loads during battery assembly.

[0048] The presented concepts also relate to manufacturing systems and processes for producing fixture aids for adhesives. In many battery system architectures, structural adhesive bonds must be held in place until they reach a "green" strength. In accordance with the disclosed concepts, a fixture aid can be created to compress the adhesive bond until it reaches a predefined minimum green strength, after which the fixture aid can be removed. The shorter curing time of the secondary adhesive allows the system to be pressurized for a shorter time while the primary adhesive cures. One purpose of the fast-curing secondary fixture adhesive is to minimize the fixture time or pressing time for the initial bonding at green strength.For example, in a clamping application, the components to be joined can be smoothed and the adhesive bond compressed until a pre-stressed adhesive reaches the specified green strength; only then can the fixture be removed. Without the use of the pre-stressed adhesive, the clamping application may need to be maintained for a much longer time until the primary adhesive reaches green strength. If the adhesive fixture is released before green strength is reached, the components to be bonded may spring back into a distorted shape, thus reducing the bond strength and preventing the height and flatness specifications from being met.

[0049] Aspects of the present disclosure have been described in detail with reference to the illustrated embodiments; however, the person skilled in the art will recognize that many modifications can be made without departing from the scope of the present disclosure. The present disclosure is not limited to the exact construction and compositions disclosed herein; all modifications, changes, and variations apparent from the foregoing descriptions are within the scope of the disclosure as defined by the appended claims. Furthermore, the present concepts expressly include all combinations and subcombinations of the preceding elements and features.

Claims

[1] A battery arrangement (100) comprising: a battery housing (104); a plurality of battery cells (102) arranged in the battery housing (104); a first and a second shear plate (120, 122) which are attached to opposite first and second housing sides of the battery housing (104) and enclose the battery cells (102) between them; a first adhesive layer (230) arranged between the battery cells (102) and the first shear plate (120), wherein the first adhesive layer (230) comprises a first adhesive with a first chemical composition and a first curing time, and a second adhesive with a second chemical composition that differs from the first chemical composition and has a second curing time that is shorter than the first curing time; and a second adhesive layer (232) arranged between the battery cells (102) and the first or second shear plate (120, 122), spaced apart from the first adhesive layer (230) and containing the first and second adhesive; wherein the first and second adhesive layers (230, 232) each have a central region (240A) and a first and a second side region (242A, 242B) arranged on opposite first and second lateral sides of the central region (240A), wherein the central region (240A) is defined by the first adhesive and the first and second side regions (242A, 242B) are defined by the second adhesive. [2] Battery arrangement (100) according to claim 1, wherein the first and second adhesive layers (230, 232) each have a central segment (242C) located in the middle of the central area (240A) and defined by the second adhesive. [3] Battery arrangement (100) according to claim 1, wherein the first and second side regions (242A, 242B) abut the first and second lateral side of the central region (240A), respectively. [4] Battery arrangement (100) according to claim 1, wherein the battery cells (102) have opposite first and second ends, the first adhesive layer (230) adjoins the first end of the battery cells (102) and the second adhesive layer (232) is arranged between the battery cells (102) and the first shear plate (120), wherein the first adhesive layer (230) is arranged in a sandwich-like manner between the battery cells (102) and the second adhesive layer (232). [5] Battery arrangement (100) according to claim 1, further comprising an electrical interconnection board, ICB, which electrically connects the battery cells (102) together, wherein the first adhesive layer (230) is in contact with a first surface of the electrical ICB and the second adhesive layer (232) is in contact with a second surface of the electrical ICB opposite the first surface. [6] Battery arrangement (100) according to claim 5, further comprising: a cell carrier plate that supports the battery cells (102); and a third adhesive layer (234) which is arranged between the second shear plate (122) and the cell support plate (114) and bonds them together, wherein the third adhesive layer (234) contains the first adhesive. [7] Battery arrangement (100) according to claim 6, further comprising: an electrical insulating film (224) which is in contact with the second adhesive layer (232); and a fourth adhesive layer (236) which is arranged between the first shear plate (120) and the electrical insulating film (224) and bonds them together, the fourth adhesive layer (236) containing the first adhesive. [8] Battery arrangement (100) according to claim 1, wherein the battery cells (102) have opposite first and second ends, wherein the first adhesive layer (230) is located at the first end of the battery cells (102) and the second adhesive layer (232) is located at the second end of the battery cells (102), wherein the second adhesive layer (232) is arranged between the battery cells (102) and the second shear plate (122). [9] Battery arrangement (100) according to claim 1, further comprising an electrical interconnection board, ICB, which electrically connects the battery cells (102) to each other, wherein the first adhesive layer (230) is in contact with a first surface of the electrical ICB.

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