Battery pack with thermal management system

Abstract

A battery pack includes a battery pack housing and a battery module arranged in the battery pack housing. The battery pack housing is sealed and filled with a dielectric fluid. The battery module includes a fluid-permeable module housing and includes a fluid channel, and a plurality of electrochemical cells, the electrochemical cells being arranged in the module housing so that the battery terminals are exposed to the fluid arranged in the fluid channel. The battery pack includes a thermal management system having an inlet gas collection assembly arranged at a first end of the battery module, an outlet gas collection assembly arranged at a second end of the battery module, and a fluid pump, the fluid pump directing a fluid to the inlet gas collection assembly via a fluid delivery line, and receiving a fluid from the outlet gas collection assembly via a fluid return line.

Description

Technical Field

[0001] Battery packs power a wide range of technologies from portable electronics to renewable energy systems and eco-friendly vehicles. For example, hybrid electric vehicles use a battery pack and an electric motor in conjunction with an internal combustion engine to improve fuel efficiency. A battery pack may be formed from a plurality of battery modules, wherein each battery module includes a plurality of electrochemical cells. Within a battery module, the cells may be electrically connected in series or in parallel. Likewise, the battery modules may be electrically connected in series or in parallel within a battery pack. Background Art

[0002] In order to meet the space requirements of various applications and installation environments, different battery types have emerged, and the most common types in vehicles are cylindrical batteries, prismatic batteries, and soft-pack batteries. For example, cylindrical batteries are widely used because of their ease of manufacturing and stability. However, due to their curved shape, the packaging efficiency of cylindrical batteries in battery modules may be lower than that of some other types of batteries. In addition, since electrical connections are required at each end of the cylindrical battery, there are additional challenges in providing a battery module with effective space management. In addition, when the collectors are arranged at each opposite end of the battery, battery cooling via immersion in a liquid coolant is also challenging.

[0003] In some conventional battery modules, a battery support structure is provided to hold the batteries in a desired configuration and to provide battery cooling. However, such a battery support structure can be complex and have sufficient volume to further reduce the packaging efficiency of the battery module. There is a need for a power generation and storage device that is simple to use and manufacture, has a stable, orderly cylindrical battery arrangement within the battery module, and occupies a minimal volume of space within the battery module while providing battery cooling. Summary of the invention

[0004] In some aspects, a battery pack includes a battery pack housing, the battery pack housing including a container and a cover, the cover closing an open end of the container and being joined to the open end of the container via a fluid-impermeable seal. The battery pack housing is filled with a dielectric first fluid. The battery pack includes a battery module arranged in the battery pack housing. The battery module includes a module housing that is fluid-permeable and includes a fluid channel. The battery module has a plurality of electrochemical cells, the electrochemical cells are arranged in the module housing so that the battery terminals are exposed to the fluid arranged in the fluid channel. The battery pack includes a thermal management system, the thermal management system including: an inlet plenum assembly arranged at a first end of the battery module, the inlet plenum assembly including an inlet plenum chamber and an inlet flow divider arranged between the inlet plenum chamber and the module housing; an outlet plenum assembly arranged at a second end of the battery module, wherein the second end is opposite to the first end, the outlet plenum assembly including an outlet plenum chamber; and a fluid pump, the fluid pump directing fluid to the inlet plenum assembly via a fluid delivery line and receiving fluid from the outlet plenum assembly via a fluid return line.

[0005] In some embodiments, the inlet plenum and the inlet diverter have features that cooperate to direct fluid to the fluid channel.

[0006] In some embodiments, the inlet plenum chamber includes an end plate, an edge protruding from a first side of the end plate and extending along a portion of an outer periphery of the end plate, and a track protruding from the first side of the end plate, the track being configured to receive fluid diverted from the inlet diverter and guide the fluid to the fluid channel.

[0007] In some embodiments, the inlet plenum includes a fluid inlet opening that receives fluid from the fluid delivery line and is aligned with a surface of the inlet diverter. Each battery includes a first end, a second end, and a sidewall extending between the first end and the second end, wherein the second end is opposite to the first end and the polarity of the first end is opposite to the polarity of the second end. The fluid channel is arranged between the first end of a given battery and the inner surface of the module housing. The inlet diverter is arranged between the inlet plenum and the sidewall of a given battery and is configured to divert fluid leaving the fluid inlet opening to the fluid channel.

[0008] In some embodiments, the inlet flow splitter includes a flat first portion adjacent to the outer periphery of the inlet flow splitter, and a dome-shaped second portion surrounded by the first portion, the second portion of the dome protruding toward the inlet plenum. In addition, the inlet plenum includes a fluid inlet opening that receives fluid from the fluid delivery line and is aligned with the second portion of the surface of the inlet flow splitter.

[0009] In some embodiments, each battery includes a first end having a first terminal, a second end having a second terminal, and a side wall extending between the first end and the second end, wherein the second end is opposite to the first end and the polarity of the first terminal is opposite to the polarity of the second terminal. The module housing includes a tubular spacing structure and a frame. The spacing structure includes an open spacing structure first end, an open spacing structure second end opposite to the spacing structure first end, and a spacing structure side wall extending between the spacing structure first end and the spacing structure second end. The frame is configured to support the batteries within the battery module, and the frame surrounds the battery in a manner that covers the battery side wall of each battery and exposes the battery first end and the battery second end of each battery. The frame is arranged in the internal space of the spacing structure so that each battery first end and each battery second end face a corresponding one of the first wall portion and the second wall portion, respectively. The inlet diverter is fixed to a portion of the frame.

[0010] In some embodiments, the inlet diverter is fixed to the frame together with the inlet plenum, and the inlet plenum includes a spacer that maintains a spacing between the inlet diverter and a surface of the inlet plenum facing the module.

[0011] In some embodiments, the battery module includes a first battery module and a second battery module, and the inlet plenum assembly distributes fluid to the first battery module and the second battery module simultaneously.

[0012] In some embodiments, the inlet plenum assembly is configured to provide fluid to the first battery module at a first fluid flow rate and to provide fluid to the second battery module at a second fluid flow rate, wherein the first fluid flow rate is different from the second fluid flow rate.

[0013] In some embodiments, the inlet plenum includes a first fluid inlet opening that receives fluid from the fluid delivery line and is aligned with the first battery module, and a second fluid inlet opening that receives fluid from the fluid delivery line and is aligned with the second battery module. The first fluid inlet opening has a different diameter than the second fluid inlet opening.

[0014] In some embodiments, the outlet plenum assembly includes an outlet flow splitter disposed between the outlet plenum and the module housing.

[0015] In some embodiments, the outlet plenum is devoid of a fluid flow guide track.

[0016] In some aspects, a battery pack includes a battery pack housing including a container and a cover, the cover enclosing an open end of the container and joined to the open end of the container via a fluid-impermeable seal, the battery pack housing being filled with a dielectric first fluid. The battery pack includes battery modules arranged in the battery pack housing. Each battery module includes a fluid-permeable module housing and includes a fluid channel. Each battery module includes a plurality of electrochemical cells arranged in the module housing such that the battery terminals are exposed to the fluid arranged in the fluid channel. The battery pack includes a thermal management system that circulates the first fluid through the module housing of each battery module and is configured to be able to provide fluid to a given battery module at a fluid flow rate that is different from the fluid flow rate of other battery modules of the battery pack.

[0017] In some embodiments, the thermal management system includes: an inlet air collecting assembly arranged at a first end of the battery module, the inlet air collecting assembly including an inlet air collecting chamber and an inlet diverter arranged between the inlet air collecting chamber and the module housing; an outlet air collecting assembly arranged at a second end of the battery module, wherein the second end is opposite to the first end, and the outlet air collecting assembly includes an outlet air collecting chamber; and a fluid pump, which guides fluid to the inlet air collecting assembly via a fluid delivery line and receives fluid from the outlet air collecting assembly via a fluid return line.

[0018] In some embodiments, the inlet plenum and the inlet diverter have features that cooperate to direct fluid to the fluid channel.

[0019] In some embodiments, the inlet plenum chamber includes an end plate, an edge protruding from a first side of the end plate and extending along a portion of an outer periphery of the end plate, and a track protruding from the first side of the end plate, the track being configured to receive fluid diverted from the inlet diverter and guide the fluid to the fluid channel.

[0020] In some embodiments, the inlet plenum includes a fluid inlet opening that receives fluid from the fluid delivery line and is aligned with a surface of the inlet diverter. Each battery includes a first end, a second end, and a sidewall extending between the first end and the second end, wherein the second end is opposite to the first end and the polarity of the first end is opposite to the polarity of the second end. The fluid channel is arranged between the first end of a given battery and the inner surface of the module housing. In addition, the inlet diverter is arranged between the inlet plenum and the sidewall of a given battery and is configured to divert fluid leaving the fluid inlet opening to the fluid channel.

[0021] In some embodiments, the inlet flow splitter includes a flat first portion adjacent to the outer periphery of the inlet flow splitter, and a dome-shaped second portion surrounded by the first portion, the second portion of the dome protruding toward the inlet plenum. In addition, the inlet plenum includes a fluid inlet opening that receives fluid from the fluid delivery line and is aligned with the second portion of the surface of the inlet flow splitter.

[0022] In some embodiments, the battery module includes a first battery module and a second battery module, and the inlet air collecting assembly simultaneously distributes fluid to the first battery module and the second battery module, wherein the inlet air collecting assembly is configured to be able to provide fluid to the first battery module at a first fluid flow rate and to provide fluid to the second battery module at a second fluid flow rate, wherein the first fluid flow rate is different from the second fluid flow rate.

[0023] In some embodiments, the inlet plenum includes: a first fluid inlet opening that receives fluid from the fluid delivery line and is aligned with the first battery module, and a second fluid inlet opening that receives fluid from the fluid delivery line and is aligned with the second battery module. The first fluid inlet opening has a different diameter than the second fluid inlet opening.

[0024] Each battery module includes a bus bar assembly that provides interconnection of battery terminals within the battery module. Each bus bar assembly includes a substrate and an insulating layer attached to the surface of the substrate facing the battery. The insulating layer is electrically and thermally insulating and is also flame retardant. In some embodiments, each surface of the insulating layer includes a pressure sensitive adhesive, whereby the insulating layer is attached to the substrate and the battery ends. The insulating layer can prevent short circuits when the battery expands and contracts within the module. In addition, the insulating layer is flame retardant, so that its electrical and thermal isolation properties can be maintained in the event of thermal runaway of the battery.

[0025] In a battery module, the positive terminal of each battery is connected to a bus bar assembly via a first electrical connector, and the negative terminal of the battery is connected to another bus bar assembly via a second electrical connector. In some embodiments, the first electrical connector and the second electrical connector are configured such that the current carrying capacity of the first electrical connector is less than the current carrying capacity of the second electrical connector. By providing a first electrical connector and a second electrical connector in which the current carrying capacity of the first electrical connector is less than the current carrying capacity of the second electrical connector, each battery is electrically connected to a corresponding bus bar assembly so that the electrical connection to the positive terminal of the battery fails before the electrical connection to the negative terminal of the battery, thereby disconnecting the internal circuit of the battery module. An open circuit in the internal circuit of the battery module 40 can help prevent the unlikely situation where an internal short circuit in the battery may cause a direct short circuit between the batteries of the battery module.

[0026] The battery pack includes a plurality of battery modules, and the battery modules are bundled in a subassembly called a box. The box is arranged in a battery pack housing, and the interior space of the battery pack housing is filled with a dielectric, non-flammable and chemically inert engineering fluid. Although the battery modules may be passively cooled by immersion in the engineering fluid, the battery pack includes a thermal management system in which the engineering fluid is actively driven across the battery surface. This is achieved by delivering the fluid to each box, distributing the fluid to the battery modules within the box using an inlet plenum assembly, collecting the fluid that has been heated by the battery using an outlet plenum assembly, and removing the heated fluid from the battery. By providing passive and active cooling of the battery, the battery function is improved and the battery durability is increased.

[0027] Since the battery pack is filled with engineered fluid, the battery module and battery case do not include fluid sealing features to facilitate active cooling. In this way, the components of the battery module, case, and thermal management system are simplified relative to the active thermal management system of some conventional battery packs, and are therefore easier to manufacture and less expensive.

[0028] Advantageously, the thermal management system can be configured so that the fluid flow rate of the cooling fluid delivered to each battery module can be set individually, thereby allowing the flow rate of the cooling fluid to be increased in areas where it is detected that the temperature is higher than other areas. In this way, the operating temperature of each battery module of the battery pack can be controlled individually, and the overall temperature of the battery pack can be balanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a side view of the battery pack;

[0030] Figure 2 yes Figure 1 A perspective view of a battery pack of , wherein a cover and some auxiliary structures are omitted to illustrate the arrangement of the box in the battery pack housing;

[0031] Figure 3 is a perspective view of the box;

[0032] Figure 4 is a perspective view of a cartridge, wherein a fluid inlet plenum assembly and an outlet plenum assembly are omitted to illustrate a battery module disposed within the cartridge;

[0033] Figure 5 is a perspective view of a box housing with a battery module omitted;

[0034] Figure 6 is a perspective view of a battery module;

[0035] Figure 7 is along Figure 6 The cross-sectional view of the battery module as seen from line 7-7;

[0036] Figure 8 is an exploded perspective view of a battery module;

[0037] Fig. 9 is a partially exploded perspective view of an electrochemical cell;

[0038] Fig.10 is a schematic diagram of the arrangement of batteries in a battery module;

[0039] Fig.11 is a side view of a battery array within a battery module, showing the arrangement of the batteries in quadrants;

[0040] Fig.12 It is a perspective view of a separate frame;

[0041] Fig.13 is a perspective view of a frame including a battery;

[0042] Fig.14 is a perspective view of an individual bus bar assembly viewed from a first side of a battery module;

[0043] Fig.15 is a perspective view of first to third bus bar assemblies;

[0044] Fig.16 is a perspective view of a second bus bar assembly;

[0045] Fig.17 is a perspective view of a first bus bar assembly;

[0046] Fig.18 is a perspective view of a third bus bar assembly;

[0047] Fig.19 is a perspective view of the fourth and fifth bus bar assemblies;

[0048] Fig. 20 is a perspective view of an individual bus bar assembly viewed from a second side of the battery module;

[0049] Fig.21 is along Fig.15 An end view of the first to third bus bar assemblies seen in the direction of arrow A;

[0050] Fig. 22 is a perspective view of a first bus bar assembly;

[0051] Fig.23 is an exploded view of a first bus bar assembly;

[0052] Fig.24 is a perspective view of a fifth bus bar assembly;

[0053] Fig.25 is an exploded view of the fifth bus bar assembly;

[0054] Fig.26 yes Fig.29 A detailed view of a cross-sectional view of a battery module shown in dashed lines;

[0055] Fig. 27 is a detailed view of a portion of a battery module showing the electrical connection between the negative terminal of the battery and the corresponding bus bar;

[0056] Fig.28 is a detailed view of a portion of a battery module showing the electrical connection between the positive terminals of the batteries and the corresponding bus bars;

[0057] Fig.29 is a cross-sectional view of a battery module with a spacing structure omitted;

[0058] Fig.30 is a cross-sectional view of a battery module including a spacing structure;

[0059] Fig.31 is a perspective view of a separate compartment structure;

[0060] Fig.32 is an end view of a separate spacer structure;

[0061] Fig.33 yes Fig.30 A detailed view of a cross-sectional view of a battery module shown in dashed lines;

[0062] Fig.34 is an exploded perspective view of the box;

[0063] Fig.35 is an exploded view of the box’s battery modules and separators;

[0064] Fig.36 is a top view of a battery pack housing, wherein a cover and auxiliary structures are omitted to illustrate a thermal management system, wherein a pump is schematically shown;

[0065] Fig.37 is a perspective view of a separate fluid transport portion of a thermal management system;

[0066] Fig.38 is a perspective view of a separate fluid delivery portion of the thermal management system, showing the connection between the fluid delivery portion and two cartridges;

[0067] Fig.39 is a perspective view of a separate fluid return portion of a thermal management system;

[0068] Fig.40 is a perspective view of a separate fluid return portion of the thermal management system, showing the connection between the fluid return portion and two cassettes;

[0069] Fig.41 is a perspective exploded view of the cartridge with the cartridge housing omitted and the inlet plenum assembly illustrated;

[0070] Fig.42 is a perspective view of a portion of the box showing an inlet plenum assembly;

[0071] Fig.43 is a perspective view of a portion of a box showing an inlet plenum assembly including a manifold portion connected to an inlet opening of the inlet plenum assembly;

[0072] Fig.44 is along Fig.42 A cross-sectional view of the inlet gas collection assembly as viewed from line 44-44;

[0073] Fig.45 is along Fig.42 A cross-sectional view of the inlet gas collection assembly as viewed from line 45-45;

[0074] Fig.46 is along Fig.42 A cross-sectional view of the inlet gas collection assembly as viewed from line 46-46;

[0075] Fig.47 is a perspective view of a module-facing surface of an inlet plenum assembly;

[0076] Fig.48 yes Fig.47 An exploded perspective view of an inlet gas collecting assembly;

[0077] Fig.49 is an exploded perspective view of the cartridge with the cartridge housing omitted and the outlet plenum assembly shown;

[0078] Fig.50 is a perspective view of a portion of the box showing an outlet plenum assembly;

[0079] Fig.51 is a perspective view of a portion of a cassette showing an outlet plenum assembly including a fluid return branch line connected to an outlet opening of the outlet plenum assembly;

[0080] Fig.52 yes Fig.51 Magnified perspective view of

[0081] Fig.53 is a perspective view of a module-facing surface of an outlet gas collection assembly;

[0082] Fig.54 yes Fig.53 An exploded perspective view of an outlet gas collection assembly;

[0083] Fig.55 is a side view of a separate pressure management system;

[0084] Fig.56 is an exploded side view of the pressure management system showing the relative positions of the cover and container portions of the battery pack housing;

[0085] Fig.57 is an end view of a separate pressure management system;

[0086] Fig.58 is a top perspective view of the first bladder;

[0087] Fig.59 is along Fig.58 A cross-sectional view of the first sac as seen along line 59-59;

[0088] Fig.60 is an exploded perspective view of the second bladder, the third bladder and the protective shell;

[0089] Fig.61 is a cross-sectional view of a portion of a battery pack showing details of the main fittings and the vent block;

[0090] Fig.62 is a cross-sectional view of the ventilation block;

[0091] Fig.63 and Fig.64 is an additional cross-sectional view of a portion of a battery pack showing details of the main fittings and vent block;

[0092] Fig.65 It is an exploded view of the main accessories;

[0093] Fig.66 It is a cross-sectional view of a part of the main fitting. DETAILED DESCRIPTION

[0094] Reference Figure 1-7 , the battery pack 1 is configured to provide power to the vehicle powertrain and can therefore operate at a relatively high voltage. As used herein, the term high voltage refers to a voltage greater than 100V. For example, in some embodiments, the battery pack 1 can operate at 400V, while in other embodiments, the battery pack 1 can operate at 800V. The battery pack 1 includes a battery pack housing 2 for accommodating battery modules 40, and each battery module 40 includes an electrochemical cell 200. The battery pack housing 2 includes a container 4 and a lid 6 that closes the open end of the container 4, and the lid is connected to the open end of the container via a fluid-impermeable seal 8. The battery pack housing 2 has a flat shape. As used herein, the term "flat shape" refers to a height hp that is smaller than the length lp and the width wp. In the battery pack housing 2, the height hp corresponds to the distance between the lid 6 and the bottom of the container 4.

[0095] The battery pack housing 2 is filled with the engineering fluid (e.g., completely filled, filled to overflowing), and is sealed to prevent leakage and / or evaporation of the engineering fluid. The engineering fluid is dielectric, non-flammable, and chemically inert. For example, the fluid may be ethoxy-nonafluorobutane, such as Novec manufactured by 3M Company of Minnesota, USA. TM 7200. The battery pack 1 includes a thermal management system 500 that provides active cooling to the battery 200 of each battery module 40 within the fluid-filled battery pack 1, as discussed in detail below. In addition, the battery pack 1 includes a pressure management system 300 that allows the closed, fluid-filled and sealed battery pack housing 2 to adapt to changes in ambient temperature and pressure, as discussed in detail below.

[0096] In some embodiments, the battery pack 1 may include 12 battery modules 40 or more. In the embodiment shown, the battery pack 1 includes 24 battery modules 40. For ease of handling and assembly, the battery modules 40 are arranged into subassemblies each containing three battery modules 40 (1), 40 (2), 40 (3). The subassembly of the battery module 40 is referred to as a "box" 20. The three battery modules 40 (1), 40 (2), 40 (3) of the subassembly are supported in a box housing 22. In the embodiment shown, the battery pack housing 2 receives and supports eight boxes 20, which are arranged in a two-dimensional array in the battery pack container 4.

[0097] Each battery module 40(1), 40(2), 40(3) of a given cartridge 20 may be electrically connected to the other battery modules of the given cartridge 20. Similarly, each cartridge 20 within a battery pack 1 is electrically connected to the other cartridges 20 of the battery pack 1. The electrical connections may be in parallel, in series, or a combination of parallel and series, as desired for a particular application.

[0098] Reference Figure 8 , all battery modules 40 of the battery pack 1 are substantially the same. For this reason, only one battery module 40 is described in detail, and the same or similar elements are represented by the same reference numerals. The battery module 40 includes an array 202 of electrochemical cells 200. The battery 200 is supported within the battery module 40 by a frame 50, which holds the battery 200 in a two-dimensional array 202, as discussed in detail below. The frame 50 is arranged in a spacing structure 80, which provides a fluid channel that guides an engineering fluid used as a coolant to an exposed portion of the battery 200, as discussed in detail below. The frame 50 and the spacing structure 80 cooperate to provide a battery module housing 46 including a positive terminal 42 and a negative terminal 44. The batteries 200 are electrically connected to each other and to the positive or negative terminals 42, 44 of the corresponding battery modules using bus bars 130, which are configured to simply and reliably accommodate high currents, as discussed in detail below.

[0099] Reference Figure 9-10 and Fig.13 , the battery 200 is a cylindrical lithium-ion battery. Each battery 200 includes a cylindrical battery housing 203 having a container portion 204 and a cover portion 205 that closes the open end of the container portion 204. The cover portion 205 is arranged on the first end 207 of the battery 200, and the container portion 204 is sealed by an electrically insulating gasket 206. The container portion 204 includes a closed end arranged at the second end 208 of the battery housing 203, and the second end 208 is opposite to the first end 207 of the battery including the cover portion 205. The container portion 204 includes a battery housing sidewall 210 protruding from the closed end 208 and perpendicular to the closed end 208. The container portion 204 is elongated along the longitudinal axis 212 of the battery extending between the first end 207 of the battery and the second end 208 of the battery. That is, the longitudinal axis 212 extends parallel to the battery housing sidewall 210. Each battery 200 has the same shape and size, including the battery diameter d1.

[0100] The electrode assembly 226 is sealed in the battery case 203 together with the electrolyte to form a power generation and storage unit. The electrode assembly 226 includes a stacked arrangement of a positive electrode 218, a first separator 222, a negative electrode 220, and a second separator 224, wherein the stacked arrangement has been rolled up to provide a "jelly roll". One of the electrodes, such as the positive electrode 218, is electrically connected to the lid portion 205, which serves as the positive terminal 214 of the battery 200. In addition, the other electrode, such as the negative electrode 220, is electrically connected to the container portion 204, which serves as the negative terminal 216 of the battery 200.

[0101] Due to the curved shape of the battery, the cylindrical battery 200 may have a lower packing efficiency in the battery module than some other battery types. In order to maximize the packing efficiency of the cylindrical battery 200, the battery 200 is stored in the battery module 40 in a "close-packed" configuration. As used herein, the term "close-packed" refers to a configuration in which the battery 200 is arranged in a row side by side. In addition, when the battery 200 is seen in an end view ( Fig. 9), alternating rows are relatively offset in a direction parallel to the row so that the center 228 of the battery 200 in one row is between the center 228 of the battery 200 in an adjacent row. In addition, each battery 200 is in direct contact with the adjacent batteries in its own row (i.e., 200(1), 200(2)) and in direct contact with the adjacent batteries in the adjacent row (i.e., 200(3), 200(4), 200(5), 200(6)). Sometimes, this battery configuration is also referred to as a "hexagonal stacking" configuration. In the illustrated embodiment, the array 202 includes 8 rows of batteries 200, and each row includes 38 batteries. In other embodiments, the array 202 may include more or fewer rows and / or more or fewer batteries 200 in each row, depending on the needs of a specific application. The batteries 200 in the array 202 are aligned so that when the battery 200 is viewed in a side view, the end 207 or 208 of each battery 200 is arranged in a first plane P1 ( Fig.13 ), the first plane P1 is common to each battery 200 in the array 202.

[0102] refer to Fig.11 In the array 202, the batteries 200 are grouped in quadrants Q1, Q2, Q3, Q4, and all batteries 200 in a given quadrant have the same orientation, so that terminals of the same polarity are arranged on the same side of the given quadrant. In addition, when the array 202 is viewed in a direction facing the battery ends 207, 208, the batteries 200 in adjacent quadrants have opposite polarities. For example, Fig.10 , one side of the array 202 is shown, whereby 200 cells can be seen in an end view. Fig.10 , the first and second quadrants Q1, Q2 are side-by-side and overlie the third and fourth quadrants Q3, Q4 which are also side-by-side. The cells 200 of the first quadrant Q1 and the fourth quadrant Q4 have the same orientation, e.g., an orientation in which the second end 208 (and therefore the negative terminal 216) of the cells 200 is visible. In addition, the cells 200 of the second and third quadrants Q2, Q3 have the same orientation, e.g., an orientation in which the first end 207 (and therefore the positive terminal 214) of the cells 200 is visible. By grouping the cells 200 in the quadrants Q1, Q2, Q3, Q4, providing electrical connections between the cells 200 in the array 202 via the bus bars 130 is simplified.

[0103] refer to Fig.12 and Fig.13, the frame 50 holds the batteries 200 in a tightly packed arrangement. The frame 50 includes a cover plate 52, a bottom plate 54, a first end cap 56 connecting a first end of the cover plate 52 to a first end of the bottom plate 54, and a second end cap 58 connecting a second end of the cover plate 52 to a second end of the bottom plate 54. In addition, the frame 50 includes a central wall 60 that joins the cover plate 52 to the bottom plate 54 and is disposed approximately in the middle of the first and second end caps 56, 58. The first and second end caps 56, 58 and the central wall 60 are perpendicular to the cover plate 52 and the bottom plate 54. The cover plate 52, the bottom plate 54, the first and second end caps 56, 58, and the central wall 60 are thin plates with a width wf corresponding to the length lc of the battery 200, wherein the length lc of the battery 200 is the distance between the first end 207 (e.g., the cover portion 205) and the closed second end 208. The cover plate 52 and the bottom plate 54 have a length that accommodates the length la of the battery array 202, which in turn corresponds to the size of the row of the battery 200. Additionally, the first and second end caps 56 , 58 and the center wall 60 are sized to accommodate the height ha of the battery array 202 .

[0104] The frame 50 surrounds the periphery of the battery array 202 and covers the side walls 210 of each battery in the array 202. In other words, the batteries 200 are oriented so that the longitudinal axis 212 of each battery 200 is parallel to each of the cover plate 52, the bottom plate 54, the first and second end caps 56, 58, and the center wall 60. In this way, each of the first and second ends 207, 208 of the battery and, therefore, the battery positive and negative terminals 214, 216 of each battery 200 are exposed at the respective open sides 72, 74 of the frame 50.

[0105] The cell-facing surfaces 62, 64, 66, 68, 70 of the cover plate 52, the bottom plate 54, the first and second end caps 56, 58, and the center wall 60 are contoured to accommodate the cylindrical shape of the cell sidewalls 210 of the outermost cells 200 of the array 202. For example, the cell-facing surfaces 62, 64, 66, 68, 70 may have a wavy contour that receives and supports the outermost cells of the array 202. In some embodiments, to further secure and maintain the cells 200 in a desired close-packed configuration, the cell housing 203 of a given cell 200 may be fastened to the cell housing 203 of each adjacent cell 200 using an adhesive.

[0106] The outwardly facing surface of each of the first and second end caps 56, 58 may include a first groove 76 extending in a width direction of the first and second end caps 56, 58 (e.g., in a direction parallel to the longitudinal axis 212 of the battery 200). The first groove 76 has a curved concave surface that receives and supports the retaining rod 28, as discussed further below. The outwardly facing surface of each of the first and second end caps 56, 58 may include a second groove 78 extending in a height direction of the first and second end caps 56, 58 (e.g., in a direction perpendicular to the longitudinal axis 212 of the battery 200). The second groove 78 has a curved concave surface that receives and supports a wiring harness (not shown).

[0107] refer to Figure 8 and Figure 14-21 , the bus bar 130 provides interconnection of battery terminals within the battery module 40. The bus bar 130 includes five bus bar assemblies 130(1), 130(2), 130(3), 130(4), 130(5) that cooperate to electrically connect the batteries 200 of a given quadrant Q1, Q2, Q3, Q4 in parallel and provide series electrical connections between the quadrants Q1, Q2, Q3, Q4 and the terminals 42, 44 of the battery module 40. For example, the first bus bar assembly 130(1) provides parallel electrical connections between the negative terminals 216 of a first subset of the batteries 200 in the battery array 202, wherein the batteries 200 of the first subset correspond to the batteries 200 in the first quadrant Q1. In addition, the first bus bar assembly 130(1) connects the batteries 200 of the first quadrant Q1 in series to the negative terminal 44 of the battery module.

[0108] The second bus bar assembly 130(2) provides parallel electrical connections between the positive terminals 214 of a second subset of the batteries 200 in the battery array 202, wherein the batteries 200 of the second subset correspond to the batteries 200 in the second quadrant Q2. In addition, the second bus bar assembly 130(2) connects the batteries 200 in the second quadrant Q2 in series to the positive terminal 42 of the battery module.

[0109] The third bus bar assembly 130(3) provides parallel electrical connections between the positive terminals 214 of a third subset of the batteries 200 in the battery array 202, wherein the batteries 200 of the third subset correspond to the batteries 200 in the third quadrant Q3. In addition, the third bus bar assembly 130(3) provides parallel electrical connections between the negative terminals 216 of a fourth subset of the batteries 200 in the battery array 202, wherein the batteries 200 of the fourth subset correspond to the batteries 200 in the fourth quadrant Q4. In addition, the third bus bar assembly 130(3) connects the batteries 200 in the third quadrant Q3 in series with the batteries 200 in the fourth quadrant Q4.

[0110] The fourth bus bar assembly 130(4) provides parallel electrical connections between the positive terminals 214 of the first subset of the batteries 200 in the battery array 202, such as the batteries 200 in the first quadrant Q1. In addition, the fourth bus bar assembly 130(4) provides parallel electrical connections between the negative terminals 216 of the third subset of the batteries 200 in the battery array 202, such as the batteries 200 in the third quadrant Q3. In addition, the fourth bus bar assembly 130(4) connects the batteries 200 in the first quadrant Q1 in series with the batteries in the third quadrant Q3.

[0111] The fifth bus bar assembly 130(5) provides parallel electrical connections between the negative terminals 216 of the second subset of the batteries 200 in the battery array 202, such as the batteries 200 in the second quadrant Q2. In addition, the fifth bus bar assembly 130(5) provides parallel electrical connections between the positive terminals 214 of the fourth subset of the batteries 200 in the battery array 202, such as the batteries 200 in the fourth quadrant Q4. In addition, the fifth bus bar assembly 130(5) connects the batteries 200 in the second quadrant Q2 in series with the batteries in the fourth quadrant Q4.

[0112] Each of the five bus bar assemblies 130(1), 130(2), 130(3), 130(4), 130(5) includes a conductive substrate 138, an insulating layer 180 arranged on the battery terminal side 132 of the substrate 138, and an electrical connector 160 that provides an electrical connection between the substrate 138 and each corresponding battery terminal 214 or 216.

[0113] The substrate 138 is a rigid, conductive thin plate. The substrate 138 includes a first side 132 facing the battery 120, a second side 134 opposite the first side 132, and an outer periphery 136. Each substrate 138 includes at least one tab 148 protruding from the outer periphery 136. The tab 148 is folded toward the first side 132 of the substrate so that it extends perpendicular to the first side 132 of the substrate. The tab 148 allows the voltage and temperature sensor leads to be electrically connected to the substrate 138. In addition, fasteners (not shown) are used to secure the voltage and temperature sensor leads together with the substrate 138 to the frame end caps 56, 58 via the openings in the tabs 48.

[0114] Each substrate 138 includes an alpha portion 140 corresponding to an area forming parallel electrical connections between the substrate 138 and the batteries 200 of a given quadrant, and a beta portion 150 corresponding to an area providing a series electrical connection, such as between adjacent alpha regions or between alpha regions and module terminals 42, 44. The outer perimeter 132 of the alpha portion 140 curves to conform to the contours of the battery array 202.

[0115] The first, second and third bus bar assemblies 130(1), 130(2), 130(3) provide electrical connections between the batteries 200 on the first side of the battery array 202, and the base plate 138 of the first, second and third bus bar assemblies 130(1), 130(2), 130(3) is generally L-shaped. The first leg of the "L" covers the first side of the battery array (e.g., covers the end of the battery including the battery terminal 214 or 216). The first leg of the "L" corresponds to the α portion 140 of the base plate 138. In addition, the second leg of the "L" is perpendicular to the first leg and covers a portion of the frame 50 (e.g., covers the side wall of the battery 200). The second leg of the "L" corresponds to the β portion 150 of the base plate 138.

[0116] The α portion 140 is located in a second plane P2 parallel to the first plane P1, and the ends of the batteries 200 are aligned in the first plane P1. The α portion 140 includes a main connection through hole 142. A main connection through hole 142 is provided for each battery 200 of the quadrant, and each main connection through hole 142 is aligned with one end of the corresponding battery 200, thereby exposing the battery terminal 214 or 216. The main connection through hole 142 is circular, and its diameter d2 is smaller than the diameter d1 of the battery 200. The main connection through hole 142 exposes the end of the battery so that an electrical connector 160, such as a welding wire, can be used to make an electrical connection between the exposed battery terminal 214 or 216 and the α portion 140. The α portion also includes a main flow hole 144 aligned with a small gap between the side walls 210 of adjacent batteries 200. As a reflection of the hexagonal packing arrangement of the batteries 200, there are six main flow through holes 144 arranged around the periphery of each main connection through hole 142. The main flow through hole 144 has a small diameter d3 corresponding to the small size of the gap, and its diameter is smaller than the diameter of the main connection through hole 142. For example, in the illustrated embodiment, the diameter d3 of the main flow through hole 144 is about 10% to 25% of the diameter d2 of the main connection through hole 142.

[0117] The β portion 150 is located in a third plane P3 perpendicular to the second plane P2. In the base plate 138 of the first and second bus bar assemblies 130(1), 130(2), the β portion 150 covers the frame cover 52. The β portion 150 of the first bus bar assembly 130(1) is electrically connected to the negative terminal 44 of the battery module, and the β portion 150 of the second bus bar assembly 130(2) is electrically connected to the positive terminal 42 of the battery module. In some embodiments, the β portion 150 of the first and second bus bar assemblies 130(1), 130(2) can be made integrally with the corresponding terminals 42, 44, and in other embodiments, the β portion 150 of the first and second bus bar assemblies 130(1), 130(2) can be joined to the corresponding terminals, for example, by welding. In the illustrated embodiment, the negative terminal 44 of the battery module integrally protrudes from one edge of the β portion 150 of the first bus bar assembly 130(1), and the positive terminal 42 of the battery module integrally protrudes from one edge of the β portion 150 of the second bus bar assembly 130(2). In this way, the terminals 42, 44 of the battery module are located in the same plane as the β portions 150 of the first and second bus bar assemblies 130(1), 130(2). In the base plate 138 of the third bus bar assembly 130(3), the β portion 150 covers the frame bottom plate 54 and provides a series electrical connection between the third quadrant Q3 and the fourth quadrant Q4.

[0118] In the substrate 138 of the first, second and third bus bar assemblies 130(1), 130(2), 130(3), the thickness tb of the β portion 150 is greater than the thickness ta of the α portion 140, wherein the thickness of the substrate of the α portion corresponds to the distance ( tb ) between the first side 132 and the second side 134. Fig.21 ). The larger thickness 150 of the β portion accommodates the high current in this area. In addition, the β portions 150 of the first, second, and third bus bar assemblies 130(1), 130(2), 130(3) may include bar-shaped openings 152. The openings 152 receive tabs 55 that protrude from the outwardly facing surfaces of the frame cover and base plates 52, 54, thereby allowing the bus bar assemblies 130(1), 130(2), 130(3) to be properly aligned and oriented relative to the frame 50, and are used to maintain the bus bar assemblies 130(1), 130(2), 130(3) to be properly aligned relative to the frame 50.

[0119] The fourth and fifth bus bar assemblies 130(4), 130(5) provide electrical connections between the batteries 200 on the second side of the battery array 202. The substrate 138 of the fourth and fifth bus bar assemblies 130(4), 130(5) is generally planar, covers the second side of the battery array and includes two α portions 140, wherein the β portion 150 is arranged between and coplanar with the α portions 140. The substrate 138 of the fourth and fifth bus bar assemblies 130(4), 130(5) has a uniform thickness. The fourth and fifth bus bar assemblies 130(4), 130(5) are arranged side by side in the same plane P5. The fourth and fifth bus bar assemblies 130(4), 130(5) are spaced apart in plane P5. Plane P5 is parallel to planes P1 and P2.

[0120] Reference Figure 22-26 and Fig.29 , the insulating layer 180 is arranged on the side 132 of the substrate 138 facing the battery terminals to be located between the α portion 140 of the five bus bar assemblies 130 (1), 130 (2), 130 (3), 130 (4), 130 (5) and the battery terminals 214, 216. The insulating layer 180 is electrically and thermally insulating. For example, in some embodiments, the insulating layer can have a dielectric breakdown voltage of 2.6 kV and can have a thermal conductivity of 0.17 W / mK, so that it can adapt to temperatures of at least 800 degrees Celsius without failure. In addition, the insulating layer 180 provides a flame barrier. For example, in some embodiments, when classified using the UL94 test method (e.g., the plastic flammability standard published by the Underwriters Laboratories of the United States), the insulating layer 180 has a flame retardant rating of V-0, 5VA.

[0121] The insulating layer 180 includes a secondary connection through hole 188. A secondary connection through hole 188 is provided for each battery 200 of the quadrant, and each secondary connection through hole 188 is aligned with the corresponding primary connection through hole 142, thereby exposing the end of the battery, so that an electrical connection can be made between the exposed battery terminal 214 or 216 and the α portion 140 using the electrical connector 160. The secondary connection through hole 188 is circular and has a diameter d4 that is smaller than the diameter d1 of the battery 200 and the diameter d2 of the main connection through hole 142. Since the diameter of the secondary connection through hole 188 is smaller than the diameter of the main connection through hole 142, an insulating boundary or edge is provided within each main connection through hole 142 to reduce the possibility of a short circuit between the substrate 138 and the battery terminals 214, 216 near the main connection through hole 142. The insulating layer 180 also includes a secondary flow hole 190 aligned with the mainstream through hole 144 and having the same diameter d3 as the mainstream through hole 144.

[0122] In some embodiments, the insulating layer 180 may be in the form of a sheet having a first side 182 facing the α portion 140 and a second side 184 facing the battery array 202. The sheet used to form the insulating layer 180 may be a paper sheet, a ceramic sheet, a paper sheet coated with ceramic, a film, or other suitable thin material. The first side 182 of the sheet-like insulating layer 180 may include an adhesive coating that fixes the insulating layer 180 to the α portion 140. In addition, the second side 184 of the insulating layer 180 may include an adhesive coating that fixes the insulating layer to the exposed battery end. For example, the first and second sides 182, 184 of the insulating layer 180 may include a pressure-sensitive adhesive coating. In other embodiments, the insulating layer 180 may be a coating disposed on (e.g., bonded to) the battery side 132 of the α portion 140 of the substrate 138. The coating may be applied to the surface by any suitable method, such as a sintering process or a vapor deposition process.

[0123] Reference Figure 27-28 For each battery terminal 214, 216, an electrical connector 160 extends between the battery terminal 214, 216 and the α portion 140 of the corresponding bus bar assembly 130(1), 130(2), 130(3), 130(4), 130(5) (e.g., the bus bar assembly facing the battery terminal) and provides an electrical connection. For example, the electrical connector 160 can be a welding wire, but is not limited to this type of electrical connector. As used herein, the term "welding wire" refers to an electrical connector in the form of a thin wire composed of high purity gold, aluminum or copper, which is attached to the substrate 138 at one end and attached to the terminal 214, 216 at the other end via a wire welding process. Other suitable electrical connectors can be used instead of welding wires depending on the needs of a specific application. For example, another suitable electrical connector can include direct welding between the battery terminal 214, 216 and the α portion 140 of the corresponding bus bar assembly 130(1), 130(2), 130(3), 130(4), 130(4), 130(5).

[0124] In the battery module 40, the positive terminal 214 of each battery 200 is connected to the α portion 140 ( Fig.28 ), the negative terminal of the battery 200 is connected to the α portion 140 ( Fig. 27). In the illustrated embodiment, the current carrying capacity of the first electrical connector 160(1) is different from the current carrying capacity of the second electrical connector 160(2), for example, the current carrying capacity of the electrical connectors 160(1), 160(2) is asymmetric. In particular, the current carrying capacity of the first electrical connector 160(1) is less than the current carrying capacity of the second electrical connector. By setting the first and second electrical connectors 160(1), 160(2) in which the current carrying capacity of the first electrical connector 160(1) is less than the current carrying capacity of the second electrical connector 160(2), each battery is electrically connected to the corresponding bus bar assembly 130, so that the electrical connection to the positive terminal 214 of the battery fails before the electrical connection to the negative terminal 216 of the battery, thereby disconnecting the internal circuit of the battery module 40.

[0125] In the illustrated embodiment, the difference in current carrying capacity between the first and second electrical connectors 160(1), 160(2) is achieved by providing a single bond wire as the first electrical connector 160(1) and providing two bond wires (e.g., a dual bond wire) as the second electrical connector 160(2), wherein each bond wire has the same current carrying capacity.

[0126] In other embodiments, the difference in current carrying capacity between the first and second electrical connectors 160(1), 160(2) can be achieved by providing a single first wire bond as the first electrical connector 160(1) and a single second wire bond as the second electrical connector 160(2), wherein the first wire bond has a lower current carrying capacity than the second wire bond. For example, this can be achieved by providing the first wire bond with a smaller diameter than the second wire bond.

[0127] In other embodiments, the difference in current carrying capacity between the first and second electrical connectors 160(1), 160(2) can be achieved by providing a single first weld wire as a direct weld between the first electrical connector 160(1) and the substrate 138 and the negative terminal 216 as the second electrical connector 160(2).

[0128] In other embodiments, the difference in current carrying capacity of the first and second electrical connectors 160(1), 160(2) can be achieved by providing a first conductive strip or lead as the first electrical connector 160(1) and a second conductive strip or lead as the second electrical connector 160(2), wherein the first conductive strip includes a fuse. For example, this can be achieved by providing the first conductive strip with a necked portion that fails at a lower current than the remainder of the conductive strip.

[0129] refer to Figure 8 and Figure 30-33, the frame 50, including the array 202 of batteries 200 supported therein, and the busbars 130 covering the battery ends 207, 208 and the cover and bottom plates 52, 54 of the frame 50, are arranged in the spacing structure 80. The spacing structure 80 is a strip-shaped rectangular thin-walled tube, which includes an open spacing structure first end 82, an open spacing structure second end 84 opposite to the spacing structure first end 82, and a spacing structure side wall 85 extending between the spacing structure first end 82 and the spacing structure second end 84.

[0130] The spacer structure side wall 85 has a rectangular shape when viewed toward the first or second end 82, 84 of the spacer structure, and thus includes four wall portions 86, 90, 94, 96. In particular, the spacer structure side wall 85 includes a first wall portion 86, a second wall portion 90 spaced apart from and parallel to the first wall portion 86, a third wall portion 94 perpendicular to the first wall portion 86 and connecting the first wall portion 86 to the second wall portion 90, and a fourth wall portion 96 spaced apart from and parallel to the third wall portion 94. The fourth wall portion 96 connects the first wall portion 86 to the second wall portion 90.

[0131] The first, second, third and fourth wall portions 86, 90, 94, 96 cooperate to define the spacing structure interior space 104. The frame 50 is arranged in the spacing structure interior space 104 so that the first wall portion 86 of the spacing structure 80 covers the α portion 140 of the first, second and third bus bar assemblies 130(1), 130(2), 130(3) on the first side of the battery array 202. In addition, the second wall portion 90 of the spacing structure 80 covers the α portion 140 of the fourth and fifth bus bar assemblies 130(4), 130(5) on the second side of the battery array 202. In this way, each of the battery first end 207 and the battery second end 208 faces the first wall portion 86 or the second wall portion 90. In addition, the first end cap and the second end cap 56, 58 of the frame are arranged in the first and second ends 82, 84 of the opening spacing structure.

[0132] The inner surface 88 of the first wall portion 86 and the inner surface 92 of the second wall portion 90 respectively include grooves 98 extending from the first end 82 of the spacing structure to the second end 84 of the spacing structure. The grooves 98 serve as fluid channels within the battery module 40, and the same engineering fluid used to inject the battery pack 1 is actively pumped through the grooves 98, as discussed further below. The number of grooves 98 provided on each of the first and second wall portions 86, 90 corresponds to the number of rows of batteries 200 in the battery array 202. Each groove 98 is aligned with a row of the battery array 202 and is open to the battery array 202, whereby the battery ends 207, 208 and the electrical connector 160 are exposed to the cooling effect of the engineering fluid flowing through the grooves 98. In other words, each groove 98 provides a coolant fluid channel 102 that flows between the spacing structure 80 and the battery array 202. To this end, the shape and size of the grooves 98 are designed to accommodate sufficient coolant fluid flow to keep the battery 200 at a desired temperature. In addition, the shape and size of the grooves 98 can be designed to accommodate airflow discharged from the battery 200. In the illustrated embodiment, each groove 98 has a rectangular shape when the spacing structure 80 is viewed in cross-section, wherein the bosses 100 are disposed between and separate adjacent grooves 98 .

[0133] The fluid enters each groove 98 at the spacing structure first end 82 and can exit the groove 98 at the spacing structure second end 84. The engineered fluid within the groove 98 flows through the positive and negative terminals of the battery including the electrical connector 160. In some embodiments, the electrical connector 160 is aligned with the flow direction (e.g., oriented parallel to the elongated direction of the groove 98), whereby fluid pressure loss in the fluid channel 102 due to the presence of the electrical connector 160 is minimized.

[0134] Because the battery pack 1 is filled with an engineered fluid, the components of the battery module 40, including the frame 50 and the spacing structure 80, are not fluid-tightly sealed with each other or with other components of the battery module 40. Although the fluid is directed through the fluid channel 102 defined by the groove 85, the fluid is not prevented from flowing through the battery module 40, including between the side walls 210 of adjacent batteries 200 and through the primary and secondary flow holes 144, 190 of the bus bar assembly 130 of the battery module 40.

[0135] The frame 50 and the spacing structure 80 are formed of a dielectric material, such as a polymer. The spacing structure 80 can be manufactured as a one-piece structure (not shown), or for ease of assembly with the frame 50, can be manufactured into two U-shaped halves 80(1), 80(2).

[0136] Reference Figure 4-5 and Figure 34-35As previously described, each cartridge 20 includes three battery modules 40(1), 40(2), 40(3) supported within a cartridge housing 22. The cartridge housing 22 includes a rigid U-shaped upper portion 24 and a rigid U-shaped lower portion 26 that cooperate to form a tubular cartridge housing 22 having an open end 23. In some embodiments, the upper portion 24 and the lower portion 26 are formed of steel.

[0137] Three battery modules 40(1), 40(2), 40(3) are arranged side by side in the box housing 22, and a partition 110 is arranged between each adjacent battery module 40. In particular, the first partition 110(1) is arranged between the first wall portion 86 of the first battery module 40(1) and the second wall portion 90 of the second battery module 40(2), and the second partition 110(2) is arranged between the first wall portion 86 of the second battery module 40(2) and the second wall portion 90 of the third battery module 40(3). In this configuration, the battery ends 207, 208 of the battery 200 of one battery module 40 face the battery ends 207, 208 of the battery 200 of the adjacent battery module 40. By placing the partition 110 between the corresponding wall portions 89, 90 of the adjacent modules 40(1), 40(2), 40(3), the partition 110 can serve as a thermal and mechanical barrier in the event of battery ventilation and / or thermal runaway of the battery 200 of one of the modules 40. To this end, the separator 110 is a rigid thin metal plate that is airtight and has a melting temperature above 1000 degrees C. In the embodiment shown, the separator 110 is a thin steel plate.

[0138] By means of a cylindrical retaining rod 28 ( Figure 5 ) prevents the battery modules 40(1), 40(2), 40(3) from leaving the box housing open end 23. The retaining rods 28 cooperate with the first grooves 76 of the first and second end covers 56, 58 of the frame and pass through the openings 118 along the periphery of the partitions 110(1), 110(2) to retain the battery modules 40(1), 40(2), 40(3) in the box housing 22.

[0139] The three battery modules 40(1), 40(2), 40(3) are arranged in the box housing 22 so that the battery module terminals 42, 44 protrude outward from the box housing 22. In addition, at each open end 23 of the box housing 22, the polarities of the three protruding battery module terminals 42, 44 alternate in polarity.

[0140] refer to Figure 36-40, the battery pack 1 includes a thermal management system 500 that actively directs an engineered fluid to each battery module 40 disposed in the battery pack housing 2. The thermal management system 500 includes a fluid pump 680, a fluid delivery line 682 that receives pressurized fluid from the fluid pump 680 and delivers it to the box 20, and a fluid return line 692 that collects fluid from the box 20 and returns it to the fluid pump 680. In the illustrated embodiment, the fluid pump 680 is located outside the battery pack housing 2, but in other embodiments, the fluid pump 680 can be disposed within the battery pack housing 2.

[0141] In the battery pack housing 2, the fluid delivery line 682 is divided into four delivery branch lines 684(1), 684(2), 684(3), 684(4). Each delivery branch line 684(1), 684(2), 684(3), 684(4) delivers the fluid to two adjacent boxes 20. To this end, each delivery branch line 684(1), 684(2), 684(3), 684(4) includes a first manifold portion 685(1) of the inlet gas collection assembly 502 that guides the fluid to the first of the adjacent boxes 20, and a second manifold portion 685(2) of the inlet gas collection assembly 502 that guides the fluid to the second of the adjacent boxes 20. The inlet gas collection assembly 502 of each box 20 is basically the same, and the inlet gas collection assembly 502 will be described in detail below. Each of the first and second manifold portions 685(1), 685(2) is a tube having an inlet end 686, an opposite outlet end 687, and three delivery ports 688. The inlet end 686 of the first manifold portion 685(1) is connected to a corresponding branch line 684 of the fluid delivery line 682, and the outlet end 687 of the first manifold portion 685(1) is connected to the inlet end 686 of the second manifold portion 685(2). The outlet end 687 of the second manifold portion 685(2) is covered (e.g., plugged). The three delivery ports 688 are respectively connected to the inlet openings 522 of the corresponding inlet gas collection assemblies 502, and provide the fluid to the inlet gas collection assemblies 502 in parallel.

[0142] Each delivery port 688 may include an orifice balancer 690 ( Figures 44-46 The orifice balancer 690 is a ring disposed within the delivery port 688, and the size of the inner surface 692 of the orifice balancer 690 determines the flow rate through the delivery port 688. By appropriately selecting the size of the orifice balancer 690, the fluid flow rate of the delivery port 688 can be controlled and adjusted.

[0143] Each box 20 includes an outlet plenum assembly 582 having an outlet opening 622 and an outlet line 626. The outlet plenum assembly 582 of each box 20 is substantially identical and will be described in detail below. The outlet line 626 from each box 20 is connected to one of two return branch lines 694, which merge into the fluid return line 692.

[0144] Reference Figures 41-48 The inlet plenum assembly 502 closes one of the two open ends 23 of the box housing 22 and guides the fluid to each battery module 40(1), 40(2), 40(3) arranged in the box 20. The inlet plenum assembly 502 includes an inlet plenum chamber 504 and an inlet flow divider 540 arranged between the inlet plenum 504 and each battery module 40(1), 40(2), 40(3).

[0145] The inlet plenum assembly 502 simultaneously distributes fluid to each battery module 40(1), 40(2), 40(3) of the cartridge 20. To this end, the inlet plenum 504 and the inlet diverter 540 have fluid channels 102 that cooperate to simultaneously direct fluid to the spacer structure 80 disposed in each battery module 40(1), 40(2), 40(3), as will now be described.

[0146] The inlet plenum 504 includes an end plate 506 parallel to the end caps 56, 58 of the frame 50 and an edge 514 protruding from the module-facing surface 508 of the end plate 506. The edge 514 extends along a portion of the outer periphery 512 of the end plate 506. In the illustrated embodiment, the end plate 506 has a rectangular profile, and the edge 514 extends along three sides of the end plate 506. In use, the edge 514 covers the cassette housing 22. In addition, the inlet plenum 504 includes a pair of guide rails 518 protruding from the module-facing surface 508 of the end plate 506. The guide rails 518 extend linearly parallel to the first and second wall portions 86, 90 of the frame. The guide rails 518 are aligned with each baffle 110, so that they are configured to receive the fluid diverted from the inlet diverter 540 and guide it to the fluid channel 102.

[0147] The end plate 506 of the inlet plenum includes three fluid inlet openings 522 that are connected to the fluid delivery port 688 of the manifold portion 685 and receive fluid from the fluid delivery line 682. The fluid inlet openings 522 are arranged in a linear row, and the track 518 is arranged between each adjacent fluid inlet opening 522. Each fluid inlet opening 522 faces a corresponding one of the three battery modules 40(1), 40(2), 40(3) of the box 20. In addition, each fluid inlet opening 522 is centered on the end cap 56, 68 of the frame 50 of the corresponding battery module 40 and is aligned with the surface of the inlet diverter 540, as further discussed below.

[0148] Each fluid inlet 522 is surrounded by a necked boss 524 that projects outwardly from the outwardly facing surface 516 of the end plate 506. The boss 524 is shaped and sized to be received in the delivery port 688 and to form a mechanical connection therewith. For example, the boss 524 may be press-fit connected to the delivery port 688. The orifice balancer 690 ( Figures 44-46 ) is arranged in the output port 688 and is sandwiched between the inner surface of the output port 688 and the terminal end 526 of the necking boss 524. As previously described, the orifice balancer 690 enables the inlet plenum assembly 502 to provide fluid to one of the battery modules (e.g., the first battery module 40(1)) at a first fluid flow rate and to another of the battery modules (e.g., the second battery module 40(2)) at a second fluid flow rate, wherein the first fluid flow rate is different from the second fluid flow rate. This is achieved by providing an orifice balancer of appropriate size in the delivery port 688.

[0149] The inlet plenum end plate 506 includes a snap-fit ​​clip 528 that projects outwardly from the end plate outwardly facing surface 516. The clip 528 receives and supports one of the first and second manifold portions 685(1), 685(2).

[0150] An inlet diverter 540 is provided for each battery module 40(1), 40(2), 40(3) of the box 20 and is arranged between the end plate 506 of the inlet plenum and the frame end caps 56, 58 of the corresponding battery modules 40(1), 40(2), 40(3). The inlet diverter 540 is a molded rigid plate configured to receive fluid leaving the fluid inlet opening 522 and divert the fluid to the fluid channel 120 of the corresponding battery module 40(1), 40(2), 40(3). The inlet diverter 540 includes a flat first portion 548 adjacent to the outer periphery 546 of the inlet diverter 540, and a dome-shaped (e.g., bulging) second portion 550 surrounded by the first portion 548. The first portion 548 is parallel to the end plate 506. The second portion 550 protrudes toward the end plate 506 and is aligned with the fluid inlet opening 522. In the illustrated embodiment, the first portion 548 of the inlet diverter 540 is secured to the end caps 56, 58 of the frame 50 of the respective battery module 40(1), 40(2), 40(3) together with the end plate 506. In the illustrated embodiment, fasteners such as screws 522 are used to secure the diverter 540 and the end plate 506 to the frame 50, and the fastener openings in the end plate 506 are surrounded by spacers 530 that provide spacing between the end plate 506 and the diverter 504. The inlet diverter 540 diverts the fluid toward the fluid channel 120 while diverting the fluid away from the first and second grooves 76, 78 disposed in the outwardly facing surfaces of the respective frame end caps 56, 58.

[0151] refer to Figure 49-54, the outlet gas collection assembly 582 closes the other of the two open ends of the box housing 22. That is, the outlet gas collection assembly 582 and the inlet gas collection assembly 502 are arranged at opposite ends of the box housing 22. The outlet gas collection assembly 582 collects the fluid discharged from the groove 98 (e.g., fluid channel 102) of the spacing structure 80 of the battery module. The outlet gas collection assembly 582 includes an outlet gas collection chamber 584 and an outlet diverter 640 arranged between each battery module 40 (1), 40 (2), 40 (3) and the outlet gas collection chamber 584. The outlet gas collection chamber 584 is similar to the inlet gas collection chamber 504. For this reason, the same figure numbers are used to refer to the same elements, and the description of the common elements is not repeated. The difference between the outlet gas collection chamber 584 and the inlet gas collection chamber 504 is that the inlet opening 522, the necking boss 524 and the guide rail 518 are omitted. In addition, the outlet plenum includes a single outlet opening 622, which is arranged on the outwardly facing surface of the edge 514 and is in fluid communication with the space within the outlet plenum 584. The outlet flow divider 640 is the same as the inlet flow divider 540. Likewise, the same reference numerals are used to refer to the same elements. The outlet plenum assembly 582 allows the fluid of each fluid channel 120 leaving the spacing structure 80 to be collected in the outlet plenum 584 and directed to the outlet opening 622. The outlet opening 622 is connected to the fluid return line 692 via an outlet line 626 and a return branch line 694.

[0152] Reference Figures 55-60 The battery pack 1 includes a pressure management system 300 that provides passive management of pressure within a sealed battery pack housing 2. The pressure management system 300 may be advantageous, for example, when the engineering fluid has a high coefficient of expansion and may be sensitive to temperature and / or altitude changes. The pressure management system 300 includes at least one flexible and expandable pressure compensation device 330 disposed within the battery pack housing 2, a vent block 302 disposed on an outer surface of the battery pack housing 2, and fittings 380, 480 that provide fluid communication between the pressure compensation device 330 and the vent block 302.

[0153] In the illustrated embodiment, the pressure compensation device 330 is a set of independent, series-connected flexible, expandable bladders 340. The bladders 340 act like lungs in that the bladders 340 expand or contract to accommodate changes in the volume of the engineered fluid within the sealed battery pack housing 2, such as changes caused by pressure and temperature conditions surrounding the battery pack housing 2. The bladders 340 are a set of three independent bladders 340(1), 340(2), 340(3) that are connected in series by primary and secondary fittings 380, 480. The first bladder 340(1) is connected to the vent block 302 via the primary fitting 380 and is in fluid communication therewith, and is connected to the second bladder 340(2) via the same primary fitting 380 and is in fluid communication therewith. The second bladder 340(2) is also connected to the third bladder 340(3) via the secondary fitting 480 and is in fluid communication therewith.

[0154] Each bladder 340(1), 340(2), 340(3) is a closed bag formed of a gas and moisture impermeable material that is flexible enough to allow the bladder 340 to expand and contract. In addition, each bladder 340(1), 340(2), 340(3) is flexible enough to generally conform to the shape of adjacent structures within the battery pack 1, including the inner surface of the battery pack housing 2, the outer surfaces of the box housing 22 disposed in the battery pack housing 2, and other auxiliary structures.

[0155] In the illustrated embodiment, each capsule 340(1), 340(2), 340(3) is formed of a laminate having a metal film layer and a polymer layer. In one example, the laminate may have three layers, including an outer metal film layer, a middle polyethylene terephthalate (PET) film layer, and an inner polypropylene film layer. In another example, the laminate may have three layers, including an outer PET film layer, a middle metal foil layer, and an inner polypropylene film layer.

[0156] The number of capsules 340 and the size of each capsule 340 depends on the requirements of the specific application. In the embodiment shown, the capsules 340(1), 340(2), 340(3) each have a unique shape and size, and their shape and size are adapted to the available space within the battery pack 1 to accommodate the cartridges 20. The cartridges 20 are arranged in a single layer within the battery pack container 4 and are divided into two groups. The two groups of cartridges 20 are separated by a gap 9 ( Figure 2 , Fig.36 ) are separated by a gap that receives fluid delivery and return lines 682, 692 of a thermal management system and other auxiliary structures and devices (not shown). The bladders 340(1), 340(2), 340(3) are arranged in the battery pack housing 2 around the box 20, as discussed in detail below.

[0157] The first capsule 340(1) is larger than the second and third capsules 340(2), 340(3) and is arranged between the box 20 and the lid 6. The first capsule 340(1) can be formed, for example, by stacking a stacked first sheet 341 with a stacked second sheet 342 and sealing the periphery of the first and second sheets 341, 342 along a sealing line 348(1) to form a closed first internal space 358(1). The peripheral edge 356(1) can be sealed, for example, by heating. The first capsule 340(1) has a length and width sufficient to cover each of the eight boxes 20 and has a very flat cross-section. In other words, the height h1 of the first capsule 340(1) is very small relative to its length l1 and / or width w1, wherein the height h of each capsule 340 is parallel to the height hp of the battery pack housing 2. For example, when the first bladder 340(1) is not inflated, the height h1 of the first bladder 340(1) may correspond to approximately the thickness of the two sheets 341, 342 of material used to form the first bladder 340(1).

[0158] The first bladder 340(1) includes a first opening 351 formed in the first sheet 341 at a location spaced apart from the seal line 348(1) of the first bladder 340(1). The first opening 351 is shaped and sized to receive the first portion 440 of the primary accessory 380 therethrough, and the first sheet 341 is sealed to the first portion 440 of the primary accessory 380 at the first opening 351.

[0159] The first bladder 340(1) includes a second opening 352 formed in the second sheet 342 at a location spaced apart from the seal line 348(1) of the first bladder 340(1). The second opening 352 is aligned with the first opening 351 in a direction parallel to the height hi. In addition, the second opening 352 is shaped and sized to receive the second portion 442 of the primary accessory 380 therethrough, and the second sheet 342 is sealed with the second portion 442 of the primary accessory 380 at the second opening 352.

[0160] In addition, the first bladder 340(1) includes a pair of sealed through holes 358 at locations spaced apart from the outer periphery 356 of the bladder. The through holes 358 allow auxiliary components of the battery pack 1 to pass through the first bladder 340(1). For example, in the illustrated embodiment, the through holes 358 allow a fill tube to pass through the first bladder 340(1). In the illustrated embodiment, the through holes 358 are arranged near the first and second openings 351, 352, such that one through hole 358 is arranged on each opposite side of the first and second openings 351.

[0161] The second capsule 340(2) is arranged in the gap 9 between the two sets of boxes 20 and is located relative to Figure 1The orientation of the battery pack 1 shown is located below the first bladder 340(1). Compared to the first bladder 341(1), the bladder 340(2) has an irregular shape, a relatively high profile, and a width corresponding to the width of the gap in which it is located. For example, the second bladder 340(2) can be formed by stacking a stacked third sheet 343 with a stacked fourth sheet 344 and sealing the outer periphery 356(2) of the third and fourth sheets 343, 344 along a sealing line 348(2) to form an enclosed second interior space 358(2). The outer periphery 356(2) can be sealed, for example, by heating. The second bladder 340(2) includes a third opening 353 formed in the third sheet 343 at a position spaced apart from the sealing line 348(2) of the second bladder 340(2). The third opening 353 is shaped and sized to receive the third portion 446 of the primary accessory 380 therethrough, and the third sheet 343 is sealed with the third portion 446 of the primary accessory 380 at the third opening 353 .

[0162] In addition, the second bladder 340(2) includes a fourth opening 354 formed in the third sheet 343 at a location spaced apart from the seal line 348(2) of the second bladder 340(2). The fourth opening 354 is located at an opposite end of the second bladder 340(2) relative to the third opening 353. The fourth opening 354 is shaped and sized to receive one end 481 of the secondary fitting 480, and the third sheet 343 is sealed to the one end of the secondary fitting 480 at the fourth opening 354.

[0163] The third capsule 340(3) is arranged in the gap 9 between the two groups of boxes 20 and is adjacent to (e.g., connected end to end) the second capsule 340(2) in the gap 9. Similar to the capsule 340(2), the third capsule 340(3) is located below the first capsule 340(1). The third capsule 340(3) has a generally rectangular shape, and its width corresponds to the width of the gap in which it is located. The height of the third capsule 340(3) is lower than the second capsule 340(2). For example, the third capsule 340(3) can be formed by stacking a laminated fifth sheet 345 with a laminated sixth sheet 346, and sealing the outer peripheral edges 356(3) of the fifth and sixth sheets 345, 346 along a sealing line 348(3) to form a closed third internal space 358(3). The outer peripheral edges 356(3) can be sealed, for example, by heating. The third bladder 340(3) includes a single opening, such as a fifth opening 355 formed in the fifth sheet 345 at a location spaced apart from the seal line 348(3) of the third bladder 340(3). The fifth opening 355 is shaped and sized to receive the opposite end 482 of the secondary fitting 480, and the fifth sheet 345 is sealed to the opposite end 482 of the secondary fitting 480 at the fifth opening 355.

[0164] refer to Figures 61-64The vent block 302 is in fluid communication with the interior spaces 358(1), 358(2), 358(3) of the pressure compensation device 330 and allows the interior spaces to communicate with the atmosphere surrounding the battery pack 2. The vent block 302 is a rectangular structure that is arranged on the outer surface of the battery pack cover 6. The vent block 302 includes an end 304 facing the cover, an outwardly facing end 306 opposite to the end 304 facing the cover, and four sides 308, 310, 312, 314 extending between the end 304 facing the cover and the outwardly facing ends 304, 306. The vent block 302 includes a longitudinal hole 318 that opens at the end 304 facing the cover. The longitudinal hole 318 terminates in the vent block 302. The longitudinal hole 318 is threaded and engages with corresponding threads of the first end 381 of the first fitting 380, as further discussed below.

[0165] The vent block 302 includes a first transverse hole 322 that is perpendicular to the longitudinal hole 318 and intersects the longitudinal hole 318. The first transverse hole 322 opens on the opposite first and third sides 308, 312 of the vent block 302. The opening 324 of the first transverse hole 322 on the first side 308 of the vent block is closed by a one-way valve 336. When closed, the one-way valve 336 is impermeable to air and liquid. The one-way valve 336 opens at a predetermined pressure, allowing fluid (e.g., air) to be released from the pressure management system 300. In one example, the one-way valve can be an umbrella valve. The opening 326 of the first transverse hole 322 on the third side 312 of the vent block is closed by a first plug 333 that is impermeable to fluid.

[0166] The vent block 302 includes a second transverse hole 328 that is perpendicular to and intersects the longitudinal hole 318 and the first transverse hole 322. The second transverse hole 328 opens at the opposite second and fourth sides 310, 314 of the vent block 302. The opening 332 of the second transverse hole 328 on the second side 310 of the vent block is closed by a breathable membrane 338. The breathable membrane 338 allows air to pass through but prevents liquid from passing through. In one example, the vent membrane 338 can be a polytetrafluoroethylene (PTFE) membrane. The opening 334 of the second transverse hole 328 on the fourth side 314 of the vent block is closed by a second plug 335 that is impermeable to fluid.

[0167] The longitudinal aperture 318 and the first and second transverse apertures 322 , 328 together define an interior space 316 within the vent block 302 .

[0168] A cap 339 having a generally cup shape covers the outwardly facing end 306 and sides 308, 310, 312, 314 of the vent block. The cap 339 is secured to the outwardly facing end 306 of the vent block via fasteners. The cap 339 is spaced apart from the sides 308, 310, 312, 314 of the vent block to ensure good ventilation while protecting the one-way valve 336 and the breathable membrane 338 from debris and / or damage.

[0169] refer to Fig.65 and Fig.66 , the primary fitting 380 provides fluid communication between the interior space 316 of the vent block 302 and the first interior space 358(1) defined by the first bladder 340(1). In addition, the primary fitting 380 provides fluid communication between the first interior space 358(1) and the second interior space 358(2) defined by the second bladder 340(2). The secondary fitting 480 provides fluid communication between the second interior space 358(2) and the third interior space 358(3) defined by the third bladder 340(3). The primary and secondary fittings 380, 480 will now be described in detail.

[0170] The main fitting 380 provides fluid communication between the interior space 316 of the vent block, the interior space 358(1) of the first bladder 340(1), and the interior space 358(2) of the second bladder 340(2). The main fitting 380 is a strip-shaped tube that includes a first open end 381 connected to the vent block 302 and a second open end 382 opposite the first end 381 and arranged in the second bladder 340(2). The first end 381 of the main fitting has an external thread that engages with a corresponding thread of the longitudinal hole 318 of the vent block. The main fitting 380 includes a side wall 387 extending between the first and second ends 381, 382. The inner surface of the side wall 387 provides a longitudinal fluid channel 388. The longitudinal fluid channel 388 extends between the first and second ends 381 of the main fitting 380, thereby providing fluid communication between the interior space 316 of the vent block 302 and the second interior space 358(2). The main fitting 380 includes a first transverse fluid channel 400 that is perpendicular to and intersects the longitudinal fluid channel 388 and opens at the first side wall opening 452 (1) on the opposite side of the side wall 387. In addition, the main fitting 380 includes a second transverse fluid channel 450 that is perpendicular to the longitudinal fluid channel 388 and the first transverse fluid channel 400. The second transverse fluid channel 450 intersects the longitudinal fluid channel 388 and the first transverse fluid channel 400 and opens at the second side wall opening 452 (2) on the opposite side of the side wall 387. In use, the main fitting 380 extends through the first bladder 340 (1), wherein the first and second side wall openings 452 (1), 452 (2) are arranged in the first interior space 358 (1). The first and second transverse fluid channels 400, 450 provide fluid communication between the interior space 316 of the vent block 302 and the first interior space 358 (1).

[0171] The main fitting 380 includes a first portion 440 disposed between the first and second sidewall openings 452(1), 452(2) and the first end 381 of the main fitting 380. The first portion 440 corresponds to the position where the main fitting 380 is fluidly sealed to the first opening 351 of the bladder. The first portion 440 includes a first flange 402 disposed in the first interior space 358(1) and facing the inner surface of the first sheet 341, and a first threaded portion 403 (threads not shown) protruding through the first opening 351. In addition, the first portion 440 includes a first sealing assembly 404 that secures the first sheet 341 to the first flange 402 with a fluid-tight seal. The first sealing assembly 404 includes a resilient flat washer-shaped gasket 406, a flat washer 408, and a nut 410. The gasket 406 is disposed between the first sheet 341 and the first flange 402. The nut 410 engages the first threaded portion 403 and secures the flat washer 408 against the outwardly facing surface of the first sheet 341 , whereby the first sheet 341 and the washer 406 are sandwiched between the first flange 402 and the nut 410 .

[0172] The first portion 440 has a larger diameter than the diameter of the first end 381 of the main fitting, thereby providing a shoulder 384 at the transition between the two diameters. In use, the main fitting 380 is arranged in the battery pack housing 2 with the first end 381 protruding through an opening in the battery pack housing cover 6. The first end 381 is received within the longitudinal hole 318 of the vent block and engages the threads of the longitudinal hole of the vent block so that the shoulder 384 engages the inner surface of the cover 6 via an intervening gasket. Thus, the main fitting 380 and the vent block 302 cooperate to secure the main fitting 380 and the vent block 302 to the battery pack housing 2.

[0173] In addition, the main accessory 380 includes a second portion 442 disposed between the first and second sidewall openings 452(1), 452(2) and the second end 382 of the main accessory 380. The second portion 442 corresponds to the position where the main accessory 380 is fluidly sealed to the second opening 352 of the bladder. The second portion 442 includes a second flange 412 disposed in the first interior space 358(1) and facing the inner surface of the second sheet 342, and a second threaded portion 413 (threads not shown) protruding through the second opening 352. In addition, the second portion 442 includes a second sealing assembly 414 that secures the second sheet 342 to the second flange 412 with a fluid-tight seal. The second sealing assembly 414 is substantially similar to the first sealing assembly 404, and like elements are represented by like reference numerals. In the second sealing assembly 414, a gasket 406 is disposed between the second sheet 342 and the second flange 412. Additionally, the nut 410 engages the second threaded portion 413 and secures the flat washer 408 against the outwardly facing surface of the second sheet 342 , whereby the second sheet 342 and the washer 406 are sandwiched between the second flange 402 and the nut 410 .

[0174] The main fitting includes a third portion 466 disposed between the second portion 442 and the second end 382 of the main fitting. The third portion 466 includes a shank 468 extending between the second portion 442 and the second end 382 of the main fitting, and a collar 463 surrounding the shank 468. The shank 468 has no external threads and includes a pair of O-rings 461, 462 ( Fig.61 , Fig.64). Each sealing ring 461, 462 is arranged in an annular groove 467, 469 to protrude outwardly relative to the surface of the handle 468. The sealing rings 461, 462 are spaced longitudinally. The collar 463 has an inner surface 464, which has no internal threads and engages the handle 468 by a sliding fit connection, in which the sealing rings 461, 462 are compressed. In this way, the connection between the collar 463 and the handle 468 is also fluid-impermeable. The collar 463 has a threaded outer surface (the threads are not shown). In addition, the collar 463 has a distal end 465 covering the second end 382 of the main accessory. The distal end 465 of the collar includes a third flange 422. The third flange 422 is arranged in the second internal space 358 (2) and faces the inner surface of the third sheet 343, and the threaded portion of the collar 463 protrudes through the third opening 353 (for example, the opening at the proximal end of the second bladder 340 (2)). In addition, the third portion 466 includes a third sealing assembly 424 that secures the third sheet 343 to the third flange 422 with a fluid-tight seal. The third sealing assembly 424 is substantially similar to the first sealing assembly 404, and like elements are indicated by like reference numerals. In the third sealing assembly 424, a gasket 406 is disposed between the third sheet 343 and the third flange 422. In addition, a nut 410 engages the threaded outer surface of the collar 463 and secures the flat washer 408 relative to the outwardly facing surface of the third sheet 343, whereby the third sheet 343 and the gasket 406 are sandwiched between the third flange 422 and the nut 410. In this configuration, the second end 382 of the main fitting is disposed in the interior space 382 of the second bladder 340 (2), whereby the interior space 382 of the second bladder 340 (2) is in fluid communication with the vent block 302 via the longitudinal fluid passage 388.

[0175] refer to Fig.55 , Fig.56 and Fig.60 , the secondary fitting 480 includes a flexible tube extending between a fourth opening 354, which is an opening at the distal end of the second bladder 340(2), and a fifth opening 355, which is an opening at the proximal end of the third bladder 340(3). Each of the opposite ends 481, 482 of the secondary fitting 480 includes a flat-shaped connector 483 that is mechanically connected to a mating flat-shaped connector disposed in each of the fourth and fifth openings 354, 355. The connectors 483, 484 mechanically engage and provide a fluid-impermeable connection.

[0176] As previously described, the bladders 340(1), 340(2), 340(3) are flexible so as to expand or contract to accommodate changes in fluid volume due to pressure and temperature conditions surrounding the battery pack housing 2. When expanding or contracting, the bladders 340(1), 340(2), 340(3) move relative to the inner surface of the battery pack housing 2, the box 20, and other auxiliary components arranged within the battery pack housing 2. In some embodiments, the bladders 340(1), 340(2), 340(3) are provided with a fluid-permeable protective structure to reduce damage to the bladders when the bladders 340(1), 340(2), 340(3) expand and contract within the battery pack housing 2. For example, the battery pack 1 may include a protective mesh 830( disposed between the first bladder 340(1) and the box 20. Fig.56 In another example, the battery pack 1 may include a support shell 800 ( Fig.60 In the illustrated embodiment, the support shell 800 is used to protect the second and third bladders 340 ( 2 ), 340 ( 3 ).

[0177] Each support shell 800 includes a first half shell 801 and a second half shell 802 that can be separated from the first half shell 801. In cross section, each of the first half shell 801 and the second half shell 802 is generally U-shaped. The first half shell 801 and the second half shell 802 are open toward each other, and the open end 803 of the second half shell 802 is partially arranged in the open end 804 of the first half shell 801. In this way, the first half shell 801 and the second half shell 802 cooperate to form a segmented hollow structure, wherein the first half shell 801 can move freely relative to the second half shell 802. That is, although the second half shell 802 is partially arranged in the first half shell 801, the first half shell and the second half shell 801, 802 are only loosely engaged and not fixed to each other. In this way, the support shell 800 is fluid permeable to promote the complete exposure of the capsules 340 (2), 340 (3) to the engineering fluid that fills the battery pack housing 2.

[0178] The first and second half shells 801 , 802 include openings or cutouts 806 that allow the fittings 380 , 480 to pass therethrough.

[0179] In the illustrated embodiment, the pressure compensating device 330 is a group of bladders 340 connected in series. However, the pressure compensating device 330 is not limited to a group of bladders 340 connected in series. For example, in some embodiments, the pressure compensating device 330 can be a single bladder. The number of bladders used and the shape and size of the bladders used are determined by the requirements of the specific application. In addition, the pressure compensating device 330 is not limited to being a flexible, expandable bladder 340. In other embodiments, the bladder 340 can be replaced with one or more pistons or other suitable devices.

[0180] Although the battery pack 1 is described above as being configured to provide relatively high voltage power to a vehicle powertrain, the battery pack 1 is not limited to high voltage applications. For example, the battery pack 1 may be employed in low voltage applications, such as by reducing the number of battery modules and / or the number of batteries within the modules. In another example, the battery pack 1 may be used to provide power to devices other than the vehicle, such as an environmental control device, etc.

[0181] Although the positive electrode 218 is described herein as being electrically connected to the cover portion 205 and the negative electrode 220 is described as being electrically connected to the container portion 204, it should be understood that the battery 200 may alternatively be configured such that the positive electrode 218 is electrically connected to the container portion 204 and the negative electrode 220 is electrically connected to the cover portion 205.

[0182] In the above-mentioned battery module 40, the positive terminal 214 of each battery 200 is connected to the α portion 140 of one busbar assembly via the first electrical connector 160(1), and the negative terminal 216 of the battery 200 is connected to the α portion 140 of another busbar assembly via the second electrical connector 160(2). In the battery module 40, the battery 200 is configured such that the positive terminal 214 of the battery corresponds to the cover portion 205 of the battery, and the negative terminal 216 of the battery corresponds to the container portion 204 of the battery. However, it should be understood that the battery 200 is not limited to this configuration. For example, in some embodiments, the battery of the alternative embodiment is configured such that the positive terminal 214 of the battery corresponds to the container portion 204 of the battery, and the negative terminal 216 of the battery corresponds to the cover portion 205 of the battery. In the battery module including the battery of the alternative embodiment, the first and second electrical connectors 160(1), 160(2) can be configured such that the current carrying capacity of the first electrical connector 160(1) is greater than the current carrying capacity of the second electrical connector 160(2).

[0183] Although the current carrying capacity of the electrical connectors 160(1) and 160(2) is asymmetric in the above embodiment, the battery module 40 is not limited to this configuration. For example, in other embodiments, the current carrying capacity of the first electrical connector 160(1) is the same as the current carrying capacity of the second electrical connector 160(2), for example, the current carrying capacity of the electrical connectors 160(1) and 160(2) is symmetric.

[0184] Selective illustrative embodiments of battery modules and current collectors are described in detail above. It should be understood that only structures that are considered necessary to illustrate the battery modules and current collectors are described herein. It is assumed that other conventional structures, as well as structures of auxiliary and auxiliary components of battery modules and current collectors, are known and understood by those skilled in the art. In addition, although working examples of battery modules and current collectors have been described above, the battery modules and current collectors are not limited to the above working examples, but various design changes can be made without departing from the device as described in the claims.

Claims

1. A battery pack, comprising: a battery pack housing comprising a container and a cover, the cover closing an open end of the container and being joined to the open end of the container via a fluid-impermeable seal, the battery pack housing being filled with a dielectric first fluid; as well as A battery module arranged in the battery pack housing, the battery module comprising: a module housing that is fluid permeable and includes a fluid passage, a plurality of electrochemical cells disposed in the module housing such that cell terminals are exposed to a fluid disposed in the fluid passage, and A thermal management system, the thermal management system comprising: an inlet plenum assembly disposed at a first end of the battery module, the inlet plenum assembly comprising an inlet plenum chamber and an inlet diverter disposed between the inlet plenum chamber and the module housing; an outlet plenum assembly disposed at a second end of the battery module, wherein the second end is opposite the first end, the outlet plenum assembly comprising an outlet plenum chamber; and A fluid pump directs fluid to the inlet plenum assembly via a fluid delivery line and receives fluid from the outlet plenum assembly via a fluid return line.

2. The battery pack according to claim 1, wherein: The inlet plenum and the inlet diverter have features that cooperate to direct fluid to the fluid passage.

3. The battery pack according to claim 1, wherein: The inlet plenum chamber includes an end plate, an edge protruding from a first side of the end plate and extending along a portion of an outer periphery of the end plate, and a track protruding from the first side of the end plate, the track being configured to receive fluid diverted from the inlet diverter and guide the fluid to the fluid channel.

4. The battery pack according to claim 1, wherein: The inlet plenum includes a fluid inlet opening that receives fluid from the fluid delivery line and is aligned with a surface of the inlet diverter, Each battery includes a first end, a second end, and a sidewall extending between the first end and the second end, wherein the second end is opposite to the first end and the polarity of the first end is opposite to the polarity of the second end, The fluid passage is disposed between a first end of a given battery and an inner surface of the module housing, The inlet flow diverter is disposed between the inlet plenum and a side wall of a given cell and is configured to divert fluid exiting the fluid inlet opening toward the fluid passage.

5. The battery pack according to claim 1, wherein: The inlet splitter includes a flat first portion adjacent to an outer periphery of the inlet splitter, and a dome-shaped second portion surrounded by the first portion, the dome-shaped second portion protruding toward the inlet plenum, and The inlet plenum includes a fluid inlet opening that receives fluid from the fluid delivery line and is aligned with a second portion of a surface of the inlet flow splitter.

6. The battery pack according to claim 1, wherein: Each battery includes a first end having a first terminal, a second end having a second terminal, and a sidewall extending between the first end and the second end, wherein the second end is opposite to the first end and the polarity of the first terminal is opposite to the polarity of the second terminal, The module housing comprises: a tubular spacer structure comprising an open spacer structure first end, an open spacer structure second end opposite the spacer structure first end, and a spacer structure sidewall extending between the spacer structure first end and the spacer structure second end, and a frame configured to support the batteries in the battery module, the frame surrounding the batteries in a manner of covering the battery side wall of each battery and exposing the battery first end and the battery second end of each battery, the frame being arranged in the inner space of the spacing structure so that each battery first end and each battery second end face a corresponding one of the first wall portion and the second wall portion, respectively; Wherein, the inlet diverter is fixed to a portion of the frame.

7. The battery pack according to claim 6, wherein: The inlet diverter is fixed to the frame together with the inlet plenum, and the inlet plenum includes a spacer that keeps a spacing between the inlet diverter and a surface of the inlet plenum facing the module.

8. The battery pack according to claim 1, wherein: The battery modules include a first battery module and a second battery module, and the inlet plenum assembly distributes fluid to the first battery module and the second battery module simultaneously.

9. The battery pack according to claim 8, wherein: The inlet plenum assembly is configured to provide fluid to the first battery module at a first fluid flow rate and to provide fluid to the second battery module at a second fluid flow rate, wherein the first fluid flow rate is different from the second fluid flow rate.

10. The battery pack according to claim 9, wherein: The inlet plenum chamber comprises: a first fluid inlet opening that receives fluid from the fluid delivery line and is aligned with the first battery module, and a second fluid inlet opening that receives fluid from the fluid delivery line and is aligned with the second battery module, And wherein the first fluid inlet opening has a different diameter than the second fluid inlet opening.

11. The battery pack according to claim 1, wherein: The outlet plenum assembly includes an outlet flow splitter disposed between the outlet plenum and the module housing.

12. The battery pack according to claim 1, wherein: The outlet plenum is devoid of fluid flow guide tracks.

13. The battery pack according to claim 1, wherein: The battery module is comprised of a plurality of battery modules, each battery module comprising a corresponding module housing; and The thermal management system is configured to circulate the first fluid through a module housing of each battery module and to provide fluid to a given battery module at a fluid flow rate that is different than a fluid flow rate to other battery modules of the battery pack.

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