conductive plate

Abstract

An electrically conductive plate is provided that is configured to be electrically connected with each of a first plurality of electric cells. The plate includes a vent passage formed in the plate. The vent passage is arranged to be in fluid communication with a vent port of each of the electric cells when the plate is connected to the electric cells in use to provide a fluid path between the vent port of each of the electric cells and a space outside of the electric cells.

Description

Technical Field

[0001] The present invention relates to a conductive plate configured to be electrically connected to each of a first group of multiple battery cells, and particularly, but not limited to, a conductive plate for suppressing or preventing heat diffusion within a battery pack. Background Technology

[0002] Battery packs for electric vehicles are typically made using rechargeable cells, including lithium-ion cells and lithium iron phosphate cells. These cells can be connected in series and / or in parallel to meet the vehicle's voltage, power, and energy requirements.

[0003] When using rechargeable battery cells, there is a risk of thermal runaway events caused by the negative and positive electrode materials coming into contact with each other. This is usually due to mechanical failure of the separator that separates the negative and positive electrode materials. Causes of failure may include manufacturing defects, improper battery management (including overcharging and short circuits), and overheating.

[0004] In a thermal runaway event, the cell temperature can rapidly exceed 1500°C, and a large amount of hydrocarbon gas is released under pressure. This can cause surrounding or adjacent cells in the battery pack to overheat and also enter thermal runaway, thus allowing thermal runaway to propagate throughout the battery pack.

[0005] The present invention was conceived in view of the above circumstances. Summary of the Invention

[0006] According to a first aspect, a conductive plate is provided, configured to be electrically connected to each of a first group of multiple battery cells. The plate may include venting channels formed therein. The venting channels may be arranged or positioned such that, when the plate is connected to the battery cells in use, the venting channels are configured to be in fluid communication with the vent of each battery cell to provide a fluid passage between the vent of each battery cell and a space outside the battery cell.

[0007] This allows gases from a faulty cell to escape into the external environment without overheating other cells, thus suppressing or preventing thermal runaway propagation to other cells. Suppressing or preventing the propagation of thermal runaway between cells in a battery can, in turn, allow for a reduction in the spacing between adjacent cells. Reducing the spacing between adjacent cells can reduce the battery's volume and mass (e.g., for a given capacity). The battery's mass can be reduced by decreasing the amount of material required to separate the cells. Reducing or minimizing the volume and / or mass of the battery pack can improve the performance of battery-powered vehicles by increasing or maximizing the vehicle's load-bearing capacity and / or driving range.

[0008] The plate may also include a plurality of holes. The holes may extend at least partially through the thickness of the plate. The holes may be arranged or positioned such that, when the plate is connected to the battery cell in use, each hole is configured to provide a fluid passage between the vent of the respective battery cell and the vent channel. This can further reduce the risk of thermal runaway propagation by reducing the direct exposure of other battery cells to vented gases from the failed battery cell (e.g., via the vent channel) during venting, thereby improving isolation between the failed battery cell and adjacent battery cells. The holes may be arranged or positioned such that, when the plate is connected to the battery cell in use, each hole may be substantially aligned with the respective battery cell to provide the fluid passage between the vent of that battery cell and the vent channel.

[0009] The cross-sectional area of ​​the exhaust channel can be larger than or include a cross-sectional area larger than that of each of the holes. This allows the fluid passage between the exhaust port of each cell and the external space to increase with the distance from the exhaust port, thereby allowing the gas to continue to expand to improve cooling during exhaust.

[0010] The cross-sectional area of ​​each of the holes and the venting channels may be equal to or greater than the cross-sectional area of ​​the vent of each cell connected to the board during use.

[0011] The venting channel may be formed in a surface of the plate opposite to the surface of the plate adjacent to the cell when the plate is connected to the cell in use. When the plate is connected to the cell in use, a first surface of the plate may be adjacent to the cell, and the venting channel may be formed in an opposing second surface of the plate. This can increase the separation or isolation between the cell and the venting channel during venting, thereby further reducing the risk of thermal runaway propagation.

[0012] The plate may also include a plurality of recesses formed in a surface of the plate adjacent to the cell when the plate is connected to the cell in use. The plate may provide sufficient thermal mass to absorb heat in the vicinity of a faulty cell (e.g., near the vent of a faulty cell). The recesses may provide an increased plate surface area in the vicinity of a faulty cell (e.g., near the vent of a faulty cell) to facilitate rapid localized heat transfer to the plate during venting, thereby rapidly reducing the temperature of the effluent locally. The recesses may also reduce the overall mass of the plate, which can improve the mechanical and electrical properties of the battery. The recesses may be arranged or positioned such that each recess is configured to be substantially aligned with the corresponding cell when the plate is connected to the cell in use. The recesses may have or include tapered, funnel-shaped, angled, or rounded openings. This allows material from the faulty cell to be guided into the recesses during venting without restricting the flow of the material.

[0013] Each of the holes may be located in a corresponding recess.

[0014] The cross-sectional area of ​​each recess can be substantially similar to the cross-sectional area of ​​the battery cell that it is substantially aligned with.

[0015] The plate may also include multiple one-way valves. The one-way valves may be arranged or positioned such that, when the plate is connected to the battery cell in use, each one-way valve is located in the fluid passage between the vent of the corresponding battery cell and the vent channel. The one-way valves allow material to flow outward from the faulty battery cell but prevent material from flowing towards adjacent battery cells, thereby further reducing the risk of thermal runaway propagation. The one-way valves may be arranged or positioned such that, when the plate is connected to the battery cell in use, each one-way valve is configured to be substantially aligned with the corresponding battery cell.

[0016] Each of the one-way valves may be disposed within a corresponding recess. Each one-way valve may be or include a sheet or plate of material disposed within the corresponding recess. Each sheet or plate of material may be configured to move within the recess to open or close the fluid passage between the exhaust port of the corresponding cell and the exhaust channel.

[0017] The plate may further include multiple expansion portions. These expansion portions may be arranged or positioned such that, when the plate is connected to the battery cell in use, each expansion portion is disposed in a fluid passage between the exhaust port of the corresponding battery cell and the exhaust channel. This provides an additional thermal barrier that reduces heat transfer from the gas vented from the faulty battery cell to adjacent battery cells. The expansion portions may be arranged or positioned such that, when the plate is connected to the battery cell in use, each expansion portion is configured to be substantially aligned with the corresponding battery cell.

[0018] Each of the expansion portions is disposed within a corresponding recess. Each expansion portion may be or includes a sheet or plate of material disposed within the corresponding recess.

[0019] Each of the expansion sections can form part of a corresponding one-way valve.

[0020] The plate may also include cooling channels configured to guide coolant flow through the plate.

[0021] The cooling passage and the exhaust passage may intersect each other. This provides an additional cooling mechanism to transfer heat away from the exhaust gas, thereby further reducing the risk of thermal runaway propagation.

[0022] The plate may include a first plate portion in which the venting channel is formed. The first plate portion may be configured to be electrically connected to the positive terminal or positive end of each of the first group of multiple cells. The plate may include a second plate portion. The second plate portion may be configured to be electrically connected to the negative terminal or negative end of each of the second group of multiple cells. The second plate portion may have or include a greater mass than the first plate portion. This can dissipate more heat from the negative terminal or negative end of each cell and also provide mechanical reinforcement to the negative terminal or negative end of each cell. This can reduce the likelihood of each cell breaking or failing at its negative terminal or negative end, thereby increasing the likelihood of the cell failing at its positive terminal or positive end. This allows for the location or placement of means for managing thermal runaway events primarily or entirely at or near the positive terminal or positive end of each cell. Centralized placement of means for managing thermal runaway events can reduce the volume and / or mass of the battery. This can be particularly advantageous for cylindrical cells; although a cylindrical cell can theoretically break or fail at any location, it is more likely to expel gas through the vent located at the positive terminal when it fails. Providing a venting channel that allows material from the failed cell to escape also reduces the likelihood of the vent at the positive terminal becoming blocked during use (a blockage that could otherwise cause the cell to break at different locations if the vent does not allow material to escape).

[0023] The first group of multiple cells and the second group of multiple cells may have or include the same number of cells.

[0024] The second plate portion may include one or more structures configured to hold each of the second group of multiple cells in a desired position relative to the second plate portion.

[0025] The second plate portion may be configured to provide structural support for each of the second group of multiple cells near the negative terminal. The second plate portion may include one or more structures configured to at least partially surround one end of each of the second group of multiple cells. This provides further mechanical reinforcement to the negative terminal of each cell.

[0026] According to a second aspect, a battery is provided. The battery may include a plurality of cells. Each cell may include a vent. The battery may also include a conductive plate electrically connected to each of the plurality of cells. The plate may be, or include, the conductive plate of the first aspect.

[0027] Each of the battery cells may be or includes a cylindrical battery cell. The plurality of battery cells may be arranged in a regular array.

[0028] The battery of the second aspect may include one or more features and / or advantages of the conductive plate of the first aspect, and vice versa.

[0029] According to a third aspect, a battery is provided. The battery may include a plurality of cylindrical cells. The battery may further include a first conductive plate electrically connected to the positive terminal of each cell. The battery may further include a second conductive plate electrically connected to the negative terminal of each cell. The second plate may have or include a greater mass than the first plate.

[0030] The second conductive plate can be directly coupled to the negative terminal of each cell. Direct coupling may include direct physical contact between the second plate and the negative terminal of each cell.

[0031] The second plate may include one or more structures configured to hold each cell in a desired position relative to the second plate.

[0032] The second plate may be configured to provide structural support for each of the battery cells near the negative terminal. The second plate may include one or more structures configured to at least partially surround one end of each of the battery cells.

[0033] The first plate may be or include the conductive plate of the first aspect.

[0034] According to a fourth aspect, a conductive plate is provided, configured to be electrically connected to each of a plurality of battery cells. The plate may include a first plate portion. The first plate portion may be configured to be electrically connected to the positive terminal of each battery cell in a first subset of the plurality of battery cells. The plate may further include a second plate portion. The second plate portion may be configured to be electrically connected to the negative terminal of each battery cell in a second subset of the plurality of battery cells. The second plate portion may include a greater mass than the first plate portion.

[0035] The second plate portion may include one or more structures configured to hold each cell in the second subset in a desired position relative to the second plate portion.

[0036] The second plate portion may be configured to provide structural support for each cell in the second subset near the negative terminal of the cell. The second plate portion may include one or more structures configured to at least partially surround one end of each cell in the second subset.

[0037] The fourth aspect of the plate may include one or more features and / or advantages of the conductive plate of the first aspect, the battery of the second or third aspect, or vice versa.

[0038] According to a fifth aspect, an electric vehicle including a battery is provided. The battery may be or include the battery of the second or third aspect. The battery may include a conductive plate of the first or fourth aspect.

[0039] The electric vehicle may be a motor vehicle, such as a car, truck, van, or freight vehicle.

[0040] Features described in the context of different aspects and embodiments of the invention may be used together and / or interchanged whenever possible. Similarly, features described in the context of a single embodiment for the sake of brevity may also be provided individually or in any suitable sub-combination. Attached Figure Description

[0041] Embodiments of the present invention will now be described by way of example only with reference to the following accompanying drawings, in which: Figure 1 An embodiment of the battery pack according to the present invention is shown; Figure 2A and Figure 2B It shows Figure 1 The modules or batteries of the battery pack shown; Figure 3 It shows Figure 2A and Figure 2B The battery cells of the module shown; Figure 4A and Figure 4B The top and bottom surfaces of a first portion of a conductive plate are shown, which are connected to Figure 2A and Figure 2B The positive terminal of the battery cell in the module shown; Figure 5 It shows crossing Figure 4A and Figure 4B The cross-sectional view of the first plate shown includes a one-way valve mechanism; Figure 6A and Figure 6B Another embodiment of a first portion of a conductive plate is shown, the first portion being configured to connect to the positive terminal of a cell in a module of a battery pack; and Figure 7 It shows Figure 2A and Figure 2B The conductive plate of the module shown includes a first plate portion and a second plate portion.

[0042] The same reference numerals in different figures may represent the same elements. Detailed Implementation

[0043] Figure 1One embodiment of a battery pack 100 is shown. The battery pack 100 includes a plurality of batteries or modules 105. In the illustrated embodiment, the battery pack 100 includes one hundred and ten modules 105, wherein each of the eleven battery strings 108 comprises ten modules 105. Alternatively, the battery pack 100 may include any suitable number of batteries or modules 105. Each battery string 108 is oriented to extend along the length of the battery pack 100 (generally from left to right or from right to left), and the modules 105 in each battery string 108 are connected in series along the length of the battery string 108, although this is not necessary. In the illustrated embodiment, each module 105 includes a plurality of cylindrical cells 140 arranged in a regular, ordered array, each cell 140 having a diameter of 21 mm and an axial length of 70 mm. However, it should be understood that, alternatively, each module 105 may include a plurality of cells having any suitable size, shape, or construction and arranged in any suitable manner.

[0044] Each module 105 includes a pair of conductive plates (shown in more detail in FIG. 2), with a plurality of battery cells 140 located between the pair of conductive plates. The battery cells 140 are electrically connected in parallel between the conductive plates. The conductive plates serve as buses and may be referred to as such throughout this disclosure. Each of the conductive plates includes a substantially monolithic structure formed of a conductive material, such as a metal or metal alloy, such as an aluminum alloy or copper. The conductive plates of each module 105 collectively provide a respective top surface 120 and bottom surface 130 of the battery pack 100. The top surface 120 and bottom surface 130 each provide an adhesive surface for securing material sheets or material panels (not shown). The respective material panels may be secured to the top surface 120 and bottom surface 130 by any suitable means, such as using adhesives, one or more fasteners, welding, etc. The battery pack 100, together with the panels, effectively forms a structural element having a layered or sandwich structure, wherein the battery pack 100 itself serves as the core material of the layered structure.

[0045] Each battery string 108, comprised of modules 105, includes terminals 110 to allow external electrical connection to the battery pack 100, such as connecting the battery pack 100 to a load. In the illustrated embodiment, each battery string 108 includes a terminal 110 at each end. This allows the battery pack 100 to be divided into individual low-voltage battery strings 108 for safer user operation. This also allows the battery pack 100 to be configured to connect the battery strings 108 in series or parallel externally. This also allows the overall disconnect device to be positioned to internally isolate the battery pack 100 (i.e., there is no voltage on the terminals 110 of the battery pack 100). Alternatively, the battery strings 108 can be connected to each other within the battery pack 100, leaving only two terminals on the battery pack 100, such as the positive and negative terminals; or four terminals 110 can be left on the battery pack 100, such as the positive terminal, the negative terminal, and two terminals within the battery pack 100, to allow for the installation of a main service disconnect device (which may be preferred for high-voltage applications, such as applications above 50V).

[0046] Figure 2A and Figure 2B The module 105 of the battery pack 100 is shown in more detail in an exploded view. In the illustrated embodiment, in addition to the modules 105 at both ends of the battery string 108, each conductive plate or busbar of the battery cells 140 located therebetween in module 105 includes a first plate portion 150 and a second plate portion 155. The first plate portion 150 is arranged to be connected to the positive terminal of each battery cell 140. Throughout this disclosure, the first plate portion 150 may also be referred to as a positive plate portion. The second plate portion 155 is arranged to be electrically connected to the negative terminal of each battery cell 140. Throughout this disclosure, the second plate portion 155 may also be referred to as a negative plate portion. By providing conductive plates or busbars each having a first plate portion 150 and a second plate portion 155, the modules 105 can be connected in series along the length of the battery string 108 by alternating the longitudinal orientation of the cells 140 in adjacent modules 105 and using busbars to connect the positive terminal of the cell 140 of one module 105 to the negative terminal of the cell 140 of the adjacent module 105 and vice versa. It should be understood that the conductive plates at both ends of the battery string 108 may include only the features of the first plate portion 150 or only the features of the second plate portion 155, depending on whether the plates are connected to the positive or negative terminal of the cell 140. It should also be understood that the battery pack 100 may include a single module 105, in which case the module 105 may include a pair of conductive plates connected to the positive and negative terminals of the cell 140, respectively, one plate having only the features of the first plate portion 150 and the other plate having only the features of the second plate portion 155. Each module 105 includes the same number of cells 140 to prevent some modules 105 from running out of power earlier than others, thus compromising the available capacity of the battery pack 100, although this is not necessary.

[0047] In the illustrated embodiment, the first plate portion 150 of the busbar is electrically connected to the positive terminal of the cell 140 via a conductive sheet 160, which includes a plurality of fuses 160a formed therein. The conductive sheet 160 may also be referred to as a fusible busbar. The conductive sheet 160 is formed of copper, but alternatively, it may also be formed of aluminum, nickel-plated aluminum, or any suitable conductive material. Each fuse 160a is physically connected to the positive terminal of the corresponding cell 140. Figure 2B The enlarged view shows fuse 160a, taken from [source missing]. Figure 2A The square portion is marked with a dashed line. In the illustrated embodiment, fuse 160a includes a central portion 160b for connection to the positive terminal of the battery cell 140. The central portion 160b is held in place and fixed to the conductive sheet 160 via a fuse arm 160c. The fuse arm 160 has a generally helical shape; however, alternatively, fuse arms with other shapes or configurations (e.g., straight fuse arms, curved fuse arms, etc.) may be used.

[0048] The structure of fuse 160a allows for vertical movement (e.g., to accommodate vertical tolerances) while limiting lateral movement of the central portion 160b. Fuse 160a also has a cross-section that can melt in the event of excessive current from a single cell 140, thereby electrically disconnecting cell 140 from module 105. In the event of thermal runaway due to a failure of cell 140, fuse 160a can be melted by hot gases escaping from that cell, thereby electrically disconnecting cell 140 from module 105. The conductive tab 160 or fuse 160a can be connected to the positive terminal of cell 140 in any suitable manner, such as by welding (e.g., ultrasonic welding, laser welding, resistance welding), using conductive adhesive, etc. Alternatively, module 105 may not include such a conductive tab or fusible bus 160. Alternatively, the first plate portion 150 of the bus may be directly electrically connected to the positive terminal of cell 140.

[0049] The cells 140 in each module 105 are arranged in a regular array. In the illustrated embodiment, the cells 140 are arranged in a hexagonal close-packed manner; however, any other regular stacking structure may be used alternatively. Each bus or conductive plate includes a shaped periphery that substantially mimics the periphery of the array of cells 140 in module 105. This maximizes the surface area of ​​each plate for electrical and / or thermal conduction while suppressing or preventing arcing between plates of adjacent modules 105. For example, the shaped periphery of each plate may provide gaps or spaces to provide electrical and thermal isolation between buses of adjacent modules 105. In the illustrated embodiment, each module 105 includes seven cells 140; however, each module 105 may include any suitable number of cells 140.

[0050] The cells 140 within module 150 are spaced apart to provide thermal and electrical isolation between them in the array. A filler material is disposed in the spaces between the cells 140. When the filler material is present in the spaces between the cells 140, the cells 140 can reinforce each other under axial loads without direct contact, which can improve the axial strength of module 105 by increasing the ability of the cells 140 to resist buckling or bulging deformation under axial loads. The filler material is electrically insulating to ensure the safety of module 105 and battery pack 100 in the event of a short-circuit fault, although this is not essential (e.g., depending on whether the cells 140 have an insulating jacket or surface). The filler material is also thermally insulating to suppress the propagation of thermal runaway caused by the failure of a cell 140 (i.e., thermal runaway caused by the failure of one cell 140 triggering thermal runaway in another cell 140 in module 105), although this is not essential. In the illustrated embodiment, the filler material is an adhesive (e.g., a structural adhesive) that holds the cells 140 together, which can improve the shear strength of the module 105, although this is not necessary. It should be understood that the module 105 may not include filler material disposed in the spaces between the spaced-apart cells 140.

[0051] Module 105 includes a jig 165. The jig 165 is positioned above the end of each cylindrical cell 140 adjacent to its positive terminal, such that the jig 165 holds or secures each cell 140 in a desired position or location within module 105. The jig 165 ensures that the cells 140 are correctly positioned to maintain a desired gap between them. This allows the cells 140 to be correctly positioned within module 105, for example, when any filler material is supplied (and, for example, when any adhesive filler has cured). The jig 165 also provides a physical barrier to prevent debris or foreign objects from falling into the space between the cells 140.

[0052] Figure 3A typical cylindrical battery cell 140 is shown. The battery cell 140 includes a cylindrical body 142 constituting the negative terminal of the battery cell 140. The battery cell 140 also includes a positive terminal 144 located at one end of the battery cell 140, which constitutes an end cap of the cylindrical battery cell 140. The positive terminal 144 is electrically insulated from the negative cylindrical body 142 by an insulating material (e.g., a layer of plastic material) located between the cylindrical body 142 and the positive terminal 144. In the illustrated embodiment, a jig 165 is positioned above the end of the battery cell 140 adjacent to the positive terminal 144 to provide further electrical insulation between the negative terminal 142 and the positive terminal 144 of each battery cell. The jig 165 is made of plastic material; however, any suitable electrical insulating material may be used alternatively. It should be understood that module 105 may not include the jig. The battery cell 140 also includes a vent 146. The vent 146 surrounds and is located below the positive terminal 144. The vent 146 is configured to allow gas to be released from the cell 140 in the event of thermal runaway.

[0053] The first plate portion 150 and the second plate portion 155 of the bus are each configured to provide cooling and / or manage thermal runaway events (such as events that cause cell 140 to fail).

[0054] Figure 4A and Figure 4B The first plate portion 150 of the bus is shown. The bus shown is configured for the end of the battery string 108, and therefore only includes the first plate portion 150. However, it should be understood that the same features can be applied to buses that include both the first plate portion 150 and the second plate portion 155.

[0055] The first plate portion 150 includes a plurality of exhaust channels 170. In the illustrated embodiment, the exhaust channels 170 are formed in the top or outer surface 120a of the first plate portion 150 (the top surface 120a forms part of the top surface 120 of the module 105 or battery pack 100). The top surface 120a is opposite to the bottom or inner surface 120b of the first plate portion 150 that faces and is electrically connected to the cell 140 thereto (e.g., via a fusible bus or conductive sheet 160). The bottom surface 120b provides a larger surface area for electrical and thermal conduction from the cell through the first plate portion 150. The exhaust channels 170 are in fluid communication with the exhaust port 146 of each cell 140. When a cell 140 fails during a thermal runaway event, the failed cell 140 exhausts a volume of high-temperature gas (e.g., hydrocarbon gas). Therefore, when cell 140 fails during a thermal runaway event, the high-temperature gas emitted from the failed cell 140 can flow along exhaust channel 170 and be discharged to the external space from module 105 or battery pack 100 via an outlet. For example, exhaust channel 170 may lead to an exhaust port in the casing of battery pack 100, such as an exhaust port located on the side of battery pack 100. In the illustrated embodiment, when the material plate is fixed to the top surface 120a (as described above regarding...), Figure 1 The exhaust passage 170 forms a substantially closed channel. However, it should be understood that, alternatively, the exhaust passage 170 may also be formed in the lower surface 120b of the first plate portion 150, or formed inside the first plate portion 150 (e.g., between the top surface 120a and the bottom surface 120b). The first plate portion 150 may include any suitable number of exhaust passages 170 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc.). The exhaust passages 170 in the first plate portion 150 are arranged such that, in a battery pack 100 including a plurality of modules 105, the exhaust passages 170 formed in the busbars of adjacent modules 105 are configured to align with each other to provide a continuous fluid passage across the plurality of modules 105 of the battery pack 100, allowing hot gases from the faulty cell 140 to flow through the busbars. Figure 1 The exhaust is directed to an external space outside the battery pack 100. However, this is not necessary. For example, the exhaust passage 170 may have a volume sufficient to accommodate material discharged from the faulty cell 140 without having to discharge the discharged material from the back of the battery 100. Alternatively, the exhaust passages 170 formed in the busbars of adjacent modules 105 may each provide a separate fluid path to a separate vent in the battery pack 100, and it may be possible to allow material to be discharged from the battery pack 100 without coordinating the exhaust passages 170 of the busbars of adjacent modules 105 with each other.

[0056] The venting channel 170 on the top surface 120a is in fluid communication with the vent 146 of the cell 140 via a plurality of holes 172 formed in the bottom surface 120b. The extent to which the holes 172 extend through the thickness of the first plate portion 150 may depend on the location of the venting channel 170 (e.g., whether the venting channel 170 is formed in the top surface 120a, the bottom surface 120b, or between the top surface 120a and the bottom surface 120b of the first plate portion 150). It should be understood that if the venting channel 170 is formed in the bottom surface 120b, the first plate portion 150 may not include holes. The holes 172 are arranged to be substantially aligned with the vent 46 of the corresponding cell 140 to provide a fluid passage between the vent 146 of the cell 140 and the venting channel 170. In the illustrated embodiment, each hole 172 has a substantially circular cross-section, however this is not necessary, and the holes 172 may have any suitable shape or configuration.

[0057] The cross-sectional area of ​​each hole 172 is equal to or greater than the cross-sectional area of ​​the vent 146 of the cell 140. The cross-sectional area of ​​the vent passage 170 is greater than the cross-sectional area of ​​the hole 172. The increased cross-sectional area of ​​the fluid passage from the vent 146 through the hole 172 into the vent passage 170 allows hot gas vented from the faulty cell 140 to expand (and thus cool) as it exits the module 105, although this is not necessary.

[0058] The first plate portion 150 also includes a plurality of recesses 175. The recesses 175 are formed in the bottom surface 120b of the first plate portion 120 facing or adjacent to the cell 140. The recesses 175 are generally circular, but this is not necessary, and the recesses 175 can have any suitable shape. Each recess 175 is generally aligned with the corresponding cell 140 such that each recess 175 is generally located on opposite sides of one end of the cell 140, but this is not necessary.

[0059] When cell 140 fails due to thermal runaway, the hot gas discharged from vent 146 of cell 140 is directed and enters recess 175. Recess 175 provides a larger contact surface area (e.g., compared to a flat surface) of the first plate portion 150 for the hot gas discharged from cell 140, thereby enabling rapid local heat transfer from the gas after discharge and thus rapid cooling of the gas. Providing recess 175 in the first plate portion 150 also increases the cross-sectional area of ​​the first plate portion 175 while reducing or minimizing its mass. The cross-sectional area of ​​the first plate portion 150 determines its electrical and thermal conductivity. A thicker busbar can reduce electrical and heat losses and allow the busbar to be used to cool the cell (e.g., by conducting heat to cooler surfaces, such as the outer surface of module 105 or battery pack 100). The greater the mass of material present in the busbar, the more heat energy the busbar can absorb for a given temperature rise (the busbar provides a larger endothermic heat mass). During a thermal runaway or failure of cell 140, ensuring that adjacent cells 140 are not exposed to temperatures that could induce thermal runaway (which could cause the cell failure to propagate throughout module 105) is crucial. Therefore, providing a bus in the form of a first plate portion 150 can provide sufficient heat-absorbing mass near the failed cell 140, thereby maintaining a locally low temperature. Providing a recess 175 in the first plate portion 150 can simultaneously provide a larger surface area, allowing for rapid local heat transfer from the gas to the first plate portion 150, thereby rapidly reducing the temperature of the exhaust gas locally. In the illustrated embodiment, an aperture 172 is provided in the recess 175; however, this is not necessary. It should also be understood that the first plate portion 150 may not include a recess.

[0060] The first plate portion 150 also includes a connection hole 178. The connection hole 178 is configured to receive bolts or other fasteners (not shown) to secure the first plate portion 150 to the conductive sheet 160 and the fixture 165. Alternatively, these components may be secured to each other using other means, such as adhesives or thermal riveting. This allows the connection hole 178 to receive fasteners to secure the first plate portion 150 to a second plate portion 155 located at the opposite end of the cell 140 (e.g., the fastener may extend substantially through the entire thickness of the module 105).

[0061] The terminal 110 of the first plate portion 150 includes a threaded hole 112. The threaded hole 112 allows for an isolated electrical connection between two battery strings 108, connection to a main service disconnect device, or connection to a load external to the battery pack 100. The terminal 110 does not necessarily have to include a threaded hole.

[0062] The first plate portion 150 also includes a cooling channel 180. The cooling channel 180 is configured to guide coolant flow through the first plate portion 150 to provide active cooling to the module 105. In the illustrated embodiment, the cooling channel 180 is disposed in the top surface 120a of the first plate portion 150, but this is not necessary. The cooling channel 180 is arranged or positioned such that, in a battery pack 100 including multiple modules 105, the cooling channels 180 formed in the busbars of adjacent modules 105 are configured to align with each other to provide a continuous passage across the multiple modules 105 of the battery pack 100, allowing coolant to flow through the battery pack 100 as needed. Figure 1 As shown, the flow passes through multiple modules 105 and flows through the entire battery pack 100.

[0063] Cooling channel 180 intersects with exhaust channel 170. The depth of cooling channel 180 is less than the depth of exhaust channel 170. This allows a pipe or tube (not shown) containing coolant to be placed in cooling channel 180 without obstructing exhaust channel 170. Exhaust channel 170 can effectively pass under cooling channel 180 to allow exhaust gases to be vented to the outside space. The intersection of cooling channel 180 and exhaust channel 170 also allows the coolant to provide additional direct cooling to exhaust gases from any failed cell 140. However, this is not necessary, and cooling channel 180 can be spatially separated from exhaust channel 170. It should also be understood that the first plate portion 150 may not have a cooling channel.

[0064] Figure 5 A cross-sectional view is shown of the first plate portion 150 connected in situ to the cell 140. A one-way valve mechanism 185 is disposed in the recess 175. In the illustrated embodiment, the one-way valve 185 includes a sheet or plate of material 185a housed in the recess 175. The recess 175 includes an opening 175a formed in the bottom surface 120b of the first plate portion 150, and a lip, step, or shoulder 175b recessed inward from the opening 175a. The lip 175b increases the width of the recess 175 relative to the width of the opening 175a. The lip 175b provides a surface for the plate 185a to abut against, the width or diameter of which is greater than the width or diameter of the opening 175a, but does not extend across the entire width or diameter of the recess 175 outside the lip 175b (thus leaving space for exhaust gas to reach the orifice 172 and the exhaust passage 170).

[0065] When cell 140 fails due to thermal runaway, the hot gas discharged from the exhaust port 146 of cell 140 is directed towards and enters the recess 175. The hot gas flow F from the failed cell 140 forces plate 185a within the recess 175 to move "upward," or away from opening 175a and against the innermost surface of the recess 175. Plate 185a has a width or diameter such that when pushed upward by the airflow F, plate 185a does not obstruct the hole 172 formed in the recess 175, thus allowing hot gas to reach the exhaust passage 170. However, if hot gas flows through the exhaust passage 170 and enters the hole 172 aligned with an adjacent cell 140, the airflow F forces plate 185a to move "downward," or towards the opening 175a of the adjacent recess 175. Therefore, plate 185a effectively closes opening 175a and protects adjacent cells 140 from exposure to hot gases emanating from the faulty cell 140. Plate 185a may be made of or comprise an intumescent material. The intumescent material absorbs heat from the hot gas, thereby expanding and carbonizing. The activated intumescent material then provides a thermal barrier that reduces heat transfer to adjacent cells 140. The expansion of the intumescent material of plate 185a may not inhibit the outward flow of airflow F from the faulty cell 140, but may help close opening 175a aligned with adjacent cells 140 to protect these adjacent cells from the airflow F. Alternatively, plate 185a may comprise any suitable material, such as aluminum or copper for absorbing heat from the hot gas flow F. However, it should be understood that, alternatively, any suitable one-way valve mechanism may be provided in the fluid passage between each cell 140 and the exhaust passage 170 to provide similar functionality. Alternatively, the first plate portion 150 may not include a one-way valve mechanism.

[0066] Alternatively, the first plate portion 150 may include an expandable material that does not form part of the one-way valve mechanism. For example, a portion of the expandable material may be provided at a fixed position within the recess 175, or at any suitable location on the fluid path between the exhaust port of the cell 140 and the exhaust passage 170, or it may be provided within the exhaust passage 170 itself.

[0067] Figure 6A and Figure 6B Another embodiment of the first plate portion 250 is shown. The first plate portion 250 is related to... Figures 1 to 5 The first plate portion 150 described is substantially similar, wherein the same reference numerals denote the same elements.

[0068] The hole 272 is generally arc-shaped and is disposed along the circumference or periphery of the recess 275. The recess 275 includes a first lip or shoulder 275b for positioning a plate 285a. The plate 285a is positioned against the first lip 275b to prevent hot gas flow F from another faulty cell 140 (not shown) from reaching the cell 140 located below the plate 285a. The recess 275 also includes a second lip or shoulder 275c that increases the width or diameter of the recess 275 so that, in the event of a fault in the cell 140 (not shown) located below the plate 285a, the exhaust gas flow F can flow through the plate 285a and reach the hole 272. In the illustrated embodiment, the opening 275a of the recess 275 is tapered. This can be used to guide the hot gas flow F from the faulty cell 140 into the recess 275 without restricting the airflow F (e.g., avoiding the stepped, sharp vertical edges that would exist in the recess 275 without the tapered opening 275a). However, this is not necessary. The first plate portion 250 also includes a voltage sampling position 290, but this is not necessary either.

[0069] Returning to Figure 2 (and in Figure 7 (Shown separately) Each conductive plate includes a first plate portion 150 electrically connected (or connectable) to the positive terminal of the cell 140. Each conductive plate also includes a second plate portion 155 electrically connected (or connectable) to the negative terminal of each cell 140. The second plate portion 155 is also directly coupled to the negative terminal of each cell 140 to provide direct electrical and thermal conduction between the second plate portion 155 and the negative terminal of each cell 140.

[0070] Back Figure 3 The internal chemical materials of a typical cylindrical battery cell 140 are arranged such that the thermal conductivity in the axial or longitudinal direction is significantly greater than that in the radial direction (e.g., up to 100 times greater). Furthermore, an air gap is typically provided below the positive terminal 144 at one end of the battery cell 140 to provide thermal insulation. Therefore, the opposite axial end of the cylindrical battery cell 140 is typically the location from which the greatest amount of heat can be removed most quickly.

[0071] The second plate portion 155 of the plate or busbar has a greater mass than the first plate portion 150. Having a larger mass of material near the axial end of the negative terminal of the cell 140 allows more heat to be removed from the cell 140 at that location compared to other parts of the cell 140. This heat removal can also be achieved more quickly by utilizing the increased thermal conductivity of the cell 140 in the axial direction. Directly coupling the second plate portion 155 to the cell 140 further improves the cooling of the cell 140.

[0072] In the illustrated embodiment, as described above with respect to FIG2, each bus or conductive plate includes a shaped periphery that substantially mimics the periphery of the array of cells 140 in module 105. Therefore, the surface area of ​​the second plate portion 155 is substantially fixed. By maintaining the full thickness of the second plate portion 155 on a larger portion of its surface, rather than removing material (e.g., to provide venting and / or cooling channels 170), the mass of the second plate portion 155 is increased relative to the mass of the first plate portion 150. However, it should be understood that the second plate portion 155 may also include cooling channels (e.g., cooling channels 180 similar to those of the first plate portion 155) and still have a greater mass than the first plate portion 150.

[0073] The greater mass of the second plate portion 155 also provides mechanical reinforcement to the cell 140 adjacent to the axial end. This reduces the likelihood of the cell 140 breaking or failing at the negative terminal. Consequently, this increases the likelihood that any failure of the cell 140 will occur at the positive terminal, which is adjacent to the first plate portion 150, which includes features designed to manage the hot gases emitted by the cell 140 in the event of thermal runaway. Therefore, the first plate portion 150 and the second plate portion 155 located at opposite ends or sides of each module 105 can work together to both reduce the risk of thermal runaway and manage cell failure events, thereby preventing the propagation of thermal runaway throughout the module 105.

[0074] The second plate portion 155 also includes a plurality of structures 195 for holding the cell 140 relative to the second plate portion 155 in a desired position. In the illustrated embodiment, each structure 195 includes a raised region that at least partially surrounds the outer surface (e.g., the outer cylindrical surface of the cell 140) of one or more cells 140. The raised region 195 is positioned in the space provided between the cells 140 in the array. The raised region 195 may also provide further mechanical reinforcement to the cell 140 adjacent to this axial end of the cell 140. In the illustrated embodiment, each raised region 195 has a generally triangular shape and has recessed or curved sides for closer engagement with the outer surface of the cell 140. However, the structure 195 may have any suitable shape or construction, such as a generally annular or arcuate shape that at least partially surrounds one end of the cell 140.

[0075] Other variations and modifications will become apparent to those skilled in the art upon reading this disclosure. Such variations and modifications may involve equivalent features and other features known in the field of batteries, which may replace or be used in addition to the features already described herein.

[0076] Although the appended claims address specific combinations of features, it should be understood that the scope of the invention also includes any novel feature or combination of novel features or any generalization thereof explicitly or implicitly disclosed herein, whether or not it relates to the same invention as currently claimed in any of the claims, and whether or not it alleviates any or all of the same technical problems as the present invention.

[0077] Features described in the context of different implementations may also be provided in combination in a single implementation. Conversely, various features described in the context of a single implementation for the sake of brevity may also be provided individually or in any suitable sub-combination. The applicant hereby declares that new claims may be drafted for these features and / or combinations thereof during the examination of this application or any subsequent application derived therefrom.

[0078] For completeness, it should also be noted that the term "comprising" does not exclude other elements or steps, the term "a" does not exclude multiple, and no reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A conductive plate configured to be electrically connected to each of a first group of multiple battery cells, the plate comprising: An exhaust passage is formed in the plate; The exhaust passage is arranged such that, when the plate is connected to the battery cell in use, the exhaust passage is configured to be in fluid communication with the exhaust port of each battery cell to provide a fluid passage between the exhaust port of each battery cell and the space outside the battery cell.

2. The plate according to claim 1, wherein, The plate also includes: Multiple holes, the multiple holes extending at least partially through the thickness of the plate; The holes are arranged or positioned such that, when the plate is connected to the cell in use, each hole is configured to provide a fluid passage between the vent and the vent channel of the corresponding cell.

3. The plate according to claim 2, wherein, The cross-sectional area of ​​the exhaust channel is larger than the cross-sectional area of ​​each of the holes.

4. The plate according to claim 2 or claim 3, wherein, The cross-sectional area of ​​each of the holes and the venting channels is equal to or greater than the cross-sectional area of ​​the vent of each cell connected to the board in use.

5. The plate according to any one of claims 2 to 4, wherein: When the plate is connected to the battery cell in use, a first surface of the plate is adjacent to the battery cell, and the venting channel is formed in the opposite second surface of the plate.

6. The plate according to any one of the preceding claims, wherein, The plate also includes: Multiple recesses are formed in the surface of the plate adjacent to the cell when the plate is connected to the cell in use; and optionally... The recesses are arranged such that when the plate is connected to the battery cell in use, each recess is configured to be substantially aligned with the corresponding battery cell.

7. The plate according to claim 6, which refers to any one of claims 2 to 5, wherein, Each of the holes is located in a corresponding recess.

8. The plate according to claim 6 or claim 7, wherein, The cross-sectional area of ​​each recess is roughly similar to the cross-sectional area of ​​the battery cell it is basically aligned with.

9. The plate according to any one of the preceding claims, wherein, The plate also includes: Multiple check valves; The one-way valve is arranged such that when the plate is connected to the battery cell in use, each one-way valve is located in the fluid passage between the exhaust port and the exhaust channel of the corresponding battery cell.

10. The plate according to claim 9, which refers to any one of claims 6 to 8, wherein, Each of the one-way valves is disposed within a corresponding recess.

11. The plate according to any one of the preceding claims, wherein, The plate also includes: Multiple expansion sections; and optionally The expansion portion is arranged such that, when the plate is connected to the battery cell in use, each expansion portion is disposed in the fluid passage between the exhaust port and the exhaust channel of the corresponding battery cell.

12. The plate according to claim 11, which refers to any one of claims 6 to 8, wherein, Each of the expansion portions is disposed within a corresponding recess.

13. The plate according to claim 11 or claim 12 of claim 9 or claim 10, wherein, Each of the expansion sections forms part of a corresponding one-way valve.

14. The plate according to any of the preceding claims, wherein, The plate also includes: A cooling channel configured to guide coolant flow through the plate.

15. The plate according to claim 14, wherein, The cooling passage and the exhaust passage intersect each other.

16. The plate according to any one of the preceding claims, wherein, The plate includes: A first plate portion, wherein the exhaust passage is formed in the first plate portion; The first plate is configured to be electrically connected to the positive terminal of each of the first group of multiple battery cells; and Second section; The second plate is configured to be connected to the negative terminal of each of the second group of multiple battery cells; and The second plate portion has a greater mass than the first plate portion.

17. The plate according to claim 16, wherein, The second plate includes one or more structures configured to hold each of the second group of multiple cells in a desired position relative to the second plate.

18. The plate according to claim 16 or claim 17, wherein, The second plate is configured to provide structural support for each of the second group of multiple cells near the second terminal of the second group of multiple cells, and optionally, the second plate includes one or more structures configured to at least partially surround one end of each of the second group of multiple cells.

19. A battery comprising: Multiple battery cells, each including a vent; and The plate according to any of the preceding claims is electrically connected to the battery cell.

20. A battery, comprising: Multiple cylindrical battery cells; A first conductive plate is electrically connected to the positive terminal of each battery cell; as well as The second conductive plate is electrically connected to the negative terminal of each cell; The second plate has a greater mass than the first plate.

21. The battery according to claim 20, wherein, The second conductive plate is directly coupled to the negative terminal of each cell.

22. The battery according to claim 20 or claim 21, wherein, The second board: i) including one or more structures configured to hold each cell in a desired position relative to the second plate; and / or ii) is configured to provide structural support for each of the battery cells near the negative terminal of the battery cell, and optionally, wherein the second plate includes one or more structures configured to at least partially surround one end of each of the battery cells.

23. The battery according to any one of claims 20 to 22, wherein, The first conductive plate comprises the conductive plate according to any one of claims 1 to 18.

24. A conductive plate configured to be electrically connected to each of a plurality of battery cells, comprising: A first plate portion is configured to be electrically connected to the positive terminal of each of the plurality of battery cells in a first subset; as well as The second plate is configured to be electrically connected to the negative terminal of each cell in a second subset of the plurality of cells; The second plate portion has a greater mass than the first plate portion.

25. The plate according to claim 24, wherein, Second plate section: i) Includes one or more structures configured to hold each cell in the second subset in a desired position relative to the second plate portion; and / or ii) configured to provide structural support for each cell in the second subset near the negative terminal of the cell, and optionally, wherein the second plate portion includes one or more structures configured to at least partially surround one end of each cell in the second subset.

Images