SYSTEMS FOR SUPPRESSING THERMAL RUNAWAY IN BATTERY CELLS

Abstract

A system configured to suppress thermal runaway in a battery cell. The system comprises a battery cell stack with: C cathode electrodes, each comprising a cathode current collector, a cathode active layer arranged on the cathode current collector, and an outer connector extending from the cathode current collector; A anode electrodes, each comprising an anode current collector, an anode active layer arranged on the anode current collector, and an outer connector extending from the anode current collector; and S separators. C, A, and S are integers greater than one. A chamber is configured to store a suppressant configured to suppress thermal runaway.A valve is configured to open in response to a state of thermal runaway at the battery cell stack in order to release the suppressant from the chamber into the battery cell stack.

Description

INTRODUCTION

[0001] The information contained in this section serves to present the general context of the disclosure. The work of the inventors mentioned herein, insofar as it is described in this section, as well as aspects of the description that may not otherwise be part of the prior art at the time of filing, are neither expressly nor implicitly recognized as prior art with respect to the present disclosure.

[0002] The present disclosure relates to a system for suppressing thermal runaway in battery cells.

[0003] Electric vehicles (EVs), such as battery electric vehicles (BEVs) and hybrid vehicles and / or fuel cell vehicles, comprise one or more electric machines (such as one or more motors) and a battery system with one or more battery cells, modules, and / or packs. A power control system is used to control the charging and / or discharging of the battery system during charging and / or driving. SUMMARY

[0004] The present disclosure includes, in various features, a system configured to suppress thermal runaway in a battery cell. The system includes a battery cell stack having: C cathode electrodes, each comprising a cathode current collector, a cathode active layer disposed on the cathode current collector, and an external connector extending from the cathode current collector; A anode electrodes, each comprising an anode current collector, an anode active layer disposed on the anode current collector, and an external connector extending from the anode current collector; and S separators. C, A, and S are integers greater than one. A chamber is configured to store therein a suppressant configured to suppress thermal runaway.A valve is configured to open in response to a state of thermal runaway at the battery cell stack in order to release the suppressant from the chamber into the battery cell stack.

[0005] In other respects, the battery cell is a prismatic battery cell.

[0006] In other respects, the battery cell is a cylindrical battery cell.

[0007] In other features, the battery cell stack and the chamber are housed in a common casing.

[0008] In other features, the chamber is spaced apart from a housing containing the battery cell stack and connected to the housing by a conductor.

[0009] In further features, the present disclosure comprises a plate within a housing in which the battery cell stack is received, wherein the plate separates the chamber from the battery cell stack, and wherein the valve is contained in the plate.

[0010] In other features, the valve includes a tear seam running along the plate.

[0011] In other features, the chamber is configured so that the suppressant is stored as a liquid.

[0012] In other features, the suppressant is configured to evaporate after being released from the chamber to the battery cell stack.

[0013] In other respects, the suppressant contains a fluorinated ketone.

[0014] In further features, the chamber is defined by a vessel configured to be inserted into a housing containing the battery cell stack.

[0015] The present disclosure comprises, in various features, a system configured to suppress thermal runaway in a battery cell. The system comprises: a housing; a battery cell stack within the housing, including: C cathode electrodes, each comprising a cathode current collector, a cathode active layer arranged on the cathode current collector, and an outer connector extending from the cathode current collector; A anode electrodes, each comprising an anode current collector, an anode active layer arranged on the anode current collector, and an outer connector extending from the anode current collector; and S separators, wherein C, A, and S are integers greater than one. Within the housing, a chamber is defined that is configured to store a suppression agent configured to suppress thermal runaway.A valve is configured to open in response to a state of thermal runaway at the battery cell stack in order to release the suppressant from the chamber into the battery cell stack.

[0016] Other features include a partition within the housing that partially defines the chamber and contains the valve.

[0017] In other features, the partition is attached to an inner wall of the housing.

[0018] In other features, the valve has a tear seam.

[0019] In other respects, the chamber is partially defined by the housing.

[0020] In other features, the chamber is defined by a vessel configured to be inserted into the housing.

[0021] The present disclosure further comprises, in various features, a system configured to suppress thermal runaway in a battery cell. The system comprises a battery cell stack with: C cathode electrodes, each comprising a cathode current collector, a cathode active layer arranged on the cathode current collector, and an outer connector extending from the cathode current collector; A anode electrodes, each comprising an anode current collector, an anode active layer arranged on the anode current collector, and an outer connector extending from the anode current collector; and S separators, wherein C, A, and S are integers greater than one. A chamber is connected to the battery cell stack via a conductor, the chamber being configured to store a suppressant configured to suppress thermal runaway.A valve is configured to open in response to a state of thermal runaway at the battery cell stack, in order to release the suppressant through the line from the chamber into the battery cell stack.

[0022] In further features, the battery cell stack is a first battery cell stack, the conduit is a first conduit, and the valve is a first valve. The chamber is connected to a second battery cell stack via a second conduit, and a second valve is configured to open in response to a thermal runaway condition at the second battery cell stack to release the suppressant from the chamber into the second battery cell stack via the second conduit.

[0023] In further features, the battery cell stack is contained in a prismatic battery cell or a cylindrical battery cell.

[0024] Further areas of applicability of the present disclosure will become apparent from the detailed description, claims, and drawings. The detailed description and specific examples are provided for illustrative purposes only and are not intended to limit the scope of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present disclosure will be better understood from the detailed description and the accompanying drawings, whereby the following applies: Fig. 1 is a side cross-sectional view of an exemplary battery cell; Fig. 2 is a perspective view of an exemplary prismatic battery cell; Fig. Figure 3 is a perspective view of an exemplary prismatic battery cell with a thermal runaway suppression system according to the present disclosure; Fig. 4 is a cross-sectional view taken along line 4-4 of Fig. 3; Fig. 5 is a perspective view of an exemplary partition of the thermal runaway suppression system with a valve configured to control the delivery of a suppressant; Fig. Figure 6 illustrates the release of the suppressant through the valve; Fig. Figure 7A is a cross-sectional view of another exemplary prismatic battery cell with a thermal runaway suppression system according to the present disclosure, wherein the system comprises a vessel insert in which a suppression means is included; Fig. 7B illustrates the vessel insert and an electrode stack of the prismatic battery cell in a common housing; Fig. 7C is a perspective view of the vessel insertion; Fig. 7D is a cross-sectional view along the line 7D-7D of Fig. 7C; Fig. 8 is a cross-sectional view of an exemplary cylindrical battery cell having a thermal runaway suppression system in accordance with the present disclosure; Fig. 9 illustrates the area 9 of Fig. 8 in more detail; and Fig. 10 illustrates an additional thermal runaway suppression system for a prismatic cell according to the present disclosure.

[0026] Reference symbols may be used repeatedly in the drawings to identify similar and / or identical elements. DETAILED DESCRIPTION

[0027] Although the battery cells according to the present disclosure are shown in the context of electric vehicles, the battery cells may be used in stationary applications and / or other applications.

[0028] A thermal runaway suppression system for battery cells according to the present disclosure includes a suppression material configured to actively suppress thermal runaway. The suppression system prevents thermal runaway from spreading to neighboring battery cells and allows specific cells affected by thermal runaway to be replaced without replacing surrounding cells not affected by thermal runaway. The present disclosure also enables battery pack density to be increased.

[0029] With reference now to Fig. 1, a battery cell 10 includes C cathode electrodes 20, A anode electrodes 40, and S separators 32 housed in a casing 50. C, A, and S are integers greater than one. In some examples, A = C+1. The C cathode electrodes 20-1, 20-2, ..., and 20-C include cathode active layers 24 disposed on one or both sides of the cathode current collectors 26. The A anode electrodes 40-1, 40-2, ..., and 40-A include anode active layers 42 disposed on one or both sides of the anode current collectors 46.

[0030] With further reference to Fig. 1 and additional reference to Fig. 2 and Fig. 3, a prismatic battery cell 100 includes a housing 110. In some examples, the housing 110 has a rectangular cross-section. The prismatic battery cell 100 includes outer terminals 112 and 114 and a vent cap 116. A stack 120 of the C cathode electrodes 20, the A anode electrodes 40, and the S separators 32 is disposed within the housing 110. The anode current collectors 46 and / or the cathode current collectors 26 include outer tabs 130 and 132, respectively, which are welded to the inner terminals 140 and 142, respectively, in any suitable manner, e.g., by laser welding, ultrasonic welding, etc. The inner terminals 140 and 142 are connected to the outer terminals 112 and 114, respectively, of the prismatic battery cell 100.

[0031] With further reference to Fig. 3 and additional reference to Fig. 4-6 The prismatic battery cell 100 includes a thermal runaway suppression system 200 according to the present disclosure. The thermal runaway suppression system 200 comprises a partition in the form of a plate 210 within the housing 110 adjacent to the stack 120. The plate 210 is mounted within the housing 110 in any suitable manner to define a chamber 250 configured to accommodate a suppression material 260. For example, the plate 210 may include a flange 212 extending around the outer circumference of the plate 210. The flange 212 is attached to an inner surface of the housing 110 in any suitable manner, e.g., by welding, press-fitting, mechanical locking, bonding, etc. The flange 212 may extend upward, away from the chamber 250, or downward, toward the chamber 250.

[0032] The plate 210 contains a valve configured to release the suppressant material 260 in response to a thermal runaway condition within the stack 120. The valve is configured to open when the pressure within the stack 120 exceeds a predetermined threshold corresponding to the occurrence of thermal runaway, allowing the suppressant material 260 to flow from the chamber 250 into the stack 120. The valve can be configured in any suitable way to control the release of the suppressant material 260. For example, the valve could be a suitable mechanical valve, an electronically controlled valve, etc.The valve can contain a phase-change material that separates the suppression material 260 from the stack 120, and / or a disk made of a shape-memory alloy that is triggered by temperature or pressure to release the suppression material 260 to the stack 120. In the example of . Fig. 4-7 the valve is designed as a 220 tear seam.

[0033] The tear seam 220 extends the entire length of the plate 210 in the illustrated example, but may be positioned in any other suitable manner. The tear seam 220 is suitably formed into the plate 210. For example, the tear seam 220 may be a weakened region of the plate 210 configured to tear or otherwise open when the pressure within the stack 120 exceeds a predetermined threshold corresponding to the presence of thermal runaway at the stack 120, allowing the suppression material 260 to flow from the chamber 250 into the stack 120. The tear seam 220 may also include a bimetallic plate configured to separate or otherwise open (e.g., by deforming) to expose an opening in the plate 210 through which the suppression material 260 can pass.The tear seam 220 can be configured to open at any suitable predetermined pressure, e.g., any suitable pressure lower than the pressure at which the vent cap 116 opens. The vent cap 116 can be configured to open, for example, at 1.0 to 1.5 megapascals. In an exemplary application, the tear seam 220 can be configured to open between 0.75 and 0.85 megapascals, or approximately 0.75 to 0.85 megapascals.

[0034] The suppression material 260 can be any suitable material (e.g., gas, liquid, etc.) configured to prevent thermal runaway within the stack 120. For example, the suppression material 260 can be or contain perfluoro(2-methyl-3-pentanone), which is a fluorinated ketone with the structural formula CF3CF2C(=O)CF(CF3)2 and is a fully fluorinated analogue of ethyl isopropyl ketone. Perfluoro(2-methyl-3-pentanone) is offered, for example, by the 3M Company in St. Paul, Minnesota, under the brand names Novec™ 1230, Novec™ 649, and FK-5-1-12. The suppression material 260 is stored as a pressurized liquid in chamber 250. If the valve, e.g., For example, if the tear seam 220 opens, the suppression material 260 quickly evaporates and enters the stack 120 to prevent the thermal runaway event.More precisely, when the suppression material 260 evaporates, it extracts heat from the stack 120 to reduce the rate of thermal runaway, giving additional time to other thermal runaway mechanisms (e.g., short-circuit interrupt devices, etc.) to suppress the thermal event.

[0035] Fig. Figure 6 illustrates an example of the operation of the suppression system 200 for suppressing thermal runaway. If the pressure within the stack 120 exceeds a predetermined pressure due to a thermal runaway condition, the rupture seam 220 (or another suitable valve) is configured to open to release the suppression material 260 into the stack 120. The liquid suppression material 260 evaporates upon opening of the rupture seam 220 and enters the stack 120, where it suppresses the thermal runaway.

[0036] Fig. Figures 7A-7D illustrate another thermal runaway suppression system 300 according to the present disclosure. The thermal runaway suppression system 300 comprises a vessel 310 containing the suppression material 260. The vessel 310 includes any suitable valve for controlling the release of the suppression material 260 into the stack 120. The vessel 310 may, for example, contain the plate 210 (or a similar plate) with the rupture seam 220. The vessel 310 may contain any other suitable valve configured to release the suppression material 260 in response to a pressure increase within the stack 120 associated with thermal runaway. The vessel 310 may be a self-contained unit that does not include any wall or other surface of the casing 110. The vessel 310 can thus be inserted into the housing 110 to prevent thermal runaway of the stack 120.The vessel 310 can also be configured to be inserted into another suitable housing to prevent thermal runaway within it.

[0037] Fig. 8 and Fig. Figure 9 shows an exemplary cylindrical battery cell 400 with a further thermal runaway suppression system 500 according to the present disclosure. The cylindrical battery cell 400 contains a roll 410 with electrodes, cathodes, and separators, which is referred to as a "jelly roll." The roll 410 is similar to the stack 120 but is rolled up into a cylindrical housing 412. Inside the housing 412 is a plate 210', which is similar to the plate 210 but has a cylindrical shape to fit inside the cylindrical housing 412. Features of the plate 210' that are the same as or similar to those of the plate 210 are described in the Fig. 8 and Fig. 9 with the same reference symbols and the dash symbol ('). The description of the similar features set out above also applies to the configuration of Fig. 8 and Fig. 9, unless otherwise stated.

[0038] The plate 210' comprises a flange 212' which is held in any suitable manner (e.g., by welding, press-fitting, mechanical locking, gluing, etc.) to an interior of the housing 412 to define a chamber 250' for the suppressing material 260, which is similar to chamber 250 but generally circular. The plate 210' can be arranged at any suitable location within the housing 412, for example, towards a bottom of the housing 412, as shown in Fig. 8 and Fig. Figure 9 illustrates this. The plate 210' contains any suitable valve for controlling the discharge of the suppressant material 260 from the housing 412 and into the stack 120. For example, the plate 210' may contain a valve in the form of a rip weld 220' configured to open to discharge the suppressant material 260 in the same manner as described above with respect to the rip weld 220.

[0039] Fig. Figure 10 illustrates an additional suppression system 600 according to the present disclosure. The suppression system 600 can be configured as a replacement for the suppression system 200, the suppression system 300, and / or the suppression system 500. Fig. Figure 10 illustrates the suppression system 600, which is connected to the prismatic battery cell 100 instead of the suppression system 200. The suppression system 600 can also be connected to the cylindrical battery cell 400.

[0040] The suppression system 600 includes a container 610 that is separate from the prismatic battery cell 100 and connected thereto by a conduit 612. The container 610 may be connected to multiple battery cells. For example, and as shown in Fig. As illustrated in Figure 10, the container 610 can be connected to another battery cell 100' via the line 612. The container 610 is configured to hold the suppressor material 260. A suitable valve 614 is located on the prismatic battery cell 100, configured to open in response to a thermal runaway condition at the stack 120. Similarly, the battery cell 100' includes a valve 614'. The following description of the valve 614 also applies to the valve 614'. The valve 614 can be a rupture weld (such as the rupture weld 220), a mechanical valve, an electronically actuated valve, etc. The valve 614 is configured to open when the pressure within the stack 120 exceeds a predetermined threshold corresponding to thermal runaway, e.g., B. 0.75 - 0.85 megapascals or about 0.75 - 0.85 megapascals.When valve 614 opens, the liquid suppressant material 260 flows from inside container 610 into the stack 120 of battery cell 100, where the suppressant material 260 evaporates and suppresses thermal runaway as described above. When valve 614' opens, the liquid suppressant material 260 flows from inside container 610 into the stack 120' of battery cell 100', where the suppressant material 260 evaporates and suppresses thermal runaway.

[0041] In Fig.9. The cylindrical battery cell 400 can also be configured with the suppression system 600 as a replacement for the suppression system 500, thereby eliminating the plate 210' and the suppression material 260 located beneath the plate 210'. For example, the line 612 can be connected to the valve 614, which is positioned at any location to detect pressure changes in the roller 410 caused by thermal runaway in the roller 410. The valve 614 is configured to open when the pressure of the roller 410 exceeds a predetermined threshold corresponding to thermal runaway, e.g., 0.75–0.85 megapascals. When the valve 614 opens, the liquid suppressant material 260 flows from inside the container 610 into the roller 410, where the suppressant material 260 evaporates and suppresses thermal runaway as described above.The container 610 can be connected to multiple battery cells, e.g., multiple cylindrical battery cells, to distribute the suppression material 260 to all battery cells.

[0042] The foregoing description serves only for illustration and is not intended in any way to limit the disclosure, its application, or uses. The comprehensive teachings of the disclosure can be implemented in a multitude of forms. While this disclosure contains certain examples, the actual scope of the disclosure should therefore not be limited to them, since other modifications will become apparent upon examination of the drawings, the description, and the following claims. It should be understood that one or more steps within a process may be carried out in a different order (or simultaneously) without altering the principles of the present disclosure.Although each of the embodiments described above has certain features, one or more of these features described in relation to any embodiment of the disclosure may be implemented in any other embodiment and / or combined with features of those other embodiments, even if such combination is not expressly described. In other words, the described embodiments are not mutually exclusive, and permutations of one or more embodiments among themselves remain within the scope of this disclosure.

[0043] Spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including "connected," "interlocking," "coupled," "adjacent," "next to," "on top of," "above," "below," and "arranged." If a relationship between first and second elements is not explicitly described as "direct" in the above disclosure, this relationship may be a direct relationship, in which no other intervening elements exist between the first and second elements, or an indirect relationship, in which one or more intervening elements (either spatial or functional) exist between the first and second elements.As used herein, the expression “A, B and / or C” should be interpreted using a non-exclusive logical OR operation as logical (A OR-connected with B OR-connected with C) and not as “at least one of A, at least one of B and at least one of C”.

[0044] In the diagrams, the direction of an arrow, as indicated by its tip, generally illustrates the flow of information (e.g., data or instructions) that is relevant to the illustration. For example, if Element A and Element B exchange a variety of information, but the information transferred from Element A to Element B is relevant for the illustration, the arrow may point from Element A to Element B. This unidirectional arrow does not mean that no other information is transferred from Element B to Element A. Furthermore, in the context of information sent from Element A to Element B, Element B may send requests for or acknowledgments of the information to Element A.

Claims

[1] A system configured to suppress thermal runaway in a battery cell, the system comprising: a battery cell stack, including: C cathode electrodes each comprising a cathode current collector, a cathode active layer disposed on the cathode current collector, and an external connector extending from the cathode current collector; A anode electrodes, each comprising an anode current collector, an anode active layer disposed on the anode current collector, and an external connector extending from the anode current collector; and S separators, where C, A and S are integers greater than one; a chamber configured to store therein a suppressant configured to suppress thermal runaway; and a valve configured to open in response to a thermal runaway condition at the battery cell stack to release the suppressant from the chamber into the battery cell stack. [2] The system of claim 1, wherein the battery cell is a prismatic battery cell. [3] The system of claim 1, wherein the battery cell is a cylindrical battery cell. [4] The system of claim 1, wherein the battery cell stack and the chamber are housed in a common housing. [5] The system of claim 1, wherein the chamber is spaced from a housing containing the battery cell stack and is connected to the housing by a conduit. [6] The system of claim 1, further comprising a plate within a housing in which the battery cell stack is received, the plate separating the chamber from the battery cell stack, the valve being contained in the plate. [7] The system of claim 6, wherein the valve includes a tear seam extending along the plate. [8] The system of claim 1, wherein the chamber is configured to store the suppressant as a liquid. [9] The system of claim 8, wherein the suppressant is configured to vaporize after being delivered from the chamber to the battery cell stack. [10] The system of claim 9, wherein the suppressant comprises a fluorinated ketone.

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