Secondary battery module

Abstract

The present invention comprises: a battery cell stack in which a plurality of battery cells are stacked and which is accommodated in a case frame; a bus bar frame including a coupling surface coupled to the case frame so as to cover the battery cell stack and a protruding portion protruding outward from the coupling surface in a direction away from the battery cell stack and having a terminal provided on an upper surface thereof; and an insulating cover including a side cover portion coupled so as to cover an outer side of the protruding portion, and an upper cover portion at a position higher than the protruding portion and disposed inward from the side cover portion so as to expose the terminal, the shielding portion protrudes from the coupling surface of the bus bar frame in the vertical direction so as to shield the terminal and the battery cell stack from each other. According to the present invention having the above configuration, the shielding portion and the upper cover portion close the space between the battery cell stack and the terminal, and therefore, even if a fire occurs in the battery cell stack and dust is generated, contact between the dust and the terminal can be prevented. Therefore, development to thermal runaway can be prevented or ongoing thermal runaway can be delayed.

Description

Technical Field

[0001] This application claims priority to Korean Patent Application No. 10-2023-0136188, filed in Korea on October 12, 2023, the disclosure of which is incorporated herein by reference.

[0002] This disclosure relates to secondary battery modules, and more specifically, to secondary battery modules that can resolve the problem of thermal runaway caused by dust even when dust is generated due to a fire in the battery cell. Background Technology

[0003] In the fields of portable devices and electric vehicles, the demand for high-efficiency rechargeable batteries is rapidly increasing. Among these rechargeable batteries, lithium-ion batteries, which have high energy density, maintain relatively high voltage, and have low self-discharge rates, are commercialized and widely used, and research and development to improve their performance are actively underway.

[0004] Secondary batteries have a structure in which electrode components and electrolyte solution are embedded in a shell such as a can or bag.

[0005] Among these, the pouch-type secondary battery has a structure in which electrode assemblies are mounted in a pouch. In this case, the electrode assembly has a structure in which positive electrodes, separators, and negative electrodes are repeatedly stacked, wherein positive electrode terminals extending from each positive electrode converge together and connect to a positive electrode lead (electrode lead with a positive electrode), and negative electrode terminals extending from each negative electrode converge together and connect to a negative electrode lead (electrode lead with a negative electrode). Furthermore, the ends of the positive and negative electrode leads protrude from the pouch for electrical connection to the outside.

[0006] Furthermore, multiple secondary batteries installed in vehicles, energy storage systems (ESS), etc., are combined to form secondary battery modules to increase output and power storage capacity, and multiple secondary battery modules are combined to form secondary battery packs. In other words, multiple secondary batteries are brought together to manufacture secondary battery modules, and multiple secondary battery modules are brought together to be installed in vehicles, ESS, etc., in a state of being manufactured as secondary battery packs.

[0007] When pouch-type secondary batteries are manufactured into secondary battery modules, the secondary batteries (battery cells) are stacked so that their flat surfaces are in contact with each other, and the secondary batteries are bundled together by means of tape, cables, etc. or by applying adhesive to the contact surfaces to form a battery cell stack 10.

[0008] For reference, compression pads can also be placed between adjacent battery cells 11 to absorb the contraction and expansion of the battery cells in the battery cell stack 10 and reduce heat generation.

[0009] ReferenceFigure 1a The diagram sequentially shows the battery cell stack 10, the battery cell stack 10 housed in the housing frame 20 and connected to the busbar frame 30 in the inward and outward directions, the insulating cover 40 connected to the outside of the busbar frame 30, and the end plate 50 connected to the outside of the insulating cover 40, and refers to... Figure 1b The diagram sequentially shows the state in which the busbar frame 30, insulating cover 40 and end plate 50 are connected to the housing frame 20 while the battery cell stack 10 is mounted on the housing frame 20, a predetermined number of battery cells 11 are stacked such that the electrode leads 12 protrude in the same direction (to both sides or to one side) and the predetermined number of battery cells 11 are set as the battery cell stack 10.

[0010] Furthermore, except for the side surfaces (surfaces formed in the inward and outward directions) from which the electrode leads 12 protrude in the battery cell stack 10, the connecting housing frame 20 covers the upper surface, the lower surface, and the side surfaces formed along the width direction. Additionally, a busbar frame 30, on which busbars 34 are mounted, is installed to cover the exposed side surfaces of the battery cell stack 10 on the side surfaces from which the electrode leads 12 protrude.

[0011] At this point, the slit is perforated in the busbar frame 30, allowing the electrode lead 12 to be connected to the busbar 34 of the busbar frame 30 by welding or the like after passing through the slit. Each busbar 34 is electrically connected to a terminal 33. Therefore, the busbar frame 30 includes a connection surface 32 covering the battery cell stack 10 and having a perforated slit, and includes a protrusion 31 projecting outward from the connection surface 32 so that the protrusion 31 is exposed even when the terminal plate 50 is connected. Furthermore, the terminal 33 is manufactured to rest on the upper surface of the protrusion 31.

[0012] Next, the insulating cover 40 is connected to cover the connecting surface 32 and protrusion 31 of the busbar frame 30 from the outside, and the end plate 50 is connected sequentially to cover the outside of the insulating cover 40.

[0013] On the other hand, since the busbar frame 30 has a protrusion 31 formed in the outward direction, the upper part 1 of the protrusion 31 placed in the insulating cover 40 is made into a simple shape to eliminate interference when the insulating cover 40 is installed.

[0014] In other words, such as Figure 1a As shown, the upper portion 1 of the insulating cover 40 is manufactured with an "L"-shaped cross-section to ensure minimum rigidity. Therefore, as... Figure 1a As shown, in a conventional structure, the battery cell stack 10 and the terminal 33 are manufactured to have an open structure therebetween.

[0015] However, in this structure, if a fire occurs in any of the battery cells 11, the dust generated during the fire may come into contact with the terminal 33, causing an electrical short circuit, thereby progressing towards thermal runaway or further accelerating the ongoing thermal runaway. The dust mentioned herein refers to small dust particles dispersed by the reaction and / or explosion of compounds within the battery cell 11 during a fire.

[0016] More specifically, in the event of thermal runaway in a secondary battery module, it is important to prevent electrical short circuits between the corresponding busbars. Furthermore, since each busbar is connected to terminal 33, and (when multiple secondary battery modules are electrically connected to each other) the terminals 33 of adjacent secondary battery modules are also electrically connected to each other, it is important to prevent short circuits at terminal 30 in order to prevent or delay thermal runaway.

[0017] In particular, as the capacity and output of secondary battery modules installed in vehicles such as cars increase, stability risks also increase. Even in the event of a fire in a secondary battery module, thermal runaway needs to be delayed as much as possible to ensure passenger evacuation time. Summary of the Invention

[0018] Technical issues

[0019] Therefore, this disclosure relates to providing a secondary battery module that can prevent dust generated in the battery cells from causing short circuits at the terminals by isolating the battery cell stack and terminals from each other, so as to suppress or delay the development of thermal runaway to the greatest extent even if a fire occurs in the battery cells.

[0020] Technical solution

[0021] The secondary battery module provided in this disclosure for achieving the above-mentioned objectives includes: a battery cell stack 10 having a plurality of stacked battery cells 11 and being housed in a housing frame 20; a busbar frame 30 including a connection surface 32 connected to the housing frame 20 to cover the battery cell stack 10 and a protrusion 31 protruding outward from the connection surface 32 away from the battery cell stack 10 and having a terminal 33 disposed on an upper surface; and an insulating cover 40 including a side cover portion 41 connected to cover the outside of the protrusion 31 and an upper cover portion 45 disposed further inward than the side cover portion 41 to expose the terminal 33 at a position higher than the protrusion 31, wherein the busbar frame 30 has a shielding portion A1 protruding from the connection surface 32 in the vertical direction to shield the space between the terminal 33 and the battery cell stack 10.

[0022] The upper cover portion 45 includes: a horizontal portion 43 forming a surface parallel to the upper surface of the protrusion 31; and a vertical portion 44 protruding vertically from the upper surface of the horizontal portion 43.

[0023] The shading portion A1 is set to be perpendicular to the horizontal portion 43.

[0024] The vertical portion 44 is positioned at the end facing the housing frame 20.

[0025] The electrode leads 12 protruding from each battery cell 11 are electrically connected to the busbar 34 and connected to the connection surface 32, and the protrusions 31 are positioned at a higher position than the busbar 34 in the vertical direction.

[0026] The shielding part A1 is manufactured separately from the busbar frame 30 and is made of a material with higher heat resistance than the busbar frame 30 and is connected to the busbar frame 30.

[0027] For example, the busbar frame 30 is made of metal or synthetic resin, and the shielding portion A1 is made of fiberglass.

[0028] In addition, the secondary battery module provided in this disclosure also includes a second shielding portion A2, which separates and closes the space between the insulating cover 40 and the busbar frame 30 at a position spaced apart from the protrusion 31 along the width direction.

[0029] The two second shielding portions A2 are formed to be spaced apart from each other when the protrusion 31 is inserted therebetween.

[0030] Furthermore, the second shielding portion A2 includes a first protrusion 46 protruding from the insulating cover 40 and a second protrusion 35 protruding from the busbar frame 30, and the ends of the first protrusion 46 and the second protrusion 35 are arranged to face each other to form the second shielding portion A2.

[0031] Beneficial effects

[0032] Because the space between the battery cell stack and the terminals is closed by the shielding portion and the top cover portion, even if a fire occurs in the battery cell stack and dust is generated, the present disclosure with the above configuration can prevent contact between dust and the terminals. Therefore, it is possible to prevent the development of thermal runaway or delay ongoing thermal runaway.

[0033] In the upper cover section, a horizontal portion can be formed to facilitate connection with the housing frame, and the connection position can be guided by a vertical portion.

[0034] The shielding section can be made of fiberglass independently of the busbar frame to prevent damage caused by high-temperature dust.

[0035] In addition, this disclosure provides a second shielding portion that separates the space between the busbar frame and the insulating cover, thereby further reducing the possibility of dust coming into contact with the terminals. Attached Figure Description

[0036] Figure 1a The diagram sequentially shows the state of the battery cell stack, the state of the battery cell stack being housed in the housing frame and connected to the busbar frame in the inward and outward directions, the state of the insulating cover being connected to the outside of the busbar frame, and the state of the end plate being connected to the outside of the insulating cover.

[0037] Figure 1b It is a diagram showing the sequential state of the busbar frame, insulating cover and end plate connected to the housing frame while the battery cell stack is mounted on the housing frame.

[0038] Figure 2 This is a longitudinal cross-sectional view showing the region where the protrusion is located in the secondary battery module provided in the embodiments of this disclosure.

[0039] Figure 3 This is a longitudinal cross-sectional view showing the region where the shielding portion is located in the secondary battery module provided in the embodiments of this disclosure.

[0040] Figure 4 yes Figure 3 An enlarged view of the longitudinal cross-section shown.

[0041] Figure 5 This is a cross-sectional view showing the area where the shielding portion is located and its surroundings in the secondary battery module provided in the embodiments of this disclosure.

[0042] Figure 6 These figures show the states where, when dust is generated, movement toward the terminal is blocked by the shielding portion (left figure) and the states where movement toward the terminal is blocked by the second shielding portion (right figure), respectively. Detailed Implementation

[0043] The present disclosure will be described in detail below with reference to the accompanying drawings to enable those skilled in the art to readily implement it. However, the present disclosure may be implemented in many different forms and is not limited to the embodiments described herein.

[0044] For clarity of description, parts not related to the description have been omitted, and the same reference numerals are used for the same or similar elements throughout the specification.

[0045] Furthermore, the terms or words used in this disclosure and the appended claims should not be construed as limited to their general or dictionary meanings, but rather as being interpreted based on their meanings and concepts corresponding to the technical aspects of this disclosure, on the basis of allowing the inventors to appropriately define the terms for the best interpretation.

[0046] This disclosure relates to a secondary battery module capable of preventing short circuits caused by dust generated in the battery cell 11 at terminal 33, and embodiments of this disclosure will be described in more detail below with reference to the accompanying drawings.

[0047] Implementation Method 1

[0048] The secondary battery module provided in this embodiment includes a battery cell stack 10, a busbar frame 30, and an insulating cover 40, and a shielding portion A1 is provided on the busbar frame 30 to isolate the terminal 33 and the battery cell stack 10.

[0049] Figure 2 This is a longitudinal cross-sectional view showing the region where the protrusion 31 is located in the secondary battery module provided in the embodiment of this disclosure. Furthermore, Figure 3 A longitudinal cross-sectional view is shown of the region where the shielding portion is located in the secondary battery module provided in the embodiments of this disclosure, and Figure 4 yes Figure 3 An enlarged view of the longitudinal cross-section shown.

[0050] As shown above (refer to the reference) Figure 1a The battery cell stack 10 is configured to have a plurality of stacked battery cells 11 and is housed in a housing frame 20.

[0051] Furthermore, referring to Figures 2 to 4 The busbar frame 30 is configured to include a connecting surface 32 and a protrusion 31. The connecting surface 32 is connected to the housing frame 20 to cover the battery cell stack 10, and the protrusion 31 extends outward from the connecting surface 32 away from the battery cell stack 10 (based on...). Figure 2 It protrudes to the left and has a terminal 33 disposed on its upper surface. Therefore, the connecting surface 32 is positioned between the protrusion 31 and the battery cell stack 10.

[0052] The electrode lead 12 protruding from the battery cell 11 is electrically connected to the busbar 34 and then to the connection surface 32. That is, the slit through which the electrode lead 12 passes is perforated in the connection surface 32, and the electrode lead 12 protrudes outward through the slit and is welded to the busbar 34.

[0053] Furthermore, the protrusion 31 is positioned higher than the busbar 34 along the vertical direction, and each busbar 34 is electrically connected to the terminal 33.

[0054] The insulating cover 40 includes a side cover portion 41 connected to cover the outer side of the protrusion 31 and an upper cover portion 45 configured to expose the terminal 33 at a position higher than the protrusion 31. That is, the upper cover portion is further inward than the side cover portion 41 (based on...). Figure 2 (Set to be closer to the right side of the battery cell stack) so that terminal 33 is exposed.

[0055] Furthermore, the end plate 50 is connected to the outside of the insulating cover 40 to cover the insulating cover 40.

[0056] Furthermore, the busbar frame 30 provided in this embodiment has a shielding portion A1 that protrudes from the connecting surface 32 in the vertical direction to shield the space between the terminal 33 and the battery cell stack 10. At this time, the shielding portion A1 can protrude to the extent that one end of it approaches but does not directly contact the inner wall surface of the housing frame 20, so as to prevent interference when assembling the busbar frame 30 and the housing frame 20.

[0057] Furthermore, in this embodiment, the upper cover portion 45 of the insulating cover 40 is configured to include a horizontal portion 43 forming a surface parallel to the upper surface of the protrusion 31 and a vertical portion 44 protruding vertically from the upper surface of the horizontal portion 43. At this time, the vertical portion 44 is set to face the end of the housing frame 20, and the inner end of the horizontal portion 43, together with the shielding portion A1, closes the space (to prevent dust from moving outward).

[0058] That is, the shielding portion A1 is set perpendicular to the horizontal portion 43, and the ends of the horizontal portion 43 are set to contact each other or have a small gap (sufficient to ensure adequate shielding of dust).

[0059] In addition, the shielding portion A1 can be made of the same material as the busbar frame 30 and integrally formed with the busbar frame 30, but the shielding portion A1 can be made separately and then further connected to the busbar frame 30.

[0060] For example, in the event of a fire, dust may have a temperature of at least 300°C. Therefore, the shielding portion A1 provided in this embodiment can be configured in such a way that it is manufactured separately from the busbar frame 30, made of a material with higher heat resistance than the busbar frame 30, and then further assembled to the busbar frame 30.

[0061] For example, the busbar frame 30 can be made of metal or synthetic resin. Furthermore, the shielding portion A1 is made of glass fiber. Alternatively, the shielding portion A1 can be configured such that, after being integrally manufactured with the busbar frame 30, only the area corresponding to the shielding portion A1 has glass fiber coated (or laminated) on its surface. In this case, the shielding portion A1 and the material coated on it are not limited, as long as the material has heat resistance similar to or higher than that of glass fiber and has electrical insulation properties.

[0062] In addition, the secondary battery module is provided with a positive terminal and a negative terminal. The positive terminal is connected to the positive lead and becomes the positive terminal through the bus bar, and the negative terminal is connected to the negative lead and becomes the negative terminal through the bus bar.

[0063] In this embodiment, the top cover portion 45 and the shielding portion A1 can be provided at both the busbar frame 30 and the insulating cover 40 to prevent dust from contacting both the positive and negative terminals.

[0064] Implementation Method 2

[0065] In addition, this disclosure provides a secondary battery module as embodiment 2, which also includes a second shielding portion A2 to prevent dust moving in the inward and outward directions as well as dust moving in the width direction from flowing into the terminal 33.

[0066] The secondary battery module provided in this embodiment includes a battery cell stack 10, a busbar frame 30 and an insulating cover 40, and includes the shielding portion A1 provided in embodiment 1, and also provides a second shielding portion A2.

[0067] Figure 5 This is a cross-sectional view showing the area where the shielding portion is located and its surroundings in a secondary battery module provided in an embodiment of this disclosure. More specifically, it shows a view taken from a transverse cut and viewed from above. Figure 3 A cross-sectional view of the state of the area indicated by the rectangle in the diagram. Furthermore, Figure 6 The diagrams show the states where, when dust is generated, movement toward terminal 33 is blocked by shielding portion A1 (left diagram) and the states where movement toward terminal 33 is blocked by second shielding portion A2 (right diagram).

[0068] Reference Figure 5 In this embodiment, the secondary battery module further includes a second shielding portion A2 that separates and closes the space between the insulating cover 40 and the busbar frame 30 at a position spaced apart from the protrusion 31 along the width direction.

[0069] The two second shielding portions A2 are formed to be spaced apart from each other when the protrusion 31 is inserted therebetween.

[0070] Furthermore, the second shielding portion A2 includes a first protrusion 46 protruding from the insulating cover 40 and a second protrusion 35 protruding from the busbar frame 30, and the ends of the first protrusion 46 and the second protrusion 35 are arranged to face each other to form the second shielding portion A2.

[0071] Furthermore, similar to shielding portion A1, second shielding portion A2 is also made of a material with higher heat resistance than busbar frame 30 and insulating cover 40.

[0072] In other words, the first protrusion 46 and the second protrusion 35 constituting the second shielding portion A2 can be arranged in such a way that they are made of fiberglass and then connected to each of the busbar frame 30 and the insulating cover 40.

[0073] Alternatively, the second shielding portion A2 may be configured such that the first protrusion 46 and the second protrusion 35 are integrally manufactured with each of the busbar frame 30 and the insulating cover 40, and then only the area corresponding to the second shielding portion A2 is coated on the surface with glass fiber (or another material with higher heat resistance than glass fiber and electrical conductivity).

[0074] In addition, as described above, the secondary battery module provided in this disclosure is provided with a positive terminal and a negative terminal respectively. The positive terminal is connected to the positive lead and becomes a positive terminal through the bus bar, and the negative terminal is connected to the negative lead and becomes a negative terminal through the bus bar.

[0075] In this embodiment, a second shielding portion A2 is also provided at each of the positive and negative terminals to prevent dust from contacting both the positive and negative terminals.

[0076] Because the space between the battery cell stack 10 and the terminal 33 is closed by the shielding portion A1 and the top cover portion 45, even if a fire occurs in the battery cell stack 10 and dust is generated, the present disclosure with the above configuration can prevent dust from contacting the terminal 33. Therefore, the development of thermal runaway can be prevented or delayed.

[0077] In the upper cover portion 45, a horizontal portion 43 may be formed to facilitate connection with the housing frame 20, and the connection position may be guided by the vertical portion 44.

[0078] The shielding part A1 can be made of fiberglass independently of the busbar frame to prevent damage caused by high-temperature dust.

[0079] In addition, this disclosure provides a second shielding portion that separates the space between the busbar frame and the insulating cover, thereby further reducing the possibility of dust coming into contact with the terminals.

[0080] The present disclosure has been described above with respect to a limited number of embodiments and accompanying drawings, but the present disclosure is not limited thereto, and those skilled in the art to which the present disclosure pertains may implement it in various forms within the scope of the technical aspects of the present disclosure and the appended claims and their equivalents.

[0081] [List of reference numerals]

[0082] 10: Battery cell stack

[0083] 11: Battery Cells

[0084] 12: Electrode leads

[0085] 20: Shell frame

[0086] 30: Busbar Frame

[0087] 31: Protrusion

[0088] 33: Terminal

[0089] 40: Insulating cover

[0090] 45: Top Cover

[0091] A1: Covered area

[0092] A2: Second shielding section

Claims

1. A secondary battery module, the secondary battery module comprising: A battery cell stack having multiple stacked battery cells and housed within a housing frame; A busbar frame includes a connecting surface and a protrusion, the connecting surface being connected to the housing frame to cover the battery cell stack, and the protrusion projecting outward from the connecting surface away from the battery cell stack and having terminals disposed on the upper surface; as well as An insulating cover includes a side cover portion and a top cover portion, the side cover portion being connected to cover the outer side of the protrusion, and the top cover portion being disposed further inward than the side cover portion to expose the terminal at a position higher than the protrusion. The busbar frame has a shielding portion that protrudes vertically from the connection surface to shield the space between the terminal and the battery cell stack.

2. The secondary battery module according to claim 1, in, The upper cover portion includes: The horizontal portion forms a surface parallel to the upper surface of the protrusion; and The vertical portion protrudes vertically from the upper surface of the horizontal portion.

3. The secondary battery module according to claim 2, in, The shielding portion is configured to be perpendicular to the horizontal portion.

4. The secondary battery module according to claim 2, in, The vertical portion is positioned at the end facing the housing frame.

5. The secondary battery module according to claim 1, in, The busbar, electrically connected to the protruding electrode leads of each battery cell, is connected to the connection surface, and The protrusion is positioned higher than the busbar along the vertical direction.

6. The secondary battery module according to any one of claims 1 to 5, in, The shielding portion is manufactured separately from the busbar frame and is made of a material with higher heat resistance than the busbar frame and is connected to the busbar frame.

7. The secondary battery module according to claim 6, in, The busbar frame is made of metal or synthetic resin, and the shielding portion is made of fiberglass.

8. The secondary battery module according to claim 1, further comprising: The second shielding portion separates and closes the space between the insulating cover and the busbar frame at a position spaced apart from the protrusion along the width direction.

9. The secondary battery module according to claim 8, in, The two second shielding portions are formed to be spaced apart from each other and the protrusion is inserted between the two second shielding portions.

10. The secondary battery module according to claim 8 or 9, in, The second shielding portion includes a first protrusion protruding from the insulating cover and a second protrusion protruding from the busbar frame, and The ends of the first protrusion and the second protrusion are positioned to face each other to form the second shielding portion.

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