Battery module and battery pack including same

Abstract

A battery module according to one embodiment of the present invention includes a battery cell stack in which a number of battery cells are stacked, a module frame surrounding the battery cell stack, and a fire-extinguishing member interposed between the battery cells, the battery cells including a first battery cell and a second battery cell adjacent to each other, and the fire-extinguishing member surrounds an upper surface of the first battery cell, a space between the first battery cell and the second battery cell, and a lower surface of the second battery cell in a zigzag pattern.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0149626 dated November 3, 2021, and all contents disclosed in the documents of that Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a battery module and a battery pack including the same, and more particularly to a battery module and a battery pack with improved safety. [Background technology]

[0003] In modern society, as the use of portable devices such as mobile phones, laptops, video cameras, and digital cameras has become commonplace, there has been active development of technology related to such mobile devices. In addition, rechargeable secondary batteries are used as the power source for electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (P-HEVs), etc., as a measure to solve air pollution caused by existing gasoline-powered vehicles that use fossil fuels, and so the need for development of secondary batteries is increasing.

[0004] Currently commercially available secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium secondary batteries. Of these, lithium secondary batteries are attracting attention due to the advantages they have over nickel-based secondary batteries, such as almost no memory effect, freedom in charging and discharging, a very low self-discharge rate, and high energy density.

[0005] Such lithium secondary batteries mainly use lithium-based oxides and carbon materials as positive and negative active materials, respectively, and include an electrode assembly in which positive and negative electrode plates coated with the positive and negative active materials are arranged with a separator sandwiched therebetween, and a battery case that hermetically houses the electrode assembly together with an electrolyte.

[0006] In general, lithium secondary batteries are classified according to the shape of their exterior material into can-type secondary batteries in which an electrode assembly is housed in a metal can and pouch-type secondary batteries in which an electrode assembly is housed in a pouch made of an aluminum laminate sheet.

[0007] In the case of secondary batteries used in small devices, 2-3 battery cells are arranged, whereas in the case of secondary batteries used in medium to large devices such as automobiles, a battery module in which a number of battery cells are electrically connected is used. In such battery modules, a number of battery cells are connected to each other in series or parallel to form a battery cell stack, thereby improving capacity and output. In addition, one or more battery modules can be mounted with various control and protection systems such as a BMS (Battery Management System) and a cooling system to form a battery pack.

[0008] If the temperature of a secondary battery rises above the appropriate level, the performance of the secondary battery may deteriorate, and if the temperature rises too much, there is a risk of explosion or fire. In particular, if a thermal runaway phenomenon occurs in a specific battery cell of a secondary battery, it spreads very quickly to adjacent battery cells. In addition, since there is a high possibility of a large-scale fire or explosion occurring due to thermal runaway propagation between battery cells, it is very important to prevent the thermal runaway phenomenon and suppress and delay the thermal runaway propagation.

[0009] FIG. 1 is a diagram showing battery cells and adhesive members included in a conventional battery module.

[0010] 1, the battery cell stack includes battery cells 11 and adhesive members 50a, 50b interposed between adjacent battery cells 11. At this time, the adhesive members 50a, 50b include separate type adhesive members 50a or integral type adhesive members 50b depending on the type.

[0011] That is, in the conventional battery module, the battery cells 11 are attached to each other via adhesive members 50a, 50b, such as double-sided tape, between the battery cells 11 to form a battery cell stack. However, in this case, when a fire occurs in the battery module, it is difficult to delay the spread of the ignition that occurs in some of the battery cells 11 to the other battery cells 11.

[0012] Furthermore, in the case of the adhesive members 50a and 50b, the upper and lower parts of the battery cells 11 are not covered, so heat and flames are easily transferred to adjacent battery cells 11, particularly when thermal runaway occurs.

[0013] Therefore, it is necessary to develop a battery module that can not only cover the upper and lower parts of the battery cells 11, but also suppresses thermal runaway and prevents and delays the propagation of thermal runaway between the battery cells 11, thereby improving safety. Summary of the Invention [Problem to be solved by the invention]

[0014] An object of the present invention is to provide a battery module that prevents or effectively delays the propagation of thermal runaway between battery cells when thermal runaway occurs, and a battery pack including the battery module.

[0015] However, the problems that the present invention is intended to solve are not limited to those mentioned above, and problems not mentioned will be clearly understood by those having ordinary skill in the art to which the present invention pertains from this specification and the attached drawings. [Means for solving the problem]

[0016] A battery module according to one embodiment of the present invention includes a battery cell stack in which a number of battery cells are stacked, a module frame surrounding the battery cell stack, and a fire-extinguishing member interposed between the battery cells, the battery cells including a first battery cell and a second battery cell adjacent to each other, and the fire-extinguishing member surrounds an upper surface of the first battery cell, a space between the first battery cell and the second battery cell, and a lower surface of the second battery cell in a zigzag pattern.

[0017] The extinguishing member may include an extinguishing agent and a case that contains the extinguishing agent.

[0018] The case melts when high temperatures occur inside the battery module, and the fire extinguishing agent contained in the case is released to the outside of the case.

[0019] The fire extinguishing member may have double-sided adhesiveness.

[0020] The case may have double-sided adhesive properties.

[0021] The fire suppression member may contact an upper portion of the module frame and a lower portion of the module frame.

[0022] The fire-extinguishing member of the battery module according to another embodiment of the present invention may be in contact with an upper surface of the first battery cell and a lower surface of the second battery cell.

[0023] The fire extinguishing member can bond an upper portion of the module frame to an upper surface of the first battery cell, and can bond a lower portion of the module frame to a lower surface of the second battery cell.

[0024] The fire extinguishing member can bond the first battery cell and the second battery cell to each other.

[0025] The fire extinguishing member may be interposed between a side portion of the module frame and an outermost battery cell.

[0026] The fire extinguishing member may bond a side portion of the module frame to an outermost battery cell.

[0027] A battery pack according to yet another embodiment of the present invention may include the above-described battery module. Effect of the Invention

[0028] A battery module according to one embodiment of the present invention includes a fire-extinguishing member interposed between a pair of adjacent battery cells in a battery cell stack, and the fire-extinguishing member is formed to surround the battery cells in a zigzag shape, thereby preventing thermal runaway propagation between battery cells or effectively delaying the thermal runaway propagation when thermal runaway occurs.

[0029] The effects of the present invention are not limited to the effects described above, and effects not mentioned will be clearly understood by those having ordinary skill in the art to which the present invention pertains from this specification and the accompanying drawings. [Brief description of the drawings]

[0030] [Figure 1] 1A and 1B are diagrams showing battery cells and adhesive members included in a conventional battery module. [Diagram 2] 1 is a perspective view showing a battery module according to an embodiment of the present invention; [Diagram 3] 3 is a perspective view showing a battery cell included in the battery module of FIG. 2. [Figure 4] FIG. 3 is a diagram showing a cross section taken along the cutting line aa' in FIG. [Diagram 5] FIG. 13 is a diagram showing a battery module according to another embodiment of the present invention. [Figure 6] 6 is a perspective view showing a portion of a battery cell stack included in the battery module of FIG. 5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0031] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings, in which: FIG. 1 is a block diagram of a semiconductor device according to an embodiment of the present invention;

[0032] In order to clearly explain the present invention, parts that are not necessary for the explanation will be omitted, and the same reference numerals will be used throughout the specification to refer to the same or similar components.

[0033] In addition, the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of explanation, and the present invention is not necessarily limited to those shown in the drawings. In the drawings, thicknesses are enlarged to clearly express various layers and regions. In the drawings, thicknesses of some layers and regions are exaggerated for convenience of explanation.

[0034] In addition, when a part such as a layer, film, region, or plate is described as being "on" another part, this includes not only the case where it is "directly on" the other part, but also the case where there is another part in between. Conversely, when a part is described as being "directly on" another part, it means that there is no other part in between. Furthermore, being "on" a reference part means being located above or below the reference part, and does not necessarily mean being located "on" the opposite direction of gravity.

[0035] Also, throughout the specification, when a part is described as "comprising" a certain element, this means that it can further include other elements, but not excluding other elements, unless specifically stated to the contrary.

[0036] Furthermore, throughout the specification, when we refer to "in a plane" we mean when the subject part is viewed from above, and when we refer to "in cross section" we mean when the subject part is cut vertically and viewed from the side.

[0037] The terms "first" and "second" used in this application may be used to describe various components, but the components should not be limited by the terms. The terms are used only to distinguish one component from another.

[0038] The battery module of the present invention will be described below with reference to FIGS.

[0039] Fig. 2 is a perspective view showing a battery module according to an embodiment of the present invention, Fig. 3 is a perspective view showing a battery cell included in the battery module of Fig. 2, Fig. 4 is a diagram showing a cross section taken along the cutting line a-a' of Fig. 2.

[0040] 2 to 4, a battery module 100 according to this embodiment includes a battery cell stack 120 in which a plurality of battery cells 110 are stacked, and a module frame 200 that surrounds the battery cell stack 120.

[0041] First, the battery cell 110 is preferably a pouch-type battery cell and is formed into a rectangular sheet-like structure. For example, referring to Fig. 3, the battery cell 110 according to this embodiment has a structure in which two electrode leads 111 and 112 face each other and protrude from one end 114a and the other end 114b of a cell body 113, respectively. That is, the battery cell 110 includes the electrode leads 111 and 112 protruding in directions facing each other. More specifically, the electrode leads 111 and 112 are connected to an electrode assembly (not shown) and protrude from the electrode assembly (not shown) to the outside of the battery cell 110.

[0042] Meanwhile, the battery cell 110 can be manufactured by bonding both ends 114a, 114b of the cell case 114 to one side 114c connecting them with each other in a state where an electrode assembly (not shown) is housed in the cell case 114. In other words, the battery cell 110 according to this embodiment has a total of three sealing parts 114sa, 114sb, 114sc, and the sealing parts 114sa, 114sb, 114sc are structured to be sealed by a method such as heat fusion, and the remaining other side part is formed of a connecting part 115. The cell case 114 is formed of a laminate sheet including a resin layer and a metal layer.

[0043] Furthermore, the connecting portion 115 may extend long along one peripheral edge of the battery cell 110, and a butt ear 110p is formed at an end of the connecting portion 115. Furthermore, as the cell case 114 is sealed with the protruding electrode leads 111, 112 sandwiched therebetween, a terrace portion 116 is formed between the electrode leads 111, 112 and the cell body 113. In other words, the battery cell 110 may include the terrace portion 116 formed by extending from the cell case 114 in the direction in which the electrode leads 111, 112 protrude.

[0044] Such a battery cell 110 may be configured in a plurality of pieces, and a plurality of battery cells 110 are stacked so as to be electrically connected to each other to form a battery cell stack 120. In particular, as shown in Fig. 2, a plurality of battery cells 110 are stacked in a direction parallel to the x-axis. Thus, the electrode leads 111 and 112 can protrude in the y-axis direction and the -y-axis direction, respectively.

[0045] Meanwhile, the module frame 200 may be a monoframe that surrounds the battery cell stack 120 except for the front and rear surfaces. However, the module frame 200 is not limited thereto, and may include a frame shape including an L-shaped frame or a U-shaped frame with an upper surface, a front surface, and a rear surface that are open and cover the lower and both sides of the battery cell stack 120, and an upper plate that covers the upper portion of the battery cell stack 120. The battery cell stack 120 accommodated inside the module frame 200 can be physically protected through the module frame 200. In this case, the module frame 200 may include a lower portion 200a of the module frame 200, a side portion 200b of the module frame 200, and an upper portion 200c of the module frame 200.

[0046] The end plates 150 can cover the front and rear surfaces of the battery cell stack 120 that are exposed by the module frame 200. The end plates 150 can be joined to the front and rear end corners of the module frame 200 by welding.

[0047] A bus bar frame (not shown) is formed between the end plates 150 and the front and rear surfaces of the battery cell stack 120. A plurality of bus bars attached to the bus bar frame protrude from the battery cells 110 and can contact the electrode leads 111 and 112 attached to the bus bar frame.

[0048] In addition, the battery module 100 according to this embodiment further includes a thermally conductive resin layer 310 located between the lower surface of the battery cell stack 120 and the lower portion 200a of the module frame 200, and the thermally conductive resin layer 310 can play a role in transferring heat generated in the battery cells 110 to the bottom of the battery module 100.

[0049] Meanwhile, referring to FIG. 4, the battery module 100 according to this embodiment includes a fire extinguishing member 300 interposed between the battery cells 110 .

[0050] At this time, the battery cells 110 include a first battery cell 110a and a second battery cell 110b adjacent to each other. In addition, the first battery cell 110a is formed next to the second battery cell 110b so that they are adjacent to each other. Therefore, the first battery cells 110a and the second battery cells 110b are formed alternately.

[0051] 4, the fire extinguishing member 300 surrounds the upper surface of the first battery cell 110a, the space between the first battery cell 110a and the second battery cell 110b, and the lower surface of the second battery cell 110b in a zigzag shape. That is, the fire extinguishing member 300 can surround the upper surface of the first battery cell 110a and the lower surface of the second battery cell 110b, and is formed to surround the space between the first battery cell 110a and the second battery cell 110b. In particular, since the first battery cell 110a and the second battery cell 110b can be formed alternately, the fire extinguishing member 300 can surround each of the spaces between the first battery cell 110a and the second battery cell 110b that are formed alternately.

[0052] At this time, the extinguishing member 300 may include an extinguishing agent and a case for accommodating the extinguishing agent. The extinguishing member 300 shown in Fig. 4 is the case. Therefore, the extinguishing agent is formed inside the case of the extinguishing member 300.

[0053] The case melts when high temperature occurs inside the battery module 100 and the battery cells 110, and the extinguishing agent housed in the case can be discharged to the outside of the case. In particular, the case melts when thermal runaway occurs inside the battery module 100. At this time, the extinguishing agent discharged from the case can prevent the thermal runaway phenomenon occurring in the battery cells 110 and delay the propagation of the thermal runaway. In addition, the extinguishing agent can suppress the fire and flames, thereby preventing and delaying the propagation of the fire and flames to the adjacent battery cells 110.

[0054] Therefore, the case is formed of a material that can melt when a thermal runaway phenomenon occurs. The extinguishing agent may be a liquid extinguishing agent and / or a commonly used powder-type extinguishing agent. As an example, the extinguishing agent material may be a liquid extinguishing agent including a foam extinguishing agent, and may be any one of sodium bicarbonate (NaHCO3), potassium bicarbonate (KHCO3), ammonium phosphate (NH4H2PO3), and a mixture of potassium bicarbonate (KHCO3) and urea ((NH2)2CO). However, the extinguishing agent is not limited thereto, and any material that performs a fire extinguishing function may be used without restriction.

[0055] In addition, the fire extinguishing member 300 may have double-sided adhesiveness. In particular, the case of the fire extinguishing member 300 may have double-sided adhesiveness. Therefore, as described below, the case can serve to fix the first battery cell 110a and the second battery cell 110b formed on both sides of the fire extinguishing member 300 around the fire extinguishing member 300.

[0056] 4, the fire extinguishing member 300 can be in contact with the upper portion 200c of the module frame 200 and the lower portion 200a of the module frame 200. Since the thermally conductive resin layer 310 can be formed on the lower portion 200a of the module frame 200, the fire extinguishing member 300 can be in contact with the thermally conductive resin layer 310.

[0057] Furthermore, the fire extinguishing member 300 is formed to surround the space between the first battery cell 110a and the second battery cell 110b and can be formed to be interposed between the first battery cell 110a and the second battery cell 110b, thereby allowing the first battery cell 110a and the second battery cell 110b to be adhered to each other.

[0058] In addition, the fire extinguishing member 300 can be interposed between the side surface portion 200b of the module frame 200 and the outermost battery cell 110. In other words, the fire extinguishing member 300 is formed so as to be in contact with the side surface portion 200b of the module frame 200, and is also formed so as to be in contact with the side surface of the outermost battery cell 110. Therefore, the fire extinguishing member 300 can bond the side surface portion 200b of the module frame 200 and the outermost battery cell 110 included in the battery cell stack 120, and can fix the battery cell stack 120 inside the module frame 200.

[0059] As a result, when a fire or thermal runaway phenomenon occurs in the battery module 100 according to the present embodiment, the fire-extinguishing member 300 is located on the upper or lower part of the battery cell 110 and is interposed between the adjacent battery cells 110, thereby effectively suppressing the flame generated in the battery cell 110. In addition, carbon dioxide and water vapor may be generated during the process of extinguishing the flame generated in the battery cell 110 by the fire-extinguishing member 300. This reaction can absorb the heat of the thermal runaway phenomenon generated in the battery cell 110 through an endothermic reaction and can also block the supply of oxygen, effectively delaying the flame and heat propagation between the battery cells 110. In addition, the safety of the battery module 100 can be improved.

[0060] Hereinafter, a battery module according to another embodiment of the present invention will be described with reference to Figures 5 and 6. Since some of the contents overlap with those described above, the differences will be mainly described.

[0061] Fig. 5 is a diagram showing a battery module according to another embodiment of the present invention, and Fig. 6 is a perspective view showing a part of a battery cell stack included in the battery module of Fig. 5.

[0062] 5, the fire extinguishing member 300 may be in contact with the upper portion 200c and the lower portion 200a of the module frame 200. In addition, since the thermally conductive resin layer 310 may be formed on the lower portion 200a of the module frame 200, the fire extinguishing member 300 may be in contact with the thermally conductive resin layer 310.

[0063] Also, referring to FIGS. 5 and 6, the fire extinguishing member 300 of this embodiment may contact the upper surface of the first battery cell 110a and the lower surface of the second battery cell 110b.

[0064] Therefore, as described above, the fire extinguishing member 300 has double-sided adhesive properties, and can therefore adhere the upper part 200c of the module frame 200 to the upper surface of the first battery cell 110a, and the lower part 200a of the module frame 200 to the lower surface of the second battery cell 110b.

[0065] In addition, the fire extinguishing member 300 is formed so as to surround the space between the first battery cell 110a and the second battery cell 110b and to be interposed between the first battery cell 110a and the second battery cell 110b, thereby allowing the first battery cell 110a and the second battery cell 110b to be adhered to each other.

[0066] At this time, the battery cells 110 can be fixed to each other by the adhesion, and the battery cell stack 120 formed by stacking a plurality of the battery cells 110 is fixed onto the module frame 200 .

[0067] As a result, the battery cells 110 can be isolated from each other via the fire extinguishing member 300 surrounding the battery cells 110 in a zigzag shape. Therefore, even if a thermal runaway phenomenon occurs in one battery cell 110, the thermal runaway phenomenon can be suppressed via the fire extinguishing member 300, and the propagation of the thermal runaway phenomenon can be delayed. In addition, by bonding and fixing the battery cell stack 120 and the battery cells 110 formed in the module frame 200, movement and damage caused by the battery cell stack 120 and the battery cells 110 can be minimized, and the stability of the battery module can be improved.

[0068] A battery pack according to still another embodiment of the present invention will now be described.

[0069] The battery pack according to the present embodiment includes the battery module described above. In addition, the battery pack of the present invention may be structured by packing one or more battery modules according to the present embodiment together with a battery management system (BMS) for managing the temperature and voltage of the battery, a cooling device, and the like.

[0070] The battery pack can be applied to various devices, including vehicles such as electric bicycles, electric cars, and hybrid cars, but the present invention is not limited thereto and can be applied to various devices that can use a battery module, which also fall within the scope of the present invention.

[0071] Although the preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the above-mentioned specific embodiments, and various modifications may be made by a person having ordinary skill in the art to which the invention pertains without departing from the gist of the present invention as claimed in the claims. However, such modifications should not be understood individually from the technical ideas and perspectives of the present invention. [Explanation of symbols]

[0072] 100: Battery module 110: Battery cell 120: Battery cell stack 150: End plate 200:Module frame 300: Fire extinguishing materials

Claims

1. a battery cell stack in which a plurality of battery cells are stacked; a module frame surrounding the battery cell stack; a fire extinguishing member interposed between the battery cells; the battery cells include a first battery cell and a second battery cell adjacent to each other; the fire extinguishing member surrounds an upper surface of the first battery cell, a space between the first battery cell and the second battery cell, and a lower surface of the second battery cell in a zigzag pattern; The fire extinguishing member is in contact with an upper portion and a lower portion of the module frame.

2. The fire extinguishing member is Fire extinguishing agent; The battery module according to claim 1 , further comprising a case for accommodating the fire extinguishing agent.

3. The case melts when high temperatures occur inside the battery module, The battery module according to claim 2 , wherein the extinguishing agent contained in the case is discharged to the outside of the case.

4. The battery module according to claim 2 , wherein the fire extinguishing member has double-sided adhesiveness.

5. The battery module according to claim 4 , wherein the case has double-sided adhesive properties.

6. The battery module according to claim 1 , wherein the fire extinguishing member is in contact with an upper surface of the first battery cell and a lower surface of the second battery cell.

7. The battery module according to claim 1 , wherein the fire extinguishing member bonds an upper portion of the module frame to an upper surface of the first battery cell and bonds a lower portion of the module frame to a lower surface of the second battery cell.

8. The battery module according to claim 1 , wherein the fire extinguishing member bonds the first battery cell and the second battery cell to each other.

9. The battery module according to claim 1 , wherein the fire extinguishing member is interposed between a side portion of the module frame and an outermost battery cell.

10. The battery module according to claim 9 , wherein the fire extinguishing member bonds a side portion of the module frame to an outermost battery cell.

11. A battery pack comprising the battery module according to any one of claims 1 to 10.

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