Battery module and battery pack including same

Abstract

A battery module according to an embodiment of the present invention includes: a cell stack formed by stacking a plurality of battery cells vertically; a module housing including a base plate supporting the cell stack and a pair of side plates covering both sides of the cell stack; and a bus bar frame assembly covering an opening formed on one longitudinal side of the module housing, wherein each of the pair of side plates includes a plurality of spark delay protrusions formed in a protruding form on an inner surface of the side plate, and a plurality of spark delay recesses formed in a recessed form on the inner surface of the side plate.

Description

[Technical field]

[0001] The present invention relates to a battery module, a battery pack including the battery module, and an ESS (Energy Storage System) and a vehicle including the battery pack. More specifically, the present invention relates to a battery module having a structure that can prevent a fire from occurring inside the battery module by releasing gas to the outside when venting of a battery cell occurs, while suppressing the outflow of sparks including high-temperature electrode active material and metal particles to the outside of the battery module, and further blocking the inflow of oxygen into the battery module, and a battery pack including the battery module, and an ESS and a vehicle including such a battery pack.

[0002] This application claims priority to Korean Patent Application No. 10-2021-0003529 filed on January 11, 2021, the entire contents of which are incorporated herein by reference in their entirety in the specification and drawings. [Background technology]

[0003] A battery pack applied to an ESS and / or an electric vehicle may be manufactured in a form including a plurality of battery modules using lithium secondary batteries capable of realizing high output and high capacity. In order to satisfy the output characteristics of the battery pack required by the ESS and / or an electric vehicle and to realize high capacity, the number of lithium secondary batteries included in one battery module may be increased, and further the number of battery modules included in one battery pack may be increased.

[0004] However, in the case of a battery pack including a large number of lithium secondary batteries, if a fire or explosion occurs, the damage caused by the fire or explosion becomes greater.

[0005] Fires in battery packs start when the temperature of a lithium secondary battery inside a battery module rises abnormally and generates internal gas. If the temperature of the lithium secondary battery rises abnormally and the internal gas is generated, causing the internal pressure of the lithium secondary battery to rise above a certain level, venting occurs in the lithium secondary battery, which causes high-temperature gas to be ejected to the outside of the lithium secondary battery, and high-temperature sparks containing electrode active material and aluminum particles to be ejected.

[0006] In order to ensure the safety of the battery module and / or the battery pack during use, the venting gas must be quickly discharged to the outside of the battery module when an event occurs so that the internal pressure of the battery module does not increase any further. However, if high-temperature sparks are discharged to the outside of the battery module together with the venting gas, the venting gas, the high-temperature sparks, and oxygen may react to cause a fire.

[0007] Therefore, there is a need to develop a battery module having a structure that can quickly discharge venting gas to the outside of the battery module even if thermal runaway occurs due to an abnormal phenomenon such as a short circuit inside a battery cell, while effectively preventing high-temperature sparks containing electrode active material and aluminum particles from leaking to the outside.

[0008] In addition, if a structure such as a bus bar frame applied to prevent short circuits between multiple lithium secondary batteries is damaged by continuous contact with high-temperature gas and sparks, oxygen may easily flow from the outside to the inside of the battery module, which may cause a fire to spread to the inside of the battery module. In addition, if the bus bar frame is damaged, the electrode leads of adjacent lithium secondary batteries that have been kept separated by the bus bar frame may come into contact with each other, which may cause the event to spread.

[0009] Therefore, there is a need to develop a battery module having a structure that can block the inflow of external oxygen even if some structures are damaged by high-temperature gas and sparks, and can prevent a short circuit from occurring between adjacent lithium secondary batteries, thereby preventing the event from spreading. Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a battery module having a structure that can quickly exhaust venting gas when an internal event occurs, while effectively preventing high-temperature sparks from escaping to the outside, and further, can block external air from flowing into the inside of the battery module after the venting gas has been exhausted.

[0011] Another object of the present invention is to provide a battery module having a structure that can prevent external oxygen from easily flowing into the inside of the battery module even if some structures are damaged by high-temperature gas and sparks, and can prevent short circuits from occurring between adjacent lithium secondary batteries.

[0012] The technical problems to be solved by the present invention are not limited to the above problems, and other problems will be clearly understood by those skilled in the art from the following description of the invention. [Means for solving the problem]

[0013] In order to achieve the above object, a battery module according to one aspect of the present invention includes a cell stack formed by stacking a plurality of battery cells vertically, a module housing including a base plate supporting the cell stack and a pair of side plates covering both sides of the cell stack, and a bus bar frame assembly covering an opening formed on one longitudinal side of the module housing, each of the pair of side plates including a plurality of spark delay protrusions formed in a protruding form on an inner surface of the side plate, and a plurality of spark delay recesses formed in a recessed form on the inner surface of the side plate.

[0014] Each of the pair of side plates may include a spark redirection portion formed by bending one side end of the side plate in the longitudinal direction toward the cell stack.

[0015] The opening may be formed between a pair of spark redirectors provided on each of the pair of side plates, and an electrode lead of the battery cell may be exposed to the outside of the module housing through the opening.

[0016] The busbar frame assembly may include a busbar frame covering the opening and having a plurality of frame slits through which electrode leads of the battery cells pass, and at least one busbar disposed on an outer surface of the busbar frame and coupled to an electrode lead that has passed through the frame slits.

[0017] The battery module may further include a fire protection sheet assembly interposed between the bus bar frame assembly and the cell stack and coupled to the bus bar frame assembly.

[0018] The fireproof sheet assembly may include a fireproof sheet having a plurality of sheet slits through which the electrode leads of the battery cells pass.

[0019] The fireproof sheet assembly may further include a sheet cover that covers the fireproof sheet and has a plurality of cover slits through which electrode leads of the battery cells pass.

[0020] The fireproof sheet may be a mica sheet.

[0021] The sheet cover may be formed to completely cover the mica sheet so that the mica sheet is not exposed to the outside air.

[0022] The cover slit may have a shape in which its width gradually narrows along a direction toward the bus bar frame assembly.

[0023] The spark delay protrusion and the spark delay recess may extend along a height direction of the side plate and may extend a length corresponding to a stacking height of the cell stack.

[0024] The spark delay protrusions and the spark delay recesses may be alternately formed along a longitudinal direction of the side plate from a center to one side end.

[0025] In order to achieve the above object, a battery pack according to another aspect of the present invention includes the battery module according to the above-mentioned aspect of the present invention.

[0026] In order to achieve the above object, an ESS according to yet another aspect of the present invention includes the battery pack according to the above aspect of the present invention.

[0027] In order to achieve the above object, a vehicle according to yet another aspect of the present invention includes the battery pack according to the above-mentioned aspect of the present invention. Effect of the Invention

[0028] According to one aspect of the present invention, even if some structures are damaged by high-temperature gas and sparks due to an event, the venting gas can be quickly discharged while effectively preventing high-temperature sparks from escaping to the outside, and after the venting gas is discharged, the outside air can be prevented from flowing into the inside of the battery module.

[0029] In addition, according to one aspect of the present invention, even if some structures are damaged by high-temperature gas and sparks, external oxygen cannot easily flow into the inside of the battery module, and short circuits can be prevented from occurring between adjacent lithium secondary batteries.

[0030] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention, serve to further understand the technical ideas of the present invention. Therefore, the present invention should not be interpreted as being limited only to the matters described in the drawings. [Brief description of the drawings]

[0031] [Figure 1] 1 is a diagram illustrating a battery module according to an embodiment of the present invention. [Diagram 2] 2 is a plan view showing the battery module shown in FIG. 1 with a bus bar frame assembly and a fire protection sheet assembly removed. FIG. [Diagram 3] FIG. 2 is a partial cross-sectional view of the battery module shown in FIG. [Figure 4] FIG. 2 is a diagram showing the bus bar frame assembly and fire protection sheet assembly of the present invention coupled to a module housing. [Diagram 5] FIG. 2 is an exploded perspective view showing a portion of the module housing, a bus bar frame assembly, and a fire protection sheet assembly of the present invention. [Figure 6] FIG. 1 shows a fire retardant sheet assembly of the present invention. [Figure 7]4 is a diagram showing the shape of an inner surface of a side plate constituting a module housing of the present invention. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings. Prior to this, the terms and words used in this specification and claims should not be interpreted as being limited to their ordinary and dictionary meanings, but should be interpreted as being in accordance with the meaning and concept of the technical idea of ​​the present invention, in accordance with the principle that the inventor himself can appropriately define the concept of the term in order to best describe the invention. Therefore, it should be understood that the embodiment described in this specification and the configuration shown in the drawings are merely the most preferred embodiment of the present invention, and do not represent the entire technical idea of ​​the present invention, and therefore there may be various equivalents and modifications that can be substituted for them at the time of this application.

[0033] 1 to 3, a battery module according to an embodiment of the present invention includes a cell stack formed by stacking a plurality of battery cells 100 in a vertical direction (parallel to the Z-axis), a module housing 200 that accommodates the cell stack, and a bus bar frame assembly 300 that covers an opening formed on one side in a longitudinal direction (parallel to the X-axis) of the module housing 200. In addition to the above-mentioned components, the battery module may further include a fireproof sheet assembly 400 that is interposed between the bus bar frame assembly 300 and the cell stack and is coupled to the bus bar frame assembly 300.

[0034] A pouch-type battery cell may be applied as the battery cell 100. In this case, the battery cell 100 includes an electrode assembly (not shown), a pouch case 110 that houses the electrode assembly, and a pair of electrode leads 120 that are connected to the electrode assembly and extended to the outside of the pouch case 110. The pair of electrode leads 120 are extended in opposite directions along the longitudinal direction of the battery cell 100 (parallel to the X-axis).

[0035] The module housing 200 includes a base plate 210 that supports the cell stack, and a pair of side plates 220 that cover both sides of the cell stack. The pair of side plates 220 may include a spark redirection portion 200a formed by bending one end of the longitudinal direction toward the cell stack.

[0036] An opening formed on one side of the longitudinal direction of the module housing 200 is formed between a pair of spark redirecting portions 200a provided on each of a pair of side plates 220. The electrode lead 120 of the battery cell 100 may be exposed to the outside of the module housing 200 through the opening formed between the pair of spark redirecting portions 200a.

[0037] The battery module according to an embodiment of the present invention includes the spark redirection unit 200a as described above, thereby preventing high-temperature sparks emitted during venting of the battery cells 100 from being discharged to the outside of the module housing 200 along the longitudinal direction of the module housing 200. That is, during venting of the battery cells 100, high-temperature sparks emitted from both sides in the width direction (direction parallel to the Y axis) of each battery cell 100 constituting the cell stack move toward one end and / or the other end of the longitudinal direction (direction parallel to the X axis) of the battery module, and then the moving direction is changed to a direction toward the cell stack (see the arrow direction shown in FIG. 2). As a result, the spark redirection unit 200a prevents sparks from being discharged to the outside of the battery module from the openings on both sides in the longitudinal direction (direction parallel to the X axis) of the module housing 200.

[0038] 7, the side plate 220 of the module housing 200 includes a plurality of spark delay protrusions 220a and a plurality of spark delay recesses 220b in addition to the spark redirection portion 200a described above. The spark delay protrusions 220a are provided in a protruding form on the inner surface of the side plate 220. The spark delay recesses 220b are provided in a recessed form on the inner surface of the side plate 220.

[0039] The spark delay protrusion 220a and the spark delay recess 220b extend along the height direction (direction parallel to the Z-axis) of the side plate 220. The spark delay protrusion 220a and the spark delay recess 220b extend to a length corresponding to the stacking height of the cell stack.

[0040] The spark delay protrusions 220a and the spark delay recesses 220b may be alternately formed from the center to one end along the longitudinal direction (parallel to the X-axis) of the side plate 220. Similarly, the spark delay protrusions 220a and the spark delay recesses 220b may be alternately formed from the center to the other end along the longitudinal direction (parallel to the X-axis) of the side plate 220.

[0041] The spark delay protrusion 220a and the spark delay recess 220b extend the path of the sparks including the electrode active material and aluminum particles ejected from both sides in the width direction (direction parallel to the Y axis) of the battery cell 100 and move along the longitudinal direction (direction parallel to the X axis) of the side plate 220, and obstruct the path of the sparks. Therefore, the spark delay protrusion 220a and the spark delay recess 220b, together with the above-mentioned spark redirection part 200a, can prevent the sparks from flowing out to the outside of the battery module through the openings formed on both sides in the longitudinal direction (direction parallel to the X axis) of the module housing 200. The battery module according to an embodiment of the present invention may include only the spark delay protrusion 220a and the spark delay recess 220b without including the above-mentioned spark redirection part 200a.

[0042] The module housing 200 may further include a fastening frame 230 that connects the pair of spark redirection parts 200a together and has an open center. The fastening frame 230 is located between the bus bar frame assembly 300 and the fire protection sheet assembly 400. When the fastening frame 230 is provided, the bus bar frame assembly 300 and the fire protection sheet assembly 400 are in close contact with the fastening frame 230 and may be fastened to each other through the open center of the fastening frame 230.

[0043] Meanwhile, although not shown, the openings provided in the module housing 200 of the present invention may be formed on both sides in the longitudinal direction of the module housing 200. In this case, the pair of spark redirecting portions 200a may also be provided on both sides in the longitudinal direction of the module housing 200.

[0044] 1 to 5, the bus bar frame assembly 300 includes a bus bar frame 310 and at least one bus bar 320. The bus bar frame assembly 300 may be provided in a pair, in which case each of the pair of bus bar frame assemblies 300 covers an opening formed on one side and an opening formed on the other side of the module housing 200 in the longitudinal direction (direction parallel to the X-axis).

[0045] The bus bar frame 310 covers an opening formed in the module housing 200 and includes a plurality of frame slits 310b through which the electrode leads 120 of the battery cells 100 pass. The bus bar frame 310 may further include at least one frame protrusion 310a for coupling with the fireproof sheet assembly 400.

[0046] The bus bar frame 310 has a shape corresponding to one end and / or the other end of the module housing 200 in the longitudinal direction and is closely attached to the module housing 200. When the module housing 200 includes the fastening frame 230 as described above, the bus bar frame 310 is closely attached to the spark redirection part 200a and the fastening frame 230.

[0047] The busbar 320 is disposed on an outer surface of the busbar frame 310 and is coupled to the electrode leads 120 passing through the frame slits 310b, thereby electrically connecting a plurality of battery cells 100. The busbar 320 may have busbar slits 320b through which the electrode leads 120 pass. In this case, the busbar slits 320b and the frame slits 310b may be formed at positions corresponding to each other.

[0048] 1 to 6, the fire protection sheet assembly 400 includes a fire protection sheet 410 and a sheet cover 420. The number of the fire protection sheet assemblies 400 may be the same as the number of the bus bar frame assemblies 300.

[0049] A mica sheet that can withstand high-temperature venting gas and sparks and can also withstand fire can be used as the fireproof sheet 410. The fireproof sheet 410 has a plurality of sheet slits 410b through which the electrode leads 120 pass.

[0050] The fireproof sheet 410 can maintain its structure even if the resin busbar frame 310 is damaged by high-temperature venting gas and sparks, thereby allowing the electrode leads 120 inserted into the sheet slits 410b to maintain their positions. In addition, the fireproof sheet 410 can exhaust high-temperature venting gas to the outside through gaps between the sheet slits 410b and the electrode leads 120, while minimizing the emission of high-temperature sparks containing active material and aluminum particles to the outside. In addition, the fireproof sheet 410 prevents oxygen from easily flowing in from the outside of the battery module even if the resin busbar frame 310 is damaged.

[0051] Therefore, the fireproof sheet 410 can minimize the possibility of a fire occurring near the busbar frame 310 even in a situation where an event occurs inside the battery module, and can delay the phenomenon of the fire spreading inside the battery module even if a fire occurs near the busbar frame 310. In addition, the fireproof sheet 410 can prevent the event from spreading due to a short circuit occurring between the battery cells 100 caused by damage to the busbar frame 310.

[0052] The sheet cover 420 completely covers the fireproof sheet 410 so that the fireproof sheet 410 is not exposed to the outside. This is because the mica fireproof sheet 410 has hygroscopicity, and therefore when the mica fireproof sheet 410 is exposed to the outside air of the sheet cover 420, it absorbs moisture, and if it absorbs moisture, there is a risk that its insulating performance will be reduced.

[0053] The seat cover 420 may be a resin injection molding, in which case the fireproof sheet 410 may be disposed in the seat cover 420 by insert injection. The seat cover 420 includes a plurality of cover slits 420b through which the electrode leads 120 pass. The cover slits 420b may have a shape in which the width thereof gradually narrows along a direction toward the busbar frame assembly 300.

[0054] This is because, when the sheet cover 420 made of injected resin melts due to high-temperature venting gas and sparks, the cover slits 420b are quickly closed to prevent air from entering from outside the battery module. If the inflow of outside air is quickly blocked in this manner, the supply of oxygen to the inside of the battery module is cut off, thereby preventing the spread of fire inside the battery module.

[0055] The cover slit 420b, the sheet slit 410b and the frame slit 310b are formed at positions corresponding to each other.

[0056] When the busbar frame 310 has a frame protrusion 310a, the fireproof sheet 410 and the sheet cover 420 are formed at a position corresponding to the frame protrusion 310a for fastening to the busbar frame 310 and are provided with at least one sheet hole 410a and cover hole 420a, respectively, having a corresponding shape.

[0057] In the present invention, the fireproof sheet assembly 400 is illustrated only including the fireproof sheet 410 and the sheet cover 420 covering it, but the present invention is not limited thereto, and the fireproof sheet assembly 400 may be composed of only the fireproof sheet 410, omitting the sheet cover 420.

[0058] Meanwhile, a battery pack according to an embodiment of the present invention includes a battery module according to an embodiment of the present invention as described above. The battery pack may include a plurality of battery modules. An ESS according to an embodiment of the present invention includes a battery pack according to an embodiment of the present invention as described above. A vehicle according to an embodiment of the present invention includes a battery pack according to an embodiment of the present invention as described above. The vehicle includes an electric vehicle.

[0059] As described above, the present invention has been described using limited embodiments and drawings. However, the present invention is not limited thereto, and it goes without saying that various modifications and variations can be made by a person having ordinary knowledge in the technical field to which the present invention pertains within the scope of the technical spirit of the present invention and the equivalent scope of the claims. [Explanation of symbols]

[0060] 100···Battery Cells 110 ···Pouch case 120 Electrode lead 200 ···Module housing 200a Spark redirection section 210···Base plate 220 ···Side plate 220a Spark delay protrusion 220b Spark delay recess 300 Busbar Frame Assembly 310 Busbar frame 310a Frame protrusion 310b Frame slit 320···Busbar 320b Busbar slit 400 ···Fireproof sheet assembly 410 Fireproof sheet 410b Sheet slit 420 ···Seat cover 420b ···Cover slit

Claims

1. A cell stack formed by stacking a plurality of battery cells vertically; a module housing including a base plate supporting the cell stack and a pair of side plates covering both sides of the cell stack; a bus bar frame assembly covering an opening formed on one side of the module housing in a longitudinal direction, Each of the pair of side plates is A plurality of spark delay protrusions formed on an inner surface of the side plate in a protruding form; a plurality of spark delay recesses formed in a recessed configuration on an inner surface of the side plate; Each of the inner surfaces of the pair of side plates moves venting gas generated within the module housing along the longitudinal direction, the spark delay protrusion and the spark delay recess extend and impede the travel path of the venting gas; The spark delay protrusion and the spark delay recess are The side plate has a shape extending along the height direction and is extended with a length corresponding to the stacking height of the cell stack. Battery module.

2. A cell stack formed by stacking a plurality of battery cells vertically; a module housing including a base plate supporting the cell stack and a pair of side plates covering both sides of the cell stack; a bus bar frame assembly covering an opening formed on one side of the module housing in a longitudinal direction, Each of the pair of side plates is A plurality of spark delay protrusions formed on an inner surface of the side plate in a protruding form; a plurality of spark delay recesses formed in a recessed configuration on an inner surface of the side plate; Each of the pair of side plates is A spark direction changing portion is provided, the spark direction changing portion being formed by bending one side end portion of the spark direction changing portion toward the cell stack, The spark delay protrusion and the spark delay recess are The side plate has a shape extending along the height direction and is extended with a length corresponding to the stacking height of the cell stack. Battery module.

3. The opening is formed between a pair of spark redirecting portions provided on each of the pair of side plates, an electrode lead of the battery cell is exposed to the outside of the module housing through the opening; The battery module according to claim 2 .

4. The bus bar frame assembly includes: a bus bar frame covering the opening and including a plurality of frame slits through which the electrode leads of the battery cells pass; at least one bus bar disposed on an outer surface of the bus bar frame and coupled to an electrode lead passing through the frame slit; The battery module according to claim 1 .

5. The battery module includes: a fire protection sheet assembly interposed between the bus bar frame assembly and the cell stack and coupled to the bus bar frame assembly. The battery module according to any one of claims 1 to 4.

6. The fireproof sheet assembly comprises: a fireproof sheet having a plurality of sheet slits through which the electrode leads of the battery cell pass; The battery module according to claim 5 .

7. The fireproof sheet assembly comprises: The battery cell further includes a sheet cover having a plurality of cover slits through which the electrode leads of the battery cell pass, the sheet cover covering the fireproof sheet. The battery module according to claim 6.

8. The fireproof sheet is It is a mica sheet. The battery module according to claim 6 or 7.

9. The seat cover is The fireproof sheet is completely covered so that the fireproof sheet is not exposed to the outside air. The battery module according to claim 7.

10. The cover slit is The width of the bus bar frame assembly is gradually narrowed along the direction toward the bus bar frame assembly. The battery module according to claim 7.

11. The spark delay protrusion and the spark delay recess are The side plates are alternately formed from the center to one end along the longitudinal direction of the side plates. The battery module according to claim 1 .

12. A battery pack comprising a battery module according to any one of claims 1 to 11.

13. 13. An energy storage device comprising the battery pack of claim 12.

14. A motor vehicle comprising the battery pack of claim 12.

Images