Battery module and battery pack including the same

Abstract

A battery module according to an embodiment of the present application includes a battery cell stack formed by vertically stacking a plurality of battery cells, a module cover for accommodating the battery cell stack, a busbar frame assembly covering an opening formed in one side of the module cover in a longitudinal direction, and a fireproof sheet assembly interposed between the busbar frame assembly and the battery cell stack and coupled to the busbar frame assembly.

Description

Technical Field

[0001] This disclosure relates to a battery module, a battery pack including the battery module, an energy storage system (ESS) including the battery pack, and a vehicle. More particularly, this disclosure relates to a battery module, a battery pack including the battery module, an energy storage system (ESS) including the battery pack, and a vehicle in which the battery module has a structure that allows gas to be discharged to the outside when the battery cell vents, preventing sparks containing high-temperature electrode active materials and metal particles from leaking to the outside of the battery module, and preventing oxygen from being introduced into the battery module to prevent fire in the battery module.

[0002] This application claims priority to Korean Patent Application No. 10-2021-0003508, filed in Korea on January 11, 2021, the disclosure of which is incorporated herein by reference. Background Technology

[0003] Battery packs used in energy storage systems (ESS) and / or electric vehicles can be manufactured as multiple battery modules, with high-power and high-capacity lithium secondary batteries incorporated into these modules. To meet the output power characteristics required by ESS and / or electric vehicles and to achieve high capacity, the number of lithium secondary batteries included in a single battery module can be increased, and the number of battery modules included in a battery pack can also be increased.

[0004] However, when a fire or explosion occurs in a battery pack containing such a large number of lithium secondary batteries, the damage is inevitably increased.

[0005] Fires in battery packs begin with an abnormal temperature rise and internal gas generation in the lithium-ion batteries within the battery module. When the temperature of the lithium-ion battery rises abnormally and internal gas is generated, causing the internal pressure of the lithium-ion battery to increase to a certain level or higher, venting occurs. As a result, high-temperature gas is ejected to the outside of the lithium-ion battery, along with high-temperature sparks containing electrode active materials and aluminum particles.

[0006] In this scenario, to prevent an increase in internal pressure within the battery module, the exhaust gases should be able to be rapidly vented to the outside of the battery module. However, when high-temperature sparks are vented to the outside of the battery module along with the exhaust gases, the exhaust gases, high-temperature sparks, and oxygen may come into contact and cause a fire.

[0007] Accordingly, there is a need to develop a battery module with a structure that can rapidly discharge exhaust gases to the outside of the battery module even when thermal runaway occurs due to anomalies such as short circuits in individual battery cells, and effectively prevent high-temperature sparks containing electrode active materials and aluminum particles from leaking to the outside.

[0008] Furthermore, when structures such as busbar frames, used to prevent short circuits between multiple lithium-ion batteries, are damaged due to continuous contact with sparks and high-temperature gases, oxygen may easily be introduced into the battery module from the outside, potentially causing a fire to spread into the battery module. Moreover, when the busbar frame is damaged, the electrode leads of adjacent lithium-ion batteries, which are kept separate by the busbar frame, may come into contact with each other, potentially escalating the accident.

[0009] Accordingly, there is a need to develop a battery module with a structure that prevents the free flow of external oxygen and prevents the accident from escalating due to short circuits between adjacent lithium secondary batteries, even when some structures are damaged by sparks and high-temperature gases. Summary of the Invention

[0010] Technical issues

[0011] This disclosure is designed to solve problems in related technologies, and therefore aims to provide a battery module having a structure that, in the event of an accident such as a fire, can quickly discharge exhaust gas, effectively prevent high-temperature sparks from leaking to the outside, and prevent outside air from being introduced into the battery module after the exhaust gas is discharged.

[0012] This disclosure also aims to provide a battery module having a structure that prevents external oxygen from being easily introduced into the battery module even when some structures are damaged due to sparks and high-temperature gases, and prevents short circuits between adjacent lithium secondary batteries.

[0013] However, the technical objectives to be addressed by this disclosure are not limited to those described above, and other objectives not mentioned herein will be clearly understood by those skilled in the art based on the following disclosure.

[0014] Technical solution

[0015] A battery module according to an embodiment of the present disclosure includes: a battery cell stack, in which a plurality of battery cells are vertically stacked; a module housing, in which the battery cell stack is housed; a busbar frame assembly, which covers an opening formed on one side of the module housing in the longitudinal direction of the module housing; and a fireproof sheet assembly, which is located between the busbar frame assembly and the battery cell stack and is connected to the busbar frame assembly.

[0016] The module housing may include: a substrate supporting the battery cell stack; and a pair of side plates covering two sides of the battery cell stack, wherein each of the pair of side plates includes a spark direction changing section formed by bending the longitudinal end of the side plate toward the battery cell stack.

[0017] The opening may be formed between a pair of spark direction changing portions respectively disposed on the pair of side plates, wherein the electrode leads of the battery cell are exposed to the outside of the module housing through the opening.

[0018] The busbar frame assembly may include: a busbar frame covering the opening and including a plurality of frame slits through which the electrode leads of the battery cell pass; and at least one busbar located on the outer surface of the busbar frame and connected to the electrode leads passing through the frame slits.

[0019] The fireproof sheet assembly may include: a fireproof sheet having a plurality of sheet slits through which the electrode leads of the battery cell pass; and 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.

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

[0021] The cover can completely cover the fireproof sheet, so that the fireproof sheet is not exposed to the outside air.

[0022] The module housing may further include a fastening frame that connects the pair of spark direction changing sections and has a hollow central section.

[0023] The fastening frame may be located between the busbar frame assembly and the fireproof sheet assembly, wherein the busbar frame assembly and the fireproof sheet assembly are tightly attached to the fastening frame and are connected to each other through the hollow central portion of the fastening frame.

[0024] Each of the plurality of cap slits may have a shape in which the width of each cap slit decreases toward the busbar frame assembly.

[0025] A battery pack according to an embodiment of the present disclosure includes a battery module according to an embodiment of the present disclosure.

[0026] An energy storage system (ESS) according to an embodiment of the present disclosure includes a battery pack according to an embodiment of the present disclosure.

[0027] A vehicle according to an embodiment of the present disclosure includes a battery pack according to an embodiment of the present disclosure.

[0028] Beneficial effects

[0029] According to one aspect of this disclosure, even when certain structures are damaged due to sparks and high-temperature gases caused by an accident, exhaust gases can be quickly released, effectively preventing high-temperature sparks from leaking to the outside, and preventing external air from being introduced into the battery module after the exhaust gases are released.

[0030] According to another aspect of this disclosure, even if some structures are damaged due to sparks and high-temperature gases, external oxygen can be prevented from being easily introduced into the battery module, and short circuits between adjacent lithium secondary batteries can be prevented. Attached Figure Description

[0031] The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the foregoing disclosure, serve to provide a further understanding of the technical features of the present disclosure. Therefore, the present disclosure is not to be construed as limited to the drawings.

[0032] Figure 1 This is a view showing a battery module according to an embodiment of the present disclosure.

[0033] Figure 2 This shows the busbar frame assembly and the fireproof sheet assembly from... Figure 1 A plan view showing the battery module in its removed state.

[0034] Figure 3 It is shown Figure 1 A partial cross-sectional view of the battery module shown.

[0035] Figure 4 This is a view showing the state in which the busbar frame assembly and fireproof sheet assembly according to this disclosure are connected to the module housing.

[0036] Figure 5 This is an exploded perspective view showing a portion of the module housing, the busbar frame assembly, and the fireproof sheet assembly according to this disclosure.

[0037] Figure 6This is a view showing the fire-retardant sheet assembly according to this disclosure. Detailed Implementation

[0038] Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Before the description, it should be understood that the terminology used in the specification and appended claims should not be construed as limited to its general and dictionary meaning, but rather interpreted based on its meaning and concept corresponding to the technical aspects of the present disclosure, on the basis of allowing the inventors to appropriately define the terminology for the best interpretation. Therefore, the description presented herein is merely a preferred example for illustrative purposes and is not intended to limit the scope of the present disclosure; thus, it should be understood that other equivalents and modifications can be made thereto without departing from the scope of the present disclosure.

[0039] refer to Figures 1 to 3 A battery module according to an embodiment of the present disclosure includes: a battery cell stack in which a plurality of battery cells 100 are stacked in a vertical direction (parallel to the Z-axis); a module housing 200 in which the battery cell stack is housed; a busbar frame assembly 300 covering an opening formed on one side of the module housing 200 in a longitudinal direction (parallel to the X-axis); and a fireproof sheet assembly 400 located between the busbar frame assembly 300 and the battery cell stack, and connected to the busbar frame assembly 300.

[0040] The battery cell 100 may be a pouch-type battery cell. In this case, the battery cell 100 includes: an electrode assembly (not shown); a pouch housing 110 in which the electrode assembly is housed; and a pair of electrode leads 120 connected to the electrode assembly and extending from the pouch housing 110. The pair of electrode leads 120 extend in opposite directions in the longitudinal direction (parallel to the X-axis) of the battery cell 100.

[0041] The module housing 200 includes: a substrate 210 supporting the battery cell stack; and a pair of side plates 220 covering two sides of the battery cell stack. Each of the pair of side plates 220 may include a spark direction changing section 200a, which is formed by bending an end of the side plate 220 in the longitudinal direction toward the battery cell stack.

[0042] The opening formed on one side of the module housing 200 in the longitudinal direction is formed between a pair of spark direction changing portions 200a respectively provided on the pair of side plates 220. The electrode leads 120 of the battery cell 100 can be exposed to the outside of the module housing 200 through the opening formed between the pair of spark direction changing portions 200a.

[0043] Because the battery module according to the embodiment of this disclosure includes a spark direction changing section 200a as described above, it prevents the high-temperature spark emitted during the venting of the battery cell 100 from being sprayed onto the outside of the module cover 200 along the longitudinal direction of the module cover 200. That is, during the venting of the battery cell 100, the high-temperature spark sprayed through the two sides of the battery cell 100 in the width direction (parallel to the Y-axis) of the battery cell stack moves toward one end and / or the other end in the longitudinal direction (parallel to the X-axis) of the battery module, and then switches its moving direction toward the battery cell stack (see...). Figure 2 (The direction of the arrow).

[0044] The module housing 200 may further include a fastening frame 230, which connects a pair of spark direction changing parts 200a and has a hollow central portion. The fastening frame 230 is located between the busbar frame assembly 300 and the fireproof sheet assembly 400. When the fastening frame 230 is provided, the busbar frame assembly 300 and the fireproof sheet assembly 400 can be tightly attached to the fastening frame 230 and can be fastened to each other through the hollow central portion of the fastening frame 230.

[0045] Although not shown, the opening of the module cover 200 described in this disclosure may be formed on both sides in the longitudinal direction of the module cover 200. In this case, a pair of spark direction changing parts 200a may also be provided on one side and the other side in the longitudinal direction of the module cover 200.

[0046] refer to Figures 1 to 5 The busbar frame assembly 300 includes a busbar frame 310 and at least one busbar 320. A pair of busbar frame assemblies 300 may be provided, and in this case, the pair of busbar frame assemblies 300 respectively cover an opening formed on one side and an opening formed on the other side in the longitudinal direction (parallel to the X-axis) of the module cover 200.

[0047] The busbar frame 310 covers the opening of the module housing 200 and includes a plurality of frame slits 310b through which the electrode leads 120 of the battery cell 100 pass. The busbar frame 310 may further include at least one frame protrusion 310a for connection with the fireproof sheet assembly 400.

[0048] The busbar 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 tightly attached to the module housing 200. When the module housing 200 includes the fastening frame 230 as described above, the busbar frame 310 is tightly attached to the spark direction changing part 200a and the fastening frame 230.

[0049] The busbar 320 is located on the outer surface of the busbar frame 310 and is connected to the electrode lead 120 passing through the frame slit 310b to electrically connect the plurality of battery cells 100. The busbar 320 may include a busbar slit 320b through which the electrode lead 120 passes. In this case, the busbar slit 320b and the frame slit 310b may be formed at corresponding positions.

[0050] refer to Figures 1 to 6 The fireproof sheet assembly 400 includes a fireproof sheet 410 and a cover 420. The same number of fireproof sheet assemblies 400 as the busbar frame assembly 300 can be provided.

[0051] The fireproof sheet 410 may be a sheet formed of mica material that can withstand high-temperature exhaust gases and sparks. The fireproof sheet 410 includes a plurality of sheet slits 410b, through which electrode leads 120 pass.

[0052] Even if the busbar frame 310, formed of resin material, is damaged due to high-temperature exhaust gases and sparks, the fireproof sheet 410 can maintain its structure, thus maintaining the positions of the plurality of electrode leads 120 respectively inserted into the plurality of slits 410b. Furthermore, the fireproof sheet 410 allows high-temperature exhaust gases to be discharged to the outside through the gap located between the slits 410b and the electrode leads 120, and minimizes the outward ejection of high-temperature sparks containing active materials and aluminum particles. Moreover, even if the busbar frame 310, formed of resin material, is damaged, the fireproof sheet 410 can prevent oxygen from being easily introduced into the battery module from the outside.

[0053] Accordingly, even in the event of an accident in the battery module, the fireproof sheet 410 can minimize the fire risk around the busbar frame 310, and even if a fire occurs around the busbar frame 310, the fireproof sheet 410 can delay the spread of the fire to the battery module. Furthermore, the fireproof sheet 410 can prevent the spread of an accident caused by a short circuit between the battery cells 100 due to damage to the busbar frame 310.

[0054] The cover 420 completely surrounds the fireproof sheet 410, preventing the fireproof sheet 410 from being exposed to the outside. This is because the fireproof sheet 410, formed of mica material, is hygroscopic. Therefore, when the fireproof sheet 410 is exposed to the outside air of the cover 420, it may absorb moisture, thereby deteriorating its thermal insulation performance.

[0055] The cover 420 may be a resin injection molded product, and in this case, the fireproof sheet 410 may be positioned within the cover 420 by insert injection molding. The cover 420 includes a plurality of cover slits 420b through which the electrode leads 120 pass. The cover slits 420b have a shape in which their width decreases toward the busbar frame assembly 300.

[0056] This is to quickly close the cap slit 420b when the cap 420 formed from the resin injection molded product melts due to high-temperature exhaust gases and sparks, and to prevent air from flowing in from the outside of the battery module. In this way, when the inflow of external air is quickly blocked, oxygen can be prevented from being supplied to the battery module, thus preventing the fire from spreading into the battery module.

[0057] The cover slit 420b, the sheet slit 410b, and the frame slit 310b are formed at corresponding positions.

[0058] When the busbar frame 310 includes a frame protrusion 310a, the fireproof sheet 410 and the sheet cover 420 respectively include at least one sheet hole 410a and a cover hole 420a, the at least one sheet hole 410a and the cover hole 420a being formed to have a position and shape corresponding to the frame protrusion 310a, so as to be fastened to the busbar frame 310.

[0059] A battery pack according to embodiments of the present disclosure includes battery modules according to embodiments of the present disclosure. The battery pack may include multiple battery modules. An energy storage system (ESS) according to embodiments of the present disclosure includes a battery pack according to embodiments of the present disclosure. A vehicle according to embodiments of the present disclosure includes a battery pack according to embodiments of the present disclosure. The vehicle includes an electric vehicle.

[0060] While embodiments of this disclosure have been shown and described above, this disclosure is not limited to the specific embodiments described above. Various modified embodiments can be made by those skilled in the art without departing from the scope of this disclosure as claimed in the claims.

Claims

1. A battery module, comprising: A battery cell stack, in which multiple battery cells are stacked vertically; The module housing contains the stack of battery cells. A busbar frame assembly that covers an opening formed on one side in the longitudinal direction of the module housing; and A fire-resistant sheet assembly is located between the busbar frame assembly and the battery cell stack, and is connected to the busbar frame assembly. The fireproof sheet assembly includes: A fireproof sheet, comprising a plurality of slits, through which the electrode leads of the battery cell pass; and A cover, comprising a plurality of cover slits, through which the electrode leads of the battery cell pass, and the cover covering the fireproof sheet. The fireproof sheet is a mica sheet.

2. The battery module according to claim 1, wherein, The module housing includes: A substrate, the substrate supporting the battery cell stack; and A pair of side plates covering two sides of the battery cell stack. Each of the pair of side plates includes a spark direction changing section, which is formed by bending the longitudinal end of the side plate toward the battery cell stack.

3. The battery module according to claim 2, wherein, The opening is formed between a pair of spark direction changing portions respectively disposed on the pair of side plates. The electrode leads of the battery cell are exposed to the outside of the module casing through the opening.

4. The battery module according to claim 1, wherein, The busbar frame component includes: A busbar frame, the busbar frame covering the opening and including a plurality of frame slits through which the electrode leads of the battery cell pass; and At least one busbar is located on the outer surface of the busbar frame and is connected to the electrode lead passing through the slit of the frame.

5. The battery module according to claim 1, wherein, The cover completely covers the mica sheet, so that the mica sheet is not exposed to the outside air.

6. The battery module according to claim 3, wherein, The module housing further includes a fastening frame that connects the pair of spark direction changing parts and has a hollow central portion.

7. The battery module according to claim 6, wherein, The fastening frame is located between the busbar frame assembly and the fireproof sheet assembly. The busbar frame assembly and the fireproof sheet assembly are tightly attached to the fastening frame and connected to each other through the hollow central portion of the fastening frame.

8. The battery module according to claim 1, wherein, Each of the plurality of cap slits has a shape in which the width of the cap slit decreases toward the busbar frame assembly.

9. A battery pack comprising a battery module according to any one of claims 1 to 8.

10. An energy storage system (ESS) comprising the battery pack according to claim 9.

11. A vehicle comprising the battery pack according to claim 9.

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