Battery module and battery pack containing it

Abstract

The battery module according to the present invention includes a laminate consisting of stacked battery cells, a module case having gas vent holes in the bottom plate and housing the cell laminate, and a venting guide member including a main body portion having the property of warping in shape due to heat and a needle portion connected to the main body portion, wherein the venting guide member may be positioned on the bottom plate such that when the main body portion rises above a predetermined temperature, the main body portion warps, causing the needle portion to contact the battery cells.

Description

Technical Field

[0005] ,

[0004] , , ,

[0006]

[0001] The present invention relates to a battery module and a battery pack including the same, and more particularly, to a battery module with improved safety against thermal events and the like, and a battery pack including the same.

[0002] This application claims priority based on Korean Patent Application No. 10-2024-0029489 filed on February 29, 2024, and all the contents disclosed in the specification and drawings of the application are incorporated into this application.

Background Art

[0003] As the development of technologies and the demand for various mobile devices, electric vehicles, energy storage systems (ESS), etc. increase, the interest and demand for secondary batteries as an energy source are rapidly increasing. Conventionally, nickel-cadmium batteries or nickel-metal hydride batteries were often used as secondary batteries, but this year, lithium secondary batteries with almost no memory effect, free charging and discharging, a very low self-discharge rate, and high energy density are often used compared to nickel-based secondary batteries.

[0004] Such lithium secondary batteries mainly use lithium-based oxides and carbon materials as the positive electrode active material and the negative electrode active material, respectively. A lithium secondary battery includes an electrode assembly in which a positive electrode plate and a negative electrode plate each coated with such a positive electrode active material and a negative electrode active material are arranged with a separator interposed therebetween, and an exterior material that seals and houses the electrode assembly together with an electrolytic solution, that is, a battery case.

[0005] Generally, lithium secondary batteries are classified into can-type secondary batteries in which the electrode assembly is built into a metal can, and pouch-type secondary batteries in which the electrode assembly is built into a pouch of an aluminum laminate sheet, depending on the shape of the exterior material.

[0006] Lithium-ion batteries commonly used today have an operating voltage of approximately 2.5V to 4.5V per unit. Therefore, in electric vehicles and power storage devices that require large capacity and high output, battery modules or battery packs are constructed by connecting multiple lithium-ion batteries in series and / or parallel, and these are used as the energy source. In particular, battery modules and battery packs contain a large number of lithium-ion batteries to meet the output and capacity requirements of electric vehicles.

[0007] On the other hand, such battery modules or battery packs may experience a thermal event, such as a gas or flame, which causes heat to accumulate internally and rapidly propagate between battery cells (thermal runaway). As a result, the battery cells may explode in a chain reaction, posing a serious risk to the user's life and property.

[0008] Therefore, when a thermal event occurs, it is necessary to actively dissipate the heat and pressure from inside the battery module to minimize damage before the heat and pressure inside the battery module rapidly increase, causing the battery cells to explode in a chain reaction or the battery module to collapse. [Overview of the project] [Problems that the invention aims to solve]

[0009] The present invention was devised to solve the aforementioned technical problems and aims to provide a battery module that can effectively disperse or eliminate heat and pressure when a thermal event occurs.

[0010] However, the technical problems that this invention aims to solve are not limited to those described above, and other problems not mentioned will be clearly understood by those skilled in the art from the description of the invention below. [Means for solving the problem]

[0011] According to one aspect of the present invention, a battery module can be provided that includes a cell stack consisting of stacked battery cells, a module case having gas vent holes in its bottom plate and housing the cell stack, and a venting guide member including a main body having the property of warping in shape due to heat, and a needle portion connected to the main body, wherein the venting guide member is positioned on the bottom plate such that when the main body rises above a predetermined temperature, the main body warps, causing the needle portion to contact the battery cells.

[0012] The main body may include a first metal part and a second metal part that are stacked on top of each other and are made of dissimilar metals with different coefficients of thermal expansion.

[0013] The second metal portion has a higher coefficient of thermal expansion than the first metal portion, and the venting guide member may be positioned on the bottom plate of the module case such that the second metal portion faces the bottom plate of the module case.

[0014] The main body may include a needle insertion hole into which the needle portion is inserted, and an elastic member disposed in the needle insertion hole and coupled to the needle portion.

[0015] The bottom plate of the module case may include a needle blocking portion configured to compress the elastic member and block the front of the needle portion so that the needle portion inserted into the needle insertion hole does not pop out.

[0016] The main body portion includes a rotating shaft portion formed to protrude from the side, and the bottom plate of the module case may be provided with a shaft mounting portion that engages with the rotating shaft portion.

[0017] The bottom plate of the module case includes a groove that is recessed to correspond to the main body, and the venting guide member can be inserted into the groove.

[0018] The needle portion may be a plurality of needle portions, and the spacing between the needle portions may be configured to correspond to the thickness of the battery cell.

[0019] The module case may include an upper plate that covers the upper part of the cell stack, a lower plate that covers the lower part of the cell stack and forms the bottom plate, a pair of side plates that cover both sides of the cell stack, and a pair of end covers that cover the front and rear of the cell stack, respectively.

[0020] The battery cell is a pouch-type battery cell, and the gas vent holes are provided at predetermined intervals along the width direction of the lower plate, and the gas vent holes may be provided at positions corresponding to the cell terraces formed by heat welding of the pouch sheet in the pouch-type battery cell.

[0021] The venting guide members may be arranged alternately with the gas vent holes along the width direction of the lower plate on the lower plate.

[0022] The invention further includes a busbar electrically connected to electrode leads provided in the battery cell, and a busbar frame that supports the busbar, has lead slots through which the electrode leads pass, and is attached to the front or rear of the cell stack, wherein the busbar includes a first busbar and a second busbar arranged to overlap the electrode leads, and the electrode leads can be crimped and fixed between the first busbar and the second busbar.

[0023] The battery cells are pouch-type battery cells, each with a wide surface upright and stacked in one direction, and the cell stack includes a plurality of barrier plates sandwiched between the battery cells at predetermined intervals along the one direction to restrict the movement of heat or gas between the battery cells, and each of the plurality of barrier plates may be joined by being sandwiched at the ends of the busbar frame such that the battery cells and the gas vent holes are partitioned into a predetermined number of units.

[0024] In addition, according to another aspect of the present invention, a battery pack including the above-described battery module may be provided.

Effects of the Invention

[0025] According to the present invention, a battery module capable of effectively dispersing or eliminating heat and pressure at the time of occurrence of a thermal event can be provided.

[0026] In particular, according to the venting guiding member of the present invention, a hole is formed in a trigger battery cell having a thermal abnormality sign, and high-temperature gas, particles, etc. ejected from the trigger battery cell are discharged to the outside of the module case from a gas vent hole formed in the bottom plate of the module case.

[0027] In addition, the present invention exhibits various other effects, which will be described in each implementation configuration, or the description will be omitted for effects that can be easily inferred by those skilled in the art.

Brief Description of the Drawings

[0028] [Figure 1] It is a schematic perspective view of a battery module according to an embodiment of the present invention.

[0029] [Figure 2] It is an exploded perspective view of the battery module of FIG. 1.

[0030] [Figure 3] It is a perspective view of the cell laminate of FIG. 2.

[0031] [Figure 4] It is a view showing the lower plate of the module case of FIG. 2.

[0032] [Figure 5] It is a view showing a venting guiding member according to an embodiment of the present invention, showing a main body portion and a needle portion partially inserted into the main body portion.

[0033] [Figure 6] This figure shows a venting guide member according to one embodiment of the present invention, comprising a main body and a needle portion protruding from the main body.

[0034] [Figure 7] This is a schematic cross-sectional view of the venting guide member along line A-A' in Figure 6.

[0035] [Figure 8] This is a magnified view of a portion of the lower plate according to one embodiment of the present invention.

[0036] [Figure 9] This figure shows the venting guide member attached to the lower plate in Figure 8.

[0037] [Figure 10] This figure shows the state of a venting guide member before operation according to one embodiment of the present invention.

[0038] [Figure 11] This figure shows the operating state of a venting guide member according to one embodiment of the present invention.

[0039] [Figure 12] This figure illustrates an example of assembling a cell stack and a busbar frame according to one embodiment of the present invention.

[0040] [Figure 13] Figure 12 shows a busbar frame in which the frame cover and the crimped busbar are connected.

[0041] [Figure 14] This is a schematic cross-sectional view of an interconnected cell stack and busbar frame according to one embodiment of the present invention.

[0042] [Figure 15] This diagram schematically shows an automobile including a battery pack according to one embodiment of the present invention. [Modes for carrying out the invention]

[0043] Preferred embodiments of the present invention will now be described in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and in the claims should not be interpreted in a manner limited to their ordinary or dictionary meanings, but rather in a manner consistent with the technical idea of ​​the present invention, in accordance with the principle that the inventor himself may appropriately define the concepts of terms in order to best describe the invention. Accordingly, it should be understood that the embodiments described herein and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent the entirety of the technical idea of ​​the present invention, and that there may be a variety of equivalents and modifications that can be substituted therein at the time of this application.

[0044] The size of each component or specific part of a component in the drawings may be exaggerated, omitted, or shown schematically for the sake of clarity and ease of explanation. Therefore, the size of each component may not fully reflect its actual size. Specific descriptions of known functions or configurations related to the present invention will be omitted if they are deemed to unnecessarily obscure the gist of the invention.

[0045] Figure 1 is a schematic perspective view of a battery module according to one embodiment of the present invention, and Figure 2 is an exploded perspective view of the battery module of Figure 1. Figure 3 is a perspective view of the cell stack of Figure 2, and Figure 4 shows the lower plate of the module case of Figure 2.

[0046] Referring to Figures 1 to 4, a battery module 10 according to one embodiment of the present invention includes a cell stack 100 consisting of stacked battery cells 110, a module case 200 having a gas vent hole 201 in its bottom plate and housing the cell stack 100, and a venting guide member 300 that operates when the temperature rises above a certain level.

[0047] As shown in Figures 2 and 3, the cell stack 100 can be described as an assembly of battery cells 110 stacked vertically in the horizontal direction (X direction). In this embodiment, the battery cell 110 is a pouch-type battery cell 110. The pouch-type battery cell 110 may include an electrode assembly, an electrolyte, a pouch case that seals and houses the electrode assembly and the electrolyte, and electrode leads 111.

[0048] The pouch case is composed of two pouch sheets, at least one of which may have a groove for housing an electrode assembly. The electrode assembly and electrolyte are placed in the electrode assembly housing groove, covered with the remaining pouch sheet, and then the edges of the two pouch sheets are heat-sealed. In such a pouch-type battery cell 110, the portion of the pouch sheet sealed by heat-sealing is called the sealed portion. One end of the electrode lead 111 is connected to the electrode assembly inside the pouch case, and the other end protrudes outside the pouch case, with a portion between the one end and the other end fixed inside the sealed portion when the pouch sheet is heat-sealed. The portion of the electrode lead 111 exposed outside the pouch case can function as an electrode terminal of the pouch-type battery cell 110.

[0049] For reference, a pouch-type battery cell 110 in which the electrode assembly is packaged with two pouch sheets has four sealing parts. Here, the four sealing parts refer to the front sealing part and rear sealing part in which the electrode leads 111 protrude, and two lateral sealing parts extending in the longitudinal direction of the electrode assembly. On the other hand, a pouch-type battery cell 110 in which the electrode assembly is packaged by folding a single pouch sheet has three sealing parts. Here, the three sealing parts refer to the front sealing part and rear sealing part in which the electrode leads 111 protrude, and one lateral sealing part. In particular, in the pouch-type battery cell 110, the front sealing part and the rear sealing part are referred to as cell terraces 112.

[0050] The cell stack 100 may further include barrier plates 120 placed between the battery cells 110. The barrier plates 120 may be made of a material with excellent heat insulation and fire resistance and may be provided in the form of a plate. Such barrier plates 120 prevent heat transfer between the battery cells 110 and absorb pressure when the battery cells 110 swell.

[0051] Referring to Figures 1 and 2, the module case 200 may consist of a case body and a pair of end covers 250 and 260.

[0052] The case body may include an upper plate 210 that covers the upper part of the cell stack 100, a lower plate 220 that covers the lower part of the cell stack 100, and a pair of side plates 230 and 240 that cover both sides of the cell stack 100, respectively.

[0053] The lower plate 220 and the pair of side plates 230, 240 can be formed integrally. The integral provision of the lower plate 220 and the pair of side plates 230, 240 can be referred to as a U-frame. The U-frame and the upper plate 210 can be joined by methods such as bolting, welding, or bonding. On the other hand, unlike this embodiment, the upper plate 210, the lower plate 220, and the pair of side plates 230, 240 can be formed integrally as a rectangular tubular shape. The end covers 250, 260 can be joined to the open front and rear of the case body.

[0054] In this embodiment, the upper plate 210 may be provided with terminal pass-through holes for drawing the terminal busbars of the battery module 10 upward. The terminal busbars include a positive terminal busbar 410a and a negative terminal busbar 410b. However, unlike in this embodiment, the terminal busbars may be redesigned to pass through, for example, the end covers 250 and 260 and extend forward.

[0055] The bottom plate of the module case 200 may be formed by the lower plate 220. Thermal resin TR is applied to the upper surface of the lower plate 220, and the cell laminate 100 may be mounted on the thermal resin TR. In this case, the lower edges of the battery cells 110 may come into contact with the thermal resin TR. In this case, the thermal conductivity and fixation between the battery cells 110 and the lower plate 220 are increased. In particular, during charging and discharging, the heat generated in each battery cell 110 can be effectively transferred to the lower plate 220 via the thermal resin TR for heat dissipation. Although not shown, if a heat sink (not shown) is further provided on the lower surface of the lower plate 220, the heat from the battery cells 110 can be absorbed more quickly.

[0056] In a pouch-type battery cell 110, for example, a large amount of gas may be generated as a side reaction during overcharging, causing a swelling phenomenon. If this swelling progresses further, the bonding strength of the heat-welded sealing portion weakens, and that portion may rupture, releasing gas. In this case, the cell terrace 112 of the sealing portion of the pouch-type battery cell 110 generates relatively more heat than other parts due to the presence of the electrode leads 111, resulting in lower bonding strength. Consequently, when the internal pressure of the pouch-type battery cell 110 rises, the cell terrace 112 is the most likely area to be damaged.

[0057] Therefore, in the battery module 10 according to one embodiment of the present invention, gas vent holes 201 are provided at both ends of the lower plate 220 that correspond to the cell terrace 112 vertically, so that gases and other substances ejected when the cell terrace 112 is damaged are immediately discharged to the outside of the battery module 10.

[0058] Specifically, the gas vent holes 201 according to this embodiment may be provided at predetermined intervals along the width direction (X direction) of the lower plate 220, as shown in Figure 2 or Figure 4. Furthermore, when the cell stack 100 is housed in the module case 200, the gas vent holes 201 may be provided at positions corresponding to the cell terraces 112 of the pouch-type battery cell 110 in the vertical direction. In this embodiment, the pouch-type battery cell 110 has cell terraces 112 at the front and rear, respectively. The gas vent holes 201 may be provided at the front and rear of the lower plate 220, respectively, to correspond to the cell terraces 112 of such a pouch-type battery cell 110.

[0059] In other words, a plurality of gas vent holes 201 may be provided along the same direction as the stacking direction of the pouch-type battery cells 110. The plurality of gas vent holes 201 may be provided on the lower plate 220 at positions adjacent to the front sealing portion and the rear sealing portion of the pouch-type battery cells 110.

[0060] The gas vent holes 201 can, under normal conditions, prevent a pressure difference from occurring between the inside and outside of the module case 200. Furthermore, when a thermal event occurs, the gas vent holes 201 prevent excessive heat buildup inside the battery module 10 by venting high-temperature gases ejected from the battery cells 110 to the outside, thereby preventing a rapid increase in the internal pressure of the battery module 10.

[0061] In particular, according to the implementation configuration shown in Figure 2 or Figure 4, when a high-temperature gas is ejected from the trigger battery cell 110 where a thermal event has occurred, the high-temperature gas does not diffuse into the module case 200 but is instead guided downwards through the gas vent hole 201 and discharged. In this case, thermal damage to the trigger battery cell 110 and other battery cells 110 adjacent to it can be significantly prevented. In addition, a large amount of gas is discharged more quickly to the outside of the battery module 10, preventing a rapid increase in the internal pressure of the battery module 10.

[0062] On the other hand, the battery module 10 according to the present invention includes not only the gas vent holes 201, but also a venting guide member 300 as a means for creating holes in the battery cells 110 and releasing gas from the battery cells 110 to relieve internal pressure when a thermal event occurs.

[0063] As shown in Figures 5 and 6, the venting guide member 300 may include a main body portion 310 and a needle portion 320 connected to the main body portion 310.

[0064] The main body portion 310 may be provided such that it has the property of warping in shape due to heat. In this embodiment, the main body portion 310 may include a first metal portion 311 and a second metal portion 312 made of dissimilar metals with different coefficients of thermal expansion, which are stacked on top of each other to form a layered structure. The first metal portion 311 and the second metal portion 312 may be joined together by mechanical fastening such as welding or riveting.

[0065] For example, the first metal part 311 may be made of steel, and the second metal part 312 may be made of copper or brass. Copper or brass is a metal with a higher coefficient of thermal expansion than steel. In other words, the second metal part 312 is a metal with a higher coefficient of thermal expansion than the first metal part 311. In this way, the main body 310 is made of dissimilar metals with different coefficients of thermal expansion, so when heated, the second metal part 312 expands more than the first metal part 311. Furthermore, since the first metal part 311 and the second metal part 312 are firmly bonded to each other, the main body 310 may bend toward the first metal part 311.

[0066] In this embodiment, the main body portion 310 may further include a needle insertion hole 313 inside it, and an elastic member 314 disposed inside the needle insertion hole 313, with one end connected to the inside of the needle insertion hole 313 and the other end connected to the needle portion 320.

[0067] For example, as shown in Figure 7, the needle insertion hole 313 can be defined as a space or passage provided inside the main body 310 so that the needle portion 320 is inserted into the main body 310. The elastic member 314 can be defined as a means of providing force to cause the needle portion 320 to elastically spring out from the inside to the outside of the main body 310. For example, a spring can be used as the elastic member 314.

[0068] The main body portion 310 may further include a rotating shaft portion 315 formed to protrude from its side. The rotating shaft portion 315 is a portion that fits into a shaft mounting portion 225 provided on the bottom plate of the module case 200, which will be described later. The venting guide member 300 may be provided on the bottom plate of the module case 200 so as to be rotatable about the rotating shaft portion 315.

[0069] The needle portion 320 is a means for making holes in the battery cell 110, and its end may be provided in the form of a nail or needle. There may be multiple needle portions 320, and the spacing between the needle portions 320 may be configured to correspond to the thickness of the battery cell 110.

[0070] As shown in Figures 5 and 6, the needle portion 320 may include a first needle portion 321 and a second needle portion 322 that are connected to the main body portion 310 in a manner that protrudes from it and are separated by approximately the thickness of the battery cell 110. As will be described later, two adjacent, different battery cells 110 may come into contact with the first needle portion 321 and the second needle portion 322 and be perforated.

[0071] In this embodiment, the venting guide member 300 may be positioned on the bottom plate of the module case 200 such that the second metal portion 312 faces the bottom plate of the module case 200. The venting guide member 300 may be positioned alternately with the gas vent holes 201 on the bottom plate of the module case 200, i.e., along the width direction of the lower plate 220. The venting guide member 300 may also be positioned adjacent to the front sealing portion or the rear sealing portion of the battery cell 110.

[0072] When such a venting guide member 300 receives heat from the lower plate 220 or when its temperature rises above a certain level due to the influence of high-temperature particles or flames, the main body portion 310 bends beyond a predetermined angle relative to the bottom plate, causing it to face the battery cell 110. At this time, the needle portion 320 may come into contact with the battery cell 110, potentially forming a hole in the battery cell 110.

[0073] In the following, with reference to Figures 8 to 11, an example of the installation and operation of the venting guide member 300 according to one embodiment of the present invention will be described in more detail. In the following, the bottom plate of the module case 200 refers to the lower plate 220 mentioned above.

[0074] First, referring to Figure 8, the bottom plate of the module case 200 according to one embodiment of the present invention may further include a groove 221, a needle blocking portion 223, and a shaft mounting portion 225.

[0075] The groove 221 may be provided in a recessed form corresponding to the main body 310 of the venting guide member 300. The groove 221 may be provided between each of the gas vent holes 201. The venting guide member 300 can be inserted into such groove 221. In this case, the venting guide member 300 is inserted into the groove 221 such that the second metal part 312 of the first metal part 311 and the second metal part 312 is positioned lower on the main body 310. By configuring the groove 221 in the bottom plate of the module case 200 in this way, it is easier to position the venting guide member 300 in the correct position and to suppress the movement of the venting guide member 300.

[0076] The needle blocking portion 223 (see Figure 6) serves to block the front of the needle portion 320 so that the needle portion 320, which has been pulled into the needle insertion hole 313 of the main body portion 310, does not protrude from the needle insertion hole 313.

[0077] As shown in Figure 9, the venting guide member 300 may be positioned in the groove 221 with the needle portion 320 inserted inside the main body portion 310. The needle blocking portion 223 is provided at the end of the groove 221 or slightly away from the groove 221 toward the battery cell 110 side, and may be formed higher than the needle portion 320 of the venting guide member 300 mounted in the groove 221. The bottom plate of the module case 200 may have a step. That is, the bottom plate of the module case 200 has a first layer S1 on which the venting guide member 300 is arranged and a second layer S2 on which the battery cell 110 is arranged, and the second layer S2 may be set higher than the first layer S1. In this case, the stepped surface between the first layer S1 and the second layer S2 may function as the needle blocking portion 223.

[0078] The needle blocking portion 223 may be made of a curved surface. When the main body portion 310 bends upward due to heat from the groove portion 221, the needle portion 320 can be guided along the curved surface of the needle blocking portion 223. In this case, the needle portion 320 can pop out from the main body portion 310 toward the battery cell 110 more smoothly than when the needle blocking portion 223 is flat. Specifically, when the needle blocking portion 223 is flat, the frictional force between the end of the needle portion 320 and the needle blocking portion 223 increases, which may hinder the main body portion 310 from bending upward, and the end of the needle portion 320 may be damaged. However, with a curved needle blocking portion 223, the frictional force with the end of the needle portion 320 is relatively small, so this problem does not occur.

[0079] As shown in Figure 8, the shaft mounting portion 225 may be provided with a fitting hole into which the rotating shaft portion 315 of the venting guide member 300 fits, and with a structure that protrudes upward from the side surface of the groove portion 221. On the other hand, unlike this embodiment, if the depth of the groove portion 221 is deep enough to fully insert the venting guide member 300, the shaft mounting portion 225 may be provided on the side surface of the groove portion 221.

[0080] The rotating shaft portion 315 of the venting guide member 300 may be provided on each side of the main body portion 310. Two shaft mounting portions 225 may also be provided to correspond to the two rotating shaft portions 315 of the venting guide member 300. As shown in Figure 9, the venting guide member 300 may be attached to the groove portion 221 with the two rotating shaft portions 315 fitted into the two shaft mounting portions 225. In this case, even if an external force is applied, the venting guide member 300 can be stably disposed in the groove portion 221 without coming loose. Furthermore, when the main body portion 310 warps due to heat, the venting guide member 300 can be rotated around the rotating shaft portion 315 as an axis.

[0081] As shown in Figure 10, a venting guide member 300 may be provided on the bottom plate of the module case 200 having the above configuration. In this embodiment, if a thermal event such as ignition occurs inside the battery module 10, as shown in Figure 11, the venting guide member 300 will activate and create a hole in the battery cell 110, thereby guiding and discharging high-temperature gas from the battery cell 110. For example, as mentioned above, when the main body 310 is subjected to heat, the thermal expansion coefficient of the second metal part 312 is greater than that of the first metal part 311, causing the main body 310 to bend upward. At this time, the needle part 320, which was inserted inside the main body 310, will pop out toward the body 113 of the battery cell 110, thereby forming a hole in the battery cell 110. The venting guide member 300 according to this embodiment is configured to create a hole in the body 113 or sealing portion of the nearby battery cell 110, which allows high-temperature gases and other substances to be guided and discharged more smoothly and quickly to the outside of the battery module 10.

[0082] Figure 12 is a diagram illustrating an example of assembly of a cell laminate and a busbar frame according to one embodiment of the present invention, and Figure 13 is a diagram showing the busbar frame in Figure 12, in which the frame cover and crimp busbars are connected. Figure 14 is a schematic cross-sectional view of the cell laminate and busbar frame assembled together according to one embodiment of the present invention.

[0083] Referring to Figures 2 and 12 to 14, a battery module 10 according to one embodiment of the present invention may further include a plurality of busbars electrically connected to electrode leads 111 provided on a battery cell 110, a busbar frame 400, a frame cover 500, and a contact cover 700.

[0084] The busbar may be formed from an electrically conductive metal such as copper or aluminum, and may be provided in the form of a rod.

[0085] The busbar frame 400 may be provided in a plate-like form that supports the busbar and covers the front and rear portions of the cell stack 100, respectively. Here, the busbar frame 400 may be formed from an electrically insulating material such as plastic. The busbar frame 400 may also be provided with lead slots 420 through which the electrode leads 111 pass. The electrode leads 111 of the battery cell 110 may pass through the lead slots 420 and be attached to the busbar 410 in a predetermined pattern.

[0086] In particular, the battery module 10 of this embodiment is configured such that the electrode leads 111 are attached to the busbar by crimping them to the busbar without welding them to the busbar. Therefore, the assembly time of the battery module 10 is shortened and the assembly process becomes easier.

[0087] Specifically, a busbar according to one embodiment of the present invention includes a first busbar 410 and a second busbar 600. Referring to Figures 12 and 13, the first busbar 410 and the second busbar 600 may be arranged superimposed on each other with the electrode lead 111 in between. The electrode lead 111 may be crimped and fixed between the first busbar 410 and the second busbar 600. In this case, the first busbar 410 and the second busbar 600 may be firmly connected by a fastening member 800 such as a bolt.

[0088] The frame cover 500 is made of a material with low thermal conductivity and excellent heat resistance, for example, silicone, aerogel, or mica material, and is provided in the form of a pad, and can be bonded to the busbar frame 400 facing it, as shown in Figure 13. The frame cover 500 may include a plurality of cover plates 510. Each cover plate 510 may be provided so as to correspond to a partitioned surface of the busbar frame 400 that is partitioned by a partition wall 430 protruding from the busbar frame 400 and the end portion 121 of a barrier plate 120, which will be described later. Here, the partition wall 430 and the end portion 121 of the barrier plate 120 serve to prevent short circuits between the electrode leads 111.

[0089] When the frame cover 500 is attached to the busbar frame 400, the lead slots 420 of the busbar frame 400 may be covered. With this configuration, in the event of a thermal event, hot gases or flames will not leak from the lead slots 420 to the front or rear of the cell stack 100.

[0090] The electrode lead 111 is bent according to a predetermined pattern and positioned on the front of the corresponding first busbar 410, and then the frame cover 500 can be attached to the busbar frame 400, where the frame cover 500 has busbar insertion holes H. The second busbar 600 may be configured to connect with the first busbar 410 by sandwiching the electrode lead 111 through the busbar insertion holes H.

[0091] The contact cover 700 is a component that brings the frame cover 500 into close contact with the busbar frame 400 and brings the second busbar 600 into close contact with the electrode lead 111 and the first busbar 410.

[0092] The contact cover 700 may be composed of a plurality of contact plates 710, as shown in Figure 13. The number of contact plates 710 may correspond to the number of busbars. Each contact plate 710 may be coupled to the corresponding busbar so as to be fixed to each other by fastening members 800. The contact plates 710 may also be installed between the end portion 121 of the barrier plate 120 that penetrates the busbar frame 400 and the partition wall 430 that protrudes from the busbar frame 400. The contact plates 710 may be made of a material that has high mechanical rigidity and flame retardant properties. For example, the contact plates 710 may be made of a rigid material with a high melting point, such as SUS, that has been insulated, or a rigid material that has fire-resistant and insulating properties.

[0093] As described above, a cell stack 100 according to one embodiment of the present invention may include a plurality of barrier plates 120 sandwiched between battery cells 110 at predetermined intervals along one direction, thereby restricting the movement of heat or gas between the battery cells 110.

[0094] Each of the plurality of barrier plates 120 can be joined by having its end portion 121 sandwiched between the busbar frame 400, as shown in Figures 13 and 14, such that the battery cells 110 and the gas vent holes 201 are partitioned into predetermined units.

[0095] The barrier plate 120 may be provided in the form of a compressible pad made of a material with excellent heat resistance and / or fire resistance, such as silicone, aerogel, or mica.

[0096] As shown in Figure 14, such a barrier plate 120 can perform a thermal barrier function that blocks hot air, such as flames generated in a ignited battery cell 110, from advancing in the stacking direction of the battery cells 110. Therefore, heat transfer to adjacent battery cells 110 can be minimized. The barrier plate 120 can block not only heat, but also high-temperature gases, flames, and ejecta generated in the battery cells 110. Thus, the blocking member can partition or separate the battery cells 110 to prevent the transfer of flames and other substances between them.

[0097] On the other hand, the battery pack according to the present invention may include one or more of the aforementioned battery modules 10. The battery pack according to the present invention may further include a master BMS (Battery Management System) for integrated control of the charging and discharging of one or more battery modules 10, a current sensor, a fuse, and a pack case for housing the aforementioned components.

[0098] Referring to Figure 15, the battery pack 2 according to the present invention can be used as a driving energy source for an electric vehicle. That is, the battery pack 2 can be used as an electrical energy source to drive a motor and drive an automobile. The battery pack 2 can be charged or discharged by an inverter by the drive of a motor and / or an internal combustion engine. The battery pack 2 can be charged by a regenerative charging device coupled with the brakes. The battery pack 2 can be electrically connected to the motor of the automobile 1 via an inverter.

[0099] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and it goes without saying that a wide range of modifications and variations are possible within the equivalent scope of the technical concept of the present invention and the following claims by persons with ordinary skill in the art to which the present invention pertains.

[0100] In this specification, terms indicating direction such as up, down, left, and right are used, but these terms are for the sake of convenience of explanation only, and it is obvious to those skilled in the art that the direction can change depending on the position of the object in question, the position of the observer, etc.

Claims

1. A cell stack consisting of stacked battery cells, A module case for housing the cell stack, with a gas vent hole in the bottom plate, A venting guide member comprising a main body having the property of warping in shape due to heat, and a needle portion connected to the main body, The venting guide member is positioned on the bottom plate such that when the main body rises above a predetermined temperature, the main body bends, causing the needle portion to contact the battery cell, in a battery module.

2. The battery module according to claim 1, characterized in that the main body is made of dissimilar metals with different coefficients of thermal expansion and includes a first metal part and a second metal part stacked on top of each other.

3. The second metal portion has a higher coefficient of thermal expansion than the first metal portion. The battery module according to claim 2, characterized in that the venting guide member is positioned on the bottom plate of the module case such that the second metal portion faces the bottom plate of the module case.

4. The main body is, The battery module according to claim 1, characterized in that it includes a needle insertion hole into which the needle portion is inserted, and an elastic member disposed in the needle insertion hole and coupled with the needle portion.

5. The battery module according to claim 4, characterized in that the bottom plate of the module case includes a needle blocking portion configured to compress the elastic member and block the front of the needle portion so that the needle portion inserted into the needle insertion hole does not pop out.

6. The main body portion includes a rotating shaft portion formed to protrude from the side, The battery module according to claim 1, characterized in that the bottom plate of the module case is provided with a shaft mounting portion that engages with the rotating shaft portion.

7. The bottom plate of the module case includes a groove that is recessed to correspond to the main body, The battery module according to claim 1, characterized in that the venting guide member is inserted into the groove.

8. The battery module according to claim 1, characterized in that there are multiple needle portions, and the spacing between the needle portions corresponds to the thickness of the battery cell.

9. The aforementioned module case is An upper plate covering the upper part of the cell stack, A lower plate that covers the lower part of the cell stack and forms the bottom plate, A pair of side plates that cover both sides of the cell stack, The battery module according to claim 1, further comprising a pair of end covers that cover the front and rear of the cell stack, respectively.

10. The aforementioned battery cell is a pouch-type battery cell, The gas vent holes are provided at predetermined intervals along the width direction of the lower plate, The battery module according to claim 9, characterized in that the gas vent holes are provided at positions corresponding to the cell terraces formed by heat welding of the pouch sheet in the pouch-type battery cell, above and below.

11. The battery module according to claim 10, characterized in that the venting guide members are arranged alternately with the gas vent holes on the lower plate along the width direction of the lower plate.

12. A busbar electrically connected to electrode leads provided in the aforementioned battery cell, The present invention further includes a busbar frame that supports the busbar, has lead slots through which the electrode leads pass, and is attached to the front or rear of the cell stack, The battery module according to claim 1, wherein the busbars include a first busbar and a second busbar arranged to overlap the electrode leads, and the electrode leads are crimped and fixed between the first busbar and the second busbar.

13. The aforementioned battery cells are pouch-type battery cells, each with its wide surface raised and stacked in one direction. The cell stack includes a plurality of barrier plates that are sandwiched between the battery cells at predetermined intervals along one direction to restrict the movement of heat or gas between the battery cells. The battery module according to claim 12, characterized in that each of the plurality of barrier plates is joined to the busbar frame at its end so that the battery cells and gas vent holes are divided into a predetermined number of units.

14. A battery pack comprising a battery module according to any one of claims 1 to 13.

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