Immersion-cooled battery module, and battery pack and vehicle including same

Abstract

An immersion cooled battery module according to one embodiment of the present invention includes a battery assembly including a plurality of battery cells; a module case having an opening at at least one end and accommodating the battery assembly and a coolant in an internal space connected to the opening; a sealing cover inserted into the opening to airtightly cover the opening; and an end cover coupled to the opening into which the sealing cover is inserted to cover the opening, wherein the sealing cover includes a wall portion facing an edge of the module case forming the opening at a predetermined interval, and at least a portion of a peripheral portion of the end cover is configured to be inserted and coupled between the edge of the opening and the wall portion.

Description

[Technical Field]

[0001] This application claims priority based on Korean Patent Application No. 10-2022-0151508, filed on November 14, 2022, and the entire contents disclosed in the specification and drawings of that application are incorporated herein by reference.

[0002] The present invention relates to an immersion-cooled battery module, and a battery pack and vehicle including the same, and more particularly to an immersion-cooled battery module in which rechargeable battery cells are cooled by direct contact with a coolant, and a battery pack and vehicle including the same. [Background technology]

[0003] Generally, secondary batteries refer to batteries that can be repeatedly charged and discharged, such as lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, etc. The most basic secondary battery cell provides an output voltage of about 2.5V to 4.2V.

[0004] In recent years, as such secondary batteries have been applied to devices and systems requiring high output voltages and large charging capacities, such as electric vehicles and energy storage systems (ESS), battery modules in which a number of battery cells are densely arranged in a limited space and connected in series, parallel, or a combination of series and parallel, and battery packs in which such battery modules are even more densely arranged and connected in series, parallel, or a combination of series and parallel, have become widely used. In order for such battery modules and battery packs in which a number of battery cells are densely arranged in a limited space to operate normally, the temperature of the battery cells must be maintained at an appropriate level.

[0005] However, as disclosed in Patent Document 1, the conventional technology cools the battery cells using a heat sink 300 that contacts only the lower edge portion of the battery cell. Therefore, this conventional technology has problems such as poor cooling performance of the battery cell and difficulty in preventing thermal runaway that occurs in the battery cell. Furthermore, this conventional technology cannot control fires that occur when a battery cell experiences thermal runaway, making it difficult to prevent chain reactions of thermal runaway in other battery cells and other battery modules around the battery cell where thermal runaway occurs.

[0006] In addition, as disclosed in Patent Document 2, the conventional technology of using insulating oil to cool battery cells built into a battery module has a problem in that the opening of a frame 200 that houses a battery cell stack 100 is sealed with an end plate 300 having a simple structure, which always poses a risk of insulating oil leakage and reduces the durability and safety of the sealing structure. Furthermore, this conventional technology provides battery module cases 200, 300 for each battery cell stack, and supplies and discharges insulating oil through independent piping 500, 600, 700 for each case 200, 300, requiring a lot of space for installing the insulating oil piping, which not only increases the manufacturing cost of a battery pack including the battery module, but also increases the overall volume and weight of the battery pack, thereby reducing the energy density. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Korean Patent Publication No. 10-2019-0053574 [Patent Document 2] Korean Patent Publication No. 10-2021-0048855 Summary of the Invention [Problem to be solved by the invention]

[0008] The technical problem to be solved by the present invention is to provide a liquid-cooled battery module that improves the cooling performance of the battery module to prevent thermal runaway or cascading thermal runaway of battery cells included in the battery module, as well as a battery pack and a vehicle including the same.

[0009] Another technical problem to be solved by the present invention is to provide a liquid-cooled battery module that can minimize the risk of cooling oil leakage and improve energy density, as well as a battery pack and a vehicle including the same. [Means for solving the problem]

[0010] According to one aspect of the present invention, there is provided a liquid immersion cooled battery module including: a battery assembly including a plurality of battery cells; a module case having an opening at at least one end and accommodating the battery assembly and a coolant in an internal space connected to the opening; a sealing cover inserted into the opening to airtightly cover the opening; and an end cover coupled to the opening into which the sealing cover is inserted to cover the opening, wherein the sealing cover includes a wall portion facing an edge of the module case that forms the opening at a predetermined distance, and at least a portion of a peripheral portion of the end cover is configured to be inserted between the edge of the opening and the wall portion and coupled thereto.

[0011] In one embodiment, the sealing cover further includes a fixing portion protruding from the first surface toward the interior space, and a peripheral edge of the fixing portion may be configured to be attached and fixed to an inner surface of the module case.

[0012] In one embodiment, the module case may further include a sealing tape having one surface attached to the periphery of the fixing portion and the other surface attached to the inner surface of the module case.

[0013] In one embodiment, the end cover may include a main body that covers the opening, an inner peripheral edge that extends from the main body toward the internal space of the module case and is inserted between the inner surface of the opening edge and the wall portion, and an outer peripheral edge that extends from the main body toward the outer surface of the opening edge and is attached to the outer surface of the opening edge.

[0014] In one embodiment, the inner periphery and the outer periphery are spaced apart from each other by a predetermined distance, and the opening edge can be configured to be inserted between the inner periphery and the outer periphery.

[0015] In one embodiment, a sealant may be interposed between the inner periphery and the inner surface of the opening edge, and a structural adhesive may be interposed between the outer periphery and the outer surface of the opening edge.

[0016] In one embodiment, a sealant may be interposed between the inner periphery and the wall portion.

[0017] In one embodiment, the battery assembly may include a plurality of sub-battery modules arranged side by side in a first direction, each of which includes a battery cell stack in which a plurality of battery cells are stacked, and an insulating block made of an insulating material and arranged between adjacent first and second sub-battery modules among the plurality of sub-battery modules.

[0018] In one embodiment, the insulating block may include a communication groove provided at a peripheral portion of the insulating block that is in close contact with the inner surface of the module case and that allows the coolant to pass from the first sub-battery module side to the second sub-battery module side.

[0019] In one embodiment, both ends of the insulating block may be coupled to the first sub-battery module and the second sub-battery module, respectively.

[0020] In one embodiment, the module case may include a stopper that protrudes from an inner surface of the module case to support the insulating block, thereby limiting movement of the insulating block.

[0021] In one embodiment, the cooling fluid may include an insulating oil or a dielectric liquid.

[0022] A battery pack according to another aspect of the present invention includes an immersion-cooled battery module according to any one of the above-described embodiments.

[0023] According to yet another aspect of the present invention, a vehicle includes an immersion-cooled battery module according to any one of the above-described embodiments. [Effects of the Invention]

[0024] According to one aspect of the present invention, battery cells accommodated inside a module case of a battery module are cooled through direct contact with a coolant flowing into the module case, thereby eliminating the need for battery cell cooling means such as a thermal pad and a heat sink, improving the cooling performance of the battery cells, and effectively preventing thermal runaway of the battery cells. Furthermore, when a fire occurs due to thermal runaway of a battery cell, the coolant filled inside the module case functions as a fire extinguisher, thereby preventing a chain reaction of thermal runaway of other battery cells and other battery modules around the battery cell where thermal runaway occurred.

[0025] In addition, the inner periphery of the first end cover covering the opening at one end of the module case is inserted and coupled between the wall portion of the first sealing cover inserted into the opening and the periphery of the opening, and the periphery of the opening is inserted and coupled between the inner periphery and outer periphery of the first end cover to form a serpentine sealing structure, thereby minimizing the risk of leakage of coolant that has flowed into the inside of the battery module.

[0026] In addition, the sealing tape, liquid sealant, and structural adhesive applied to the sealing structure triple-block the leakage of the coolant, thereby improving the durability and safety of the immersion-cooled battery module.

[0027] In addition, a plurality of sub-battery modules, each including a battery cell stack in which a plurality of battery cells are stacked, are housed in a single module case to form a single battery module, thereby reducing the number of battery modules included in the battery pack. As a result, in a battery pack including a plurality of battery modules, the space occupied by the inlets and outlets provided in each battery module and the space occupied by piping required to supply and recover coolant to and from each battery module are reduced, thereby reducing the manufacturing cost of the battery pack, as well as the overall volume and weight of the battery pack and improving the energy density of the battery pack.

[0028] In addition, an insulating module disposed between a first sub-battery module and a second sub-battery module disposed adjacent to each other among the plurality of sub-battery modules is coupled to the first sub-battery module and the second sub-battery module, respectively, to support the first sub-battery module and the second sub-battery module, thereby ensuring the electrical safety of the sub-battery modules while preventing damage to the sub-battery modules due to physical impacts, vibrations, etc.

[0029] In addition, by providing a communicating groove that allows the coolant to pass through at the peripheral portion of the insulating block that is in close contact with the inner surface of the module case, the flow of the coolant is made smoother, thereby further improving the cooling performance of the battery module.

[0030] Furthermore, one of the plurality of circuit boards corresponding to the plurality of sub-battery modules transmits the electrical signals sensed by itself and the electrical signals sensed by the remaining circuit boards to the outside through a single waterproof connector, thereby facilitating electrical connection between the battery module and an external electrical device, simplifying the wiring structure of a battery pack including a plurality of battery modules, and enabling the status of the battery module to be monitored for each sub-battery module.

[0031] In addition, since the waterproof connector is coupled to a sealing cover having an inlet or outlet and is disposed in a space reserved for connecting the inlet or outlet to a pipe, there is no need to reserve a separate space to enable the electrical connection of the waterproof connector within the battery pack, and the electrical connection of the waterproof connector is facilitated.

[0032] Furthermore, a person having ordinary skill in the art to which the present invention pertains will easily understand from the following description that various embodiments of the present invention can solve various technical problems not described above. [Brief explanation of the drawings]

[0033] [Figure 1] 1 is a perspective view showing an immersion-cooled battery module according to an embodiment of the present invention; FIG. [Figure 2] FIG. 2 is an exploded perspective view showing the immersion-cooled battery module shown in FIG. 1. [Figure 3] 1 is an exploded perspective view showing a battery assembly accommodated in a module case of an immersion-cooled battery module according to an embodiment of the present invention; [Figure 4] FIG. 4 is an enlarged view of an insulating block of the battery assembly shown in FIG. 3. [Figure 5] FIG. 5 is a vertical cross-sectional view showing a portion A1 of FIG. 4. [Figure 6] 1 is a perspective view showing a first sealing cover of an immersion-cooled battery module according to an embodiment of the present invention. FIG. [Figure 7] FIG. 4 is a vertical cross-sectional view showing a first sealing cover coupled to a module case. [Figure 8] FIG. 2 is a perspective view showing a first end cover of an immersion-cooled battery module according to an embodiment of the present invention. [Figure 9] 9 is a vertical cross-sectional view taken along line SS' of the first end cover shown in FIG. 8. FIG. [Figure 10] FIG. 4 is a vertical cross-sectional view showing a first end cover coupled to a module case. [Figure 11] FIG. 11 is an enlarged view showing a portion A2 of FIG. [Figure 12] 1 is a diagram illustrating a battery pack according to an embodiment of the present invention. [Figure 13] 1 is a diagram illustrating a vehicle according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0034] In order to clarify the solution to the technical problem of the present invention, the embodiments of the present invention will be described in detail with reference to the drawings. However, in the description of the present invention, if the description of related prior art may obscure the gist of the present invention, the description will be omitted.

[0035] Furthermore, the terms used in this specification are defined in consideration of the functions of the present invention, and may vary depending on the intentions or practices of the designer, manufacturer, etc. Therefore, the definitions of terms to be described below should be based on the entire contents of this specification.

[0036] For reference, the components of the present invention shown in the drawings may be partially or entirely reduced in size, enlarged, omitted, or simplified in order to facilitate technical understanding.

[0037] FIG. 1 is a perspective view showing an immersion-cooled battery module 10 according to one embodiment of the present invention.

[0038] FIG. 2 is an exploded perspective view showing the immersion-cooled battery module 10 shown in FIG.

[0039] 1 and 2, a battery module 10 according to an embodiment of the present invention is configured to cool battery cells housed in an internal space of a module case 100 by direct contact with a coolant. To this end, the battery module 10 may include a module case 100, a battery assembly 200, sealing covers 110, 110′, a waterproof connector 120, and end covers 130, 130′.

[0040] The module case 100 may have an opening at at least one end, and may be configured to accommodate the battery assembly 200 and a coolant in an internal space connected to the opening. For example, the module case 100 may be configured as a tube having an internal space extending in a first direction (Y-axis direction) and openings at both ends in the first direction.

[0041] The module case 100 may be made of a metal material having a certain strength, and may be integrally formed through an extrusion molding or sheet metal process to prevent leakage of the coolant.

[0042] The battery assembly 200 may include a plurality of battery cells and may be housed in the internal space of the module case 100. As will be described further below, the battery assembly 200 may include a plurality of sub-battery modules each including a battery cell stack in which a plurality of battery cells are stacked, and a plurality of circuit boards corresponding to the sub-battery modules. In this case, the plurality of circuit boards may be configured to sense electrical signals related to the plurality of sub-battery modules.

[0043] The sealing covers 110, 110' have at least one of an inlet 112 for introducing coolant into the internal space of the module case 100 and an outlet 112' for discharging the coolant that has flowed into the internal space to the outside of the module case 100, and can be configured to be inserted into an opening of the module case 100 to airtightly cover the opening.

[0044] The sealing covers 110, 110' may include a first sealing cover 110 having an inlet 112 and covering an opening at one end of the module case 100, and a second sealing cover 110' having an outlet 112' and covering an opening at the other end of the module case 100. In this case, high voltage (HV) terminals 114, 114' that provide output for the battery module 10 and a waterproof connector 120 may be disposed on the first sealing cover 110.

[0045] The waterproof connector 120 is coupled to and supported by the first sealing cover 110, and is electrically connected to the circuit board of the battery assembly 200, and may be configured to transmit electrical signals sensed by each circuit board to the outside of the module case 100.

[0046] The end covers 130, 130' may be configured to be coupled to and cover the openings of the module case 100 into which the sealing covers 110, 110' are inserted and coupled. The end covers 130, 130' may include a first end cover 130 that covers the opening at one end into which the first sealing cover 110 is inserted, and a second end cover 130' that covers the opening at the other end into which the second sealing cover 110' is coupled.

[0047] The coolant used in the present invention may include an insulating oil or a dielectric liquid having a high withstand voltage, for example, trioctyl phosphate (TOP), tributyl phosphate (TOB), triphenyl phosphate, trimethyl phosphate, or tripropyl phosphate.

[0048] In a modified embodiment, the modified module case that houses the battery assembly may be configured so that an opening is provided at only one end in the longitudinal direction, and the other end in the longitudinal direction is closed. Furthermore, the modified sealing cover that covers and seals the opening of the modified module case may be configured to have both an inlet and an outlet. According to this modified embodiment, the structures corresponding to the second sealing cover 110' and the second end cover 130' shown in FIGS. 1 and 2 can be omitted. In this case, the coolant that flows in through the inlet of the modified sealing cover may circulate through the internal space of the modified module case, cool the battery cells, and then be discharged through the outlet of the modified sealing cover.

[0049] As described above, according to one embodiment of the present invention, the battery cells accommodated in the module case 100 of the battery module 10 are cooled through direct contact with the coolant flowing into the module case 100, thereby eliminating the need for battery cell cooling means such as a thermal pad and a heat sink, improving the cooling performance of the battery cells and effectively preventing thermal runaway of the battery cells. Furthermore, when a fire occurs due to thermal runaway of a battery cell, the coolant filled inside the module case functions as a fire extinguisher, thereby preventing a chain reaction of thermal runaway in other battery cells and other battery modules around the battery cell where thermal runaway occurred.

[0050] FIG. 3 is an exploded perspective view showing a battery assembly 200 housed in a module case of a liquid immersion cooling battery module according to an embodiment of the present invention.

[0051] As shown in FIG. 3, the battery assembly 200 may include a plurality of sub-battery modules 210 and 220, an insulating block 230, and a plurality of circuit boards 240 and 250.

[0052] Each of the plurality of sub-battery modules 210, 220 includes a battery cell stack in which a plurality of battery cells 212, 222 are stacked, and may be accommodated in the internal space of the module case 100 and arranged side by side along the longitudinal direction (Y-axis direction) of the module case 100.

[0053] For example, the battery assembly 200 may include a first sub-battery module 210 and a second sub-battery module 220.

[0054] In this case, the first sub-battery module 210 may include a first battery cell stack in which a plurality of battery cells 212 are stacked in the width direction (X-axis direction) of the module case 100, a first bus bar frame 214 arranged at one end of the first battery cell stack in the longitudinal direction (Y-axis direction), and a second bus bar frame 216 arranged at the other end of the first battery cell stack in the longitudinal direction.

[0055] The second sub-battery module 220 may also include a second battery cell stack in which a plurality of battery cells 222 are stacked in the width direction (X-axis direction) of the module case 100, a third bus bar frame 224 arranged at one end of the second battery cell stack in the longitudinal direction (Y-axis direction), and a fourth bus bar frame 226 arranged at the other end of the second battery cell stack in the longitudinal direction.

[0056] The first bus bar frame 214, the second bus bar frame 216, the third bus bar frame 224, and the fourth bus bar frame 226 may each be configured to support a bus bar 214a that electrically connects the electrode lead of a battery cell to the electrode lead of another battery cell or to a separate terminal.

[0057] In addition, the battery cells constituting the battery cell stack of each of the sub-battery modules 210 and 220 may include a pouch-type battery cell in which an electrode assembly and an electrolyte material are housed inside a pouch-type case.

[0058] The insulating block 230 may be made of an insulating material and may be disposed between the first sub battery module 210 and the second sub battery module 220, which are disposed adjacent to each other among the plurality of sub battery modules. One end of the insulating block 230 may be coupled to the first sub battery module 210, and the other end of the insulating block 230 may be coupled to the second sub battery module 220.

[0059] In this manner, the insulating block 230 is coupled to the adjacent sub-battery modules 210, 220 and supports these sub-battery modules 210, 220, thereby ensuring the electrical safety of the sub-battery modules 210, 220 and preventing damage to the sub-battery modules 210, 220 due to physical impacts, vibrations, etc.

[0060] The plurality of circuit boards 240, 250 may include circuit boards in a number corresponding to the plurality of sub-battery modules 210, 220. For example, the plurality of circuit boards 240, 250 may include a first circuit board 240 corresponding to the first sub-battery module 210 and a second circuit board 250 corresponding to the second sub-battery module 220. The plurality of circuit boards 240, 250 may be accommodated in the internal space of the module case 100 and configured to sense electrical signals related to the plurality of sub-battery modules 210, 220.

[0061] Therefore, the plurality of circuit boards 240, 250 may be disposed on the upper ends of the corresponding sub-battery modules, and each of the plurality of circuit boards 240, 250 may be made of a flexible printed circuit board (FPCB).

[0062] In this case, the first circuit board 240 may be configured to sense a first electrical signal related to the first sub battery module 210 among the plurality of sub battery modules 210, 220. The first electrical signal may include an electrical signal indicating an output voltage, an output current, or a charging state of the battery cells included in the first sub battery module 210.

[0063] The second circuit board 250 may be configured to sense a second electrical signal related to the second sub battery module 220 among the plurality of sub battery modules 210, 220. The second electrical signal may include an electrical signal indicating an output voltage, an output current, or a charging state of the battery cells included in the second sub battery module 220.

[0064] In addition, the first circuit board 240 may be configured to receive a second electrical signal from the second circuit board 250, collect the first electrical signal sensed by itself and the second electrical signal received from the second circuit board 250, and transmit the collected signal to the outside through the waterproof connector 120.

[0065] Therefore, the battery assembly 200 may further include a flat flexible cable (FFC) 260. The flat flexible cable 260 may be configured to electrically connect the first circuit board 240 and the second circuit board 250 and transmit a second electrical signal sensed by the second circuit board 250 to the first circuit board 240.

[0066] Generally, the length of a battery module corresponds to the length of the battery cells that make up the battery module. However, since the immersion-cooled battery module 10 according to one embodiment of the present invention includes multiple sub-battery modules 210, 220 arranged side by side in its longitudinal direction (Y-axis direction), it has a length more than twice that of a typical battery module including battery cells of the same size as the present invention. For example, while a typical battery module is manufactured with a length of about 500 mm to 610 mm, the immersion-cooled battery module 10 according to one embodiment of the present invention can be manufactured with a length of 1000 mm or more.

[0067] FIG. 4 is an enlarged view of the insulating block 230 of the battery assembly shown in FIG.

[0068] 4, the insulating block 230 may be disposed between the adjacent first and second sub battery modules 210 and 220. The insulating block 230 may be configured such that both ends thereof are coupled to the first and second sub battery modules 210 and 220, respectively. That is, one end of the insulating block 230 may be coupled to the first sub battery module 210, and the other end of the insulating block 230 may be coupled to the second sub battery module 220.

[0069] In one embodiment, the insulating block 230 may be configured so that its periphery is in close contact with the inner surface of the module case 100. In this case, the insulating block 230 may include a communication groove 232.

[0070] The communication groove 232 may be provided on the periphery of the insulating block 230 that is in close contact with the inner surface of the module case 100, and configured to allow the coolant that has flowed into the module case 100 to pass from the first sub-battery module 210 side to the second sub-battery module 220 side. Therefore, the communication groove 232 may have a shape that extends from the first sub-battery module 210 side to the second sub-battery module 220 side.

[0071] In addition, the communication groove 232 is configured to narrow from the first sub-battery module 210 side toward the second sub-battery module 220 side, thereby increasing the flow rate of the coolant passing through the communication groove 232. As a result, it is possible to prevent a phenomenon in which the flow rate of the coolant that has flowed into the module case 100 decreases as it moves from the first sub-battery module 210 side to the second sub-battery module 220 side, causing a decrease in cooling performance.

[0072] In one embodiment, the battery assembly 200 may further include a connecting member 218 that electrically connects the first sub-battery module 210 and the second sub-battery module 220. The connecting member 218 may be made of a conductive material such as metal.

[0073] In this case, the insulating block 230 may have a support groove 234 into which at least a portion of the connecting member 218 is inserted and supported.

[0074] FIG. 5 shows a vertical cross-sectional view of part A1 in FIG.

[0075] As shown in FIG. 5, one end of the insulating block 230 may be coupled to the second bus bar frame 216 of the first sub-battery module, and the other end of the insulating block 230 may be coupled to the fourth bus bar frame 226 of the second sub-battery module.

[0076] The second bus bar frame 216 may be configured to support bus bars or terminals electrically connected to the battery cells 212 of the first sub-battery module, and the fourth bus bar frame 226 may be configured to support bus bars or terminals electrically connected to the battery cells 222 of the second sub-battery module.

[0077] The connecting member 218 may be configured such that one end thereof is connected to a bus bar or terminal arranged on the second bus bar frame 216, and the other end thereof extends along the support groove 234 of the insulating block 230 to be connected to a bus bar or terminal arranged on the fourth bus bar frame 226.

[0078] In one embodiment, the second bus bar frame 216 may include a first coupling protrusion 216a, and the insulating block 230 may include a first coupling groove 236a into which the first coupling protrusion 216a is inserted for coupling. In this case, the first coupling protrusion 216a may extend in a first direction (e.g., the Y-axis direction) toward the insulating block 230 and then bend in a second direction (e.g., the Z-axis direction) intersecting the first direction. The first coupling groove 236a may be configured to be molded to fit the first coupling protrusion 216a.

[0079] In addition, the fourth bus bar frame 226 may include second coupling protrusions 226a, and the insulating block 230 may include first coupling grooves 236b into which the second coupling protrusions 226a are inserted for coupling. In this case, the second coupling protrusions 226a may extend in a third direction toward the insulating block 230 and then bend in a fourth direction (e.g., the Z-axis direction) intersecting the third direction. The second coupling grooves 236b may be configured to be molded to fit the second coupling protrusions 226a.

[0080] In addition, in one embodiment, the module case 100 may include stoppers 102 that protrude from an inner surface defining the internal space thereof to support the insulating block 230 and limit movement of the insulating block 230. In this case, the stoppers 102 are in close contact with both ends of the insulating block 230 and can limit movement of the insulating block 230 to prevent the insulating block 230 from moving out of its normal position and biasing toward the first sub-battery module 210 or the second sub-battery module 220.

[0081] In this manner, the insulating block 230 is coupled to the sub-battery module to support the sub-battery module, and the stopper 102 restricts the movement of the insulating block 230, thereby ensuring the electrical safety of the sub-battery module and preventing damage to the sub-battery module due to physical impact, vibration, etc.

[0082] FIG. 6 is a perspective view showing a first sealing cover 110 of a liquid immersion cooling type battery module according to an embodiment of the present invention.

[0083] 6, the first sealing cover 110 may include an inlet 112 for introducing a coolant into the internal space of the module case 100, and may be configured to be inserted into an opening of the module case 100 to airtightly cover the opening. To this end, the first sealing cover 110 may include a cover portion 110a, a fixing portion 110b, and a wall portion 110c.

[0084] The cover portion 110a may be configured such that its periphery has a shape that matches with the opening of the module case 100 and is inserted into the opening.

[0085] The fixing portion 110b may be configured to protrude from a first surface (e.g., a first surface of the cover portion 110a) of the first sealing cover 110 adjacent to the internal space of the module case 100 toward the internal space, and have its periphery attached to and fixed to the inner surface of the module case 100. To this end, a double-sided adhesive sealing tape may be attached to the periphery of the fixing portion 110b facing the inner surface of the module case 100.

[0086] The wall portion 110c may be configured to correspond to the surface opposite to the first surface, protrude from a second surface (e.g., a second surface of the cover portion 110a) of the first sealing cover 110 facing the first end cover 130, and face an opening edge of the module case 100 forming the opening at a predetermined distance. In this case, the wall portion 110c may be configured in the form of a roof (loop) that goes around the periphery of the cover portion 110a.

[0087] As will be described further below, the wall portion 110c of the first sealing cover 110 may form a first insertion groove together with the peripheral portion of the cover portion 110a and the opening edge of the module case 100. The inner peripheral edge of the end cover 130, which will be described below, may be inserted into and coupled to the first insertion groove.

[0088] Meanwhile, high voltage (HV) terminals 114, 114′ that provide the output of the battery module 10 and a waterproof connector 120 may be arranged on a second surface of the first sealing cover 110. In this case, the waterproof connector 120 may be fixed to the first sealing cover 110 by a fastening member 120a such as a bolt.

[0089] FIG. 7 is a vertical cross-sectional view showing the first sealing cover 110 coupled to the module case 100. As shown in FIG.

[0090] As shown in FIG. 7, the first sealing cover 110 has an inlet 112 for introducing a coolant into the internal space of the module case 100, and can be inserted into an opening at one end of the module case 100 to airtightly cover the opening.

[0091] Therefore, the cover portion 110 a of the first sealing cover 110 may be configured so that its periphery is fitted to the opening of the module case 100 .

[0092] The fixing portion 110b of the first sealing cover 110 protrudes from the first surface of the cover portion 110a toward the inner space of the module case 100, and its periphery is attached to the inner surface of the module case 100 and fixed thereto.

[0093] Therefore, a sealing tape 118a capable of double-sided adhesion may be attached to the peripheral surface of the fixing portion 110b that faces the inner surface of the module case 100. In this case, the sealing tape 118a may have a multi-layer structure in which an adhesive layer is provided on each side of a base layer made of a waterproof material.

[0094] For example, the base layer of the sealing tape 118a may include one or more material layers made of one or more of polyimide, polypropylene, polyethylene, and polyethylene terephthalate, and the adhesive layer of the sealing tape 118a may be made of one or more of polymethyl methacrylate, polyethyl methacrylate, and polybutyl methacrylate.

[0095] The sealing tape 118a may further include a release paper covering the adhesive layer, which can be removed by an operator immediately before applying the sealing tape 118a.

[0096] The wall portion 110c of the first sealing cover 110 may be configured to protrude from a second surface of the first sealing cover 110, which is opposite to the first surface adjacent to the internal space of the module case 100, in a direction away from the internal space of the module case 100, and to face an edge of the module case 100 forming the opening with a predetermined gap therebetween. As described above, the wall portion 110c may be configured in the form of a roof that goes around the periphery of the cover portion 110a.

[0097] The wall portion 110c of the first sealing cover 110 may form a first insertion groove G1 together with the peripheral portion of the cover portion 110a and the inner surface of the module case 100 that forms the periphery of the opening. A liquid sealant 118b, such as sealing glue, may be applied to the inner surface of the first insertion groove G1.

[0098] In addition, a structural adhesive 104 having high shear strength may be applied to the outer surface of the opening edge of the module case 100. Such structural adhesive 104 may include a polymer alloy adhesive or a polyimide adhesive. As will be described further below, the outer peripheral edge of a first end cover 130 (described below) may be attached and fixed to the outer surface of the opening edge to which the structural adhesive 104 is applied.

[0099] Meanwhile, the first sealing cover 110 may have a through hole 116 into which at least a portion of the waterproof connector 120 is inserted.

[0100] The waterproof connector 120 may also include a connector body 122 , a contact pin 124 , and a connecting pin 126 .

[0101] The connector body 122 may be coupled to a second surface of the first sealing cover 110, which is adjacent to the internal space of the module case 100, and a second surface of the first sealing cover 110 opposite to the first surface, and configured to cover the opening of the through hole 116 formed in the second surface. The connector body 122 of the waterproof connector 120 may be made of insulating polymer synthetic resin and may be fixed to the first sealing cover 110 by a fastening member such as a bolt.

[0102] In one embodiment, the waterproof connector 120 may further include a sealing member 124a interposed between the connector body 122 and the second surface of the first sealing cover 110 to seal the periphery of the opening of the through-hole 116. In this case, the sealing member 124a may include a sealant or a gasket, or may include both.

[0103] The contact pins 124 may be supported by the connector body 122 and configured to extend in a direction away from the internal space of the module case 100. Such contact pins 124 may come into contact with and be electrically connected to corresponding contact pins of a corresponding connector (not shown) connected to the waterproof connector 120. For this reason, the contact pins 124 may be made of a conductive metal material. The waterproof connector 120 may include one or more such contact pins 124.

[0104] The connecting pin 126 may be configured to be electrically connected to the contact pin 124, extend from the connector body 122 through the through hole 116 toward the internal space of the module case 100, and be electrically connected to the first circuit board 240 of the multiple circuit boards 240, 250 housed in the module case 100. For this reason, the connecting pin 126 may be made of a conductive metal material. The waterproof connector 120 may include one or more such connecting pins 126.

[0105] In one embodiment, the contact pins 124 and the connecting pins 126 may be integrally formed. Also, in one embodiment, the connector body 122 may be integrally formed with the contact pins 124 and the connecting pins 126 through an insert molding process.

[0106] Meanwhile, the battery module 10 may further include a connection circuit board 128 and a cable 128 a for electrical connection between the waterproof connector 120 and the first circuit board 240 .

[0107] In this case, the connecting circuit board 128 may be coupled to a first surface of the first sealing cover 110 adjacent to the internal space of the module case 100, cover the opening at the other end of the through hole 116 formed in the first surface, and be electrically connected to the connecting pin 126. To this end, the connecting circuit board 128 may have via holes into which the connecting pins 126 are inserted. The connecting pins 126 inserted into the via holes of the connecting circuit board 128 may be further fixed to the connecting circuit board 128 through a soldering process.

[0108] The cable 128a may be configured such that one end is electrically connected to the connection circuit board 128 and the other end is electrically connected to the first circuit board 240. The cable 128a may include a flexible flat cable (FFC). The first circuit board 240 connected to the cable 128a in this manner may be electrically connected to the bus bar 214a connected to the electrode lead of the battery cell 212. In this case, the bus bar 214a may be coupled to and fixed to the first bus bar frame 214.

[0109] 1 and 2, the second sealing cover 110' covering the opening at the other end of the module case 100 includes an outlet 112' for discharging the coolant that has flowed into the internal space of the module case 100, and may be inserted into the opening at the other end to airtightly cover the opening at the other end. Therefore, the second sealing cover 110' may include components corresponding to the cover portion 110a, the fixing portion 110b, and the wall portion 110c of the first sealing cover 110. However, the second sealing cover 110' does not have components corresponding to the HV terminals 114, 114' or the waterproof connector 120.

[0110] FIG. 8 is a perspective view showing a first end cover 130 of an immersion-cooled battery module according to one embodiment of the present invention.

[0111] 8, the first end cover 130 may be configured to be coupled to the opening of the module case 100 into which the first sealing cover 110 is inserted and to cover the opening. The first end cover 130 may have an inlet hole 132 through which the inlet 112 of the first sealing cover 110 passes, and a connector hole 138 through which at least a portion of the waterproof connector 120 is inserted and exposed to the outside.

[0112] In addition, the first end cover 130 may further include terminal holes 134, 134' through which the HV terminals 114, 114' arranged on the first sealing cover 110 pass, and support portions 136, 136' that support the ends of the HV terminals 114, 114' that pass through the terminal holes 134, 134' and extend to the outside.

[0113] FIG. 9 is a vertical cross-sectional view of the first end cover 130 taken along line SS' shown in FIG.

[0114] 9, the first end cover 130 may have a cap structure that covers the opening of the module case 100 into which the first sealing cover 110 is inserted. Also, at least a portion of the peripheral edge of the first end cover 130 may be configured to be inserted and coupled between the edge of the opening of the module case 100 and the wall portion 110c of the first sealing cover 110. In this case, the first end cover 130 may include a body that covers the opening, and an inner peripheral edge 130a and an outer peripheral edge 130b that extend from the body.

[0115] The inner peripheral edge 130a may extend from the main body of the first end cover 130 toward the internal space of the module case 100 and be inserted between the opening edge of the module case 100 and the wall portion 110c of the first sealing cover 110. That is, the inner peripheral edge 130a may be configured to be inserted into a first insertion groove G1 formed by the opening edge of the module case 100 and the peripheral portion and wall portion 110c of the first sealing cover 110.

[0116] The outer peripheral edge 130b extends toward the outer surface of the module case 100 and can be attached to the outer surface portion to which the structural adhesive 104 is applied.

[0117] In addition, the inner periphery 130a and the outer periphery 130b may be spaced apart at a predetermined interval to form a second insertion groove G2 into which the opening edge of the module case 100 is inserted.

[0118] FIG. 10 is a vertical cross-sectional view showing the first end cover 130 coupled to the module case 100. As shown in FIG.

[0119] 10, the inner peripheral edge 130a of the first end cover 130 extends from the main body of the first end cover 130 toward the internal space of the module case 100 and can be inserted between the opening edge of the module case 100 and the wall portion 110c of the first sealing cover 110. That is, the inner peripheral edge 130a can be configured to be inserted into a first insertion groove G1 formed by the opening edge of the module case 100 and the peripheral portion and wall portion 110c of the first sealing cover 110.

[0120] Furthermore, the outer peripheral edge 130b of the first end cover 130 extends toward the outer surface of the module case 100 and can be attached to the outer surface portion to which the structural adhesive is applied.

[0121] In addition, the opening edge of the module case 100 can be inserted between the inner periphery 130a and the outer periphery 130b of the first end cover 130 and coupled thereto. That is, the opening edge of the module case 100 can be inserted into the second insertion groove G2 formed between the inner periphery 130a and the outer periphery 130b and coupled thereto.

[0122] Meanwhile, the terminal end of the waterproof connector 120 can be inserted into and supported in a connector hole 138 of the first end cover 130 .

[0123] FIG. 11 is an enlarged view showing the A2 portion of FIG.

[0124] 11 , the inner periphery 130a of the first end cover 130 extends toward the interior space of the module case 100 and may be inserted into and coupled to a first insertion hole G1 formed between the opening edge 100a of the module case 100 and the wall portion 110c of the first sealing cover 110. In this case, the first insertion hole G1 may be filled with a liquid sealant 118b. As a result, the liquid sealant 118b may be interposed between the inner periphery 130a of the first end cover 130 and the wall portion 110c of the first sealing cover 110. The liquid sealant 118b may also be interposed between the inner periphery 130a of the first end cover 130 and the opening edge 100a of the module case 100.

[0125] An outer peripheral edge 130b of the first end cover 130 extends toward the outer surface of the opening edge 100a, and can be attached to the outer surface of the opening edge 100a to which the structural adhesive 104 has been applied.

[0126] Meanwhile, the opening edge 100a of the module case 100 may be inserted into a second insertion groove formed between the inner periphery 130a and the outer periphery 130b of the first end cover 130 and coupled together. As a result, a liquid sealant 118b may be interposed between the inner periphery 130a and the inner surface of the opening edge 100a, while a structural adhesive 104 may be interposed between the outer periphery 130b and the outer surface of the opening edge 100a.

[0127] In this way, the inner periphery 130a of the first end cover 130 is inserted and coupled between the wall portion 110c of the first sealing cover 110 and the opening edge 100a of the module case 100, and the opening edge 100a of the module case 100 is inserted and coupled between the inner periphery 130a and the outer periphery 130b of the first end cover 130, thereby forming a serpentine-shaped sealing structure, and as a result, the risk of leakage of coolant that has flowed into the inside of the battery module 10 can be minimized.

[0128] In addition, the sealing tape 118a, liquid sealant 118b, and structural adhesive 104 applied to the sealing structure of the battery module 10 provide a triple barrier to coolant leakage, thereby improving the durability and safety of the liquid-immersion cooled battery module 10.

[0129] 1 and 2, the second end cover 130', which covers the opening at the other end of the module case 100 together with the second sealing cover 110', may have an outlet hole through which the outlet 112' of the second sealing cover 110' passes, and may cover the opening at the other end through which the second sealing cover 110' is inserted. Therefore, the second end cover 130' may include structures corresponding to the inner periphery 130a and outer periphery 130b of the first end cover 130. Meanwhile, the second end cover 130' does not include structures corresponding to the terminal holes 134, 134' and connector hole 138 of the first end cover 130.

[0130] FIG. 12 shows a battery pack 20 according to one embodiment of the present invention.

[0131] 12, a battery pack 20 according to an embodiment of the present invention may include a battery module 10 according to an embodiment of the present invention and pack cases 22, 24 that accommodate one or more battery modules 10. The pack cases 22, 24 may have a plurality of mounting spaces for accommodating and mounting a plurality of battery modules.

[0132] 12 , the battery pack 20 may further include a coolant tank for storing the coolant, a pump for circulating the coolant stored in the coolant tank through the supply pipe 26 and the recovery pipe 28, and a chiller for removing heat from the coolant recovered through the recovery pipe 28.

[0133] The battery pack 20 may further include various electrical components (not shown) that control the charge / discharge operation of the battery modules 10 housed in the pack cases 22 and 24, or that monitor the SOC (State of Charge), SOH (State of Health), etc. These electrical components may be housed in the pack cases 22 and 24 together with the battery modules 10.

[0134] FIG. 13 shows a vehicle 2 according to one embodiment of the present invention.

[0135] As shown in FIG. 13, a vehicle 2 according to one embodiment of the present invention may include one or more battery modules 10 according to any one of the various embodiments described above, or may include at least one battery pack 20 including the battery module 10.

[0136] The battery module 10 or the battery pack 20 applied to the vehicle 2 can provide electrical energy required for various operations of the vehicle 2.

[0137] For reference, the battery module according to an embodiment of the present invention may be applied to an energy storage system (ESS) and various electric devices in addition to a vehicle.

[0138] As described above, according to one embodiment of the present invention, the battery cells accommodated in the module case of the battery module are cooled through direct contact with the coolant flowing into the module case, thereby eliminating the need for battery cell cooling means such as a thermal pad and a heat sink, improving the cooling performance of the battery cells, and effectively preventing thermal runaway of the battery cells. Furthermore, when a fire occurs due to thermal runaway of a battery cell, the coolant filled inside the module case functions as a fire extinguisher, thereby preventing a chain reaction of thermal runaway of other battery cells and other battery modules around the battery cell where thermal runaway occurred.

[0139] In addition, the inner periphery of the first end cover covering the opening at one end of the module case is inserted and coupled between the wall portion of the first sealing cover inserted into the opening and the periphery of the opening, and the periphery of the opening is inserted and coupled between the inner periphery and outer periphery of the first end cover to form a serpentine sealing structure, thereby minimizing the risk of leakage of coolant that has flowed into the inside of the battery module.

[0140] In addition, the sealing tape, liquid sealant, and structural adhesive applied to the sealing structure triple-block the leakage of the coolant, thereby improving the durability and safety of the immersion-cooled battery module.

[0141] In addition, a plurality of sub-battery modules, each including a battery cell stack in which a plurality of battery cells are stacked, are housed in a single module case to form a single battery module, thereby reducing the number of battery modules included in the battery pack. As a result, in a battery pack including a plurality of battery modules, the space occupied by the inlets and outlets provided for each battery module and the space occupied by piping required to supply coolant to and recover coolant from each battery module are reduced, thereby reducing the manufacturing cost of the battery pack, as well as the overall volume and weight of the battery pack and improving the energy density of the battery pack.

[0142] In addition, an insulating module disposed between a first sub-battery module and a second sub-battery module disposed adjacent to each other among the plurality of sub-battery modules is coupled to the first sub-battery module and the second sub-battery module, respectively, to support the first sub-battery module and the second sub-battery module, thereby ensuring the electrical safety of the sub-battery modules while preventing damage to the sub-battery modules due to physical impacts, vibrations, etc.

[0143] In addition, by providing a communicating groove that allows the coolant to pass through at the peripheral portion of the insulating block that is in close contact with the inner surface of the module case, the flow of the coolant is made smoother, thereby further improving the cooling performance of the battery module.

[0144] Furthermore, one of the plurality of circuit boards corresponding to the plurality of sub-battery modules transmits the electrical signals sensed by itself and the electrical signals sensed by the remaining circuit boards to the outside through a single waterproof connector, thereby facilitating electrical connection between the battery module and an external electrical device, simplifying the wiring structure of a battery pack including a plurality of battery modules, and enabling the status of the battery module to be monitored for each sub-battery module.

[0145] In addition, since the waterproof connector is coupled to a sealing cover having an inlet or outlet and is disposed in a space reserved for connecting the inlet or outlet to a pipe, there is no need to reserve a separate space to enable the electrical connection of the waterproof connector within the battery pack, and the electrical connection of the waterproof connector is facilitated.

[0146] Furthermore, it goes without saying that the embodiments of the present invention can solve various other technical problems in the art, as well as in related arts, other than those described in this specification.

[0147] Although the present invention has been described with reference to specific embodiments, those skilled in the art will clearly understand that various modifications can be made within the technical scope of the present invention. Therefore, the above-described embodiments should be considered from an illustrative perspective, not a limiting perspective. In other words, the true scope of the technical concept of the present invention is defined by the claims, and all differences within the scope of equivalents thereto should be construed as being included in the present invention. [Explanation of symbols]

[0148] 10. Immersion-cooled battery module 20 Battery Pack 22 pack case 24 pack case 26 Supply pipe 28 Recovery pipe 100 module case 102 Stopper 104 Structural adhesive 110 First sealing cover 110' Second ceiling cover 112 Entrance 112' Exit 114 High Voltage (HV) terminal 114' High Voltage (HV) Terminal 116 Through hole 120 Waterproof Connector 122 Connector body 124 contact pins 126 connecting pin 128 Connected Circuit Board 130 First end cover 130' 2nd end cover 132 Entrance hole 134 Terminal hole 134' terminal hole 136 Support part 136' Support 138 Connector hole 200 Battery Assembly 210 First sub-battery module 212 battery cells 214 First bus bar frame 216 Second bus bar frame 218 Connecting member 220 Second sub-battery module 222 battery cells 224 3rd bus bar frame 226 4th bus bar frame 230 Insulation Block 232 Communication groove 234 Support groove 240 1st circuit board 250 2nd circuit board 260 Flexible Flat Cable (FFC; Flat Flexible Cable)

Claims

1. a battery assembly including a plurality of battery cells; a module case having an opening at at least one end and containing the battery assembly and a coolant in an internal space connected to the opening; a sealing cover that is inserted into the opening and airtightly covers the opening; an end cover coupled to the opening into which the sealing cover is inserted and covering the opening; A liquid-immersion cooled battery module comprising: the sealing cover includes a wall portion facing an opening edge of the module case that defines the opening at a predetermined interval, At least a portion of the peripheral edge of the end cover is configured to be inserted between the opening edge and the wall portion and coupled thereto, The end cover is a main body covering the opening; an inner peripheral edge of the main body extending toward the internal space of the module case and inserted between the inner surface of the opening edge and the wall portion; an outer peripheral edge extending from the main body toward the outer surface of the opening edge and attached to the outer surface of the opening edge; Including, The inner periphery and the outer periphery are spaced apart from each other by a predetermined distance, the opening edge is configured to be inserted between the inner periphery and the outer periphery.

2. The sealing cover further includes a fixing portion protruding from the first surface toward the interior space, The liquid-immersion-cooled battery module according to claim 1 , wherein a peripheral edge of the fixing portion is attached to and fixed to an inner surface of the module case.

3. The liquid-immersion-cooled battery module according to claim 2 , further comprising a sealing tape having one surface attached to the periphery of the fixing portion and the other surface attached to the inner surface of the module case.

4. 2. The liquid-immersion cooled battery module according to claim 1, wherein a sealant is interposed between the inner peripheral edge and the inner surface of the opening edge, and a structural adhesive is interposed between the outer peripheral edge and the outer surface of the opening edge.

5. The liquid-immersion-cooled battery module according to claim 1 , wherein a sealant is interposed between the inner peripheral edge and the wall portion.

6. The battery assembly includes: a plurality of sub-battery modules each including a battery cell stack in which a plurality of battery cells are stacked, the sub-battery modules being arranged side by side in a first direction; an insulating block made of an insulating material and disposed between adjacent first and second sub-battery modules among the plurality of sub-battery modules; 10. The liquid-cooled battery module of claim 1, comprising:

7. 7. The liquid immersion cooling type battery module according to claim 6, wherein the insulating block is provided with a communication groove provided at a peripheral portion of the insulating block that is in close contact with an inner surface of the module case, the communication groove allowing the coolant to pass from the first sub-battery module side to the second sub-battery module side.

8. The immersion-cooled battery module according to claim 6 , wherein both ends of the insulating block are coupled to the first sub-battery module and the second sub-battery module, respectively.

9. 9. The liquid immersion cooling battery module according to claim 8, wherein the module case includes a stopper that protrudes from an inner surface of the module case to support the insulating block, thereby limiting movement of the insulating block.

10. The liquid-immersion cooled battery module according to claim 1 , wherein the cooling liquid comprises insulating oil or dielectric liquid.

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

12. A vehicle comprising the immersion cooled battery module of any one of claims 1 to 10.

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