Rechargeable battery module

Abstract

A rechargeable battery module includes: a plurality of battery cells stacked in a first direction; a pair of end plates at opposite ends of the plurality of battery cells in the first direction; a pair of side plates at opposite sides of the plurality of battery cells in a second direction intersecting the first direction to connect the pair of end plates to each other; a heat diffusion portion between battery cells of the plurality of battery cells and having a first melting point; and a rigid / insulating portion embedded inside the heat diffusion portion to provide rigidity or insulation, and having a second melting point lower than the first melting point.

Description

TECHNICAL FIELD

[0001] The disclosure relates to a rechargeable battery module, and more particularly, to a rechargeable battery module having heat dissipation performance and heat transfer blocking performance. BACKGROUND

[0002] Unlike primary batteries, rechargeable batteries are a type of battery that can be repeatedly charged and discharged. Small-capacity rechargeable batteries can be used for portable small electronic devices such as smartphones, laptop computers, and camcorders. Large-capacity and high-density rechargeable batteries can be used for power sources or energy storage to drive a motor of, for example, a hybrid vehicle and an electric vehicle.

[0003] Rechargeable batteries can be used as rechargeable battery modules including a plurality of battery cells connected in series and / or in parallel to be able to drive a motor of, for example, a hybrid vehicle requiring a relatively high energy density.

[0004] For example, a rechargeable battery module can be formed by stacking a plurality of battery cells provided in an amount corresponding to a required amount of power in a frame to implement a rechargeable battery module of a relatively high power (for example, a rechargeable battery module used with an electric vehicle).

[0005] The module frame includes side plates and end plates. When the battery cells in the module expand due to chemical reactions caused by charging and discharging, the side plates hold the end plates to prevent or substantially prevent movement of the end plates and hold the battery cells and internal components from being separated from the module. In this case, the side plates must hold a limited space.

[0006] The battery cells are arranged in the module frame, and an insulating cell for preventing or substantially preventing heat transfer, insulation, and enhancing the rigidity of the module is used between the battery cells. Heat transfer is determined by the time for which a first battery cell becomes an event and then a second battery cell becomes an event. Double-sided tape or an adhesive attached to the insulating cell connects all of the battery cells in the plurality of battery cells, thereby enhancing the mechanical rigidity of the module.

[0007] In addition, a cooling plate is installed at the bottom of the module to prevent or substantially prevent the allowable temperature (for example, 60℃) of the battery cells from being exceeded during rapid charging, life, and driving modes of the battery cells of the module. The cooling plate suppresses the temperature rise of the battery cells by the cooling temperature, cooling flow rate, and cooling flow rate (speed) of the cooling fluid. SUMMARY

[0008] According to an aspect of one or more embodiments of the disclosure, there is provided a rechargeable battery module having a heat dissipation effect on the entire outer surface of a battery cell (e.g., five surfaces except for the lower surface of the battery cell provided with a cooling plate) to achieve rapid charging of a high-capacity battery cell.

[0009] According to another aspect of one or more embodiments of the disclosure, there is provided a rechargeable battery module that can improve heat dissipation performance between battery cells and can have a heat transfer blocking performance between the battery cells.

[0010] According to one or more embodiments, a rechargeable battery module includes a plurality of battery cells stacked in a first direction, a pair of end plates located at opposite ends of the plurality of battery cells in the first direction, a pair of side plates located at opposite sides of the plurality of battery cells in a second direction intersecting the first direction to connect the pair of end plates to each other, a heat diffusion portion located between the battery cells of the plurality of battery cells and having a first melting point, and a rigid / insulating portion embedded inside the heat diffusion portion to provide rigidity or insulation and having a second melting point lower than the first melting point.

[0011] The rechargeable battery module can further include a cooling plate under the battery cells.

[0012] The rechargeable battery module can further include a bottom diffusion portion at a bottom of the battery cells, and the bottom diffusion portion can be in contact with the cooling plate.

[0013] The rechargeable battery module can further include a bus bar on an upper side of the battery cells to electrically connect electrode terminals of the battery cells.

[0014] The rechargeable battery module can further include an upper diffusion portion on the upper side of the battery cells except for the electrode terminals, and the upper diffusion portion can be in contact with the bus bar.

[0015] The heat diffusion portion can be formed of silicon (Si) or liquid crystal polymer (LCP). The rigid / insulating portion can be formed of polypropylene (PP) or polycarbonate (PC).

[0016] The heat diffusion portion can exist in a solid state at room temperature, and can have a larger volume at the time of solidification than in a liquid state.

[0017] The battery cells can be configured to have a first temperature on their surfaces in the event of an incident, the heat diffusion portion can have a melting point of a second temperature higher than the first temperature, and the rigid / insulating portion can have a melting point of a third temperature lower than the first temperature.

[0018] The first temperature can be 500℃ to 700℃, the heat-diffusing portion can be formed of silicon having a melting point of a second temperature, and the rigid / insulating portion can be formed of polypropylene (PP) having a melting point of a third temperature.

[0019] The heat-diffusing portion can include a first side portion on an inner side of the side plate on opposite sides of the stacked battery cells in the second direction, and the rigid / insulating portion can include a second side portion formed flat within the first side portion having a first thickness.

[0020] The heat-diffusing portion can further include a first end portion on an inner side of the end plate on opposite sides of the stacked battery cells in the first direction, and the rigid / insulating portion can further include a second end portion formed flat within the first end portion having a second thickness greater than the first thickness.

[0021] The rigid / insulating portion can further include a terminal mounting portion protruding from the second end portion outward of the first end portion to form on an end plate of the pair of end plates, and the terminal mounting portion can fix a final terminal connected to the bus bar.

[0022] The heat-diffusing portion can further include a first main portion between the battery cells of the plurality of battery cells, the rigid / insulating portion can further include a second main portion embedded inside the first main portion of the heat-diffusing portion, the first main portion of the heat-diffusing portion can be coupled to the first side portion between the stacked battery cells, and the second main portion of the rigid / insulating portion can be coupled to the second side portion in a plane between the stacked battery cells.

[0023] The rigid / insulating portion can include a plurality of column portions extending between the stacked battery cells in a third direction intersecting the first direction and the second direction and can be spaced apart in the second direction to have a width in the first direction, and a connection portion connecting adjacent column portions to each other, and the heat-diffusing portion can be configured to embed the column portions and the connection portion.

[0024] The column portions can be formed as cylinders having a diameter, and the heat-diffusing portion can be located on opposite sides of the column portions and the connection portion in the first direction to form a gap greater than the diameter between the column portions and the battery cells of the plurality of battery cells.

[0025] According to one or more embodiments of the disclosure, a heat-diffusing portion is provided between battery cells, and a rigid / insulating portion is embedded in the heat-diffusing portion, such that during normal operation, the heat-diffusing portion has a heat dissipation effect, and upon an event, the rigid / insulating portion melts to form an air layer in the heat-diffusing portion, such that the battery cells can be thermally separated. Accordingly, heat transfer between the battery cells can be blocked during an event, while having a heat dissipation performance during normal operation. Attached Figure Description

[0026] Figure 1 A perspective view illustrating a rechargeable battery module according to an embodiment of the present disclosure.

[0027] Figure 2 Example of a device with a cooling plate Figure 1 A front view of a rechargeable battery module.

[0028] Figure 3 Example in Figure 2 A partial front view of the cooling plate with the middle side panel removed.

[0029] Figure 4 Example in Figure 2 A partial front view of the busbar with the middle side plate removed.

[0030] Figure 5 Examples along Figure 2 The planar cross-section diagram of line VV.

[0031] Figure 6 Example Figure 5 A partially enlarged cross-sectional view.

[0032] Figure 7 Examples along Figure 1 The longitudinal cross-section diagram taken from line VII-VII.

[0033] Figure 8 Example Figure 6 Enlarged view of the heat diffusion section and the rigid / insulating section.

[0034] Figure 9 An enlarged cross-sectional view is shown, illustrating the setting... Figure 6 The thermal diffusion section and the rigid / insulating section between the individual battery cells.

[0035] Figure 10 Examples along Figure 6 The longitudinal cross-section diagram taken from line XX.

[0036] Figure label description

[0037] 10: Cell battery; 11, 12: Electrode terminals

[0038] 20: End plate; 30: Side plate

[0039] 40: Thermal diffusion section; 41: Bottom diffusion section

[0040] 42: Upper diffusion section; 50: Rigid / insulating section

[0041] 51: Column section 52: Connecting section

[0042] 60: cooling plate 70: bus bar

[0043] 71, 72: final terminal 401: first side portion

[0044] 402: first end portion 501: second side portion

[0045] 502: second end portion 511: terminal mounting portion

[0046] D: diameter G: gap

[0047] t1: first thickness t2: second thickness

[0048] W: width DETAILED DESCRIPTION

[0049] The present disclosure will be described more fully hereinafter with reference to the accompanying drawings, in which some embodiments of the present disclosure are shown. As those skilled in the art will appreciate, the described embodiments can be modified in various different ways without departing from the spirit or scope of the present disclosure. The drawings and description are to be read in conjunction with one another, and it is intended that the present disclosure be understood, not only as the solution claimed for the separate embodiments set forth, but also as other solutions both individually and in combination.

[0050] Also, the word "comprise" and variations such as "comprises" or "comprising" are not necessarily limited to cases where there is an explicit description of the features that make up the base. It is to be understood that the word "comprise" and variations thereof do not necessarily exclude other features than the ones mentioned.

[0051] Also, in this specification, unless explicitly described to the contrary, the word "comprise" and variations such as "comprises" or "comprising" are to be construed in an inclusive sense, that is to say, in the sense of "including, but not limited to."

[0052] The singular form includes the plural form, unless the context clearly dictates otherwise.

[0053] It is to be understood that the terms "first", "second", and the like, used herein do not connote any hierarchy or order, but are used for the purpose of naming. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the example embodiments of the present disclosure. The terms "first", "second", and the like, are used herein merely to differentiate one element from another. The singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise.

[0054] Also, terms such as "below," "under," "above," and "on" are used to describe the relationship of one configuration to another as shown in the drawings. However, the terms are used as relative concepts, are described with reference to the directions indicated in the drawings, and are not intended to limit.

[0055] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this concept belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0056] Figure 1 A perspective view of a rechargeable battery module according to an embodiment of the present disclosure is illustrated. Referring to Figure 1 , the rechargeable battery module according to an embodiment includes a plurality of battery cells 10, a pair of end plates 20, a pair of side plates 30, a heat diffusion portion 40, and a rigid / insulating portion 50 (see Figure 6 ).

[0057] In an embodiment, the battery cells 10 are formed in a prismatic shape and are stacked in a first direction (e.g., an x-axis direction). The pair of end plates 20 is disposed on both ends or opposite ends of the stacked battery cells 10 in the first direction to support the battery cells 10 in the x-axis direction.

[0058] The pair of side plates 30 is disposed on both sides or opposite sides of the battery cells 10 in a second direction (e.g., a y-axis direction) intersecting the first direction to connect the pair of end plates 20 to each other and support the battery cells 10 in the y-axis direction.

[0059] Figure 2 A front view of the rechargeable battery module according to Figure 1 , provided with a cooling plate is illustrated; Figure 3 A partial front view of the cooling plate in a state in which Figure 2 the side plates are removed is illustrated.

[0060] Referring to Figures 1 to 3 , the rechargeable battery module according to an embodiment further includes a cooling plate 60 provided on a lower side of the battery cells 10 (or under the battery cells 10). The cooling plate 60 is provided on a bottom of the battery cells 10 so as not to exceed an allowable temperature (e.g., 60℃) of the battery cells 10, such as during fast charging, lifespan, and driving modes of the rechargeable battery module. In an embodiment, the cooling plate 60 suppresses a temperature rise of the battery cells 10 based on a cooling temperature, a flow rate, and a flow rate of a cooling fluid.

[0061] The rechargeable battery module further includes a bottom diffusion portion 41 disposed on the bottom of the battery cell 10. That is, the bottom diffusion portion 41 and the heat diffusion portion 40 connect the lower side of the battery cell 10 and the battery cell 10 to facilitate diffusion of heat generated between the battery cells 10. In an embodiment, the heat diffusion portion 40 exists in a solid state at room temperature, and has a higher density in a liquid state than in a solid state and a larger volume upon solidification than in a liquid state.

[0062] The bottom diffusion portion 41 disposed at the bottom of the battery cell 10 is in contact with the cooling plate 60. Accordingly, heat of the battery cell 10 can be easily transferred and dissipated to the cooling plate 60 through the heat diffusion portion 40 and the bottom diffusion portion 41.

[0063] For long-distance driving of a vehicle equipped with the rechargeable battery module according to an embodiment, the rechargeable battery module has a higher capacity (e.g., 182 Ah / battery cell), and the time required for fast charging is reduced, for example, from 28 minutes to about 15 minutes.

[0064] For example, due to the demand for high capacity and fast charging, the cooling plate 60 can be used to control the temperature at 15℃. Accordingly, the temperature deviation between the bottom of the prismatic battery cell 10 and the upper end of the battery cell 10 can be close to 30℃, which can hinder the performance and safety of the battery cell 10.

[0065] The maximum allowable temperature deviation or ideal temperature deviation between the upper end and the lower end of the battery cell 10 can be 8℃. In an embodiment, in order to achieve the allowable temperature deviation, the heat diffusion portion 40 and the rigid / insulation portion 50 are used. When the battery cell 10 is normally operated, the heat diffusion portion 40 quickly performs heat transfer to stably perform heat diffusion.

[0066] In this case, the rigid / insulation portion 50 is embedded in the heat diffusion portion 40 to provide rigidity to the rechargeable battery module when the battery cell 10 is normally operated. In addition, the rigid / insulation portion 50 is configured to melt in the embedded state of the rigid / insulation portion 50 during an event of the battery cell 10, thereby forming an air layer inside the heat diffusion portion 40.

[0067] The air layer embedded in the heat diffusion portion 40 provides insulation between the adjacent battery cells 10 and blocks heat diffusion between the battery cells 10. Air has a thermal conductivity of 0.02 Kcal / Mh℃, which is lower than that of glass fiber, water, glass, stainless steel, steel plate, or aluminum, thereby providing excellent heat diffusion blocking performance.

[0068] Figure 4 A partial front view of the busbar is illustrated in a state in which the side plate is removed. Figure 2 A partial front view of the busbar is illustrated in a state in which the side plate is removed.Figure 1 、 Figure 2 and Figure 4 The rechargeable battery module according to an embodiment further includes bus bars 70, according to an embodiment.

[0069] The bus bars 70 are provided on the upper side of the battery cells 10 to electrically connect the electrode terminals 11, 12 of the battery cells 10. In an embodiment, the bus bars 70 can connect the battery cells 10 in parallel, and a plurality of bus bars 70 can connect the parallel connections in series again. Two of the bus bars 70 are electrically connected to final terminals 71, 72 that output final power of the rechargeable battery module.

[0070] The rechargeable battery module further includes an upper diffusion portion 42 formed on the upper side of the battery cells 10 other than the electrode terminals 11, 12. That is, the upper diffusion portion 42 and the thermal diffusion portion 40 connect the upper side of the battery cells 10 and the battery cells 10 to facilitate diffusion of heat generated between the battery cells 10 to the upper side of the battery cells 10.

[0071] The upper diffusion portion 42 disposed on the upper side of the battery cells 10 is in contact with the bus bars 70. In an embodiment, the thermal diffusion portion 40 or the upper diffusion portion 42 is made of a non-conductive material, so that a bus bar support between the bus bars 70 and the electrode terminals 11, 12 can be omitted. The removal or omission of the bus bar support simplifies the structure of the rechargeable battery module.

[0072] Figure 5 FIG. 4 illustrates a plan cross-sectional view taken along lines V-V of FIG. 3; Figure 2 FIG. 5 illustrates a partial enlarged cross-sectional view of a portion of FIG. 4. Figure 6 Figure 5 FIG. 6 illustrates a plan cross-sectional view taken along lines V-V of FIG. 5.

[0073] Referring to FIGS. 3 to 6, Figures 1 to 6 The thermal diffusion portion 40, the bottom diffusion portion 41, and the upper diffusion portion 42 have a first melting point and can be made of, for example, silicon (Si).

[0074] In an embodiment, the thermal diffusion portion 40, the bottom diffusion portion 41, and the upper diffusion portion 42 made of silicon (Si) are provided on the entire outer surface of the battery cells 10, and the bottom diffusion portion 41 is in close contact with the cooling plate 60, so that the heat diffusion effect of the battery cells 10 can be maximized or increased. In an embodiment, the silicon (Si) surrounds the entire outer surface of the battery cells 10, and the silicon is connected to the battery cells 10 in the form of a nano-pore bonding structure.

[0075] ​The rigid / insulation portion 50 is embedded in the heat diffusion portion 40, has a second melting point lower than the first melting point, and provides rigidity or insulation. In an embodiment, for example, the heat diffusion portion 40 is made of silicon (Si), and the rigid / insulation portion 50 can be made of polypropylene (PP).

[0076] In an embodiment, the heat diffusion portion 40 can be made of liquid crystal polymer (LCP) containing silicon (Si) or carbon, and the rigid / insulation portion 50 can be made of polycarbonate (PC).

[0077] The battery cell 10 has a first temperature on its surface in the event of an event such as thermal runaway. The heat diffusion portion 40 has a second temperature higher than the first temperature of the melting point. The rigid / insulation portion 50 has a third temperature lower than the first temperature of the melting point.

[0078] For example, the first temperature of the battery cell 10 during the event is 500℃ ~ 700℃. The second temperature of silicon (Si) forming the heat diffusion portion 40 has a melting point of 1414℃, and thus does not melt at the first temperature during the event and diffuses the first temperature to the entire surface of the battery cell 10 and the entire surface of the rechargeable battery module. Silicon (Si) has a melting point of 1414℃ and a thermal conductivity of 149 W / mK (about 82% of the thermal conductivity of aluminum). In an embodiment, the melting point of the heat diffusion portion 40 is 335℃ ~ 1414℃.

[0079] In an embodiment, the third temperature of polypropylene (PP) forming the rigid / insulation portion 50 has a melting point of 165℃ and melts due to the first temperature of the battery cell 10, thereby forming an air layer in the heat diffusion portion 40. The air layer is provided inside the heat diffusion portion 40 to block heat diffusion to the battery cell 10 adjacent thereto.

[0080] In other words, the heat of the battery cell 10 causing the event can be blocked from diffusing to the adjacent battery cell 10 by the air layer formed by the melting of the rigid / insulation portion 50, and can be quickly dissipated by the cooling plate 60. Polypropylene (PP) has a melting point of 165℃ and a thermal conductivity of 0.2 W / mK. In an embodiment, the melting point of the rigid / insulation portion 50 is 145℃ ~ 165℃.

[0081] In an embodiment, the melting point difference between the heat-diffusing portion 40 and the rigid / insulating portion 50 can be 2 to 10 times the melting point of the rigid / insulating portion 50. In an embodiment, the thermal conductivity of the heat-diffusing portion 40 ranges from 10 W / mK to 149 W / mK, and the thermal conductivity of the rigid / insulating portion 50 ranges from 0.2 W / mK to 0.5 W / mK. The thermal conductivity difference between the heat-diffusing portion 40 and the rigid / insulating portion 50 can range from 20 times to 745 times the thermal conductivity of the rigid / insulating portion 50.

[0082] In an embodiment, the heat-diffusing portion 40 includes a first main portion between the battery cells 10 in the plurality of battery cells 10 and a first side portion 401 on the inner side of the side plate 30 on both sides or opposite sides of the stacked battery cells 10 in the second direction (e.g., the y-axis direction), and the rigid / insulating portion 50 includes a second main portion embedded inside the first main portion of the heat-diffusing portion 40 and a second side portion 501 having a first thickness t1 formed flat in the first side portion 401.

[0083] In an embodiment, the first side portion 401 and the second side portion 501 are formed to correspond to the entire area of the side plate 30 so as to prevent or substantially prevent heat generated from the battery cells 10 from diffusing into the side plate 30.

[0084] In an embodiment, the heat-diffusing portion 40 further includes a first end portion 402 on the inner side of the end plate 20 on both sides or opposite sides of the stacked battery cells 10 in the first direction (e.g., the x-axis direction), and the rigid / insulating portion 50 further includes a second end portion 502 having a second thickness t2 greater than the first thickness t1 formed flat in the first end portion 402 (see Figure 7 ).

[0085] In an embodiment, the first end portion 402 and the second end portion 502 are formed to correspond to the entire area of the end plate 20 so as to prevent or substantially prevent heat generated from the battery cells 10 from diffusing into the end plate 20.

[0086] The first end portion 402 of the heat-diffusing portion 40 and the second end portion 502 of the rigid / insulating portion 50 are molded together with the end plate 20 in normal operating conditions rather than in battery event conditions. In an embodiment, the end plate 20 formed of aluminum provides mechanical rigidity.

[0087] Figure 7 A longitudinal cross-sectional view taken along the line VII-VII of Figure 1 is illustrated. See Figure 1 , Figure 2 and Figure 7The rigid / insulating portion 50 includes a terminal mounting portion 511 protruding from the second end portion 502 to the first end portion 402 to form on the end plate 20.

[0088] The terminal mounting portion 511 fixes the final terminals 71, 72 coupled or connected to the bus bar 70. The terminal mounting portion 511 can prevent or substantially prevent heat generated from the final terminals 71, 72 from being transferred to the bus bar 70 and the battery cells 10.

[0089] Figure 8 Illustration Figure 6 Partial enlarged view of the heat diffusion portion and the rigid / insulating portion; Figure 9 Illustrated enlarged cross-sectional view illustrating the heat diffusion portion and the rigid / insulating portion disposed between Figure 6 battery cells in the stack of battery cells 10; Figure 10 Illustrated longitudinal cross-sectional view taken along the line X-X of Figure 6

[0090] Referring to Figures 8 to 10 , between the stacked battery cells 10, a first main portion of the heat diffusion portion 40 is coupled to the first side portion 401, and in the plane between the stacked battery cells 10, a second main portion of the rigid / insulating portion 50 is coupled to the second side portion 501.

[0091] Thus, in an embodiment, the heat diffusion portion 40 including the first side portion 401 separates and surrounds each of the battery cells 10. The rigid / insulating portion 50 including the second side portion 501 is embedded in the heat diffusion portion 40 separating and surrounding each of the battery cells 10 so as to separate and surround each of the battery cells 10 together with the heat diffusion portion 40.

[0092] In an embodiment, for example, the rigid / insulating portion 50 includes a plurality of column portions or a plurality of columns 51 and a connection portion 52 coupling or connecting adjacent column portions 51 to each other. The column portions 51 are formed to extend between the stacked battery cells 10 along a third direction (e.g., z-axis direction) intersecting the first direction (e.g., x-axis direction) and the second direction (e.g., y-axis direction) and are spaced apart from each other along the second direction to have a width in the first direction. In an embodiment, the heat diffusion portion 40 is configured to embed the column portions 51 and the connection portion 52.

[0093] ​In an embodiment, the heat diffusion portion 40 is located between adjacent battery cells 10 together with the embedded pillar portion 51 and the connecting portion 52. When the pillar portion 51 is melted, an adequate air layer is formed within the heat diffusion portion 40. The connecting portion 52 is capable of connecting to the air layer in the entire outer surface area of the battery cell 10 without reducing the rigidity of the heat diffusion portion 40 at the time of melting.

[0094] In an embodiment, the pillar portion 51 is formed as a cylinder having a diameter D, and the heat diffusion portion 40 is provided on both sides or opposite sides of the pillar portion 51 and the connecting portion 52 in a first direction (e.g., x-axis direction) to form a gap G greater than the diameter D between the pillar portion 51 and the battery cell 10.

[0095] At the time of melting, the pillar portion 51 has a size that can form an adequate air layer while securing the gap G, and at the time of non-melting, the connecting portion 52 prevents or substantially prevents a reduction in the rigidity of the heat diffusion portion 40 between the battery cells 10.

[0096] In an embodiment, for example, the diameter D of the pillar portion 51 is 1 mm ~ 3 mm, but can be adjusted according to the capacity of the battery cell 10. In an embodiment, the width W of the connecting portion 52 is 0.2 mm ~ 0.6 mm. In an embodiment, the width W can be 20% ~ 50% of the diameter D (W = (0.2 ~ 0.5)D).

[0097] The ratio of the width W to the diameter D can be selectively applied according to the number of battery cells 10 in the rechargeable battery module, the length of the rechargeable battery module (e.g., in the x-axis direction), and the ratio of the weight of the battery cell 10 to the weight of the entire rechargeable battery module.

[0098] In the present embodiment, the pillar portion 51 is exemplified as a cylinder; however, for example, the pillar portion 51 can be formed as any of a square pillar, a rhombic pillar, a regular octagonal pillar, a regular dodecagonal pillar, and a star-shaped pillar. According to the shape of the pillar portion 51, the integrity of the pillar portion 51 and the heat diffusion portion 40 can be enhanced.

[0099] While the disclosure has been described in connection with what is considered to be some of the exemplary embodiments, it is understood that the disclosure is not limited to the disclosed embodiments, but is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims.

Claims

1. A rechargeable battery module, characterized by The rechargeable battery module includes: a plurality of battery cells stacked in a first direction; a pair of end plates at opposite ends of the plurality of battery cells in the first direction; a pair of side plates at opposite sides of the plurality of battery cells in a second direction intersecting the first direction to connect the pair of end plates to each other; a heat diffusion portion between battery cells of the plurality of battery cells and having a first melting point; and a rigid / insulating portion embedded inside the heat diffusion portion to provide rigidity or insulation and having a second melting point lower than the first melting point.

2. The rechargeable battery module of claim 1, wherein, The rechargeable battery module further includes a cooling plate under the battery cells.

3. The rechargeable battery module of claim 2, wherein, The rechargeable battery module further includes a bottom diffusion portion at a bottom of the battery cells, and the bottom diffusion portion is in contact with the cooling plate.

4. The rechargeable battery module of claim 1, wherein, The rechargeable battery module further includes a busbar on an upper side of the battery cells to electrically connect electrode terminals of the battery cells.

5. The rechargeable battery module of claim 4, characterized in that the rechargeable battery module further includes an upper diffusion portion on an upper side of the battery cells other than the electrode terminals, and the upper diffusion portion is in contact with the busbar.

6. The rechargeable battery module of claim 1, wherein, The heat diffusion portion is formed of silicon or a liquid crystal polymer.

7. The rechargeable battery module of claim 6, wherein, The rigid / insulating portion is formed of polypropylene or polycarbonate.

8. The rechargeable battery module of claim 1, wherein, The heat diffusion portion exists in a solid state at room temperature and has a higher density in a liquid state than in a solid state and a larger volume upon solidification than in a liquid state.

9. The rechargeable battery module of claim 1, wherein the battery cells are configured to have a first temperature on a surface thereof in an event situation, the heat diffusion portion has a melting point of a second temperature higher than the first temperature, and the rigid / insulating portion has a melting point of a third temperature lower than the first temperature.

10. The rechargeable battery module of claim 9, wherein the first temperature is 500℃ to 700℃, the heat diffusion portion is formed of silicon having the melting point of the second temperature, and the rigid / insulating portion is formed of polypropylene having the melting point of the third temperature.

11. The rechargeable battery module of claim 1, wherein the heat diffusion portion includes a first side portion inside the side plates on opposite sides of the stacked battery cells in the second direction, and the rigid / insulating portion includes a second side portion formed flat inside the first side portion having a first thickness.

12. The rechargeable battery module of claim 11, wherein the heat diffusion portion further includes a first end portion inside the end plates on opposite ends of the stacked battery cells in the first direction, and the rigid / insulating portion further includes a second end portion formed flat inside the first end portion having a second thickness greater than the first thickness.

13. The rechargeable battery module of claim 12, wherein The rigid / insulating portion further includes a terminal mounting portion protruding from the second end portion to outside of the first end portion to form on an end plate of the pair of end plates, and The terminal mounting portion fixes a final terminal connected to a bus bar on an upper side of the battery cell. 14.The rechargeable battery module according to claim 11, wherein The heat diffusion portion further includes a first main portion between the battery cells of the plurality of battery cells, The rigid / insulating portion further includes a second main portion embedded inside the first main portion of the heat diffusion portion, Between the stacked battery cells, the first main portion of the heat diffusion portion is coupled to the first side portion, and Between the stacked battery cells, the second main portion of the rigid / insulating portion is coupled to the second side portion. 15.The rechargeable battery module according to claim 1, wherein The rigid / insulating portion includes a plurality of column portions extending between the stacked battery cells in a third direction intersecting the first direction and the second direction and spaced apart in the second direction to have a width in the first direction, and a connection portion connecting adjacent column portions to each other, and The heat diffusion portion is configured to embed the column portions and the connection portion. 16.The rechargeable battery module according to claim 15, wherein The column portion is formed as a cylinder having a diameter, and The heat diffusion portion is located on opposite sides of the column portion and the connection portion in the first direction to form a gap between the column portion and the battery cell of the plurality of battery cells that is greater than the diameter.

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