Battery module and battery pack including same

Abstract

A battery module according to one embodiment of the present invention includes at least one battery cell assembly including a plurality of cylindrical battery cells arranged with their sides adjacent to each other; a case that houses the battery cell assembly; a fixing resin layer that is disposed on at least one of longitudinal ends of the cylindrical battery cells and fixes the cylindrical battery cells; and a heat transfer resin layer that is formed between the fixing resin layer and the case, and between a side of the battery cell assembly and the case, and is in contact with the fixing resin layer and the case.

Description

[Technical field]

[0001] [Cross-reference to related applications] This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0100168 dated July 29, 2021, and all contents disclosed in the documents of that Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a battery module including cylindrical battery cells and a battery pack including the same, and more particularly to a battery module capable of efficiently dissipating heat generated from the battery cells to the outside and a battery pack including the same. [Background technology]

[0003] Recently, as the price of energy sources rises due to the depletion of fossil fuels and concerns about environmental pollution grow, the demand for environmentally friendly alternative energy sources has become an essential factor for future life. Therefore, research into various power generation technologies such as atomic, solar, wind, and tidal power is ongoing, and there is also a lot of interest in power storage devices to use the energy produced in this way more efficiently.

[0004] Furthermore, as technological development and demand for mobile devices and battery-powered vehicles increases, the demand for batteries as an energy source is rapidly increasing, and as a result, much research is being conducted on batteries that meet various requirements. In particular, in terms of materials, there is a high demand for lithium secondary batteries such as lithium ion batteries and lithium ion polymer batteries, which have advantages such as high energy density, discharge voltage, and output stability.

[0005] Secondary batteries are classified according to the structure of the electrode assembly, which is a stacked structure of positive electrodes, negative electrodes, and a separator interposed between the positive and negative electrodes.Typical examples include a jelly-roll type (wound type) electrode assembly in which long sheet-type positive electrodes and negative electrodes are wound with a separator interposed therebetween, and a stack type (lamination type) electrode assembly in which a plurality of positive electrodes and negative electrodes cut into units of a predetermined size are stacked in sequence with a separator interposed therebetween.Recently, in order to solve the problems of the jelly-roll type electrode assembly and the stack type electrode assembly, a stack / folding type electrode assembly has been developed, which is an electrode assembly with a more advanced structure that is a combination of the jelly-roll type and the stack type, and has a structure in which unit cells, in which a predetermined unit of positive electrodes and negative electrodes are stacked with a separator interposed therebetween, are positioned on a separator film and then wound in sequence.

[0006] The electrode assembly is then housed in a pouch case, a cylindrical can, a square case, or the like depending on the intended use to manufacture a battery.

[0007] Among these, cylindrical batteries have the advantages of being easy to manufacture and having a high energy density per weight, and are used as an energy source for a variety of devices, from portable computers to battery-powered automobiles. Also, a battery module including multiple cylindrical batteries can be used as an energy source for small automobiles, etc.

[0008] However, in the case of a battery module including a plurality of cylindrical batteries, the energy density is high, and therefore it is necessary to more efficiently dissipate the heat generated in the batteries to the outside. To this end, a large number of components have been assembled in the past for heat dissipation. However, in this case, there is a problem that the number of components inside the pack increases the thermal resistance, making it difficult to obtain a sufficient heat dissipation effect. Summary of the Invention [Problem to be solved by the invention]

[0009] The problem to be solved by the present invention is to provide a battery module including cylindrical batteries, which can obtain a sufficient heat dissipation effect by reducing the thermal resistance inside the battery module while maintaining structural rigidity, and a battery pack including the same.

[0010] The problems that the present invention is intended to solve are not limited to those mentioned above, and problems not mentioned will be clearly understood by those having ordinary skill in the art to which the present invention pertains from this specification and the attached drawings. [Means for solving the problem]

[0011] A battery module according to one embodiment of the present invention includes at least one battery cell assembly including a plurality of cylindrical battery cells arranged with their sides adjacent to each other; a case that houses the battery cell assembly; a fixing resin layer that is disposed on at least one of longitudinal ends of the plurality of cylindrical battery cells and fixes the plurality of cylindrical battery cells; and a heat transfer resin layer that is formed between the fixing resin layer and the case, and between a side of the battery cell assembly and the case, and is in contact with the fixing resin layer and the case.

[0012] The battery cell assembly may further include an intermediate case surrounding side surfaces of the plurality of cylindrical battery cells.

[0013] The heat transfer resin layer may also be formed between the intermediate case and the case.

[0014] The case has a tube shape with an open upper and lower portion, and an upper cover and a lower cover can be coupled to the upper and lower portions, respectively.

[0015] The upper cover may include a plurality of resin injection holes for injecting a heat transfer resin to form the heat transfer resin layer.

[0016] The resin injection holes may be formed adjacent to the case.

[0017] The upper cover may be inserted into and coupled to the inside of the case and may include at least one first protrusion protruding from a side surface of the upper cover toward the case.

[0018] The intermediate case may include at least one second protrusion protruding from an outer surface of the intermediate case toward the case.

[0019] The case may include at least one third protrusion protruding from an inner surface of the case toward the intermediate case.

[0020] The upper cover may be inserted into and coupled to the inside of the case, and the case may include at least one fourth protrusion protruding from an inner surface of the case toward the upper cover.

[0021] A battery pack according to another embodiment of the present invention may include at least one battery module. Effect of the Invention

[0022] According to an embodiment of the present invention, in a battery module including cylindrical batteries, a sufficient heat dissipation effect can be obtained by reducing the thermal resistance inside the battery module, while maintaining structural rigidity.

[0023] The effects of the present invention are not limited to the effects described above, and effects not mentioned will be clearly understood by those having ordinary skill in the art to which the present invention pertains from this specification and the accompanying drawings. [Brief description of the drawings]

[0024] [Figure 1] 1 is a diagram showing a battery module according to an embodiment of the present invention; [Diagram 2]FIG. 2 is a diagram showing the battery module of FIG. 1 in a state before the case is assembled. [Diagram 3] FIG. 2 is a cross-sectional view of part A in FIG. [Figure 4] FIG. 2 is a diagram showing the top surface of FIG. [Diagram 5] 2 is a diagram illustrating a method of injecting a heat transfer resin for forming a heat transfer resin layer in the battery module of FIG. 1. FIG. [Figure 6] 5 is an enlarged view of a portion corresponding to portion C in FIG. 4 according to another embodiment of the present invention. FIG. [Figure 7] 1. FIG. 4 is a cross-sectional view of a portion corresponding to portion B in FIG. 1 according to another embodiment of the present invention. [Figure 8a] 1. FIG. 4 is a cross-sectional view of a portion corresponding to portion B in FIG. 1 according to still another embodiment of the present invention. [Figure 8b] 5 is a diagram showing a portion corresponding to portion C of FIG. 4 in still another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention may, however, be embodied in various different forms and should not be construed as being limited to the embodiments set forth herein.

[0026] In order to clearly explain the present invention, parts that are not necessary for the explanation will be omitted, and the same reference numerals will be used throughout the specification to refer to the same or similar components.

[0027] In addition, the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of explanation, and the present invention is not necessarily limited to those shown in the drawings. In the drawings, the thicknesses of various layers and regions are exaggerated to clearly express the layers and regions. In the drawings, the thicknesses of some layers and regions are exaggerated to facilitate explanation.

[0028] In addition, when a part such as a layer, film, region, or plate is said to be "on" or "above" another part, this includes not only the case where it is "directly on" the other part, but also the case where there is another part in between. Conversely, when a part is said to be "directly on" another part, it means that there is no other part in between. In addition, being "on" or "above" a reference part means being located above or below the reference part, and does not necessarily mean being located "on" or "above" the direction against gravity.

[0029] Additionally, throughout the specification, when a part is said to "comprise" a certain element, this means that it may further include other elements, but not to the exclusion of other elements, unless specifically stated to the contrary.

[0030] Also, throughout the specification, "in a plane" means when the subject part is viewed from above, and "in cross section" means when the subject part is cut vertically and viewed from the side.

[0031] BEST MODE FOR CARRYING OUT THE DISCLOSURE Hereinafter, a battery module according to one embodiment of the present invention will be described with reference to FIGS.

[0032] FIG. 1 is a diagram showing a battery module according to one embodiment of the present invention, FIG. 2 is a diagram showing the state before the case of the battery module of FIG. 1 is assembled, FIG. 3 is a diagram showing a cross-section of part A of FIG. 1, FIG. 4 is a diagram showing the top surface of FIG. 1, and FIG. 5 is a diagram explaining a method of injecting heat transfer resin to form a heat transfer resin layer in the battery module of FIG. 1.

[0033] 1 to 5, a battery module 10 according to an embodiment of the present invention includes a battery cell assembly 100 including a plurality of cylindrical battery cells 110 arranged with their sides adjacent to each other, a case 300 that houses the battery cell assembly 100, a fixing resin layer 130 that is disposed on at least one of the longitudinal ends of the plurality of cylindrical battery cells 110 and fixes the plurality of cylindrical battery cells 110, and a heat transfer resin layer 400 that is formed between the fixing resin layer 130 and the case 300 and is in contact with the fixing resin layer 130 and the case 300. In addition, the battery cell assembly 100 further includes an intermediate case 120 that surrounds the sides of the cylindrical battery cells 110 that are disposed on the outside with the plurality of cylindrical battery cells 110 arranged in the array.

[0034] The battery cell assembly 100 has a structure in which cylindrical battery cells 110 are arranged with their sides adjacent to each other. That is, a plurality of cylindrical battery cells 110 formed long in the y-axis direction in the drawing are stacked with their sides adjacent to each other in the x-axis and y-axis directions to be arranged to have an overall hexahedral shape. Such a battery cell assembly 100 may include an intermediate case 120 arranged to surround the side of the cylindrical battery cell 110 arranged at the outermost position in a band shape. As shown in FIG. 2, the intermediate case 120 may be formed to surround the side of the cylindrical battery cell 110 except for the end in the length direction, i.e., both ends in the y-axis direction. Such an intermediate case 120 is formed to surround one layer of cylindrical battery cells 110, and two or more intermediate cases 120 may be included in one battery module 10 to include two or more battery cell assemblies 100. In the present embodiment, it is illustrated that two battery cell assemblies 100 arranged in parallel in the y-axis direction are included and an insulating cover 140 is arranged between them, but the present embodiment is not limited thereto.

[0035] The battery cell assembly 100 includes a fixing resin layer 130 disposed at one of the longitudinal ends of the cylindrical battery cells 110. Referring to Figures 2 and 3, the fixing resin layer 130 is disposed at the y-axis end of the cylindrical battery cells 110 in the drawings and serves to fix the cylindrical battery cells 110. The fixing resin layer 130 may be made of a resin such as silicone, urethane, epoxy, or acrylic, and is not particularly limited.

[0036] The battery cell assembly 100 is housed in a rectangular tube-shaped case 300, and an upper cover 210 and a lower cover 220 are respectively coupled to both ends of the case 300. However, the configuration of the case 300 and the covers 210 and 220 is not limited thereto and may be modified into various shapes.

[0037] In this embodiment, as shown in Figs. 1 and 2, a case 300 is included that is open at both ends in the z-axis direction. That is, the cylindrical battery cells 110 can be housed in the case 300 so as to be arranged in a direction parallel to the openings on both sides of the case 300. Also, as shown in Fig. 2, one end of the battery cell assembly 100 can be inserted through the portion that is open in the z-axis direction and housed inside the case 300. The case 300 can be made of a material with high thermal conductivity. For example, the case 300 can be made of a material such as aluminum that has low thermal resistance and high thermal conductivity. This allows heat generated from the cylindrical battery cells 110 to be effectively released to the outside.

[0038] A heat transfer resin layer 400 is disposed between the battery cell assembly 100 and the case 300. As shown in Fig. 5, the heat transfer resin layer 400 is formed by injecting a liquid heat transfer resin in the direction of the arrow from above while the battery cell assembly 100 is housed in the case 300, and then hardening the resin inside. To this end, as shown in Figs. 4 and 5, the upper cover 210 may include a plurality of resin injection holes 211. However, this configuration is not limited thereto, and the heat transfer resin may be injected in various forms between the battery cell assembly 100 and the case 300.

[0039] 3, the heat transfer resin layer 400 may be formed in contact with the fixing resin layer 130 and the case 300. As a result, heat generated from the cylindrical battery cell 110 is immediately transferred to the heat transfer resin layer 400 only through the fixing resin layer 130, and then immediately transferred to the case 300 which is in direct contact with the heat transfer resin layer 400, thereby allowing the heat to be efficiently released to the outside. Such a heat transfer resin layer 400 may be made of a material having high thermal conductivity, such as a thermal resin such as silicone, urethane, or epoxy resin.

[0040] In addition, the heat transfer resin layer 400 is also disposed between the battery cell assembly 100, particularly between the side of the battery cell assembly 100 and the case 300, not just between the fixing resin layer 130 and the case 300, but also on both sides in the x-axis direction in the drawing, i.e., between the middle case 120 and the case 300, thereby enabling heat generated from the internal battery cell assembly 100 to be effectively released to the outside.

[0041] As described above, according to the present embodiment, the cylindrical battery cell 110 is firmly fixed by the fixing resin layer 130, and the heat transfer resin layer 400, which is in direct contact with the fixing resin layer 130, is in direct contact with the case 300, so that the heat generated from the cylindrical battery cell 110 can be easily released to the outside without any additional configuration. In particular, since the heat transfer resin layer 400 and the case 300 are made of materials with high thermal conductivity and low thermal resistance, it is possible to prevent an increase in thermal resistance that may occur when a large number of parts are present and quickly release heat to the outside. In addition, since the heat transfer resin layer 400 is arranged to completely surround the battery cell assembly 100 even in the part where the fixing resin layer 130 is not arranged, it is possible to quickly release heat in all directions. At this time, since the heat transfer resin layer 400 directly contacts and surrounds the four sides of the battery cell assembly 100 and is in direct contact with the case 300, it is possible to eliminate an empty space or an air gap between the battery cell assembly 100 and the case 300 and maximize the heat dissipation effect.

[0042] At the same time, since the heat transfer resin layer 400 is formed by being poured in a liquid state and hardening internally, there is no empty space between the battery cell assembly 100 and the case 300 and all four sides are filled with heat transfer resin, which prevents the battery cell assembly 100 from moving inside the case 300. Therefore, the rigidity of the entire battery module 10 can be improved without the need for many intervening parts.

[0043] Next, a battery module according to another embodiment of the present invention will be described with reference to Figures 6 and 7. Descriptions of the same configurations as those in the previously described embodiment will be omitted, and only other portions will be described.

[0044] FIG. 6 is an enlarged view of a portion corresponding to portion C in FIG. 4 in another embodiment of the present invention, and FIG. 7 is a cross-sectional view of a portion corresponding to portion B in FIG. 1 in another embodiment of the present invention.

[0045] 6, the upper cover 210 includes at least one first protrusion 212 protruding from a side surface of the upper cover 210 toward the case 300. The first protrusion 212 protrudes from the upper cover 210 and is formed to contact the inner surface of the case 300. As a result, a constant gap is maintained between the upper cover 210 and the case 300. At this time, in order to maintain the constant gap, the height (d) of the first protrusion 212 may be 1 mm or less.

[0046] 7, intermediate case 120 includes at least one second protrusion 121 protruding from an outer surface of intermediate case 120, i.e., a surface facing case 300, toward case 300. Second protrusion 121 protrudes from intermediate case 120 and is formed to contact an inner surface of case 300. As a result, a constant gap is maintained between intermediate case 120 and case 300, and the height of second protrusion 121 may be 1 mm or less.

[0047] In this way, the first protrusion 212 and the second protrusion 121 can maintain a constant gap between the battery cell assembly 100 and the case 300, and between the upper cover 210 and the case 300, and therefore the thermally conductive resin can be injected uniformly at these gaps, resulting in the formation of a heat transfer resin layer 400 of uniform thickness. Therefore, the heat dissipation effect of the heat transfer resin layer 400 can be achieved uniformly throughout.

[0048] Next, a battery module according to another embodiment of the present invention will be described with reference to Figures 8a and 8b. Descriptions of the same configurations as those in the previously described embodiment will be omitted, and only other portions will be described.

[0049] 8a and 8b are cross-sectional views of a portion corresponding to part B in FIG. 1 and part C in FIG. 4, respectively, in accordance with still another embodiment of the present invention.

[0050] 8a, the case 300 includes at least one third protrusion 301 protruding from the inner surface of the case 300 toward the intermediate case 120. The third protrusion 301 is formed to protrude from the inner surface of the case 300 and contact the intermediate case 120. Although not shown, the third protrusion 301 may also be formed at a portion where the inner surface of the case 300 faces the fixing resin layer 130. As a result, a constant gap is maintained between the battery cell assembly 100 and the case 300, and the height of the third protrusion 301 may be 1 mm or less.

[0051] 8b, the case 300 includes at least one fourth protrusion 302 protruding from the inner surface of the case 300 toward the upper cover 210. The fourth protrusion 302 protrudes from the inner surface of the case 300 and is formed to contact the upper cover 210. As a result, a constant distance is maintained between the upper cover 210 and the case 300, and the height of the fourth protrusion 302 may be 1 mm or less.

[0052] In this way, the third protrusion 301 and the fourth protrusion 302 can maintain a constant gap between the battery cell assembly 100 and the case 300, and between the upper cover 210 and the case 300, and therefore the thermally conductive resin can be poured uniformly at the gap, resulting in the formation of a heat transfer resin layer 400 of a uniform thickness. Therefore, the heat dissipation effect of the heat transfer resin layer 400 can be achieved uniformly throughout. In addition, the first protrusion 212 and the second protrusion 121, and the third protrusion 301 and the fourth protrusion 302 described above may both be provided, and their configurations are not particularly limited.

[0053] Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention. [Explanation of symbols]

[0054] 10: Battery module 100: Battery cell assembly 110: Cylindrical battery cell 120: Intermediate case 130: Fixed resin layer 210: Top cover 220: Lower cover 300: Case 400: Heat transfer resin layer 211: Resin injection hole 212: 1st protrusion 121:Second protrusion 301: Third protrusion 302: 4th protrusion

Claims

1. at least one battery cell assembly including a plurality of cylindrical battery cells arranged side-by-side; a case that houses the battery cell assembly; a fixing resin layer disposed on at least one of longitudinal ends of the cylindrical battery cells and fixing the cylindrical battery cells; a heat transfer resin layer formed between the fixing resin layer and the case and between a side surface of the battery cell assembly and the case, the heat transfer resin layer being in contact with the fixing resin layer and the case; A battery module comprising: The battery cell assembly further includes an intermediate case surrounding sides of the plurality of cylindrical battery cells.

2. The battery module according to claim 1 , wherein the heat transfer resin layer is also formed between the intermediate case and the case.

3. At least one battery cell assembly including a plurality of cylindrical battery cells arranged with their sides adjacent to each other; a case that houses the battery cell assembly; a fixing resin layer disposed on at least one of longitudinal ends of the cylindrical battery cells and fixing the cylindrical battery cells; a heat transfer resin layer formed between the fixing resin layer and the case and between a side surface of the battery cell assembly and the case, the heat transfer resin layer being in contact with the fixing resin layer and the case; A battery module comprising: The case has a tubular shape with an open upper and lower portion, and an upper cover and a lower cover are respectively coupled to the upper and lower portions.

4. The battery module according to claim 3 , wherein the upper cover includes a plurality of resin injection holes for injecting a heat transfer resin to form the heat transfer resin layer.

5. The battery module according to claim 4 , wherein the plurality of resin injection holes are formed adjacent to each other in the case.

6. The battery module of claim 3 , wherein the upper cover is inserted into and coupled to the inside of the case, and includes at least one first protrusion protruding from a side surface of the upper cover toward the case.

7. At least one battery cell assembly including a plurality of cylindrical battery cells arranged side-by-side; a case that houses the battery cell assembly; a fixing resin layer disposed on at least one of longitudinal ends of the cylindrical battery cells and fixing the cylindrical battery cells; a heat transfer resin layer formed between the fixing resin layer and the case and between a side surface of the battery cell assembly and the case, the heat transfer resin layer being in contact with the fixing resin layer and the case; A battery module comprising: The battery cell assembly further includes an intermediate case surrounding side surfaces of the cylindrical battery cells, The intermediate case includes at least one second protrusion protruding from an outer surface of the intermediate case toward the case.

8. At least one battery cell assembly including a plurality of cylindrical battery cells arranged side-by-side; a case that houses the battery cell assembly; a fixing resin layer disposed on at least one of longitudinal ends of the cylindrical battery cells and fixing the cylindrical battery cells; a heat transfer resin layer formed between the fixing resin layer and the case and between a side surface of the battery cell assembly and the case, the heat transfer resin layer being in contact with the fixing resin layer and the case; A battery module comprising: The battery cell assembly further includes an intermediate case surrounding side surfaces of the cylindrical battery cells, The case includes at least one third protrusion protruding from an inner surface of the case toward the intermediate case.

9. The upper cover is inserted into and coupled to the inside of the case, The battery module of claim 3 , wherein the case includes at least one fourth protrusion protruding from an inner surface of the case toward the upper cover.

10. A battery pack comprising at least one battery module described in any one of claims 1 to 9.

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