Battery pack, motor vehicle including the battery pack

Abstract

A battery pack according to an embodiment of the present invention includes a plurality of battery cells, a filling member filled in a space between the plurality of battery cells, and a bus bar assembly electrically connected to the plurality of battery cells and having a filling member injection hole formed therein for injecting the filling member.

Description

Technical Field

[0001] The present invention relates to a battery pack and an automobile including the battery pack. This application claims priority based on Korean Patent Application No. 10-2022-0087497 filed on July 15, 2022, and Korean Patent Application No. 10-2023-0091204 filed on July 13, 2023, and all of the contents disclosed in the specifications and drawings of the applications are incorporated into this application.

Background Art

[0002] Secondary batteries with high applicability for each product group and having electrical characteristics such as high energy density are generally applied not only to portable devices but also to electric vehicles (EVs) or hybrid electric vehicles (HEVs) driven by an electric drive source. Such secondary batteries are not only environmentally friendly because they have the primary advantage of significantly reducing the use of fossil fuels but also have the advantage of generating no by-products from energy use, and are attracting attention as a new energy source for improving energy efficiency.

[0003] Currently, secondary batteries such as lithium-ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel metal hydride batteries, and nickel zinc batteries are widely used. The operating voltage of such a unit secondary battery cell, that is, a unit battery cell, is about 2.5V to 4.5V. Therefore, when a higher output voltage is required, a plurality of battery cells are connected in series to form a battery pack. Also, depending on the charge and discharge capacity required for the battery pack, a plurality of battery cells may be connected in parallel to form a battery pack. Therefore, the number of battery cells included in the battery pack can be variously set according to the required output voltage or charge and discharge capacity.

[0004] On the one hand, when configuring a battery pack by connecting a plurality of battery cells in series or in parallel, it is common to first configure a battery module including at least one battery cell, and then add other components to such at least one battery module to form a battery pack or a battery rack.

[0005] In recent years, in battery packs, there has been an increasing demand for battery packs with a structure that can increase the energy density with a simpler structure, reduce the manufacturing cost and manufacturing time, and improve the manufacturing efficiency.

[0006] Therefore, there is a need for a solution to provide a battery pack that can increase the energy density with a simpler structure, reduce the manufacturing cost and manufacturing time, and improve the manufacturing efficiency, and a vehicle including the battery pack.

Summary of the Invention

Problems to be Solved by the Invention

[0007] Therefore, one aspect of the present invention aims to provide a battery pack that can increase the energy density with a simpler structure, and a vehicle including the battery pack.

[0008] Another aspect of the present invention aims to provide a battery pack that can reduce the manufacturing cost and manufacturing time and improve the manufacturing efficiency, and a vehicle including the battery pack.

Means for Solving the Problems

[0009] To achieve the above object, one aspect of the present invention provides a battery pack including a plurality of battery cells, a filling member filled in the space between the plurality of battery cells, and a busbar assembly electrically connected to the plurality of battery cells and having a filling member injection hole formed for injecting the filling member.

[0010] Also preferably, the bus bar assembly can be electrically connected to the positive and negative electrodes of the battery cell within the opening space of the filling member injection hole.

[0011] Also preferably, the opening space of the filling member injection hole can expose both the positive and negative electrodes of the battery cell.

[0012] Also preferably, the total area of the opening space can be larger than the flow area of the filling member that flows between the battery cells when the filling member is injected.

[0013] Also preferably, the filling member has a preset viscosity and can contain at least two substances.

[0014] Also preferably, the filling member can be a mixture of a predetermined resin and beads in a preset ratio.

[0015] Also preferably, the predetermined resin can include a silicone resin.

[0016] Also preferably, the predetermined beads can include glass bubbles.

[0017] Also preferably, the bus bar assembly is disposed on one side of a plurality of the battery cells, and includes a pair of bus bar covers in which the filling member injection holes are formed, and a sub-bus bar provided between the pair of bus bar covers and connected to the positive and negative electrodes of the battery cell.

[0018] Also preferably, the pair of bus bar covers can include a polyimide film.

[0019] Also preferably, the sub-bus bar is provided in a single layer and can be inserted between the pair of bus bar covers.

[0020] Further, preferably, the sub bus bar may include a bus bar bridge inserted between the pair of bus bar covers, a positive connection portion extending from the bus bar bridge, exposed within the opening space of the filling member injection hole, and connected to the positive electrode of the battery cell, and a negative connection portion extending from the bus bar bridge, exposed within the opening space of the filling member injection hole, and connected to the negative electrode of the battery cell.

[0021] Further, preferably, a plurality of the filling member injection holes are provided, and the plurality of filling member injection holes may include a positive electrode bus bar hole that exposes the positive connection portion and has an opening space larger than the size of the positive connection portion, and a negative electrode bus bar hole that exposes the negative connection portion and has an opening space larger than the size of the negative connection portion.

[0022] Further, preferably, a plurality of the filling member injection holes are provided, and each of the plurality of filling member injection holes may expose both the positive connection portion and the negative connection portion within one opening space.

[0023] Further, preferably, each of the plurality of filling member injection holes may have an opening space larger than the combined size of the positive connection portion and the negative connection portion.

[0024] Further, preferably, the positive electrode bus bar hole and the negative electrode bus bar hole may be arranged to face each other with the bus bar bridge interposed therebetween.

[0025] Also, one aspect of the present invention provides a method for manufacturing a battery pack, including arranging a cooling unit between a plurality of battery cells, aligning the battery cells and the cooling unit using a side structure unit so that they can be accommodated, electrically connecting the battery cells within the opening space of the filling member injection hole of a bus bar assembly having a filling member injection hole from above the plurality of battery cells, and injecting and applying a filling member from above to below the battery cells along the vertical direction of the battery cells through the opening space of the filling member injection hole.

[0026] Also, preferably, the filling member may be a mixture of a predetermined resin and beads at a preset ratio.

[0027] Also, preferably, the mixing ratio of the predetermined resin and beads may be 100:60 (resin: glass bubbles).

[0028] Also, one aspect of the present invention provides an automobile including at least one of the battery packs described above.

Advantages of the Invention

[0029] According to one aspect of the present invention, it is possible to provide a battery pack capable of increasing the energy density with a simpler structure, and an automobile including the battery pack.

[0030] Also, according to one aspect of the present invention, it is possible to provide a battery pack capable of reducing the manufacturing cost and manufacturing time and improving the manufacturing efficiency, and an automobile including the battery pack.

[0031] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further understand the technical idea of the present invention together with the detailed description of the invention. Therefore, the present invention is not to be construed as being limited only to the matters described in the drawings.

Brief Description of the Drawings

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Mode for Carrying Out the Invention

[0033] Hereinafter, the present invention will be made clearer by explaining preferred embodiments of the present invention in detail with reference to the attached drawings. The embodiments described below are shown exemplarily to assist in understanding the invention, and it must be understood that the present invention can be variously modified and implemented from the embodiments described below. Also, for the purpose of assisting in understanding the invention, the attached drawings may show the dimensions of some components exaggerated, not at actual scale.

[0034] FIG. 1 is a diagram for explaining a battery pack according to an embodiment of the present invention, and FIG. 2 is an exploded perspective view of the battery pack of FIG. 1.

[0035] Referring to FIGS. 1 and 2, the battery pack 1 may be provided in an electric vehicle or a hybrid vehicle as an energy source. Hereinafter, the battery pack 1 provided in such an electric vehicle or the like will be described in more detail with reference to the related drawings.

[0036] The battery pack 1 may include a plurality of battery cells 100, a bus bar assembly 200, and a filling member 500.

[0037] The plurality of battery cells 100 are secondary batteries, which can be cylindrical secondary batteries, pouch-type secondary batteries, or rectangular secondary batteries. Hereinafter, in the present embodiment, the description will be limited to the case where the plurality of battery cells 100 are cylindrical secondary batteries. Hereinafter, each battery cell 100 will be described in more detail with reference to the related drawings.

[0038] The filling member 500 can be filled in the space between the plurality of battery cells 100. Here, the filling member 500 is a potting resin and can be provided by being mixed with beads such as glass bubbles. Details of the filling member 500 will be described later.

[0039] The bus bar assembly 200 can be electrically connected to the plurality of battery cells 100. Filling member injection holes 242 and 244 for injecting the filling member 500 can be formed in the bus bar assembly 200.

[0040] According to the present embodiment, by directly and quickly injecting the filling member 500 through the filling member injection holes 242 and 244 provided in the bus bar assembly 200 into the space between the battery cells 100, the process time can be shortened during the injection process for injecting the filling member 500, and the process efficiency can be significantly improved.

[0041] Also, the bus bar assembly 200 can be electrically connected to the positive electrode 40 and the negative electrode 20a of the battery cell 100 within the opening space of the filling member injection holes 242 and 244.

[0042] According to the present embodiment, since both the injection of the filling member 500 and the electrical connection of the battery cells 100 can be realized through the filling member injection holes 242 and 244, a bus bar assembly 200 with a simpler structure can be provided to simplify the structure of the entire battery pack and further improve the manufacturing efficiency.

[0043] Hereinafter, the battery pack 1 according to such an embodiment will be described in more detail.

[0044] Referring to FIGS. 3 to 7, the battery cell 100 includes an electrode assembly 10, a battery can 20, a cap plate 30, and a first electrode terminal (positive electrode) 40. In addition to the above-described components, the battery cell 100 may further include an insulating gasket 50 and / or an upper current collector plate 60 and / or an insulating plate 70 and / or a lower current collector plate 80 and / or a sealing gasket 90.

[0045] The electrode assembly 10 includes a first electrode plate having a first polarity, a second electrode plate having a second polarity, and a separator interposed between the first electrode plate and the second electrode plate. The first electrode plate is a positive electrode plate or a negative electrode plate, and the second electrode plate corresponds to an electrode plate having a polarity opposite to that of the first electrode plate.

[0046] The electrode assembly 10 may be, for example, in a jelly-roll shape. That is, the electrode assembly 10 can be manufactured by winding a laminate formed by sequentially laminating at least once a first electrode plate, a separator, and a second electrode plate around a winding center C. In this case, a separator may be provided on the outer peripheral surface of the electrode assembly 10 for insulation from the battery can 20.

[0047] The first electrode plate includes a first electrode current collector and a first electrode active material applied on one or both surfaces of the first electrode current collector. There is a plain portion on one side end of the first electrode current collector in the width direction (Z-axis direction) where the first electrode active material is not applied. The plain portion functions as a first electrode tab. The first electrode tab 11 is provided at the upper part in the height direction (Z-axis direction) of the electrode assembly 10 housed in the battery can 20.

[0048] The second electrode plate includes a second current collector and a second electrode active material coated on one or both surfaces of the second current collector. There is a plain portion on the other end of the second current collector in the width direction (Z-axis direction) where the second electrode active material is not coated. The plain portion functions as the second electrode tab 12. The second electrode tab 12 is provided at the lower part of the electrode assembly 10 accommodated in the battery can 20 in the height direction (Z-axis direction).

[0049] The battery can 20 is a cylindrical container with an opening formed at the bottom, and includes a metallic material having conductivity. The side surface and the upper surface of the battery can 20 are integrally formed. The upper surface of the battery can 20 has a substantially flat shape. The battery can 20 accommodates the electrode assembly 10 through the opening formed at the bottom, and also accommodates the electrolyte together.

[0050] The battery can 20 is electrically connected to the second electrode tab 12 of the electrode assembly 10. Therefore, the battery can 20 has the same polarity as the second electrode tab 12.

[0051] The battery can 20 may include a beading portion 21 formed at its lower end and a crimping portion 22. The beading portion 21 is formed at the lower part of the electrode assembly 10. The beading portion 21 is formed by pushing in the outer peripheral surface of the battery can 20. The beading portion 21 can prevent the electrode assembly 10 having a size corresponding to the width of the battery can 20 from coming out of the opening formed at the lower end of the battery can 20, and can function as a support portion on which the cap plate 30 is placed.

[0052] The crimping portion 22 is formed at the lower part of the beading portion 21. The crimping portion 22 has a form that extends and is bent so as to surround the outer peripheral surface of the cap plate 30 disposed below the beading portion 21 and a part of the lower surface of the cap plate 30.

[0053] The cap plate 30 is a component containing a metal material having conductivity, and covers the opening formed at the lower end of the battery can 20. That is, the cap plate 30 constitutes the lower surface of the battery cell 100. The cap plate 30 is placed on the beading portion 21 formed on the battery can 20 and fixed by the crimping portion 22. A sealing airtight gasket 90 may be interposed between the cap plate 30 and the crimping portion 22 of the battery can 20 to ensure the airtightness of the battery can 20.

[0054] The cap plate 30 may further include a vent portion 31 formed to prevent an increase in internal pressure due to gas generated inside the battery can 20. The vent portion 31 corresponds to a region of the cap plate 30 that is thinner than the peripheral region. The vent portion 31 is structurally weaker compared to the peripheral region. For this reason, when an abnormality occurs in the battery cell 100 and the internal pressure increases above a certain level, the vent portion 31 breaks and the gas generated inside the battery can 20 is discharged.

[0055] Holes may be formed in advance on the upper surface of the battery can 20 before arranging the first electrode terminal 40 and the insulating gasket 50, but it is not limited thereto, and the holes may be formed by other methods. For example, a hole may be formed while inserting the first electrode terminal 40, holes having different diameters may be formed in advance, or the upper surface may be cut out or the first electrode terminal 40 may be inserted into the pre-cut upper surface. That is, the hole may be expanded to a desired size, or after cutting out to form a small hole, it may be expanded to a desired size. Furthermore, it goes without saying that other methods of forming holes are available.

[0056] The battery cell 100 according to an embodiment of the present invention has a structure in which all the positive and negative electrode terminals are present at the upper part, and thus the upper structure is more complex than the lower structure. For this reason, a vent portion 31 may be formed in the cap plate 30 forming the lower surface of the battery cell 100 to smoothly discharge the gas generated inside the battery can 20.

[0057] The vent portion 31 can be continuously formed while drawing a circle on the cap plate 30. However, it is not limited thereto, and the vent portion 31 may be discontinuously formed while drawing a circle on the cap plate 30, or may be formed in a linear shape or other shape.

[0058] The first electrode terminal 40 includes a conductive metal material and is electrically connected to the first electrode tab 11 of the electrode assembly 10 through the upper surface of the battery can 20. Therefore, the first electrode terminal 40 has a first polarity. The first electrode terminal 40 is electrically insulated from the battery can 20 having a second polarity.

[0059] The first electrode terminal 40 includes an exposed terminal portion 41 and an insertion terminal portion 42. The exposed terminal portion 41 is exposed outside the battery can 20. The exposed terminal portion 41 is located at the center of the upper surface of the battery can 20. The insertion terminal portion 42 penetrates the center of the upper surface of the battery can 20 and is electrically connected to the first electrode tab 11. The insertion terminal portion 42 can be rivet-bonded to the inner surface of the battery can 20.

[0060] The upper surface of the battery can 20 and the first electrode terminal 40 have opposite polarities and face the same direction. Also, a step may be formed between the first electrode terminal 40 and the upper surface of the battery can 20. Specifically, when the entire upper surface of the battery can 20 has a flat shape or a shape protruding upward at its center, the exposed terminal portion 41 of the first electrode terminal 40 can protrude further above the upper surface of the battery can 20. Conversely, when the upper surface of the battery can 20 is concave with a downward, i.e., toward the electrode assembly 10, at its center, the upper surface of the battery can 20 can protrude further above the exposed terminal portion 41 of the first electrode terminal 40.

[0061] The insulating gasket 50 is interposed between the battery can 20 and the first electrode terminal 40 to prevent the battery can 20 and the first electrode terminal 40 having opposite polarities from contacting each other. Thereby, the upper surface of the battery can 20 having a substantially flat shape can function as the second electrode terminal of the battery cell 100.

[0062] The insulating gasket 50 includes an exposed portion 51 and an insertion portion 52. The exposed portion 51 is interposed between the exposed terminal portion 41 of the first electrode terminal 40 and the battery can 20. The insertion portion 52 is interposed between the insertion terminal portion 42 of the first electrode terminal 40 and the battery can 20. The insulating gasket 50 may include, for example, a resin material having insulating properties.

[0063] When the insulating gasket 50 includes a resin material, the insulating gasket 50 can be coupled to the battery can 20 and the first electrode terminal 40, for example, by heat fusion. In this case, the airtightness at the bonding interface between the insulating gasket 50 and the first electrode terminal 40 and at the bonding interface between the insulating gasket 50 and the battery can 20 can be enhanced.

[0064] Of the upper surface of the battery can 20, the entire remaining region excluding the region occupied by the first electrode terminal 40 and the insulating gasket 50 corresponds to a second electrode terminal (negative electrode) 20a having a polarity opposite to that of the first electrode terminal 40.

[0065] The battery cell 100 according to an embodiment of the present invention includes, on one side in its longitudinal direction (Z-axis direction), a first electrode terminal 40 having a first polarity and a second electrode terminal 20a that is electrically insulated from the first electrode terminal 40 and has a second polarity. That is, in the battery cell 100 according to an embodiment of the present invention, since a pair of electrode terminals (the first electrode terminal 40 and the second electrode terminal 20a) are located in the same direction, when a plurality of battery cells 100 are electrically connected, electrical connection components such as a bus bar assembly 200 described later can be arranged only on one side of the battery cell 100. This can simplify the structure of the battery pack 1 and improve the energy density.

[0066] Hereinafter, the bus bar assembly 200 for such electrical connection with a plurality of battery cells 100 will be described more specifically.

[0067] Referring further to FIG. 2, the bus bar assembly 200 is provided on one side of the battery cell 100, specifically, on the upper side (+Z-axis direction) of the battery cell 100, and can be electrically connected to a plurality of the battery cells 100. The electrical connection of the bus bar assembly 200 can be in parallel and / or series connection.

[0068] Such a bus bar assembly 200 is electrically connected to a first electrode terminal 40 (see FIG. 3) having a first polarity of a plurality of the battery cells 100 and a second electrode terminal 20a (see FIG. 3) of a battery can 20 having a second polarity, and can be electrically connected to an external charge / discharge line or the like through a connector terminal 290 or the like. Here, the first polarity can be the positive electrode and the second polarity can be the negative electrode.

[0069] Hereinafter, the configuration of the bus bar assembly 200 will be described in more detail.

[0070] FIG. 8 is a diagram for explaining the bus bar assembly of the battery pack shown in FIG. 2, FIG. 9 is a diagram for explaining the connecting bus bar unit of the bus bar assembly shown in FIG. 8, FIG. 10 is an exploded perspective view of the connecting bus bar unit of FIG. 9, FIG. 11 is an enlarged view for explaining a main part of the connecting bus bar unit of FIG. 9, and FIG. 12 is a diagram for explaining the structure of an injection hole of a filling member according to another embodiment of the connecting bus bar unit of FIG. 11.

[0071] Referring further to FIGS. 8 to 11 and FIG. 2, the bus bar assembly 200 can include a main bus bar unit 210, a connecting bus bar unit 230, an interconnection board 260, and a connector terminal 290.

[0072] A plurality of the main bus bar units 210 are provided and can be electrically connected to the battery cells 100 arranged on the outermost periphery in the longitudinal direction (Y-axis direction) of the battery pack 1. Such a main bus bar unit 210 can be electrically connected to a connector terminal 290 described later.

[0073] The connection bus bar unit 230 is disposed between the main bus bar units 210 in the longitudinal direction (Y-axis direction) of the battery pack 1, is electrically connected to the plurality of battery cells 100, and can cover the plurality of battery cells 100.

[0074] The connection bus bar unit 230 may be provided with one or a plurality of units in a size that can cover all of the plurality of battery cells 100 and can cover the plurality of battery cells 100. Hereinafter, in the present embodiment, the description will be made by limiting the connection bus bar unit 230 to be provided with a plurality of units.

[0075] Each of such a plurality of connection bus bar units 230 may include a bus bar cover 240 and a sub-bus bar 250.

[0076] The bus bar cover 240 covers the upper side of the plurality of battery cells 100 and may be configured in a substantially flat plate shape. The shape and size of the bus bar cover 240 may vary according to the number and capacity of the battery cells 100 required by the battery pack 1.

[0077] The bus bar cover 240 may include an insulating material. For example, the bus bar cover 240 may include a polyimide film. However, it is not limited thereto, and it goes without saying that the bus bar cover 240 may include other insulating members made of an insulating material.

[0078] Such a pair of bus bar covers 240 are provided in a pair so as to have corresponding shapes and sizes in the vertical direction (Z-axis direction) of the battery pack 1 and can be coupled to each other. Here, the sub-bus bar 250 described later is a single layer and can be inserted and provided between the pair of bus bar covers 240.

[0079] Such a pair of bus bar covers 240 may include a positive electrode bus bar hole 242, a negative electrode bus bar hole 244, and a guide hole 246.

[0080] The positive electrode bus bar holes 242 and the negative electrode bus bar holes 244 may be the above-described filling member injection holes 242, 244. That is, the filling member injection holes 242, 244 can also serve to guide the connection with the positive electrode 40 and the negative electrode 20a of the battery cell 100. That is, the filling member injection holes 242, 244 may be formed in a pair of bus bar covers 240.

[0081] Specifically, a plurality of the filling member injection holes 242, 244 may be provided.

[0082] The plurality of filling member injection holes 242, 244 may include a positive electrode bus bar hole 242 that exposes a positive electrode connection portion 254 described later and has an opening space larger than the size of the positive electrode connection portion 254, and a negative electrode bus bar hole 244 that exposes a negative electrode connection portion 256 described later and has an opening space larger than the size of the negative electrode connection portion 256. Here, the positive electrode bus bar hole 242 and the negative electrode bus bar hole 244 may be disposed opposite to each other with a bus bar bridge 252 described later interposed therebetween.

[0083] Hereinafter, the positive electrode bus bar hole 242 and the negative electrode bus bar hole 244 that constitute the filling member injection holes 242, 244 will be described in more detail.

[0084] The positive electrode bus bar hole 242 has an opening space of a predetermined size and may be provided in plurality. The positive electrode connection portion 254 described later may be exposed in such positive electrode bus bar holes 242. Here, the positive electrode bus bar hole 242 may be formed to have an opening space larger than the size of the positive electrode connection portion 254 described later in order to improve the process workability and the injection efficiency of a filling member 500 described later.

[0085] The positive electrode bus bar hole 242 can more efficiently guide the electrical connection between the positive electrode connection portion 254 described later and the first electrode terminal 40 (see FIG. 3), which is the positive electrode of the battery cell 100.

[0086] Furthermore, when injecting the filling member 500 described below through the opening space of the positive electrode bus bar hole 242, the injection efficiency of the filling member 500 can be significantly increased. Specifically, through the opening space of the positive electrode bus bar hole 242, the filling member 500 provided as the potting resin described below can be injected more directly in the vertical direction (Z-axis direction) from the upper side to the lower side of the battery pack 1, so that the injection efficiency between the battery cells 100 can be significantly improved.

[0087] The negative electrode bus bar holes 244 are arranged to face the positive electrode bus bar holes 242, have an opening space of a predetermined size like the positive electrode bus bar holes 242, and a plurality of them may be provided. Here, the negative electrode bus bar holes 244 may be formed to have an opening space larger than the size of the negative electrode connection part 256 described below in order to improve the process workability and the injection efficiency of the filling member 500 described below.

[0088] The negative electrode bus bar holes 244 can more efficiently guide the electrical connection between the negative electrode connection part 256 described below and the battery can 20 (see FIG. 3), which is the negative electrode of the battery cell 100, specifically, the second electrode terminal 20a.

[0089] Furthermore, when injecting the filling member 500 described below through the opening space of the negative electrode bus bar hole 244, the injection efficiency of the filling member 500 can be significantly increased. Specifically, through the opening space of the negative electrode bus bar hole 244, the filling member 500 provided as the potting resin described below can be injected more directly in the vertical direction (Z-axis direction) from the upper side to the lower side of the battery pack 1, so that the injection efficiency between the battery cells 100 can be significantly improved.

[0090] On the one hand, the opening space of the positive electrode bus bar hole 242 and the opening space of the negative electrode bus bar hole 244, that is, the total area of the opening spaces of the filling member injection holes 242 and 244, can be larger than the flow area of the filling member 500 flowing between the battery cells 100 during the injection of the filling member 500. This is to prevent a delay in the injection of the filling member 500 and thus prevent a delay from occurring in the overall injection process.

[0091] On the other hand, referring to FIG. 12, the opening space of the filling member injection hole 243 may expose both the positive electrode 40 (see FIG. 3) and the negative electrode 20 (see FIG. 3) of the battery cell 100. Specifically, each of the plurality of filling member injection holes 243 can expose both the positive electrode connection part 254 and the negative electrode connection part 256, which will be described later, within one opening space. Thereby, within the opening space of each of the filling member injection holes 243, the positive electrode 40 (see FIG. 3) and the negative electrode 20 (see FIG. 3) of the battery cell 100 can be connected to the positive electrode connection part 254 and the negative electrode connection part 256, which will be described later.

[0092] According to such an embodiment of the present invention, since the electrical connection between the positive electrode 40 (see FIG. 3) and the negative electrode 20 (see FIG. 3) of the battery cell 100 and the positive electrode connection part 254 and the negative electrode connection part 256, which will be described later, can be realized within one opening space of the filling member injection hole 243, the process of forming the filling member injection holes 243 in the pair of bus bar covers 240 is further simplified.

[0093] And each of the plurality of filling member injection holes 243 can have an opening space larger than the combined size of the positive electrode connection part 254 and the negative electrode connection part 256, which will be described later. Therefore, the process convenience for the electrical connection work within the opening space can be further ensured. Also, the injection efficiency of the filling member 500 from the filling member injection holes 243 can be improved.

[0094] Referring further to FIGS. 8 to 11 and FIG. 2 described above, the guide holes 246 can guide the assembly position of the busbar assembly 200. Specifically, the guide holes 246 can fix the connection busbar unit 230 to the side structure unit 400 and guide the accurate arrangement of the connection busbar unit 230.

[0095] A plurality of the guide holes 246 may be provided. The busbar guide protrusions 416 of the side structure unit 400 described later can be inserted into the plurality of guide holes 246.

[0096] The sub-busbar 250 is for electrical connection with the first electrode terminal 40 which is the positive electrode of the plurality of battery cells 100 and the second electrode terminal 20a which is the negative electrode, and can be provided on the upper side of the busbar cover 240 or inserted into a pair of busbar covers 240. Hereinafter, in this embodiment, the description will be limited to being inserted into or coupled to the busbar cover 240.

[0097] Such a sub-busbar 250 may include a busbar bridge 252, a positive connection portion 254, and a negative connection portion 256.

[0098] The busbar bridge 252 is inserted into a pair of the busbar covers 240 and can be formed with a predetermined length along the width direction (X-axis direction) of the battery pack 1. Such a busbar bridge 252 can be configured in a shape corresponding to the arrangement structure of the battery cells 100 in the width direction (X-axis direction) of the battery pack 1 so as to improve the electrical connection efficiency with the battery cells 100. Accordingly, in this embodiment, the busbar bridge 252 can be arranged in a zigzag shape in the width direction (X-axis direction) of the battery pack 1.

[0099] A plurality of such busbar bridges 252 may be provided. The plurality of busbar bridges 252 are inserted into the busbar cover 240 and can be arranged at a predetermined distance apart in the longitudinal direction (Y-axis direction) of the battery pack 1.

[0100] The bus bar bridge 252 may include a conductive material. For example, the bus bar bridge 252 may include an aluminum or copper material as a metal material. However, it is not limited thereto, and it goes without saying that the bus bar bridge 252 may include other materials for electrical connection.

[0101] The positive electrode connection portion 254 may integrally extend and protrude from the bus bar bridge 252 and may be disposed within the positive electrode bus bar hole 242. Specifically, the positive electrode connection portion 254 may be exposed within the opening space of the positive electrode bus bar hole 242, that is, the filling member injection hole 242.

[0102] Such a positive electrode connection portion 254 may be electrically connected to the first electrode terminal 40 (see FIG. 3), which is the positive electrode of the battery cell 100. The electrical connection may be made through a welding process for electrical connection such as laser welding or ultrasonic welding.

[0103] Since the connection between the positive electrode connection portion 254 and the positive electrode (first electrode terminal 40) of the battery cell 100 is made in the opening space of the positive electrode bus bar hole 242, the welding process for the connection can be immediately performed in the opening space without a separate additional process during the connection.

[0104] The negative electrode connection portion 256 may integrally extend from the bus bar bridge 252 and protrude in the direction opposite to that of the positive electrode connection portion 254 and may be disposed within the negative electrode bus bar hole 244. Specifically, the negative electrode connection portion 256 may be exposed within the opening space of the negative electrode bus bar hole 244, that is, the filling member injection hole 244.

[0105] Such a negative electrode connection portion 256 may be electrically connected to the second electrode terminal 20a (see FIG. 3), which is the negative electrode of the battery cell 100. The electrical connection may be made through a welding process for electrical connection such as laser welding or ultrasonic welding.

[0106] Since the connection between the negative electrode connection part 256 and the negative electrode (second electrode terminal 20a) of the battery cell 100 is made in the opening space of the negative electrode bus bar hole 244, when connecting, a welding process or the like for the connection can be immediately performed in the opening space without a separate additional process.

[0107] The interconnection board 260 can be connected to the external sensing line and provided at one end (-Y-axis direction) of the battery pack 1. The position of the interconnection board 260 can be changed by design or the like, and it may be provided at other positions where it can be connected to the external sensing line. Further, a plurality of interconnection boards 260 may be provided according to the number and capacity of the battery cells 100 of the battery pack 1.

[0108] Such an interconnection board 260 can be provided so as to be exposed outside the battery pack 1 for connection to the external sensing line. The external sensing line can connect the interconnection board 260 and a battery management system (not shown). The battery management system can determine the charge state of the battery cells connected in parallel based on the voltage of the battery cells connected in parallel.

[0109] A thermistor for checking the temperature state of the battery cell 100 can be provided on the interconnection board 260. Such a thermistor can be built into the interconnection board 260 or separately attached outside the interconnection board 260. The connector terminals 290 can be provided in a pair. Such a pair of connector terminals 290 is for connection to an external charge and discharge line and can be configured as high-voltage connector terminals.

[0110] Referring further to FIG. 2, the battery pack 1 may include a cooling unit 300.

[0111] The cooling unit 300 is for cooling the battery cell 100, is disposed below the bus bar assembly 200 (in the -Z axis direction), and can be disposed between a plurality of the battery cells 100 along the longitudinal direction (Y axis direction) of the battery pack 1.

[0112] A plurality of such cooling units 300 can be provided.

[0113] A plurality of the cooling units 300 can be disposed so as to face a plurality of the battery cells 100 in the width direction (X axis direction) of the battery pack 1. Here, a plurality of the cooling units 300 can be disposed so as to contact the opposing battery cells 100 in order to enhance the cooling performance.

[0114] Hereinafter, such a cooling unit 300 will be described in more detail.

[0115] FIG. 13 is a diagram for explaining the cooling unit of the battery pack shown in FIG. 2, FIG. 14 is an exploded perspective view of the cooling unit of FIG. 13, and FIG. 15 is a cross-sectional view of the cooling unit of FIG. 13.

[0116] Referring further to FIGS. 13 to 15 and FIG. 2, the cooling unit 300 may include a cooling tube 310, a cooling flow path 350, and a cooling fluid inlet / outlet portion 370.

[0117] The cooling tube 310 is formed with a predetermined length along the longitudinal direction (Y axis direction) of the battery pack 1, is disposed between a plurality of the battery cells 100, and a cooling flow path 350 for circulation of a cooling fluid described later can be provided inside. In the present embodiment, the cooling fluid can be water, but may include not only water but also one or more fluids capable of exchanging heat with the surrounding environment.

[0118] The cooling tube 310 can be formed in a shape corresponding to the outer surfaces of a plurality of opposing battery cells 100 in the width direction (X axis direction) of the battery pack 1.

[0119] Such a cooling tube 310 may be formed such that a plurality of convex portions 312 and concave portions 316 formed in a concavo-convex shape in the width direction (X-axis direction) of the battery pack 1 are alternately arranged along the longitudinal direction (Y-axis direction) of the battery pack 1.

[0120] The cooling tube 310 may be arranged to contact the outer surfaces of the plurality of battery cells 100 in order to further enhance the cooling performance of the battery cells 100. Such a cooling tube 310 may be adhesively fixed to the plurality of battery cells 100 through a filling member 500 or a separate adhesive member described later.

[0121] At one end (-Y-axis direction) of the cooling tube 310, a cooling fluid guide portion 318 for guiding the cooling fluid into the cooling flow path 350 described later may be provided. The cooling fluid guide portion 318 is formed at one end (-Y-axis direction) in the longitudinal direction (Y-axis direction) of the cooling tube 310 and may be provided in a pair. One of the pair of cooling fluid guide portions 318 may communicate with the upper flow path 352 of the cooling flow path 350 described later, and the other of the pair of cooling fluid guide portions 318 may communicate with the lower flow path 354 of the cooling flow path 350 described later. Specifically, one of the pair of cooling fluid guide portions 318 is provided on the upper side (+Z-axis direction) in the height direction (Z-axis direction) of the cooling tube 310 so as to communicate with the upper flow path 352 described later, and the other of the pair of cooling fluid guide portions 318 may be provided on the lower side (-Z-axis direction) in the height direction (Z-axis direction) of the cooling tube 310 so as to communicate with the lower flow path 354 described later.

[0122] The cooling flow path 350 circulates the cooling fluid for cooling the battery cells 100, is provided in the cooling tube 310, and may be connected so as to communicate with a cooling fluid inlet / outlet portion 370 described later.

[0123] Such a cooling flow path 350 may include an upper flow path 352, a lower flow path 354, and a connecting flow path 356.

[0124] The upper flow path 352 is disposed above the cooling tube 310 so as to be provided near the bus bar assembly 200, and may be formed with a predetermined length along the longitudinal direction (Y-axis direction) of the cooling tube 310. Such an upper flow path 352 may be connected so as to communicate with the cooling fluid supply port 374 of the cooling fluid inflow / outflow unit 370.

[0125] At least one upper flow path 352 may be provided. Hereinafter, in this embodiment, for the sake of ensuring cooling performance, the description will be limited to the case where a plurality of upper flow paths 352 are provided.

[0126] The lower flow path 354 is disposed below the cooling tube 310 (-Z-axis direction) at a distance from at least one upper flow path 352, and may be formed with a predetermined length along the longitudinal direction (Y-axis direction) of the cooling tube 310. Such a lower flow path 354 may be connected so as to communicate with the cooling fluid discharge port 376 of the cooling fluid inflow / outflow unit 370.

[0127] At least one lower flow path 354 may be provided. Hereinafter, in this embodiment, for the sake of ensuring cooling performance, the description will be limited to the case where a plurality of lower flow paths 354 are provided.

[0128] The connecting flow path 356 may connect at least one upper flow path, in this embodiment, a plurality of upper flow paths 352 and at least one lower flow path, in this embodiment, a plurality of lower flow paths 354.

[0129] The connecting flow path 356 may be provided at the other end (+Y-axis direction) of the cooling tube 310, which is on the opposite side of the cooling fluid inflow / outflow unit 370, so as to ensure the cooling flow path 350 to the maximum extent.

[0130] In the case of this embodiment, when the cooling fluid circulates in the cooling channel 350, the cooling fluid supplied from the cooling fluid supply port 374 is first supplied to the upper channel 352 disposed near the bus bar assembly 200, and then flows toward the cooling fluid discharge port 376 side through the connecting channel 356 and the lower channel 354.

[0131] Thus, in this embodiment, since the cold cooling fluid is preferentially supplied to the vicinity of the bus bar assembly 200 having a relatively high temperature distribution in the battery pack 1, the cooling performance of the battery cell 100 can be significantly improved.

[0132] The cooling fluid inlet / outlet portion 370 can be connected to the cooling tube 310 so as to communicate with the cooling channel 350 of the cooling tube 310. Such a cooling fluid inlet / outlet portion 370 can be exposed outside the side surface structure unit 400 described later and connected so as to communicate with an external cooling line.

[0133] The cooling fluid inlet / outlet portion 370 can be provided on one side surface (-Y-axis direction) in the longitudinal direction (Y-axis direction) of the battery pack 1. The cooling tube 310 connected to the cooling fluid inlet / outlet portion 370 can be formed with a predetermined length from the cooling fluid inlet / outlet portion 370 toward the other side surface (+Y-axis direction) of the battery pack 1 in the longitudinal direction (Y-axis direction) of the battery pack 1.

[0134] The cooling fluid inlet / outlet portion 370 may include an inlet / outlet body (supply port body 371, discharge port body 372), a cooling fluid supply port 374, and a cooling fluid discharge port 376.

[0135] The inlet / outlet body (supply port body 371, discharge port body 372) can be connected to one end portion (-Y-axis direction) of the cooling tube 310. Such an inlet / outlet body may include a supply port body 371 and a discharge port body 372.

[0136] The supply port body 371 covers one end (-Y-axis direction) of the cooling tube 310 and can be coupled to a discharge port body 372 described later. In such a supply port body 371, a supply port through-hole 371a through which a cooling fluid supply port 374 described later penetrates may be formed. The cooling fluid supply port 374 described later can communicate with an upper flow path 352 described later through the supply port through-hole 371a and via the cooling fluid guide portion 318. Specifically, the cooling fluid supply port 374 described later can communicate with the upper flow path 352 described later through the cooling fluid guide portion 318 located on the upper side (+Z-axis direction) of the cooling fluid guide portion 318 of the cooling tube 310.

[0137] The discharge port body 372 is coupled to the supply port body 371 on the opposite side of the supply port body 371 with one end (-Y-axis direction) of the cooling tube 310 interposed therebetween, and can cover one end (-Y-axis direction) of the cooling tube 310. Here, the discharge port body 372 and the supply port body 371 can be assembled to each other by press hemming.

[0138] In such a discharge port body 372, a discharge port through-hole 372a through which a cooling fluid discharge port 376 described later penetrates may be formed. The cooling fluid discharge port 376 described later can communicate with a lower flow path 354 described later through the discharge port through-hole 372a and via the cooling fluid guide portion 318. Specifically, the cooling fluid discharge port 376 described later can communicate with the lower flow path 354 described later through the cooling fluid guide portion 318 located on the lower side (-Z-axis direction) of the cooling fluid guide portion 318 of the cooling tube 310.

[0139] The cooling fluid supply port 374 is provided in the supply port body 371 of the inflow / outflow unit body (supply port body 371, discharge port body 372), and can be connected so as to communicate with the upper flow path 352. Here, the cooling fluid supply port 374 can be caulked and coupled to the supply port body 371. Such a cooling fluid supply port 374 can be connected so as to communicate with the external cooling line.

[0140] The cooling fluid discharge port 376 is provided in the discharge port body 372 of the inflow / outflow unit body (supply port body 371, discharge port body 372), and can be connected so as to communicate with the lower flow path 354. Here, the cooling fluid discharge port 376 can be caulked and coupled to the discharge port body 372. Such a cooling fluid discharge port 376 is arranged at a predetermined distance from the cooling fluid supply port 374 and can be connected so as to communicate with the external cooling line.

[0141] Referring further to FIG. 2, the battery pack 1 may include a side structure unit 400.

[0142] The side structure unit 400 includes a plastic resin material, supports the battery cell 100, ensures the rigidity of the battery cell 100, and can form the side appearance of the battery pack 1.

[0143] Hereinafter, the side structure unit 400 will be described more specifically with reference to the related drawings.

[0144] FIG. 16 is a diagram for explaining the side structure unit shown in FIG. 2, and FIG. 17 is a diagram for explaining the main plate of the side structure unit of FIG. 16.

[0145] Referring to FIGS. 16 and 17, the side structure unit 400 supports the battery cell 100, and while ensuring the rigidity of the battery cell 100, functions as a pack case that forms the outer surface of the battery pack 1 (see FIG. 2) and forms the appearance of the battery pack 1 (see FIG. 2).

[0146] Such a side structure unit 400 is formed with a predetermined length along the longitudinal direction (Y-axis direction) of the battery pack 1, and can accommodate and support the battery cell 100.

[0147] The side structure unit 400 may include a main plate 410 and an end plate 450.

[0148] The main plate 410 is formed with a predetermined length along the longitudinal direction (Y-axis direction) of the battery pack 1, and can accommodate the battery cells 100 so as to be arranged in two rows along the width direction (X-axis direction) of the battery pack 1. A plurality of such main plates 410 may be provided and arranged at a predetermined distance from each other along the width direction (X-axis direction) of the battery pack 1.

[0149] Such a plurality of main plates 410 ensure the rigidity of the battery cell 100 and the cooling unit 300, and at the same time, occupy a predetermined space within the battery pack 1 (see FIG. 2), thereby reducing the injection amount of the filling member 500 described later. In the case of the filling member 500 containing a silicone resin described later, since it is relatively expensive, by reducing the injection amount of the silicone resin through the plurality of main plates 410, the price competitiveness during the manufacture of the battery pack 1 can be further ensured.

[0150] Each of the plurality of main plates 410 may include a first cell accommodating portion 411, a second cell accommodating portion 412, an inter-wing 413, a bottom rib 415, a bus bar guide protrusion 416, a cooling unit insertion groove 417, and a guide step 418.

[0151] The first cell accommodating portion 411 may be provided in front of the main plate 410 (+X-axis direction) along the longitudinal direction (Y-axis direction) of the main plate 410. Such a first cell accommodating portion 411 may accommodate a plurality of the battery cells 100 arranged in the longitudinal direction (Y-axis direction) of the battery pack 1. Therefore, a plurality of the first cell accommodating portions 411 may be provided in front of the main plate 410 (+X-axis direction).

[0152] Each of the plurality of the first cell accommodating portions 411 is configured in a concave shape corresponding to the outer surface of the battery cell 100 and may at least partially surround the outer surface of the battery cell 100.

[0153] The second cell accommodating portion 412 may be provided behind the main plate 410 (-X-axis direction) along the longitudinal direction (Y-axis direction) of the main plate 410. Such a second cell accommodating portion 412 may accommodate a plurality of the battery cells 100 arranged in the longitudinal direction (Y-axis direction) of the battery pack 1. Therefore, a plurality of the second cell accommodating portions 412 may be provided behind the main plate 410 (-X-axis direction).

[0154] Each of the plurality of the second cell accommodating portions 412 is configured in a concave shape corresponding to the outer surface of the battery cell 100 and may at least partially surround the outer surface of the battery cell 100.

[0155] Such a plurality of the second cell accommodating portions 412 may be alternately arranged with the plurality of the first cell accommodating portions 411 in the front-rear direction (X-axis direction) of the main plate 410 so as to accommodate the battery cell 100, which is a cylindrical secondary battery, to the maximum extent.

[0156] A plurality of the inter-wings 413 may be provided and protrude along the width direction (X-axis direction) of the main plate 410 so as to partition between the plurality of first cell accommodation portions 411 and the plurality of second cell accommodation portions 412. Specifically, the plurality of the inter-wings 413 may be formed on both the front side (+X-axis direction) and the rear side (-X-axis direction) along the width direction (X-axis direction) of the main plate 410. More specifically, among the plurality of the inter-wings 413, the inter-wing 413 protruding forward (+X-axis direction) of the main plate 410 partitions the plurality of the first cell accommodation portions 411, and among the plurality of the inter-wings 413, the inter-wing 413 protruding rearward (-X-axis direction) of the main plate 410 may partition the plurality of the second cell accommodation portions 412.

[0157] The bottom rib 415 is provided at the bottom of the main plate 410 and can support the bottom of the battery cell 100 when the battery cell 100 is accommodated in the main plate 410.

[0158] Such a bottom rib 415 may be formed to protrude downward (-Z-axis direction) from the bottom of the battery cell 100 when the battery cell 100 is accommodated in the main plate 410.

[0159] The bus bar guide protrusion 416 is for fixing the connection bus bar unit 230 when assembling the bus bar assembly 200, is provided on the upper surface of the main plate 410, and at least one may be provided. Hereinafter, in this embodiment, the description will be limited to the case where a plurality of the bus bar guide protrusions 416 are provided.

[0160] When assembling the busbar assembly 200, the plurality of busbar guide protrusions 416 can be inserted into the guide holes 246 of the busbar cover 240 to guide the accurate placement of the connecting busbar unit 230. Since the connecting busbar unit 230 is inserted or coupled to the plurality of busbar guide protrusions 416 and fixed, welding processes for electrical connection of the busbar assembly 200 can be performed more stably, and the welding quality during the welding process can be further improved.

[0161] The cooling unit insertion groove 417 is for accommodating the end of the cooling unit 300 and can be provided at the longitudinal (Y-axis direction) end of the main plate 410. The end of the cooling unit 300 can be placed within the cooling unit insertion groove 417 when the main plate 410 is joined, enabling more stable fixation.

[0162] The guide steps 418 can project at a predetermined height from both upper ends on both sides in the longitudinal (Y-axis direction) of the main plate 410. When the assembly of the side structure unit 400 is completed through the connection between the main plate 410 and an end plate 450 described later, the guide steps 418 can form the periphery of the side structure unit 400 together with the end guide steps 458 of the end plate 450 described later.

[0163] The end plates 450 are provided in a pair and can be provided on both sides of the outermost periphery in the width direction (X-axis direction) of the side structure unit 400. Such a pair of end plates 450 can accommodate and support the battery cell 100 together with the opposing main plates 410.

[0164] The pair of end plates 450 can be provided with terminal holes 456 and end guide steps 458.

[0165] The terminal holes 456 are for accommodating the connector terminals 290 and can be provided at one end of the end plate 450.

[0166] The end guide step 458 is formed along the upper edge of the end plate 450 and can project at the same height as the guide step 418. Such an end guide step 458 can form the periphery of the side structure unit 400 together with the guide step 418 of the main plate 410 when the assembly of the side structure unit 400 is completed.

[0167] Hereinafter, the coupling structure between the battery cell 100 and the cooling unit 300 through such a side structure unit 400 will be described in more detail.

[0168] FIGS. 18 and 19 are diagrams for explaining the coupling structure between the battery cell and the cooling unit through the side structure unit of FIG. 16.

[0169] Referring to FIGS. 18 and 19, first, among the battery cells 100, the cooling tube 310 of the cooling unit 300 is sandwiched between the battery cells 100 arranged in two rows before and after along the width direction (X-axis direction) of the battery pack 1 (see FIG. 2). In the front-rear direction (X-axis direction) of the battery cells 100 with the cooling tube 310 sandwiched therebetween, the side structure unit 400 can accommodate the battery cells 100 facing each other.

[0170] Specifically, in the width direction (X-axis direction) of the battery pack 1 (see FIG. 2), the end plate 450, battery cell 100, cooling tube 310, battery cell 100, and main plate 410 arranged on the outermost periphery are arranged, and again, the battery cell 100, cooling tube 310, battery cell 100, and main plate 410 can be coupled while being arranged in this order. Then, in the width direction (X-axis direction) of the battery pack 1 (see FIG. 2), the end plate 450 arranged on the opposite outermost periphery is finally arranged and coupled, and the coupling of the side structure unit 400 is completed, so that the battery cell 100 and the cooling unit 300 can be accommodated in the side structure unit 400.

[0171] Here, both ends of the cooling unit 300 can be inserted into the cooling unit insertion groove 417 when the main plates 410 are coupled to each other and when the main plate 410 and the end plate 450 are coupled, so as to prevent interference with the cooling unit 300 and more stably fix the cooling unit 300.

[0172] On the other hand, the cooling fluid inlet / outlet part 370 provided at one end of the cooling unit 300 can be disposed to protrude outside the side surface structure unit 400 for connection with an external cooling line or the like.

[0173] The side surface structure unit 400 according to the present embodiment can form the side outer contour structure of the battery pack 1 (see FIG. 2) while accommodating the battery cell 100 and the cooling unit 300 through the connection between the main plate 410 and the end plate 450 like this. That is, the side surface structure unit 400 can function as a pack case forming the appearance of the battery pack 1.

[0174] Accordingly, the battery pack 1 (see FIG. 1) according to the present embodiment can omit a separate additional pack case or pack housing structure through the side surface structure unit 400, reduce the manufacturing cost, and at the same time, reduce the overall size of the battery pack 1 and further increase the energy density.

[0175] Referring further to FIG. 2, the filling member 500 can fill the space between the cooling unit 300 and the plurality of battery cells 100 in the height direction (Z-axis direction) of the battery pack 1. On the other hand, in FIG. 2, for convenience of understanding, the filling member 500 is shown by a rectangular dotted line, but the filling member 500 can fill the entire space between the cooling unit 300 and the plurality of battery cells 100.

[0176] Such a filling member 500 can form the pack case structure of the battery pack 1 together with the side structure unit 400 by covering the upper and lower sides of the battery pack 1 (see FIG. 2).

[0177] In addition, the filling member 500 can more stably fix the plurality of battery cells 100, and at the same time, enhance the heat dissipation efficiency of the plurality of battery cells 100 to further improve the cooling performance of the battery cells 100.

[0178] Furthermore, the filling member 500 can prevent moisture, foreign matter, etc. from penetrating to the side of the battery cell 100, prevent chain ignition when a thermal event occurs due to an abnormality of the battery cell 100, and enhance the structural rigidity of the battery pack 1.

[0179] The filling member 500 may include a potting resin. The potting resin can be formed by injecting a resin substance in a loose state to the side of the plurality of battery cells 100 and curing it. Here, the injection of the resin substance can be performed at a normal temperature of about 15°C to 25°C to prevent thermal damage to the plurality of battery cells 100.

[0180] Specifically, the filling member 500 may include a silicone resin. However, it is not limited thereto, and in addition to the silicone resin, the filling member 500 may include other resin substances capable of improving the fixing and heat dissipation efficiency of the battery cell 100.

[0181] The filling member 500 has a preset viscosity and may include at least two substances. Specifically, the filling member 500 may be a mixture of a predetermined resin and beads at a preset ratio. The filling member 500 can reduce the cost of the potting resin through the mixing of the beads, and can adjust physical properties such as the viscosity of the filling member 500 according to the mixing ratio.

[0182] The filling member 500 may include glass bubbles as beads. The glass bubbles can reduce the specific gravity of the filling member 500 and increase the energy density with respect to weight. On the other hand, the filling member 500 may have a viscosity of about 250 cP when the main agent and the curing agent are mixed, and may have a viscosity of about 1590 cP when the glass bubbles are mixed at a ratio of 100:60 (resin: glass bubbles). Details regarding the mixing of the filling member 500 with the glass bubbles will be described later.

[0183] By covering the portion of the battery cell 100 that is not in contact with the cooling tube 310, the filling member 500 can guide the thermal equilibrium of the battery cell 100, prevent variations in the cooling of the battery cell 100, and prevent local deterioration of the battery cell 100. Further, by preventing local deterioration of the battery cell 100, the safety of the battery cell 100 can also be significantly improved.

[0184] In addition, when damage or the like due to an abnormal situation occurs in at least one specific battery cell 100 among the plurality of battery cells 100, the filling member 500 can serve as an insulator to prevent energization to the adjacent battery cell 100 side.

[0185] In addition to the battery cell 100, the filling member 500 can also be filled in the bus bar assembly 200. Specifically, the filling member 500 can be filled in the bus bar assembly 200 so as to cover the upper side of the bus bar assembly 200.

[0186] Here, in the vertical direction (Z-axis direction) of the battery cell 100, the filling member 500 can be continuously filled between the bus bar assembly 200 and the battery cell 100 without an insulating space or a separation space therebetween.

[0187] Thus, since the filling member 500 according to this embodiment is continuously filled without interruption between the battery cell 100 and the bus bar assembly 200, uniform heat dissipation without variation in heat dissipation can be realized in the region between the battery cell 100 and the bus bar assembly 200, and the cooling performance of the battery pack 1 can be significantly enhanced.

[0188] Furthermore, the filling member 500 can also be filled in a portion excluding the outer surface of the side structure unit 400. Here, the filling member 500 can be continuously filled without interruption in the battery cell 100, the bus bar assembly 200, and the side structure unit 400. Thereby, the cooling performance of the battery pack 1 can be further improved.

[0189] Also, the filling member 500 can further include a material having a high specific heat performance. Thereby, the filling member 500 increases the thermal mass and delays the temperature rise of the battery cell 100 even in situations such as rapid charge and discharge of the battery cell 100, thereby preventing a rapid temperature rise of the battery cell 100.

[0190] Also, the filling member 500 can further include a material having a high heat resistance performance. Thereby, when a thermal event such as overheating occurs in at least one specific battery cell 100 among the plurality of battery cells 100, the filling member 500 can effectively prevent thermal runaway to the adjacent battery cell side.

[0191] Also, the filling member 500 can further include a material having a high flame retardant performance. Thereby, when a thermal event such as overheating occurs in at least one specific battery cell 100 among the plurality of battery cells 100, the filling member 500 can minimize the risk of fire occurrence.

[0192] Hereinafter, the formation of the pack case structure by injecting such a filling member 500 will be described in more detail.

[0193] FIGS. 20 to 22 are diagrams for explaining the formation of the pack case structure through the injection of the filling member into the battery pack shown in FIG. 2.

[0194] Referring to FIGS. 20 to 22, an operator or the like can form the pack case structures on the upper and lower sides of the battery pack 1 (see FIG. 2) through the filling member 500 containing the resin material by injecting and applying the filling member 500 in which the resin and the glass bubbles are mixed using the resin injection device I. Specifically, the filling member 500 can cover the upper side of the bus bar assembly 200 on the upper side (+Z-axis direction) of the battery pack 1 and fill up to the protruding height h4 of the bottom rib 415 while covering the bottom of the battery cell 100 on the lower side (-Z-axis direction) of the battery pack 1. Here, the protruding height h4 of the bottom rib 415 can be designed to be a predetermined height considering the injection amount of the filling member 500.

[0195] During the injection and application process of the filling member 500 using the resin injection device I, an injection guide S can be provided at the bottom of the side structure unit 400 so as to prevent the resin from flowing out downward (-Z-axis direction) during the injection of the filling member 500. The injection guide S can be composed of a Teflon (registered trademark) material or the like for easy detachment after the hardening of the filling member 500.

[0196] On the other hand, in the injection and application process of the filling member 500, it is important to reduce the manufacturing cost and manufacturing time so as to improve the manufacturing efficiency, and to further enhance the effect of the filling member 500 to be injected.

[0197] In order to reduce the manufacturing cost and manufacturing time, more rapid injection of the filling member 500 is required. The injection speed of the filling member 500 can be determined by, for example, the viscosity of the filling member 500, the structure of the side structure unit 400 that houses the battery cell 100, and the discharge flow rate of the resin injection device I.

[0198] Here, in relation to the viscosity of the filling member 500, a low-viscosity resin can be injected when injecting the filling member 500. Since the filling speed of the resin becomes slower as the viscosity increases, in order to improve manufacturing efficiency, a low-viscosity resin that can be filled at a specific speed or higher can be applied.

[0199] For example, if the filling amount of the filling member 500 is 600 ml and the target process time is 100 seconds, the filling member 500 must be filled under a flow rate condition of 6 ml / second. Considering this, injection of a low-viscosity resin is important when injecting the filling member 500, and according to the present embodiment, the filling member 500 can have a viscosity of 2000 cP or less.

[0200] Furthermore, as described above, glass bubbles can be mixed into the filling member 500 in order to reduce the cost of the potting resin and adjust physical properties such as the viscosity.

[0201] FIG. 23 is a graph showing test results for viscosity and manufacturing cost according to the mixing ratio of the filling member of the battery pack shown in FIG. 2.

[0202] Referring to FIG. 23, the filling member 500 can be mixed at a ratio considering both the optimal viscosity and manufacturing cost, etc. FIG. 23 schematically shows the results in Table 1 below.

[0203] In FIGS. 23 and Table 1, the test was performed with the ratio of the content of glass bubbles, that is, beads, as resin:beads = 100:X (%) and X in 10-unit increments from 0 to 80. In the test, the viscometer was of the LV type, set at spindle No. 63 and 12 RPM.

[0204] The test method is as follows: First, move a predetermined mass of Agent A and Agent B into containers respectively. Then, measure the mass of the beads for Agent A and Agent B and drop them into the respective containers for mixing. Next, after moving Agent A and Agent B into a 100 ml container, use a stirrer to mix them at 1000 RPM for 10 minutes, and measure the viscosity of the mixed resin with a viscometer.

[0205]

Table 1

[0206] As shown in the results of Figure 23 and Table 1, it can be seen from the test results that as the bead content increases, the viscosity increases and the cost is reduced. As described above, since the viscosity of the filling member 500 is preferably 2000 cP or less, in this embodiment, the mixing ratio of the resin and the beads (glass bubbles) can be 100:60 (resin: glass bubbles). According to this embodiment, the filling member 500 can have a viscosity of about 1590 cP by mixing the resin and the glass bubbles at a ratio of 100:60. As an example, in this embodiment, based on the 24S 4P standard, the required resin injection amount is 3.5 L, and the resin flow area between the battery cell 100, the cooling unit 300, and the side structure unit 400 is about 20,000 mm 2 When it is as described above, the total area of the opening spaces of the filling member injection holes 242 and 244 can be designed to be equal to or greater than the resin flow area. That is, the total area of the opening spaces of the filling member injection holes 242 and 244 can be formed to have an area larger than 20,000 mm 2

[0207] Under the above conditions, if the filling member 500 with a viscosity of 1590 cP and a mixing ratio of the resin and the glass bubbles of the filling member 500 of 100:60 is injected at a resin injection flow rate of 0.37 LPM, the filling member 500 can be injected up to 3.5 L, which is the required resin injection amount, by continuously injecting the filling member 500 for about 9 minutes and 30 seconds without a time delay during injection.

[0208] ​Thus, according to the present embodiment, by forming the total area of the opening spaces of the filling member injection holes 242 and 244 to be larger than the resin flow area and injecting the low-viscosity mixed filling member 500, no injection delay of the filling member 500 occurs during the injection of the filling member 500, and a desired amount of the filling member 500 can be effectively injected within the target process time.

[0209] On the other hand, during the injection and coating process of the filling member 500, the side structure unit 400 can, together with the injection guide S, serve as a mold for preventing the outflow of resin while supporting the battery cell 100 and the cooling unit 300.

[0210] Thereby, in the present embodiment, the side structure unit 400 can significantly improve the working efficiency while reducing the manufacturing cost without the need for an additional injection guide jig structure in the side direction during the injection and coating process of the filling member 500.

[0211] Furthermore, the side structure unit 400 guides the fixed-position arrangement of the connection busbar unit 230 through the busbar guide protrusion 416 inserted into the connection busbar unit 230, so that it can effectively prevent the twisting and displacement of the connection busbar unit 230 that may occur during the injection of the filling member 500.

[0212] Also, the guide step 418 and the end guide step 458 formed on the upper edge of the side structure unit 400 can enhance the injection accuracy of the filling member 500 during the injection of the filling member 500, making it easier to inject the filling member 500 to more reliably cover the busbar assembly 200, and can also effectively prevent the filling member 500 from overflowing.

[0213] Here, the side structure unit 400 exposes components such as those connected to external devices such as the interconnection board 260, the connector terminals 290, and the cooling fluid inlet / outlet 370 to the outside. Therefore, when injecting or applying the filling member 500, problems such as interference with these components do not occur.

[0214] Accordingly, in the present embodiment, since the pack case structure of the battery pack 1 (see FIG. 1) is formed through the side structure unit 400 and the filling member 500, compared to the case of forming the pack case structure as a complex assembly of a plurality of plates as in the prior art, the assembly process of the battery pack 1 can be simplified, the manufacturing cost can be significantly reduced, and price competitiveness can also be ensured.

[0215] Furthermore, according to the present embodiment, compared to the conventional pack case structure provided as a cell frame structure including an assembly of a plurality of plates, through the pack case structure formed by the side structure unit 400 and the filling member 500, the size of the entire battery pack 1 can be reduced and the energy density can also be significantly increased.

[0216] Hereinafter, a manufacturing method of the battery pack 1 having the pack case structure formed by the side structure unit 400 and the filling member 500 according to an embodiment of the present invention will be schematically described.

[0217] When manufacturing the battery pack 1, an operator or the like can arrange the cooling unit 300 between a plurality of the battery cells 100 and align the battery cells 100 and the cooling unit 300 so that they can be accommodated using the side structure unit 400. Also, an operator or the like can electrically connect the battery cells 100 within the opening spaces of the filling member injection holes 242 and 244 of the bus bar assembly 200 in which the filling member injection holes 242 and 244 are formed above the plurality of the battery cells 100. Next, an operator or the like can inject and apply the filling member 500 from the upper side (+Z-axis direction) to the lower side (-Z-axis direction) of the battery cells 100 along the vertical direction (Z-axis direction) of the battery cells 100 through the opening spaces of the filling member injection holes 242 and 244.

[0218] FIG. 24 is a diagram for explaining an automobile according to another embodiment of the present invention.

[0219] Referring to FIG. 24, the automobile V can be an electric vehicle or a hybrid vehicle and can include at least one battery pack 1 of the above-described embodiments as an energy source.

[0220] In the case of the present embodiment, since the above-described battery pack 1 is provided with a compact structure having a high energy density, when mounted on the automobile V, it is easy to realize a modular structure of a plurality of battery packs 1, and a relatively high degree of mounting freedom can be ensured even in the internal spaces of various shapes of the automobile V. That is, in the present embodiment, at least one battery pack 1 can be provided as a battery pack case structure that is easy to realize a modular structure and has a high degree of mounting freedom.

[0221] Also, so that the side structure unit 400 can protect a plurality of the battery cells 100 during a collision in the front and rear of the automobile V, the longitudinal direction of at least one battery pack 1 can be arranged perpendicular to the longitudinal direction of the automobile V.

[0222] With the various embodiments as described above, it is possible to provide a battery pack 1 capable of improving the energy density with a simpler structure, and an automobile V including the battery pack 1.

[0223] Also, with the various embodiments as described above, it is possible to provide a battery pack 1 capable of improving the manufacturing efficiency by reducing the manufacturing cost and manufacturing time, and an automobile V including the battery pack 1.

[0224] As described above, the preferred embodiments of the present invention have been illustrated and described. However, the present invention is not limited to the specific embodiments described above, and various modifications can be made by those having ordinary knowledge in the technical field to which the present invention belongs without departing from the gist of the present invention described in the claims. Such modifications should not be individually understood from the technical idea and prospect of the present invention.

Explanation of Reference Numerals

[0225] 1 Battery pack 100 Battery cell 200 Bus bar assembly 242, 244 Filling member injection hole 500 Filling member

Claims

1. A battery pack, comprising: a plurality of battery cells; a filling member filled in the space between the plurality of battery cells; a bus bar assembly electrically connected to the plurality of battery cells and having a filling member injection hole formed therein for injecting the filling member; The battery pack including the above components.

2. The battery pack according to claim 1, wherein the bus bar assembly is electrically connected to the positive and negative electrodes of the battery cell within the opening space of the filling member injection hole.

3. The battery pack according to claim 2, wherein the opening space of the filling member injection hole exposes both the positive and negative electrodes of the battery cell.

4. The battery pack according to claim 2, wherein the total area of the opening space is larger than the flow area of the filling member flowing between the battery cells during injection of the filling member.

5. The battery pack according to claim 1, wherein the filling member has a preset viscosity and contains at least two substances.

6. The battery pack according to claim 5, wherein the filling member is a mixture of a preset resin and beads in a preset ratio.

7. The battery pack according to claim 5, wherein the preset resin includes a silicone resin.

8. The battery pack according to claim 5, wherein the preset beads include glass bubbles.

9. The bus bar assembly includes: a pair of bus bar covers disposed on one side of the plurality of battery cells and having the filling member injection hole formed therein; a sub-bus bar provided between the pair of bus bar covers and connected to the positive and negative electrodes of the battery cell; The battery pack according to claim 2 including the above components.

10. The battery pack according to claim 9, wherein the pair of bus bar covers includes a polyimide film.

11. The battery pack according to claim 9, wherein the sub-bus bar is provided in a single layer and inserted between the pair of bus bar covers.

12. The sub-bus bar includes: a bus bar bridge inserted between the pair of bus bar covers; a positive electrode connection portion extending from the bus bar bridge, exposed within the opening space of the filling member injection hole, and connected to the positive electrode of the battery cell; a negative electrode connection portion extending from the bus bar bridge, exposed within the opening space of the filling member injection hole, and connected to the negative electrode of the battery cell. The battery pack according to claim 11, comprising

13. A plurality of the filling member injection holes are provided, The plurality of the filling member injection holes include a positive electrode bus bar hole that exposes the positive electrode connection portion and has an opening space larger than the size of the positive electrode connection portion, and a negative electrode bus bar hole that exposes the negative electrode connection portion and has an opening space larger than the size of the negative electrode connection portion, The battery pack according to claim 12, comprising

14. A plurality of the filling member injection holes are provided, The battery pack according to claim 12, wherein each of the plurality of the filling member injection holes exposes both the positive electrode connection portion and the negative electrode connection portion within one opening space.

15. The battery pack according to claim 14, wherein each of the plurality of the filling member injection holes has an opening space larger than the combined size of the positive electrode connection portion and the negative electrode connection portion.

16. The battery pack according to claim 13, wherein the positive electrode bus bar hole and the negative electrode bus bar hole are arranged to face each other with the bus bar bridge interposed therebetween.

17. A method for manufacturing a battery pack, comprising a step of disposing a cooling unit between a plurality of battery cells and aligning the battery cells and the cooling unit using a side structure unit so as to be accommodatable, a step of electrically connecting the battery cells within an opening space of a filling member injection hole of a bus bar assembly having the filling member injection hole from above the plurality of battery cells, a step of injecting and applying a filling member from above the battery cells along the vertical direction of the battery cells through the opening space of the filling member injection hole, A method for manufacturing a battery pack, comprising

18. The method for manufacturing a battery pack according to claim 17, wherein the filling member is a mixture of a predetermined resin and beads mixed at a preset ratio.

19. The method for manufacturing a battery pack according to claim 18, wherein the mixing ratio of the predetermined resin and beads is 100:60 (resin: glass bubbles).

20. An automobile comprising at least one battery pack according to any one of claims 1 to 16.

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