Improved cell lead connection structure and battery module employing the same, battery pack and transportation means including the battery module

Abstract

The present invention provides an improved cell lead connection structure characterized by comprising: a fastening frame having a plurality of first lead slits formed therein through which cell leads of a plurality of battery cells are each drawn out; and a rotating structure rotatably coupled to the fastening frame, wherein a second lead slit is formed to allow a plurality of cell leads drawn out through the first lead slits to be inserted therein, and the plurality of cell leads inserted into the second lead slits can be wound while in contact with each other.

Description

Technology Field

[0001] The present invention relates to an improved cell lead connection structure and a battery module employing the same, a battery pack including the battery module, and a means of transport. Specifically, it relates to an improved cell lead connection structure capable of reducing the time required for an assembly process and mitigating the tensile force applied to the cell tab and cell lead when swelling occurs, a battery module employing the same, a battery pack including the battery module, and a means of transport. Background Technology

[0003] Currently commercialized rechargeable batteries include nickel-cadmium, nickel-hydrogen, nickel-zinc, and lithium-ion batteries. Among these, lithium-ion batteries are gaining attention for their advantages, such as the ability to freely charge and discharge with almost no memory effect compared to nickel-based batteries, a very low self-discharge rate, and high energy density.

[0004] These lithium secondary batteries primarily use lithium-based oxides and carbon materials as the positive and negative active materials, respectively.

[0005] A lithium secondary battery comprises an electrode assembly in which a positive plate and a negative plate, each coated with a positive active material and a negative active material respectively, are arranged with a separator in between, and an outer casing that seals and stores the electrode assembly together with an electrolyte, namely a battery pouch outer casing.

[0006] Generally, lithium secondary batteries can be classified according to the shape of the casing into can-type secondary batteries, in which the electrode assembly is embedded in a metal can, and pouch-type secondary batteries, in which the electrode assembly is embedded in a pouch of aluminum laminate sheet.

[0007] Recently, secondary batteries are being widely used not only in small devices such as portable electronic devices, but also in medium to large devices such as automobiles and power storage devices.

[0008] When using secondary batteries in such medium-to-large devices, a large number of secondary batteries are electrically connected to increase capacity and output.

[0009] In particular, pouch-type secondary batteries are widely used in these medium-to-large devices due to the advantage of easy stacking.

[0010] In order for secondary batteries to be electrically connected inside a battery module, cell leads are interconnected, and the connection parts can be welded to maintain such a connection state.

[0011] Furthermore, the battery module may have parallel and / or series electrical connections between secondary batteries, for which one end of the cell lead may be fixed in contact with a busbar for electrical connection between each secondary battery by means such as welding.

[0013] FIG. 1 is a drawing showing a state in which a busbar is coupled to a busbar frame in a battery module according to the prior art, and FIG. 2 is a drawing showing a state in which a cell lead passing through a lead slit formed in the busbar frame of FIG. 1 is welded to the busbar.

[0014] A busbar frame (2) typically equipped with a busbar (3) is used for electrical connection between multiple pouch-type battery cells forming a cell stack.

[0015] In this case, each cell lead (1) of adjacent pouch-type battery cells passes through a lead slit (2a) formed in the busbar frame (2), and a pair of cell leads (1) that pass through the lead slit (2a) are each joined by welding to a busbar (3) made of a conductive material fixed on the busbar frame (2).

[0016] Thus, adjacent battery cells are electrically connected to each other.

[0017] A plurality of busbars (3) may be provided on the busbar frame (2), and a pair of cell leads (1) may be connected to each busbar (3).

[0018] Of course, depending on the electrical connection type, three or more cell leads (1) may be combined to a single busbar (3).

[0019] In this way, according to a conventional battery module structure that electrically connects battery cells using a bus bar (3) made of a conductive material, a structure capable of fixing the bus bar (3) must be formed in the bus bar frame (2).

[0020] In addition, according to this conventional battery module structure, an additional process of welding the cell lead (1) to the bus bar (3) is required.

[0021] In Fig. 2, reference numeral 4 is a welded part.

[0022] As mentioned above, conventional battery modules have a problem in that the time and cost for welding the cell leads increase because the cell leads passing through the lead slits formed in the busbar frame are welded to the busbar.

[0023] In addition, as the cell leads are welded to the busbar in this manner, there was a problem in that if an issue occurred in any one battery cell, the individual battery cell could not be replaced, and the entire cell stack had to be replaced, which increased the associated costs.

[0024] In addition, conventional battery modules have a problem in which battery module performance deteriorates, such as cell tab disconnection, because welding is performed between the cell lead and the busbar; when swelling occurs in the battery cell, tensile force is applied to the cell lead. Prior art literature

[0026] (Patent Document 0001) KR 10-2022-0011529 A (Published Jan. 28, 2022) The problem to be solved

[0027] The present invention is designed to solve the various problems of the prior art as described above, and aims to provide an improved cell lead connection structure that can reduce the time and cost required for the assembly process by eliminating the need for welding between the cell lead and the busbar, a battery module employing the same, a battery pack including the battery module, and a means of transport.

[0028] Another objective of the present invention is to provide an improved cell lead connection structure that allows individual battery cells to be replaced when an issue occurs in any one battery cell, thereby eliminating the need to replace the entire cell stack, a battery module employing the same, a battery pack including the battery module, and a means of transport.

[0029] Another objective of the present invention is to provide an improved cell lead connection structure capable of preventing damage to the battery cell, such as cell tab disconnection, by alleviating the tensile force applied to the cell lead when swelling occurs in the battery cell, a battery module employing the same, a battery pack including the battery module, and a means of transport. means of solving the problem

[0031] To achieve the above objectives, an embodiment of an improved cell lead connection structure according to the first aspect of the present invention comprises: a fastening frame having a plurality of first lead slits formed therein through which the cell leads of a plurality of battery cells are each drawn out; and a rotating structure rotatably coupled to the fastening frame, wherein a second lead slit is formed to allow the plurality of cell leads drawn out through the first lead slits to be inserted therein, and the plurality of cell leads inserted into the second lead slits can be wound while in contact with each other.

[0032] The above-mentioned rotating structure is formed in the shape of a cylinder having a predetermined length, and a second lead slit may be formed along the length direction.

[0033] The second lead slit above may have a shape in which the top is closed and the bottom is open.

[0034] A pair of cell leads inserted into the second lead slit above may have the same polarity.

[0035] A pair of cell leads inserted into the second lead slit above may have different polarities.

[0036] A connecting portion may be formed on the lower side of the above-mentioned connecting frame, to which the lower end of the above-mentioned rotating structure is rotatably connected.

[0037] The above-mentioned connecting portion is formed in a groove shape so as to be connected to the lower end of the rotating structure, and may have an inner surface with a circular radial cross-section of the groove corresponding to the outer surface of the lower end of the rotating structure.

[0038] A first screw thread may be formed on the inner surface of the above-mentioned coupling part, and a second screw thread corresponding to the first screw thread may be formed on the lower outer surface of the above-mentioned rotating structure.

[0039] On the bottom surface of the above-mentioned coupling part, a fitting projection may be formed protruding upward along the longitudinal direction of the second lead slit so as to be fitted into the second lead slit.

[0040] The above-mentioned fitting projection is formed in the shape of a cylinder, and the inner circumference of the second lead slit can be formed to correspond to the outer circumference of the fitting projection.

[0041] The outer diameter of the above-mentioned fitting projection may be formed to be equal to or smaller than the inner diameter of the above-mentioned second lead slit.

[0042] The above-mentioned rotating structure may be formed in a hollow or solid form.

[0043] A plurality of cell leads, which are inserted into the second lead slit and wound around the rotating structure in a mutually contacting state, can maintain the state of being wound around the rotating structure by the frictional force between the rotating structure and the cell leads and the frictional force between the plurality of cell leads.

[0044] The above-mentioned rotating structure can be formed from a non-conductive material.

[0045] A battery module according to the second aspect of the present invention may employ the aforementioned improved cell lead connection structure.

[0046] A battery pack according to a third aspect of the present invention may include the aforementioned battery module and a pack case in which a plurality of the battery modules are provided and stored.

[0047] A means of transport according to the fourth aspect of the present invention may include the aforementioned battery module, include the aforementioned battery pack, or be configured by combining the aforementioned battery module and the aforementioned battery pack. Effects of the invention

[0049] According to the means for solving the aforementioned problem, the present invention has the following effects.

[0050] The present invention has the effect of reducing the time and cost required for the assembly process by replacing the existing busbar with a plurality of cell leads inserted into a second lead slit of a rotating structure made of a non-conductive material, and then rotating the rotating structure so that the plurality of cell leads are electrically connected while being wound in contact with each other, thereby eliminating the need for welding between the cell leads and the busbar as in the conventional method.

[0051] In addition, the present invention allows individual battery cells to be replaced by separating the cell lead of a battery cell from a rotating structure when an issue occurs in any one battery cell, thereby eliminating the need to replace the entire cell stack.

[0052] In addition, the present invention is configured so that when swelling occurs in the battery cell, the rotating structure rotates, thereby relieving the tensile force applied to the cell lead and preventing damage to the battery cell, such as cell tab disconnection.

[0053] In addition, the present invention is implemented in a manner where the cell lead is wound around a rotating structure, thereby reducing the exposed area of ​​the cell lead compared to conventional busbars, which has the effect of reducing the risk of short circuits caused by leakage of cell electrolyte or ingress of foreign matter. Brief explanation of the drawing

[0055] FIG. 1 is a drawing showing a state in which a busbar is coupled to a busbar frame in a battery module according to an embodiment of the prior art. Figure 2 is a drawing showing the state in which a cell lead that has passed through a lead slit formed in the busbar frame of Figure 1 is welded to the busbar. FIG. 3 is a drawing showing the state in which a rotating structure is coupled to a fastening frame in a battery module according to one embodiment of the present invention. FIGS. 4 to 7 are drawings illustrating, in sequence, the process of a cell lead passing through a first lead slit formed in a fastening frame in the battery module of FIG. 3 and being inserted into a second lead slit of a rotating structure. FIG. 4 shows the state in which the cell lead has passed through the first lead slit. FIG. 5 shows the state in which the rotating structure is moved from the upper side to the lower side of the cell lead to insert the cell lead into the second lead slit. FIG. 6 shows the rotating structure being rotated while the cell lead is inserted into the second lead slit. FIG. 7 shows the rotating structure being moved downward to be connected to a coupling part formed in the fastening frame. FIG. 8 is a schematic diagram showing the state in which a rotating structure is separated from a coupling portion formed on a fastening frame in a battery module according to one embodiment of the present invention. Figure 9 is a schematic diagram showing the state in which a rotating structure is coupled to the joint of Figure 8. FIG. 10 is a schematic diagram showing the configuration of a battery pack according to the present invention. FIG. 11 is a schematic diagram showing a car including the battery pack of FIG. 10. Specific details for implementing the invention

[0056] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Accordingly, in some embodiments, well-known process steps, well-known device structures, and well-known techniques are not specifically described to avoid the present invention being interpreted ambiguously. Throughout the specification, like reference numerals refer to like components.

[0057] In drawings, thicknesses may be enlarged to clearly represent multiple layers and regions. Throughout the specification, the same reference numerals are used for similar parts. When a part such as a layer, film, region, or plate is described as being "above" another part, this includes not only cases where it is "immediately above" another part, but also cases where there is another part in between. Conversely, when a part is described as being "immediately above" another part, it means that there is no other part in between. Furthermore, when a part such as a layer, film, region, or plate is described as being "below" another part, this includes not only cases where it is "immediately below" another part, but also cases where there is another part in between. Conversely, when a part is described as being "immediately below" another part, it means that there is no other part in between.

[0058] Typically, a busbar frame equipped with busbars is used for electrical connection between multiple pouch-type battery cells that form a cell stack.

[0059] In this case, the cell leads (or electrode leads) of each adjacent pouch-type battery cell pass through a lead slit formed in the busbar frame, and the pair of cell leads passing through the lead slit are each joined by welding to a busbar made of conductive material fixed on the busbar frame.

[0060] Thus, adjacent battery cells are electrically connected to each other.

[0061] The present invention discloses an improved cell lead connection structure that can reduce the time and cost required for the assembly process by replacing the existing busbar with a rotating structure made of a non-conductive material to electrically connect a plurality of cell leads, thereby eliminating the need for welding between the cell leads and the busbar as in the conventional method.

[0062] FIG. 3 is a drawing showing the state in which a rotating structure is coupled to a fastening frame in a battery module according to one embodiment of the present invention.

[0063] An improved cell lead connection structure according to one embodiment of the present invention comprises a fastening frame (10) having a plurality of first lead slits (12) formed therein through which cell leads (20) of a plurality of battery cells are each drawn out, and a rotating structure (30) rotatably coupled to the fastening frame (10) so as to allow a plurality of cell leads (20) drawn out through the first lead slits (12) to be inserted therein and so as to allow a plurality of cell leads (20) inserted into the second lead slits (32) to be wound while in contact with each other.

[0064] The battery module (M) according to the present invention adopts such an improved cell lead connection structure and comprises a cell stack (not shown), a fastening frame (10), and a rotating structure (30).

[0065] The cell stack comprises a plurality of battery cells each having a pair of cell leads (20) (electrode leads).

[0066] The battery cell may be, for example, a pouch-type battery cell, in which case a pair of cell leads (20) having different polarities may be drawn out in opposite directions or in the same direction.

[0067] Accordingly, multiple battery cells can be connected in series or in parallel.

[0068] The cell lead (20) is divided into a positive lead connected to the positive tab and a negative lead connected to the negative tab, and each of the positive lead and the negative lead is drawn out to the outside of the battery cell case.

[0069] The fastening frame (10) is formed in the shape of a roughly rectangular plate and is placed on each side in the longitudinal direction of the cell stack.

[0070] It is preferable that such a fastening frame (10) be formed of a non-conductive material.

[0071] In the fastening frame (10), a plurality of first lead slits (12) are formed at predetermined intervals so that the cell leads (20) of the battery cell can pass through.

[0072] The rotating structure (30) is made of a non-conductive material and is intended to electrically connect the cell leads (20) of different battery cells.

[0073] This rotating structure (30) is formed in the shape of a cylinder having a predetermined length, and a second lead slit (32) may be formed along the length direction.

[0074] The width of the second lead slit (32) is sufficient if it allows a plurality of cell leads (20) of any thickness to be fitted.

[0075] The second lead slit (32) may have a shape in which the top is closed and the bottom is open.

[0076] A pair of cell leads (20) inserted into the second lead slit (32) may have the same polarity.

[0077] Additionally, a pair of cell leads (20) fitted into the second lead slit (32) may have different polarities.

[0078] The rotating structure (30) can be formed in a hollow or solid form.

[0079] In this way, a plurality of cell leads (20) that are inserted into the second lead slit (32) and wound around a rotating structure (30) in a mutually contacted state can maintain the state of being wound around the rotating structure (30) by the frictional force between the rotating structure (30) and the cell leads (20) and the frictional force between the plurality of cell leads (20).

[0081] FIGS. 4 to 7 are drawings illustrating, in sequence, the process of a cell lead passing through a first lead slit formed in a fastening frame in the battery module of FIG. 3 and being inserted into a second lead slit of a rotating structure. FIG. 4 shows the state in which the cell lead has passed through the first lead slit. FIG. 5 shows the state in which the rotating structure is moved from the upper side to the lower side of the cell lead to insert the cell lead into the second lead slit. FIG. 6 shows the rotating structure being rotated while the cell lead is inserted into the second lead slit. FIG. 7 shows the rotating structure being moved downward to be connected to a coupling part formed in the fastening frame.

[0082] First, with a plurality of cell leads (20) that have passed through the first lead slit (12) formed in the fastening frame (10) overlapping each other (see FIG. 4), the rotating structure (30) is moved from the upper side to the lower side of the cell leads (20) so that the plurality of cell leads (20) are inserted into the second lead slit (32) through the lower end opened in the second lead slit (32) of the rotating structure (30) (see FIG. 5).

[0083] A plurality of cell leads (20) inserted into the second lead slit (32) of the rotating structure (30) are wound around the outer surface of the rotating structure (30) by rotating the rotating structure (30) in one direction (see FIG. 6), and the rotating structure (30) is moved downward so that the rotating structure (30), with the plurality of cell leads (20) wound overlapping, is joined to a joining part (14) formed on the fastening frame (10) (see FIG. 7).

[0084] A plurality of cell leads (20) that are inserted into the second lead slit (32) and wound around a rotating structure (30) in a mutually contacted state can maintain the state of being wound around the rotating structure (30) by the frictional force between the rotating structure (30) and the cell leads (20) and the frictional force between the plurality of cell leads (20).

[0085] As such, the present invention has the advantage of reducing the time and cost required for the assembly process by replacing the existing busbar with a plurality of cell leads (20) inserted into the second lead slit (32) of a rotating structure (30) made of a non-conductive material, and then rotating the rotating structure (30) so that the plurality of cell leads (20) are electrically connected while in contact with each other, thereby eliminating the need for welding between the cell leads and the busbar as in the conventional method.

[0086] Meanwhile, as described above, when swelling occurs in a battery cell while a plurality of cell leads (20) are wound around a rotating structure (30), the rotating structure (30) is configured to rotate in the direction of tensile force application, thereby relieving the tensile force applied to the cell leads (20) and preventing damage to the battery cell, such as cell tab disconnection.

[0088] FIG. 8 is a schematic diagram showing a state in which a rotating structure is separated from a coupling portion formed on a fastening frame in a battery module according to one embodiment of the present invention, and FIG. 9 is a schematic diagram showing a state in which a rotating structure is coupled to the coupling portion of FIG. 8.

[0089] On the lower side of the fastening frame (10), a connecting part (14) may be formed to which the lower end of the rotating structure (30) is rotatably connected.

[0090] Such a connecting part (14) is formed in a groove shape so as to be connected to the lower end of the rotating structure (30), and may have an inner surface with a circular radial cross-section of the groove corresponding to the lower outer surface of the rotating structure (30).

[0091] A first screw thread (14a) may be formed on the inner surface of the connecting part (14), and a second screw thread (34) corresponding to the first screw thread (14a) may be formed on the lower outer surface of the rotating structure (30).

[0092] As such, the connection method between the rotating structure (30) and the connecting part (14) can be implemented using a screw connection method, and any other configuration that enables the rotation of the rotating structure (30) can be substituted.

[0093] In addition, the rotation of the rotating structure (30) can be implemented in a rotation method that allows it to rotate freely without angle restrictions, or in a limited rotation method that allows it to rotate only by a certain angle.

[0094] On the bottom surface of the connecting part (14), a fitting projection (14b) may be formed protruding upward along the length direction of the second lead slit (32) so as to be fitted into the open bottom of the second lead slit (32).

[0095] The insertion projection (14b) is formed in the shape of a cylinder, and the inner circumference of the second lead slit (32) can be formed to correspond to the outer circumference of the insertion projection (14b).

[0096] The outer diameter of the insertion projection (14b) can be formed to be the same as or smaller than the inner diameter of the second lead slit (32).

[0097] These fitting protrusions (14b) are intended to prevent the width of the second lead slit (32) from narrowing over time.

[0099] FIG. 10 is a schematic diagram showing the configuration of a battery pack according to the present invention, and FIG. 11 is a schematic diagram showing a vehicle including the battery pack of FIG. 10.

[0100] The battery pack (P) includes the aforementioned battery module (M) and a pack case (C) in which a plurality of battery modules (M) are provided and stored.

[0101] This battery pack (P) can be provided in the vehicle (V) as a fuel source for the vehicle.

[0102] For example, the battery pack (P) can be provided in the vehicle (V) in an electric vehicle, a hybrid vehicle, and other ways in which the secondary battery pack (P) can be used as a fuel source.

[0103] As another example, a means of transport including a vehicle (V) may be provided with a configuration in which the aforementioned battery module (M) and the aforementioned battery pack (P) are combined.

[0104] In addition, it goes without saying that the battery pack (P) can be equipped in other devices, equipment, and facilities, such as an energy storage system that utilizes the battery, in addition to the vehicle (V).

[0105] Thus, since the device, mechanism, and facility equipped with the battery pack (P), such as the battery pack (P) and the automobile (V) according to the present invention, includes the aforementioned battery module (M), it is possible to realize a battery pack (P) having all the advantages of the aforementioned battery module (M) and a device, mechanism, and facility such as an automobile equipped with such a battery pack (P). Explanation of the symbols

[0107] 10: Fastening frame 12: 1st lead slit 14 : Joint 14a: First thread 14b : Insertion projection 20 : Cell Lead 30: Rotating structure 32: Second lead slit 34: Second thread M: Battery Module P: Battery pack C: Pack case V : Car

Claims

Claim 1 An improved cell lead connection structure characterized by comprising: a fastening frame having a plurality of first lead slits formed therein through which cell leads of a plurality of battery cells are each drawn out; and a rotating structure rotatably coupled to the fastening frame so as to allow a plurality of cell leads drawn out through the first lead slits to be inserted therein, and so as to allow a plurality of cell leads inserted into the second lead slits to be wound while in contact with each other. Claim 2 An improved cell lead connection structure according to claim 1, wherein the rotating structure is formed in a cylindrical shape having a predetermined length and a second lead slit is formed along the longitudinal direction. Claim 3 In claim 2, the second lead slit has an improved cell lead connection structure having a shape in which the top is closed and the bottom is open. Claim 4 An improved cell lead connection structure according to claim 1, wherein a pair of cell leads fitted into the second lead slit have the same polarity. Claim 5 An improved cell lead connection structure according to claim 1, wherein a pair of cell leads fitted into the second lead slit have different polarities. Claim 6 An improved cell lead connection structure according to claim 3, wherein a coupling portion is formed on the lower side of the fastening frame to which the lower end of the rotating structure is rotatably coupled. Claim 7 An improved cell lead connection structure according to claim 6, wherein the coupling portion is formed in a groove shape so as to be coupled to the lower end of the rotating structure, and has an inner surface having a circular radial cross-section of the groove corresponding to the outer surface of the lower end of the rotating structure. Claim 8 An improved cell lead connection structure according to claim 7, wherein a first screw thread is formed on the inner surface of the coupling portion and a second screw thread corresponding to the first screw thread is formed on the lower outer surface of the rotating structure. Claim 9 An improved cell lead connection structure according to claim 7, wherein a fitting projection is formed protruding upwardly on the bottom surface of the coupling portion to be fitted into the second lead slit along the longitudinal direction of the second lead slit. Claim 10 An improved cell lead connection structure according to claim 9, wherein the fitting projection is formed in a cylindrical shape, and the inner circumference of the second lead slit is formed to correspond to the outer circumference of the fitting projection. Claim 11 An improved cell lead connection structure according to claim 10, wherein the outer diameter of the fitting projection is formed to be equal to or smaller than the inner diameter of the second lead slit. Claim 12 An improved cell lead connection structure according to claim 1, wherein the rotating structure is formed in a hollow or solid form. Claim 13 An improved cell lead connection structure according to claim 1, wherein a plurality of cell leads, which are inserted into the second lead slit and wound around the rotating structure in a mutually contacting state, maintain the state of being wound around the rotating structure by the frictional force between the rotating structure and the cell leads and the frictional force between the plurality of cell leads. Claim 14 The improved cell lead connection structure of claim 1, wherein the rotating structure is formed of a non-conductive material. Claim 15 A battery module employing an improved cell lead connection structure according to any one of claims 1 to 14. Claim 16 A battery pack comprising a battery module according to claim 15 and a pack case in which a plurality of battery modules are provided and stored. Claim 17 A means of transport comprising a battery module according to claim 15. Claim 18 A means of transport comprising a battery pack according to claim 16.

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