阅读说明：本技术 电池模块、制造电池模块的方法及包括电池模块的电池组 (Battery module, method of manufacturing the same, and battery pack including the same ) 是由 李暎浩 金成大 金修烈 朴秀彬 于 2020-07-10 设计创作，主要内容包括：根据本公开内容实施方式的电池模块包括：其中堆叠有多个电池单元的电池单元堆叠体、连接至电池单元堆叠体的汇流条框架、各自从电池单元堆叠体中包括的电池单元之中的彼此相邻的电池单元伸出的电池单元平台部、和各自从电池单元平台部伸出并且具有相同极性的电极引线,其中电极引线与同一汇流条重叠,并且在汇流条和电极引线的重叠部分处可具有至少两个焊接部。(The battery module according to an embodiment of the present disclosure includes: a battery cell stack in which a plurality of battery cells are stacked, a bus bar frame connected to the battery cell stack, battery cell lands each protruding from battery cells adjacent to each other among the battery cells included in the battery cell stack, and electrode leads each protruding from the battery cell lands and having the same polarity, wherein the electrode leads overlap the same bus bar, and may have at least two welding parts at overlapping portions of the bus bar and the electrode leads.)

1. A battery module, comprising:

a battery cell stack in which a plurality of battery cells are stacked,

a bus bar frame connected to the battery cell stack,

a cell platform portion each protruding from a cell adjacent to each other among the cells included in the cell stack, and

electrode leads each protruding from the battery cell platform and having the same polarity,

wherein the electrode lead overlaps the same bus bar and has at least two welding parts at an overlapping portion of the bus bar and the electrode lead.

2. The battery module as set forth in claim 1,

wherein the electrode leads are formed of N electrode leads, and the N electrode leads overlap the same bus bar,

wherein a first welding part where welding is performed between the N electrode leads, and a second welding part where welding is performed between N-1 electrode leads among the N electrode leads and an electrode lead closest to the bus bar is welded to the bus bar are formed.

3. The battery module of claim 2, wherein

The N electrode leads include a first electrode lead, a second electrode lead and a third electrode lead, and

the first electrode lead, the second electrode lead, and the third electrode lead are bent toward the same bus bar, and bending angles increase in the order of the first electrode lead, the second electrode lead, and the third electrode lead.

4. The battery module as set forth in claim 3,

wherein a length of the third electrode lead overlapping the bus bar is shorter than a length of the first electrode lead overlapping the bus bar.

5. The battery module as set forth in claim 1,

wherein the battery cell lands from which the electrode leads having the same polarity protrude have a spacing that narrows in a direction in which the electrode leads protrude.

6. A method of manufacturing a battery module, comprising the steps of:

a battery cell stack is formed by stacking a plurality of battery cells,

overlapping electrode leads, each of which protrudes from battery cells adjacent to each other among the battery cells, on the same bus bar, and

welding the electrode lead and the bus bar at least two different positions among the overlapping portions of the electrode lead and the bus bar.

7. The method of claim 6, wherein,

the welding of the electrode lead and the bus bar includes: a first welding part for welding the electrode leads adjacent to each other and a second welding part for welding the electrode leads adjacent to each other and the bus bar are formed.

8. The method of claim 7, further comprising:

fixing the electrode lead by pressing the electrode lead with a fixing jig before forming the first and second soldering parts.

9. The method of claim 8, wherein the first and second light sources are selected from the group consisting of,

wherein the fixing jig has a first opening corresponding to the first welding part and a second opening corresponding to the second welding part.

10. A battery pack comprising the battery module according to claim 1.

Technical Field

Cross Reference to Related Applications

This application claims the benefit of korean patent application No. 10-2019-0145974, filed by the korean intellectual property office at 11/14/2019, the entire disclosure of which is incorporated herein by reference.

The present disclosure relates to a battery module, a method of manufacturing the battery module, and a battery pack including the battery module, and more particularly, to a battery module having an improved welding structure, a method of manufacturing the battery module, and a battery pack including the battery module.

Background

The secondary battery is easily applied to various product groups and has electrical characteristics such as high energy density, which is commonly applied not only to portable devices but also to electric vehicles or hybrid vehicles driven by an electric drive source, energy storage systems, and the like. Such secondary batteries are receiving attention as a new environmentally friendly energy source for improving energy efficiency because they provide a major advantage of significantly reducing the use of fossil fuels, and also generate no by-products at all from the use of energy.

Small-sized mobile devices use one or more battery cells for each device, and medium-or large-sized devices such as vehicles require high power and large capacity. Therefore, a middle-or large-sized battery module having a plurality of battery cells electrically connected to each other is used.

In addition, as the demand for large-capacity structures used as energy storage sources continues to increase in recent years, there is an increasing demand for battery packs having a multi-module structure in which a plurality of battery modules each including a plurality of secondary batteries connected in series and/or parallel are integrated.

In addition, when a plurality of battery cells are connected in series or in parallel to constitute a battery pack, it is general to first constitute a battery module composed of at least one battery cell and then constitute the battery pack by using at least one battery module and adding other components.

When connecting the battery cell stack and the bus bars in the battery module, the positions of the bus bars may have a significant influence on the size of the battery module. Further, in the conventional battery module, as the number of the battery cell stages and the battery cells increases, the number of the electrode leads also increases accordingly. Therefore, it is necessary to form the electrode leads and the battery cell platform part to have compact shapes. In addition, the amount of cutting of the electrode lead due to the cutting process of the electrode lead increases, which may result in a cost loss.

Disclosure of Invention

Technical problem

The present disclosure is directed to providing a battery module having an improved welding structure, a method of manufacturing the battery module, and a battery pack including the battery module.

However, the problems to be solved by the embodiments of the present disclosure are not limited to the above-described problems, and various extensions may be made within the scope of the technical idea included in the present disclosure.

Technical scheme

The battery module of the present disclosure may include: a battery cell stack in which a plurality of battery cells are stacked, a bus bar frame connected to the battery cell stack, battery cell lands each protruding from battery cells adjacent to each other among the battery cells included in the battery cell stack, and electrode leads each protruding from the battery cell lands and having the same polarity, wherein the electrode leads may overlap the same bus bar and have at least two welding parts at overlapping portions of the bus bar and the electrode leads.

The electrode leads are formed of N electrode leads, and the N electrode leads overlap the same bus bar, wherein a first welding part where welding is performed between the N electrode leads, and a second welding part where welding is performed between N-1 electrode leads among the N electrode leads and an electrode lead closest to the bus bar is welded to the bus bar may be formed.

The N electrode leads may include a first electrode lead, a second electrode lead, and a third electrode lead, wherein the first electrode lead, the second electrode lead, and the third electrode lead are bent toward the same bus bar, and a bending angle may increase in the order of the first electrode lead, the second electrode lead, and the third electrode lead.

The third electrode lead may overlap the bus bar by a shorter length than the first electrode lead overlaps the bus bar.

The battery cell lands, from which the electrode leads having the same polarity protrude, may have intervals that become narrower along the direction in which the electrode leads protrude.

A method of manufacturing a battery module according to another embodiment of the present disclosure includes the steps of: the method includes forming a battery cell stack by stacking a plurality of battery cells, overlapping electrode leads, each protruding from battery cells adjacent to each other among the battery cells, on the same bus bar, and welding the electrode leads and the bus bar at least two different positions among overlapping portions of the electrode leads and the bus bar.

The welding of the electrode lead and the bus bar may include: a first welding part for welding the electrode leads adjacent to each other and a second welding part for welding the electrode leads adjacent to each other and the bus bar are formed.

The method of manufacturing a battery module may further include: fixing the electrode lead by pressing the electrode lead with a fixing jig before forming the first and second soldering parts.

The fixing jig may have a first opening corresponding to the first welding portion and a second opening corresponding to the second welding portion.

A battery pack according to another embodiment of the present disclosure includes the battery module as described above.

Advantageous effects

According to the embodiment, when welding a plurality of electrode leads, the welded part of the overlapping portions of the bus bar and the electrode leads may be formed of at least two parts, thereby reducing unnecessary increase in the specification of the welding machine and enabling stable management of welding quality.

In addition, cost loss may be minimized by eliminating a cutting process of the electrode leads or reducing the amount of cutting, and a compact battery module structure may be realized by minimizing a gap between the bus bar frame and the battery cell stack.

Drawings

Fig. 1 is a perspective view illustrating a portion of a battery module according to an embodiment of the present disclosure.

Fig. 2 is a sectional view taken along a cutting line a-a' of fig. 1.

Fig. 3 is a plan view schematically illustrating a welding structure of an electrode lead and a bus bar according to a comparative example.

Fig. 4 is a plan view schematically illustrating a welding structure of an electrode lead and a bus bar according to an embodiment of the present disclosure.

Fig. 5 is an enlarged view illustrating a connection relationship between the battery cell terrace portion, the electrode lead, and the bus bar in fig. 1.

Fig. 6 is a plan view illustrating a region P of fig. 5.

Fig. 7 is a front view illustrating a region P of fig. 5.

Detailed Description

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement them. The present disclosure may be modified in various different ways and is not limited to the embodiments set forth herein.

Parts irrelevant to the description will be omitted to clearly describe the present disclosure, and like reference numerals denote like elements throughout the application.

Further, in the drawings, the size and thickness of each element are arbitrarily shown for convenience of description, and the present disclosure is not necessarily limited to those shown in the drawings. In the drawings, the thickness of layers, regions, etc. are exaggerated for clarity. In the drawings, the thickness of some layers and regions are exaggerated for convenience of description.

In addition, it will be understood that when an element such as a layer, film, region or panel is referred to as being "on" or "over" another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" another element, it can be directly on the other element without intervening elements. Further, the words "on … …" or "above … …" mean disposed on or below the reference portion, and do not necessarily mean disposed on the upper end of the reference portion facing the opposite direction of gravity.

Further, throughout this application, when a part is referred to as "including" a certain component, it means that the part may further include other components, without excluding other components, unless otherwise specified.

Further, throughout the application, when referred to as "plane" refers to when the target portion is viewed from the top, and when referred to as "profile" refers to when the target portion is viewed from one side of a cross-section cut perpendicularly.

Fig. 1 is a perspective view illustrating a portion of a battery module according to an embodiment of the present disclosure. Fig. 2 is a sectional view taken along a cutting line a-a' of fig. 1.

Referring to fig. 1 and 2, a battery module 100 according to the present embodiment includes: a module frame 300; a battery cell stack 120 inserted into the module frame 300; and a bus bar frame 130 positioned at an opening side of the module frame 300 and connected to the battery cell stack 120. The battery cell stack 120 is formed by stacking a plurality of battery cells 110 in one direction.

The module frame 300 may be in the form of a single frame covering four surfaces except the front and rear surfaces of the battery cell stack 120. This means that the frame is a form that requires horizontal assembly in order to insert the battery cell stack 120 into the cell frame. However, the module frame 300 is not limited to a single frame, but may be in the form of a frame including a U-shape having an open upper surface, a front surface, and a rear surface, and an upper plate covering the upper portion of the battery cell stack 120.

A battery cell platform 135 extending from a pouch covering the battery cell 110 is formed, and the electrode lead 160 protruding from the battery cell platform 135 may be contacted to pass through a lead groove (not shown). The spacing between adjacent battery cell lands 135 may become narrower as the distance from the battery cell 110 increases. At this time, the electrode leads 160 protruding from the cell platform 135 may have the same polarity. In the case where two electrode leads 160 adjacent to each other have different polarities, the interval between the battery cell stages 135, through which each of the two electrode leads 160 protrudes, may be rather widened as the distance from the battery cell 110 increases.

According to the present embodiment, the compression pads 200 are formed between the outermost battery cells 110 and the side surface portions of the module frame 300. The compression pad 200 may be formed using a polyurethane-based material. The compression pads 200 may absorb the thickness variation of the battery cells 110 due to the swelling of the battery cells 110 and the variation of the battery cells 110 due to external impacts. The at least one compression pad 200 may be formed not only between the outermost battery cell 110 and the side surface portion of the module frame 300, but also between the adjacent battery cells 110.

A path guide 260 is formed on the bus bar frame 130. The path guide 260 is to guide the electrode lead 160 to pass through the lead groove before the battery cell stage 135 extending the electrode lead 160 of each of the three adjacent battery cells 110 is formed, and the path guide 260 may be formed at one side of the bus bar frame 130. Specifically, the bus bar frame 130 may be provided with a path guide 260 inside a rear surface of the bus bar frame 130 disposed spaced apart from the battery cells 110.

Such a path guide 260 may form a predetermined guide space at the rear surface of the bus bar frame 130 so that the three electrode leads 160 and the battery cell platform 135 may be close to each other before passing through the lead groove. A plurality of path guides 260 may be provided. Here, a plurality of path guides 260 may be provided corresponding to the number of the plurality of lead grooves. Accordingly, adjacent electrode leads 160 in the plurality of battery cells 110 are grouped by three, and then the electrode leads 160 may pass through the lead grooves via the path guides 260 to form the groups of electrode leads 160.

The number of the electrode leads 160 forming the group of the electrode leads 160 is not limited to three, and may be modified according to the arrangement of the electrode leads of the positive and negative electrodes of the battery cell 110.

Fig. 3 is a plan view schematically illustrating a welding structure between an electrode lead and a bus bar according to a comparative example. Fig. 4 is a plan view schematically illustrating a welding structure between an electrode lead and a bus bar according to an embodiment of the present disclosure.

Referring to fig. 3, a plurality of electrode leads 160 extend from the battery cell platform 135, and the battery cell platform 135 extends from a pouch covering the battery cell 110. The electrode leads 160 protruding from the battery cell lands 135 may be bent toward the direction in which the bus bars 280 are located. The bent electrode lead 160 overlaps the same bus bar 280, and the bus bar 280 and the plurality of electrode leads 160 are simultaneously welded to form one welding part WP. At this time, in order to simultaneously weld several electrode leads 160, the following limitations arise. First, since the electrode leads 160 overlap, the welder needs a higher specification in order to weld the thickened electrode leads 160. Second, as the number of electrode leads 160 overlapping each other increases, the welder must have a higher specification. Third, as the number of the electrode leads 160 overlapping each other increases, welding deviation of the layers of each electrode lead 160 increases, which may deteriorate welding quality. That is, the layer of the electrode lead 160 closest to the bonding machine may be over-bonded, and the layer of the electrode lead 160 farthest from the bonding machine may be weakly bonded.

Referring to fig. 4, the electrode tab of each battery cell 110 included in the battery module according to an embodiment of the present disclosure is connected with an electrode lead 160. A plurality of electrode leads 160 extend from the battery cell platform 135, and the battery cell platform 135 extends from a pouch that covers the battery cell 110. The electrode leads 160 protruding from the battery cell lands 135 may be bent toward the direction in which the bus bars 280 are located. The bent electrode leads 160 overlap the same bus bar 280, and a plurality of electrode leads 160 may be welded to one bus bar 280. At this time, according to the present embodiment, at least two welding parts WP1 and WP2 are formed in the overlapping portion of one bus bar 280 and the electrode lead 160.

Specifically, according to the present embodiment, the electrode leads are formed of N electrode leads 160, and the N electrode leads 160 may overlap the same bus bar 280. N is a natural number and may be at least 2. The N electrode leads 160 have the same polarity. The bent electrode leads 160 overlap the same bus bar 280, and a plurality of electrode leads 160 may be welded to the bus bar 280 to form a welding part. At this time, the welding part includes at least two welding parts WP1 and WP2, wherein the first welding part WP1 is a part where welding is performed between the N electrode leads 160, and the second welding part WP2 is a part where welding is performed between N-1 electrode leads 160 among the N electrode leads and the electrode lead 160 closest to the bus bar 280 is welded with the bus bar 280.

More specifically, the N electrode leads 160 include a first electrode lead 160a, a second electrode lead 160b, and a third electrode lead 160 c. The first, second, and third electrode leads 160a, 160b, and 160c are bent toward the same bus bar 280, and the bending angles increase in the order of the first, second, and third electrode leads 160a, 160b, and 160 c. In the present embodiment, the length of the third electrode lead 160c overlapping the bus bar 280 is shorter than the length of the first electrode lead 160a overlapping the bus bar 280. Here, the first welding part WP1 is a portion in which the first electrode lead 160a, the second electrode lead 160b, and the third electrode lead 160c are simultaneously welded, or a portion in which the second electrode lead 160b and the third electrode lead 160c are simultaneously welded, and the second welding part WP2 may be a portion in which the first electrode lead 160a, the second electrode lead 160b, and the bus bar 280 are simultaneously welded.

In this way, according to the present embodiment, when welding a plurality of electrode leads 160, by forming at least two welding portions of the overlapping portions of the bus bar 280 and the electrode leads 160, unnecessary increase in the specification of the welding machine can be reduced, and welding quality can be stably managed. In addition, by forming the length of the third electrode lead 160c overlapping the bus bar 280 to be shorter than the length of the first electrode lead 160a, the cutting process of the electrode lead is eliminated or the amount of cutting is reduced, thereby minimizing cost loss, and by minimizing the gap between the bus bar frame and the cell stack, a compact battery module structure can be achieved.

Hereinafter, a method of manufacturing a battery module according to another embodiment of the present disclosure will be described with reference to fig. 5 to 7.

Fig. 5 is an enlarged view illustrating a connection relationship between the battery cell terrace portion, the electrode lead, and the bus bar in fig. 1. Fig. 6 is a plan view illustrating a region P of fig. 5. Fig. 7 is a front view illustrating a region P of fig. 5.

Fig. 5 is a view in which the bus bar frame 130 of fig. 2 is removed.

Referring to fig. 2, 5 and 6, the method of manufacturing a battery module according to the present embodiment includes: forming a battery cell stack 120 by stacking a plurality of battery cells 110; overlapping electrode leads 160, each of which protrudes from the battery cells 110 adjacent to each other among the battery cells 110, on the same bus bar 280; and welding the electrode lead 160 and the bus bar 280 at least two different positions among the overlapping portions of the electrode lead 160 and the bus bar 280.

Referring to fig. 6 and 7, the welding electrode lead 160 and the bus bar 280 may include: a first welding part WP1 for welding the electrode leads 160 adjacent to each other and a second welding part WP2 for welding the electrode leads 160 adjacent to each other and the bus bar 280 are formed. Specifically, as shown in fig. 6, the first welding part WP1 may be formed by simultaneously welding the first electrode lead 160a, the second electrode lead 160b, and the third electrode lead 160c, or by simultaneously welding the second electrode lead 160b and the third electrode lead 160c, and the second welding part WP2 may be formed by simultaneously welding the first electrode lead 160a, the second electrode lead 160b, and the bus bar 280. At this time, electrode lead 160 may be fixed by pressing electrode lead 160 with fixing jig 160FM before forming first weld WP1 and second weld WP 2. As shown in fig. 7, the fixing jig 160FM may have a first opening AP1 corresponding to the first weld WP1 and a second opening AP2 corresponding to the second weld WP 2.

In addition, one or more battery modules according to embodiments of the present disclosure may be packaged in a battery pack case to form a battery pack.

The above battery module and the battery pack including the same may be applied to various devices. These devices may be applied to vehicles such as electric bicycles, electric vehicles, or hybrid vehicles, but the present disclosure is not limited thereto, but may be applied to various devices capable of using a battery module and a battery pack including the battery module, which also falls within the scope of the present disclosure.

Although the preferred embodiments of the present disclosure have been described in detail above, the scope of the present disclosure is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic idea of the present disclosure defined in the following claims also belong to the scope of the claims.

Description of reference numerals

100: battery module

135: battery unit platform part

160: electrode lead

160 FM: fixing clamp

280: bus bar

WP1, WP 2: and (7) welding the parts.