KR102695311B1 - Battery module - Google Patents

Abstract

One embodiment of the present invention relates to a battery module. According to one embodiment of the present invention, a battery module can be provided, including: a plurality of battery cells, each of which includes an electrode tab; a bus bar connected to the electrode tabs for electrically connecting at least a portion of the plurality of battery cells to each other; and a support plate positioned between the plurality of battery cells and the bus bar; wherein at least a portion of the support plate is formed of a ceramic for a thermoelectric cooling element.

Description

Battery Module{BATTERY MODULE}

Embodiments of the present invention relate to a battery module.

Secondary batteries that can be recharged and discharged are being actively studied due to the development of cutting-edge fields such as digital cameras, cell phones, laptops, and hybrid cars. Secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-hydrogen batteries, and lithium secondary batteries. Among these, lithium secondary batteries have an operating voltage of 3.6 V or higher and are used as power supplies for portable electronic devices, or are connected in series to be used in high-power hybrid cars. Compared to nickel-cadmium batteries or nickel-metal hydride batteries, their operating voltage is three times higher and their energy density per unit weight is also superior, so they are being used rapidly.

In the case of a conventional battery module, a bus bar is used to connect the electrode tabs between the secondary batteries within the battery module, and in order to insulate the bus bar from other elements within the battery module, there are cases where a structure is used in which an injection-molded material for supporting the bus bar is positioned between the bus bar and the battery cells of the secondary battery. The injection-molded material uses engineering plastic to increase insulation, and in the case of such an injection-molded material, it has a thermal conductivity of 2 to 3 W/mK. When the battery module is used, heat is generated in the battery cells of the secondary battery, and if this heat generation is not resolved, problems occur with the battery performance and lifespan.

However, in the case of a conventional battery module, the heat generated in the secondary battery is transferred to the bus bar connected to the electrode tab, but since the injection-molded material in contact with the bus bar does not have sufficient thermal conductivity, little heat is transferred to the injection-molded material, and it becomes difficult for heat to be transferred from the bus bar to the other side. A cooling means using a refrigerant comes into contact with the external case of the battery module to cool the battery module, but since the bus bar and the external case cannot come into contact for insulation, the heat transferred to the bus bar cannot directly reach the external case. Accordingly, the heat from the bus bar can only be naturally released into the air inside, and the heat transferred to the bus bar cannot be efficiently cooled by the cooling means in contact with the external case.

Korean Patent Publication No. 10-2015-0110078 (October 2, 2015)

Embodiments of the present invention are directed to providing a battery module capable of effectively cooling the heat generation of a secondary battery.

Additionally, it is to provide a battery module forming a heat transfer path between the secondary battery and the module case.

According to one embodiment of the present invention, a battery module may be provided, including: a plurality of battery cells, each of which includes an electrode tab; a bus bar connected to the electrode tabs for electrically connecting at least a portion of the plurality of battery cells to each other; and a support plate positioned between the plurality of battery cells and the bus bar; wherein at least a portion of the support plate is formed of a ceramic for a thermoelectric cooling element.

The battery module may further include a module case positioned at least on a portion of the exterior of the battery module.

Contact can be made between the above support plate and the module case.

A cooling member may be brought into contact with one of the upper and lower sides of the module case.

The interior of the above cooling member may contain a refrigerant.

A cooling member may be brought into contact with each of the upper and lower sides of the module case.

Heat generated from the above battery cell can sequentially move along the electrode tab, the bus bar, the support plate, and the module case.

The ceramic for the above thermoelectric cooling element can be selected from Al ₂ O ₃ , AlN, and Si ₃ N ₄ .

The bus bar includes a plate having a plurality of holes formed therein, and the electrode tabs are inserted into at least some of the plurality of holes of the plate so that the plurality of battery cells can be electrically connected to each other.

The connection between the above electrode tab and the above plate may have a wobble weld shape by laser welding.

The above support plate may be formed with a plurality of support holes corresponding to the plurality of holes of the plate.

According to an embodiment of the present invention, a battery module capable of effectively cooling the heat generation of a secondary battery can be provided.

Additionally, a battery module forming a heat transfer path between a secondary battery and a module case can be provided.

Figure 1 is a drawing showing a secondary battery according to one embodiment of the present invention.
Figure 2 is an exploded perspective view showing the arrangement of a bus bar, a support plate, and a fixed plate according to one embodiment of the present invention.
FIG. 3 is a drawing showing a battery module according to one embodiment of the present invention.
Figure 4 is a cross-sectional view showing the heat transfer state of a battery module according to one embodiment of the present invention.
Figure 5 is a cross-sectional view showing the heat transfer state of a battery module according to another embodiment of the present invention.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. However, these are merely examples and the present invention is not limited thereto.

In explaining the present invention, if it is judged that a detailed description of a known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description will be omitted. In addition, the terms described below are terms defined in consideration of their functions in the present invention, and these may vary depending on the intention or custom of the user or operator. Therefore, the definitions should be made based on the contents throughout this specification.

The technical idea of the present invention is determined by the scope of the claims, and the following examples are merely a means for efficiently explaining the technical idea of the present invention to a person having ordinary knowledge in the technical field to which the present invention belongs.

FIG. 1 is a drawing showing a secondary battery (10) according to one embodiment of the present invention, and FIG. 2 is an exploded perspective view showing the arrangement of a bus bar (20), a support plate (30), and a fixing plate (40) according to one embodiment of the present invention.

Referring to FIGS. 1 and 2, the secondary battery (10) may be formed with a battery cell (11) and an electrode tab (12). An insulating portion (12a) capable of securing an electrical insulation state may be formed at a location where the electrode tab (12) is withdrawn. The bus bar (20) has a shape in which a hole (23) is formed in a plate (21). A plurality of holes (23) are formed, and an electrode tab (12) is welded to each hole (23), so that a plurality of welded battery cells (11) may be electrically connected. In this case, the welding between the hole (23) of the plate (21) and the electrode tab (12) may be laser welding having a wobble welding shape. A plurality of holes (23) may be formed in the plate (21) to correspond to the number of battery cells (11) to be connected. According to Fig. 1(b), which is an enlarged version of Fig. 1(a), a chamfer portion (125) is formed on both ends of the electrode tab (12), so that the electrode tab (12) can be easily inserted into the hole (23) of the electrode tab (12).

Specifically, the edges of the electrode tab (12) in the longitudinal direction (d ₂ ) of the end face of the electrode tab (12) may be formed by being cut obliquely with respect to the longitudinal direction (d ₁ ) of the electrode tab (12), and a chamfered portion (125) may be formed on both ends of the electrode tab (12). As described above, by forming the chamfered portion (125) at the end of the electrode tab (12), the insertion of the electrode tab (12) into the hole (23) can be induced during the hole insertion process, and the insertion of the electrode tab (12) can be made easier.

A battery module (reference numeral 1 in FIG. 3) according to one embodiment of the present invention may further include a support plate (30) having a plurality of support holes (32) formed therein corresponding to the holes (23) of the bus bar (20). At this time, the support plate (30) may be positioned between a plurality of battery cells (11) and the bus bar (20) to fixally support the bus bar (20).

Specifically, the support plate (30) may include a plate-shaped support plate body (31) and a plurality of support holes (32) formed on the support plate body (31) to correspond to the plurality of holes (23) of the bus bar (20). At this time, the size of the support hole (32) may be formed to have a wider cross-section than the size of the bus bar hole (23).

Through this, the gap between the electrode tab (12) and the bus bar hole (23) is kept constant during the welding process, and the position of the electrode tab (12) inserted into the hole (23) is fixed, so that the welding line can be easily traced when welding the electrode tab (12) later.

Meanwhile, the support plate may have an insulating material coated on its outer surface or may be formed of an insulating material, and each of the plurality of electrode tabs may be fixed while being inserted into each of the plurality of support holes, thereby maintaining an insulating state between the electrode tabs.

Furthermore, the battery module (1) according to one embodiment of the present invention may further include a fixing plate (40) that securely supports the bus bar (20) and the support plate (30) by connecting them.

Specifically, the battery module (1) according to one embodiment of the present invention may further include a fixed plate (40) having a plurality of busbar exposure holes (42) formed corresponding to the holes (23) of the busbar (20). At this time, the fixed plate (40) is positioned on the outer side of the busbar (20) and is coupled with at least a part of the support plate (30) at least partially to thereby fix and support the busbar (20). In addition, the fixed plate (40) may be positioned in a shape that covers the outer surface of the busbar (20), thereby protecting the busbar (20) from external foreign substances, etc.

More specifically, the fixed plate (40) may include a plate-shaped fixed plate body (41) and a plurality of busbar exposure holes (42) formed on the fixed plate body (41) to correspond to the plurality of holes (23) of the busbar (20). At this time, the size of the busbar exposure hole (42) may be formed to have a wider cross-section than the size of the busbar hole (23).

In addition, the fixed plate (40) can be formed in a form that surrounds the outer surface of the plate (21) of the busbar (20) except for the busbar exposure hole (42), and can stably support and fix the busbar (20) by connecting the support plate (30) and the busbar (20) with each other.

Meanwhile, a terminal support hole (44) may be formed at a position corresponding to the terminal portion (25) at at least a portion of both ends of the fixed plate (40), and the terminal portion (25) may be inserted into and fixed in the terminal support hole (44).

For example, a terminal portion (25) may be formed on at least a portion of each of the two bus bars (20) located at both ends on one side of the battery module (1). Further, as shown in FIG. 2, the terminal portion (25) may be inserted into a terminal support hole (44) formed on a fixed plate (40), thereby fixing and supporting the position of the bus bar (20).

Furthermore, since the terminal portion (25) protrudes outside the fixed plate (40), even when the bus bar (20) is wrapped around the fixed plate (40), the terminal portion (25) can be exposed outside the fixed plate (40) and connected to an external battery module or charging/discharging device.

Meanwhile, as described above, in the case where a plurality of bus bars (20) are provided, at least one fixing member (43) may be formed on at least a portion of the fixed plate (40) so as to be positioned between the plurality of bus bars (20) and to fix and support the position of the bus bars (20). At this time, the at least one fixing member (43) may be formed to protrude from at least a portion of the fixed plate body (41) toward the bus bars (20), and may be formed corresponding to the number of bus bars (20). For example, as illustrated in FIG. 2, in the case where two bus bars (20) are provided, one fixing member (43) may be formed on one side of the fixed plate (40), and the fixing member (43) may be positioned between the two bus bars (20) to fix and support the position of the bus bars (20).

In addition, a fixing member insertion groove (33) corresponding to the fixing member (43) may be formed by being inserted into at least a portion of the bus bar (20) side of the support plate (30). Specifically, a fixing member (43) protruding from the fixing plate (40) may be inserted into one side of the support plate (30), and the bus bar (20) may be more firmly fixed and supported by the fixing member (43) being positioned in the fixing member insertion groove (33).

Furthermore, the fixed plate (40) may include a plurality of fastening projections (411) formed so that at least a portion of the fixed plate body (41) protrudes toward the bus bar (20), and the support plate (30) and the fixed plate (40) may be mutually fastened by the fastening projections (411) being coupled with at least a portion of the support plate (30).

Specifically, a catch (not shown) is formed on the fastening projection (411), and a catch groove (not shown) corresponding to the catch is formed on at least a portion of the support plate (30), so that the fixed plate (40) and the support plate (30) can be mutually fastened and combined with the bus bar (20) interposed therebetween by fastening the catch and the catch groove. However, this is merely exemplary and is not limited thereto, and it is sufficient if the fastening projection (411) can be fastened and combined by contacting at least a portion of the support plate (30).

Meanwhile, at least one insertion projection (45) protruding toward the bus bar (20) may be formed on the side of the fixed plate body (41) on the bus bar (20). At this time, the bus bar (20) may further include at least one through hole (26a) formed at a position corresponding to the position of the insertion projection (45) on the plate (21) and penetrated by the insertion projection (45). In addition, the support plate (30) may further include at least one fastening hole (34) formed on the support plate body (31) into which the insertion projection (45) can be inserted and which can be combined with the insertion projection (45) in an inserted state of the insertion projection (45).

Specifically, the insertion projection (45), the through hole (26) and the fastening hole (34) may be formed at positions corresponding to each other in the fixed plate body (41), the plate (21) and the support plate body (31), respectively. For example, the insertion projection (45) may be formed at a position adjacent to the bus bar exposure hole (42), and correspondingly, the through hole (26) may be formed at a position adjacent to the hole (23), and the fastening hole (34) may be formed at a position adjacent to the support hole (32).

More specifically, as shown in FIG. 2, when the fixed plate (40), the bus bar (20), and the support plate (30) are combined, the insertion projection (45) can be inserted into the fastening hole (34) of the support plate (30) by penetrating the through hole (26) of the bus bar (20). At this time, the insertion projection (45) inserted into the fastening hole (34) and the fastening hole (34) are mutually combined, thereby allowing the support plate (30) and the fixed plate (40) to be combined, and the position of the bus bar (20) can be fixed.

In addition, when the insertion protrusion (45) is inserted into the fastening hole (34) through the through hole (26), the insertion protrusion (45) can be attached to one surface of the support plate body (31) by heat fusion, and through this, the fixed plate (40), the bus bar (20), and the support plate (30) are mutually fastened, so that the position of the bus bar (20) can be stably fixed and supported.

Meanwhile, the support plate (30) and the fixed plate (40) can be formed to a size corresponding to the cross-sectional area in the stacking direction of a plurality of battery cells (11). Through this, despite the volume of the support plate (30) and the fixed plate (40), the unnecessary volume of the battery module (1) can be minimized, and the bus bar (20) and the electrode tab (12) can be fixedly supported within a range that does not hinder the energy density of the battery module (1).

However, below, the bus bar (20) and the support plate (30) will be mainly described, and the fixed plate (40) will be omitted.

FIG. 3 is a drawing showing a battery module (1) according to one embodiment of the present invention.

Referring to FIG. 3, a battery module (1) according to one embodiment of the present invention may include a module case (50) that accommodates a plurality of secondary batteries (10) stacked on top of each other and is formed of a material with high thermal conductivity to cool the secondary batteries (10), and front and rear cover parts (60a, 60b) that are arranged at the outermost front and rear sides of the secondary batteries (10) and protect and fix the secondary batteries (10) inside by being combined with the module case (50).

As described above, the battery module (1) according to one embodiment of the present invention can be protected from external impact or foreign substances by the module case (20) and front and rear cover parts (60a, 60b), and the strength and rigidity can be reinforced to improve the assembling ability.

Meanwhile, the module case (50) can be formed so as to surround the surfaces from which the electrode tabs (12) are not withdrawn in the battery group (10). The module case (50) is formed with a structure that surrounds the four sides of the stacked secondary battery (10), thereby supporting and protecting the stacked secondary battery (10).

In addition, the module case (50) can be formed of a material with high thermal conductivity, thereby performing the function of discharging heat generated from the secondary battery (10) to the outside. In addition, the module case (50) can be formed of an aluminum (AL) material.

Figure 4 is a cross-sectional view showing the heat transfer state of a battery module (1) according to one embodiment of the present invention.

Referring to FIG. 4, an electrode tab (12) included in a secondary battery (10) in a battery module (1) may be connected to a bus bar (20) by welding through a support plate (30). Accordingly, heat generated inside the secondary battery (10) may be transferred to the electrode tab (12) and may be transferred to the bus bar (20) connected to the electrode tab (12). In one embodiment of the present invention, in order to allow the heat transferred to the bus bar (20) to be cooled through a cooling member (200) in contact with the outside of the module case (50), a heat transfer path may be formed from the bus bar (20) to the module case (50). To this end, the support plate (30) in contact with the bus bar (20) can be formed of a thermoelectric cooling element ceramic instead of plastic, so that the heat of the secondary battery (10) transferred to the bus bar (20) can be transferred to the module case (50) through the support plate (30). By maintaining the support plate (30) and the module case (50) in contact, a heat transfer path between the support plate (30) and the module case (50) is formed, and by forming the support plate (30) of a thermoelectric cooling element ceramic with high thermal conductivity, the heat can be properly transferred along the path.

Ceramics for thermoelectric cooling elements for forming the support plate (30) can be selected from among Al ₂ O ₃ , AlN, and Si ₃ N ₄ . Table 1 below shows the characteristics of each ceramic for thermoelectric cooling elements.

subject matter
characteristic Al ₂ O ₃ AlN Si ₃ N ₄ Thermal Conductivity (W/mK) 20-30 70-250 60-90 Insulation strength (kV/mm) >12 >14 >14 dielectric constant 9-10 9 7-9

As shown in Table 1 above, since each ceramic for thermoelectric cooling elements has high thermal conductivity, when used as a material for the support plate (30), it can be effective in transferring heat between the bus bar (20) and the module case (50).

In addition, since the support plate (30) is located between the bus bar (20) and the secondary battery (10), insulation is important. In the case of a ceramic for a thermoelectric cooling element, sufficient insulation can be secured, so it may be suitable for use as the support plate (30).

In the present embodiment, a cooling member (200) including a refrigerant (not shown) therein may be in contact with one side of the lower case (50a) and the upper case (50b) among the module cases (50). Although FIG. 4 illustrates that the cooling member (200) is in contact with the lower case (50a), the cooling member (200) may also be in contact with the upper case (50b). The heat of the secondary battery (10) transferred to the module case (200) is cooled through the cooling member (200), so that heat generation within the battery module (1) can be controlled, thereby maintaining the performance of the battery module (1).

Fig. 5 is a cross-sectional view showing the heat transfer state of a battery module (1a) according to another embodiment of the present invention. Descriptions of parts overlapping with those of the embodiment of Fig. 4 in the description of the embodiment of Fig. 5 are omitted.

Referring to FIG. 5, in the present embodiment as well, heat generated from the secondary battery (10) can be transferred through the bus bar (20), the support plate (30), and the module case (50). However, in the present embodiment, cooling members (200a, 200b) can be in contact with both sides of the lower case (50a) and the upper case (50b) of the module case (50). Accordingly, heat generated from the secondary battery (10) is transferred to both sides of the lower case (50a) and the upper case (50b) of the module case (50) and is cooled by the cooling members (200a, 200b) in contact with both sides, so that the cooling efficiency of heat generated from the battery module (1) can be further increased.

Although representative embodiments of the present invention have been described in detail above, those skilled in the art will understand that various modifications can be made to the above-described embodiments without departing from the scope of the present invention. Therefore, the scope of the rights of the present invention should not be limited to the described embodiments, but should be determined not only by the claims described below but also by equivalents of the claims.

1, 1a : Battery module
10: Secondary battery
11: Battery cell
12: Electrode tab
12a : Insulation
125 : Champerbu
20 : Bus bar
21 : Plate
23 : Hall
24: Busbar auxiliary parts
25 : Terminal section
26 : Through hole
30 : Support plate
31: Support plate body
32 : Support hole
33: Fixed member insertion groove
34 : Fastening hole
40 : Fixed plate
41: Fixed plate body
411 : Fastening protrusion
42: Busbar exposure hole
43 : Fixed member
44 : Terminal support hole
45 : Insertion protrusion

Claims (11)

A plurality of battery cells, each comprising an electrode tab;
a bus bar connected to the electrode tabs to electrically connect at least a portion of the plurality of battery cells to each other; and
A support plate positioned between the plurality of battery cells and the bus bar;
A battery module, wherein at least a portion of the support plate is formed of a ceramic for a thermoelectric cooling element.
In claim 1,
A battery module further comprising a module case positioned at least on a portion of an outer side of the battery module.
In claim 2,
A battery module in which contact is made between the support plate and the module case.
In claim 3,
A battery module in which a cooling member comes into contact with one of the upper and lower sides of the module case.
In claim 4,
A battery module containing a refrigerant inside the above cooling member.
In claim 3,
A battery module in which a cooling member is in contact with each of the upper and lower sides of the module case.
In claim 2,
A battery module, wherein heat generated from the battery cell moves sequentially along the electrode tab, the bus bar, the support plate, and the module case.
In claim 7,
A battery module in which the ceramic for the thermoelectric cooling element is selected from among Al ₂ O ₃ , AlN, and Si ₃ N ₄ .
In claim 1,
The above bus bar includes a plate in which a plurality of holes are formed,
A battery module, wherein the electrode tabs are inserted into at least some of the plurality of holes of the plate so that the plurality of battery cells are electrically connected to each other.
In claim 9,
A battery module, wherein the connection between the electrode tab and the plate has a wobble weld shape by laser welding.
In claim 9,
A battery module, wherein the support plate has a plurality of support holes formed corresponding to the plurality of holes of the plate.