KR20160095740A - Battery Cell Having Through Hole - Google Patents

Abstract

The present invention relates to a battery cell in a plate shape and having an electrode assembly which is chargeable and dischargeable and built in a battery case. The batter cell comprises: the electrode assembly having a cathode, separator, and an anode formed in a lamination layer and a through hole in a central portion thereof and perforated towards the lamination layer; the battery case formed of a lamination sheet including a resin layer and a metal layer and having central openings communicated with the through hole in the electrode assembly and perforated on both surfaces of the battery case and thermosetting sealing units respectively formed along an outer circumference surface of an accommodation unit and an inner surface of the central openings, wherein the electrode assembly is built in the accommodation unit; and a heat conductive ring member attached to the inner surface of the central openings.

Description

A battery cell including a through-hole {Battery Cell Having Through Hole}

The present invention relates to a battery cell including a through-hole.

As technology development and demand for mobile devices are increasing, the demand for secondary batteries as energy sources is rapidly increasing. Among such secondary batteries, many studies have been made on lithium secondary batteries having high energy density and discharge voltage, Widely used.

Generally, a secondary battery includes an electrode assembly composed of a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, which is laminated or wrapped in a battery case of a metal can or a laminate sheet and then injected or impregnated with an electrolyte solution have. The secondary battery having such a configuration includes a cylindrical battery, a prismatic battery, and a pouch-type battery.

Recently, a pouch-shaped battery having a structure in which a stacked or stacked / folded electrode assembly of the above batteries is embedded in a pouch-shaped battery case of an aluminum laminate sheet has been widely used because of its low manufacturing cost, small weight, It is attracting interest and its usage is gradually increasing.

1 is a perspective view schematically showing a typical structure of a typical conventional pouch type secondary battery.

1, the pouch type secondary battery 10 includes an electrode assembly 30, electrode taps 40 and 50 extending from the electrode assembly 30, electrodes 40 and 50 welded to the electrode taps 40 and 50, Leads 60 and 70, and a battery case 20 for housing the electrode assembly 30. [

The electrode assembly 30 is a power generation element in which an anode and a cathode are sequentially stacked with a separation membrane interposed therebetween. The electrode assembly 30 has a stacked or stacked / folded structure. The electrode tabs 40 and 50 extend from each electrode plate 30 of the electrode assembly 30 and the electrode leads 60 and 70 are connected to a plurality of electrode tabs 40 and 50 extending from each electrode plate, Respectively, and a part of the battery case 20 is exposed to the outside. An insulating film 80 is attached to the upper and lower surfaces of the electrode leads 60 and 70 in order to increase the degree of sealing with the battery case 20 and at the same time to ensure an electrically insulated state.

The battery case 20 is made of an aluminum laminate sheet, provides a space for accommodating the electrode assembly 30, and has a pouch shape as a whole. In the case of the stacked electrode assembly 30 as shown in FIG. 1, the battery case 20 is formed so that a plurality of the anode tabs 40 and the plurality of anode tabs 50 can be coupled to the electrode leads 60, The inner top is spaced from the electrode assembly 30.

On the other hand, when an external force is applied to such a battery cell, an internal short circuit may occur due to warping, twisting, or the like of the electrode assembly. Also, when a large amount of heat is generated in the charging and discharging process of the battery cell and the generated heat can not be efficiently removed, heat accumulation may occur, resulting in deterioration of the battery cell. This may cause serious risks such as ignition and explosion in terms of the safety of the battery cell.

Therefore, there is a need for a technique capable of effectively discharging a large amount of heat generated inside the battery cell to solve these problems.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art and the technical problems required from the past.

More specifically, it is an object of the present invention to provide a battery pack that effectively discharges a large amount of heat generated in a battery cell during a charging and discharging process to ensure safety and life of the battery, and even when an external force is applied to the battery cell, And to provide a battery cell capable of preventing an internal short circuit due to development or the like, thereby ensuring safety.

According to an aspect of the present invention, there is provided a battery cell comprising:

An electrode assembly comprising a positive electrode / separator / negative electrode laminated structure and a through hole formed at the center in the stacking direction, the battery assembly comprising: A central opening communicating with the through hole of the electrode assembly is formed on both sides of the electrode assembly, and the electrode assembly is thermally fused along the outer peripheral surface of the receiving portion on which the electrode assembly is mounted and the inner surface of the central opening, A battery case having a sealing portion formed therein; And a thermally conductive ring member mounted in close contact with an inner surface of the central opening.

Therefore, in the battery cell according to the present invention, by inserting the through-hole and the center opening in the center of the battery cell and mounting the thermally conductive ring member on the inner surface of the battery cell, a large amount of heat generated inside the battery cell during the charge- Thereby securing the safety and life of the battery. In addition, even when an external force is applied to the battery cell, internal short-circuiting due to a warping or twisting phenomenon of the electrode assembly can be prevented and safety can be ensured.

As one example of the laminate sheet of the present invention, the laminate sheet has a structure in which a resin layer is coated on both surfaces of the metal barrier layer, and a resin outer layer having excellent durability may be added to one surface (outer surface) And a heat-meltable resin sealant layer may be added to the other surface (inner surface).

Specifically, as the material of the metal barrier layer, aluminum having a blocking property against gas and the like and a softness capable of processing in the form of a thin film can be used. Since the resin outer layer has excellent resistance to external environment, polyethylene terephthalate (PET) and stretched nylon film can be used as a polymer resin having a tensile strength and a weather resistance higher than a predetermined level. Further, as a material of the resin sealant layer, a non-oriented polypropylene film (CPP) film having a low heat absorbing property (heat adhesion property) and low hygroscopicity for suppressing the penetration of an electrolyte solution and not being expanded or eroded by an electrolyte Resin or the like can be used.

The electrode assembly mounted on the battery case housing portion of such a laminate sheet is not particularly limited as long as it is a structure composed of an anode, a cathode, and a separator interposed therebetween. For example, Of the electrode assembly.

As one specific example of the electrode assembly, the electrode assembly may have a square shape or a rectangular shape as viewed from above. In addition, the center of the through-hole may be located within a 30% error range with respect to the plane center of the electrode assembly in the stacking direction of the electrodes based on the length of one side of the square or the length of the short side of the rectangle. That is, the through-hole may be formed in the center of the electrode assembly. When the through-hole deviates greatly from the center of the electrode assembly, it may be difficult to achieve the effect of preventing the electrode assembly from being pushed or twisted when an external force is applied to the battery cell as described above.

Therefore, as the best structure for achieving such an effect, the center of the through-hole may have a structure that coincides with the plane center of the electrode assembly in the electrode stacking direction.

The number of the through grooves is not limited and may be two or more. The shape of the through-hole is not particularly limited, and may be formed in various shapes. For example, a circle, an ellipse, a polygon, a rounded-edge shape, or the like, and may include all shapes closed in a straight line or a curved line.

As the number of the through grooves increases, it is possible to more reliably prevent the electrode assembly from being pushed or twisted when an external force is applied to the battery cell.

The shape of the battery case may also be varied. In one example, the electrode assembly housing part is formed at one side of the unit case. And the other side portion covers the receiving portion in a bent state, and is thermally fused for sealing. Specifically, the battery case has a structure in which an electrode assembly accommodating portion is formed at a predetermined position, and a cover for covering the accommodating portion is formed in a foldable manner. The outer circumferential surface of the other side excluding the folded side is sealed by heat sealing The battery case may be sealed.

In another example, the battery case is formed of two independent members, and the electrode assembly receiving portion is formed on one side or both side members. And the outer circumferential surfaces of the members are thermally fused to each other for sealing.

Meanwhile, the electrode assembly is a power generation device in which an anode and a cathode are sequentially stacked with a separation membrane interposed therebetween. In the manufacturing process, a separation membrane is manufactured to a size somewhat larger than that of an anode and a cathode. Therefore, the separator protrudes to the side of the direction in which the positive electrode / separator / negative electrode are stacked.

In one preferred embodiment, the separator extends in the center of the through-hole in the through-hole formed at the center of the electrode assembly, and the inner surface of the battery case has a heat- And can be thermally fused together with the portion extending in the center direction.

Therefore, not only the outer circumferential surface of the battery case is thermally fused, but also a part of the separation membrane of the electrode assembly is sealed together with the inner surface heat sealing seal portion of the central opening, so that the electrode assembly in the battery case is further fixed, It is possible to prevent a jamming phenomenon caused by application.

As one example of the thermally conductive ring member, the thermally conductive ring member is made of a metal having high thermal conductivity so as to effectively discharge the heat generated in the battery cell, and is mounted on the heat- And may be fixed.

Specifically, the thermally conductive ring member may be formed in two or more corresponding to the through-holes. More specifically, the thermally conductive ring member may be constituted by a first ring mounted on one side of the thermally fused sealing portion of the central opening and a second ring mounted on the opposite side.

The first ring may have a fastening protrusion and the second ring may have a fastening groove corresponding to the fastening hole so that the first ring and the second ring are engaged by the fastening hole and the fastening groove, And can be mounted in the central opening.

The first ring is mounted on one side of the heat sealing portion of the center opening of the battery cell and the second ring is mounted on the other side of the heat sealing portion of the center opening of the battery cell to stably fix the heat sealing portion of the center opening can do.

In addition to the fastening structure, the first ring and the second ring may be structured to be attached to the central opening while being coupled to each other by an adhesive.

In the present invention, the inner diameter of the thermally conductive ring member may be a size of 30 to 90% based on the width of the central opening.

When the inner diameter of the thermally conductive ring member is less than 30% based on the width of the central opening, it is difficult for the thermally conductive ring member to easily be mounted on the central opening, and when the thermally conductive ring member is larger than 90% The desired sealing force can not be exhibited.

The thickness of the thermally conductive ring member may be 50 to 150% based on the thickness of the battery cell.

When the thickness of the thermally conductive ring member is less than 50% of the thickness of the battery cell, it is difficult to efficiently discharge the heat generated in the battery cell. When the thickness of the thermally conductive ring member is thicker than 150% Since a large amount of material must be used for the ring member, there is a problem of an increase in cost.

In addition, the thermally conductive ring member may have a flange part extending from the outer periphery of the central opening to the outer surface of the battery case.

Since the strength of the ring member is higher than the strength of the heat sealable portion when the external force acts on the ring member, the heat sealable sealing member It can be damaged. Therefore, the thermally conductive ring member is formed with the flange portion extending from the outer periphery of the central opening to the outer surface of the battery case, thereby preventing the pushing from the external force and being stably mounted on the battery case.

Further, the present invention provides a battery pack in which the battery cell is mounted in a pack case.

In one example of the pack case, a through-hole of an electrode assembly of a battery cell and a central opening of a battery case are perforated in the pack case, and a flow path through which the coolant flows through the through- Lt; / RTI >

The flow path through which the refrigerant flows effectively dissipates heat generated in the battery cells, thereby securing the safety and life of the battery.

The type of the refrigerant may be a liquid such as water or a gas such as air, and the kind of the refrigerant is not limited as long as it can effectively dissipate heat generated in the battery cell.

The present invention also provides a device comprising the battery cell or the battery pack.

Specific examples of the device include an electric vehicle including an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV) Apparatus, and the like, but is not limited thereto.

As described above, according to the battery cell of the present invention, by inserting the through-hole and the center opening in the center of the battery cell and mounting the thermally conductive ring member on the inner surface of the battery cell, It is possible to effectively discharge the heat and secure the safety and life of the battery. In addition, even when an external force is applied to the battery cell, internal short-circuiting due to a warping or twisting phenomenon of the electrode assembly can be prevented and safety can be ensured.

1 is a perspective view of a typical structure of a typical pouch type secondary battery of the related art;
2 is a perspective view of a battery cell according to one embodiment of the present invention;
Figs. 3 and 4 are respectively a plan view and a side schematic view of Fig. 2; Fig.
5 is a perspective view of a battery cell according to another embodiment of the present invention;
6 is a perspective view of a battery cell according to another embodiment of the present invention;
7 is a perspective view of a battery cell in a state before a thermally conductive ring member is mounted on a heat-sealable sealing part according to an embodiment of the present invention;
8 is a side view of a battery cell in a state before a thermally conductive ring member having a flange portion formed on a heat-sealed sealing portion according to another embodiment of the present invention is mounted;
FIGS. 9 to 11 are schematic diagrams illustrating a manufacturing process of the battery cell of FIG. 1;
12 is a perspective view of a battery pack in which the battery cell of FIG. 1 is mounted.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings, but the present invention is not limited by the scope of the present invention.

2 is a perspective view of a battery cell according to one embodiment of the present invention, and FIGS. 3 and 4 schematically show a plan view and a side view of FIG. 2, respectively.

Referring to these drawings, the battery cell 100 has a central opening 112 formed in a battery case 110 of a laminate sheet including a resin layer and a metal layer, and an electrode The assembly (not shown) also has through holes formed at the center corresponding to the shape of the battery case 110. The detailed structure of the electrode assembly will be described again in Figs. 8 to 10 below.

An outer circumferential surface thermally fused sealing portion 116 is formed on the outer circumferential surface of the storage portion 114 of the battery case 110 on which the electrode assembly is mounted and an inner circumferential surface heat insulating portion 116 is formed along the inner surface of the central opening 112 of the battery case 110. [ And a sealing sealing portion 118 is formed to seal the electrode assembly from the outside.

The electrode assembly housed in the battery case 110 having the central opening 112 is fixed by the central opening 112 to prevent the internal short circuit by suppressing the pushing due to the external impact. In addition, the battery cell 100 has a structure in which a through hole and a central opening 112 are formed, so that the battery cell 100 is also flexible.

The center C of the central opening 112 is located within a 30% error range with respect to the plane center of the electrode assembly in the stacking direction of the electrode with respect to the rectangular short side length L. [ In the drawing, the center C of the central opening 112 and the plane center of the electrode assembly substantially coincide.

5 is a perspective view of a battery cell according to another embodiment of the present invention.

Referring to FIG. 5, the center opening 211 of the battery case 210 and the shape of the hole formed by the through-hole of the electrode assembly have a rough rectangular shape with a gentle corner. The shape of the hole is not particularly limited, and may be formed in various shapes depending on the structure of the battery cell accommodation space of the device such as an ellipse, polygon, or circle as in Fig. 2, and includes a straight or curved closed shape.

5 is the same as the structure of the battery cell of FIG. 2 except that the center opening of the battery case and the structure of the through-hole of the electrode assembly are different from each other, and thus a duplicate description will be omitted.

6 is a perspective view of a battery cell according to another embodiment of the present invention.

Referring to FIG. 6, the openings 311, 312, and 313 of the battery case 310 and the through-holes of the electrode assembly may have a structure of two or more, and are not particularly limited. 6 is the same as the structure of the battery cell of FIG. 2 except for the difference between the center opening of the battery case and the number of through-grooves of the electrode assembly, and thus a duplicate description will be omitted.

FIG. 7 is a perspective view of a battery cell in a state before a thermally conductive ring member is mounted on a heat-sealable portion according to an embodiment of the present invention.

7, the thermally conductive ring members 421 and 422 are fixed in a state of being mounted on the thermally fused sealing portion of the central opening 411 of the battery cell, and the thermally conductive ring members 421 and 422 are fixed in the center A first ring 421 mounted on one side of the heat sealable portion of the opening 411 and a second ring 422 mounted on the opposite side.

(Not shown) protrudes from the first ring 421 and a locking groove (not shown) corresponding to the locking hole (not shown) is formed in the second ring 422, And the first ring 421 and the second ring 422 are attached to the central opening 411 by the engagement of the grooves.

In addition, the first ring 421 and the second ring 422 may be structured to be attached to the central opening 211 while being coupled to each other by an adhesive, in addition to the coupling between the coupling and the coupling groove.

8 is a side view of a battery cell in a state before a thermally conductive ring member having a flange portion is mounted on a heat-sealable sealing portion according to another embodiment of the present invention.

8, the thermally conductive ring members 521 and 522 may have a flange part 531 extending from the outer periphery of the central opening 511 to the outer surface of the battery case.

When the external force acts on the ring members 521 and 522, the ring members 521 and 522 are pressed against the central opening 511 and 522, respectively, when the heat conductive ring members 521 and 522 are mounted on the heat- A flange portion 531 extending from the outer periphery of the battery case 501 to the outer surface of the battery case 501 is formed so that the battery case 501 can be stably mounted on the flange portion 531.

Accordingly, the first ring 521 and the second ring 522 effectively discharge a large amount of heat generated in the battery cell 500 during the charging and discharging process, thereby securing the stability and life of the battery.

FIGS. 9 to 11 are schematic views of the manufacturing process of the battery cell of FIG. 1. FIG.

Referring to these figures, circular through holes 624 are formed in the center of the anode or cathode electrodes 622, and these electrodes 622 are stacked with the separator 626 interposed therebetween Electrode assembly 620 is fabricated. A circular through-hole 624 'is formed in the separation membrane at a smaller area than the through-hole formed in the electrode 622 in order to secure a part of the separation membrane for sealing the portion of the through-hole 624.

The shape of the electrode assembly 620 as viewed from above is rectangular and the center of the through-hole 624 'coincides with the plane center of the electrode assembly 620' in the stacking direction of the electrode 622. However, the structure of the electrode assembly is not particularly limited as shown in the drawing. For example, the center of the through-hole may be 30% of the length of one side of the electrode assembly with respect to the plane center of the electrode assembly in the stacking direction of the electrode But may also be of a structure located within an error range.

2 to 4, the battery case is formed in such a structure that a central opening communicating with the through-hole of the electrode assembly is formed.

The battery case 630 has a structure in which the electrode assembly accommodating portion 634 is formed at one side of the unit and the other side covers the electrode assembly accommodating portion 634 in the bent state. A central opening 632 communicating with the through-hole of the electrode assembly 620 'is formed on one side and the other side.

After the electrode assembly 620 'is mounted on the electrode assembly receiving portion 634 of the battery case 630, one side or the other side of the battery case 630 is folded and the outer side heat sealing sealing portion 636 are thermally fused and sealed. Also, the inner circumferential surface heat sealing sealing portion 638 of the center opening 632 of the battery case 630 is also sealed by heat fusion. At this time, the separation membrane located at the through-groove portion of the electrode assembly 620 'is thermally fused together with the inner circumferential surface heat sealing sealing portion 638 of the central opening so that the electrode assembly 620' is fixed at the central opening 632 . Therefore, the electrode assembly 620 'is prevented from being pushed in the battery case 630 when an external force is applied.

12 is a perspective view of a battery pack in which the battery cell of FIG. 1 is mounted. Referring to FIG. 12, the pack case 710 of the battery pack 700 is formed with a through-hole 711 communicating with the electrode assembly of the battery cell and the center opening of the battery case.

When the battery pack 700 having the through holes 711 formed thereon is stacked to constitute the battery module 700, the battery pack 700 And the flow path through which the coolant flows through the through grooves of the battery cells is formed, so that a large amount of heat generated during the charging and discharging process can be easily discharged.

The type of the refrigerant may be a liquid such as water or a gas such as air, and the kind of the refrigerant is not limited as long as it can effectively dissipate heat generated in the battery cell.

Those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims (22)

A battery cell having a plate-like shape in which an electrode assembly capable of charging and discharging is embedded in a battery case,
An electrode assembly having a positive electrode / separator / negative electrode laminated structure and a through hole formed at the center in the stacking direction;
A central opening communicating with the through hole of the electrode assembly is formed on both sides of the electrode assembly, and the electrode assembly is thermally fused along the outer peripheral surface of the receiving portion on which the electrode assembly is mounted and the inner surface of the central opening, A battery case having a sealing portion formed therein; And
A thermally conductive ring member mounted in close contact with an inner surface of the central opening;
The battery cell comprising: The battery cell according to claim 1, wherein the electrode assembly comprises a wound-type structure, a stacked structure, or a stack / folding structure. The electrode assembly according to claim 1, wherein the electrode assembly has a square or rectangular shape as viewed from above, and the center of the through-hole has a length of one side of the square or a short side of the rectangle relative to the center of the plane of the electrode assembly in the stacking direction of the electrodes Is within a 30% error range. The battery cell according to claim 3, wherein the center of the through-hole coincides with the plane center of the electrode assembly in the stacking direction of the electrodes. The battery cell according to claim 1, wherein the through-hole has a circular shape, an elliptical shape, or a polygonal shape as viewed from above. The battery cell according to claim 1, wherein at least two through-holes are formed. The battery case according to claim 1, wherein the battery case is formed as a single unit and has an electrode assembly storage part formed at one side thereof. And the other portion covers the housing portion in a bent state, and is thermally fused for sealing. The battery case according to claim 1, wherein the battery case is formed of two independent members, and the electrode assembly receiving part is formed on one side or both sides of the case. And the outer circumferential surfaces of the members are thermally fused for sealing. The battery cell according to claim 1, wherein the inner surface thermally fused sealing portion of the central opening is thermally fused together with the separation membrane of the electrode assembly. The battery cell according to claim 1, wherein the thermally conductive ring member is fixed in a state of being mounted on a thermally fused sealing portion of the central opening. The battery cell according to claim 1, wherein the thermally conductive ring member is formed in two or more corresponding to the through-holes. The battery cell according to claim 1, wherein the thermally conductive ring member is composed of a first ring mounted on one side of the heat sealable portion of the center opening and a second ring mounted on the opposite side. 13. The connector according to claim 12, wherein a fastener is protruded from the first ring, and a fastening groove corresponding to the fastening hole is formed in the second ring, Is mounted on the center opening. 13. The battery cell according to claim 12, wherein the first ring and the second ring are coupled to each other by an adhesive, and are mounted to the central opening. The battery cell according to claim 1, wherein the thermally conductive ring member is made of a metal material. The battery cell according to claim 1, wherein the inner diameter of the thermally conductive ring member is 30 to 90% of the width of the central opening. The battery cell according to claim 1, wherein the thickness of the thermally conductive ring member is 50 to 150% of the thickness of the battery cell. The battery cell according to claim 1, wherein the thermally conductive ring member has a flange part extending from an outer periphery of the central opening to an outer surface of the battery case. A battery pack according to claim 1, wherein the battery cell is mounted on a pack case. The battery pack according to claim 19, wherein a flow path through which the coolant flows through the through-hole of the battery cell is formed. 20. A device comprising a battery pack according to claim 19. 22. The device of claim 21, wherein the device is an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or a power storage device.

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