KR100648720B1 - Case for secondary battery and, secondary battery and secondary battery module using the same - Google Patents

Abstract

The present invention is to minimize the volume of the secondary battery module to improve the cooling efficiency of at least one side of the outer surface of the case forming the inner side to form a recessed unit cells and the unit cells and the unit cells are stacked and cooled inside Provided is a secondary battery module including a housing in which a medium is distributed.

Secondary Battery, Secondary Battery Module, Cooling Efficiency, Case

Description

Case of secondary battery, secondary battery and secondary battery module using same {CASE FOR SECONDARY BATTERY AND, SECONDARY BATTERY AND SECONDARY BATTERY MODULE USING THE SAME}

1 is a cross-sectional view of a rechargeable battery according to an exemplary embodiment of the present invention.

2A to 2B are perspective views of a rechargeable battery according to another embodiment of the present invention.

3A to 3B are perspective views of a rechargeable battery according to still another embodiment of the present invention.

4 is a plan view of a rechargeable battery module according to an exemplary embodiment of the present invention.

5A to 5C are perspective views illustrating a rod member of a rechargeable battery module according to an embodiment of the present invention and another embodiment.

The present invention relates to a secondary battery and a secondary battery module, and more particularly, to a case of a secondary battery having an improved form.

Recently, a high output secondary battery using a high energy density nonaqueous electrolyte has been developed, and a plurality of high output secondary batteries can be connected in series so as to be used for driving a motor such as an electric vehicle requiring a large power. The secondary battery is configured.

The secondary batteries are manufactured in various shapes, and typical shapes include cylindrical shapes and square shapes, and one large capacity secondary battery (hereinafter, referred to as a battery module for convenience of description throughout) is usually connected in series. It consists of a plurality of secondary batteries (hereinafter referred to as unit cells for convenience of explanation throughout the specification).

Each unit cell includes an electrode assembly in which a positive electrode plate and a negative electrode plate are positioned with a separator interposed therebetween, a case having a space in which the electrode assembly is embedded, a cap assembly coupled to the case and sealing the protruding portion from the cap assembly. And positive and negative terminals electrically connected to the positive and negative current collectors provided in the electrode assembly.

Each unit cell is arranged in a row, and a battery module is constructed by connecting and installing a conductor between nuts through a screwed negative electrode terminal and a positive electrode terminal.

However, each unit cell generates heat internally at the time of operation, and in the case of the battery module composed of a plurality of unit cells, it is possible to smoothly perform the function only when it is possible to easily release heat generated.

As described above, in order to dissipate heat in the battery module, a conventional battery module arranges several unit cells side by side in a housing, and installs battery partition walls having passages through which refrigerant flows between the unit cells, thereby providing a refrigerant between the partition walls. The unit cell is cooled so that the unit cell is cooled and the gap between the unit cells is maintained.

However, in the case of the structure in which the partition is inserted between the unit cells, the barrier rib is newly manufactured, and thus a cost is additionally generated, and the volume of the battery module is increased due to the size of the barrier rib.

When the volume of the battery module increases, not only the weight of the battery module itself increases, but also a device in which the battery module is mounted, especially a HEV vehicle, becomes difficult to design.

In addition, when heat is not released properly, for example, heat generated in each unit cell causes an increase in the temperature of the battery module, resulting in a malfunction of the device to which the battery module is applied.

Therefore, the development of a battery module that can improve the heat dissipation characteristics while minimizing the size of the battery module in the case of a secondary battery that requires a large capacity, such as for HEV.

In addition, when the protection circuit does not operate normally or an unexpected abnormal reaction occurs while the battery is in use, gas is generated according to a chemical reaction inside the battery. In the case of a conventional unit cell, there is not enough space to accommodate the gas. Since the pressure rises inside the battery, a swelling phenomenon in which the battery case swells may occur.

In addition, due to the swelling phenomenon, the battery case may be expanded to press the fasteners for fixing the unit cells in the battery module, thereby causing the fastener to be damaged. In serious cases, the unit battery may explode.

In addition, even if the vent is installed to discharge gas under a predetermined pressure condition as in the prior art, the battery cannot be recovered once the vent is opened. Therefore, the battery must be discarded. There is a problem that is shortened.

Therefore, the present invention has been made to solve the above problems, an object of the present invention is to improve the structure of the case of the secondary battery to form a flow path of the refrigerant without a partition wall to minimize the volume of the secondary battery module It is to provide a secondary battery module.

In addition, the present invention provides a secondary battery, a secondary battery case and a secondary battery module that can prevent a swelling phenomenon by securing a free space inside the unit battery.

In order to achieve the above object, the unit cell of the present invention has a structure in which at least one of the outer surfaces of the case is recessed.

The unit cell may include an electrode assembly including a separator and a cathode plate and a cathode plate disposed on both sides of the separator, a case in which the electrode assembly is embedded and at least one side of the outer surface is recessed, and a cap coupled to and sealing the case. It may comprise an assembly.

The cap assembly may include a cap plate provided with an electrode terminal, and the cap plate may include a vent that is opened at a constant pressure at a center thereof to prevent gas from being generated and deformation of the case due to a swelling phenomenon. .

The case has a concave recessed shape, the width of the opening in the central portion is sufficient to the extent that the electrode assembly can be built.

In addition, the cross-sectional shape of the concave portion may be formed in an arc shape, it may be formed in the same cross-sectional shape in the height direction of the case.

In addition, the structure of the battery case may have a support portion formed at both ends of the case to secure the rigidity of the case and may be recessed between the support portions to form a concave portion, and also may be a structure embedded in the center from both ends of the case have.

In addition, in order to maintain the shape of the concave portion, the thickness of the plate constituting the case may be increased, or when the unit cell constitutes the battery module, the rod member may be inserted between the cells to support the internal pressure of the unit cell. have.

On the other hand, the present invention is arranged to cross each unit cell, and between the screwed negative terminal and the positive terminal connected to the conductor via a nut to install a battery module.

The battery module may have a refrigerant flow passage formed between unit cells according to a shape of a battery case, and a rod member may be inserted into the refrigerant flow passage.

In addition, an insulating member may be inserted into a portion where the unit cells contact each other to secure insulation between the unit cells.

In addition, the secondary battery may be used as an energy source for driving a motor of the device in a device that operates using a motor, such as a hybrid electric vehicle (HEV), an electric vehicle (EV), a wireless cleaner, an electric bicycle, an electric scooter, and the like. Can be.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view of a rechargeable battery according to an exemplary embodiment of the present invention.

Looking at the structure of each unit cell 10 constituting a large-capacity battery module with reference to the above drawings, the unit cell 10 is the positive electrode plate 11 and the negative electrode plate 12 positioned between the separator 13 A case 20 having an electrode assembly 14, a space part in which the electrode assembly 14 is embedded, a cap assembly 30 coupled to the case 20 and sealing the cap assembly 30, the positive and negative electrode plates 11, And positive and negative terminals 31 and 32 electrically connected to the current collector of 12) and protruding outside the cap assembly 30.

In this case, the cap assembly 30 may include a vent 34 that opens under a constant pressure condition in preparation for excessive gas increase due to gas generation.

In addition, the case 20 is made of a conductive metal such as aluminum, aluminum alloy or nickel plated steel, and the shape is made of a cube or other shape having a cube having an inner space in which the electrode assembly 14 is located. .

As shown in FIG. 2, the case 20 is formed at both ends to have a predetermined length in a straight line, and has a support portion contacting the neighboring unit cells 10, and the support portion 21 is recessed toward the center. The recessed part 22 is formed.

The recess 22 is formed on at least one surface of the front and rear of the case 20, preferably formed on both sides can maximize the cooling efficiency.

In addition, the concave portion 22 may be embedded in a straight line toward the center, or may be embedded in various forms, such as to form a parabolic curve gently, preferably arc to support the external force uniformly It may be incorporated into a shape.

The cross-sectional shape of the recessed portion 22 is formed to be the same in the height direction of the case 20.

The support part 21 is a part which is not embedded in the case, and serves to support the unit cells 10 to be stacked when the unit cell 10 forms the battery module 40 as well as inside the battery. It can function as a space to accommodate increasing volume when gas is generated.

Therefore, the length of the support part 21 may be formed to an appropriate length to sufficiently maintain the structure in which the unit cells 10 are stacked in the battery module 40 and to sufficiently secure the flow passage 41 of the refrigerant.

In addition, the thickness of the plate 20 of the case 20 is sufficiently high that the shape of the recess 22 is not deformed by the external environment when the pressure inside the unit cell 10 increases or when the battery module 40 is configured. Can become thick.

In addition, the recess 22 is most embedded in the center portion of the case 20, the width of the case 20 in the center portion is formed to a width enough to insert the electrode assembly 14 do.

2A illustrates a unit cell 10 having recesses 22 formed on both front and rear surfaces of the case 20. In this embodiment, the area of the refrigerant flow passage increases as the center of the case 20 increases. Therefore, it is the structure that can maximize the cooling efficiency in the central part with the most heat generation.

FIG. 2B illustrates a unit cell 10 having recesses 22 formed on the front surface of the case 20. In this embodiment, the refrigerant flow passage 41 is formed while minimizing the volume of the battery module 40. The area of the refrigerant flow passage can be enlarged or reduced by adjusting the arc-shaped curvature radius of the recess 22.

3 illustrates a unit cell 10 according to another embodiment of the present invention, in which one surface of the case 20 does not include the support portion 21 and is recessed in an arc shape at both ends of the case 20. Concave portion 22 is formed in the structure of FIG.

The structure of the unit cell 10 when the battery module 40 is configured, the side surface of the case 20 serves to support the laminated structure, by increasing the area to be embedded to ensure the maximum flow path of the refrigerant Cooling efficiency can be maximized.

4 illustrates a battery module 40 according to an embodiment of the present invention, in which the unit cells 10 are stacked in a line, and the case is recessed between the unit cells 40. Due to the shape of the portion 22, a passage 41 through which the refrigerant can flow is formed.

The battery module 40 does not include a partition wall, and the end of the unit battery case 20 is stacked in contact with the end of the neighboring unit battery 10.

In order to maintain the shape of the recess 22, a rod member 42 having a predetermined cross-sectional shape is inserted into the flow passage 41 of the refrigerant.

The cross-sectional shape of the rod member 42 is not limited, and may have a cross-sectional shape, such as a circle, a square, or a hexagon, as shown in FIGS. 5A to 5C.

In addition, the rod member 42 is inserted into the flow passage of the refrigerant having the same length as the height of the unit cell 10.

In addition, an insulating member 43 may be inserted into a portion where each of the unit cells 10 is in contact so as to maintain insulation between the unit cells 10.

Hereinafter, the operation of the present invention will be described.

At least one of the front side or the rear side of the case 20 of the unit cell has a recessed portion 42 recessed in a gentle arc shape. When the case 20 is stacked in a row, neighboring unit cells ( The end of 10) abuts to form a flow passage 41 of the refrigerant, and no separate partition wall is necessary.

Therefore, the partition wall may be removed to reduce the volume of the battery module 40, and the case 20 of the unit cell may directly contact the refrigerant without interposing the partition wall, thereby reducing the heat transfer path, thereby allowing efficient cooling.

In addition, since the surface of the case 20 which is in contact with the refrigerant is formed of a curved surface rather than a plane, the contact area is widened, thereby increasing the heat transfer area, thereby improving cooling efficiency, and in particular, a structure in which the refrigerant flow passage in the central portion having a large amount of heat is wide The unit cell can be cooled efficiently.

In addition, when the gas is generated due to an unexpected abnormal reaction of the battery, a predetermined volume of surplus space is formed in the case 20 to the left and the right of the case 20 in addition to the portion in which the electrode assembly 14 is embedded. It is possible to prevent the swelling phenomenon by performing a function to receive the gas.

In addition, a vent 34 may be installed in the cap assembly 30 that is coupled to the case, so that when a large amount of gas is generated and the pressure inside the battery case 20 increases, the vent 34 may be opened to release the gas. The shape of the case 20 can be maintained.

In addition, in the battery module 40 according to the present invention, when the rod member 42 is inserted into the refrigerant flow passage 41 to increase the pressure inside the battery, the pressure applied to the recess 22 may be applied to the rod member ( By supporting 42, the curvature of the recess 22 can be maintained to prevent the cooling efficiency from being lowered.

The secondary battery of the present invention is a device that operates by using a motor such as a hybrid electric vehicle (HEV), an electric vehicle (EV), a wireless cleaner, an electric bicycle, an electric scooter, and the like, and is used as an energy source for driving a motor of the device. It may be used and the use is not necessarily limited thereto.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to the range of.

As described above, according to the embodiment of the present invention, the recess portion is formed in the case of the unit cell so that the refrigerant flow passage is formed by the shape of the battery case, thereby increasing the heat transfer area and removing the partition wall. Can reduce the heat transfer path and reduce the heat transfer path, thereby improving the cooling efficiency.

In addition, a surplus space is formed inside the battery case, so that gas can be accommodated to prevent the opening of the vent or delay the breakage, thereby extending the life of the secondary battery.

Claims (26)

Unit cells including at least one of the outer surfaces of the case forming the outer shape to be recessed inward to form a recess; And A housing in which the unit cells are stacked and in which a cooling medium is distributed; Secondary battery module comprising a. The secondary battery module of claim 1, wherein the case has a recess formed only on one surface of the front surface or the rear surface of the case in contact with a neighboring unit battery. The rechargeable battery module of claim 1, wherein the case has recesses formed in both front and rear surfaces thereof in contact with neighboring unit cells. The secondary battery module according to any one of claims 1 to 3, wherein the case is provided with a support part in contact with neighboring unit cells at both ends, and the recess is formed between the support parts. The secondary battery module of claim 4, wherein the case has the recessed portion formed on one surface thereof. The secondary battery module according to any one of claims 1 to 3, wherein the recess is embedded in an arc shape. The secondary battery module according to any one of claims 1 to 3, wherein a rod member is inserted between the unit cells. The rechargeable battery module of claim 7, wherein the rod member has a circular cross-sectional shape. The rechargeable battery module of claim 7, wherein the rod member has a rectangular cross-sectional shape. The rechargeable battery module of claim 7, wherein the rod member has a hexagonal cross-sectional shape. The rechargeable battery module of claim 1, wherein an insulating member is inserted into a portion of the unit cells arranged in a row and in contact with each other. The secondary battery module of claim 1, wherein the unit cell comprises a vent. The secondary battery module of claim 1, wherein the secondary battery is rectangular. An electrode assembly including a separator and a positive electrode plate and a negative electrode plate disposed on both sides of the separator; A case in which the electrode assembly is embedded and at least one of the outer surfaces is recessed to form a recess; And A cap assembly coupled to the case to seal the cap and having a terminal electrically connected to a current collector of the positive electrode plate and the negative electrode plate; Including, The case has a secondary battery is formed in the support portion in contact with the neighboring unit cells at both ends and the recess is formed between the support portion. The rechargeable battery of claim 14, wherein the case has a recess formed only on one surface of the front surface or the rear surface of the case in contact with a neighboring unit battery. The rechargeable battery of claim 14, wherein the case has recesses formed in both front and rear surfaces thereof in contact with neighboring unit cells. delete The secondary battery according to any one of claims 14 to 16, wherein the case has the recessed portion formed on one surface thereof. The secondary battery according to any one of claims 14 to 16, wherein the recess is embedded in an arc shape. The secondary battery of claim 14, wherein the unit cell comprises a vent. One side is opened and the electrode assembly is built in, at least one of the outer surface is recessed inward to form a recess, A secondary battery case having a support portion in contact with neighboring unit cells at both ends, the recess is formed between the support portion. The secondary battery case of claim 21, wherein the recess is formed on only one surface of the front surface or the rear surface of the case in contact with a neighboring unit battery. 22. The rechargeable battery case of claim 21, wherein the case has the recessed portions formed in both front and rear surfaces thereof in contact with neighboring unit cells. delete 24. The secondary battery case of any one of claims 21 to 23, wherein the case has the concave portion formed on an entire surface thereof. The secondary battery case according to any one of claims 21 to 23, wherein the recess is recessed in an arc shape.

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