KR101533574B1 - Method for Manufacturing of Battery Cell Having Bent Sealing Surplus Portion - Google Patents

Abstract

The present invention provides an electrode assembly including a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, the electrode assembly being mounted on a storage portion of the battery case, the battery case including a sealing surplus sealed by heat fusion, A method of manufacturing a battery cell having a structure in which a surplus portion is bent and fixed to a side surface of an electrode assembly receiving portion, the method comprising: (a) fixing the battery cell to a jig, A step of vertically bending the sealing surplus portion by the preheated first block and bringing the sealing surplus portion into close contact with the side surface of the electrode assembly receiving portion; (b) pressing and fixing a sealing surplus portion closely attached to the side surface of the electrode assembly receiving portion by the preheated second block; And (c) pressing and fixing a sealing surplus portion closely attached to the side surface of the electrode assembly receiving portion by the cooled third block.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method of manufacturing a battery cell,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method of manufacturing a battery cell in which a sealing surplus portion is folded, and more particularly, to a method of manufacturing a battery cell in which a battery cell is fixed to a jig, A step of vertically bending the sealing surplus portion to bring the sealing surplus portion into close contact with the side surface of the electrode assembly receiving portion, a step of pressing and fixing the sealing surplus portion closely attached to the side surface of the electrode assembly receiving portion by the preheated second block, And pressurizing and securing the sealing surplus portion, which is in close contact with the side surface of the lead portion, with the cooled third block.

As technology development and demand for mobile devices are increasing, the demand for batteries as energy sources is rapidly increasing, and accordingly, a lot of researches on batteries capable of meeting various demands have been conducted.

Typically, in terms of the shape of a battery, there is a high demand for a prismatic secondary battery and a pouch-type secondary battery which can be applied to products such as mobile phones with a small thickness, and has advantages such as high energy density, discharge voltage, There is a high demand for lithium secondary batteries such as lithium ion batteries and lithium ion polymer batteries.

Also, the secondary battery is classified according to the structure of the electrode assembly having the positive electrode, the negative electrode, and the separator interposed between the positive electrode and the negative electrode. Typically, the long battery- A stacked (stacked) electrode assembly in which a plurality of positive electrodes and negative electrodes cut in a predetermined size unit are sequentially stacked with a separator interposed therebetween, the jelly-roll (wound type) electrode assembly having a structure in which a separator is interposed; A stack / folding type electrode assembly having a structure in which a bi-cell or a full cell is stacked with a predetermined unit of positive and negative electrodes stacked with a separator interposed therebetween.

The secondary battery includes a cylindrical battery and a prismatic battery in which the electrode assembly is housed in a cylindrical or rectangular metal can according to the shape of the battery case, and a pouch type battery in which the electrode assembly is housed in a pouch-shaped case of an aluminum laminate sheet .

In particular, in recent years, a pouch-shaped battery having a structure in which a stacked or stacked / folded electrode assembly is embedded in a pouch-shaped battery case of an aluminum laminate sheet has attracted much attention due to low manufacturing cost, small weight, And its usage is gradually increasing.

FIG. 1 schematically shows a general structure of a typical conventional pouch-type secondary battery as an exploded perspective view.

1, the pouch type secondary battery 10 includes an electrode assembly 30, electrode taps 31 and 32 extending from the electrode assembly 30, electrodes 32 and 33 welded to the electrode taps 31 and 32, Leads 40 and 41, and a battery case 20 accommodating 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 31 and 32 extend from each electrode plate of the electrode assembly 30 and the electrode leads 40 and 42 are connected to a plurality of electrode tabs 31 and 32 extending from each electrode plate, Respectively, and a part of the battery case 20 is exposed to the outside. An insulating film 50 is attached to portions of the upper and lower surfaces of the electrode leads 40 and 41 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 includes a case body 22 including a concave shaped storage portion 23 on which the electrode assembly 30 can be seated and a lid 21 integrally connected to the body 22 And the side portions 24 and the upper portion 25, which are the contact portions, are joined to each other in a state where the electrode assembly 30 is accommodated in the accommodating portion 23, thereby completing the battery. The battery case 20 is made of an aluminum laminate structure of a resin layer / metal foil layer / resin layer so that heat and pressure are applied to both side portions 24 of the main body 22 and the upper end portion 25, The resin layers are bonded together by fusion bonding. The two side portions 24 are in direct contact with the same resin layers of the upper and lower battery cases 20, so that they can be uniformly sealed by melting. On the other hand, since the electrode leads 40 and 41 protrude from the upper end portion 25, the thickness of the electrode leads 40 and 41 and the electrode lead 40, and 41 with the insulating film 50 interposed therebetween.

In such a pouch-shaped battery cell, the sealing surplus portions of the outer circumferential surface formed for sealing the electrode assembly and the electrolyte from the outside cause an increase in size of the battery, and therefore, it is necessary to adhere to the side surface of the electrode assembly receiving portion.

This adhesion process is generally performed by manual operation, so that the productivity is very low. In addition, when the process is performed through some automation process, the single-sheet pouch-type case in which a plurality of layers are stacked tends to be restored to the state before bending And the structural stability of the bending state is not excellent.

Therefore, there is a high need for a technology that can fundamentally 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.

The inventors of the present application conducted intensive research and various experiments to confirm that the manufacturing process of the battery cell in which the sealing surplus portion is bent is brought into close contact with the side surface of the electrode assembly receiving portion with the adhesive member using a predetermined block, The bending and pressing of the sealing surplus portion and the fixing of the sealing surplus portion in the cooled block can be performed by an automated process and an excellent adhesion can be provided even after bending. And that the structural stability was greatly improved.

Accordingly, it is an object of the present invention to provide a method of manufacturing a battery cell having excellent structural stability in a bent state while exhibiting production efficiency by an automated process.

According to an aspect of the present invention, there is provided a method of manufacturing a battery cell,

An electrode assembly including a positive electrode, a negative electrode, and a separator interposed between an anode and a cathode is mounted on a storage portion of a battery case, and the battery case includes a sealing surplus portion sealed by heat fusion, A method of manufacturing a battery cell having a structure in which the battery cell is bent and fixed to a side surface of an assembly housing part,

(a) fixing the battery cell to a jig, applying a viscous member onto the sealant, and vertically bending the seal surplus portion with the preheated first block to closely contact the side surface of the electrode assembly receiving portion Process;

(b) pressing and fixing a sealing surplus portion closely attached to the side surface of the electrode assembly receiving portion by the preheated second block; And

(c) pressing and fixing the sealing surplus portion closely attached to the side surface of the electrode assembly receiving portion by the cooled third block;

As shown in Fig.

As described above, the method of manufacturing a battery cell according to the present invention comprises a step of bending and compressing a sealing surplus portion in the state where the viscous member is interposed by the preheated blocks and then fixing the same in a cooled block, The process of bending and fixing the part can be carried out by an automated process, thereby improving the production efficiency and, at the same time, greatly improving the structural stability in the sealed state.

In one specific example, the method of manufacturing a battery cell according to the present invention may have a structure in which sealing surplus portions at portions where the positive and negative terminals are not formed are vertically bent and brought into close contact with the side surface of the electrode assembly receiving portion.

In detail, the jig includes an upper jig and a lower jig for fixing the upper and lower surfaces of the battery cell, respectively. In the upper jig and / or the lower jig, , And one or more inlets of the air suction type.

In one specific example, the first block includes an upper block and a lower block, wherein the upper block and the lower block are located at upper and lower portions to face each other with the sealing surplus portion interposed therebetween, and the lower block The upper surface of the surface and the lower block may have a slope of 10 to 80 degrees, preferably 20 to 70 degrees, based on the horizontal surface of the battery cell.

In addition, the first block may be preheated to 100 to 150 degrees, for example, in order to facilitate the process of imparting sealability and tackiness of the adhesive member to the electrode assembly receiving portion. If the temperature is too low, the process of imparting tackiness may not be easy. On the other hand, if the temperature is too high, there is a possibility that some components may leak due to the viscosity decrease of the viscous member. More preferably 100 to 140 degrees, and particularly preferably 110 to 130 degrees.

In one specific example, the process (a)

(i) fixing the battery cell by the jig;

(ii) applying a viscous member on the sealant by a first block; And

(iii) bending the sealing surplus portion by the first block and bringing the sealing surplus portion into close contact with the side surface of the electrode assembly receiving portion;

. ≪ / RTI >

In this case, the step (ii) may be carried out under the condition that the first block is pressed for 1 to 5 seconds in the vertical direction at a pressure of 0.1 to 0.7 MPa with the sealing surplus portion therebetween, Under a pressure of 0.5 MPa for 1 to 2 seconds.

The sticky member may be, for example, a sticky material or a sticky double-sided tape, and is applied between the side surface of the electrode assembly receiving portion and the sealant to adhere the seal surplus portion to the side surface of the electrode assembly receiving portion.

In the step (b), the second block may be preheated at 80 to 150 degrees, preferably at 80 to 130 degrees, more preferably at 90 to 110 degrees.

In the step (b), the sealing surplus portion brought into close contact with the side surface at a pressure of 0.1 to 0.5 MPa is applied to the first block in a range of 1 to 10 seconds And may preferably be pressurized for 3 to 9 seconds at a pressure of 0.1 to 0.2 MPa.

In the step (c), the third block may be cooled by 10 to 25 degrees, preferably by 10 to 20 degrees, more preferably by 15 to 20 degrees.

The step (c) may be carried out under the condition that the third block presses the sealing surplus which is in close contact with the side surface at a pressure of 0.1 to 0.7 MPa through the battery cell for 1 to 10 seconds, May be carried out under conditions of a pressure of 0.1 to 0.5 MPa for 3 to 9 seconds.

In some cases, the step (c) further includes the step of injecting the compressed air to the sealing residue in a state in which the sealing surplus portion in contact with the side surface of the electrode assembly receiving portion is compressed by the third block .

In this case, the injection of the compressed air may be performed at a pressure of 0.10 to 0.50 MPa for 1 to 10 seconds, preferably at a pressure of 0.10 to 0.20 MPa for 3 to 9 seconds.

Accordingly, the first block and the second block of the process (a) and the process (b) are preheated to a predetermined temperature to pressurize the sealing surplus portion to easily adhere to the side surface of the electrode assembly receiving portion, The sealing surplus portion can be more firmly fixed to the side surface of the electrode assembly receiving portion by pressing the sealing surplus portion. As a result, the structural stability of the bent state can be improved.

The processes (a), (b) and (c) may be performed for 5 to 10 seconds, respectively. However, when the conditions such as the temperature of the block, Of course, can be changed.

The battery case according to the present invention is not particularly limited as long as it is a material capable of sealing by heat fusion, and may be, for example, a laminate sheet having a structure including a metal layer and a resin layer. As a specific example, such a laminate sheet may be an aluminum laminate sheet.

The electrode assembly is not particularly limited as long as it is composed of an anode, a cathode, and a separator interposed therebetween, and may be, for example, a winding type, a stack type, or a stack / winding type structure.

In one specific example, the electrode assembly includes a plurality of positive electrodes, a negative electrode, and a separator sequentially stacked on the sealing surplus portion, and the electrode assembly is folded vertically and brought into close contact with the side surface of the electrode assembly receiving portion. Lt; / RTI >

In this case, the sealing surplus portion may be chamfered to a predetermined size at an edge portion where the sealing surplus portions intersect so that the sealing surplus portion can be easily bent to be brought into close contact with the side surface of the receiving portion.

The present invention also provides a battery cell manufactured by the above method, wherein the battery cell may be a lithium secondary battery.

The secondary battery may preferably be a lithium secondary battery having high energy density, discharge voltage, and output stability. Other components of such a lithium secondary battery will be described in detail below.

Generally, a lithium secondary battery is composed of a positive electrode, a negative electrode, a separator, a non-aqueous electrolyte containing a lithium salt, and the like.

The positive electrode is prepared, for example, by applying a mixture of a positive electrode active material, a conductive material and a binder on a positive electrode current collector, followed by drying, and if necessary, a filler is further added. The negative electrode is also manufactured by applying and drying the negative electrode material on the negative electrode collector, and if necessary, may further include the above-described components.

The separation membrane is interposed between the cathode and the anode, and an insulating thin film having high ion permeability and mechanical strength is used.

The lithium salt-containing nonaqueous electrolyte solution is composed of a nonaqueous electrolyte and a lithium salt. As the nonaqueous electrolyte solution, a liquid nonaqueous electrolyte, a solid electrolyte, and an inorganic solid electrolyte are used.

The collector, the electrode active material, the conductive material, the binder, the filler, the separator, the electrolyte, and the lithium salt are well known in the art, and a detailed description thereof will be omitted herein.

Such a lithium secondary battery can be produced by a conventional method known in the art. That is, a porous separator may be inserted between the anode and the cathode, and an electrolyte may be injected into the separator.

The anode can be produced, for example, by applying a slurry containing the above-described lithium transition metal oxide active material, a conductive material and a binder on a current collector, followed by drying. Likewise, the negative electrode can be produced, for example, by applying a slurry containing the above-described carbon active material, a conductive material and a binder onto a thin current collector and then drying it.

The present invention also provides a device comprising one or more of the battery cells, wherein the device is a mobile phone, a tablet computer, a notebook computer, a power tool, an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, Device or the like.

Such devices or devices are well known in the art, so a detailed description thereof will be omitted herein.

As described above, the method for manufacturing a battery cell according to the present invention comprises the step of bending and pressing the sealing surplus portion with the viscous member interposed by the preheated blocks, and then fixing the sealing surplus portion with the cooled block, So that the production efficiency is improved, and in addition, the structural stability of the state in which the sealing surplus portion is bent can be greatly improved.

1 is an exploded perspective view of a general structure of a conventional pouch type secondary battery;
2 to 4 are schematic schematic views of a method of manufacturing a battery cell according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to the drawings according to the embodiments of the present invention, but the scope of the present invention is not limited thereto.

2 to 4 are schematic diagrams of a method of manufacturing a battery cell according to an embodiment of the present invention.

2, in order to fix the battery cell 100, the upper jig 110 and the lower jig 120 are placed on the upper and lower surfaces of the battery cell 100, do.

The first block is provided with the adhesive members 170 and 180 and the first block is provided with the adhesive members 170 and 180 to which the sealing members 130 and 140 of the battery cell 100, The sealant 130, 140 is squeezed and then removed.

In this case, the first block includes a top block 150 and a bottom block 160, and the top block 150 and the bottom block 160 have a structure in which the first and second blocks 150, The lower end face of the upper block 150 and the upper end face of the lower block 160 facing each other form an inclined face of 10 to 80 degrees with respect to the horizontal plane of the battery cell 100. [

The first block is preheated at a temperature of 100 to 150 degrees Celsius and is then removed by pressing the sealant 130 or 140 for 1 to 2 seconds in a vertical direction at a pressure of 0.1 to 0.5 MPa and at the same time, The protective tapes 171 and 181 attached to the orientation surfaces of the surfaces to be applied to the sealing extensions 130 and 140 are removed.

By this pressing, the sealing abutments 130, 140 to which the viscous members 170, 180 are applied are completely vertically bent by the upward and downward movement of the lower block 160, and are brought into close contact with the side surface of the electrode assembly receiving portion.

3, sealing residues 130 and 140 adhered to the side surfaces of the electrode assembly receiving part by the first blocks 150 and 160 are fixed to the jig 220 on the lower surface of the battery cell 100 Is pressed and fixed by the second block (250).

The second block 250 is preheated at a temperature of 90 to 110 degrees and pressurized at a pressure of 0.1 to 0.2 MPa for 3 to 9 seconds through the battery cell 100 on the side surface of the battery cell 100 and then removed.

4, the sealing block 130 and 140, which are pressed and fixed to the side surface of the electrode assembly receiving portion by the second block 250, are fixed to the jig 320 on the lower surface of the battery cell 100 And is pressed and fixed by the third block 350.

The third block 350 is cooled to 15 to 20 degrees and is then pressed for 3 to 9 seconds at a pressure of 0.1 to 0.5 MPa through the battery cell 100 on the side surface of the battery cell 100 and then removed.

The sealant 130, 140 may further include injecting the compressed air 330 for 3 to 9 seconds at a pressure of 0.10 to 0.20 MPa while the third block 350 is being pressurized.

The adhesive members 170 and 180 applied to the cooling and fixing sealants 130 and 140 after being compressed to a high temperature according to the above Figures 2 to 4 are heated by the temperature changes by the blocks 150, And the battery cell 100 is firmly fixed to the electrode assembly receiving portion by exerting a high adhesive force due to the pressurization, thereby providing a structurally more stable battery cell 100. [

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 (21)

An electrode assembly including a positive electrode, a negative electrode, and a separator interposed between an anode and a cathode is mounted on a storage portion of a battery case, and the battery case includes a sealing surplus portion sealed by heat fusion, A method of manufacturing a battery cell having a structure in which the battery cell is bent and fixed to a side surface of an assembly housing part,
(a) fixing the battery cell to a jig, applying a viscous member on the sealant, and vertically bending the seal surplus portion with the preheated first block to closely contact the side surface of the electrode assembly receiving portion Process;
(b) pressing and fixing a sealing surplus portion closely attached to the side surface of the electrode assembly receiving portion by the preheated second block; And
(c) pressing and fixing the sealing surplus portion closely attached to the side surface of the electrode assembly receiving portion by the cooled third block;
/ RTI >
The process (a)
(i) fixing the battery cell by the jig;
(ii) applying a viscous member on the sealant by a first block; And
(iii) bending the sealing surplus portion by the first block and bringing the sealing surplus portion into close contact with the side surface of the electrode assembly receiving portion;
And forming a battery cell. The method for manufacturing a battery cell according to claim 1, wherein the sealing surplus portions of the portion where the positive electrode terminal and the negative electrode terminal are not formed are vertically bent and brought into close contact with the side surface of the electrode assembly receiving portion. 2. The battery pack of claim 1, wherein the jig includes an upper jig and a lower jig for respectively fixing upper and lower surfaces of the battery cell, and the upper jig and / Wherein the at least one inlet of the battery cell comprises at least one inlet. The method of claim 1, wherein the first block includes an upper block and a lower block,
The upper block and the lower block are located at upper and lower sides so as to face each other with the sealing surplus portion interposed therebetween, and the lower end face of the upper block and the upper end face of the lower block facing each other are inclined with respect to the horizontal plane of the battery cell, Is formed on the surface of the battery cell. The method of claim 1, wherein the first block is preheated at 100 to 150 degrees. delete The method for manufacturing a battery cell according to claim 1, wherein the step (ii) comprises pressing the first block at a pressure of 0.1 to 0.5 MPa for 1 to 2 seconds in a vertical direction with the sealing surplus portion interposed therebetween. The method of claim 1, wherein the viscous member is a sticky material or a sticky double-sided tape, and is applied between the side surface of the electrode assembly receiving part and the sealant. The method of claim 1, wherein the second block is preheated at 90 to 110 degrees. The method according to claim 9, wherein the step (b) comprises pressing the sealing surplus portion, which is in close contact with the side surface, at a pressure of 0.1 to 0.2 MPa with the second block interposed therebetween for 3 to 9 seconds. ≪ / RTI > The method of claim 1, wherein the third block is cooled to 15 to 20 degrees. The method according to claim 1, wherein in the step (c), the third block presses the sealing surplus which is in close contact with the side surface at a pressure of 0.1 to 0.5 MPa through the battery cell for 3 to 9 seconds A method of manufacturing a battery cell. The method according to claim 1, wherein the step (c) further includes the step of injecting compressed air to the sealant in a state in which the seal surplus portion in close contact with the side surface of the electrode assembly receiving portion is compressed by the third block Wherein the battery cell is manufactured by a method comprising the steps of: 14. The method of claim 13, wherein the injection of the compressed air is performed at a pressure of 0.10 to 0.20 MPa for 3 to 9 seconds. The method of claim 1, wherein the steps (a), (b), and (c) are performed for 5 to 10 seconds. The method of claim 1, wherein the battery case comprises a laminate sheet including a resin layer and a metal layer. The method according to claim 1, wherein the electrode assembly has a plate-like hexahedral structure, and a corner of a predetermined size is chamfered to facilitate bending of edges of the sealing surplus portion. A battery cell characterized by being manufactured by the method according to any one of claims 1 to 5 and 7 to 17. The battery cell according to claim 18, wherein the battery cell is a lithium secondary battery. A device comprising at least one battery cell according to claim 19. 21. The device of claim 20, wherein the device is a mobile phone, a tablet computer, a notebook computer, a power tool, an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or a power storage device.

Images