KR20180092174A - Apparatus and method for forming pouch of secondary battery secured residual thickness - Google Patents

Abstract

The present invention relates to a forming apparatus, comprising a forming die at the lower portion thereof, a pressing punch at the upper portion thereof, and a stripper (also arranged at an escape portion) or a roller guiding a pouch forming metal from the forming die and an introduction portion of the pressing punch, wherein the forming die, the pressing punch, and the stripper or the roller are installed with a heater therein such that a pouch survival rate during forming a pouch can be secured, thereby capable of securing a pouch survival rate of a secondary battery.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a molding apparatus and a method for securing a residual ratio of a pouch of a secondary battery,

The present invention relates to an apparatus and a method for molding a pouch of a secondary battery, and more particularly, to an apparatus and a method for molding a pouch of a secondary battery, To a molding apparatus and method for securing the remaining ratio.

Generally, a battery is obtained by using a chemical or physical reaction to obtain electric energy. Such a chemical battery is divided into a primary battery and a secondary battery. That is, a secondary battery is called a primary battery, such as a manganese battery, an alkaline battery, and a mercury battery, which is called a primary battery, and a secondary battery that can be recharged after using electricity such as a rechargeable battery or a lead acid battery.

This secondary battery is formed of a battery cell type in which a plurality of cells, that is, unit cells, are connected to each other in consideration of charge / discharge efficiency and current capacity. At present, the secondary battery has high energy density, light weight, high voltage, High-speed charging, and excellent life span.

Such a secondary battery includes an electrode assembly in which an anode, a cathode, and a separator interposed therebetween are repeatedly stacked, a pouch in which the electrode assembly is accommodated, and an electrolyte solution of an electrode assembly injected into the pouch.

Meanwhile, the pouch is formed as an electrode assembly receiving portion for receiving the electrode assembly, and the electrode assembly receiving portion is formed through the pouch forming device. Typically, the pouch is formed primarily of aluminum.

The pouch forming apparatus according to the prior art presses the surface of the pouch through a press to form the electrode assembly receiving portion.

Fig. 1 is a schematic view showing a pouch forming apparatus for a secondary battery according to the prior art. The molding apparatus 10 is a typical general press type, and includes a molding die 11 on the lower side, a press punch 12 on the upper side, The pouch-forming metal 13 is disposed between the pouch-forming metal 13 and the pouch-forming metal 13, and in this case, the remaining ratio (rate of change of the thickness layer) is low at a large molding area, adversely affecting the stability of the pouch.

That is, in the pouch forming apparatus according to the related art, when the electrode assembly receiving portion is formed, the corners of the electrode assembly receiving portion are bent while being excessively stretched. At this time, the residual ratio of the pouch forming metal on the curved surface decreases, . Decrease of the residual ratio may lead to problems such as cracks, decrease in insulation, leakage of electrolyte, and the like.

The present invention has been conceived in order to solve the above-mentioned problems, and an object of the present invention is to provide a pouch forming method and a pouch forming method which can heat a corner portion of a pouch forming metal to increase the remaining ratio of a molding metal to prevent cracking, have.

According to one aspect of the present invention, there is provided a press forming apparatus comprising: a molding die on a lower side and a press punch on an upper side; and a stripper (also disposed on the escape side) or a roller for guiding the pouch forming metal from the molding die and the inlet side of the press punch, And a heater is installed inside each of the die, the press punch, the stripper, and the roller so as to secure the pouch remaining ratio when the pouch of the secondary battery is molded, thereby providing a molding apparatus for securing the remaining pouch ratio of the secondary battery.

According to a preferred embodiment of the present invention, the molding apparatus is intended to form a metal capable of hot forming.

According to a preferred embodiment of the present invention, the heater mounted on the pressurizing punch and the molding die is provided at a corner where the pressurizing punch and the molding die mesh with each other to raise only the temperature of the corner portion of the formed molding metal, The corner portion where the molding die is engaged may be rounded.

According to a preferred embodiment of the present invention, the heater provided in the stripper causes heat to be applied to the entire molded metal introduced into the molding die.

According to a preferred embodiment of the present invention, the heater provided on the roller applies heat only to a portion of the molding metal that is introduced into the molding die as a corner of the secondary battery pouch according to regular upward and downward movement of the roller.

According to a preferred embodiment of the present invention, the heaters are heated in a manner selected from gas heating, electrothermal heating, high frequency induction heating.

According to another aspect of the present invention, there is provided a secondary battery comprising: a pressing punch on an upper side other than a forming die on a lower side; a stapler or a roller on a side introduction portion of the pressing punch and the molding die; Preparing a metal for a pouch capable of hot forming using a molding apparatus; Heating the metal while moving along the roller or the stripper; And pressing the heated metal while heating only the edge portion using a pressurizing punch and a molding die.

According to another aspect of the present invention, there is provided a secondary battery pouch manufactured by the pouch forming method of the secondary battery according to the present invention.

According to another aspect of the present invention, there is provided a secondary battery including the secondary battery pouch manufactured by the pouch forming method of the secondary battery according to the present invention.

The apparatus and method for pouch-forming a secondary battery according to the present invention can increase the remaining ratio of the molded metal when the pouch is molded from the pouch-forming metal, thereby preventing the pouch from cracking, reducing insulation, .

1 is a schematic view showing a pouch forming apparatus for a secondary battery according to the prior art,
FIG. 2 is a schematic view showing a pouch molding apparatus for a secondary battery in which a heater is mounted on each of a molding die, a pressing punch,
3 is a schematic view showing a pouch molding apparatus for a secondary battery in which a heater is mounted on each of a forming die and a pressurizing punch of another configuration according to the present invention,

Hereinafter, preferred embodiments of the present invention will be described in detail. The present invention is not limited to the scope of the present invention, but is merely an example, and various modifications can be made without departing from the technical gist of the present invention.

The pouch forming apparatuses 100 and 200 of the secondary battery according to the present invention are devices for molding the pouch of the secondary battery by pressing the surface of the pouch forming metal 130 as shown in Figs. 2 and 3, The lower die molding dies 110 and 210 and the upper side press punches 120 and 220 as the structure and the stripper 140 or the roller 240 at the side entry portions of the molding die and the press punch.

2, a pouch forming apparatus 100 for a secondary battery according to an embodiment of the present invention includes a lower molding die 110, an upper side pressing punch 120 And the molding die 110 and the press punch 120 are provided with pouch forming metal 130 between the molding die 110 and the press punch 120. Both sides of the press die 120 and the press punch 120 The stripper 140 is positioned. A heater 150 is disposed inside each of the molding die 110, the pressing punch 120, and the stripper 140. The stripper 140 may be installed only at the introduction portion.

The molding die 110 on the lower side is formed with a concave forming groove 111 in which the pouch forming metal 130 is disposed to form an electrode assembly receiving portion.

The upper side pressing punch 110 is for pressing the pouch forming metal 130 to form an electrode assembly accommodating portion. The upper side pressing punch 110 is formed on the upper portion of the pouch forming metal 130 disposed on the lower side molding die 120, And is capable of being lowered toward the side molding die 110 and functions to mold the electrode assembly receiving portion while being coupled to the molding groove 111 in a state in which the surface of the pouch metal 130 is pressed.

The lower molding die 110 and the upper side pressing punch 120 are moved downward from the upper portion toward the lower molding die 110 and come into close contact with each other so that the upper pressing punch 120 The electrode assembly receiving portion is formed in the pouch metal 111 while being coupled to the forming groove 111 of the lower molding die 110 in a state of pressing the surface of the pouch metal 111.

On the other hand, when the electrode assembly accommodating portion is formed, the bottom corner of the electrode assembly accommodating portion is excessively pulled, and the residual ratio of the pouch metal decreases, resulting in the occurrence of a crack.

In order to solve such a problem, the bottom corner of the electrode assembly accommodating portion is heated to increase the residual ratio of the pouch metal, and as the flexibility increases, cracks are prevented from occurring at the lower corner of the electrode assembly accommodating portion and the electrolyte leakage and electrolyte leakage A heater that can be used may be included.

To this end, a plurality of heaters 150 (three each in this embodiment) may be installed in the molding die 110 and the press punch 120 at the corner where the punch and the die engage, Only the temperature of the corner portion of the wafer is increased. When the punch and the die are used for press working, the residual rate is reduced at the corners, and intensive heating only increases the energy efficiency in producing pouches. In addition, there is an advantage that the residual ratio of only the corner portion can be improved and the metal remaining ratio of the entire pouch can be leveled. In this case, the corner portions where the pressing punch and the molding die are engaged with each other can be rounded as described above, and the rounded structure is more advantageous in preventing cracks than the rectangular corner structure. In the case of the rectangular corner structure, the metal residual ratio at the angular portion is drastically reduced, but when the rounding treatment is performed, the decrease in the metal residual ratio becomes more gentle, and therefore, it is more advantageous in preventing cracks.

In addition, the heater 150 may be installed in the stripper 140 to apply heat to the entire formed metal 130 to be supplied to the molding die 110. The heater 150 installed in the stripper 140 may be installed either in the inlet or outlet of the metal or only in the inlet. The heater 150 installed in the stripper 140 uniformly applies heat to the entire molding metal 130 introduced into the molding die 110. Therefore, the moldability of the entire formed metal 130 is improved, and the residual ratio of the edge portion of the pouch in which the residual metal ratio is a problem is also increased. However, when a heater is provided only in the stripper 140, the residual metal ratio may vary depending on the pouch portion. Therefore, it is preferable that a heater is also provided at a position where the punch and the die are engaged with each other.

Further, the molding apparatus 100 is characterized in that a metal capable of hot forming is formed. For example, aluminum is a metal which can be subjected to hot-plastic working, and when it is heated through a stripper, a roller, a punch and a die, the aluminum is changed to a state of good moldability, and in this state,

3, a pair of rollers 240 may be disposed on the inlet side instead of the structure of the stripper 140 in the embodiment to form the pouch forming metal 230 ). ≪ / RTI > At this time, the heater 250 is installed in each of the pair of rollers 240.

The roller 240 serves to improve the formability by previously rolling a metal capable of hot-firing together with the heater 250. The pair of rollers 240 have a structure in which only a part of the roller surface is heated by the heater and the heat source is transmitted to the forming metal 230, rather than having a heater on the entire roller surface. For example, when the heater 250 is located at a midpoint between a roller center axis and a circular point, the roller 250 is heated only at the roller surface of the portion where the heater is located, And the forming metal 230 receives heat only at a portion where the forming metal 230 meets the roller surface, and becomes a state capable of hot forming.

In this case, it is possible to obtain the heated molded metal at a predetermined interval by adjusting the timing of the pouch forming metal 230 and the roller surface for conveying the heat, and if the heated portion is aligned with the edge portion of the pouch, It is possible to increase the remaining ratio of the molding metal at the corner portion during molding.

It is difficult to simultaneously install the heater in the stripper 140 according to an embodiment of the present invention when the heater is installed in the pair of rollers 240 because of a space limitation. However, it is possible to provide at least one heater 250 to the molding die 210 and the pressurizing punch 220.

In the present invention, the heating method of the heaters 150 and 250 is heated in one method selected from a gas heating type, an electric heating type, and a high frequency induction heating type. In the gas heating type, a gas burner is contained in a heater, and gas is injected through the burner to burn the gas. The heating cost is low and the component construction can be simplified. However, since the gas pipe must be connected, there is a disadvantage that installation is restricted in a part where movement is much.

The electric heating system draws the heating wire into the heater and heats the heating wire by heating the heating wire. Although the movement of the heater can be made more freely than the gas pipe, there is a disadvantage that the energy consumption is large.

The high frequency induction heating type generates a magnetic field to generate heat in accordance with the high frequency induction heating principle. For example, it may include an induction coil for generating a magnetic field when power is applied, and a metal piece wound around the induction coil and generating heat by inducing a magnetic field generated from the induction coil. The metal piece is preferably made of steel. That is, a magnetic field generated in the induction coil is induced in the metal piece, the metal piece gradually generates heat, and the heat source of the metal piece is discharged to the outside, thereby heating a portion close to the metal piece.

A method of forming a pouch of a secondary battery using the pouch forming apparatus for a secondary battery according to the present invention comprises the steps of: preparing a metal for pouch capable of hot forming; Heating the metal while moving along the roller or the stripper; And pressing the heated metal while heating only the edge portion using a punch and a die.

The metal for the pouch capable of hot forming is preferably a metal capable of hot-setting. The metal that can be hot-baked is advantageous in improving the residual ratio of the corner portion at the time of press forming. Although it is possible to use a method of increasing the strength of the metal by hot forming, if the strength is excessively increased, the possibility of occurrence of crake increases, which is not preferable.

When the shaped metal is heated while moving along the stripper 140 or the roller 240, the heated shaped metal is in a state suitable for plastic working. As described above, when the heater is used for the stripper 140, the entire formed metal is heated. When the heater is used for the roller 240, the heated section is displayed at a constant interval. Therefore, the roller or the stripper can be arranged as required, and the simultaneous disposition of the roller or the stripper is not preferable because the heating characteristics are different and the space is also limited.

When the heated metal is pressed using a punch and a die, a forming groove is formed in which the electrode assembly is received. It is also possible to heat the edge only by placing a heater in the punch and the die.

The secondary battery pouch according to the present invention is manufactured by the above-described pouch forming method. Such a secondary battery pouch has a high residual ratio of edges at the time of molding in the form of a pouch cup, so that the incidence of the creep is low and the electrode assembly can be adequately protected. Therefore, the secondary battery pouch according to the present invention can have high quality.

The secondary battery according to the present invention includes such a secondary battery pouch. That is, the secondary battery according to the present invention can be manufactured by housing the electrode assembly and the electrolyte in the secondary battery pouch manufactured by the above-described secondary battery pouch forming method, and sealing the same with the sealing part.

Hereinafter, the present invention will be described in more detail by way of examples. However, the following examples and comparative examples are provided for illustrating the present invention, and the scope of the present invention is not limited by these examples and experimental examples.

≪ Example 1 >

The heating punch and the molding die are equipped with a heater at the corner where they engage with each other and a stripper with a heater to heat the heater at a temperature of 380 ° C when the molding metal (aluminum) is poured, and 300 ° C And a secondary battery pouch was formed by heating.

≪ Example 2 >

A secondary battery pouch was formed in the same manner as in Example 1, except that the molded metal was heated to 300 캜 at regular intervals while passing through a roller equipped with a heater before charging the molding die.

≪ Comparative Example 1 &

The secondary battery pouch was molded in the same manner as in Example 1 with the configuration of the prior art (no press punch without heater, molding die structure, and no stripper or roller configuration).

The aluminum remaining ratio of the secondary front pouches (corner portions) of Examples 1 and 2 and Comparative Example was measured and shown in Table 1 below.

division Remaining rate (%) Example 1 95 Example 2 96 Comparative Example 1 87

At this time, the residual ratio (%) is the molded metal thickness after molding / the molded metal thickness before molding is 100.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.

10, 100, 200: Pouch forming device
11, 110, 210: Molding die
12, 120, 220: pressure punch
13, 130, 230: forming metal
111: forming groove
140: Stripper
150, 250: heater
240; roller

Claims (12)

And a stripper for guiding the pouch forming metal to the side introduction portion and the escape portion side of the molding die and the pressing punch,
Wherein a heater is installed inside each of the molding die, the press punch, and the stripper to secure the pouch remaining ratio when the pouch of the secondary battery is molded. The molding apparatus for securing the remaining pouch ratio of the secondary battery. And a pair of rollers for guiding the pouch forming metal to the side introduction portion side of the molding die and the press punch,
Wherein a heater is installed inside each of the molding die, the pressurizing punch and the roller so as to secure the pouch remaining ratio in the pouch molding of the secondary battery. 3. The method according to claim 1 or 2,
Wherein the molding apparatus forms a metal capable of hot forming. The molding apparatus for securing a remaining pouch ratio of a secondary battery. 3. The method according to claim 1 or 2,
Wherein the molding die and the heater provided in the pressing punch are provided at corner portions which are engaged with each other so that only the temperature of the corner portion of the molded metal is raised. 3. The method according to claim 1 or 2,
Wherein a corner portion where the molding die and the pressure die are engaged is rounded. 3. The method according to claim 1 or 2,
Wherein the heater is heated in one of a gas heating type, an electric heating type, and a high frequency induction heating type. The method according to claim 1,
Wherein the stripper is installed at an inlet portion of the secondary battery. 8. The method of claim 1 or 7,
Wherein the heater provided in the stripper applies heat to the whole of the molding metal to be introduced into the molding die. 3. The method of claim 2,
Wherein the heater provided on the roller is adapted to apply heat only to a portion of the forming metal that is to be inserted into the die as the roller moves up and down in order to be an edge of the secondary battery pouch. . A molding method for securing a residual ratio of a pouch of a secondary battery using a molding apparatus for securing a remaining pouch ratio of a secondary battery according to claim 1 or 2,
Preparing a metal for pouch capable of hot forming;
Heating the metal while moving along the roller or the stripper;
Pressing the heated metal while heating only the edge portion using a punch and a die;
Wherein the pouch is made of a resin. A secondary battery pouch manufactured by a molding method for securing a remaining pouch ratio of a secondary battery according to claim 10. A secondary battery comprising a secondary battery pouch manufactured by a molding method for securing a remaining pouch ratio of the secondary battery according to claim 10.

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