JP2001357839A - Method of manufacturing for battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing for a battery capable of preventing the soiling of a roll for carrying a separator 4 caused by an adhesive 2 and the breakage of the separator 4 by unreasonable force applied to the separator 4. SOLUTION: The adhesive 2 within recesses 1a installed on the surface of a coating roll 1 is transferred to the surface of the separator 2. The adhesive 2 is supplied to the surface of the separator 4 stretched between two carrying rollers 6 and 6 and transferred to the separator 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a battery in which a separator is bonded to an electrode.

[0002]

2. Description of the Related Art Since a lithium ion secondary battery uses a non-aqueous electrolyte having high reactivity, when the battery is abnormal, it may be decomposed by heat generation to generate gas. Therefore, polymer batteries using a polymer electrolyte as the non-aqueous electrolyte have been conventionally developed. In this polymer battery, by interposing a polymer electrolyte layer between the positive electrode and the negative electrode, excess electrolyte is reduced, gas generation is reduced, and the safety of the lithium ion secondary battery is enhanced. . Further, when the gas generated inside the element stops in the gap, the gas expands the element and deteriorates the thermal conductivity, so that heat may be trapped inside and the center may be heated further. However, in the case of a polymer battery, since the polymer electrolyte layer firmly adheres the overlapped positive electrode and negative electrode, it is possible to prevent the element from swelling due to gas and to easily release internal heat.

[0003] In such a polymer battery, an element is prepared by bonding a separator to both surfaces of a negative electrode with an adhesive in advance and winding the negative electrode while applying an adhesive to both surfaces of the positive electrode. is there. In this polymer battery, after winding the element, the adhesive is dried and then impregnated with a non-aqueous electrolyte to form a polymer electrolyte layer.

[0004] When a separator is bonded to the negative electrode of the polymer battery, an adhesive is first applied to the surface of the separator, and then the negative electrode is overlaid thereon to perform bonding. This is because, if an adhesive is first applied to the surface of the negative electrode, the adhesive may lower the ionic conductivity, thereby lowering the capacity of the battery or lowering the high-rate discharge performance.

A conventional method of applying an adhesive to the surface of the separator will be described with reference to FIG. A large amount of adhesive 2 is stored on a roll surface facing upward from a coating roll 1 rotating on a horizontal rotation axis. Then, the adhesive 2 is limited to a certain thickness by the comma roll 7 and is sequentially supplied onto the roll surface of the coating roll 1 which is directed downward by rotation. Also,
The back surface of the separator 4 is laid over the roll surface of the back roll 5 rotating in the same direction on a parallel rotating shaft located at the same height as the coating roll 1, and the separator 4 is directed upward from below the back roll 5. Conveyed. In addition, the back roll 5 is configured such that the surface of the separator 4 conveyed on the roll surface is lightly pressed against the roll surface of the coating roll 1 to which the adhesive 2 is supplied. For this reason, the surface of the separator 4 conveyed upward rubs against the roll surface of the coating roll 1 facing downward, so that the adhesive 2 supplied on this roll surface is applied to the surface of the separator 4 by a constant amount. It can be transferred in thickness.

[0006]

However, in the above-mentioned conventional method, the adhesive 2 is applied to the entire width of the separator 4 conveyed on the roll surface of the back roll 5 so that the adhesive 2 can be applied. Since the adhesive 2 is supplied over a wider area than the width of the separator 4 on the roll surface, both ends of the roll surface of the back roll 5 are stained by the adhesive 2. Also, the separator 4
Is a porous film made of resin, so that the adhesive 2
When this is applied, the solvent of the adhesive 2 oozes out to the back side and adheres to the back roll 5 and the roll that transports the separator 4, causing a problem that the transport becomes an obstacle.

Further, since the roll surface of the coating roll 1 and the surface of the separator 4 rub against each other while moving in opposite directions, an excessive force is applied to the thin resin separator 4 having a thickness of about several tens of μm, so that the separator 4 is easily broken. There were also problems. If the thickness of the separator 4 is increased so that the separator 4 is not easily broken, the space is unnecessarily occupied in the element, and the energy density of the battery to be manufactured is reduced.

The present invention has been made in order to cope with such a situation, and transfers an adhesive to the surface of a separator in an appropriate pattern, or applies an adhesive to the surface of a separator stretched between transport rolls. It is an object of the present invention to provide a method for manufacturing a battery in which the transfer of the separator does not stain the roll for transporting the separator and the separator during transport is not broken.

[0009]

According to a first aspect of the present invention, there is provided a battery manufacturing method, wherein an adhesive is sequentially supplied into a concave portion provided on a roll surface with rotation of a coating roll, and a concave portion of the coating roll is provided. The surface of the separator is sequentially pressed against the roll surface to which the adhesive has been supplied,
The adhesive in the recess is transferred to the surface of the separator, and the separator is bonded to the electrode by superimposing the surface of the electrode on the surface of the separator to which the adhesive has been transferred.

According to the first aspect of the present invention, since only the adhesive supplied to the concave portion of the roll surface of the coating roll is transferred to the surface of the separator, the range over which the adhesive is transferred can be easily set to the width of the separator. Can be limited to
It is possible to prevent the adhesive from protruding and contaminating a roll or the like that transports the separator. Also, since the adhesive is transferred to the surface of the separator according to the pattern of the concave portion provided on the roll surface of the coating roll, unlike the case where the adhesive is transferred without a gap over the entire surface, the porous film of the separator is It is possible to reduce the amount of the solvent that passes through to the back side. Further, since the adhesive in the concave portion of the coating roll is transferred to the surface of the separator, the separator is not rubbed with the coating roll and an unreasonable force is applied only by lightly pressing.

According to a second aspect of the invention, there is provided a method of manufacturing a battery, wherein a separator is wound on the roll surfaces of two transport rolls spaced apart from each other and transported, and the separator is transported between the two transport rolls. An adhesive is sequentially transferred to the surface, and the separator is bonded to the electrode by superimposing the surface of the electrode on the surface of the separator to which the adhesive has been transferred.

According to the invention of claim 2, the separator is:
Since the adhesive is transferred to the front surface between the two transport rolls, the back side of this transfer position is open, so that no excessive force is applied to the separator, and the possibility of breakage can be prevented. Become like

According to a third aspect of the present invention, the adhesive is sequentially supplied to the roll surface with the rotation of the coating roll, and the roll surface of the coating roll to which the adhesive has been supplied is removed from the roll surface. The adhesive is sequentially transferred to the surface of the separator by pressing against the surface of the separator conveyed in the direction opposite to the rotational movement of the roll surface of the coating roll between the book transport rolls.

According to the third aspect of the present invention, as in the prior art,
The adhesive is transferred when the surface of the separator rubs against the roll surface of the coating roll that rotates in the reverse direction.However, this separator rubs against the roll surface of the coating roll with the back side open, so that excessive force is applied. Is not added, and the possibility of breakage can be prevented.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the first embodiment of the present invention and is a side view schematically showing a step of applying an adhesive to a separator. Components having the same functions as those of the conventional example shown in FIG. 3 are denoted by the same reference numerals.

In this embodiment, a method of applying an adhesive to the separator of the polymer battery described in the conventional example and bonding the separator to the negative electrode will be described. The coater (coating machine) used in the present embodiment is provided with a concave portion 1a on the roll surface of the coating roll 1 which rotates on a rotation axis in a horizontal direction (a direction perpendicular to the drawing) counterclockwise in the drawing. . This recess 1a
Is arbitrary, for example, a pattern in which a large number of grooves are arranged or crossed in parallel, or a pattern in which holes are dotted.

A large amount of adhesive 2 is stored on the roll surface facing upward from the coating roll 1. As the adhesive 2, a material obtained by adding a solvent such as DMF (dimethylformamide) to PVDF (polyvinylidene fluoride) or the like is used. Then, the adhesive 2 on the roll surface of the coating roll 1 which is directed downward by rotation is dammed by the blade 3 arranged diagonally above and to the left of the coating roll 1 in the drawing, so that the blade 3 is inserted into the concave portion 1a provided on the roll surface. Only the adhesive 2 is sequentially supplied. In addition, the back side of the separator 4 is laid over the roll surface of the back roll 5 rotating in the opposite direction on a parallel rotation axis located at the same height position as the coating roll 1, and from above the back roll 5 to above. It is conveyed toward. In addition, the back roll 5 is configured such that the surface of the separator 4 conveyed on the roll surface is lightly pressed against the right roll surface of the coating roll 1 in the drawing. For this reason, a roll surface that faces upward from the coating roll 1,
Since the surface of the separator 4 conveyed upward on the roll surface of the back roll 5 contacts while moving in the same direction, the adhesive 2 in the concave portion 1a provided on the roll surface of the coating roll 1 is sequentially separated from the separator 4. Is transferred to the surface of Such transfer is easily performed if the adhesiveness of the surface of the separator 4 to the adhesive 2 is sufficiently high as compared with the inner surface of the concave portion 1a.

The adhesive 2 transferred to the surface of the separator 4
Since the pattern of the concave portion 1a provided on the roll surface of the coating roll 1 is repeated, the concave portion 1a is provided only within the range of the width of the separator 4, so that unnecessary portions at both ends of the back roll 5 are unnecessary. The adhesive 2 does not adhere to the substrate. Also, since the adhesive 2 is not applied to the entire surface of the separator 4,
The amount of solvent that seeps through the porous film of the separator 4 to the back surface is also reduced, and the roll that transports the separator 4 in the subsequent process is hardly stained.

When the adhesive 2 is transferred to the surface of the separator 4 in an appropriate pattern in this manner, the surface of the negative electrode (not shown) is superimposed on the surface of the separator 4 and pressed by a nip roll. To the negative electrode. At this time, the adhesive 2 is pressed by the negative electrode and spreads around, so that it spreads over the entire surface of the separator 4 to have a uniform thickness. Therefore, coating roll 1
It is preferable that the pattern of the concave portions 1 a is distributed as uniformly as possible within the range of the width of the separator 4. Actually, another separator coated with an adhesive by a coater having a similar configuration (not shown) is simultaneously bonded to the back surface of the negative electrode.

As described above, according to the present embodiment, only the adhesive 2 in the concave portion 1a provided on the roll surface of the coating roll 1 is transferred to the surface of the separator 4, so that both ends of the back roll 5 This prevents unnecessary adhesive 2 from adhering to the portion, and a roll or the like that transports the separator 4 in a subsequent step from being stained by the solvent. Further, since the separator 4 comes into contact with the roll surface of the coating roll 1 while moving in the same direction, there is no possibility that the separators 4 rub against each other to apply an excessive force and break.

FIG. 2 shows a second embodiment of the present invention and is a side view schematically showing a step of applying an adhesive to a separator. Note that the same reference numerals are given to constituent members having the same functions as those of the first embodiment shown in FIG.

This embodiment also describes a method of applying an adhesive to the separator of the polymer battery described in the conventional example and bonding the separator to the negative electrode. The coater used in this embodiment is:
A coating roll 1 having the same configuration as the conventional example is used. That is, the coating roll 1 rotating clockwise in the drawing on the rotation axis in the horizontal direction (perpendicular to the drawing), a large amount of the adhesive 2 is stored on the roll surface facing upward. ing. Then, the adhesive 2 is limited to a certain thickness by the comma roll 7 and is sequentially supplied onto the roll surface of the coating roll 1 which is directed downward by rotation.

The separator 4 is conveyed upward from below, with its back surface wrapped around the roll surfaces of two conveying rolls 6 and 6 rotating in the same direction as the coating roll 1 arranged vertically apart. . These transport rolls 6 and 6 are arranged so that the surface of the separator 4 stretched between them is lightly in contact with the roll surface on the right side of the coating roll 1 in the drawing. For this reason, the surface of the separator 4 conveyed upward rubs against the roll surface of the coating roll 1 facing downward, so that the adhesive 2 supplied on this roll surface is applied to the surface of the separator 4 by a constant amount. It can be transferred in thickness. Moreover, the separator 4 is not pressed by the back roll 5 from the back side as in the case of the conventional example, and the surface of the separator 4 rubs against the roll surface of the coating roll 1 with the back side opened. In addition, no excessive force is applied to the separator 4.

As described above, according to the present embodiment, the separator 4 comes into contact with the roll surface of the coating roll 1 at the position where the back side between the two transport rolls 6 and 6 is open, so that the separator 4 It will not be broken by excessive force.

In the present embodiment, the case where the coating roll 1 having the same configuration as that of the conventional example is used has been described. However, the method of supplying the adhesive 2 is optional. It is also possible to use a supply device that supplies 2 uniformly and sequentially. In this case, the front surface of the separator 4 comes into contact with and rubs against the tip of the nozzle, but since the rear surface is open, there is no possibility that excessive force will be applied. Further, in the present embodiment, the case where both the back surfaces of the separators 4 are wrapped between the transport rolls 6 and 6 has been described. The roll 6 can be wound on the front side of the separator 4.

In the first and second embodiments, the method of applying the adhesive 2 to the separator 4 of the polymer battery has been described. However, in order to attach the separator to the electrode, the adhesive is applied to the separator. Battery,
The present invention can be similarly applied to a method of manufacturing another type of battery.
The electrode to which the separator is bonded is not limited to the negative electrode, but may be the positive electrode.

[0028]

As is apparent from the above description, according to the battery manufacturing method of the present invention, the adhesive is transferred onto the surface of the separator in an appropriate pattern. No more mess. Also,
The adhesive in the concave portion provided on the coating roll is transferred to the surface of the separator, or the adhesive is transferred to the surface of the separator with the back side open, so that excessive force is applied to this separator and the separator breaks. Disappears.

[Brief description of the drawings]

FIG. 1, showing the first embodiment of the present invention, is a side view schematically showing a step of applying an adhesive to a separator.

FIG. 2, showing a second embodiment of the present invention, is a side view schematically illustrating a step of applying an adhesive to a separator.

FIG. 3, which shows a conventional example, is a side view schematically showing a step of applying an adhesive to a separator.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 coating roll 1a recess 2 adhesive 4 separator 5 back roll 6 transport roll

Claims (3)

[Claims] An adhesive is sequentially supplied into a concave portion provided on a roll surface with the rotation of a coating roll, and a surface of a separator is attached to a roll surface supplied with an adhesive in a concave portion of the coating roll. By sequentially pressing, the adhesive in the concave portion is transferred to the surface of the separator, and the separator is bonded to the electrode by overlapping the surface of the electrode on the surface of the separator to which the adhesive has been transferred. Battery manufacturing method. 2. The method according to claim 1, wherein the separator is wound on the roll surfaces of two transport rolls spaced apart from each other and transported, and the adhesive is sequentially transferred to the surface of the separator transported between the two transport rolls. A method for producing a battery, comprising: bonding a separator to an electrode by superposing the surface of the electrode on the surface of the separator to which the adhesive has been transferred. 3. An adhesive is sequentially supplied to the roll surface with the rotation of the coating roll, and the roll surface of the coating roll to which the adhesive is supplied is moved between the two transport rolls by the coating roll. 3. The method according to claim 2, wherein the adhesive is sequentially transferred to the surface of the separator by pressing against the surface of the separator that is conveyed in a direction opposite to the rotational movement of the roll surface.