KR20160079635A - Method of manufacturing battery - Google Patents

Abstract

The present invention provides a manufacturing method of a battery, comprising: a preparation process of arranging a battery main body part (23) in a bag body which is a square shape when planarized, and preparing a temporal seal member (30) having a remaining first side part (34) as an opened opening (24) while three side parts of four side parts around the battery main body part of the bag body are sealed; an injection process of arranging the temporal seal member in a state of facing the opening (24) upward and opening the same, and injecting electrolyte into the battery main body part (23) by arranging an upper end of an electrolyte injection nozzle (40) immediately above the opening (24) or inserting the upper end thereof through the opening (24); a primary sealing process of forming a first sealing part by sealing the opening (24) with heat by using a first heat seal while deaerating the temporal seal member after the injection process; and a secondary sealing process of pressing the first sealing part with heat by using a second heat seal after the deaeration. According to the manufacturing method, enough sealing strength can be secured, thereby preventing each heat seal from being delaminated and manufacturing a battery having excellent productivity.

Description

[0001] METHOD OF MANUFACTURING BATTERY [0002]

The present invention relates to a method for manufacturing a laminate type secondary battery such as a laminate lithium ion secondary battery laminated with a casing.

Description of the Related Art [0002] In recent years, as mobile electrical appliances such as smart phones and tablet terminals have become thinner and lighter in weight, they have been used as exterior materials for electric storage devices such as lithium ion secondary batteries, lithium polymer secondary batteries, lithium ion capacitors, A laminate composed of a heat resistant resin layer / adhesive layer / metal foil layer / adhesive layer / thermoplastic resin layer (inner layer) is used in place of the conventional metal can.

Examples of the method for producing such a casing include a lithium battery cell formed by a flexible casing in which a lithium battery main body is housed and an inner layer made of at least a substrate layer, an aluminum foil, a chemical conversion treatment layer, A method of thermally sealing an opening portion of an external body, the method comprising: a first step of heating and drying a portion of the opening portion where the heat sealing portion is formed to a temperature lower than the melting point of the thermally adhesive resin forming the inner layer; And a second step of thermally sealing the portion of the battery case by heat bonding by means of a heat-bonding means (see Patent Document 1).

Patent Document 1: Japanese Patent Application Laid-Open No. 2006-261033

However, in the above-described method, since the first step of heating and drying the electrolytic solution adhering to the planned seal portion is provided before the second step of performing the heat seal, there is a problem that the productivity is poor. In particular, since the adhered electrolyte is heated and dried at a temperature lower than the melting point of the thermally adhesive resin forming the inner layer, it takes time to heat and dry.

Further, if the time for heating and drying by vacuum is long, the amount of the electrolytic solution adhering to the heat sealable portion is increased, so that the amount of electrolyte contaminants in the heat seal portion is increased.

SUMMARY OF THE INVENTION The present invention has been made in view of such a technical background, and it is an object of the present invention to provide a method of manufacturing a battery, which can secure a sufficient yarn strength so as to prevent occurrence of delamination at a heat- .

In order to achieve the above object, the present invention provides the following means.

[1] A battery pack according to any one of [1] to [3], wherein a battery body portion is disposed inside a substantially rectangular bag-shaped bag body formed of a heat-resistant resin layer as an outer layer, a thermoplastic resin layer as an inner layer, and a metal foil layer disposed between both layers, Preparing a temporary seal member having three sides of four sides near the periphery of the battery body portion in the bag body sealed and the remaining one side portion being formed with an opening portion;

The tip of the nozzle for injecting the electrolyte is disposed at a position directly above the opening or inserted into the opening to inject the electrolyte solution into the battery main body part, ,

A first sealing step of sealing the opening portion with a first heat seal bar to form a first seal portion while degassing the interior of the temporary seal member using a deaerator,

And a second sealing step of applying heat and pressure to the first seal part using a second heat seal bar after the deaeration is completed.

[2] The method according to any one of [1] to [4], wherein the temperature of the first heat seal bar at the time of heat sealing in the first sealing step is set to a temperature equal to or higher than the melting point of the thermoplastic resin layer,

The method of manufacturing a battery according to claim 1, wherein the temperature of the second heat seal bar at the time of heat sealing in the second sealing step is set to a temperature equal to or higher than the melting point of the thermoplastic resin layer.

[3] The thermoplastic resin layer of the temporary seal member has a multilayer structure including a low melting point thermoplastic resin layer disposed on the inner surface side and a high melting point thermoplastic resin layer disposed on the metal foil layer side,

The temperature of the first heat seal bar at the time of heat sealing in the first sealing step is set to a temperature equal to or higher than the melting point of the low melting point thermoplastic resin layer,

Wherein the temperature of the second heat seal bar at the time of heat sealing in the second sealing step is set to a temperature equal to or higher than the melting point of the low melting point thermoplastic resin layer.

[4] In the first sealing step and / or the second sealing step, the inner contact surfaces are formed in a pair of heat sealing chambers, each of which is formed in a curved shape in which a central portion in the longitudinal direction and / The method for manufacturing a battery according to any one of items 1 to 3 above, wherein the bar is used.

[5] A method for manufacturing a battery as described in any one of [1] to [4], wherein a pair of heat seal bars having a porous sheet disposed on an inner contact surface in the first and second sealing processes are used.

[6] One of the three sides sealed in the temporary seal member is one of the items 1 to 5 of the items (1) to (5), wherein the exterior material is sealed by bending formed by folding in two with the inner layer inward By weight based on the total weight of the battery.

According to the invention of [1], since the heat chamber (final heat chamber) of the remaining one side portion (opening portion) of the temporary seal member is divided into two or more plural circuits, the time required for one final heat chamber Seconds) can be distributed to each of the first chamber process and the second chamber process, so that the heat room time of each of the first chamber process and the second chamber process is shorter than N seconds (for example, 0.5 N Sec, 0.7N sec, 0.8N sec, etc.), whereby the processing time can be shortened and the productivity can be improved. For example, after the first chamber process using the degassing apparatus or the like is terminated at a shortened time, the temporary chamber member after completion is sent to the next chamber chamber, and the degassing apparatus or the like is moved to the next work ), It is possible to shorten the process time (it is possible to shorten the tact time per process).

In addition, in the conventional method, since the final heat seal is performed once, a long heat seal time is required. Therefore, the heat quantity (temperature) transferred to the battery main body or the like is large and the electrolytic solution is decomposed, There is a risk of deterioration. On the other hand, according to the present invention, since the heat chamber is divided into two or more circuits in a plurality of circuits, the amount of heat (temperature) transferred to the battery main body portion and the like is not excessively increased and the electrolytic solution is decomposed none.

In addition, since the heat chamber is divided into a plurality of the heat seals in two or more times, the time (degassing time) of the first sealing step for performing the heat sealing while degassing can be shortened, It is possible to reduce the liquid amount, thereby realizing a good heat seal bonding (ensuring sufficient room strength) and preventing the occurrence of delamination of the seal part.

In addition, since the heat chamber is divided into a plurality of two or more circuits, for example, the actual facilities of the first actual process (actual facilities provided with the degassing facility) and the actual facilities of the second actual process can be respectively dedicated , Different conditions can be set in the two actual processes, optimal conditions can be set for each of the two actual processes, and a battery with excellent reliability can be manufactured.

In the invention of [2], it is possible to secure a sufficient yarn strength and to sufficiently prevent the occurrence of delamination of the seal portion.

According to the invention of [3], it is possible to improve the heat property in the first sealing step of performing the heat sealing while degassing, and to prevent the occurrence of defects such as cracking and deformation in the heat sealing part.

According to the inventions of [4] and [5], since the heat seal bonding can be performed while escaping the electrolytic solution to the peripheral side even if the electrolytic solution adheres to the opening portion to be hit and / or the first seal portion, A more favorable heat seal bonding that can be ensured can be realized, and the occurrence of delamination of the seal portion can be sufficiently prevented.

In the invention of [6], in the step of preparing the temporary seal member, one side of the three sealed sides is sealed by the bending portion folded in two instead of the actual seal, so that the productivity can be further improved .

Fig. 1 is a front view for explaining the first half of the manufacturing method according to the present invention. Fig. 1 (A) is a cross-sectional view showing a state in which an opening of the upper side (second adjacent side) (B) is a state in which an electrolyte is injected by using an electrolyte injection nozzle, and (C) is a state in which an opening at an upper end of the gas chamber is sealed to form a sealing bag.
Fig. 2 is a front view for explaining the second step of the manufacturing method according to the present invention, wherein (A) shows a state in which the electrolyte solution is infiltrated into the electrode material by the chemical conversion treatment, (B) (C) shows a state in which a gas chamber portion is removed by trimming to obtain a laminated battery, respectively.
3 is a cross-sectional view showing a state in which a heat seal is performed directly on a pair of heat chambers.
Fig. 4 is a cross-sectional view showing another example of a state in which a pair of heat chambers directly perform heat seals. Fig.
5 is a sectional view showing an example of a casing used in the manufacturing method of the present invention.

A method of manufacturing a battery according to the present invention will be described with reference to the drawings. The outer sheath 1 used in the manufacturing method of the present invention includes a heat resistant resin layer 2 as an outer layer, a thermoplastic resin layer 3 as an inner layer, and a metal foil layer 4 disposed between both layers (See Fig. 5). For example, the heat-resistant resin layer (outer layer) 2 is laminated and integrated on one surface of the metal foil layer 4 with the first adhesive layer 5 interposed therebetween. On the other surface of the metal foil layer 4, (1) in which a thermoplastic resin layer (inner layer) 3 is laminated and integrated through an adhesive layer 6 (see Fig. 5).

The thermoplastic resin layer 3 may be formed in a single layer or in a multiple layer. Among them, the thermoplastic resin layer 3 is composed of a low melting point thermoplastic resin layer disposed on the inner surface side and a thermoplastic resin layer disposed on the metal foil layer 4 side (on the metal foil layer 4 side of the low melting point thermoplastic resin layer) Layer structure having two or more layers including a melting point thermoplastic resin layer. Details of the low melting point thermoplastic resin layer and the high melting point thermoplastic resin layer will be described later. The "low melting point thermoplastic resin" means a thermoplastic resin having a melting point of 120 ° C. to 155 ° C., and the "high melting point thermoplastic resin" means a thermoplastic resin having a melting point higher than the melting point of the low melting point resin. As the high melting point resin, it is preferable to use a resin having a melting point higher than the melting point of the low melting point thermoplastic resin and a melting point of the high melting point resin of 135 占 폚 to 185 占 폚.

The battery body portion 23 is disposed inside the substantially rectangular bag body when the battery pack 1 is constructed in the above-described manner, and three out of four sides in the vicinity of the battery body portion 23 in the bag body And the other one of the side edges 34 is sealed with the openings 24 opened at the one side edge portion 34 without being actually bonded to the facing face front face portion 21 and the facer back face portion 22. [ (See Fig. 1 (A)).

The temporary seal member 30 has a substantially rectangular outer casing front face portion 21 formed by folding the inner casing 3 inwardly at an intermediate position in the longitudinal direction of the casing member 1 in a rectangular shape in plan view, A rectangular battery body portion 23 is disposed between the battery case 20 and the exterior material backing portion 22 on the top. 1, reference numeral 31 denotes a bent side (bent portion). The battery main body 23 is disposed in a lower half portion of a space between the casing front portion 21 and the outer casing rear portion 22 (see Fig. 1 (A)). The facing facade front portion 21 and the facer material back facet portion 22 are joined to each other by a heat seal or the like at the opposite side edge portion 32 facing the folded bent side 31 to form the opposite side face portion 35. [

The positive electrode tab lead 11 and the negative electrode tab lead 12 extend outward from one side (opposite side) 32 of the battery body portion 23 (see FIG. 1 (A)). Thus, in the present embodiment, the facing surface front portion 21 and the facing material back surface portion 22 of the opposite side edge portion 32 sandwich the positive electrode tab lead 11 and the negative electrode tab lead 12, So that the opposite side portion 35 is formed (see Fig. 1 (A)). The distal end portion of the positive electrode tab lead 11 is led out to the outside, and the tip end portion of the negative electrode tab lead 12 is led to the outside. The battery body portion 23 includes a positive electrode material, a negative electrode material, and an electrolyte as constituent elements. At this stage, the electrolyte solution is not yet injected. A positive electrode tab lead 11 is connected to the positive electrode material, and a negative electrode tab lead 12 is connected to the negative electrode material.

Out of the four sides 31, 32, 33, and 34 of the bag body near the periphery of the battery body portion 23 at one first adjacent side edge 33 adjacent to the bent side 31, 21 and the facer back portion 22 are joined together by a heat seal or the like to form a first adjacent side portion 36 (see Fig. 1 (A)). Among the four sides 31, 32, 33, and 34 in the vicinity of the periphery of the battery body portion 23 in the bag body, the other second adjacent side edge 34 adjacent to the bent side 31, And an opening 24 (see Fig. 1 (A)). In Fig. 1, the internal space 41 above the second abutting edge 34 in the temporary seal member 30 is referred to as a " gas chamber ".

Next, as shown in Fig. 1 (B), the temporary seal member 30 is disposed in a state in which the second abutting edge portion 34 is disposed above the first abutting edge portion 33, That is, the temporary seal member 30 is disposed in a standing state with the opening portion 24 disposed above the first adjacent side surface portion 36, and the tip end of the electrolyte injection nozzle 40 is positioned on the side of the opening portion 24 The electrolyte solution is injected into the battery body portion 23 by inserting the electrolyte solution into the opening portion 24 as shown in FIG. 1 (B) (injection step).

The electrolytic solution is not particularly limited. For example, a solution obtained by dissolving a lithium salt of hexafluoride to a concentration of 1 mol / l in a mixed solvent obtained by mixing ethylene carbonate and diethylene carbonate at a volume ratio of 1: 1 (Electrolytic solution).

Subsequently, an opening at the upper end of the gas chamber 41 in the temporary seal member 30 is heat-sealed to form a gas-room upper end seal portion 37 to form a sealing bag (see Fig. 1 (C)).

It is preferable that the injection step and the sealing bag forming step are performed in a dry room in order to make the laminate battery to have a reduced life as much as possible and to make the life of the laminated battery long. The conditions in the dry room include, for example, a range of a dew point of "-40 ° C" to "-60 ° C".

Next, the sealing bag (temporary sealing member) 30 is placed in the chemical conversion processing vessel 50 to perform a chemical conversion treatment so that the electrolyte solution is infiltrated into the electrode material (positive electrode material and negative electrode material) (Fig. 2 A)). As the chemical conversion treatment, for example, the following treatments can be mentioned. First, after being left at room temperature, it is placed in an atmosphere of 40 ° C to 60 ° C to lower the viscosity of the electrolytic solution and to allow the electrolytic solution to penetrate (penetrate) into the electrode material (electrode active material or the like). Next, pressurization, initial charging, and pressure degassing in a high temperature (40 DEG C to 60 DEG C) atmosphere are performed from the top surface of the portion corresponding to the laminate battery.

Then, while the deaeration (vacuum degassing or the like) of the inside of the sealing bag (temporary sealing member) 30 is performed using a degassing apparatus, the second adjacent side edge portion (The heat seal example) 24 of the first heat seal member 34 is heat-sealed by using the first heat seal bar to form the first seal member (first seal process). The heat sealing time in the first sealing step is not particularly limited, but is preferably set to 4 to 8 seconds.

Next, after the first sealing step, that is, after the completion of the degassing, the first sealing portion is further heated and pressed using the second heat sealing bar to form a second adjacent side portion (a plurality of portions 2) 7 2 (B)) and the sealing with the casing member 1 is completed (second sealing step). The heat sealing time in the second sealing step is not particularly limited, but is preferably set to 3 seconds to 9 seconds.

The temperature of the first heat seal bar at the time of heat sealing of the opening portion 24 in the first sealing step is set at a temperature equal to or higher than the melting point of the thermoplastic resin constituting the thermoplastic resin layer 3 ). In particular, it is particularly preferable that the temperature of the first heat seal bar is set to a temperature 10 ° C to 40 ° C higher than the melting point of the thermoplastic resin constituting the thermoplastic resin layer (3). In the second sealing step, the temperature of the second heat seal bar at the time of heating and pressing is set to a temperature equal to or higher than the melting point of the thermoplastic resin constituting the thermoplastic resin layer (a temperature equal to or higher than the melting point) . In particular, it is particularly preferable that the temperature of the second heat seal bar is set at a temperature higher than the melting point of the thermoplastic resin constituting the thermoplastic resin layer (3) by 10 ° C to 40 ° C.

The thermoplastic resin layer 3 includes a low melting point thermoplastic resin layer disposed on the inner surface side and a high melting point thermoplastic resin layer disposed on the metal foil layer 4 side (on the metal foil layer 4 side of the low melting point thermoplastic resin layer) In the case of employing a two-layer structure or two-layer structure including a thermoplastic resin layer, it is preferable to set the following conditions in the first sealing step and / or the second sealing step. That is, in the first sealing step, the temperature of the first heat seal bar at the time of performing the heat seal is set at a temperature equal to or higher than the melting point of the low melting point thermoplastic resin layer (at the same temperature as the melting point of the low melting point thermoplastic resin layer, Temperature higher than the melting point). Among them, it is particularly preferable to set the temperature of the first heat seal bar at a temperature higher than the melting point of the low melting point thermoplastic resin by 10 ° C to 40 ° C. In the second sealing step, the temperature of the second heat seal bar at the time of heating and pressing is set at a temperature equal to or higher than the melting point of the low melting point thermoplastic resin layer (the same temperature as the melting point of the low melting point thermoplastic resin layer, Temperature higher than the melting point). In particular, it is particularly preferable that the temperature of the second heat seal bar is set to a temperature higher than the melting point of the low melting point thermoplastic resin by 10 ° C to 40 ° C.

It is preferable to use the heat seal bar shown in Figs. 3 and 4 in the first seal process and the second seal process.

In the heat seal bar 43 shown in Fig. 3, the inner contact surface 44 is formed in a curved shape in which the central portion in the longitudinal direction of the heat seal bar protrudes (the central portion is convex). In the case of performing the heat seal of the opening portion 24 of the second adjacent side edge portion 34 by using the pair of heat seal bars 43 having the above-described configuration, even if the electrolyte solution adheres to the opening portion 24 to be hit The heat seal bonding can be performed while the electrolytic solution is escaped to the peripheral side, so that a high thread strength can be secured. The heat seal bar 43 may be formed in a curved shape in which the central portion in the width direction of the heat seal bar protrudes (the central portion is convex). The heat seal bar 43 may be formed in a curved shape in which a central portion in the longitudinal direction and the width direction of the heat seal bar protrudes (the central portion is convex). The shape of the curved shape is not particularly limited, but may be, for example, an arc shape.

In the heat seal bar 46 shown in Fig. 4, the porous sheet 48 is disposed on the inner contact surface. In this embodiment, both end portions of the porous sheet 48 are bonded and fixed to both sides of the heat seal bar 46, respectively. In the case of performing the heat seal of the opening portion 24 of the second adjacent edge portion 34 by using the pair of the heat seal bars 46 having the above-described configuration, even if the electrolyte solution adheres to the opening portion 24 to be hit It is possible to perform the heat seal bonding while escaping the electrolytic solution to the peripheral side, so that high yarn strength can be ensured. The porous sheet 48 is not particularly limited, and examples thereof include a mesh sheet, a glass cloth sheet, a nonwoven fabric sheet, and an embossed sheet. Examples of the material of the mesh sheet, the nonwoven fabric sheet and the embossed sheet include, but are not limited to, polyester resin, polyimide resin, fluorine resin (polytetrafluoroethylene), glass (glass cloth, etc.) And a composite material of fluororesin (polytetrafluoroethylene, etc.).

Next, a portion (generally upper half) corresponding to the gas chamber 41 in the sealing bag 30 is removed by trimming to obtain the laminate battery 10 shown in Fig. 2 (C). The laminate battery 10 is sealed in all four sides 31, 32, 33, 34 near the periphery of the battery body portion 23 in the external body 1 (see Fig. 2 (C) .

Next, the exterior member 1 used in the manufacturing method of the present invention will be described in detail.

As the heat-resistant resin constituting the heat-resistant resin layer (outer layer) 2, a heat-resistant resin which does not melt at the heat room temperature at the time of heat sealing is used. As the heat resistant resin, it is preferable to use a heat resistant resin having a melting point higher than the melting point of the thermoplastic resin constituting the thermoplastic resin layer (3) by at least 10 DEG C, and a heat resistant resin having a melting point higher than the melting point of the thermoplastic resin by 20 DEG C or more It is more preferable to use it. Among them, it is more preferable to use a heat resistant resin having a melting point higher than the melting point of the thermoplastic resin constituting the thermoplastic resin layer (3) by 40 占 폚, more preferably 50 占 폚 or more It is particularly preferable to use a heat-resistant resin having a high melting point.

When the thermoplastic resin layer 3 comprises a low melting point thermoplastic resin layer disposed on the inner surface side and a high melting point thermoplastic resin layer disposed on the metal foil layer 4 side, It is preferable to use a heat resistant resin having a melting point higher than the melting point of the low melting point thermoplastic resin constituting the thermoplastic resin layer 3 by 10 DEG C or more and to use a heat resistant resin having a melting point of 20 DEG C or more higher than the melting point of the low melting point thermoplastic resin . Among them, it is more preferable to use a heat-resistant resin having a melting point higher than the temperature of 40 占 폚 higher than the melting point of the low melting point thermoplastic resin constituting the thermoplastic resin layer (3). The melting point of the low melting point thermoplastic resin It is particularly preferable to use a heat-resistant resin having a melting point higher than 50 캜.

The heat resistant resin layer (outer layer) 2 is not particularly limited, and for example, a polyamide film such as a nylon film, a polyester film, and the like are preferably used. As the heat resistant resin layer 2, a biaxially oriented polyamide film such as a biaxially oriented nylon film, a biaxially oriented polybutylene terephthalate (PBT) film, a biaxially oriented polyethylene terephthalate (PET) film, or a biaxially oriented poly It is particularly preferred to use a biaxially oriented polyethylene naphthalate (PEN) film. The nylon film is not particularly limited, and examples thereof include 6 nylon film, 6,6 nylon film, and MXD nylon film. The heat resistant resin layer 2 may be formed of a single layer or may be formed of a multilayer (eg, PET film / nylon film multilayer) formed of a polyester film / polyamide film.

The thickness of the heat resistant resin layer 2 is preferably 5 to 80 탆. By setting the upper limit to a value not lower than the appropriate lower limit value, sufficient strength can be ensured as an outer sheath, and by setting the upper limit to the appropriate upper limit or less, the stress during molding such as extrusion molding and drawing molding can be reduced and moldability can be improved.

The thermoplastic resin layer (inner layer) 3 has excellent chemical resistance against an electrolyte or the like having high corrosivity, which is used in a lithium ion secondary battery or the like, and plays a role of imparting heat resistance to the casing.

The thermoplastic resin layer 3 is not particularly limited, but is preferably a thermoplastic resin undrawn film layer. The thermoplastic resin non-stretched film layer 3 is formed of at least one thermoplastic resin selected from the group consisting of polyethylene, polypropylene, olefin-based copolymer, acid-modified product thereof and ionomer thereof, It is preferable that it is constituted by an unstretched film.

The thermoplastic resin layer 3 includes a low melting point thermoplastic resin layer disposed on the inner surface side and a high melting point thermoplastic resin layer 3 disposed on the metal foil layer 4 side (on the metal foil layer 4 side of the low melting point thermoplastic resin layer) Layer structure having two or more layers including a ground layer. In this case, the low melting point thermoplastic resin layer is not particularly limited, and examples thereof include polypropylene, polyethylene, a propylene-ethylene copolymer (random polypropylene), an olefin-based copolymer, an acid- Examples of the high melting point thermoplastic resin layer include homopolypropylene, polyethylene, propylene-ethylene copolymer (random polypropylene), olefin-based copolymer, and acid-modified And an ionomer.

The thickness of the thermoplastic resin layer 3 is preferably set to 20 to 80 탆. By setting the thickness to 20 mu m or more, the occurrence of pinholes can be sufficiently prevented, and by setting the thickness to 80 mu m or less, the amount of resin used can be reduced and the cost can be reduced. In particular, it is particularly preferable that the thickness of the thermoplastic resin layer 3 is set to 30 탆 to 50 탆. The thermoplastic resin layer 3 may be a single layer or a multilayer.

The metal foil layer 4 plays a role of imparting gas barrier properties to the exterior material 1 so as to prevent the intrusion of oxygen and moisture. The metal foil layer 4 is not particularly limited, and examples thereof include aluminum foil, copper foil and SUS foil (stainless steel foil). Aluminum foil and SUS foil are generally used. As the material of the aluminum foil, A8079-O material and A8021-O material are preferable. The thickness of the metal foil layer 4 is preferably 15 to 80 탆. It is possible to prevent the occurrence of pinholes at the time of rolling at the time of producing the metal foil and to reduce the stress at the time of forming such as extrusion forming and drawing forming by being 80 탆 or less, .

It is preferable that the metal foil layer 4 is subjected to chemical conversion coating on at least the inner side (the side of the second adhesive layer 6). Since such chemical conversion treatment is carried out, the corrosion of the surface of the metal foil by the contents (electrolytic solution of the battery, etc.) can be sufficiently prevented. For example, the metal foil is subjected to the chemical conversion coating by the following process. That is, for example, on the surface of the metal foil after the degreasing treatment,

1) phosphoric acid,

Chromic acid,

An aqueous solution of a mixture containing at least one compound selected from the group consisting of metal salts of fluorides and non-metal salts of fluorides

2)

At least one resin selected from the group consisting of an acrylic resin, a chitosan derivative resin and a phenol resin,

An aqueous solution of a mixture containing at least one compound selected from the group consisting of chromic acid and chromium (III) salts

3)

At least one resin selected from the group consisting of an acrylic resin, a chitosan derivative resin and a phenol resin,

At least one compound selected from the group consisting of chromic acid and chromium (III) salt,

An aqueous solution of a mixture containing at least one compound selected from the group consisting of metal salts of fluorides and non-metal salts of fluorides

After applying any of the aqueous solutions of 1) to 3) above, the film is subjected to a chemical conversion treatment by drying.

The above-mentioned chemical conversion film is preferably from 0.1 mg / m 2 to 50 mg / m 2, particularly preferably from 2 mg / m 2 to 20 mg / m 2 as the chromium adhering amount (per one side).

The first adhesive layer 5 is not particularly limited, and examples thereof include a polyurethane adhesive layer, a polyester polyurethane adhesive layer, and a polyether polyurethane adhesive layer. The thickness of the first adhesive layer 5 is preferably set to 1 탆 to 5 탆. In particular, from the viewpoint of thinning and lightening of the exterior material, it is particularly preferable that the thickness of the first adhesive layer 5 is set to 1 탆 to 3 탆.

Although the second adhesive layer 6 is not particularly limited, for example, those exemplified as the first adhesive layer 5 may be used, but it is preferable to use a polyolefin-based adhesive having a small expansion caused by an electrolytic solution Do. The thickness of the second adhesive layer 6 is preferably set to 1 탆 to 5 탆. Particularly, from the viewpoint of thinning and lightening of the exterior material, it is particularly preferable that the thickness of the second adhesive layer 6 is set to 1 탆 to 3 탆.

In the manufacturing method of the present invention, as the casing member 1, even if a molding case (a case having a shape capable of housing the battery body portion 23) is used by molding (deep drawing molding, injection molding or the like) It may be used as it is, and it may be used as it is not provided for molding.

In the above embodiment, the temporary seal member 30 is formed by folding one sheet of the envelope 1 in two, but the present invention is not particularly limited to this configuration. For example, It is also possible to use a temporary seal member 30 constructed so that the inner layer 3 is on the inner surface (so that the inner layer 3 is in contact with each other).

Example

Next, specific examples of the present invention will be described, but the present invention is not limited to these examples.

<Example 1>

A chemical conversion coating liquid composed of phosphoric acid, polyacrylic acid, a trivalent chromium compound, water, and alcohol was applied to both surfaces of an aluminum foil (A8021-O material) 4 having a thickness of 35 탆 and dried at 180 캜, To form a film. The deposition amount of chromium in this chemical conversion coating is 10 mg / m 2 per one side.

Next, a biaxially oriented polyethylene terephthalate (PET) film having a thickness of 25 占 퐉 was laminated on one surface of the chemically coated aluminum foil 4 with a two-liquid curing type urethane adhesive (first adhesive layer) (Melting point: 230 DEG C) (2) was dry laminated (stitched).

Next, an adhesive liquid was applied to the other surface of the aluminum foil 4 using a gravure roll, and then dried by hot air at 80 DEG C to form an adhesive resin layer (second adhesive layer) 6 ). 15 parts by mass of a maleic acid-modified polypropylene (a modified polypropylene resin obtained by graft-polymerizing maleic anhydride on a copolymer of propylene and ethylene at a melting point of 80 ° C) as the above-mentioned adhesive liquid was mixed in a mixed solvent (toluene / methyl ethyl ketone = 8 mass Part / 2 parts by mass of a mixed solvent), 0.9 parts by mass of a polymer body of hexamethylene diisocyanate was used.

Next, an ethylene-propylene copolymer resin layer (low melting point thermoplastic resin layer) (3) having a thickness of 20 占 퐉 and a melting point of 145 占 폚 and a homopolypropylene resin layer having a melting point of 165 占 폚 (3) is co-extruded by using a T-die to form a laminated film in which these two layers are laminated, and then immediately after this co-extrusion, the surface of the high melting point thermoplastic resin layer of the laminated film is, The aluminum foil 4 is sandwiched between the pair of hot rolls heated at 180 ° C so as to overlap with the surface of the second adhesive layer 6 formed on the other surface of the aluminum foil 4 and heat laminated, Thereby obtaining a quadrilateral facer material 1 in plan view.

1 (A) was prepared by the method described in detail above by using the above-mentioned casing material 1. That is, the casing member 1 is folded in two at an intermediate position in the lengthwise direction inwardly between the casing member front face portion 21 and the outline member back face portion 22 in a substantially rectangular shape, And the facing surface portion 21 and the facing material backing portion 22 are connected to the positive electrode tab lead 11 and the negative electrode tab lead portion 21 at the opposite side edge portion 32 opposite to the two folded side edge portions 31, The negative electrode tab lead 12 is fitted and joined by the heat seal to form the opposing side portion 35. The one side adjacent first side portion 33 adjacent to the bending side 31 forms the facing surface front portion 21, And the second adjacent side edge portion 34 adjacent to the bent side edge 31 are connected to the front surface portion 21 of the covering material 21 (22) are formed as openings (24) that are opened without being actually bonded to each other. Thereby forming a seal member 30 (see Fig. 1 (A)). And the actual width of the opposite side portion 35 and the first adjacent side portion 36 was set to 5 mm.

Next, the temporary seal member 30 is disposed in a standing state with the first adjacent side flap portion 36 downward and the opening portion 24 upward, and the electrolyte injection nozzle 40 inserted from the top opening portion, The electrolyte solution was injected into the battery main body 23 (see Fig. 1 (B)). As the electrolytic solution, a solution (electrolytic solution) in which a lithium salt of hexafluoride was dissolved so as to have a concentration of 1 mol / l was used for a mixed solvent in which ethylene carbonate and diethylene carbonate were mixed at a volume ratio of 1: 1 (an injection step).

Next, an opening at the upper end of the gas chamber 41 in the temporary sealing member 30 was heat-sealed to form a gas-room upper end seal portion 37 to form a sealing bag (see Fig. 1 (C)). Then, the sealing pouch (temporary sealing member) 30 was placed in the chemical conversion treatment vessel 50 and a chemical conversion treatment was carried out to infiltrate the electrolyte into the electrode material (positive electrode material and negative electrode material) (Fig. 2 A)).

Next, while performing the deaeration (vacuum degassing) of the inside of the sealing bag (temporary sealing member) 30, the second adjacent edge 34 in the sealing bag (temporary sealing member) And the first seal part 27 was formed by heat seal bonding using a bar (first seal step). In this first batch process, the heat room conditions were 200 占 폚 for 0.2 MPa for 6 seconds. In the first heat seal bar, a fluororesin tape adhered to the surface of the metal seal bar was used.

After the first sealing step (after the completion of the degassing), the first sealing part 27 is again subjected to heating and pressing by using the second sealing seal bar to form a second adjacent side part (second sealing part) 27, Sealing with the exterior material was completed (second sealing step) (see Fig. 2 (B)). In this second batch process, the heat room conditions were 200 占 폚 占 0.2 MPa 占 6 seconds. On the second heat seal bar, a fluororesin tape adhered to the surface of the metal seal bar was used.

Next, a portion (generally upper half) corresponding to the gas chamber 41 in the sealing pouch 30 was removed by trimming to obtain a laminate battery 10 shown in Fig. 2 (C).

<Comparative Example 1>

Up to the conversion treatment step, a sealing bag (temporary sealing member) 30 shown in Fig. 2A was obtained in the same manner as in Example 1. Fig. Next, the second adjacent edge portion 34 of the sealing bag (temporary sealing member) 30 is removed by using the heat seal bar while performing the deaeration (vacuum degassing) of the inside of the sealing bag (temporary sealing member) And the second adjacent side surface portion 27 was formed by heat seal bonding. In this actual process, the heat room conditions were 200 占 폚 占 0.2 MPa 占 10 seconds. In the heat seal bar, a fluororesin tape adhered to the surface of the metal seal bar was used. Next, a portion corresponding to the gas chamber (roughly the upper half) in the sealing bag was removed by trimming to obtain a laminated battery.

Each laminated battery obtained as described above was evaluated based on the following evaluation method. The results are shown in Table 1.

<Actual Strength Evaluation Method>

A test piece (width 15 mm) was prepared from the second adjacent side portion 27 with respect to each laminated battery. Using this autograph of Shimazu Co., Ltd., the test piece was subjected to a tensile test at a tensile speed of 100 mm / Peel strength) was measured.

&Lt; Evaluation method of frequency of delamination (peeling) >

Ten laminate batteries of Example 1 were prepared, and ten laminate batteries of Comparative Example 1 were prepared. After each laminated battery was allowed to stand at room temperature for 7 days, the presence or absence of delamination (peeling) in the second adjacent side portion of each laminated battery was investigated. In each of Example 1 and Comparative Example 1, Table 1 shows the number of delamination-generating samples (cells) in the sample (cell).

As is apparent from Table 1, in the laminate battery of Example 1 produced by the production method of the present invention, the process time could be shortened and sufficient room strength was obtained, and no delamination occurred The frequency was 0/10).

On the other hand, in the laminate battery of Comparative Example 1, sufficient room strength was obtained and no delamination occurred (the frequency of occurrence of delamination was 0 pieces / 10 pieces), which required time for the actual process, have.

[Industrial Availability]

The method for producing a battery according to the present invention is suitable as a method for producing a laminate type secondary battery such as a laminate lithium ion secondary battery, but is not particularly limited to the application to such a use.

This application is a continuation-in-part of Japanese Patent Application No. 2014-263888, filed on December 26, 2014, which is incorporated herein by reference in its entirety.

The terms and explanations used here are used for explaining the embodiments of the present invention, and the present invention is not limited thereto. It is intended that the present invention not be limited by any of the details of the description provided herein except as defined in the appended claims.

1: Outer material 2: Heat-resistant resin layer (outer layer)
3: thermoplastic resin layer (inner layer) 4: metal foil layer
10: Battery 21: Facade front part
22: exterior material backing part 23: battery body part
24: opening portion 27: second adjacent side surface portion (plural times of the actual portion)
30: temporary seal member 31: bent side (bent portion)
32: opposing edge portion 33: first adjacent edge portion
34: second adjacent side 35: opposite side
36: first adjacent side bar portion 40: nozzle for injecting electrolyte
43: heat seal bar 44: contact face
46: heat seal bar 48: porous sheet

Claims (6)

A battery body portion is disposed in a substantially rectangular bag-shaped bag body formed of a casing material including a heat-resistant resin layer as an outer layer, a thermoplastic resin layer as an inner layer, and a metal foil layer disposed between both layers, Preparing a temporary seal member which is sealed by three of four sides near the periphery of the battery main body and the other one of which is opened by an opening,
The tip of the nozzle for injecting the electrolyte is disposed at a position directly above the opening or inserted into the opening to inject the electrolyte solution into the battery main body part, ,
A first sealing step of sealing the opening portion with a first heat seal bar to form a first seal portion while degassing the interior of the temporary seal member using a deaerator,
And a second sealing step of applying heat and pressure to the first seal part using a second heat seal bar after the deaeration is completed. The method according to claim 1,
The temperature of the first heat seal bar at the time of heat sealing in the first sealing step is set to a temperature equal to or higher than the melting point of the thermoplastic resin layer,
Wherein the temperature of the second heat seal bar at the time of heat sealing in the second sealing step is set at a temperature equal to or higher than the melting point of the thermoplastic resin layer. The method according to claim 1,
Wherein the thermoplastic resin layer of the temporary seal member has a multilayer structure including a low melting point thermoplastic resin layer disposed on the inner surface side and a high melting point thermoplastic resin layer disposed on the metal foil layer side,
The temperature of the first heat seal bar at the time of heat sealing in the first sealing step is set to a temperature equal to or higher than the melting point of the low melting point thermoplastic resin layer,
Wherein the temperature of the second heat seal bar at the time of heat sealing in the second sealing step is set to a temperature equal to or higher than the melting point of the low melting point thermoplastic resin layer. 4. The method according to any one of claims 1 to 3,
It is possible to use a pair of heat seal bars in which the inner contact surfaces are formed in a curved shape in which the central portion in the longitudinal direction and / or the width direction of the heat seal bar projects in the first and second sealing processes Wherein the method comprises the steps of: 4. The method according to any one of claims 1 to 3,
Wherein a pair of heat seal bars in which a porous sheet is disposed on an inner contact surface are used in the first sealing step and / or the second sealing step. 4. The method according to any one of claims 1 to 3,
Wherein one side of the three sealed sides of the temporary sealing member is sealed by the folded portion formed by folding the two inwardly with the inner layer inward.

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