JPH0878025A - Manufacture of stacked cell - Google Patents

Abstract

PURPOSE: To provide a stacked cell with less internal resistance and no deformation of a cell element during production by stacking thin cells, in which the periphery of a current collector is bonded with a heat adhesive resin frame, and heat-bonding the protruded part of the frame under reduced pressure. CONSTITUTION: A positive electrode active material 3, a solid electrolyte 4, and a negative electrode active material 5 are arranged between a positive current collector 1 and a negative current collector 2, and the peripheries of the current collectors 1, 2 are bonded with heat adhesive resin frame 6 each other. A plurality of thin cells in which the frame 6 is protruded to the outside of the current collectors 1, 2 are stacked. The protruded parts 6a of the frame 6 are heat-bonded under reduced pressure less than atmospheric pressure. In stead of heat-bonding under reduced pressure, a conductive material is placed between the stacked thin cells and heat-bonding of the thin cells is also allowable. Existing of air between the thin cells is prevented, and contact of the positive current collector 1 and the negative current collector 2 is increased. Internal resistance of the stacked cell is decreased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated battery obtained by laminating a plurality of thin batteries used in the fields of electronic equipment, electric vehicles, toys, accessories, display devices, emergency power supplies, portable equipment and the like. The present invention relates to a manufacturing method.

[0002]

2. Description of the Related Art A thin battery, as shown in FIG. 7, includes a positive electrode active material 3, a solid electrolyte 4, and a negative electrode active material 5 between a positive electrode current collector 1 and a negative electrode current collector 2 which also serve as an outer package. Along with
The peripheral edge portions of the current collectors 1 and 2 were adhered to each other with a thermo-adhesive resin frame body 6, and the frame body 6 was projected outside the peripheral edge portion. The manufacturing method of this battery is as follows:
The battery element and the frame body 6 between the negative electrode current collector 2 and the
Outside of the current collectors 1 and 2 in contact with the frame body 6 (vertical direction in FIG. 7)
It was a method of applying a hot plate to seal the inside of the battery. Therefore, the peripheral edge portions of the current collectors 1 and 2 in contact with the frame body 6 are recessed inward as compared with the central portion, and the peripheral edge thickness h ′ is smaller than the central cell thickness h. . A laminated battery in which a plurality of such thin batteries are laminated to increase the battery voltage has been conventionally manufactured as follows. That is, as shown in FIG. 8, a stack of thin batteries 7 and 7'is set in a mold 8, and the frame 8 is pressed from above and below the peripheral edge of the stack by the mold 8 to protrude from the peripheral edge. 6a was heat-welded to each other. In addition,
Reference numeral 9 in FIG. 8 is a sponge having elasticity that pressurizes the current collectors 1 and 2 so that they come into close contact with each other.

[0003]

The laminated battery produced by the method described in the prior art is composed of adjacent thin batteries 7,
The contact parts of the current collectors 1 and 2 of 7'cannot be completely integrated,
The internal resistance of the laminated battery was increased. Therefore, there is a problem that the power loss increases especially at the high rate discharge. Further, as described in the related art, the central portion of the thin battery is thicker than the peripheral portion, but this difference (h-
When h ') is 0.6 mm or more, a large bending stress is applied to the peripheral portions of the current collectors 1 and 2 when manufacturing a laminated battery,
The current collectors 1 and 2 are deformed, the battery element inside the battery is also deformed, and an internal short circuit occurs. The present invention has been made in view of the above problems, and an object of the present invention is to provide a method of manufacturing a laminated battery that has a low internal resistance and does not deform a battery element during manufacturing.

[0004]

In order to reduce the internal resistance among the above objects, the present invention provides a positive electrode active material 3 and a solid material between a positive electrode current collector 1 and a negative electrode current collector 2 which also serve as an outer package. Electrolyte 4
And a negative electrode active material 5, the peripheral portions of the current collectors 1 and 2 are adhered to each other with a thermo-adhesive resin frame 6, and the thin battery 7 with the frame 6 protruding outside the peripheral portion, It is characterized in that a plurality of 7'are laminated, and then the protruding portions 6a of the frame body 6 are heat-welded to each other under reduced pressure of less than atmospheric pressure. Also,
Instead of heat welding under reduced pressure below atmospheric pressure, a conductive material may be placed between the thin batteries 7 and 7 ′ to heat weld the thin batteries together, or they may be performed simultaneously. Further, among the above purposes, in order to prevent the deformation of the battery element during manufacturing,
According to the present invention, after stacking a plurality of thin batteries 7 and 7'where the frame 6 protrudes, a thermo-adhesive resin 6b is inserted into the gap 10 between the protruding portions 6a of the thin batteries 7 and 7 '. The protruding portions 6a of the frame body 6 are heat-welded to each other via the resin 6b.

[0005]

According to the first aspect, air is not present between the thin batteries, and the contact degree between the positive electrode current collector 1 and the negative electrode current collector 2 is increased. Therefore, the internal resistance of the laminated battery is reduced. According to claim 2, the conductive performance between the thin batteries is increased, and the internal resistance is reduced. According to the third aspect, since the gap 10 in the peripheral portion between the thin batteries is filled with the resin 6b, the current collectors 1 and 2 do not deform even when pressure is applied from the vertical direction of the peripheral portion.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 is a perspective view of a main part of a current collector plate 11 in which a positive electrode current collector 1 or a negative electrode current collector 2 according to the present invention is arranged in a strip shape, and the current collector 1 is cut into a predetermined size. Or it becomes 2.
In addition, 11a is a hole for alignment, 11b is a division hole of a pattern, and 11c is a connection part of a division hole. This current collector 11
In order to extend the battery life, the current collector 1 or 2 needs to be non-porous, and the thickness thereof needs to be about 0.010 mm or more for stainless foil and about 0.020 mm or more for copper foil. In order to improve the adhesiveness to the positive electrode active material 3 and the bending characteristics, the carbon-based resin is applied and cured in each pattern area of the current collector 11 which becomes the positive electrode current collector 1. Surface treatment. Then, manganese oxide, nickel oxide, cobalt oxide, vanadium oxide, or disulfide, which is doped with or without lithium, is used as a conductive material such as carbon, graphite, acetylene black, or Ketjen black, an electrolyte, a monomer. − About 0.15 of the positive electrode active material 3 kneaded with
It is printed with a thickness of mm to 0.20 mm and cured by electron beam irradiation (or heat, UV, etc.).

On the other hand, a negative electrode active material 5 such as metallic lithium, lithium-aluminum alloy, carbon or the like is pressure-bonded or printed in each pattern area serving as the negative electrode current collector 2. Further, a solid electrolyte 4 (electrolyte, monomer, filler, etc.) covering the entire surface of the negative electrode active material 5 is about 0.020 mm-
Printed to a thickness of 0.055mm and irradiated with electron beam (or heat V
Etc.) to cure. Next, the inner size is about 0.2 to 0.5 mm larger than the outer size of each of the active materials 3 and 5 and the outer size of the current collector (corresponding to the length between the insides of the patterned holes). The plate 12 of the series of thermo-adhesive resin frames 6 shown in FIG. 2 which is made larger and patterned is press punched or engraved blade rolls,
The holes 12a are formed at regular intervals using a Thomson blade or the like. The plate 12 of the frame body 6 is made of, for example, polypropylene or modified polypropylene and has a thickness of about 0.2.
It is set to 0 mm to 0.30 mm.

Next, the plate 12 of the heat-adhesive resin frame 6 is placed on the current collector plate 11 on which the negative electrode current collector 2 is patterned, and the holes 11a and 12a are aligned with each other to form the current collector 2. The patterns of the frame body 6 were matched. Then, the current collector plate 11 of the positive electrode current collector 1 was placed thereon, the holes 11a and 12a were aligned, and the patterns of the current collector 1 and the frame 6 were aligned. Next, a heat plate is pressed from the outside of the current collector plate 11 in the portion where the plate 12 of the frame 6 is arranged, the plate 12 and the current collector plate 11 are heat-welded, and arranged in a strip shape as shown in FIG. A number of thin batteries were manufactured. Next, the connecting portion 11c of the current collector plate 11 was trimmed with a laser or the like to electrically separate adjacent thin batteries. After that, the plate 12 of the frame body was cut along the partition holes 11b to produce a large number of thin batteries. In addition, the width dimension of the partition hole 11a is set to 0.4 mm or more so that the frame body 6 protrudes from the periphery of the current collector 1 or 2 by 0.2 mm or more, and the central portion of the partition hole 11a is an engraving blade roll, a Thomson blade, or the like. I cut it.

Next, as shown in FIG. 4, two thin batteries 7 and 7'are stacked in a decompression device, and a frame 8 is extruded by a mold 8 shown in the prior art in a state under atmospheric pressure. The portion 6a was pressure-heat-welded to prepare a laminated battery A as shown in FIG. The internal resistance of this battery A was compared with that of a conventional battery (a battery manufactured in the same manner as this example except that it was manufactured in the atmosphere). As a result, the present battery A was about 1.5 ohms less than the conventional battery.

(Embodiment 2) In the above embodiment, when the thin type batteries 7 and 7'are stacked, a conductive material is applied onto the collectors 1 or 2 in contact with the batteries, as shown in FIG. A laminated body was produced. Then, the protruding portions 6a of the frame body 6 were pressed and heat-welded together by the mold 8 to fabricate a laminated battery B as shown in FIG. When the internal resistances of this battery B and the battery A of Example 1 were compared, this battery B was about 1.2 ohms less. Note that the current collectors 1 and 2 may be plated with nickel in order to further reduce the contact resistance.

(Embodiment 3) FIG. 6 is a cross-sectional view of a laminated battery manufactured according to still another embodiment, and the same reference numerals as those in Embodiment 1 indicate the same names. Such a battery is manufactured by stacking two thin batteries 7 and 7 ′ manufactured in the same manner as in Example 1 as shown in FIG.
The adhesive resin 6b was inserted into the gap 10 of FIG. Next, the die 8 is pressed from above and below to heat-weld the protruding portion 6a of the upper battery 7, the resin 6b, and the protruding portion 6a of the lower battery 7'to produce a laminated battery C. did. A laminated battery manufactured by the method of Example 3 and the conventional method using the thin battery of FIG. 7 in which the difference between the thickness h ′ of the central portion and the thickness h ′ of the peripheral portion is 0.8 mm. 1 for C and D
When 0 pieces were manufactured and it was investigated whether or not there was an internal short circuit, it was found that there were none in the battery C, but there were 3 pieces in the battery D.

[0012]

As described above, the laminated battery of the present invention has the following effects. (1) According to claims 1 and 2, the internal resistance can be reduced, and a laminated battery excellent in high rate discharge characteristics can be provided. (2) According to claim 3, the current collector and the battery element can be prevented from being deformed, and a laminated battery without internal short circuit can be manufactured.

[Brief description of drawings]

FIG. 1 is a perspective view of an essential part showing a strip-shaped current collector plate according to the present invention.

FIG. 2 is a perspective view of an essential part showing a plate of a band-shaped heat-adhesive resin frame body according to the present invention.

FIG. 3 is a cross-sectional view of an essential part showing a thin battery arranged in a strip according to the present invention.

FIG. 4 is a cross-sectional view showing a state in which two thin batteries according to the present invention are stacked.

FIG. 5 is a cross-sectional view showing a laminated battery manufactured according to Examples 1 and 2 of the present invention.

FIG. 6 is a cross-sectional view showing a laminated battery produced according to Example 3 of the present invention.

FIG. 7 is a cross-sectional view showing a thin battery according to the related art or the present invention.

FIG. 8 is an explanatory view showing a method of manufacturing a laminated battery according to the related art or the present invention.

[Explanation of symbols]

 1 Positive Electrode Current Collector 2 Negative Electrode Current Collector 3 Positive Electrode Active Material 4 Solid Electrolyte 5 Negative Electrode Active Material 6 Thermal Adhesive Resin Frame 6a Overhanging Part of Frame 6b Resin 7,7 'Thin Battery 10 Gap

Claims (3)

[Claims] 1. A positive electrode active material (3), a solid electrolyte (4) and a negative electrode active material (5) are arranged between a positive electrode current collector (1) also serving as an outer package and a negative electrode current collector (2). , The current collector (1,
The peripheral edges of 2) are adhered to each other with a thermo-adhesive resin frame (6), and a plurality of thin batteries (7, 7 ') protruding from the frame (6) are stacked outside the peripheral edge, Next, a method for manufacturing a laminated battery, characterized in that the protruding portions (6a) of the frame body (6) are heat-welded to each other under reduced pressure below atmospheric pressure. 2. A positive electrode active material (3), a solid electrolyte (4) and a negative electrode active material (5) are arranged between a positive electrode current collector (1) also serving as an outer package and a negative electrode current collector (2). , The current collector (1,
A plurality of thin type batteries (7, 7 ') are prepared by adhering the peripheral portions of 2) to each other with a thermo-adhesive resin frame (6) and protruding the frame (6) outside the peripheral portions, Then, a conductive material is placed on the current collector (1 or 2) of the thin battery (7), and the thin battery (7 ') is laminated on the conductive material to form the frame (6). A method for manufacturing a laminated battery, characterized in that the protruding portions (6a) are heat-welded to each other. 3. A positive electrode active material (3), a solid electrolyte (4) and a negative electrode active material (5) are arranged between a positive electrode current collector (1) also serving as an outer package and a negative electrode current collector (2). , The current collector (1,
The peripheral edges of 2) are adhered to each other with a thermo-adhesive resin frame (6), and a plurality of thin batteries (7, 7 ') protruding from the frame (6) are stacked outside the peripheral edge, Then, the protruding portion (6) of the thin battery (7, 7 ')
A heat-adhesive resin (6b) is inserted into the gap (10) between a), and the protruding portions (6a) of the frame body (6) are heat-welded to each other via the resin (6b). Battery manufacturing method.