JP5025277B2 - Battery manufacturing method - Google Patents

Description

  The present invention relates to a battery and a manufacturing method thereof.

  With the progress of electronic devices such as mobile phones and personal computers, secondary batteries used in these devices are constantly required to be reduced in cost as well as to be reduced in size, weight, thickness and capacity. As a flat secondary battery having a high energy density, a lithium ion secondary battery can be mentioned. The electrode material such as the positive electrode active material or the negative electrode active material is changed to one having a higher energy density, or the material for forming the container is iron. Improvements such as replacing aluminum with aluminum have been attempted.

  Recently, by using a container made of a laminated film in which a protective layer or a sealant layer (heat fusion layer) is formed on the surface of an aluminum sheet, non-aqueous electrolytes in various forms such as liquid, gel or solid have been used. In a flat type nonaqueous electrolyte battery, size reduction, weight reduction, and thickness reduction are achieved.

  In a flat type nonaqueous electrolyte battery, an electrode body in which a separator is interposed between a positive electrode and a negative electrode is used. The positive and negative terminals are respectively connected to the positive electrode and the negative electrode of the electrode body. For example, a liquid non-aqueous electrolyte is used, and the electrode body is impregnated. In order to seal the electrode body in the laminated film container, first, the electrode body is housed in the container, and the open part of the container is heated and pressurized with a heater fitting, and the sealant layers are heat-sealed. And seal. The positive and negative electrode terminals are drawn out from the open part of the container, and are sealed by heat sealing the sealant layer to the positive and negative terminals.

  Since the metal material of the positive and negative electrode terminals and the sealant layer of the container are usually inferior in adhesion and adhesiveness, they are integrated by heat fusion by interposing a heat-fusible film between the positive and negative electrode terminals and the sealant layer. In many cases, a sealing method is used.

  However, in the above-described sealing method, the thickness of the portion to be sealed varies. Specifically, the portion where the positive or negative electrode terminal, the sealant layer and the heat-fusible film overlap is the thickest, and then the portion where the sealant layer and the heat-fusible film overlap without any positive and negative electrode terminals, The thin part is the part where the sealant layers directly overlap.

  In order to heat-seal the three locations at the same time, if the amount of heat and pressure applied are not sufficient, they will not adhere to each other, and there will be no gap at the boundary where the thickness of the fused portion is different, or where the thickness of the fused portion is the smallest. Occurs and sealability decreases. If the amount of heat applied and the pressure are increased excessively in order to prevent the generation of gaps, the heat-fusible film for improving the adhesion of the peripheral portions of the positive and negative electrode terminals becomes extremely thin, and the sealing performance is lowered. In addition, the insulation distance between the metal sheet portion of the laminated film constituting the container and the positive and negative electrode terminals becomes extremely short, and impact and load are applied to the fused portion of the positive and negative electrode terminals, so that each terminal of the positive and negative electrodes is simultaneously metal sheet If it touches, it will fall into a short circuit state.

  Therefore, when heat-sealing portions having different thicknesses of the fusion part, as shown in Patent Document 1, a method is used in which a concave portion is provided on the surface of at least one heater fitting to absorb unevenness of the fusion part. ing.

  FIG. 12 is an explanatory diagram of a sealing method in which a recess is provided on the surface of a heater fitting as exemplified in Patent Document 1. A heat-fusible film 33 is disposed on both surfaces of the positive electrode terminal 31 and the negative electrode terminal 32. The laminated film 34 constituting the container is composed of a protective layer 35, an aluminum sheet 36 and a sealant layer 37. The recess 39 of the heater fitting 38 is provided at a position corresponding to the heat-fusible film 33.

  When sealing is performed continuously using the heater metal fittings illustrated in FIG. 12, heat sealing is performed while the welding temperature is lowered, and the vicinity of the portion where the thickness of the sealed portion changes A gap is generated between X and Y (shown in FIG. 13), and sealing performance is not ensured.

  Therefore, it is necessary to further increase the fusing temperature, lengthen the fusing time, or increase the fusing pressure, but these may lead to a decrease in production efficiency, deterioration of production equipment, periodic replacement, etc. You must also pay attention to the management.

Furthermore, the insulation distance between the metal sheet layer such as aluminum or aluminum alloy of the laminated film constituting the container and the positive electrode terminal or the negative electrode terminal is not stable, which increases the risk of a short circuit of the battery.
JP 2002-190283 A

  The present invention has been made based on these circumstances, and an object of the present invention is to provide a method of manufacturing a flat battery with improved sealing performance and a flat battery.

The flat battery according to the present invention has a film container in which a heat-sealed part in which film end parts are heat-sealed is formed on at least one side of the periphery;
A flat electrode body that is housed in the container and includes a positive electrode and a negative electrode;
A positive electrode terminal connected to the electrode body, the tip of which is drawn out through the thermal fusion part of the container;
A flat battery comprising a negative electrode terminal connected to the electrode body and having a tip drawn out through the thermal fusion part of the container,
A streak-like recess formed by pressurization is formed in a portion where the positive electrode terminal and the negative electrode terminal of the heat-sealed part are interposed, and the streak-like recess is formed with respect to a drawing direction of the positive electrode terminal and the negative electrode terminal. It is characterized by extending vertically.

In the flat battery manufacturing method according to the present invention, a flat electrode body including a positive electrode and a negative electrode is connected to a positive electrode terminal and a negative electrode terminal in a film container in which at least one side of the periphery is unheat-sealed. Storing and pulling out the positive electrode terminal and the negative electrode terminal from one side of the non-thermal fusion,
A pair of heater metal fittings having a streaky projection parallel to one side of the non-thermal fusion on the sealing surface, sandwiching one side of the non-thermal fusion, and thermally fusing one side of the non-thermal fusion by heating and pressing. And a step of attaching.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the flat type battery which improved the sealing performance, and the flat type battery by it can be provided.

  Embodiments according to the present invention will be described below with reference to FIGS. FIG. 1 is a perspective view showing a flat secondary battery manufactured by the method according to this embodiment.

  As shown in FIG. 1, the flat secondary battery includes a film container 1 and a flat electrode body 2 shown in FIG. The electrode body 2 is comprised from the positive electrode, the negative electrode, and the separator interposed between a positive electrode and a negative electrode (not shown). The electrode body is produced, for example, by winding the positive electrode and the negative electrode in a flat spiral shape via a separator, or alternately laminating the positive electrode and the negative electrode with a separator interposed therebetween. A non-aqueous electrolyte (not shown) is held by the electrode body 2. Examples of the non-aqueous electrolyte include a liquid non-aqueous electrolyte, a gel-like non-aqueous electrolyte, and a solid non-aqueous electrolyte. One end of the strip-like positive electrode terminal 3 is electrically connected to the positive electrode. One end of the strip-like negative electrode terminal 4 is electrically connected to the negative electrode. The positive electrode terminal 3 is made of, for example, aluminum or an aluminum alloy. On the other hand, the negative electrode terminal 4 is made of, for example, nickel or copper.

  A state before the container 1 is sealed is shown in FIG. The container 1 has a rectangular cup portion 5 in which the electrode body 2 is accommodated. Edge portions 5 a to 5 d are formed at the opening end of the cup portion 5. Of these, the edge 5d formed at one short side opening end is wide and functions as a sealing plate (hereinafter referred to as sealing plate 5d). The electrode body 2 is accommodated in the cup portion 5 of the container 1 such that the positive electrode terminal 3 and the negative electrode terminal 4 are pulled out from the edge portion 5a. The container 1 is folded in half so that the cup portion 5 is covered with the sealing plate 5d and the three sides of the sealing plate 5d are in contact with the edges 5a to 5c. The electrode body 2 is sealed in the container 1 by the sealing plate 5d and the edges 5a to 5c being bonded together by heat sealing.

  For example, as shown in FIG. 4, the film 6 constituting the container 1 includes a barrier layer 7 that prevents permeation of moisture and gas, a protective layer 8 formed on one surface of the barrier layer 7, and the other of the barrier layer 7. And a laminate film formed from the sealant layer 9 formed on the surface. The barrier layer 7 is preferably made of a metal having a small specific gravity such as aluminum or an aluminum alloy. The protective layer 8 is preferably a film having mechanical strength, and typically includes a polyethylene terephthalate (PET) film or a nylon film. The sealant layer 9 is preferably a film having heat fusion properties, and a polyolefin film (polypropylene, polyethylene, etc.) having excellent resistance to dissolution in an electrolyte or a contained solvent is used. The sealant layer 9 is located on the inner surface of the container 1, that is, the inner surface of the cup portion 5, the surfaces of the edges 5a to 5c, and the inner surface of the sealing plate 5d.

  Since the positive and negative terminals 3 and 4 are made of a metal material, the adhesion and adhesiveness with the sealant layer 9 of the container 1 are slightly inferior. Therefore, in order to increase the sealing strength, it is desirable to cover the portions of the positive and negative electrode terminals 3 and 4 facing the sealant layer 9 with the heat-fusible film 10. Examples of the heat-fusible film 10 include films of acid-modified polyolefins such as acid-modified polypropylene and acid-modified polyethylene. The heat-fusible film 10 having a single layer structure may be used, but not limited thereto, and a film having a multilayer structure may be used. In that case, if at least the resin layer in contact with the positive and negative electrode terminals is an acid-modified polyolefin film such as acid-modified polypropylene or acid-modified polyethylene having good adhesion to the metal, the other part of the heat-fusible film The structure of is not ask | required. Further, as shown in FIG. 2, the positive and negative terminals 3 and 4 may be individually covered with the heat-fusible film 10, but the positive and negative terminals 3 and 4 are straddled with a single heat-fusible film. It may be covered.

  A method for heat-sealing the sealing plate 5d and the edges 5a to 5c will be described below.

  A method for heat-sealing the sealing plate 5d and the edge portion 5a will be described with reference to FIGS. First, the positive and negative terminals 3 and 4 and the heat-fusible film 10 disposed between the sealing plate 5d and the edge 5a are positioned. Next, the nonaqueous electrolyte is accommodated in the cup portion 5.

  As shown in FIGS. 5 and 6, a recess 12 is formed on the seal surfaces of the pair of heater fittings 11 a and 11 b. The concave portion 12 is opposed to a portion where the sealing plate 5d, the positive electrode terminal 3, and the edge portion 5a overlap to a portion where the sealing plate 5d, the negative electrode terminal 4, and the edge portion 5a overlap. The depth of the recess 12 is made smaller than the sum of the thickness of the positive electrode terminal 3 or the negative electrode terminal 4 and the thickness of the heat-fusible film 10 formed on one surface of the positive electrode terminal 3 or the negative electrode terminal 4. In the concave portion 12, streaky convex portions 13 a and 13 b are formed in parallel with the short side of the container 1 (perpendicular to the pulling direction A of the positive and negative terminals 3 and 4). The positions of the protrusions 13a and 13b are not particularly limited as long as they overlap with the positions of the positive and negative terminals 3 and 4 interposed between the sealing plate 5d and the edge 5a. Further, the number of convex portions is not limited to two, and can be one or three or more.

  The height of the convex portions 13a and 13b is 30 of the total thickness of the members to be heat-sealed (the sum of the thickness of the positive electrode terminal 3 or the negative electrode terminal 4, the thickness of the container 1 and the thickness of the heat-fusible film 10). % Or more and 80% or less is desirable. Here, the thickness of the container 1 is the sum of the thickness of the sealing plate 5d and the thickness of the edge portion 5a. Moreover, since the heat-fusible film 10 is formed on both surfaces of the positive and negative electrode terminals 3 and 4, a value twice the thickness of the heat-fusible film 10 is used. By setting the height of the convex portions 13a and 13b to 30% or more of the total thickness of the members to be heat-sealed, leakage during high temperature storage can be prevented. The higher the convex portions 13a and 13b, the greater the effect of preventing leakage. However, when the height of the convex portions 13a and 13b exceeds 80% of the total thickness of the members to be heat-sealed, the convex portion 13a. The height of the convex portions 13a and 13b is 30% or more of the total thickness of the members to be heat-sealed because there is a risk that only the portion pressurized by 13b is heat-sealed and the sealing performance is lowered. It is desirable to make it 80% or less.

  The portion where the sealing plate 5d and the edge portion 5a overlap is arranged on the lower heater metal fitting 11b, the upper heater metal fitting 11a is lowered, and the portion where the sealing plate 5d and the edge portion 5a overlap is heated the heater metal fitting 11a. 11b, and when heat and pressure are applied, the sealant layer 9 of the sealing plate 5d and the sealant layer 9 of the edge 5a are thermally fused on the flat sealing surfaces located on both sides of the recess 12 of the heater metal parts 11a and 11b. Worn. On the other hand, at the place where the heater metal fittings 11a and 11b are heated and pressed by the concave portion 12, the depth of the concave portion 12 is smaller than the sum of the thickness of the positive electrode terminal 3 or the negative electrode terminal 4 and the thickness of the heat-fusible film 10, And since the convex parts 13a and 13b are formed, the molten heat-fusible film 10 is crushed and a part protrudes outside the part currently pressed with the heater metal fittings 11a and 11b (FIG. 7, FIG. 8). Thereby, the heat-fusible film 10 is filled evenly in the gaps between the sealing plate 5d, the edge 5a, and the positive and negative terminals 3 and 4.

  Further, since a streak-like concave portion 14 is formed along the direction perpendicular to the pulling direction A of the positive and negative electrode terminals 3 and 4 at the locations pressurized by the convex portions 13a and 13b, the sealing plate 5d and the positive and negative electrode ends The joint strength between the child 3 and 4 and the edge 5a can be further increased. The heating temperature of the heater fittings 11a and 11b can be 160 ° C. or more and 200 ° C. or less. The applied pressure can be 0.1 MPa or more and 0.5 MPa or more, and the required time is about 5 seconds.

  The other edge portions 5b and 5c and the sealing plate 5d are heat-sealed by using the sealant layer 9 located on the inner surfaces thereof, so that the sealing performance is high even if there are portions having different thicknesses in the heat seal portion. It is possible to provide a safe flat secondary battery that does not cause leakage even during high-temperature storage. The order in which the edge portions 5a, 5b, and 5c are heat-sealed to the sealing plate 5d is not particularly limited, and any edge portion can be heat-sealed to the sealing plate 5d first. Then, all the edges may be heat-sealed to the sealing plate 5d at the same time.

  Hereinafter, a positive electrode, a negative electrode, a separator, and a nonaqueous electrolyte used for the secondary battery will be described.

As the positive electrode active material contained in the positive electrode, various oxides such as manganese dioxide, lithium manganese composite oxide (for example, LiMn ₂ O ₄ , LiMnO ₂ ), lithium-containing nickel oxide, lithium-containing cobalt oxide (for example, LiCoO ₂ ), lithium-containing nickel cobalt oxide (for example, LiNi _0.8 Co _0.2 O ₂ ), lithium-containing iron oxide, vanadium oxide containing lithium, chalcogen compounds such as titanium disulfide and molybdenum disulfide Can do. In addition, the kind of positive electrode active material to be used can be made into 1 type or 2 types or more.

  As the positive electrode current collector carrying the positive electrode active material, a conductive substrate having a porous structure or a nonporous conductive substrate can be used. These conductive substrates can be formed from, for example, aluminum, stainless steel, or nickel.

  As the negative electrode active material included in the negative electrode, lithium ions or a material that absorbs and releases lithium can be used. For example, a graphite material or a carbonaceous material (for example, graphite, coke, carbon fiber, spherical carbon, thermal decomposition) Gas phase carbonaceous material, resin fired body, etc.), chalcogen compound (eg, titanium disulfide, molybdenum disulfide, niobium selenide, etc.), light metal (eg, aluminum, aluminum alloy, magnesium alloy, lithium, lithium alloy, etc.), lithium Examples thereof include titanium oxide (for example, spinel type lithium titanate).

  As the negative electrode current collector carrying the negative electrode active material, a conductive substrate having a porous structure or a non-porous conductive substrate can be used. These conductive substrates can be formed from, for example, copper, aluminum, stainless steel, or nickel.

  As the separator, a microporous film, a woven fabric, a non-woven fabric, a laminate of the same material or different materials among these can be used. Examples of the material for forming the separator include polyethylene, polypropylene, ethylene-propylene copolymer, and ethylene-butene copolymer. As a material for forming the separator, one type or two or more types selected from the types described above can be used.

  The non-aqueous electrolyte includes a non-aqueous solvent and an electrolyte (for example, lithium salt) dissolved in the non-aqueous solvent. The form of this non-aqueous electrolyte can be liquid (non-aqueous electrolyte), gel or solid.

  Examples of the non-aqueous solvent include ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), γ-butyrolactone (γ -BL), sulfolane, acetonitrile, 1,2-dimethoxyethane, 1,3-dimethoxypropane, dimethyl ether, tetrahydrofuran (THF), 2-methyltetrahydrofuran and the like. Nonaqueous solvents may be used alone or in combination of two or more.

Examples of the electrolyte include lithium perchlorate (LiClO ₄ ), lithium hexafluorophosphate (LiPF ₆ ), lithium tetrafluoroborate (LiBF ₄ ), lithium hexafluoroarsenide (LiAsF ₆ ), and trifluoromethanesulfone. Examples thereof include lithium salts such as lithium acid lithium (LiCF ₃ SO ₃ ). The electrolyte may be used alone or in combination of two or more. The amount of electrolyte dissolved in the non-aqueous solvent is desirably 0.2 mol / L to 3 mol / L.

[Example]
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings described above.

Example 1
A nylon protective layer 8 having a thickness of 25 μm is laminated on one surface of a barrier layer 7 made of an aluminum sheet having a thickness of 40 μm, and a polyethylene sealant layer 9 having a thickness of 30 μm (melting point 120) on the other surface of the barrier layer 7. A rectangular cup portion 5 was formed by deep drawing on a laminate film 6 having a thickness of 95 μm laminated with a temperature of about 0 ° C. to obtain a container 1.

  The flat electrode body 2 shown in FIG. 2 was prepared. For the positive electrode terminal 3, an aluminum foil having a thickness of 200 μm was used. For the negative electrode terminal 4, a copper foil having a thickness of 200 μm was used. The heat-fusible film 10 was an acid-modified polyethylene film having a thickness of 200 μm.

The electrode body 2 is accommodated in the cup part 5 of the container 1 obtained, the container 1 is folded in two to cover the cup part 5 with the sealing plate 5d, and the positive and negative terminals 3 and 4 are connected to the edge part 5a and the sealing plate. It was pulled out from between 5d. As a non-aqueous electrolyte, LiPF ₆ was dissolved in a non-aqueous solvent in which ethylene carbonate (EC) and dimethyl carbonate (DMC) were mixed at a volume ratio of 1: 1 so as to have a concentration of 1 mol / L as an electrolyte. A non-aqueous electrolyte was prepared. This nonaqueous electrolytic solution was injected into the cup portion 5 of the container 1.

  The depth of the concave portion 12 on the seal surface of the pair of heater fittings 11a and 11b was set to 0.16 mm, and the height of the convex portions 13a and 13b was set to 0.16 mm. The total thickness of the members to be heat-sealed (the thickness of the positive electrode terminal 3 or the negative electrode terminal 4, the value twice the thickness of the laminate film 6 and the value twice the thickness of the heat-fusible film 10) ) Is 0.79 mm, the ratio of the height of the protrusions 13a and 13b to the total thickness of the members to be heat-sealed was 20%.

  By using the heater fittings 11a and 11b, the edge portion 5a and the sealing plate 5d were heat-sealed by the method shown in FIGS. Moreover, the edge parts 5b and 5c and the sealing board 5d were heat-seal | fused with the heater metal fitting with the flat sealing surface in which the recessed part was not formed. The heating temperature of the heater metal fitting was set to 195 ° C., and the applied pressure was set to 0.2 MPa. The time required for heat-sealing each of the edges 5a to 5c was about 5 seconds.

  A flat type nonaqueous electrolyte secondary battery was manufactured by the above method.

(Examples 2 to 5)
The flat type is the same as that described in Example 1 except that the ratio of the height of the convex portions 13a and 13b to the total thickness of the members to be heat-sealed is changed as shown in Table 1 below. A non-aqueous electrolyte secondary battery was manufactured.

(Comparative example)
A flat type nonaqueous electrolyte secondary battery was manufactured in the same manner as described in Example 1 except that the method of heat-sealing the edge 5a and the sealing plate 5d was changed. The heat fusion method will be described below.

  As shown in FIGS. 9 and 10, heater metal fittings 21 a and 21 b not provided with convex portions were prepared. The depth of the recess 22 formed in the heater fittings 21a and 21b was the same as in Example 1.

  The edge 5a and the sealing plate 5d were thermally fused by the method shown in FIGS. 9 to 11 using the heater fittings 21a and 21b. As shown in FIG. 11, although the heat-fusible film 10 protrudes outside the portion pressed by the heater fittings 21a and 21b, no streak-like convex portion was formed. In addition, the heating temperature of the heater metal fitting, the applied pressure, and the heat fusion time were the same as those in Example 1.

  With respect to the obtained secondary battery, the number of leaks (the number of parameters was 10) was measured when stored for 800 days in an environment where the temperature was 60 ° C. and the relative humidity was 93%, and the results are shown in Table 1 below. Show.

  As is apparent from Table 1, the secondary batteries of Examples 1 to 5 manufactured using the heater metal fittings having the convex portions formed on the seal surface are comparative examples in which the convex portions are not formed on the seal surface of the heater metal fittings. It can be seen that the number of leaks after storage for 800 days is smaller than that of the secondary battery. In particular, in the secondary batteries of Examples 2 to 4 in which the height of the convex portion is set to 30% or more and 80% or less, there is no number of leaks after storage for 800 days, and in order to obtain high sealing performance It is desirable that the height of the convex portion is 30% or more and 80% or less.

  According to the present invention, a method for manufacturing a flat secondary battery having excellent sealing performance, safety, and productivity, in which an electrode body is sealed inside a sealed body formed of an exterior material of a laminated film of aluminum or an alloy thereof. Thus, a flat secondary battery can be obtained.

  In the above-described embodiments, a battery using a nonaqueous electrolytic solution has been described as an example. However, a battery using a solid electrolyte or a polymer electrolyte instead of the electrolytic solution is naturally applicable. Furthermore, the positive and negative electrode active materials are not limited to this, and other active materials can be used. Further, in the embodiment, the heat fusion part is formed on the three sides of the container, but it is also possible to form the heat fusion part on all four sides of the container.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

The perspective view which shows the flat type non-aqueous electrolyte secondary battery concerning embodiment of this invention. The perspective view which shows the electrode group used for the flat type nonaqueous electrolyte secondary battery of FIG. The perspective view which shows the container used for the flat type nonaqueous electrolyte secondary battery of FIG. Sectional drawing of the laminate film which comprises the container of FIG. The perspective view for demonstrating the sealing process of the flat type nonaqueous electrolyte secondary battery of FIG. Sectional drawing obtained when the heater metal fitting used at the sealing process shown in FIG. 5 is cut | disconnected in the short side direction. Sectional drawing obtained when the flat type non-aqueous electrolyte secondary battery in a sealing process is cut | disconnected along the extraction direction of a positive / negative electrode terminal. Sectional drawing which expanded the principal part of FIG. The perspective view for demonstrating the sealing process of the flat type nonaqueous electrolyte secondary battery of a comparative example. Sectional drawing obtained when the heater metal fitting used at the sealing process shown in FIG. 9 is cut | disconnected in the short side direction. Sectional drawing obtained when the flat type non-aqueous electrolyte secondary battery in a sealing process is cut | disconnected along the extraction direction of a positive / negative electrode terminal. Sectional drawing for demonstrating the conventional sealing process of a flat type nonaqueous electrolyte battery. Sectional drawing which shows the flat type nonaqueous electrolyte battery manufactured through the conventional sealing process.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Container, 2 ... Electrode body, 3 ... Positive electrode terminal, 4 ... Negative electrode terminal, 5 ... Cup part, 5a-5c ... Edge, 5d ... Sealing plate, 6 ... Laminate film, 7 ... Metal layer, 8 ... Protective layer , 9 ... Sealant layer, 10 ... Heat-sealable film, 11a, 11b ... Heater fitting, 12 ... Recess, 13a, 13b ... Streaky convex, 14 ... Streaky recess, 21a, 21b ... Heater fitting, 22 ... Recess .

Claims (4)

A flat electrode body including a positive electrode and a negative electrode, to which a positive electrode terminal and a negative electrode terminal are connected, is housed in a film container having at least one peripheral edge unheat-sealed, and the positive electrode terminal and the negative electrode terminal are A process of drawing out from one side of the non-heat fusion,
The seal surface has a concave portion facing from the portion where one side of the non-thermal fusion and the positive electrode terminal overlaps to the portion where the one side of the non-thermal fusion and the negative electrode terminal overlaps, A pair of heater fittings having streak-like convex portions parallel to one side of the wear at both ends of the recess, sandwiching one side of the non-thermal fusion, and thermally fusing one side of the non-heat fusion by heating and pressing And a process for producing a flat battery. The positive terminal and the negative terminal, the manufacturing method of the flat-type battery according to claim 1, wherein the portion facing the one side of the non-heat-sealed is coated with the heat-welding film. Method for manufacturing a flat battery of the depth of the pre-Symbol recess claim 1 or 2, wherein the smaller than the sum of the thickness of the thickness of the positive electrode terminal or the negative terminal the heat-fusible film. The height of the convex portion of the pair of heater metal fittings corresponds to 30 to 80% of the sum of the thickness of the positive electrode terminal or the negative electrode terminal, the thickness of the container, and the thickness of the heat-fusible film. The method for manufacturing a flat battery according to any one of claims 1 to 3 .

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