JP2013206587A - Method for manufacturing battery with flat electrode body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain thickness of a battery from increasing due to charging/discharging of a battery having a flat electrode body.SOLUTION: A method for manufacturing a battery having a flat electrode body comprises: an electrode body manufacturing step of manufacturing an electrode body by laminating or winding a positive electrode plate to which a positive electrode tab is mounted, and a negative electrode plate to which a negative electrode tab is mounted, via a separator; and a hot-press step of pressing the electrode body using to heated pressurizing jigs into a flat electrode body with thickness of 4 mm or less. A recess is provided on a face of at least one of the pressurizing jigs opposite to the electrode body in a region overlaid on the positive electrode tab and the negative electrode tab.

Description

  The present invention relates to a method for manufacturing a battery including a flat electrode body, and more particularly to a method for manufacturing a flat electrode body.

  In recent years, mobile information terminals such as mobile phones, notebook computers, and PDAs have been rapidly reduced in size, weight, and functionality, and secondary batteries as drive power sources can be easily mounted inside mobile information terminals. In addition, it is required to easily extract a large current.

  A battery that accommodates a flat electrode body that is formed by winding or laminating a positive and negative electrode plate and a separator interposed between the positive and negative electrode plates in a rectangular outer can or laminate outer package, Since it is large, it is easy to take out a large current, and it is easy to mount in the mobile information terminal, so that it is useful as a driving power source for the mobile information terminal.

  Such a flat electrode body is produced by stacking positive and negative electrodes and a separator, winding or laminating them, and then pressing. Recently, there is an increasing demand for downsizing of batteries, and pressing at a high pressure and pressing at a temperature higher than room temperature (25 ° C.) are performed.

  Here, Patent Documents 1 to 3 are proposed as techniques for producing a flat electrode body by pressing.

JP 2010-198987 Patent No. 3005493 Japanese Patent Laid-Open No. 2002-246069

  The technique of patent document 1 is a pressure heating molding machine provided with a heater unit for an electrode group obtained by laminating, or laminating and winding a first electrode sheet, a second electrode sheet, and a separator. It is a technique of using and pressurizing under heating. According to this technique, an increase in the gap between the electrode group constituent members during operation and the deformation of the electrode group can be suppressed, and performance deterioration and safety reduction can be further prevented.

  In the technique of Patent Document 2, an electrode group in which a sheet-like positive electrode, a sheet-like negative electrode, and a porous plastic sheet disposed between these electrodes are insulated and laminated in a flat shape is inserted into a can case. It is a technique of performing high temperature compression molding at 60 to 120 ° C. before. According to this technology, it is possible to provide an electrode group that has no winding looseness, has no space in the center of the electrode group after insertion into the battery can case, and further has no gap between the positive electrode sheet and the plastic sheet and between the negative electrode sheet and the plastic sheet. Is done.

  The technique of Patent Document 3 is an electrode that is heated at a constant temperature for a certain period of time between the pressing surface of the upper mold and the bottom of the molding recess of the mold, and is pressed at a constant pressure to be molded into a flat shape. This is a technique for obtaining a laminate. According to this technology, the manufacturing time can be shortened and the manufacturing cost can be reduced.

  When the present inventors diligently studied about a method of manufacturing a flat electrode body by pressing, a positive electrode plate attached with an electrode tab that is connected to an external terminal, or a part of which protrudes outside the battery and functions as an external terminal, It was found that when a flat electrode body having a small thickness was produced using the negative electrode plate, the thickness of the electrode body was greatly increased by charging / discharging, and the battery thickness was thereby greatly increased.

  The present invention has been completed by further study of the above problems by the present inventors, and an object of the present invention is to provide a pressing method that does not cause swelling of the flat electrode body due to charge and discharge.

  The present invention for solving the above-mentioned problems is an electrode body production process for producing an electrode body by laminating or winding a positive electrode plate to which a positive electrode tab is attached and a negative electrode plate to which a negative electrode tab is attached via a separator. And a hot pressing step of heating and pressing the electrode body using two pressure jigs to form a flat electrode body having a thickness of 4 mm or less, and at least one of the electrode bodies of the pressure jig Is a manufacturing method of a battery provided with a flat electrode body in which a concave portion is provided in a region overlapping with the positive electrode tab and the negative electrode tab.

  In order to compress the electrode body strongly, it is preferable to heat (press) the pressure jig at a temperature higher than room temperature (25 ° C.). Here, when a hot press is performed using a jig that does not have a recess in the region overlapping the positive electrode tab and the negative electrode tab (in the form of a flat plate), the thickness of the tab portion in the electrode body is thicker than the other portions. It will be pressed strongly and weakly pressed in other parts. For this reason, in the part hot-pressed strongly, the hole of a separator is crushed and the air permeability of a separator becomes large. As a result, the lithium ion permeability is deteriorated and lithium is liable to precipitate on the electrode, which causes the battery to swell. Further, in the weakly pressed portion, the press is loosened due to the volume fluctuation of the electrode plate due to charge / discharge, and the battery is further swollen. This problem occurs remarkably when the thickness of the produced flat electrode body is 4 mm or less.

  In the present invention, since the concave portion is provided in the region overlapping with the positive electrode tab and the negative electrode tab, a strong pressing pressure is not applied to the tab portion, and the entire portion is pressed uniformly, so that press imbalance does not occur. Therefore, the above problem does not occur and battery swelling is suppressed.

  The hot pressing step may be a method of pressing the electrode body in a state where the pressure jig is preheated, or a method of heating the pressure jig in a state where the electrode body is pressed by the pressure jig. However, the former is preferable from the viewpoint of productivity and the like.

  In addition, the heating method of a pressurization jig | tool is not specifically limited, A well-known method is employable.

  The said recessed part can be provided separately, respectively, when the positive electrode tab and the negative electrode tab are not adjoining. In this case, the size of the concave portion only needs to be larger than the overlapping tabs, and when the positive electrode tab and the negative electrode tab are different in size, it is not necessary to provide two concave portions larger than both the positive electrode tab and the negative electrode tab. In addition, when the positive electrode tab and the negative electrode tab are close to each other (for example, the distance between the two is 5 mm or less), one concave portion is provided in a region overlapping the positive electrode tab, the negative electrode tab, and the area between the two. Can do. Moreover, it is preferable that the positive electrode tab and the negative electrode tab do not overlap each other.

  Moreover, although the said recessed part can be set as the structure provided only in one of two pressurization jigs, More preferably, it provides in both.

  By the way, an insulating member layer may be provided on the positive electrode tab or the negative electrode tab so as to cover the tab in order to prevent the tab from breaking through the separator and the like. In this case, it is preferable that the concave portion of the pressure jig is formed in a region overlapping with the insulating member layer (larger than the size of the insulating member layer). As the insulating member layer, an insulating tape provided with an adhesive layer on one surface of a thin plate-like insulating sheet, or an insulating layer provided with insulating inorganic particles and an insulating binder can be used. In addition, the insulating member layer may be provided only on the tab, or may be provided so as to cover the tab and the electrode plate portion in the vicinity of the tab. Is preferred.

  The electrode body manufactured in the electrode body manufacturing step is preferably a wound electrode body because it is easy to manufacture. The wound electrode body may be wound in a cylindrical shape, or may be wound in a flat elliptical shape or an oval shape.

  In the wound electrode body, it is preferable that both the positive electrode tab and the negative electrode tab are located on the winding center side.

  Positioning the exposed part of the positive electrode core body where the positive electrode active material layer is not formed on the outermost periphery of the wound electrode body lowers the electrical resistance of the outermost periphery, reducing heat generation during abnormalities such as nail penetration and safety. Can be improved.

  Further, the ratio of the air permeability between the R portion and the concave portion corresponding to the separator wound around the outermost periphery of the flat wound electrode body (air permeability at the concave portion equivalent / air permeability at the R portion) is hot. Battering of the battery can be further suppressed when it is 1.0 to 1.10 after pressing.

  If a film-like exterior body in which a metal layer and a resin layer are laminated is used as an exterior body of a battery provided with a flat electrode body, this film is thin and lightweight, so that the battery can be reduced in size and weight.

  The hot pressing process is performed in a state where a polytetrafluoroethylene sheet is present between the jig and the electrode body, or the surface of the pressure jig facing the electrode body is coated with polytetrafluoroethylene. If it is carried out, the peelability between the electrode body and the pressing jig after the hot pressing step is increased, and the productivity is increased.

  The volume energy density of the manufactured battery is preferably 470 Wh / L or more.

  Moreover, it is preferable that the temperature of the pressurization jig in a hot press process is 40-100 degreeC. The force applied during pressing is preferably 1 to 10 tons (tf), and the time is preferably 1 to 100 seconds.

  Further, by performing the hot pressing step after pressing (preliminary pressing) the electrode body at a pressure weaker than that of the hot pressing step, it is possible to suppress the electrode body from being rapidly pressed and to further suppress the swelling of the battery. . The preliminary pressing is preferably performed at less than 40 ° C., may be performed at normal temperature (25 ° C.), or may be performed under heated conditions, but is preferably performed at normal temperature.

  Moreover, when providing a recessed part only in one side of a pressurization jig | tool, it is preferable to set it as the structure whose depth of a recessed part is larger than the thickness of the tab which a recessed part overlaps, or the total thickness of a tab and an insulating member layer. Moreover, when providing a recessed part in both pressurization jigs, it is preferable that the sum of the depths of the opposing recessed part is larger than the thickness of the tab where the recessed part overlaps or the total thickness of the tab and the insulating member layer. .

  According to the present invention, it is possible to suppress non-uniformity in the air permeability of the separator of the flat electrode body after pressing, thereby realizing a secondary battery that can suppress an increase in battery thickness associated with charge / discharge.

FIG. 1 is a partially enlarged cross-sectional view showing a winding start portion of a flat wound electrode body. FIG. 2 is a cross-sectional view showing a hot press process. FIG. 3 is a front view showing a flat wound electrode body after hot pressing. FIG. 4 is a graph showing the relationship between the number of cycles and the thickness increase rate. FIG. 5 is a cross-sectional view showing a modification of the hot press process.

  The form for implementing this invention is demonstrated based on drawing using the example which applied this invention to the nonaqueous electrolyte secondary battery. In addition, this invention is not limited to the following form, In the range which does not change the summary, it can change suitably and can implement.

Example 1
<Preparation of positive electrode>
Lithium cobalt composite oxide (LiCoO ₂ ) as a positive electrode active material, carbon black as a conductive agent, and polyvinylidene fluoride as a binder are mixed at a mass ratio of 90: 5: 5, and N-methyl is further mixed. A positive electrode active material slurry was prepared by mixing with -2-pyrrolidone (NMP). This positive electrode active material slurry was applied to both surfaces of an aluminum positive electrode current collector (thickness 15 μm, width 102.0 mm, length 865.5 mm). At this time, the active material slurry was not applied to both ends of the core body, and the core body was left exposed. The length of the core exposed portion was 46 mm on the one hand and 236 mm on the other hand.

  This electrode plate was heated and dried to volatilize and remove NMP which was necessary when the slurry was prepared. Then, it rolled so that thickness might be set to 0.109 mm and the positive electrode plate was produced. Thereafter, an aluminum positive electrode tab (thickness 0.1 mm, width 5 mm, length 49.5 mm) is attached to the shorter core exposed portion, and an insulating tape (thickness 0.03 mm, A width of 7 mm and a length of 31.5 mm) were attached. Moreover, the tab film made from a carboxylic acid modified polypropylene was attached to the area | region where the sealing part of the laminated exterior body mentioned later and a positive electrode tab overlap. This tab film enhances adhesion with the resin layer of the laminate outer package and prevents the metal layer of the laminate outer package and the tab from coming into contact with each other by the pressure at the time of sealing. It is not a configuration.

<Preparation of negative electrode>
Graphite as a negative electrode active material, carboxymethyl cellulose (CMC) as a thickener, and styrene-butadiene rubber (SBR) as a binder are mixed at a mass ratio of 98: 1: 1, and water is further mixed. Thus, a negative electrode active material slurry was obtained. Thereafter, this negative electrode active material slurry was applied to both surfaces of a negative electrode current collector made of copper foil (thickness 8 μm, width 103.5 mm, length 830.0 mm). At this time, the active material slurry was not applied to both ends of the core body, and the core body was left exposed. The length of the core exposed portion was 78 mm on the one hand and 131 mm on the other hand.

  This electrode plate was heat-dried to volatilize and remove water necessary for the slurry preparation. Then, it rolled so that thickness might be set to 0.108 mm and the negative electrode plate was produced. Thereafter, a nickel negative electrode tab (thickness 0.1 mm, width 5 mm, length 49.5 mm) is attached to the shorter core exposed portion, and an insulating tape (thickness 0.03 mm, A width of 8 mm and a length of 31.5 mm) were attached. Moreover, the tab film made from a carboxylic acid modified polypropylene was attached to the area | region where the sealing part and negative electrode tab of the laminated exterior body mentioned later overlap.

<Production of electrode body>
The positive electrode plate and the negative electrode plate are cross-sectioned so that the positive and negative electrode bodies are on the winding start side (winding center side) and the core exposed portion of the positive electrode is on the outermost periphery through a separator made of a polyethylene microporous film. A cylindrical wound electrode body was produced by winding using a circular core.

《Preliminary press》
Thereafter, using a pressing jig having a flat pressing surface (a surface in contact with the electrode body), a preliminary press (from a direction parallel to the thickness direction of the positive electrode tab 6 and the negative electrode tab 7 at room temperature (25 ° C.)) 25 ° C., 0.4 ton for 5 seconds) to form a flat shape. As shown in FIG. 1, the electrode body 10 after the preliminary pressing includes a positive electrode 1 to which a positive electrode tab 6 is attached, a negative electrode 2 to which a negative electrode tab 7 is attached, and a separator 3 interposed between both electrodes. I have.

"hot press"
As shown in FIG. 2, the flat electrode body 10 is formed in a portion corresponding to the insulating tape 8, 8 attached on the positive electrode tab 6 and the negative electrode tab 7, with a recess 21 larger than the insulating tape 8, 8. 3 is hot-pressed (40 ° C., 60 tons for 60 seconds) from the direction parallel to the thickness direction of the positive electrode tab 6 and the negative electrode tab 7, using two pressing jigs 20 each provided with FIG. A flat electrode body having a thickness of 3.1 mm, a width L6 = 66.6 mm, and a length L7 = 105.5 mm as shown in FIG. Here, the width L1 of the insulating tape 8 is 7 mm and 8 mm, the total thickness L2 of the insulating tape 8 and the tab is 0.23 mm, the width L3 of the recess is 10 mm, the depth of the recess is L4 = 0.1 mm, and L1 <L3 , L2 <2 × L4. Further, the length of the insulating tape 8 ≦ the length L5 of the recess, and more preferably, the length of the insulating tape 8 <L5. Further, a coating layer made of polytetrafluoroethylene is formed on the surface of the pressurizing jig 20 in contact with the electrode body in order to improve the peelability.

  In the electrode body 10 after hot pressing, as shown in FIG. 3, a convex portion (a trace of the concave portion) 40 having a size larger than that of the insulating tape 8 is formed in a portion in contact with the concave portion by pressing. The distance L9 from one side of the electrode body 10 to the positive electrode tab 6 is 31.3 mm, and the distance L8 to the negative electrode tab 7 is 14.3 mm. A tab film 60 is attached to the base portions of the tabs 6 and 7 protruding from the electrode body 10.

<Preparation of non-aqueous electrolyte>
Ethylene carbonate, propylene carbonate, and diethyl carbonate are mixed at a volume ratio of 1: 1: 8 (25 ° C., 1 atm condition), and LiPF ₆ is dissolved to 1.0 M (mol / liter). It became a non-aqueous electrolyte.

<Assembly of battery>
An aluminum laminate in which a polyamide layer having a thickness of 15 μm, a dry laminate adhesive layer having a thickness of 5 μm, an aluminum layer having a thickness of 35 μm, a carboxylic acid-modified polypropylene layer having a thickness of 5 μm, and a polypropylene layer having a thickness of 25 μm was prepared. The laminate was folded so that the polyamide layer was on the outside, and the folded one was molded into a cup shape to form a storage space. The flat electrode body was housed in the housing space so that the positive and negative electrode tabs protruded from the side opposite to the folded portion. Thereafter, the two-directional end portions where the laminate films overlapped were thermally welded, and the nonaqueous electrolyte prepared by the above method was injected from the one-directional end portions which were not thermally welded. And the non-aqueous electrolyte secondary battery which concerns on Example 1 was produced by heat-welding and sealing the one direction edge part which is not heat-welded. At this time, the width of each sealing portion was 2.8 mm.

(Comparative Example 1)
A nonaqueous electrolyte secondary battery according to Comparative Example 1 was produced in the same manner as in Example 1 except that hot pressing was performed using a jig not provided with a recess.

[Cycle test]
In the same manner as above, two batteries according to Example 1 and Comparative Example 1 were produced. These batteries were charged and discharged under the following conditions, and the thickness of the batteries was measured every 100 cycles. The average value of the swelling rate calculated by the following formula is shown in FIG.

<Charging / discharging cycle conditions>
Charging: Up to 4.3V at a constant current of 1 It (3680 mA), and then until the current reaches 0.05 It (184 mA) at a constant voltage of 4.3 V Discharge: Up to 2.75 V at a constant current of 1 It (3680 mA)

  Swelling rate (%) = (thickness after n cycles−initial thickness) ÷ initial thickness × 100

  FIG. 4 shows that the swelling rate after 500 cycles is 1.7% in Example 1 and 3.8% in Comparative Example 1, which is significantly smaller in the Example.

  This is considered as follows. In Comparative Example 1, hot pressing is performed using a (flat plate-shaped) jig that does not have a recess in the tab portion. However, since the thickness of the tab portion is thicker than other portions, the tab portion is pressed strongly. The other parts will be weakly pressed. For this reason, the air permeability of the separator is large (the separator hole is small) in the strongly hot pressed part, the lithium ion permeability is deteriorated and lithium is liable to precipitate on the electrode, which causes the swelling of the battery. It becomes a factor of. Further, in the weakly pressed portion, the press is loosened due to the volume fluctuation of the electrode plate due to charge / discharge, and the battery is further swollen. On the other hand, in Example 1 in which the tab portion is provided with a recess, no direct pressing pressure is applied to the tab portion, the entire portion is pressed uniformly, and the press unbalance does not occur. Swelling is suppressed.

  In addition, when the flat electrode body after hot pressing was disassembled and the air permeability at the R portion and the air permeability at the concave portion equivalent portions (both wound around the outermost periphery of the electrode body) were measured, Example 1 The R portion was 177.3 ml / sec, the concave portion equivalent portion was 193.3 ml / sec, and the ratio (recess portion / R portion) was 1.09.

(Additions)
In the said Example, although demonstrated using the example using a laminate exterior body, this invention can also be applied to the battery using a square exterior can other than this. The electrode tab may be connected to the external terminal instead of being partially exposed to function as the external terminal.

Examples of the positive electrode active material that can be used in the present invention include LiCoO ₂ , LiNiO ₂ , LiMn ₂ O ₄ , LiMnO ₂ , LiNi _1-x Mn _x O ₂ (0 <x <1), LiNi _1-x Co _x. Lithium transition metal composite oxides such as O ₂ (0 <x <1), LiNi _x Mn _y Co _z O ₂ (0 <x, y, z <1, x + y + z = 1), and LiFePO ₄ A lithium-containing transition metal phosphate compound having an olivine structure is preferred.

Moreover, examples of the negative electrode active material that can be used in the present invention include carbon raw materials such as graphite, non-graphitizable carbon, and graphitizable carbon, titanium oxides such as LiTiO ₂ and TiO ₂ , silicon, and tin. A metalloid element, a Sn-Co alloy, or the like can be given.

  Examples of the non-aqueous solvent that can be used in the present invention include cyclic carbonates such as ethylene carbonate, propylene carbonate, and butylene carbonate, cyclic carbonates in which at least a part of hydrogen atoms are fluorinated, γ-butyllactone, Cyclic carboxylic acid esters such as γ-valerolactone, chain carbonic acid esters such as dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, methyl propyl carbonate, dinormal butyl carbonate, methyl pivalate, ethyl pivalate, methyl isobutyrate, methyl Chain carboxylic acid esters such as propionate, amide compounds such as N, N′-dimethylformamide / N-methyloxazolidinone, sulfur compounds such as sulfolane, 1-ethyl-3-methyl tetrafluoroborate Such as ambient temperature molten salt such as Le imidazolium can be exemplified. It is desirable to use a mixture of two or more of these. Among these, ethylene carbonate / propylene carbonate, chain carbonate ester, and tertiary carboxylic acid ester are particularly preferable.

As the electrolyte salt used in the present _{invention, LiPF 6, LiBF 4, LiCF} 3 SO 3, LiN (CF 3 SO 2) 2, LiN (C 2 F 5 SO 2) 2, LiN (CF 3 SO 2) (C ₄ F ₉ SO ₂ ), LiC (CF ₃ SO ₂ ) ₃ , LiC (C ₂ F ₅ SO ₂ ) ₃ , LiAsF ₆ , LiClO ₄ , Li ₂ B ₁₀ Cl ₁₀ , Li ₂ B ₁₂ Cl _{12 and the} like A mixture thereof is exemplified. Among these, LiPF ₆ (lithium hexafluorophosphate) is particularly preferable. The amount of electrolyte salt dissolved in the non-aqueous solvent is preferably 0.5 to 2.0 mol / L.

  In addition, in the non-aqueous electrolyte, as additives, vinylene carbonate, vinyl ethyl carbonate, succinic anhydride, maleic anhydride, glycolic anhydride, ethylene sulfite, divinyl sulfone, vinyl acetate, vinyl pivalate, catechol carbonate Biphenyl or the like may be added. These compounds can be used in a suitable mixture of two or more. The non-aqueous electrolyte is not limited to a liquid one, and may be a gel-like one in which the non-aqueous electrolyte is held in a polymer matrix.

  In addition, the flat electrode body in the present invention is not limited to the wound electrode body, and may be any of a laminated electrode body and an electrode body laminated in a zigzag manner.

  Moreover, as a separator, it is preferable to use the microporous film formed from polyolefin materials, such as a polypropylene and polyethylene. Moreover, in order to ensure what is called shutdown response, a low melting point resin can be mixed. Moreover, in order to acquire heat resistance, it is good also as resin laminated | stacked or blended with high melting point resin.

  Further, as shown in FIG. 5, hot pressing may be performed in a state where a polytetrafluoroethylene sheet 30 is interposed between the pressing jig 20 and the electrode body 10.

  As described above, according to the present invention, there is an excellent effect that an increase in battery thickness can be suppressed by a simple method of providing a recess in a jig used for pressing. Therefore, industrial applicability is great.

DESCRIPTION OF SYMBOLS 1 Positive electrode 2 Negative electrode 3 Separator 6 Positive electrode tab 7 Negative electrode tab 8 Insulation tape 10 Electrode body 20 Pressing jig 21 Recess 30 Polytetrafluoroethylene sheet 40 Protrusion (trace of a recess)
60 tab film

Claims (13)

An electrode body preparation step of preparing an electrode body by laminating or winding a positive electrode plate to which a positive electrode tab is attached and a negative electrode plate to which a negative electrode tab is attached via a separator;
Heating and pressing the electrode body using two pressurizing jigs to form a flat electrode body having a thickness of 4 mm or less,
The manufacturing method of the battery provided with the flat electrode body by which the recessed part is provided in the area | region which overlaps with the said positive electrode tab and the said negative electrode tab in the surface facing the said electrode body of at least one of the said pressurization jig | tool. In the manufacturing method of the battery provided with the flat electrode body according to claim 1,
An insulating member layer is provided on at least one of the positive electrode tab and the negative electrode tab,
The recess is provided in a region overlapping the insulating member layer.
A method for producing a battery comprising a flat electrode body, In the manufacturing method of the battery provided with the flat electrode body according to claim 1 or 2,
The electrode body produced in the electrode body production step is a wound electrode body.
A method for producing a battery comprising a flat electrode body, In the manufacturing method of the battery provided with the flat electrode body according to claim 3,
The positive electrode tab and the negative electrode tab are both located on the winding center side of the wound electrode body,
A method for producing a battery comprising a flat electrode body, In the manufacturing method of the battery provided with the flat electrode body according to claim 3 or 4,
The positive electrode plate includes a positive electrode core exposed portion where a positive electrode core body is exposed, and a positive electrode active material layer formed on the positive electrode core body and having the positive electrode active material,
The positive electrode core exposed portion is located on the outermost periphery of the wound electrode body,
A method for producing a battery comprising a flat electrode body, In the manufacturing method of the battery provided with the flat electrode body according to any one of claims 3 to 5,
The separator wound around the outermost periphery of the flat electrode body has a ratio of air permeability between the R portion and the concave portion (air permeability at the concave portion / air permeability at the R portion) of 1.0 to 1. 10. A method for manufacturing a battery having a flat electrode body, wherein In the manufacturing method of the battery provided with the flat electrode body according to any one of claims 1 to 6,
The battery further includes a film-shaped outer package in which a metal layer and a resin layer are laminated.
A method for producing a battery comprising a flat electrode body, In the manufacturing method of the battery provided with the flat electrode body according to any one of claims 1 to 7,
The hot pressing step is performed in a state where a polytetrafluoroethylene sheet is present between the pressing jig and the electrode body.
A method for producing a battery comprising a flat electrode body, In the manufacturing method of the battery provided with the flat electrode body according to any one of claims 1 to 7,
The surface facing the electrode body of the pressurizing jig is coated with polytetrafluoroethylene,
A method for producing a battery comprising a flat electrode body, In the manufacturing method of the battery provided with the flat electrode body according to any one of claims 1 to 9,
The volume energy density of the manufactured battery is 470 Wh / L or more,
A method for producing a battery comprising a flat electrode body, In the manufacturing method of the battery provided with the flat electrode body according to any one of claims 1 to 10,
The temperature of the pressure jig in the hot pressing step is 40 to 100 ° C.
A method for producing a battery comprising a flat electrode body, In the manufacturing method of the battery provided with the flat electrode body according to any one of claims 1 to 11,
Before the hot pressing step, further comprising a preliminary pressing step of pressing the electrode body with a pressure lower than that of the hot pressing step,
A method for producing a battery comprising a flat electrode body,     The battery provided with the flat electrode body manufactured by the manufacturing method of the battery provided with the flat electrode body of any one of Claims 1 thru | or 12.