WO2019008545A1

WO2019008545A1 - Sub-unit of electrode body, electrode unit, laminated electrode body, and energy storage element

Info

Publication number: WO2019008545A1
Application number: PCT/IB2018/054991
Authority: WO
Original assignee: リチウム・エネルギー・アンド・パワー・GmbH & Co. KG
Priority date: 2017-07-06
Filing date: 2018-07-06
Publication date: 2019-01-10
Also published as: JP2019016493A

Abstract

[Problem] The present invention addresses the problem of providing a sub-unit for a laminated electrode body with which an energy storage element having a large energy density can be efficiently manufactured. [Solution] A sub-unit of a laminated electrode body according to one embodiment of the present invention includes: two separators, each having an adhesive layer on both surfaces thereof; one positive electrode plate disposed between the two separators and adhered and fixed thereto; and one negative electrode plate adhered and fixed to the opposite surface of one of the two separators to the positive electrode plate. The ends of the two separators protrude from the ends of the positive electrode plate and the negative electrode plate.

Description

[Document name] Detail child

Patent application title: Electrode body sheet, electrode sheet, laminated electrode body and storage element

[0 0 0 1]

The present invention relates to a subunit of an electrode assembly, an electrode unit, a laminated electrode assembly, and a storage element. 【Background technology】

[0 0 0 2]

Chargeable and dischargeable storage elements are used in various devices such as mobile phones and electric vehicles. In recent years, with the increasing output and performance of these devices, storage devices that are smaller and have larger energy density (electrical capacity) are being sought.

[0 0 0 3]

In general, a storage element is formed by alternately laminating a positive electrode plate having a positive electrode active material layer formed on the surface and a negative electrode plate having a negative electrode active material layer formed on the surface via a separator having electrical insulation. It has a stacked electrode body. In order to increase the energy density per unit volume in such a storage element, it is effective to make the separator thinner. Therefore, a storage element in which a separator is formed of a resin film has been put to practical use.

[0 0 0 4]

In the storage element, a metal deposit formed by electrodeposition at the negative electrode (for example, a metal deposit due to dissolution and deposition of lithium foreign matter and metal foreign matter) may penetrate the separator and cause a short circuit between the positive electrode plate and the negative electrode plate. There is. With the use of a packaged electrode plate in which the outer edges of a pair of separators sandwiching the positive electrode plate or the negative electrode plate are adhered to form a bag, electrolytic species in the vicinity of the positive electrode plate may form precipitates There is known a laminated electrode assembly which suppresses corrosion and suppresses the electrodeposition of metal ions in contact with the negative electrode.

[0 0 0 5]

Since the bonded portion of the separator does not contribute to charge and discharge, the bonded portion of the separator may occupy a predetermined space inside the storage element, which may hinder the increase of the energy density of the storage element.

[0 0 0 6]

In the laminated electrode body, when the positive electrode plate protrudes from the negative electrode plate in plan view, current is concentrated at the end of the negative electrode plate, and electrodeposition is locally promoted. Therefore, in the laminated electrode body, the planar size of the positive electrode plate needs to be smaller than the planar size of the negative electrode plate, which is also a factor that limits the energy density of the storage element.

[0 0 0 7]

Since the separator formed from the resin film is relatively weak to heat, when the energy density of the storage element is increased, the separator is damaged by heat, and metal precipitates generated by electrodeposition penetrate the separator and the positive electrode plate There is a possibility of causing a short circuit between the and the negative electrode plate. Therefore, a storage element has been proposed in which a heat-resistant layer (inorganic layer) is formed on the surface of the separator in contact with the electrode plate to improve the heat resistance of the separator (Japanese Patent Application Laid-Open No. 20 13-14 3 3 3 7)).

【Prior Art Literature】

[Patent Document]

[0 0 0 8]

[Patent Document 1] Japanese Patent Application Laid-Open No. 2 0 1 3 1 3

SUMMARY OF THE INVENTION

[Problems to be solved by the invention]

[0 0 0 9]

In the storage element described in the above publication, a packaged positive plate in which the positive plate is sandwiched between a pair of separators and the pair of separators are adhered outside the plan view of the positive plate, and a bag larger than the positive plate and smaller than the separator A laminated electrode body in which non-packed negative electrode plates are alternately laminated is accommodated in the packaging material. A plurality of packaged positive electrode plates and a plurality of negative electrode plates are held by sandwiching the plurality of separators with the outer layer material at the outer peripheral portion.

[0 0 1 0] As described above, when alternately stacking a plurality of packaged positive electrode plates and a plurality of negative electrode plates, it is difficult to accurately position the negative electrode plate in the laminated electrode body. Since it is necessary to form the positive electrode plate small so that the positive electrode plate does not protrude from the negative electrode plate, improvement in energy density is hindered. In addition, even if the positive electrode plate is made smaller, it is necessary to position and position the negative electrode plate accurately on the packaged positive electrode plate, so the work of laminating a plurality of packaged positive electrode plates and a plurality of negative electrode plates is required. It is cumbersome and limits the improvement of manufacturing efficiency.

[0 0 1 1]

An object of the present invention is to provide a multilayer electrode sub-unit, an electrode unit, and a multilayer electrode body capable of efficiently producing a storage element having a large energy density, and a storage element using them.

[Means for Solving the Problems]

[0 0 1 2]

The sheet of the laminated electrode assembly according to one aspect of the present invention comprises: two separators having adhesive layers on both sides; and one positive electrode plate disposed and adhesively fixed between the two separators. A single negative electrode plate adhered and fixed to one surface of the two separators opposite to the positive electrode plate, and an end portion of the two separators is the positive electrode plate and the negative electrode plate. Project from the end of the

【Effect of the invention】

[0 0 1 3]

The subunits of the laminated electrode assembly according to one aspect of the present invention include one positive electrode plate, two separators sandwiching the positive electrode plate, and one negative electrode plate stacked on one separator. Because they are fixed and integrated, the relative positions of the positive plate, the separator and the negative plate within this subunit are accurate and unchanged. Therefore, even if the area in which the positive electrode plate and the negative electrode plate face each other is increased, the subunit does not protrude from the negative electrode plate to promote electrodeposition. Further, in the sub-unit, since the positive electrode plate and the negative electrode plate are adhered and fixed to the separator, the separator is unlikely to be deformed. Therefore, the subunits can be easily positioned by the guide, and multiple sheets can be accurately and quickly stacked. By using such a sheet, it is possible to efficiently manufacture a laminated electrode body having a relatively large ratio of the area of the region where the positive electrode plate and the negative electrode plate are opposed to the area of the separator and a large energy density.

Brief Description of the Drawings

[0 0 1 4]

FIG. 1 is a schematic cross-sectional view of a buffer according to an embodiment of the present invention.

FIG. 2 is a partial enlarged cross-sectional view of the subunit of FIG.

3 is a schematic cross-sectional view of an electrode sheet having the buffer of FIG. 1;

4 is a schematic plan view of the electrode unit of FIG. 3;

5 is a schematic cross-sectional view of a laminated electrode body having the storage battery of FIG. 3;

6 is a schematic exploded perspective view of a storage element having the laminated electrode assembly of FIG.

7 is a schematic view showing a process of forming the substrate of FIG. 1. FIG.

MODE FOR CARRYING OUT THE INVENTION

[0 0 1 5]

[0 0 1 6]

In the sub-unit, one positive electrode plate, two separators sandwiching the positive electrode plate, and one negative electrode plate stacked on one separator are bonded and integrated to form an integrated circuit. Within the unit, the relative positions of the positive electrode plate, the separator and the negative electrode plate are accurate and unchanged. Therefore, even if the area in which the positive electrode plate and the negative electrode plate face each other is enlarged, the sub-units It does not protrude from the negative electrode plate to promote electrodeposition. Further, in the subunit, the positive electrode plate and the negative electrode plate are adhered and fixed to the separator, so the separator is not easily deformed. Therefore, subunits can be easily positioned by guides, and multiple subunits can be stacked accurately and quickly. By using the subunits, the ratio of the area of the region where the positive electrode plate and the negative electrode plate are opposite to the area of the separator is relatively large, and a stacked electrode body having a large energy density can be efficiently produced.

[0 0 1 7]

In the subunit, a porous resin layer in which the two separators are disposed between the adhesive layers, an oxidation resistant layer between the adhesive layer in the surface facing the positive electrode plate and the resin layer And the adhesive layer may exhibit adhesiveness when heated. According to this configuration, the adhesive layer does not exhibit adhesiveness at normal temperature, so the handling of the subject is easy, and the adhesive layer exhibits adhesiveness by heating, so that other subunits are produced. And can be easily joined. In addition, the separator has a resin layer holding an electrolyte and an oxidation resistant layer that suppresses oxidation of the resin layer between adhesive layers on both sides, so that the resin layer holds a sufficient electrolyte. Will be secured. In addition, since the oxidation resistant layer can be a relatively thin layer that can be easily broken, the resin layers of the separator should be welded together when the laminated sheet is laminated to form a laminated electrode body. It is possible to facilitate the manufacture of the laminated electrode assembly.

[0 0 1 8]

The electrode sheet according to an aspect of the present invention is formed by laminating a plurality of the above-described sheets, and separators protruding from the end portions of the positive electrode plate and the negative electrode plate of each of the plurality of sheets are welded. It is done. In the electrode unit, the relative position between the plurality of sheets is fixed by welding the separators, and the positive electrode plate and the negative electrode plate of each sheet must be held in the correct facing state. Can. Therefore, the electrode unit can increase the area in which the positive electrode plate and the negative electrode plate face each other, so that the energy density of the laminated electrode body formed using the electrode assembly can be increased. it can.

[0 0 1 9]

In the electrode assembly, the negative electrode plate may not be force-bonded to the separator of the negative electrode plate adjacent to the negative electrode plate. According to this configuration, the electrode unit can be easily manufactured only by laminating a plurality of sheets and welding the end of the separator.

[0 0 2 0]

In the laminated electrode body according to an aspect of the present invention, a plurality of the electrode units described above are laminated, and one negative electrode plate is disposed on the separator disposed in the outermost layer. The laminated electrode body can be easily manufactured since it can be obtained by laminating a plurality of electrode units, and the energy density is large.

[0 0 2 1]

The laminated electrode body may further include a resin film covering a laminated body of the plurality of electrode units and the negative electrode plate. According to this configuration, the resin film suppresses the positional displacement between the electrode units, so that the energy density can be further increased, and the resin film protects the negative electrode plate of the outermost layer. Becomes easy.

[0 0 2 2]

A storage element according to one aspect of the present invention includes: the above-described stacked electrode body; a case for housing the stacked electrode body; and an external terminal electrically connected to the stacked electrode body and exposed from the case. Prepare. Since the accumulator device includes the laminated electrode body, it is easy to manufacture and can increase the energy density.

[0 0 2 3]

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.

[0 0 2 4]

1 and 2 show a subunit S according to an embodiment of the present invention. This subunit S, as shown in FIG. 3 and FIG. 4 itself, is used to manufacture an electrode assembly U according to another embodiment of the present invention. In addition, as shown in FIG. 5, the electrode unit U is itself used to manufacture a laminated electrode body B according to still another embodiment of the present invention. Furthermore, as shown in FIG. 6, the stacked electrode body B is used as one component of a storage element according to another embodiment of the present invention.

[0 0 2 5]

As shown in FIG. 1, the subunit S includes two separators 1, one positive electrode plate 2 disposed between the two separators 1 and adhesively fixed, and one of the two separators 1. And one negative electrode plate 3 bonded and fixed to the opposite surface. In the sheet, the ends of the two separators 1 project from the ends of the positive plate 2 and the negative plate 3.

[0 0 2 6]

As shown in detail in FIG. 2, the separator 1 comprises a sheet-like resin layer 4, an oxidation resistant layer 5 laminated on the surface of the resin layer 4 facing at least the positive electrode plate 2, the resin layer 4 and And a pair of adhesive layers 6 laminated on both sides of the laminate of the oxidation resistant layer 5.

[0 0 2 7]

Separator 1 is an electric storage device manufactured using subunit S, and is interposed between positive electrode plate 2 and negative electrode plate 3 to prevent direct contact between positive electrode plate 2 and negative electrode plate 3. The inside thereof is impregnated with an electrolytic solution to enable transfer of charges via ions between the positive electrode plate 2 and the negative electrode plate 3.

[0 0 2 8]

The resin layer 4 of the separator 1 is a layer mainly holding an electrolytic solution, and is formed of a porous resin film.

[0 0 2 9]

The main component of the resin layer 4 is, for example, polyethylene (PE), polypropylene (PP), ethylene-acetate-butyl copolymer, ethylene-methyl atarelate copolymer, ethylene-butyl atylate copolymer, polyolefin derivatives such as chlorinated polyethylene, etc. Polyolefins such as ethylene-propylene copolymer, and polyesters such as polyethylene terephthalate and copolymerized polyester can be employed. Among them, polyethylene and polypropylene, which are excellent in electrolytic solution resistance, durability and weldability, are preferably used as the main component of the resin layer 4. The term "main component" means a component having the largest mass content.

[0 0 3 0]

The lower limit of the average thickness of the resin layer 4 is preferably, and more preferably 10 m. On the other hand, the upper limit of the average thickness of the resin layer 4 is preferably 3 0 / x m, more preferably 2 0 / x m. By setting the average thickness of the resin layer 4 to the above lower limit or more, it is possible to prevent the resin layer 4 from being broken when the separators 1 are welded. In addition, by setting the average thickness of the resin layer 4 to the above-described upper limit or less, the energy density of the substrate S and hence the laminated electrode body B can be increased.

[0 0 3 1]

The oxidation resistant layer 5 of the separator 1 is a layer mainly provided to suppress oxidation and deterioration of the resin layer 4 and includes a large number of inorganic particles and a binder connecting the inorganic particles.

[0 0 3 2]

As a main component of the inorganic particles, for example, oxides such as alumina, silica, zirconia, titanium oxide, magnesium, ceria, yttria, zinc oxide, iron oxide, nitrides such as silicon nitride, titanium nitride, boron nitride and the like , Silicon carbide, calcium carbonate, aluminum sulfate, aluminum hydroxide, potassium titanate, talc, kaolin clay, kaolinite, halloysite, pyrophyllite, montmorillonite, sericite, myite, phamateite, bentonite, Examples include asbestos, zeolite, calcium borate and magnesium benzoate. Among them, as the main component of the inorganic particles of the oxidation resistant layer 5, alumina, silica and titanium are particularly preferable. [0 0 3 3]

The lower limit of the average particle size of the inorganic particles of the oxidation resistant layer 5 is preferably 1 nm, more preferably 7 nm. On the other hand, the upper limit of the average particle size of the inorganic particles is preferably 5 / x m, more preferably 1 / x m. By setting the average particle diameter of the inorganic particles to the lower limit or more, the ratio of the binder in the oxidation resistant layer 5 can be reduced, and the heat resistance of the oxidation resistant layer 5 can be increased. In addition, by setting the average particle size of inorganic particles to the above-described upper limit or less, it is possible to form a homogeneous oxidation resistant layer 5. The “average particle size” is a value measured according to JIS-R1660 using a transmission electron microscope (T E M) or a scanning electron microscope (S E M).

[0 0 3 4]

The main component of the binder of the oxidation resistant layer 5 is, for example, fluorocarbon resin such as poly (vinyl fluoride), poly (tetrafluoroethylene), fluoro rubber such as poly (vinyl fluoride) -hexafluoropropylene-tetrafluoroethylene copolymer, styre -Butadiene copolymer and its hydride, acrylonitrile butadiene copolymer and its hydride, acrylonitrile butadiene-styrene copolymer and its hydride, methacrylate ester-acrylate ester copolymer, styrene Synthetic rubber such as acrylic ester copolymer, acrylonitrile acrylic ester copolymer etc., carboxymethyl cellulose (CMC), hydroxy cellulose (HEC), cellulose derivative such as ammonium salt of carboxymethyl cellulose, polyetherimiPolyamides such as poly, polyamidoimides, polyamides and their precursors (polyamic acid etc.), ethylene-acrylic acid copolymers such as ethylene / ethyl atalylate copolymer, polybul alcohol (PVA), polybul butyral (PVB And polyvinylidene-pyrrolidone (PVP), polyvinyl acetate-bi-nore, polyurethane, polyphenylene-le-tenole, poly-noselephone, poly-e-tenoreth / rehon, poly-phenylene-nephride, polyester and the like.

[0 0 3 5]

The lower limit of the average thickness of the oxidation resistant layer 5 is preferably 4 / x m. On the other hand, the upper limit of the average thickness of the oxidation resistant layer 5 is preferably 6 / x m, and is more preferable. By setting the average thickness of the oxidation resistant layer 5 to the above lower limit or more, it is possible to prevent the oxidation resistant layer 5 from being broken when the separator 1 is bonded and fixed. Further, by setting the average thickness of the oxidation resistant layer 5 to the above-mentioned upper limit or less, the oxidation resistant layer 5 is easily broken at the time of welding of the separators 1 to one another, so that the resin layers 4 can be integrated reliably.

[0 0 3 6]

The adhesive layer 6 of the separator 1 is a layer which has ion conductivity so as to enable electrode reaction in the positive electrode plate 2 and the negative electrode plate 3 and which bonds the separator 1 to the positive electrode plate 2 and the negative electrode plate 3. . Specifically, the adhesive layer 6 is preferably a layer that exhibits adhesiveness by heating, and a temperature exceeding normal temperature, for example, a temperature of 60 ° C. or more and a shut-down temperature of the separator 1 (the resin layer 4 It is configured such that adhesion can be developed when exposed to a temperature lower than the melting temperature (the temperature at which the adhesion is developed is 60 ° C. or more and less than the shutdown temperature of separator 1). By forming the adhesive layer 6 so as to exhibit positive adhesion in such a temperature range, the adhesive layer 6 does not exhibit adhesiveness at normal temperature, which facilitates the handling of the sheet U, and other structures By heating the adhesive layer 6 to such an extent that the element is not damaged, the adhesive layer 6 can be easily bonded to the other substrate U by exhibiting adhesiveness.

[0 0 3 7]

The adhesive layer 6 can be formed from a mixed material containing particles exhibiting ion conductivity and a binder. Specifically, the adhesive layer 6 is formed of a material containing solid electrolytic solution particles containing an electrolytic solution to secure ion conductivity, and a binder exhibiting adhesiveness by, for example, heating or ultrasonic vibration. be able to. The adhesive layer 6 preferably has continuous pores so that liquids and gases can pass through.

[0 0 3 8]

The lower limit of the average thickness of the adhesive layer 6 is preferably 0.1 / xm, more preferably 0.2 / xm, and still more preferably 0.4 m. On the other hand, as the upper limit of the average thickness of the adhesive layer 6, Preferably, 3 / xm is more preferable, and 1.2 / xm is more preferable. Sufficient adhesion can be obtained by setting the average thickness of the adhesive layer 6 to the above lower limit or more. Further, by setting the average thickness of the adhesive layer 6 to the upper limit or less, sufficient ion conductivity can be obtained.

[00 3 9]

Examples of the material of the solid electrolyte particles of the adhesive layer 6 include inorganic solid electrolytes, pure solid polymer electrolytes, and polymer gel electrolytes (gel electrolytes), among which ions are among others. A polymer gel electrolyte which can increase the conductivity and is uniform and easy to adjust the particle size is particularly preferably used.

[0040]

The polymer gel electrolyte is one which is made easy to handle by gelling the electrolyte with a polymer. Examples of the polymer that gels the electrolytic solution may include, for example, a fluorinated poly (vinylidene methacrylate) copolymer, polymethyl methacrylate, polyacrylonitrile and the like.

【004 1】

As the electrolyte of the polymer gel electrolyte, an organic electrolyte in which the supporting electrolyte is dissolved in an organic solvent is used. A lithium salt is preferably used as the supporting electrolyte. The lithium salt is not particularly limited. For example, L i PF 6 L i A s F ₆ L i BF ₄ L i S b F ₆ L i A 1 C 1 4, L i C 1 O ₄ , CF 3 SO 3 L i, C 4 F 9 SO 3 L i, CF 3 COO L i,

(CF 3 CO) ₂ NL i (CF 3 SO ₂ ) ₂ NL i, (C ₂ F 5 SO ₂ ) NL i and the like. Among _{them, L i PF 6 L i C} 1 0 4 CF 3 SO 3 L i which indicates a high degree of dissociation soluble in organic solvents are particularly preferred.

[004 2]

The organic solvent used in the electrolytic solution is not particularly limited as long as it can dissolve the supporting electrolytic solution, but, for example, dimethyl carbonate (DMC), ethylene carbonate (EC), diethylen carbonate (DEC), propylene Carbonates such as carbonate (PC), butylene carbonate (BC), methyl ethyl carbonate (MEC), for example, y-butyric acid latatone, esters such as methyl formate, for example, 12-dimethoxetane, tetrahydrofuran Ethers such as furan and the like, sulfur-containing compounds such as sulfolane and dimethylsulfoxide etc. can be used alone or in combination. Among them, carbonates having a high dielectric constant and a wide stable potential region are particularly preferably used.

[004 3]

The lower limit of the concentration of the supporting electrolyte in the electrolyte is 1 mass. Is preferred, 5 mass. / ₀ is more preferable. On the other hand, the upper limit of the concentration of the supporting electrolyte in the electrolyte is 30 mass. / ₀ is preferred, 20 mass. / ₀ is more preferable. By setting the concentration of the support electrolyte in the electrolyte within the above range, relatively large ion conductivity can be obtained.

[0044]

The lower limit of the average particle size of the solid electrolyte particles is preferably 0.1 μm, and more preferably 0.2 m. On the other hand, the upper limit of the average particle size of the solid electrolytic solution particles is preferably 2 / xm, more preferably 1 m. By setting the average particle diameter of the solid electrolytic solution particles to the above lower limit or more, it becomes easy to bring the solid electrolytic solution particles into contact with each other to impart ion conductivity to the adhesive layer 6. In addition, by setting the average particle diameter of the solid electrolytic solution particles to the upper limit or less, it becomes easy to form the adhesive layer 6 in a uniform film shape.

[004 5]

The shape of the solid electrolyte particles is preferably a shape having a small sphericity, such as a rod shape, a pyramid shape, or a plate shape, so as to promote the contact between the solid electrolyte particles and to increase the ion conductivity.

[004 6]

The binder for the adhesive layer 6 may be any one as long as it has adhesiveness to the solid electrolyte particle and the positive electrode active material layer 8, but heating to a relatively low temperature makes it possible to It is preferable to use a tacky resin, that is, a polymer material having a relatively low glass transition temperature and exhibiting tackiness. [0 0 4 7]

The lower limit of the glass transition temperature of the binder is preferably 50.degree. C., more preferably 45.degree. On the other hand, the upper limit of the glass transition temperature of the binder is preferably 50.degree. C., more preferably 45.degree. By setting the glass transition point of the binder to the lower limit or more, the strength of the adhesive layer 6 can be secured. In addition, by setting the glass transition point of the binder to the upper limit or less, the separator 1 can be bonded to the positive electrode plate 2 and the opposing separator 1 at a temperature at which the resin layer 4 is not damaged.

[0 0 4 8]

As a main component of a binder, an acrylic polymer etc. are mentioned, for example. As the acrylic polymer, a tolyl group-containing acrylic polymer containing a monomer unit having a tolyl group and a (meth) acrylic acid ester monomer unit is suitably used. Here, the monomer unit having a ditolyl group is a structural unit obtained by polymerizing, for example, acrylonitrile, methacrylonitrile or the like, and the (meth) acrylate monomer unit is, for example, CH z: ^ ^ ¹ — COOR

² (in the formula, R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group or a cycloalkyl group) A monomer unit derived from a compound represented by the formula: The ditolyl group-containing acrylic polymer is formed by polymerizing an ethylenically unsaturated acid monomer in addition to a monomer unit having a ditolyl group and a (meth) acrylic acid ester monomer unit. It may contain an ethylenically unsaturated acid monomer unit. In addition, the acrylic polymer having a tolyl group may be crosslinked.

[0 0 4 9]

The lower limit of the ratio of solid electrolyte particles in the adhesive layer 6 is Ί 0 mass. / ₀ is preferred, 80 mass. / ₀ is more preferable. On the other hand, the upper limit of the ratio of the solid electrolyte particles in the adhesive layer 6 is preferably 95% by mass, and more preferably 90% by mass. By setting the ratio of the solid electrolytic solution particles in the adhesive layer 6 to the lower limit or more, it is possible to impart sufficient ion conductivity to the adhesive layer 6. Further, by setting the ratio of the solid electrolytic solution particles in the adhesive layer 6 to the above-mentioned upper limit or less, the adhesive layer 6 can be provided with sufficient adhesiveness by setting the ratio of the binder relatively to a certain level or more.

[0 0 5 0]

The positive electrode plate 2 has a conductive foil- or sheet-like positive electrode current collector 7 and a positive electrode active material layer 8 laminated on the surface of the positive electrode current collector. More specifically, the positive electrode plate 2 includes an active material region having a rectangular shape in plan view in which the positive electrode active material layer 8 is stacked on the surface of the positive electrode current collector 7, and the positive electrode current collector 7 from the active material region. And a positive electrode tab 9 (see FIG. 4) extending in a band smaller than the active material region.

[0 0 5 1]

As a material of the positive electrode current collector 7 of the positive electrode plate 2, a metal such as aluminum, copper, iron, nickel or an alloy thereof is used. Among these, aluminum, an aluminum alloy, copper and a copper alloy are preferable, and aluminum and an aluminum alloy are more preferable, from the viewpoint of the balance between the height of conductivity and the cost. In addition, as a formation form of the positive electrode current collector 7, a foil, a vapor deposition film, etc. may be mentioned, and a foil is preferable in terms of cost. That is, aluminum foil is preferable as the positive electrode current collector 7. In addition, as aluminum or aluminum alloy, A 1 0 8 5 P, A 3 0 0 3 P, etc. specified in J I S- H 4 0 0 0 (2 0 1 4) can be exemplified.

[0 0 5 2]

The lower limit of the average thickness of the positive electrode current collector 7 is preferably 5 / xm, more preferably 10 / xm. On the other hand, the upper limit of the average thickness of the positive electrode current collector 7 is preferably 50 / xm , 40 / xm is more preferable. By setting the average thickness of the positive electrode current collector 7 to the lower limit or more, sufficient strength can be imparted to the positive electrode current collector 7. In addition, by setting the average thickness of the positive electrode current collector 7 to the upper limit or less, the energy density of the substrate S and thus the laminated electrode body B can be increased.

[0 0 5 3]

The positive electrode active material layer 8 is formed of a so-called positive electrode mixture containing a positive electrode active material. In addition, the positive electrode composite material for forming the positive electrode active material layer 8 may be a conductive agent, a binder, a thickener, a filler, etc., if necessary. Contains optional ingredients.

[00 54]

As the positive electrode active material, for example, a composite oxide (L i _x C o 0 ₂ , L i _x N i 0 ₂ , L i represented by L i _x MO _y (where M represents at least one transition metal)) _x Mn ₂ 0 ₄ , L i _x M n 3 3, L i _x N i _α C o (i- _a ) 0 ₂ , L i _x N i _a Mn _{/ 3} C o (i- _α- β) 0 ₂ , L i _x N i _a Mn (2-a) 0 _{4 and the} like, L i _w M _x (XO _y ) _z (Me represents at least one transition metal, and X represents, for example, P, S i, B, V And the like (polycarbonate compounds represented by L i F e P 0 ₄ , L i Mn P 0 ₄ , L i N i PO ₄ , L i C o P 0 ₄ , L i ₃ V ₂ (PO ₄ )) ₃ , L i ₂ Mn S i 0 ₄ , L i ₂ C o P 0 ₄ F, etc.). The elements or polyions in these compounds may be partially substituted with other elements or species. In the positive electrode active material layer 8, one of these compounds may be used alone, or two or more thereof may be mixed and used. The crystal structure of the positive electrode active material is preferably a layered structure or a spinel structure.

[00 5 5]

The lower limit of the content of the positive electrode active material in the positive electrode active material layer 8 is 50 mass. / ₀ is preferred, 70 mass. / ₀ is more preferable, 80 mass. / ₀ is more preferable. On the other hand, the upper limit of the content of the positive electrode active material is 99 mass. / ₀ is preferred, 94 mass. / ₀ is more preferable. By setting the content of the positive electrode active material particles in the above range, it is possible to increase the energy density of the substrate S and thus the laminated electrode body B.

[00 5 6]

The conductive agent is not particularly limited as long as the conductive material does not adversely affect the battery performance. As such a conductive agent, carbon black such as natural or artificial graphite, furnace black, acetylene black and ketjen black, metal, conductive ceramics and the like can be mentioned. The shape of the conductive agent may, for example, be powdery or fibrous.

[00 5 7]

The lower limit of the content of the conductive agent in the positive electrode active material layer 8 is 0.1 mass. / ₀ is preferred, 0.5 mass. / ₀ is more preferable. On the other hand, the upper limit of the content of the conductive agent is 10 mass. / ₀ is preferred, 5 mass. / ₀ is more preferable. By setting the content of the conductive agent in the above range, the energy density of the subunit S and, in turn, the laminated electrode body B can be increased.

[00 5 8]

Examples of the binder include thermoplastic resins such as fluorine resin (polytetrafluoroethylene (PTF E), polyfluorinated biphenyl (PVDF), etc.), polyethylene, polypropylene, polyimide, etc., for example, ethylene propylene rubber (E PDM) And sulfonated EPDM, styrene butadiene rubber (SBR), elastomers such as fluororubber, and polysaccharide macromolecules.

[00 5 9]

The lower limit of the binder content in the positive electrode active material layer 8 is 1 mass. / ₀ is preferred, 2 mass. / ₀ is more preferable. On the other hand, the upper limit of the binder content is 10 mass. / ₀ is preferred, 5 mass. / ₀ is more preferable. By setting the content of the binder in the above range, the positive electrode active material can be stably held.

[00 6 0]

Examples of the thickener include polysaccharide polymers such as carboxymethylcellulose (CMC) and methylcellulose. When the thickener has a functional group that reacts with lithium, it is preferable to deactivate the functional group beforehand by methylation or the like.

[00 6 1]

The filler is not particularly limited as long as it does not adversely affect the battery performance. As the main component of the filler, polypropylene, polyethylene and other polyolefins, silica, alumina, zeolite, glass, carbon and the like can be mentioned.

[00 6 2]

The lower limit of the average thickness of the positive electrode active material layer 8 is preferably 10 / xm, more preferably 20 / xm. Yes. On the other hand, the upper limit of the average thickness of the positive electrode active material layer 8 is preferably 100 / xm, more preferably 80m. The positive electrode reaction can be sufficiently activated by setting the average thickness of the positive electrode active material layer 8 to the above lower limit or more. In addition, by setting the average thickness of the positive electrode active material layer 8 to the above-described upper limit or less, the energy density of the substrate S and thus the laminated electrode body B can be increased.

[0 0 6 3]

The negative electrode plate 3 has a conductive foil- or sheet-like negative electrode current collector 10 and a negative electrode active material layer 11 laminated on the surface of the negative electrode current collector 10. Specifically, the negative electrode plate 3 has an active material region having a rectangular shape in plan view, in which an active material layer is stacked on the surface of the negative electrode current collector 10, and a strip having a width smaller than that of the active material region from this active material region. , And a negative electrode tab 1 2 (see FIG. 4) spaced apart from the positive electrode tab 9 and extending in the same direction as the positive electrode tab 9.

[0 0 6 4]

The negative electrode current collector 10 of the negative electrode plate 3 can have the same configuration as that of the positive electrode current collector 7 described above, but as a material, copper or a copper alloy is preferable. That is, copper foil is preferable as the negative electrode current collector 10 of the negative electrode plate 3. Examples of copper foils include rolled copper foils and electrolytic copper foils.

[0 0 6 5]

The negative electrode active material layer 11 is formed of a so-called negative electrode plate composite material containing a negative electrode active material. Further, the negative electrode plate composite material forming the negative electrode active material layer 11 contains optional components such as a conductive agent, a binder, a thickener, and a filler, as necessary. As the optional components such as the conductive agent, the binder, the thickener, and the filler, those similar to the positive electrode active material layer 8 can be used.

[0 0 6 6]

As the negative electrode active material, a material capable of inserting and extracting lithium ions is preferably used. Specific examples of the negative electrode active material include metals such as lithium and lithium alloy, metal oxides, polyphosphate compounds, and carbon materials such as graphite and amorphous carbon (graphitizable carbon or non-graphitizable carbon). Etc.

[0 0 6 7]

Among the above-mentioned negative electrode active materials, from the viewpoint of setting the discharge capacity per unit opposing area between the positive electrode plate 2 and the negative electrode plate 3 in an appropriate range, Si, Si oxide, Sn, Sn oxide or these oxides It is preferable to use the combination of and particularly preferable to use Si oxide. Note that 3 1 and 3 1 can have a discharge capacity about three times that of graphite when made into an oxide.

[0 0 6 8]

When using a Si oxide as the negative electrode active material, the ratio of the number of atoms to Si of O contained in the Si oxide is preferably more than 0 and less than 2. That is, a compound represented by S i O _x (0 <X <2) is preferable as the S i oxide. The ratio of the number of atoms is more preferably 0.5 or more and 1.5 or less.

【0 0 6 9】

As the negative electrode active material, those mentioned above may be used alone or in combination of two or more. For example, by mixing and using Si oxide and another negative electrode active material, the discharge capacity per unit opposing area of the positive electrode plate 2 and the negative electrode plate 3 and the above-mentioned positive electrode active with respect to the mass of the negative electrode active material described later. Both mass ratios of the substances can be adjusted to be suitable values. Other negative electrode active materials used in combination with the S i oxide include carbon materials such as graphite, hard carbon, soft carbon, cotas, acetylene black, ketjen black, vapor grown carbon fiber, fullerene, activated carbon and the like. Be One of these carbon materials may be mixed with the S i oxide, or two or more may be mixed with the S i oxide in any combination and ratio. Among these other negative electrode active materials, graphite having a relatively low charge / discharge potential is preferable. By using graphite, a secondary battery element with high energy density can be obtained. Examples of the graphite mixed with the S i oxide include scaly graphite, spherical graphite, artificial graphite, natural graphite and the like. Among these, scale-like graphite is preferred which easily maintains contact with the surface of the Si oxide particles even after repeated charge and discharge.

[0 0 7 0]

Furthermore, the negative electrode active material layer 1 1 contains a small amount of B, N, P, F, C 1, B r in addition to the S i oxide. And typical nonmetal elements such as Li, Na, Mg, Al, K, Ca, Zn, Ga, Ge and the like metallic elements, Sc, Ti, V, Cr And transition metals such as Mn, Fe, Co, Ni, Cu, Mo, Zr, Ta, Hf, Nb, and W may be contained.

[0 0 7 1]

It is preferable to use what contains both the phases of S i 0 ₂ and S i as said S i oxide (substance represented by general formula S i O _x ). Such a Si oxide occludes and desorbs lithium in Si in the matrix of Si ₂ O ₂ , so that the volume change is small and the charge-discharge cycle characteristics are excellent.

[0 0 7 2]

The average particle diameter of the Si oxide is preferably 1 μm to 15 μm. By setting the average particle diameter of the Si oxide to the above-described upper limit or less, the charge-discharge cycle characteristics of the substrate S and, consequently, the laminated electrode body B can be improved.

[0 0 7 3]

The Si oxides can be used from highly crystalline ones to amorphous ones. Furthermore, as the Si oxide, one that has been washed with an acid such as hydrogen fluoride or sulfuric acid or one that has been reduced with hydrogen may be used.

[0 0 7 4]

The lower limit of the content of S i oxide in the negative electrode active material is 30 mass. / ₀ is preferred, 50 mass. / _{0 is} more preferable, 70 mass. / ₀ is more preferable. On the other hand, the upper limit of the Si oxide content is usually 100 mass. / ₀ , 90 mass. / ₀ is preferable.

[0 0 7 5]

The lower limit of the content of the negative electrode active material in the negative electrode active material layer 11 is 60 mass. / ₀ is preferred, 80 mass. / ₀ is more preferable, and 90% by mass is more preferable. On the other hand, the upper limit of the content of the negative electrode active material is 99 mass. / ₀ is preferred, 9 8 mass. / ₀ is more preferable. By setting the content of the negative electrode active material particles in the above range, it is possible to increase the energy density of the subunit S and hence the laminated electrode body B.

[0 0 7 6]

As a lower limit of the content of the binder in the negative electrode active material layer 11, 1 mass. Is preferred, 5 mass. / ₀ is more preferable. On the other hand, the upper limit of the binder content is 20 mass. / ₀ is preferred, 15 mass. / ₀ is more preferable. By setting the content of the binder in the above range, the negative electrode active material can be stably held.

[0 0 7 7]

The lower limit of the average thickness of the negative electrode active material layer 11 is preferably 10 / x m, more preferably 20 / x m. Conversely, the upper limit of the average thickness of the negative electrode active material layer 11 is preferably 100 / x m, more preferably 80 / x m. The negative electrode reaction can be sufficiently activated by setting the average thickness of the negative electrode active material layer 11 to the above lower limit or more. In addition, by setting the average thickness of the negative electrode active material layer 11 to the above-described upper limit or less, the energy density of the substrate S and thus the stacked electrode body B can be increased.

[0 0 7 8]

In the step s, a step of disposing one positive electrode plate 2 between two separators 1 and disposing one negative electrode plate 3 on one of the two separators 1 Step of heating and pressing in a state in which one negative electrode plate 3, one of the two separators 1, one positive electrode plate 2 and the other of the two separators 1 are laminated in this order. (Heat and pressure process) and a process of cutting the two separators 1 so that both side edges of the two separators 1 protrude from the side edges of the positive electrode plate 2 and the negative electrode plate 3 (cutting process) And a method comprising

[0 0 7 9]

The sheet forming step may be performed by using a separator 1 which has been cut first and cut to the dimensions in the sheet S in advance, but as shown in FIG. After performing the placement process and bonding heating and pressing process continuously using the sheet-like separator base material 1 a By carrying out the cutting step, the substrate S can be produced continuously and efficiently. [0 0 8 0]

Specifically, in the disposing step, the two separator base materials 1a are continuously supplied and transported in the long direction, and the size of the final product is measured between the two separator base materials 1a in this transport state. The positive plate 2 cut into two pieces is sequentially inserted at equal intervals (a pitch equal to the width of the subunit S), and the size of the final product is cut so as to face the positive plate 2 on the outside of one separator base material 1a. The arranged negative electrode plates 3 are sequentially arranged.

[0 0 8 1]

In the unit heating and pressing step, the long laminate is heated and pressurized while being conveyed continuously. Heating and pressurization may be performed simultaneously. Alternatively, the laminate may be pressed after heating before the temperature of the adhesive layer 6 of the separator 1 drops to a temperature at which it loses adhesion.

[0 0 8 2]

Continuous conveyance of the laminate of the separator base material 1a, the positive electrode plate 2 and the negative electrode plate 3 can be performed using, for example, a conveyance belt or the like having releasability.

[0 0 8 3]

The heating of the laminate in the sheet heating and pressing step can be performed using, for example, a plate heater H or the like disposed so as to sandwich the laminate. In addition, pressurization in the unit heating and pressing process can be performed using, for example, a pair of pressure rollers P sandwiching the laminate. Alternatively, heating and pressing may be performed simultaneously using a pair of heating rollers which sandwich and heat the laminate.

[0 0 8 4]

The heating temperature in the sheet heating and pressing step is not lower than the temperature at which the adhesive layer 6 of the separator 1 develops adhesive strength and lower than the shutdown temperature of the resin layer 4, for example, 80 ° C. or higher. It can be less than ° C.

[0 0 8 5]

The pressure per unit length of the pressure roller can be, for example, not less than 0.1 NZ cm and not more than 10.0 NZ cm as a pressure applied in the sheet heating and pressing process.

[0 0 8 6]

In the cutting step, the sheets S are sequentially separated by cutting the separator base material 1 a with a cutter C to form a separator 1 of a predetermined length.

[0 0 8 7]

In the subunit S, since the negative electrode plate 3, one separator 1, the positive electrode plate 2 and the other separator 1 are laminated in this order and adhered and fixed, the relative positions of the two separators 1, the positive electrode plate 2 and the negative electrode plate 3 Position is maintained. For this reason, in the subunit S, even if the difference in size between the positive electrode plate 2 and the negative electrode plate 3 is reduced, the positive electrode plate 2 does not protrude from the negative electrode plate 3 in plan view to promote electrodeposition. In addition, in the subunit S, the difference in size between the negative electrode plate and the separator can be reduced. As a result, the area of the positive plate 2, that is, the positive plate 2 and the negative plate 3, is smaller than the projected area of the subunit S (the area when viewed from the stacking direction of the separator 1, the positive plate 2 and the negative plate 3). In this case, the energy density can be increased by relatively increasing the area of the area to which the electrode plate contributes.

[0 0 8 8]

Further, in the subunit S, since the positive electrode plate 2 and the negative electrode plate 3 are adhered and fixed in addition to the outer edge portion of the separator 1, the separator 1 is difficult to stagnate. For this reason, by using the subunit S, by placing a guide or the like on the outer edge of the separator 1, it is possible to position and stack the sub-pieces S relatively accurately and quickly. It is possible to efficiently produce a laminated electrode body B having a large value. Subunit S is added to two separators 1 and one positive electrode plate 2 as compared with the case of using a packed positive electrode plate in which a conventional positive electrode plate is accommodated in a bag-shaped separator. As one negative electrode plate 3 larger than the positive electrode plate 2 is further integrated, the effect of suppressing the stagnation of the separator 1 is greater. Because of this, the subunit S can position the separator 1 more accurately, so the energy density is larger. Can form a laminated electrode assembly.

[0 0 8 9]

An electrode unit U according to an embodiment of the present invention, as shown in FIG. 3, has a plurality of subunits S and protrudes from the end portions of the positive electrode plate 2 and the negative electrode plate 3 of the plurality of substrates S. The ends of the separators 1 are welded together.

[0 0 9 0]

In this electrode unit U, the positive electrode plate 2 is bonded and fixed to the separators 1 on both sides, but the negative electrode plate 3 is bonded and fixed only to the separator 1 of the same subunit S, and the adjacent It is not adhesively fixed to the separator 1.

[0 0 9 1]

As shown in FIG. 4, in the electrode unit U, a first welding region R 1 is formed along a pair of opposing side edges where the positive electrode tab 9 and the negative electrode tab 12 of the positive electrode plate 2 and the negative electrode plate 3 do not exist. It is preferable that Further, the electrode unit U is formed by partially welding a plurality of separators 1 along the side edge where the positive electrode tab 9 and the negative electrode tab 12 of the positive electrode plate 2 and the negative electrode plate 3 are present and the side edge opposite thereto. Two welding areas R2 may be formed. In this case, it is preferable that the first welding area R 1 and the second welding area R 2 are not formed in the vicinity of the corners of the separator 1. Each separator is bent in the thickness direction of the positive electrode plate 2 and the negative electrode plate 3 along the side edges of the positive electrode plate 2 and the negative electrode plate 3 in order to bring the plurality of separators 1 into close contact with each other. In this case, since bending in different directions interferes, welding at this part may cause excessive load and damage to the separator 1.

[0 0 9 2]

The number of sheets S included in the electrode sheet U can be, for example, 5 or more and 15 or less. By setting the number of laminated layers of subunit S in this range, the distance between the separators 1 on both outer sides does not become too large. As a result, it protrudes from the end of positive electrode plate 2 and negative electrode plate 3 of each subunit S Even if the length of the separator 1 is reduced, the end portions of the separator 1 can be bundled and welded to integrate the plurality of subunits S, so that the usage amount of the separator 1 can be reduced.

[0 0 9 3]

The electrode unit U includes a process of laminating a plurality of subunits S (subunit laminating process), and a plurality of separators S protruding from the end of the positive electrode plate 2 and the negative electrode plate 3 of the plurality of laminated substrates S And a step of welding (welding step). Further, in the method of manufacturing the electrode unit U, the step of trimming the outer portions of the plurality of welded separators 1 (trimming step), and the welded portions of the plurality of separators 1 along the side edges of the positive plate 2 and the negative plate 3 And the step of bending (folding step).

[0 0 9 4]

In the subunit lamination step, a plurality of subunits S are oriented in the same direction and laminated. As a result, a plurality of positive electrode plates 2 and a plurality of negative electrode plates 3 are alternately disposed with the separator 1 in between, and a laminate in which the separators 1 are disposed further outside the outermost positive electrode plate 2 is formed.

[0 0 9 5]

A stack of a plurality of sheets S is, for example, using a guide or the like that abuts on the outer edge of the square of the separator 1 and sequentially guides the sheets S formed in the above-described sheet forming step. It is possible to do it relatively quickly and accurately by putting in and putting up the sheets S by gravity.

[0 0 9 6]

In the welding step, the end portions of all the separators 1 are bundled and welded so as to be in close contact with each other. Specifically, the oxidation resistant layer 5 of the separator 1 is broken to weld the resin layers 4 together. For this reason, welding of the separator 1 is preferably performed using an ultrasonic vibration indenter (horn).

[0 0 9 7]

Also, by using, for example, a large number of fine projections formed on the contact surface as an ultrasonic vibration indenter, the oxidation resistant layer 5 is broken, and fragments of the oxidation resistant layer 5 are separated. Resin layer 4 It is possible to weld together efficiently. The projections of the ultrasonic vibration indenter are preferably in the shape of a quadrangular frustum, which are arranged at equal intervals in the vertical and horizontal directions. Such projections can be easily formed by forming grooves at regular intervals on the surface of the ultrasonic vibration indenter, and efficiently destroy the oxidation resistant layer 5 to securely weld the separator 1. be able to.

[0 0 9 8]

In the trimming process, the portions protruding to the outside of the welding regions R1, R2 of the separator 1 are cut off. The separator 1 is designed to have the minimum size that can form the welding regions R 1 and R 2, but by bundling the plurality of separators 1 in close contact with each other in the welding step, the two-dot chain lines in FIG. As the end of the separator 1 is shifted in a step-like manner depending on the thickness of the positive electrode plate 2 and the negative electrode plate 3, the welding regions R 1 and R 2 formed in the portion where all the separators 1 are stacked. The separator 1 will protrude to the outside. Therefore, in this trimming step, the portions projecting in a step-like manner outside the welding regions R 1 and R 2 are mainly cut off. As a result, when the laminated electrode body B is formed, the energy density of the laminated electrode body B can be increased by reducing the dead space occupied by the separator 1 outside the welding regions R 1 and R 2. .

[0 0 9 9]

In the bending step, portions of the separator 1 that project from the positive electrode plate 2 and the negative electrode plate 3 are bent along the side edges of the positive electrode plate 2 and the negative electrode plate 3. As a result, when the laminated electrode body B is formed, the energy density of the laminated electrode body B can be increased by reducing the dead space occupied by the portions protruding from the positive electrode plate 2 and the negative electrode plate 3 of the separator 1. .

[0 1 0 0]

In the electrode unit U, the relative positions of the plurality of subunits S are maintained by welding all the separators 1 to the body. For this reason, the plurality of positive electrode plates 2 and negative electrode plates 3 are alternately stacked on both sides of the separator 1 so as to face each other with relative accuracy. Therefore, the electrode sheet can increase the energy density by increasing the facing area of the positive plate 2 and the negative plate 3.

[0 1 0 1]

As shown in FIG. 5, a plurality of electrode units U are stacked, and a single negative electrode plate 3 is disposed on the separator 1 disposed in the outermost layer, as shown in FIG. 5. . That is, the stacked electrode assembly B includes: a plurality of stacked electrode units U; and one negative electrode plate 3 disposed further outside of the separator 1 disposed at the outermost side in the stacked body of the electrode units U Have.

[0 1 0 2]

It should be noted that “one negative electrode plate is disposed on the separator” is not intended to limit the vertical relationship between the plurality of electrode units U and the further negative electrode plate 3, and is stacked on the outermost side 2 Of the two electrode sheets u, one of the electrode sheets U in which the negative electrode plate 3 is in contact with the separator 1 of the adjacent electrode unit U. Further outside the separator 1 opposite to the negative electrode plate 3 of the electrode sheet U It means that a further negative electrode plate 3 is laminated. Therefore, a plurality of electrode stacks U may be stacked on one negative electrode plate 3.

[0 1 0 3]

In the laminated electrode body B, each negative electrode plate 3 is bonded and fixed not only to the separator 1 of the same subunit S but also to the separator 1 of the adjacent subunit S. In addition, the laminated electrode body B further includes a resin film 13 covering the entire laminated body (the outer periphery of the laminated body) of the plurality of electrode sheets U and one further negative electrode plate 3.

[0 1 0 4]

Although the thickness of the separator 1, the positive electrode plate 2 and the negative electrode plate 3 is drawn large in the figure for easy understanding, the actual thickness of the separator 1, the positive electrode plate 2 and the negative electrode plate 3 is small. The thickness of the welding regions R 1 and R 2 of the plurality of separators 1 is very small compared to the width of the welding regions R 1 and R 2. Therefore, the portions of the electrode unit U that project from the positive electrode plate 2 and the negative electrode plate 3 including the first welding region R 1 of the separator 1 are bent along the side edges of the positive electrode plate 2 and the negative electrode plate 3. It is also good. [0 1 0 5]

Examples of the main component of the resin film 13 include polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET) and the like. Among them, as a main component of the resin film 13, polypropylene having a good heat sealability is particularly preferable.

[0 1 0 6]

The lower limit of the average thickness of the resin film 13 is preferably 20 / xm, more preferably 50 / xm. On the other hand, the upper limit of the average thickness of the resin film 13 is preferably 150 / xm, more preferably 100 / xm. By making the average thickness of the resin film 13 equal to or more than the above lower limit, it is possible to prevent the positional deviation of the plurality of electrode sheets U and the negative electrode plate 3 and to protect the negative electrode plate 3 without breakage. it can. Further, by making the average thickness of the resin film 13 equal to or less than the above upper limit, it is possible to coat the laminate of the plurality of electrode sheets U and the negative electrode plate 3 easily and without gaps, so The effect of preventing the misalignment of the soot U and the negative electrode plate 3 can be ensured, which contributes to the improvement of the energy density of the laminated electrode body B.

[0 1 0 7]

In the laminated electrode body B, a step of laminating a plurality of electrode units U (electrode unit laminating step) and a step of arranging one negative electrode plate 3 on the separator 1 arranged in the outermost layer (negative plate arranging step) And a step of heating and pressing the plurality of electrode stacks U and the negative electrode plate 3 in a stacked state (electrode heating and pressing step). In addition, in the method of manufacturing this laminated electrode body B, a step of covering the outer periphery of the laminate of the plurality of electrode sheets U and the negative electrode plate 3 with a resin film 13 before the electrode body heating and pressing step Preferably, the method further comprises a film wrapping step).

[0 1 0 8]

In the electrode unit laminating step, a plurality of electrode units u are oriented in the same direction and laminated. That is, between adjacent two electrode units U, the separator 1 of the other electrode unit U abuts the negative electrode plate 3 of one electrode unit U. Thus, a laminate in which a plurality of positive electrode plates 2 and negative electrode plates 3 are stacked via the separator 1 is formed.

[0 1 0 9]

In the negative electrode plate disposing step, the negative electrode plate 3 is disposed on both outer sides by further laminating the negative electrode plate 3 on the outer side of the separator 1 disposed in the outermost layer, and the plurality of positive electrode plates 2 and the negative electrode plates 3 are respectively separators Form a laminated body alternately stacked via 1.

[0 1 1 0]

In the resin film rubbing process, the laminate of a plurality of electrode sheets U and one additional negative electrode plate 3 is covered with a resin film 13 to obtain a plurality of electrode films in the next electrode body heating and pressing process. Hold the U and negative plate 3 so that they do not shift.

[0 1 1 1]

As described above, the resin film 13 prevents positional deviation of the separator 1, positive electrode plate 2 and negative electrode plate 3 in the electrode body heating and pressing process, thereby providing a margin for positional deviation of the positive electrode plate 2 and negative electrode plate 3. Can be made smaller to make the facing area of the positive electrode plate 2 and the negative electrode plate 3 larger, and the energy density of the laminated electrode body B can be further improved.

【0 1 1 2】

In addition, the resin film 13 covering the laminate of the plurality of electrode sheets U and the negative electrode plate 3 protects the negative electrode plate 3 on both outer sides, and in particular, the manufacture of a storage element described later can be facilitated.

【0 1 1 3】

In the electrode body heating and pressing step, adjacent sheets S are preferably formed by heating and pressing a laminate of a plurality of electrode sheets U and one negative electrode plate 3 covered with a resin film 13. The separator 1 and the negative electrode plate 3 are joined to each other between the outer electrode sheet U and the outermost electrode sheet U. As a result, a laminated electrode body B in which all the separators 1, the positive electrode plate 2 and the negative electrode plate 3 are adhered and fixed to each other is obtained.

【0 1 1 4】

An electricity storage device according to one embodiment of the present invention, as shown in FIG. And a positive electrode external terminal 15 and a negative electrode external terminal 16 which are connected to the positive electrode tab 9 and the negative electrode tab 12 of the laminated electrode body B and are exposed from the case 14. . In the storage element, an electrolytic solution is enclosed in the case 14 together with the laminated electrode body B.

【0 1 1 5】

The case 14 has a bottomed square cylindrical case body 17 and a plate-like lid 18 for sealing the opening of the case body 17. The positive electrode external terminal 15 and the negative electrode external terminal 16 are provided to pass through the lid 18.

[0 1 1 6]

The storage element is attached to the positive electrode external terminal 15 and the negative electrode external terminal 16 inside the case 14 and the positive electrode connecting member 1 9 to which the positive electrode tab 9 and the negative electrode tab 12 of the laminated electrode body B are connected. And a negative electrode connecting member 20.

【0 1 1 7】

Case 14 is a sealed container that accommodates the stacked electrode assembly B and in which the electrolytic solution is sealed. 【0 1 1 8】

The material of the case 14 may be, for example, a resin or the like as long as it has a sealing property capable of sealing the electrolyte and a strength capable of protecting the laminated electrode body B, but metal is preferably used. Ru. In other words, the case 14 may be, for example, a flexible bag formed of a laminate film, but a rigid metal case capable of more reliably protecting the laminated electrode B may be used. preferable.

【0 1 1 9】

As the electrolytic solution to be sealed together with the laminated electrode B in Case 14, a known electrolytic solution generally used for the storage element can be used. For example, ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC) And lithium carbonate in a solvent containing cyclic carbonate such as JETyl carbonate (DEC), linear carbonate such as jetyl carbonate (DEC), dimethinole carbonate (DMC), and ethenole methinole carbonate (EMC). A solution in which (L i PF ₆ ) or the like is dissolved can be used.

[0 1 20]

The storage element includes a step of housing the laminated electrode body B in the case 14 (stacked electrode body housing step) and a step of filling the electrolytic solution in the case 14 (electrolyte filling step).

[0 1 2 1]

In the laminated electrode body accommodation step, the positive electrode tab 9 and the negative electrode tab 12 are respectively connected to the positive electrode connecting member 19 and the negative electrode connecting member 20, and then the laminated electrode body B is inserted into the case main body 17 Seal the opening of case body 17 with body 18

[0 1 2 2]

As a method of connecting the positive electrode tab 9 and the negative electrode tab 12 to the positive electrode connecting member 19 and the negative electrode connecting member 20, for example, ultrasonic welding, laser welding, caulking or the like can be employed.

【0 1 2 3】

In the electrolyte filling step, the electrolyte is injected into the case 14. For this purpose, the case 14 is preferably provided with a sealable inlet.

[0 1 24]

Since the storage element has a large energy density and uses the laminated electrode body B that can be manufactured efficiently, the energy density is large and the manufacturing can be performed efficiently.

【0 1 2 5】

The above embodiment does not limit the configuration of the present invention. Therefore, the above embodiment can omit, replace, or add the components of the above embodiments based on the description in the present specification and technical common sense, and all of them can be construed as belonging to the scope of the present invention. It should.

【0 1 2 6】

In the electrode sheet, separators and negative plates may be adhered and fixed between adjacent electrode sheets.

【0 1 2 7】 In the laminated electrode body, the separator and the negative electrode plate may not be adhesively fixed between the adjacent electrode sheets.

【0 1 2 8】

The laminated electrode body may have only one electrode sheet.

【0 1 2 9】

The laminated electrode body may have no resin film.

[0 1 3 0]

In the storage element, the positive electrode external terminal may be omitted, the positive electrode tab may be connected to a case (for example, a lid plate), and the case may serve as an external terminal.

【Industrial applicability】

[0 1 3 1]

The method of manufacturing a stacked electrode assembly and the method of manufacturing a storage element according to the present invention can be used to manufacture various storage elements, but in particular, vehicles such as electric vehicles and plug-in hybrid electric vehicles (PHEVs) It is preferably used to manufacture a secondary battery used as a power source of

[Description of the code]

【0 1 3 2】

1 Seno Pass. Rater

2 Positive plate

3 Negative plate

4 resin layer

5 Oxidation resistant layer

6 Adhesive layer

7 Positive current collector

8 Positive electrode active material layer

9 Positive tab

10 Negative current collector

1 1 Negative electrode active material layer

1 2 Negative electrode tab

1 3 Resin film

1 4 Case

1 5 Positive external terminal

1 6 Negative external terminal

1 7 Case body

1 8 lid

1 9 Positive electrode connection member

20 negative electrode connection member

B stacked electrode body

C Katsuta

H plate heater

P pressure roller

S Subunit

U electrode set

Claims

【Document Name】 Scope of Claims

[Claim 1]

Two separators with adhesive layers on both sides,

One positive plate disposed and adhesively fixed between the two separators;

One negative electrode plate adhered and fixed to the surface of the two separators opposite to the positive electrode plate;

An end portion of the two separators protrudes from an end portion of the positive electrode plate and the negative electrode plate.

[Claim 2]

The two separators each have a porous resin layer disposed between the adhesive layers, and an oxidation resistant layer between the adhesive layer and the resin layer on the side facing the positive electrode plate,

The laminate of a laminated electrode body according to claim 1, wherein the adhesive layer develops adhesiveness when heated.

[Claim 3]

A plurality of the subunits according to claim 1 or claim 2 are stacked,

An electrode unit in which separators projecting from end portions of the positive electrode plate and the negative electrode plate of each of the plurality of substrates are welded.

[Claim 4]

The electrode unit according to claim 3, wherein the negative electrode plate and the separator of the subunit adjacent to the negative electrode plate are not bonded.

[Claim 5]

A plurality of electrode units according to claim 3 or claim 4 are stacked,

A stacked electrode assembly, wherein one negative electrode plate is disposed on the separator disposed in the outermost layer.

[Claim 6]

The laminated electrode body according to claim 5, further comprising a resin film covering a laminate of the plurality of electrode sheets and the negative electrode plate.

[Claim 7]

A laminated electrode body according to claim 5 or claim 6,

A case for housing the laminated electrode body;

An external terminal electrically connected to the laminated electrode body and exposed from the case;

A storage element comprising: