JP2019053862A - Laminated electrode body and power storage element - Google Patents

Abstract

To provide a laminated electrode body which can be efficiently manufactured and has large energy density.SOLUTION: A laminated electrode body according to one embodiment of the present invention includes: a positive electrode plate; a negative electrode plate which is laminated on the positive electrode plate; and a separator sandwiched between the positive electrode plate and the negative electrode plate. The separator includes: a porous resin layer; and an adhesive layer which is intermittently formed and directly opposite to the positive electrode plate or the negative electrode plate. The adhesive layer is arranged so as to leave an adhesive absence region continuous from the outer edge of the separator in a plan view of the separator.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a laminated electrode body and a storage element.

  Chargeable / dischargeable storage elements are used in various devices such as mobile phones and electric vehicles. In recent years, with higher output and higher performance of these devices, there is a demand for a power storage element that is smaller and has a higher energy density (electric capacity).

  In general, a storage element is formed by alternately stacking a positive electrode plate having a positive electrode active material layer formed on a surface and a negative electrode plate having a negative electrode active material layer formed on a surface through an electrically insulating separator. It has an 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. For this reason, the electrical storage element which formed the separator with the resin film is put in practical use.

  In a power storage device, metal deposits generated by electrodeposition in the negative electrode (for example, metal deposits due to dissolution and precipitation of lithium dendrite or metal foreign matter) may penetrate the separator and cause a short circuit between the positive electrode plate and the negative electrode plate. . A metal electrode that generates metal ions capable of forming precipitates is mixed in the electrolyte solution in the vicinity of the positive electrode plate by using a bag-shaped electrode plate formed by bonding the outer edges of a pair of separators sandwiching the positive electrode plate or the negative electrode plate into a bag shape. A laminated electrode body that suppresses this and prevents electrodeposition of metal ions in contact with the negative electrode is known.

  Since the bonded portion of the separator formed outside the positive electrode plate or the negative electrode plate in plan view does not contribute to charging / discharging, the bonded portion of the separator occupies a predetermined space inside the power storage element and prevents the energy density of the power storage element from being increased. obtain.

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

  Since the separator formed from the resin film is relatively weak against heat, when the energy density of the energy storage device 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 short-circuiting the negative electrode plate. For this reason, a power storage element has been proposed in which a heat-resistant layer (inorganic layer) is formed on the surface of the separator that comes into contact with the electrode plate to improve the heat resistance of the separator (see JP 2013-143337 A).

JP 2013-143337 A

  In the electricity storage device described in the above publication, a positive electrode plate is sandwiched between a pair of separators, and a packaged positive electrode plate in which the pair of separators are bonded to each other on the outside in plan view, and a bagging larger than the positive electrode plate and smaller than the separator. A laminated electrode body in which negative electrode plates that are not formed are alternately laminated is accommodated in an exterior material. A plurality of packed positive plates and a plurality of negative plates are held by sandwiching a plurality of separators with an exterior material at the outer periphery.

  Thus, when laminating a plurality of packaged positive plates and a plurality of negative plates alternately, it is difficult to accurately position the negative plates in the laminated electrode body. Since it is necessary to make 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. Even if the positive electrode plate is made smaller, it is necessary to accurately position and dispose the negative electrode plate on the packaged positive electrode plate. Therefore, the work of laminating a plurality of packaged positive electrode plates and a plurality of negative electrode plates is difficult. It is complicated and the improvement of production efficiency is limited.

  An object of the present invention is to provide a laminated electrode body and a storage element that can be efficiently manufactured and have a high energy density.

  A laminated electrode body according to an aspect of the present invention includes a positive electrode plate, a negative electrode plate laminated on the positive electrode plate, and a separator sandwiched between the positive electrode plate and the negative electrode plate, and the separator is a porous resin layer. And an adhesive layer that is intermittently formed and directly faces the positive electrode plate or the negative electrode plate, and the adhesive layer leaves an adhesive non-existing region continuous from the outer edge of the separator in a plan view of the separator. Arranged so that.

  The laminated electrode body according to one embodiment of the present invention can be efficiently manufactured and has a high energy density.

It is a typical disassembled perspective view of the electrical storage element of one Embodiment of this invention. It is typical sectional drawing of the laminated electrode body of the electrical storage element of FIG. It is typical sectional drawing of the subunit of the laminated electrode body of FIG. FIG. 4 is a schematic plan view of the subunit of FIG. 3. 3 is a partial enlarged cross-sectional view of the subunit.

  A laminated electrode body according to an aspect of the present invention includes a positive electrode plate, a negative electrode plate laminated on the positive electrode plate, and a separator sandwiched between the positive electrode plate and the negative electrode plate, and the separator is a porous resin layer. And an adhesive layer that is intermittently formed and directly faces the positive electrode plate or the negative electrode plate, and the adhesive layer leaves an adhesive non-existing region continuous from the outer edge of the separator in a plan view of the separator. Arranged so that.

  Since the separator has an adhesive layer, the laminated electrode body is bonded to at least one of the positive electrode plate and the negative electrode plate, so that the relative position between the separator and at least one of the positive electrode plate and the negative electrode plate is accurate and unchanged. For this reason, the laminated electrode body is easy to accurately laminate the positive electrode plate and the negative electrode plate, and the positive electrode plate protrudes from the negative electrode plate even when the opposing area between the positive electrode plate and the negative electrode plate is increased. Is promoted. Further, since the laminated electrode body is arranged so that the adhesive layer remains in a region where no adhesive is present from the outer edge of the separator, it is possible to efficiently impregnate the entire separator with the electrolytic solution through the region where the adhesive is absent. it can. For this reason, the said laminated electrode body can be manufactured efficiently, and its energy density is large.

  It is preferable that the shape of the adhesive layer in the plan view of the separator is a plurality of wavy line patterns arranged in parallel to each other. According to this configuration, the separator can be uniformly and firmly bonded to the positive electrode plate or the negative electrode plate by the adhesive layer.

  It is preferable that an average amplitude of the wavy line pattern is equal to or greater than an average interval of the wavy line patterns. According to this configuration, when the separator is cut in a straight line, the cutting line always crosses the wavy pattern regardless of the cutting direction, so the adhesive non-existing region reaches the outer edge of the separator in the portion where the wavy pattern is cut, The introduction of the electrolytic solution can be promoted. In addition, with this configuration, when the separator is cut into a square shape, there are always cut portions of the wavy pattern on each of the four sides, so that the outer peripheral portion of the pair of separators sandwiching the positive electrode plate or the negative electrode plate is connected to the positive electrode plate or the negative electrode plate It is possible to securely bond outside the surface.

  It is preferable that the average width of the wavy line pattern is 0.2 to 5 times the average interval of the wavy line pattern. According to this configuration, it is easy to infiltrate the electrolyte solution through the adhesive non-existing region while securing the adhesive force.

  It is preferable that an average width of the wavy line pattern is 0.5 mm or more and 5 mm or less. According to this configuration, the effect of rapidly impregnating the electrolytic solution into the porous resin layer immediately below the wavy line pattern while obtaining a sufficient adhesive force can be further ensured.

  The electrical storage element which concerns on another aspect of this invention is equipped with the said multilayer electrode body and the case which accommodates the said multilayer electrode body. Since the power storage element uses the laminated electrode body, it can be efficiently manufactured and has a high energy density.

  “Wavy line” means a line shape that bends periodically and repeatedly. For example, a sine wave shape, a rectangular wave shape, a triangular wave shape, a sawtooth wave shape, or any other waveform can be repeated. .

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

  In FIG. 1, the structure of the electrical storage element which concerns on one Embodiment of this invention is shown. The power storage element includes a laminated electrode body 1 and a case 2 that houses the laminated electrode body 1. In the case 2, an electrolytic solution is enclosed together with the laminated electrode body 1.

  As shown in FIG. 2, the stacked electrode body 1 includes a plurality of positive plates 3, a plurality of negative plates 4 that are alternately stacked with the positive plates 3, and a plurality of sandwiched between the positive plates 3 and the negative plates 4. And a separator 5. Moreover, it is preferable that the laminated electrode body 1 has the resin film 6 which has the insulation which covers the outer periphery of the laminated body of the some positive electrode plate 3, the negative electrode plate 4, and the separator 5. FIG.

  The laminated electrode body 1 is formed by laminating a plurality of electrode units U each formed of n positive plates 3 and negative plates 4 and 2n separators 5 and one additional negative plate 4. (N is a natural number).

  Each electrode unit U can be formed by stacking a plurality of subunits S. As shown in FIG. 3, the subunit S includes two separators 5, one positive electrode plate 3 disposed between the two separators 5 and bonded and fixed thereto, and two separators 5. One of the separators is provided with one negative electrode plate 4 which is bonded and fixed to the surface opposite to the positive electrode plate 3.

  The positive electrode plate 3 includes a conductive foil-shaped or sheet-shaped positive electrode current collector 7 and a positive electrode active material layer 8 laminated on the surface of the positive electrode current collector 7. More specifically, the positive electrode plate 3 has a rectangular active material region in which the positive electrode active material layer 8 is laminated on the surface of the positive electrode current collector 7, and the positive electrode current collector 7 is activated from the active material region. And a positive electrode tab 9 (see FIG. 4) extending in a strip shape having a width smaller than that of the material region.

  As a material of the positive electrode current collector 7 of the positive electrode plate 3, 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 from the balance between high conductivity and cost, and aluminum and an aluminum alloy are more preferable. Moreover, as a formation form of the positive electrode electrical power collector 7, foil, a vapor deposition film, etc. are mentioned, A foil is preferable from the surface of cost. That is, the positive electrode current collector 7 is preferably an aluminum foil. Examples of aluminum or aluminum alloy include A1085P and A3003P defined in JIS-H4000 (2014).

  The lower limit of the average thickness of the positive electrode current collector 7 is preferably 5 μm and more preferably 10 μm. On the other hand, the upper limit of the average thickness of the positive electrode current collector 7 is preferably 50 μm, and more preferably 40 μm. By setting the average thickness of the positive electrode current collector 7 to be equal to or more than the lower limit, sufficient strength can be imparted to the positive electrode current collector 7. Moreover, the energy density of the laminated electrode body 1 can be increased by setting the average thickness of the positive electrode current collector 7 to the upper limit or less.

  The positive electrode active material layer 8 is formed from a so-called positive electrode mixture containing a positive electrode active material. Moreover, the positive electrode mixture forming the positive electrode active material layer 8 includes optional components such as a conductive agent, a binder, a thickener, and a filler as necessary.

Examples of the positive electrode active material include complex oxides (Li _x CoO ₂ , Li _x NiO ₂ , Li _x Mn ₂ O ₄ , Li _x ) represented by Li _x MO _y (M represents at least one transition metal). _{MnO 3, Li x Ni α Co} (1-α) O 2, Li x Ni α Mn β Co (1-α-β) O 2, Li x Ni α Mn (2-α) O 4 , etc.), Li _w A polyanion compound (LiFePO ₄ , LiMnPO ₄ , LiNiPO ₄ , LiCoPO ₄ ) represented by Me _x (XO _y ) _z (Me represents at least one transition metal, and X represents, for example, P, Si, B, V, etc.) Li ₃ V ₂ (PO ₄ ) ₃ , Li ₂ MnSiO ₄ , Li ₂ CoPO ₄ F, etc.). The elements or polyanions in these compounds may be partially substituted with other elements or anion species. In the positive electrode active material layer 8, one kind of these compounds may be used alone, or two or more kinds may be mixed and used. The crystal structure of the positive electrode active material is preferably a layered structure or a spinel structure.

  As a minimum of content of the positive electrode active material in the positive electrode active material layer 8, 50 mass% is preferable, 70 mass% is more preferable, 80 mass% is further more preferable. On the other hand, as an upper limit of content of a positive electrode active material, 99 mass% is preferable and 94 mass% is more preferable. By making content of a positive electrode active material more than the said minimum, the energy density of the laminated electrode body 1 can be enlarged. Moreover, the intensity | strength of the positive electrode active material layer 8 is securable by making content of a positive electrode active material below the said upper limit.

  The conductive agent is not particularly limited as long as it is a conductive material that does not adversely affect battery performance. Examples of such a conductive agent include carbon black such as natural or artificial graphite, furnace black, acetylene black, and ketjen black, metals, and conductive ceramics. Examples of the shape of the conductive agent include powder and fiber.

  As a minimum of content of a conductive agent in cathode active material layer 8, 0.1 mass% is preferred and 0.5 mass% is more preferred. On the other hand, as an upper limit of content of a electrically conductive agent, 10 mass% is preferable and 5 mass% is more preferable. By setting the content of the conductive agent within the above range, it is possible to increase the energy density of the stacked electrode body 1 and thus the power storage element.

  Examples of the binder include thermoplastic resins such as fluorine resin (polytetrafluoroethylene, polyvinylidene fluoride, etc.), polyethylene, polypropylene, polyimide, etc., such as ethylene-propylene-diene rubber (EPDM), sulfonated EPDM, styrene butadiene rubber, fluorine. Examples thereof include elastomers such as rubber, polysaccharide polymers, and the like.

  As a minimum of content of the binder in the positive electrode active material layer 8, 1 mass% is preferable and 2 mass% is more preferable. On the other hand, the upper limit of the binder content is preferably 10% by mass, and more preferably 5% by mass. By setting the binder content within the above range, the positive electrode active material can be stably held.

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

  The filler is not particularly limited as long as it does not adversely affect battery performance. Examples of the main component of the filler include polyolefins such as polypropylene and polyethylene, silica, alumina, zeolite, glass, and carbon.

  As a minimum of average thickness of positive electrode active material layer 8, 10 micrometers is preferred and 20 micrometers is more preferred. On the other hand, the upper limit of the average thickness of the positive electrode active material layer 8 is preferably 100 μm, and more preferably 80 μm. By setting the average thickness of the positive electrode active material layer 8 to the above lower limit or more, the positive electrode reaction can be sufficiently activated. In addition, by setting the average thickness of the positive electrode active material layer 8 to the upper limit or less, the energy density of the laminated electrode body 1 and thus the power storage element can be increased.

  The negative electrode plate 4 includes a conductive foil-shaped or sheet-shaped 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 4 has a rectangular active material region in which the active material layer is laminated on the surface of the negative electrode current collector 10, and a band shape that is narrower than the active material region from the active material region. The positive electrode tab 9 and a negative electrode tab 12 (see FIG. 4) extending in the same direction as the positive electrode tab 9 with a space therebetween.

  The negative electrode current collector 10 of the negative electrode plate 4 can have the same configuration as the positive electrode current collector 7 described above, but the material is preferably copper or a copper alloy. That is, the negative electrode current collector 10 of the negative electrode plate 4 is preferably a copper foil. Examples of the copper foil include rolled copper foil and electrolytic copper foil.

  The negative electrode active material layer 11 is formed from a so-called negative electrode plate mixture containing a negative electrode active material. Moreover, the negative electrode plate mixture forming the negative electrode active material layer 11 includes optional components such as a conductive agent, a binder, a thickener, and a filler as necessary. The same components as those of the positive electrode active material layer 8 can be used as optional components such as a conductive agent, a binder, a thickener, and a filler.

  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 alloys, metal oxides, polyphosphate compounds such as carbon materials such as graphite and amorphous carbon (easily graphitizable carbon or non-graphitizable carbon). Is mentioned.

  Among the negative electrode active materials, Si, Si oxide, Sn, Sn oxide, or a combination thereof is used from the viewpoint of setting the discharge capacity per unit facing area between the positive electrode plate 3 and the negative electrode plate 4 within a suitable range. It is particularly preferable to use Si oxide. Si and Sn can have a discharge capacity about three times that of graphite when they are made into oxides.

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

  As the negative electrode active material, those described above may be used singly or in combination of two or more. For example, by using a mixture of Si oxide and another negative electrode active material, the discharge capacity per unit facing area between the positive electrode plate 3 and the negative electrode plate 4 and the mass of the negative electrode active material described later with respect to the mass of the negative electrode active material described later. Both of the mass ratios can be adjusted to be suitable values. Other negative electrode active materials used in combination with Si oxide include carbon materials such as graphite, hard carbon, soft carbon, coke, acetylene black, ketjen black, vapor grown carbon fiber, fullerene, activated carbon and the like. . Only one kind of these carbon materials may be mixed with Si oxide, or two or more kinds may be mixed with Si oxide in an arbitrary combination and ratio. Among these other negative electrode active materials, graphite having a relatively low charge / discharge potential is preferable, and a secondary battery element having a high energy density can be obtained by using graphite. Examples of graphite used by mixing with Si oxide include flaky graphite, spherical graphite, artificial graphite, and natural graphite. Among these, scaly graphite that can easily maintain contact with the surface of the Si oxide particles even after repeated charge and discharge is preferable.

  Furthermore, the negative electrode active material layer 11 includes a small amount of typical nonmetallic elements such as B, N, P, F, Cl, Br, and I, Li, Na, Mg, Al, K, Ca, Zn in addition to Si oxide. Typical metal elements such as Ga, Ge, and transition metal elements such as Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Mo, Zr, Ta, Hf, Nb, and W may be contained. .

As the Si oxide (substance represented by the general formula SiO _x ), it is preferable to use a material containing both phases of SiO ₂ and Si. Such an Si oxide has a small volume change and excellent charge / discharge cycle characteristics because lithium is occluded and released in Si in the SiO ₂ matrix.

  The average particle size of the Si oxide is preferably 1 μm or more and 15 μm or less. By making the average particle diameter of the Si oxide not more than the above upper limit, the charge / discharge cycle characteristics of the laminated electrode body 1 can be improved.

  The Si oxide can be used from highly crystalline to amorphous. Further, as the Si oxide, one washed with an acid such as hydrogen fluoride or sulfuric acid or one reduced with hydrogen may be used.

  As a minimum of content of Si oxide in a negative electrode active material, 30 mass% is preferred, 50 mass% is more preferred, and 70 mass% is still more preferred. On the other hand, the upper limit of the content of Si oxide is usually 100% by mass, and preferably 90% by mass. By setting the content of the Si oxide in the negative electrode active material within the above range, the discharge cycle characteristics of the multilayer electrode body 1 can be improved.

  As a minimum of content of the negative electrode active material in the negative electrode active material layer 11, 60 mass% is preferable, 80 mass% is more preferable, 90 mass% is further more preferable. On the other hand, as an upper limit of content of a negative electrode active material, 99 mass% is preferable and 98 mass% is more preferable. By setting the content of the negative electrode active material within the above range, it is possible to increase the energy density of the multilayer electrode body 1 and, in turn, the power storage element.

  As a minimum of content of the binder in the negative electrode active material layer 11, 1 mass% is preferable and 5 mass% is more preferable. On the other hand, the upper limit of the binder content is preferably 20% by mass, and more preferably 15% by mass. By setting the binder content within the above range, the negative electrode active material can be stably held.

  As a minimum of average thickness of negative electrode active material layer 11, 10 micrometers is preferred and 20 micrometers is more preferred. On the other hand, the upper limit of the average thickness of the negative electrode active material layer 11 is preferably 100 μm, and more preferably 80 μm. By making the average thickness of the negative electrode active material layer 11 equal to or more than the lower limit, the negative electrode reaction can be sufficiently activated. Further, by setting the average thickness of the negative electrode active material layer 11 to be equal to or less than the above upper limit, the energy density of the laminated electrode body 1 and, in turn, the power storage element can be increased.

  The separator 5 is interposed between the positive electrode plate 3 and the negative electrode plate 4 to prevent the positive electrode plate 3 and the negative electrode plate 4 from coming into direct contact with each other. Charges can be transferred to and from the negative electrode plate 4 via ions.

  As shown in detail in FIG. 5, the separator 5 includes a sheet-like porous resin layer 13, an oxidation-resistant layer 14 laminated on at least the surface of the porous resin layer 13 facing the positive electrode plate 3, and the porous resin layer 13. It has a pair of adhesive layers 15 that are intermittently formed on both surfaces of the laminate of the resin layer 13 and the oxidation-resistant layer 14 and directly face (contact) the positive electrode plate 3 or the negative electrode plate 4.

  The porous resin layer 13 of the separator 5 is a layer mainly holding an electrolytic solution, and is formed from a porous resin film.

  Examples of the main component of the porous resin layer 13 include polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, polyolefin derivatives such as chlorinated polyethylene, ethylene, and the like. -Polyolefin such as propylene copolymer, polyester such as polyethylene terephthalate and copolymerized polyester, and the like can be employed. Among these, as the main component of the porous resin layer 13, polyethylene and polypropylene excellent in electrolytic solution resistance and durability are preferably used. The “main component” means a component having the largest mass content.

  As a minimum of average thickness of porous resin layer 13, 5 micrometers is preferred and 10 micrometers is more preferred. On the other hand, the upper limit of the average thickness of the porous resin layer 13 is preferably 30 μm, and more preferably 20 μm. By making the average thickness of the porous resin layer 13 equal to or more than the lower limit, the porous resin layer 13 can be prevented from breaking when the separators 5 are bonded to each other. Moreover, the energy density of the laminated electrode body 1 can be enlarged by making the average thickness of the porous resin layer 13 below the said upper limit.

  The oxidation-resistant layer 14 of the separator 5 is a layer provided to prevent the porous resin layer 13 from being oxidized and deteriorated, and includes a large number of inorganic particles and a binder that connects the inorganic particles.

  As the main component of the inorganic particles, for example, oxides such as alumina, silica, zirconia, titania, magnesia, ceria, yttria, zinc oxide, iron oxide, nitrides such as silicon nitride, titanium nitride, boron nitride, silicon carbide, carbonate Calcium, aluminum sulfate, aluminum hydroxide, potassium titanate, talc, kaolin clay, kaolinite, halloysite, pyrophyllite, montmorillonite, sericite, mica, amicite, bentonite, asbestos, zeolite, calcium silicate, magnesium silicate Etc. Among these, alumina, silica, and titania are particularly preferable as the main component of the inorganic particles of the oxidation resistant layer 14.

  The lower limit of the average particle size of the inorganic particles of the oxidation resistant layer 14 is preferably 1 nm, and more preferably 7 nm. On the other hand, the upper limit of the average particle diameter of the inorganic particles is preferably 5 μm and more preferably 1 μm. By setting the average particle diameter of the inorganic particles to the above lower limit or more, the ratio of the binder in the oxidation resistant layer 14 can be reduced, and the heat resistance of the oxidation resistant layer 14 can be increased. Moreover, the uniform oxidation-resistant layer 14 can be formed by making the average particle diameter of inorganic particles below the upper limit. The “average particle diameter” is a value measured according to JIS-670 using a transmission electron microscope (TEM) or a scanning electron microscope (SEM).

  Examples of the main component of the binder of the oxidation-resistant layer 14 include fluorine resins such as polyvinylidene fluoride and polytetrafluoroethylene, fluorine rubber such as vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene copolymer, and styrene-butadiene copolymer. And hydride thereof, acrylonitrile-butadiene copolymer and hydride thereof, acrylonitrile-butadiene-styrene copolymer and hydride thereof, methacrylate ester-acrylate copolymer, styrene-acrylate ester copolymer, Synthetic rubber such as acrylonitrile-acrylic acid ester copolymer, cellulose derivatives such as carboxymethylcellulose, hydroxyethylcellulose, ammonium salt of carboxymethylcellulose, polyetherimide, polyamideimide Polyimide such as polyamide and its precursor (polyamic acid etc.), ethylene-acrylic acid copolymer such as ethylene-ethyl acrylate copolymer, polyvinyl alcohol, polyvinyl butyral, polyvinyl pyrrolidone, polyvinyl acetate, polyurethane, polyphenylene ether, polysulfone , Polyethersulfone, polyphenylene sulfide, polyester and the like.

  The lower limit of the average thickness of the oxidation resistant layer 14 is preferably 2 μm, and more preferably 4 μm. On the other hand, the upper limit of the average thickness of the oxidation resistant layer 14 is preferably 6 μm and more preferably 5 μm. By making the average thickness of the oxidation-resistant layer 14 equal to or more than the lower limit, the oxidation-resistant layer 14 can be prevented from breaking when the separator 5 is bonded and fixed. Further, by making the average thickness of the oxidation resistant layer 14 equal to or less than the above upper limit, the thickness of the separator 5 is suppressed from becoming unnecessarily large, and the energy density of the laminated electrode body 1 and thus the power storage element is increased. Can do.

  The adhesive layer 15 of the separator 5 is a layer that adheres the separator 5 to the positive electrode plate 3 and the negative electrode plate 4 while having ion conductivity so as to enable an electrode reaction in the positive electrode plate 3 and the negative electrode plate 4. Specifically, the adhesive layer 15 is preferably a layer that develops adhesiveness by heating. The temperature exceeds room temperature, for example, a temperature of 60 ° C. or higher and the shutdown temperature of the separator 5 (the porous resin layer 13 melts). The adhesiveness can be exhibited when exposed to a temperature less than (temperature) (the temperature at which the adhesiveness is exhibited is 60 ° C. or more and less than the shutdown temperature of the separator 5). By configuring the adhesive layer 15 to exhibit adhesiveness in such a temperature range, the adhesive layer 15 does not exhibit adhesiveness at room temperature, so the handling of the subunit S is facilitated, and other components are damaged. When the adhesive layer 15 exhibits adhesiveness by heating to such a degree that it does not receive, the electrode unit U and thus the laminated electrode body 1 can be efficiently formed by being easily joined to other subunits S.

  As shown in FIG. 4, the adhesive layer 15 is arranged by patterning so as to leave an adhesive non-existing region E continuous from the outer edge of the separator 5 in a plan view of the separator 5. By patterning the adhesive layer 15 so that the separator 5 has the adhesive non-existing region E, the electrolyte solution can be quickly applied to the entire porous resin layer 13 through the adhesive non-existing region E during the production of the power storage element. Can be impregnated.

  The shape of the adhesive layer 15 in the plan view of the separator 5 may be, for example, a dot or a stripe, but is preferably a plurality of wavy line patterns W arranged in parallel to each other. By forming the adhesive layer 15 as a plurality of wavy line patterns W, the adhesive 5 is dispersed and arranged throughout the separator 5 while leaving the continuous adhesive non-existing region E, and the separator 5 is placed on the positive electrode plate 3 or the negative electrode It is possible to adhere to the plate 4 uniformly and firmly.

  The lower limit of the average amplitude of the wavy line pattern W is preferably 1.0 times the average interval (average width of the adhesive non-existing region E) of the wavy line pattern W, and more preferably 1.2 times. On the other hand, the upper limit of the average amplitude of the wavy pattern W is preferably 5 times the average interval of the wavy pattern W, and more preferably 4 times. By setting the average amplitude of the wavy line pattern W to be equal to or higher than the lower limit, the cutting line always crosses the wavy line pattern W when the separator 5 is cut in a straight line. An adhesive non-existing region E is formed on all outer edges of the side and a wavy line pattern W (adhesive) is arranged. For this reason, the introduction of the electrolyte solution through the adhesive non-existing region E can be promoted, and the outer edges of the separators 5 facing each other with the positive electrode plate 3 or the negative electrode plate 4 sandwiched by the wavy line pattern W are adhered to each other. In addition, it is possible to prevent foreign matter from entering the outer edge portion of the positive electrode plate 3 or the negative electrode plate 4 to cause electrodeposition.

  The lower limit of the average width of the wavy line pattern W is preferably 0.2 times the average interval of the wavy line pattern W, and more preferably 0.5 times. On the other hand, the upper limit of the average width of the wavy line pattern W is preferably 5 times the average interval of the wavy line pattern W, and more preferably 3 times. By setting the average width of the wavy line pattern W to be equal to or more than the lower limit, the adhesive layer 15 can exhibit a sufficient adhesive force. Moreover, by making the average width of the wavy line pattern W equal to or less than the above upper limit, it is possible to facilitate the impregnation of the electrolytic solution into the portion of the porous resin layer 13 covered with the adhesive layer 15.

  As a specific lower limit of the average width of the wavy line pattern W, 0.5 mm is preferable and 1 mm is more preferable. On the other hand, the upper limit of the average width of the wavy line pattern W is preferably 5 mm, and more preferably 3 mm. By setting the average width of the wavy line pattern W to be equal to or greater than the lower limit, the adhesive force of the adhesive layer 15 can be sufficiently increased and the adhesive layer 15 can be easily formed. Moreover, by making the average width of the wavy line pattern W equal to or less than the above upper limit, it is possible to facilitate the impregnation of the electrolytic solution into the portion of the porous resin layer 13 covered with the adhesive layer 15.

  The adhesive layer 15 can be formed from a mixed material containing particles exhibiting ionic conductivity and a binder. Specifically, the adhesive layer 15 may be formed of a material including solid electrolyte particles that contain an electrolyte solution and ensure ion conductivity, and a binder that exhibits adhesiveness by heating, ultrasonic vibration, or the like. it can. The adhesive layer 15 preferably has continuous pores so that liquid and gas can pass through.

  The lower limit of the average thickness of the adhesive layer 15 is preferably 0.1 μm, more preferably 0.2 μm, and even more preferably 0.4 μm. On the other hand, the upper limit of the average thickness of the adhesive layer 15 is preferably 5 μm, more preferably 3 μm, and even more preferably 1.2 μm. Sufficient adhesion can be obtained by setting the average thickness of the adhesive layer 15 to the lower limit or more. Moreover, sufficient ion conductivity can be obtained by making the average thickness of the adhesive layer 15 not more than the above upper limit.

  Examples of the material of the solid electrolyte particles of the adhesive layer 15 include inorganic solid electrolytes, genuine solid polymer electrolytes, and polymer gel electrolytes. Among them, the ion conductivity can be increased. A polymer gel electrolyte solution that is homogeneous and easily adjusts the particle diameter is particularly preferably used.

  The polymer gel electrolyte is one that is made easy to handle by gelling the electrolyte with a polymer. Examples of the polymer that gels the electrolytic solution include vinylidene fluoride-hexafluoropropylene copolymer, polymethylmethacrylic acid, polyacrylonitrile, and the like.

As the electrolytic solution of the polymer gel electrolytic solution, an organic electrolytic solution in which a supporting electrolytic solution 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 _{LiPF 6, LiAsF 6, LiBF 4} , LiSbF 6, LiAlCl 4, LiClO 4, CF 3 SO 3 Li, C 4 F 9 SO 3 Li, CF 3 COOLi, (CF ₃ CO) ₂ NLi, (CF ₃ SO ₂ ) ₂ NLi, (C ₂ F ₅ SO ₂ ) NLi, and the like. Among these, LiPF ₆ , LiClO ₄ , and CF ₃ SO ₃ Li that are easily soluble in an organic solvent and exhibit a high degree of dissociation are particularly preferable.

  The organic solvent used in the electrolytic solution is not particularly limited as long as it can dissolve the supporting electrolytic solution. For example, carbonates such as dimethyl carbonate, ethylene carbonate, diethyl carbonate, propylene carbonate, butylene carbonate, and methyl ethyl carbonate, for example, Esters such as γ-butyrolactone and methyl formate, ethers such as 1,2-dimethoxyethane and tetrahydrofuran, and sulfur-containing compounds such as sulfolane and dimethyl sulfoxide can be used alone or in combination. Among these, carbonates having a high dielectric constant and a wide stable potential region are particularly preferably used.

  As a minimum of the density | concentration of the support electrolyte solution in electrolyte solution, 1 mass% is preferable and 5 mass% is more preferable. On the other hand, as an upper limit of the density | concentration of the support electrolyte solution in electrolyte solution, 30 mass% is preferable and 20 mass% is more preferable. By setting the concentration of the supporting electrolyte in the electrolyte within the above range, relatively high ion conductivity can be obtained.

  The lower limit of the average particle diameter of the solid electrolyte particles is preferably 0.1 μm, and more preferably 0.2 μm. On the other hand, the upper limit of the average particle diameter of the solid electrolyte solution particles is preferably 2 μm, and more preferably 1 μm. By setting the average particle diameter of the solid electrolyte solution particles to be equal to or larger than the lower limit, the solid electrolyte solution particles can be brought into contact with each other to easily impart ion conductivity to the adhesive layer 15. Moreover, it becomes easy to form the contact bonding layer 15 in uniform film shape by making the average particle diameter of solid electrolyte solution particle | grains below the said upper limit.

  The shape of the solid electrolyte solution particles is preferably a shape having a small sphericity such as a rod shape, a cone shape, or a plate shape so that the contact between the solid electrolyte solution particles can be promoted to increase the ion conductivity.

  The binder of the adhesive layer 15 is not particularly limited as long as it has adhesiveness to the solid electrolyte solution particles and the positive electrode active material layer 8, but the positive electrode active material layer 8 is heated by heating at a relatively low temperature. An adhesive resin, that is, a polymer material having a relatively low glass transition point and exhibiting adhesiveness is preferably used.

  As a minimum of the glass transition point of a binder, -50 degreeC is preferable and -45 degreeC is more preferable. On the other hand, as an upper limit of the glass transition point of a binder, 50 degreeC is preferable and 45 degreeC is more preferable. By setting the glass transition point of the binder to the lower limit or more, the strength of the adhesive layer 15 can be ensured. Further, by setting the glass transition point of the binder to the upper limit or less, the separator 5 is opposed to the positive electrode plate 3 or the negative electrode plate 4 and the positive electrode plate 3 or the negative electrode plate 4 at a temperature at which the porous resin layer 13 is not damaged. 5 can be glued to the outer edge.

Examples of the main component of the binder include an acrylic polymer. As the acrylic polymer, a nitrile group-containing acrylic polymer containing a monomer unit having a nitrile group and a (meth) acrylic acid ester monomer unit is suitably used. Here, the monomer unit having a nitrile group is a structural unit obtained by polymerizing acrylonitrile, methacrylonitrile, or the like, for example, and the (meth) acrylic acid ester monomer unit is CH ₂ ═CR ¹ − It is a monomer unit derived from a compound represented by COOR ² (wherein R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group or a cycloalkyl group). A nitrile group-containing acrylic polymer is an ethylenically unsaturated compound formed by polymerizing an ethylenically unsaturated acid monomer in addition to a monomer unit having a nitrile group and a (meth) acrylic acid ester monomer unit. An acid monomer unit may be included. The nitrile group-containing acrylic polymer may be cross-linked.

  The lower limit of the ratio of the solid electrolyte particles in the adhesive layer 15 is preferably 70% by mass, and more preferably 80% by mass. On the other hand, the upper limit of the ratio of the solid electrolyte particles in the adhesive layer 15 is preferably 95% by mass, and more preferably 90% by mass. By setting the ratio of the solid electrolyte particles in the adhesive layer 15 to be equal to or higher than the lower limit, sufficient ion conductivity can be imparted to the adhesive layer 15. In addition, by setting the ratio of the solid electrolyte particles in the adhesive layer 15 to be equal to or less than the above upper limit, the adhesive ratio can be sufficiently imparted to the adhesive layer 15 with the binder ratio being relatively constant.

  As a method for arranging the adhesive layer 15 on the surface of the oxidation resistant layer 14 by patterning, for example, a printing technique such as gravure printing can be used. The wavy pattern W of the adhesive layer 15 is preferably formed in an endless shape extending in the circumferential direction of the gravure roll so as not to generate an axial force (thrust) of the gravure roll due to the viscosity of the adhesive during printing.

  The electrode unit U of the laminated electrode body 1 is formed by laminating a plurality of subunits S and bonding together the outer peripheral portions of the separator 5 protruding outside the positive electrode plate 3 and the negative electrode plate 4 when viewed from the lamination direction. can do.

  In the electrode unit U, the positive electrode plate 3 is adhesively fixed to the separators 5 on both sides, but the negative electrode plate 4 is adhesively fixed only to the separator 5 of the same subunit S, It is not glued and fixed.

  In the electrode unit U, it is preferable that a first bonding region 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 3 and the negative electrode plate 4 do not exist. The electrode unit U includes a second plate in which a plurality of separators 5 are partially bonded along a side edge where the positive electrode tab 9 and the negative electrode tab 12 of the positive electrode plate 3 and the negative electrode plate 4 are present and a side edge opposite to the side edge. An adhesive region may be formed. In this case, it is preferable that the first adhesive region and the second adhesive region are not formed in the vicinity of the corner of the separator 5. In order to bring the separators 5 into close contact with each other, each separator is bent along the side edges of the positive electrode plate 3 and the negative electrode plate 4 in the thickness direction of the positive electrode plate 3 and the negative electrode plate 4. Since bending in different directions interferes, bonding at this portion may cause an excessive load and damage the separator 5.

  The number of subunits S that the electrode unit U has can be, for example, 5 or more and 15 or less. By setting the number of stacked subunits S within this range, the distance between the outer separators 5 does not become too large, thereby protruding from the ends of the positive electrode plate 3 and the negative electrode plate 4 of each subunit S. Even if the length of the separator 5 is reduced, the end portions of the separator 5 can be bundled and bonded together to integrate the plurality of subunits S, so that the amount of the separator 5 used can be reduced.

  The resin film 6 prevents misalignment between the electrode units U when the plurality of electrode units U are bonded to each other, and prevents the conductive case 2 and the negative electrode plate 4 described later from contacting each other.

  Examples of the main component of the resin film 6 include polypropylene, polyethylene, and polyethylene terephthalate. Among these, as the main component of the resin film 6, polypropylene having a good heat sealing property is particularly suitable.

  As a minimum of average thickness of resin film 6, 20 micrometers is preferred and 50 micrometers is more preferred. On the other hand, the upper limit of the average thickness of the resin film 6 is preferably 150 μm, and more preferably 100 μm. By setting the average thickness of the resin film 6 to be equal to or more than the above lower limit, it is possible to prevent the positional deviation during the production of the plurality of electrode units U and the negative electrode plate 4 and to protect the negative electrode plate 4 without breaking. In addition, by making the average thickness of the resin film 6 equal to or less than the above upper limit, the laminate of the plurality of electrode units U and the negative electrode plate 4 can be easily and tightly covered without gaps. Thus, the effect of preventing the positional deviation of 4 can be ensured, and the energy density of the laminated electrode body 1 can be improved.

  The case 2 is a sealed container that houses the laminated electrode body 1 and in which an electrolytic solution is enclosed.

  The material of the case 2 may be, for example, a resin or the like as long as it has a sealing property that can enclose an electrolytic solution and a strength that can protect the laminated electrode body 1, but a metal is preferably used. In other words, the case 2 may be a flexible bag formed from, for example, a laminate film, but it is preferable to use a rigid metal case that can protect the laminated electrode body 1 more reliably.

  The case 2 can be configured to include a bottomed square cylindrical case body 16 and a plate-like lid body 17 that seals the opening of the case body 16. The lid 17 is provided with a positive external terminal 18 that is electrically connected to the positive electrode tab 9 of the positive electrode plate 3 and a negative external terminal 19 that is electrically connected to the negative electrode tab 12 of the negative electrode plate 4. Is done. Specifically, the positive external terminal 18 and the negative external terminal 19 are provided so as to penetrate the lid body 17.

  In addition, the storage element is attached to the positive electrode external terminal 18 and the negative electrode external terminal 19 inside the case 2, and includes the positive electrode connection member 20 and the negative electrode connection member 21 to which the positive electrode tab 9 and the negative electrode tab 12 of the laminated electrode body 1 are connected. Further, it may be provided.

  As the electrolytic solution sealed together with the laminated electrode body 1 in the case 2, a known electrolytic solution that is usually used for the electric storage element can be used. For example, cyclic carbonate such as ethylene carbonate, propylene carbonate, butylene carbonate, diethyl carbonate, dimethyl A solution in which lithium hexafluorophosphate or the like is dissolved in a solvent containing a chain carbonate such as carbonate or ethyl methyl carbonate can be used.

  Although the said electrical storage element is not specifically limited, The process (laminated electrode body formation process) of forming the laminated electrode body 1, the process of accommodating the laminated electrode body 1 in the case 2 (laminated electrode body accommodation process), And a step of filling an electrolyte solution (electrolyte solution filling step).

  The stacked electrode body forming step includes a step of forming the subunit S (subunit forming step), a step of forming the electrode unit U (electrode unit forming step), and a step of stacking a plurality of electrode units U (electrode unit stacking step). ), A step of disposing one negative electrode plate 4 on the separator 5 disposed in the outermost layer (negative electrode plate disposing step), and a step of heating and pressurizing in a state where the plurality of electrode units U and the negative electrode plates 4 are laminated. (Electrode body heating and pressurizing step). Further, the laminated electrode body forming step further includes a step of covering the outer periphery of the laminated body of the plurality of electrode units U and the negative electrode plate 4 with the resin film 6 (resin film wrapping step) before the electrode body heating and pressing step. It is more preferable.

  In the subunit forming step, one positive electrode plate 3 is disposed between two separators 5 and one negative electrode plate 4 is disposed on one separator 5 of the two separators 5 (arrangement). Step), one negative electrode plate 4, one of the two separators 5, one positive electrode plate 3 and the other of the two separators 5 are heated and pressurized in a state of being laminated in this order (unit heating) Pressure step) and a step (cutting step) of cutting the two separators 5 so that both side edges of the two separators 5 protrude from the side edges of the positive electrode plate 3 and the negative electrode plate 4, respectively.

  The subunit forming step may be performed using the separator 5 that has been cut in advance in the size of the subunit S by performing the cutting step first, but continuously using two long sheet-like separator base materials. Subunit S can be manufactured continuously and efficiently by performing the cutting step after performing the placement step and the unit heating and pressing step.

  More specifically, in the placement step, two separator base materials are continuously supplied and transported in the longitudinal direction, and the positive electrode is cut to the dimensions of the final product between the two separator base materials in the transported state. The plates 3 are sequentially inserted at equal intervals (a pitch equal to the width of the subunit S), and the negative plates 4 cut to the dimensions of the final product are sequentially arranged on the outer side of one separator base material so as to face the positive plate 3. To do.

  In the unit heating and pressing step, this long laminate is heated and pressurized while being continuously conveyed. Heating and pressurization may be performed simultaneously. Alternatively, the laminate may be pressed after heating and before the temperature of the adhesive layer 15 of the separator 5 drops to a temperature at which the adhesive strength is lost.

  Continuous conveyance of the separator base material, the laminate of the positive electrode plate 3 and the negative electrode plate 4 can be performed using, for example, a conveyance belt having releasability.

  The laminated body in the unit heating and pressing step can be heated using, for example, a plate heater disposed so as to sandwich the laminated body. Moreover, the pressurization in the unit heating and pressurizing step can be performed using, for example, a pair of pressure rollers that sandwich the laminate. Alternatively, heating and pressurization may be performed simultaneously using a pair of heating rollers that generate heat with the laminate interposed therebetween.

  The heating temperature in the unit heating and pressing step is set to be equal to or higher than the temperature at which the adhesive layer 15 of the separator 5 develops adhesive force and lower than the shutdown temperature of the porous resin layer 13, for example, 80 ° C. or higher and 120 ° C. or lower. it can.

  The pressurizing pressure in the unit heating and pressurizing step can be set to, for example, 0.1 N / cm or more and 10.0 N / cm or less by a load per unit length of the pressing roller.

  In the cutting step, the subunits S are sequentially separated by cutting the separator base material with a cutter to form a separator 5 having a predetermined length.

  In the electrode unit formation step, a plurality of subunits S are stacked (subunit stacking step), and the separators 5 protruding from the ends of the positive electrode plate 3 and the negative electrode plate 4 of each of the stacked subunits S are bonded together. It is preferable to have a process (adhesion process). The laminated electrode body forming step includes a step of trimming the outer portions of the plurality of bonded separators 5 (trimming step), and the bonding portions of the plurality of separators 5 are bent along the side edges of the positive electrode plate 3 and the negative electrode plate 4. You may further have a process (bending process).

  In the subunit stacking step, a plurality of subunits S are oriented and stacked in the same direction. Thereby, the some positive electrode plate 3 and the some negative electrode plate 4 are arrange | positioned alternately via the separator 5, and the laminated body by which the separator 5 is arrange | positioned further outside the outermost positive electrode plate 3 is formed.

  The plurality of subunits S are stacked by, for example, using a guide or the like that contacts the four outer edges of the separator 5, and sequentially inserting the subunits S formed in the subunit forming step into the guides. By stacking S, it can be performed relatively quickly and accurately.

  In the bonding step, the end portions of all the separators 5 are bundled and bonded so as to be in close contact with each other. The end of the separator 5 can be bonded using a heating member or an ultrasonic vibrator.

  In the trimming step, a portion protruding outside the adhesion region of the separator 5 is cut off. The separator 5 is designed to have a minimum size capable of forming an adhesion region. When the separators 5 are bundled so as to be in close contact with each other in the adhesion process, the end of the separator 5 depends on the thickness of the positive electrode plate 3 and the negative electrode plate 4. Since the portions are displaced stepwise, the separator 5 protrudes outside the bonding region formed in the portion where all the separators 5 are stacked. Therefore, in this trimming step, a portion protruding stepwise outside the adhesion region is mainly cut off. Thereby, when the laminated electrode body 1 is formed, the dead space occupied by the separator 5 outside the adhesion region can be reduced, and the energy density of the laminated electrode body 1 can be increased.

  In the bending step, the portions of the separator 5 that protrude from the positive electrode plate 3 and the negative electrode plate 4 are bent along the side edges of the positive electrode plate 3 and the negative electrode plate 4. Thereby, when the laminated electrode body 1 is formed, the dead space occupied by the portions protruding from the positive electrode plate 3 and the negative electrode plate 4 of the separator 5 can be reduced, and the energy density of the laminated electrode body 1 can be increased.

  In the electrode unit lamination step, the plurality of electrode units U are oriented and laminated in the same direction. That is, between two adjacent electrode units U, the separator 5 of the other electrode unit U abuts on the negative electrode plate 4 of one electrode unit U. Thereby, a laminated body in which a plurality of positive electrode plates 3 and negative electrode plates 4 are laminated via the separator 5 is formed.

  In the negative electrode plate arranging step, a further negative electrode plate 4 is laminated on the outer side of the separator 5 arranged on the outermost layer, whereby the negative electrode plate 4 is arranged on both outer sides, and the plurality of positive electrode plates 3 and negative electrode plates 4 are separated from each other. 5 to form a laminated body alternately laminated.

  In the resin film wrapping step, a plurality of electrode units U and a laminate of one additional negative electrode plate 4 are covered with the resin film 6, so that the plurality of electrode units U and negative electrode plates 4 are formed in the next electrode body heating and pressing step. Hold it so that it is not misaligned.

  As described above, the resin film 6 prevents the displacement of the separator 5, the positive electrode plate 3, and the negative electrode plate 4 in the electrode body heating and pressing step, thereby reducing the margin for the displacement of the positive electrode plate 3 and the negative electrode plate 4. The opposing area of the positive electrode plate 3 and the negative electrode plate 4 can be increased, and the energy density of the laminated electrode body 1 can be further improved.

  In the electrode body heating and pressing step, the outermost electrodes between adjacent subunits S and the outermost electrodes are preferably heated and pressed by heating and pressing a laminated body of a plurality of electrode units U and one negative electrode plate 4 covered with the resin film 6. The separator 5 outside the unit U and the negative electrode plate 4 are joined. Thereby, the laminated electrode body 1 in which all the separators 5, the positive electrode plate 3, and the negative electrode plate 4 are bonded and fixed to each other is obtained.

  In the laminated electrode body housing step, the positive electrode tab 9 and the negative electrode tab 12 are connected to the positive electrode connecting member 20 and the negative electrode connecting member 21, respectively, and then the laminated electrode body 1 is inserted into the case body 16 and the lid body 17 The opening of the main body 16 is sealed.

  As a method for connecting the positive electrode tab 9 and the negative electrode tab 12 to the positive electrode connecting member 20 and the negative electrode connecting member 21, for example, ultrasonic welding, laser welding, caulking, or the like can be employed.

  In the electrolytic solution filling step, the electrolytic solution is injected into the case 2. For this reason, it is preferable that the case 2 be formed with a sealable inlet.

  The said embodiment does not limit the structure of this invention. Therefore, in the above-described embodiment, components of each part of the above-described embodiment can be omitted, replaced, or added based on the description and common general knowledge of the present specification, and they are all interpreted as belonging to the scope of the present invention. Should.

  The laminated electrode body may be one in which the separators are not bonded to each other on the outside of the positive electrode plate or the negative electrode plate, and the separators are welded together, that is, the oxidation-resistant layer is destroyed and the porous resin layers are welded together. May be. Moreover, the said laminated electrode body may laminate | stack the some positive electrode plate, the negative electrode plate, and the separator, without forming an electrode unit or a subunit.

  In the laminated electrode body, the separator may not have an oxidation resistant layer.

  The power storage element may be one in which the positive electrode external terminal is omitted, the positive electrode tab is connected to the case (for example, a cover plate), and the case serves as the external terminal.

  The laminated electrode body and the electricity storage device according to the present invention are particularly preferably used as a power source for vehicles such as electric vehicles and plug-in hybrid electric vehicles (PHEV). The power storage device according to the present invention includes a power storage system (large-scale power storage system, small-scale power storage system for home use), a distributed power system combined with natural energy such as sunlight and wind power, a power supply system for railways, and an automated guided vehicle. It can also be suitably used for industrial applications such as a power supply system for (AGV).

DESCRIPTION OF SYMBOLS 1 Laminated electrode body 2 Case 3 Positive electrode plate 4 Negative electrode plate 5 Separator 6 Resin film 7 Positive electrode collector 8 Positive electrode active material layer 9 Positive electrode tab 10 Negative electrode collector 11 Negative electrode active material layer 12 Negative electrode tab 13 Porous resin layer 14 Acid resistance Layer 15 Adhesive layer 16 Case body 17 Lid 18 Positive external terminal 19 Negative external terminal 20 Positive connection member 21 Negative connection member E Adhesive-free area S Subunit U Electrode unit W Wavy line pattern

Claims (6)

A positive electrode plate, a negative electrode plate laminated on the positive electrode plate, and a separator sandwiched between the positive electrode plate and the negative electrode plate,
The separator has a porous resin layer and an adhesive layer that is intermittently formed and directly faces the positive electrode plate or the negative electrode plate,
The laminated electrode body, wherein the adhesive layer is disposed so as to leave an adhesive non-existing region continuous from an outer edge of the separator in a plan view of the separator. The laminated electrode body according to claim 1, wherein a shape of the adhesive layer in a plan view of the separator is a plurality of wavy line patterns arranged in parallel to each other. The multilayer electrode body according to claim 2, wherein an average amplitude of the wavy line pattern is equal to or greater than an average interval of the wavy line patterns. The laminated electrode body according to claim 2 or 3, wherein an average width of the wavy line pattern is 0.2 to 5 times an average interval of the wavy line pattern. The laminated electrode body according to claim 2, 3 or 4, wherein an average width of the wavy line pattern is 0.5 mm or more and 5 mm or less. The laminated electrode body according to any one of claims 1 to 5,
And a case for housing the laminated electrode body.

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