JP2010153224A - Electrode and manufacturing method for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrode with reduced contact resistance between a collector and an active material layer which is, especially, effective in a bipolar lithium-ion secondary battery, as well as, to provide a manufacturing method for the electrode. <P>SOLUTION: The electrode is provided with the collector constituted of polymeric materials etc. including conductive polymer or a conductive filler, as well as, the active material layer formed on the collector and containing the active material and a binder. As the polymer of the collector and the binder in the electrode are both dissolved in a solvent, the electrode has the active material layer adhered on the surface of the collector. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electrode and a manufacturing method thereof.

  In recent years, reduction of carbon dioxide emissions has been strongly desired for environmental protection. In the automobile industry, there are high expectations for reducing carbon dioxide emissions by introducing electric vehicles (EVs) and hybrid electric vehicles (HEVs), and we are eager to develop secondary batteries for motor drives that hold the key to their practical application. Has been done. As a secondary battery, attention is focused on a lithium ion secondary battery that can achieve a high energy density and a high output density.

  In general, a lithium ion secondary battery is configured by applying a positive electrode or a negative electrode active material or the like to a current collector using a binder.

In such a lithium ion secondary battery, conventionally, a metal foil has been used as a current collector. In recent years, a conductive current collector containing a resin has been used instead of a metal foil for the purpose of reducing the weight of a battery (for example, see Patent Document 1). A conductive current collector containing such a resin is lighter than a metal foil, and an improvement in energy density per weight is expected.
JP-A 61-285664

  The production of the electrode is usually performed by applying an active material slurry containing an active material, a binder and a solvent on a current collector and drying the solvent. However, when the active material slurry is applied to a conductive current collector containing a resin by a normal application method, the active material slurry is repelled by the current collector, so that the active material slurry can be applied well on the current collector. It was difficult. Further, there is a problem that the contact resistance between the current collector and the active material layer of the obtained electrode is increased.

  Accordingly, an object of the present invention is to reduce the contact resistance between the current collector and the active material layer.

  As a result of intensive studies in view of the above problems, the present inventors have dissolved the resin layer surface of the current collector including the resin layer in a solvent, so that the resin layer and the active material layer in the current collector are separated. The present inventors have found that a bonded electrode can solve the above-mentioned problems and completed the present application.

  The electrode of the present invention reduces the contact resistance between the current collector and the active material layer by bonding the resin layer and the active material layer and improving the adhesion between the resin layer and the active material layer in the current collector. To do.

  First, a bipolar lithium ion secondary battery electrode which is a preferred embodiment of the present invention will be described, but is not limited to the following embodiment. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. In addition, the dimensional ratios in the drawings are exaggerated for convenience of explanation, and may be different from the actual ratios.

  FIG. 1 is a schematic view showing a bipolar lithium ion secondary battery electrode which is a preferred embodiment (hereinafter also referred to as a first embodiment) of the present invention. The bipolar electrode 1 has a structure in which a positive electrode (positive electrode active material layer) 13 is provided on one surface of a current collector 11 and a negative electrode (negative electrode active material layer) 15 is provided on the other surface. In 1st embodiment, a collector is comprised from the resin layer which has electroconductivity. The current collector 11 is bonded to the positive electrode active material layer and the negative electrode active material layer by being dissolved by a solvent used for the active material slurry. The polymer material in the current collector is dissolved in the solvent contained in the active material slurry, and the present invention uses a current collector containing the polymer material dissolved in the solvent contained in the active material slurry. It can be said that it is a feature. The resistance between the active material layer and the current collector can be lowered by bonding the current collector to the active material layer.

  In addition, for example, in a lithium ion secondary battery, during the charging and discharging processes, the positive and negative electrode active material layers expand and contract due to insertion and extraction of lithium ions into and out of the positive and negative electrode active materials, and current collection occurs due to the generated stress. There was a problem that the body and the active material layer were separated. Since the peel strength is improved by bonding the current collector and the active material layer as in this embodiment, such a problem can be solved.

  The adhesion between the current collector and the active material layer of the present embodiment is achieved by the polymer material contained in the current collector (resin layer) being dissolved by the solvent and then solidified by the volatilization of the solvent. .

  The current collector of a normal battery that is not a bipolar type transfers charge through a tab attached to the end of the current collector, and the current collector collects the charge generated on the negative electrode side into the tab or supplies it from the tab. A function of transmitting the generated electric charge to the positive electrode side. Therefore, the current collector needs to have a low electric resistance in the horizontal direction (surface direction) in which charges move, and a metal foil having a certain thickness is used to reduce the electric resistance in the horizontal direction. On the other hand, in a current collector of a bipolar battery, unlike a normal battery, the charge generated on the negative electrode side is directly supplied to the positive electrode existing on the opposite side of the current collector. For this reason, the current flows in the stacking direction of the components of the bipolar battery, and does not need to flow in the horizontal direction. Therefore, in order to reduce the electrical resistance in the horizontal direction, a conventional metal foil is not necessarily used as the current collector, and the electrode of the present invention having a resin current collector can be suitably used. Further, by applying a current collector including a conductive resin layer to the bipolar electrode, preferably a current collector made of a conductive resin layer, the weight of the battery can be reduced. By reducing the weight of the electrode, it is advantageous in that the output density can be increased when applied to a battery. Bipolar batteries have an energy density that is more than twice that of conventional batteries. The energy released during anomalies is large and the temperature tends to rise excessively. Compared with metal foil current collectors. And when a resin layer electrical power collector is applied, such a temperature rise is suppressed.

  For the above reasons, the electrode of the present invention is preferably a bipolar electrode. When the electrode of the present invention is a bipolar electrode, the volume resistivity of the electrode is preferably in the range of 0.1 to 1.0 mΩ · cm. If the volume resistivity is in such a range, it is suitable as a current collector for a bipolar battery. Here, the volume resistivity is calculated by cutting an electrode into a certain size, measuring the absolute value of resistance, multiplying that value by the area, and dividing the thickness.

  In FIG. 1, both the positive electrode and the negative electrode active material layer are bonded to the current collector by dissolution with a solvent, but at least one of the positive electrode active material layer or the negative electrode active material layer is a resin layer. The bonded form is also within the scope of the present invention. Preferably, both the positive electrode active material layer and the negative electrode active material layer are bonded.

  Next, each element constituting the electrode will be described.

(Current collector)
The current collector 2 includes at least one resin layer having conductivity. In order for the resin layer to adhere to the active material layer, the side in contact with the active material layer, that is, at least one of the outermost layers of the current collector becomes the resin layer. The current collector may include at least a resin layer, and specific examples include a current collector composed of one or more resin layers, a laminate of a resin layer and a metal foil, and the like. Preferably, from the viewpoint of weight reduction, the current collector is composed of one or more resin layers (a single resin layer or a laminate of two or more resin layers).

  The resin layer has conductivity and includes a polymer material. Specific forms in which the current collector has conductivity include 1) a form in which the polymer material is a conductive polymer, and 2) a form in which the resin layer includes a conductive filler.

  The conductive polymer is selected from materials that are conductive and have no conductivity with respect to ions used as charge transfer media. These conductive polymers are considered to be conductive because the conjugated polyene system forms an energy band. As a typical example, a polyene-based conductive polymer that has been put into practical use in an electrolytic capacitor or the like can be used. Specifically, polyaniline, polypyrrole, polythiophene, polyacetylene, polyparaphenylene, polyphenylene vinylene, polyacrylonitrile, polyoxadiazole, or a mixture thereof is preferable. Polyaniline, polypyrrole, polythiophene, and polyacetylene are more preferable from the viewpoint of electronic conductivity and stable use in the battery.

  The conductive filler is selected from materials that are conductive and have no conductivity with respect to the ions used as the charge transfer medium. The conductive filler is selected from materials that can withstand the applied positive electrode potential and negative electrode potential. Specific examples include aluminum particles, SUS particles, carbon particles such as graphite and carbon black, silver particles, gold particles, copper particles, and titanium particles, but are not limited thereto. These conductive fillers may be used alone or in combination of two or more. Moreover, these alloy particles may be used. The conductive filler is not limited to the above-described form, and carbon nanotubes or VGCF (vapor growth carbon fiber) may be used.

  As the conductive filler used on the positive electrode side, aluminum particles, SUS particles, gold particles and carbon particles are preferable from the viewpoint of conductivity, and carbon particles are more preferable. As the conductive filler used for the negative electrode, silver particles, gold particles, copper particles, titanium particles, SUS particles, and carbon particles are preferable from the viewpoint of conductivity, and carbon particles are more preferable. Carbon particles such as carbon black and graphite have a very wide potential window, are stable in a wide range with respect to both the positive electrode potential and the negative electrode potential, and are excellent in conductivity. Also, since the carbon particles are very light, the increase in mass is minimized. Furthermore, since carbon particles are often used as a conductive aid for electrodes, even if they come into contact with these conductive aids, the contact resistance is very low because of the same material. When carbon particles are used as the conductive filler, it is possible to reduce the compatibility of the electrolyte by applying a hydrophobic treatment to the surface of the carbon, making it difficult for the electrolyte to penetrate into the current collector holes. is there.

  Although the average particle diameter of an electroconductive filler is not specifically limited, Usually, they are 20 nm-30 micrometers. In the present specification, “particle diameter” means the maximum distance L among the distances between any two points on the contour line of the active material particles. As the value of “average particle diameter”, the average particle diameter of particles observed in several to several tens of fields using an observation means such as a scanning electron microscope (SEM) or a transmission electron microscope (TEM). The calculated value shall be adopted.

  When the resin layer includes a conductive filler, the polymer material forming the resin layer preferably includes a non-conductive polymer material that binds the conductive filler. By using a polymer material as the constituent material of the resin layer, the binding property of the conductive filler can be improved and the reliability of the battery can be improved. The polymer material is selected from materials that can withstand the applied positive electrode potential and negative electrode potential.

  Examples of non-conductive polymer materials include polyolefins such as polyethylene (PE) and polypropylene (PP); polyesters such as polyethylene terephthalate (PET) and polyethernitrile (PEN); polyimide (PI); polyamide (PA) Polyamideimide; Polyvinylidene fluoride (PVdF); Polytetrafluoroethylene (PTFE); Styrene butadiene rubber (SBR); Polyacrylonitrile (PAN); Polymethylacrylate (PMA); Polymethylmethacrylate (PMMA); PVC) and the like. These polymer materials may be used alone or in combination of two. These materials have a very wide potential window, are stable in a wide range with respect to both the positive electrode potential and the negative electrode potential, and can improve adhesion. More preferably, it is a polyvinylidene fluoride from the point of the meltability with respect to a solvent.

  The polymer material contained in the resin layer is preferably the same as the material constituting the binder contained in the active material layer described later. By using the same material, the interface between the binder and the resin layer in the active material layer is eliminated, the peel strength is further improved, and the resistance of the electrode is reduced.

  Note that the same material is sufficient if the same material is included. Preferably, the main component of the polymer material constituting the current collector and the main component of the polymer material included in the active material layer are the same. preferable. Here, the main component refers to a component that is 60% by mass or more in the polymer material, preferably 70% by mass or more, and more preferably 80% by mass or more.

  The ratio of the polymer material and the conductive filler in the resin layer is not particularly limited, but is preferably 2 to 40% by mass, more preferably 10 to 35% by mass with respect to the total of the polymer material and the conductive filler. % Conductive filler. By allowing a sufficient amount of the conductive filler to be present, sufficient conductivity in the resin layer can be secured.

  In addition to the conductive filler and the polymer material, the resin layer may contain other additives.

  The conductive filler contained in the resin layer preferably protrudes into the active material layer at the interface between the resin layer and the active material layer. Referring to FIG. 2, the conductive filler 5 included in the current collector 2 protrudes from the positive electrode active material layer 4 including the positive electrode active material 3. By projecting the conductive filler into the active material layer, the contact area is increased, and the contact resistance between the active material layer and the current collector is further reduced. In addition, in FIG. 3, although the electroconductive filler is described in the fiber form, it does not specifically limit about this in shape. In addition, as shown in FIG. 2, the conductive filler is not limited to the form protruding to the positive electrode active material layer, and any conductive filler protrudes from at least one of the positive electrode active material layer and the negative electrode active material layer. Good. Preferably, the conductive filler protrudes from both the positive electrode and the negative electrode active material layer.

  The thickness of the current collector is not particularly limited, but it is preferably as thin as possible to increase the output density of the battery. In the bipolar battery, the current collector present between the positive electrode and the negative electrode may have a high electric resistance in the direction parallel to the stacking direction, and thus the thickness of the current collector can be reduced. Specifically, the thickness of the current collector is preferably 100 μm or less, and preferably 0.1 to 80 μm or less.

(Active material layer)
[Positive electrode (positive electrode active material layer) and negative electrode (negative electrode active material layer)]
The active material layer 13 or 15 contains an active material, and further contains other additives as necessary.

The positive electrode active material layer 13 includes a positive electrode active material. As the positive electrode active material, for example, LiMn ₂ O ₄ , LiCoO ₂ , LiNiO ₂ , Li (Ni—Co—Mn) O _2, and lithium-such as those in which a part of these transition metals are substituted with other elements Examples include transition metal composite oxides, lithium-transition metal phosphate compounds, and lithium-transition metal sulfate compounds. In some cases, two or more positive electrode active materials may be used in combination. Preferably, a lithium-transition metal composite oxide is used as the positive electrode active material from the viewpoint of capacity and output characteristics. Of course, positive electrode active materials other than those described above may be used.

The negative electrode active material layer 15 includes a negative electrode active material. Examples of the negative electrode active material include carbon materials such as graphite, soft carbon, and hard carbon, lithium-transition metal composite oxides (for example, Li ₄ Ti ₅ O ₁₂ ), metal materials, lithium alloy negative electrode materials, and the like. . In some cases, two or more negative electrode active materials may be used in combination. Preferably, from the viewpoint of capacity and output characteristics, a carbon material or a lithium-transition metal composite oxide is used as the negative electrode active material. Of course, negative electrode active materials other than those described above may be used.

  The average particle diameter of each active material contained in each active material layer 13, 15 is not particularly limited, but is preferably 1 to 20 μm from the viewpoint of increasing the output.

  The positive electrode active material layer 13 and the negative electrode active material layer 15 include a binder.

  Although it does not specifically limit as a binder used for an active material layer, For example, the following materials are mentioned. Polyethylene, polypropylene, polyethylene terephthalate (PET), polyether nitrile (PEN), polyacrylonitrile, polyimide, polyamide, cellulose, carboxymethyl cellulose (CMC), ethylene-vinyl acetate copolymer, polyvinyl chloride, styrene-butadiene rubber (SBR) ), Isoprene rubber, butadiene rubber, ethylene / propylene rubber, ethylene / propylene / diene copolymer, styrene / butadiene / styrene block copolymer and hydrogenated product thereof, styrene / isoprene / styrene block copolymer and hydrogenated product thereof Thermoplastic polymers such as products, polyvinylidene fluoride (PVdF), polytetrafluoroethylene (PTFE), tetrafluoroethylene / hexafluoropropylene copolymer (FE) ), Tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), ethylene / tetrafluoroethylene copolymer (ETFE), polychlorotrifluoroethylene (PCTFE), ethylene / chlorotrifluoroethylene copolymer (ECTFE) , Fluororesin such as polyvinyl fluoride (PVF), vinylidene fluoride-hexafluoropropylene-based fluororubber (VDF-HFP-based fluororubber), vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene-based fluororubber (VDF-HFP-) TFE fluorine rubber), vinylidene fluoride-pentafluoropropylene fluorine rubber (VDF-PFP fluorine rubber), vinylidene fluoride-pentafluoropropylene-tetrafluoroethylene Fluoro rubber (VDF-PFP-TFE fluoro rubber), vinylidene fluoride-perfluoromethyl vinyl ether-tetrafluoroethylene fluoro rubber (VDF-PFMVE-TFE fluoro rubber), vinylidene fluoride-chlorotrifluoroethylene fluoro rubber Examples thereof include vinylidene fluoride-based fluororubber such as (VDF-CTFE-based fluororubber), an epoxy resin, and the like. Among these, polyvinylidene fluoride, polyimide, styrene / butadiene rubber, carboxymethyl cellulose, polypropylene, polytetrafluoroethylene, polyacrylonitrile, and polyamide are more preferable. These suitable binders are excellent in heat resistance, have a very wide potential window, are stable at both the positive electrode potential and the negative electrode potential, and can be used for the active material layer. These binders may be used alone or in combination of two.

  The amount of the binder contained in the active material layer is not particularly limited as long as it is an amount capable of binding the active material, but is preferably 0.5 to 15% by mass with respect to the active material layer. Yes, more preferably 1 to 10% by mass.

  Examples of other additives that can be included in the active material layer include a conductive additive, an electrolyte salt (lithium salt), and an ion conductive polymer.

  The conductive assistant refers to an additive that is blended in order to improve the conductivity of the positive electrode active material layer or the negative electrode active material layer. Examples of the conductive assistant include carbon materials such as carbon black such as acetylene black, graphite, and vapor grown carbon fiber. When the active material layer contains a conductive additive, an electronic network inside the active material layer is effectively formed, which can contribute to improvement of the output characteristics of the battery.

Examples of the electrolyte salt (lithium salt) include Li (C ₂ F ₅ SO ₂ ) ₂ N, LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , LiCF ₃ SO _{3 and the} like.

  Examples of the ion conductive polymer include polyethylene oxide (PEO) -based and polypropylene oxide (PPO) -based polymers.

  The compounding ratio of the components contained in the positive electrode active material layer and the negative electrode active material layer is not particularly limited. The mixing ratio can be adjusted by appropriately referring to known knowledge about the non-aqueous solvent secondary battery. The thickness of each active material layer is not particularly limited, and conventionally known knowledge about the battery can be appropriately referred to. For example, the thickness of each active material layer is about 2 to 100 μm.

  The bipolar lithium ion secondary battery electrode according to a preferred embodiment of the present invention has been described above, but the electrode of the present invention is not limited to the bipolar type. For example, you may apply to the positive electrode which has arrange | positioned the positive electrode active material layer on both surfaces of the electrical power collector, or the negative electrode which has arrange | positioned the negative electrode active material layer on both surfaces of the electrical power collector. As described above, the bipolar electrode has a remarkable effect of the present invention.

  In this electrode, since the resin layer and the active material layer are bonded by solvent dissolution, the peel strength between the resin layer and the active material layer is improved. Specifically, the peel strength between the resin layer and the active material layer is preferably 50 mN / mm or more. By setting the peeling strength to 50 mN / mm or more, peeling between the active material layer and the current collector can be suppressed even when charging and discharging are repeated. The peel strength is preferably as high as possible, but is usually about 200 mN / mm or less, and preferably 150 mN / mm or less. As the peel strength value, a value calculated by the method of an example described later is adopted.

(Method for manufacturing electrode)
A preferred method for producing an electrode of the present invention (hereinafter also referred to as a second embodiment) includes a step of mixing an active material, a binder and a solvent to obtain an active material slurry (hereinafter also referred to as a first step), and a conductive property. A step of applying the active material slurry onto a resin layer of a current collector including a resin layer (hereinafter also referred to as a second step), wherein the solvent is a polymer material contained in the resin layer. It is a solvent that dissolves.

  As described above, from the viewpoint of weight reduction, a current collector including a conductive resin layer is excellent. However, when an active material slurry is applied to the resin layer, the current collector and the solvent contained in the active material slurry are collected. Since the affinity with the electric body is low, the coated product sometimes repels. In addition, since the current collector contains a resin, it may be difficult to produce an electrode when a current collector including a conductive resin layer is used, such as a strong press cannot be applied. By using a solvent that dissolves the polymer material contained in the resin layer in the active material slurry used when forming the active material layer, the resin layer and the active material layer can be bonded together by a simple manufacturing method. In addition, the peel strength between the current collector and the active material layer can be improved.

  Hereinafter, each step will be described.

1. First step In this step, a desired active material, a binder, and other components as necessary (for example, a conductive assistant, an ion conductive polymer, a supporting salt (lithium salt), a polymerization initiator, a dispersant, etc.) An active material slurry is prepared by mixing in a solvent. Since the specific form of each component blended in the active material slurry is as described in the column of the configuration of the electrode of the present invention, detailed description is omitted here.

  The solvent of the active material slurry is appropriately selected according to the polymer material used for the resin layer. Preferably, the solvent is a solvent that dissolves the polymer material used for the resin layer. Here, the dissolution of the polymer material in the solvent takes into account the SP value difference between the polymer material and the solvent. In the present invention, dissolution is made when the difference in SP value between the polymer material and the solvent is 3 or less. The difference in SP value is preferably 1 or less. The SP value is a solubility parameter, and the smaller the difference between the SP value of the polymer material and the SP value of the solvent, the easier the solvent dissolves the polymer material. However, if the difference between the SP value of the polymer material and the solvent is too small, there may be holes in the polymer material during drying, so the difference in SP value is more preferably 0.2 or more. . SP value as used in the field of this invention means the solubility parameter calculated | required using the calculation formula of Fedors. According to Fedors' formula (R. F. Fedors. Polymer Engineering and Science, Vol. 14, p. 147, 1974), the solubility parameter is the square root of the sum of the molar cohesive energies of each atomic group divided by the volume. Thus, the polarity per unit volume is shown. The larger the solubility parameter, the higher the polarity.

  The solvent used in the slurry is not particularly limited, and conventionally known knowledge about electrode production can be appropriately referred to. Examples of solvents include N-methyl-2-pyrrolidone (NMP) (SP value; 11.2), dimethylformamide (SP value; 11.9), dimethylacetamide (SP value; 10.8), xylene, and the like. Can be used. These may be used alone or in combination of two or more.

  In addition, when the solvent or polymer material contained in the slurry is used in combination of two or more kinds, the SP value of each component is interpolated (averaged) according to the composition (mass ratio) to obtain the SP value. Is approximately obtained.

  Specific examples of the combination of such a polymer material and a solvent are as follows (hereinafter, polymer material and solvent in this order). Polyvinylidene fluoride, NMP; polyamide, NMP; styrene butadiene rubber, xylene.

  The solid content rate of the active material slurry (solid content ratio with respect to 100% by mass of the active material slurry) is preferably 40% by mass or less. By using a low-viscosity slurry, coating becomes easier as compared with a conventional high-viscosity slurry. According to a normal manufacturing process, even a low-viscosity slurry whose area increases after coating can be applied as a slurry by using a solvent that dissolves the polymer material. This is considered to be because the solvent contained in the slurry is absorbed by the resin layer surface. The lower limit of the solid content of the slurry is preferably 25% by mass or more and more preferably 30% by mass or more in consideration of the amount of active material. In particular, as will be described later, when a current collector having a somewhat high surface roughness is used, a lower viscosity slurry can be used. This is because the slurry can enter the irregularities on the surface of the resin layer. When such a current collector is used, the solid content of the slurry is preferably 20% by mass or more, and more preferably 25% by mass or more.

2. Second Step A current collector including a conductive resin layer can be produced by a conventionally known production method, preferably by using a spray method, a coating method, an extrusion method or the like. For example, there is a method of preparing a slurry containing a polymer material, and optionally a conductive filler and a solvent, and applying and curing the slurry. Alternatively, the current collector can also be produced by the following method. A polymer material, optionally a conductive filler, and, if necessary, an appropriate solvent are added and melt kneaded. Although the temperature at the time of kneading | mixing is suitably set with the resin used, it is about 200-280 degreeC normally. Specifically, for example, after pre-blending with a mixer such as an omni mixer, a method of extrusion kneading the obtained mixture can be employed. In this case, the kneader used for extrusion kneading is not particularly limited. For example, a conventionally known kneader such as an extruder such as a single screw extruder or a twin screw extruder or a pressure kneader is used. Can do.

  The surface roughness of the current collector on the side of the resin layer before applying the active material slurry is preferably 0.3 <Ra <5 μm and 3 <Rz <30 μm. When the surface roughness of the resin layer is in a range exceeding the lower limit, it is preferable because the slurry can enter the irregularities formed on the surface of the resin layer, and the slurry can be used even when the viscosity of the slurry is low. Setting the surface roughness to be less than the upper limit is preferable because the strength of the current collector is maintained, and it is not necessary to increase the thickness of the resin layer in order to maintain the strength. Ra represents the arithmetic average height defined by JIS B 0601 (2001), and Rz represents the ten-point average roughness defined by JIS B 0601 (2001). The method for adjusting the surface roughness of the resin layer within the above-mentioned preferable range is not particularly limited, and examples thereof include a method of processing a current collector with sandpaper; a blast method and the like.

  The application method in particular when apply | coating the said active material slurry on a resin layer is not restrict | limited, For example, means generally used, such as a self-propelled coater, a doctor blade method, a spray method, can be employ | adopted. Moreover, you may apply | coat an active material slurry on a resin layer by transcription | transfer.

  In the present invention, since the resin layer is dissolved by the solvent contained in the active material slurry, the active material slurry is less likely to be repelled by the resin layer as compared with the conventional manufacturing method.

  Note that the polymer material actually contained in the resin layer is dissolved in the solvent because the solvent contained in the active material layer (at room temperature) is contained in the resin layer by applying the active material slurry on the resin layer. In some cases, the polymer material is dissolved. Further, the present invention is not necessarily limited to such a form. For example, when there is a heat treatment step in the electrode production process or the battery production process, preferably in the electrode production process, the heat treatment is included in the active material layer. In some cases, the polymer material contained in the resin layer is sufficiently dissolved in the solvent to adhere to the active material layer.

  After the active material layer is formed, the solvent is removed by drying. An electrolyte may be impregnated after forming the active material layer. For example, in the case of a gel polymer electrolyte, the solvent contained in the gel polymer electrolyte can be removed together by impregnating the active material layer with the electrolyte and then drying. Heat may be applied during drying. By this heat treatment, the polymer material contained in the resin layer is dissolved in the solvent contained in the active material layer and may adhere to the active material layer.

  Next, a battery to which the electrode of the first embodiment is applied will be described. The type of battery to which the electrode of the first embodiment is applied is not particularly limited, and examples thereof include a nonaqueous electrolyte battery, preferably a lithium ion secondary battery. This is because in the lithium ion secondary battery, the voltage of the cell (single battery layer) is large, high energy density and high output density can be achieved, and the lithium ion secondary battery is excellent as a vehicle driving power source or an auxiliary power source. In addition, when distinguished by the structure and form of the battery, it is not particularly limited such as a stacked (flat) battery or a wound (cylindrical) battery, and can be applied to any conventionally known structure.

  When viewed in terms of the electrical connection form (electrode structure) in the nonaqueous electrolyte secondary battery, it can be applied to both (internal parallel connection type) batteries and bipolar (internal series connection type) batteries. Preferably, as described above, the effect of the present invention is remarkably exhibited in the case of the bipolar type.

  Similarly, there is no particular limitation in the case of distinguishing by the form of the electrolyte of the nonaqueous electrolyte battery. For example, the present invention can be applied to any of a liquid electrolyte type battery in which a separator is impregnated with a nonaqueous electrolytic solution, a polymer gel electrolyte type battery also called a polymer battery, and a solid polymer electrolyte (all solid electrolyte) type battery. With respect to the polymer gel electrolyte and the solid polymer electrolyte, these can be used alone, or the polymer gel electrolyte or the solid polymer electrolyte can be used by impregnating the separator.

  A bipolar lithium ion secondary battery, which is a preferred embodiment, will be described below.

  The bipolar lithium ion secondary battery 10 of this embodiment shown in FIG. 3 has a structure in which a substantially rectangular power generation element 21 in which a charge / discharge reaction actually proceeds is sealed inside a laminate sheet 29 that is a battery exterior material. Have

  As shown in FIG. 3, the power generation element 21 of the bipolar lithium ion secondary battery 10 of this embodiment includes a plurality of bipolar electrodes 1. The bipolar electrode 1 has a structure in which a positive electrode active material layer 13 is provided on one side of a current collector 11 and a negative electrode active material layer 15 is provided on the other side. The bipolar lithium ion secondary battery 11 includes a positive electrode active material layer 13 on one surface of a current collector 11 and a bipolar electrode 1 having a negative electrode active material layer 15 on the other surface. A power generation element 21 having a structure in which a plurality of layers are stacked via a gap is provided.

  The adjacent positive electrode active material layer 13, electrolyte layer 17, and negative electrode active material layer 15 constitute one single battery layer (= battery unit or single cell) 19. Therefore, it can be said that the bipolar lithium ion secondary battery 10 has a configuration in which the single battery layers 19 are stacked. In addition, an insulating layer (seal part) 31 is disposed in the periphery of the unit cell layer 19 in order to prevent liquid junction due to leakage of the electrolyte from the unit cell layer 19. By providing the insulating layer (seal part) 31, it is possible to insulate between the adjacent current collectors 11 and prevent a short circuit due to contact between the adjacent electrodes (positive electrode 13 and negative electrode 15). The current collectors located in the outermost layers are the outermost current collectors 11a and 11b, on which either the positive electrode active material layer 13 or the negative electrode active material layer 15 is formed only on one side. .

  A positive electrode current collector plate 25 and a negative electrode current collector plate 27 are provided further outside the outermost layer current collectors 11a and 11b. These current collecting plates 25 and 27 are extended and led out from a laminate sheet 29 which is a battery outer packaging material to be a positive electrode tab and a negative electrode tab. In addition, the current collector plates 25 and 27 are formed thicker than the current collector 11 so that the current from the plurality of unit cell layers 19 stacked can be easily taken out.

  Note that a separate tab may be electrically connected to the current collector plate. Further, instead of the current collector plate, the outermost layer current collectors 11a and 11b may be electrically connected to the positive electrode tab and the negative electrode tab as they are. At this time, the outermost layer current collector (11a, 11b) and the tab may be electrically connected via a positive terminal lead and a negative terminal lead. Furthermore, instead of the current collector plate, the outermost layer current collectors 11a and 11b may be thickened and directly extended outside the laminate sheet 29 to form a positive electrode tab and a negative electrode tab. Further, an electrode active material layer may be provided between the outermost layer current collectors 11 a and 11 b and the current collector plates 25 and 27. That is, the current collectors 11a and 11b dedicated to the outermost layer provided with the electrode active material only on one side may be used as the current collector of the outermost layer as it is, instead of the current collector 11 having the electrode active material on both sides. It's good.

  In the bipolar lithium ion secondary battery, current flows in the vertical direction due to the above-described configuration. Therefore, the path of electronic conduction is significantly shorter than that of the non-bipolar stacked battery, and the output is correspondingly higher.

  Further, since a current collector containing a polymer material is used as the current collector, the weight of the battery can be reduced.

  Hereinafter, although the member which comprises the bipolar lithium ion secondary battery 10 of this embodiment is demonstrated easily, it describes above about the component which comprises an electrode among the components of the said bipolar lithium ion secondary battery. The description is omitted here because it is the same as described above.

[Electrolyte layer]
The electrolyte constituting the electrolyte layer 17 is not particularly limited as long as it has a function as a lithium ion carrier that moves between positive and negative electrodes during charge and discharge, and is a liquid electrolyte, a polymer electrolyte, an inorganic solid electrolyte (oxide type) Solid electrolytes, sulfide-based solid electrolytes) and the like can be used.

The liquid electrolyte has a form in which a lithium salt as a supporting salt is dissolved in an organic solvent as a plasticizer. Examples of the organic solvent that can be used as the plasticizer include carbonates such as ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), and diethyl carbonate (DEC). As the supporting salt (lithium _{salt), Li (CF 3 SO 2} ) 2 N, Li (C 2 F 5 SO 2) 2 N, LiPF 6, LiBF 4, LiAsF 6, LiTaF 6, LiClO 4, LiCF 3 A compound that can be added to the active material layer of the electrode, such as SO _3, can be similarly employed.

  On the other hand, the polymer electrolyte is classified into a gel electrolyte containing an electrolytic solution and an intrinsic (all solid) polymer electrolyte containing no electrolytic solution.

  The gel polymer electrolyte has a configuration in which the liquid electrolyte is injected into a matrix polymer (host polymer). Using a gel polymer electrolyte as the electrolyte is superior in that the fluidity of the electrolyte is lost, the electrolyte is prevented from flowing out to the current collector layer, and the ionic conductivity between the layers can be easily blocked. The matrix polymer (host polymer) is not particularly limited. For example, polyethylene oxide (PEO), polypropylene oxide (PPO), polyvinylidene fluoride (PVdF), a copolymer of polyvinylidene fluoride and hexafluoropropylene (PVdF-HFP). ), Polyethylene glycol (PEG), polyacrylonitrile (PAN), polymethyl methacrylate (PMMA), and copolymers thereof.

  Examples of the intrinsic polymer electrolyte include polyether polymer electrolytes such as polyethylene oxide (PEO) and polypropylene oxide (PPO). Usually, it has a structure in which a supporting salt (lithium salt) is dissolved in an intrinsic polymer electrolyte, and does not include an organic solvent that is a plasticizer. Therefore, by using the intrinsic polymer electrolyte as the electrolyte, the fluidity of the electrolyte is lost, the electrolyte is prevented from flowing out to the current collector layer, and the ion conductivity between the layers can be easily blocked.

  The matrix polymer of gel polymer electrolyte or intrinsic polymer electrolyte can express excellent mechanical strength by forming a crosslinked structure. In order to form a crosslinked structure, thermal polymerization, ultraviolet polymerization, radiation polymerization, electron beam polymerization, etc. are performed on a polymerizable polymer (for example, PEO or PPO) for forming a polymer electrolyte using an appropriate polymerization initiator. A polymerization treatment may be performed.

  In addition, when an electrolyte layer is comprised from a liquid electrolyte or a gel electrolyte, you may use a separator for an electrolyte layer. Specific examples of the separator include a microporous film made of polyolefin such as polyethylene or polypropylene.

[Outermost layer current collector]
Examples of the outermost layer current collector include an aluminum foil, a stainless steel (SUS) foil, a clad material of nickel and aluminum, a clad material of copper and aluminum, or a plated material of a combination of these metals. In order to obtain a current collector that can withstand both negative electrode potentials, aluminum foil and stainless steel foil are preferred. A current collector containing the above polymer material may be used as the outermost layer current collector. The current collector plates 25 and 27 can also be formed of the same material as the current collector.

[Tab (positive tab and negative tab)]
Tabs (positive electrode tab 25 and negative electrode tab 27) that are electrically connected to each current collector are taken out of the battery exterior material for the purpose of taking out the current outside the battery.

  The material constituting the tabs (the positive electrode tab 25 and the negative electrode tab 27) is not particularly limited, and a known highly conductive material conventionally used as a tab for a lithium ion secondary battery can be used. As a constituent material of the tab, for example, metal materials such as aluminum, copper, titanium, nickel, stainless steel (SUS), and alloys thereof are preferable, and aluminum, copper, and the like are more preferable from the viewpoint of light weight, corrosion resistance, and high conductivity. Is preferred. Note that the same material may be used for the positive electrode tab 25 and the negative electrode tab 27, or different materials may be used. Further, the outermost layer current collectors 11a and 11b may be extended to form the positive electrode tab 25 and the negative electrode tab 27, or the separately prepared positive electrode tab 25 and negative electrode tab 27 are connected to the outermost layer current collectors 11a and 11b. Also good.

[Positive electrode and negative electrode lead]
The positive terminal lead and the negative terminal lead are also used as necessary. For example, when the positive electrode tab 25 and the negative electrode tab 27 which are output electrode terminals are directly taken out from the outermost layer current collectors 11a and 11b, the positive electrode terminal lead and the negative electrode terminal lead may not be used.

  As the material of the positive terminal lead and the negative terminal lead, a terminal lead used in a known lithium ion secondary battery can be used. It should be noted that the part taken out from the battery outer packaging material 29 has a heat insulating property so as not to affect the product (for example, automobile parts, particularly electronic devices) by contacting with peripheral devices or wiring and causing leakage. It is preferable to coat with a heat shrinkable tube or the like.

[Battery exterior materials]
As the battery exterior material 29, a known metal can case can be used, and a bag-like case using a laminate film containing aluminum that can cover a power generation element (battery element) can be used. For example, a laminate film having a three-layer structure in which PP, aluminum, and nylon are laminated in this order can be used as the laminate film, but the laminate film is not limited thereto. A laminate film that is excellent in high output and cooling performance and that can be suitably used for a battery for large equipment for EV and HEV is desirable.

  Although the bipolar lithium ion secondary battery according to the preferred embodiment of the present invention has been described above, it is needless to say that a non-bipolar lithium ion secondary battery may be used. As an example of a non-bipolar lithium ion secondary battery, a positive electrode in which a positive electrode active material layer is formed on both sides of a positive electrode current collector, an electrolyte layer, and a negative electrode active material layer on both sides of a negative electrode current collector A configuration in which a plurality of negative electrodes thus formed is laminated is exemplified. At this time, the positive electrode, the electrolyte layer, and the negative electrode are laminated in this order so that the positive electrode active material layer on one side of one positive electrode and the one negative electrode adjacent to the one positive electrode face each other through the electrolyte layer. Similarly to the bipolar type, the positive electrode tab and the negative electrode tab connected to each electrode (positive electrode and negative electrode) are connected to the positive electrode current collector and the negative electrode current collector of each electrode via the positive electrode terminal lead and the negative electrode terminal lead. It is attached by ultrasonic welding or resistance welding. Thereby, the positive electrode tab and the negative electrode tab have a structure exposed to the exterior of said battery exterior material from the site | part joined by heat sealing | fusing of the peripheral part of the laminate film.

  The battery of the present invention can be produced by a conventionally known production method except that the above-described electrode is used.

[External battery configuration]
FIG. 4 is a perspective view showing the appearance of a stacked flat non-bipolar or bipolar lithium ion secondary battery which is a typical embodiment of the battery according to the present invention.

  As shown in FIG. 4, the stacked flat lithium ion secondary battery 50 has a rectangular flat shape, and a positive electrode tab 58 and a negative electrode tab 59 for taking out electric power from both sides thereof. Has been pulled out. The power generation element (battery element) 57 is wrapped by the battery outer packaging material 52 of the lithium ion secondary battery 50, and the periphery thereof is heat-sealed. The power generation element (battery element) 57 includes a positive electrode tab 58 and a negative electrode tab 59. It is sealed in a state where it is pulled out to the outside. Here, the power generation element (battery element) 57 corresponds to the power generation element (battery element) 21 of the bipolar lithium ion secondary battery 10 shown in FIG. 3 described above. In addition, a plurality of single battery layers (single cells) 19 including a positive electrode (positive electrode active material layer) 13, an electrolyte layer 17, and a negative electrode (negative electrode active material layer) 15 are laminated. Note that the present invention is not limited to a laminated flat shape as shown in FIG. The wound lithium ion battery may have a cylindrical shape, or may be a rectangular flat shape obtained by deforming such a cylindrical shape. In the said cylindrical shape thing, a laminate film may be used for the exterior material, and the conventional cylindrical can (metal can) may be used, for example, It does not restrict | limit.

  Also, the removal of the tabs 58 and 59 shown in FIG. 4 is not particularly limited. The positive electrode tab 58 and the negative electrode tab 59 may be pulled out from the same side, or the positive electrode tab 58 and the negative electrode tab 59 may be divided into a plurality of parts and taken out from each side, as shown in FIG. It is not limited to. Further, in a wound type lithium ion battery, instead of a tab, for example, a terminal may be formed using a cylindrical can (metal can).

[Battery]
The assembled battery of the present invention is formed by connecting a plurality of the batteries of the present invention. Specifically, at least two or more are used, and are configured by serialization, parallelization, or both. Capacitance and voltage can be freely adjusted by paralleling in series. In the assembled battery of the present invention, a non-bipolar lithium ion secondary battery and a bipolar lithium ion secondary battery are used, and these are combined in series, in parallel, or in series and in parallel. A battery can also be constructed.

  5 is an external view of a typical embodiment of the assembled battery according to the present invention, FIG. 5A is a plan view of the assembled battery, FIG. 5B is a front view of the assembled battery, and FIG. It is a side view of an assembled battery.

  As shown in FIG. 5, the assembled battery 300 according to the present invention forms a small assembled battery 250 that can be attached and detached by connecting a plurality of bipolar lithium ion secondary batteries in series or in parallel. A large capacity and large output suitable for a vehicle driving power source and an auxiliary power source that require a high volume energy density and a high volume output density by connecting a plurality of these detachable small assembled batteries 250 in series or in parallel. It is also possible to form an assembled battery 300 having 5A is a plan view of the assembled battery, FIG. 5B is a front view, and FIG. 5 is a side view. The small assembled battery 250 that can be attached and detached is provided with an electrical connection means such as a bus bar. The assembled battery 250 is stacked in a plurality of stages using the connection jig 310. How many lithium ion secondary batteries are connected to produce the assembled battery 250, and how many assembled batteries 250 are laminated to produce the assembled battery 300 depends on the vehicle (electric vehicle) to be mounted. It may be determined according to the battery capacity and output.

[vehicle]
The vehicle of the present invention is equipped with the battery of the present invention or an assembled battery formed by combining a plurality of these. Since the battery of the present invention has a high output, when the battery is mounted, a plug-in hybrid electric vehicle having a long EV travel distance or an electric vehicle having a long charge travel distance can be configured. In other words, the non-aqueous electrolyte secondary battery of the present invention or the assembled battery formed by combining a plurality of these can be used as a power source for driving a vehicle. Examples of vehicles include hybrid vehicles, fuel cell vehicles, and electric vehicles (all are automobiles (commercial vehicles such as passenger cars, trucks, buses, light vehicles, etc.), motorcycles, and tricycles. ). However, the application is not limited to automobiles, and it can be applied to various power sources for other vehicles, for example, moving bodies such as trains, and can be used as a power source for mounting such as an uninterruptible power supply. It is also possible to do.

  FIG. 6 is a conceptual diagram of a vehicle equipped with the assembled battery of the present invention.

  As shown in FIG. 6, in order to mount the assembled battery 300 on a vehicle such as the electric vehicle 400, the battery pack 300 is mounted under the seat at the center of the vehicle body of the electric vehicle 400. This is because if it is installed under the seat, the interior space and the trunk room can be widened. The place where the assembled battery 300 is mounted is not limited to the position under the seat, but may be a lower part of the rear trunk room or an engine room in front of the vehicle. The electric vehicle 400 using the assembled battery 300 as described above can provide a sufficient output.

The effects of the present invention will be described using the following examples and comparative examples. However, the technical scope of the present invention is not limited only to the following examples.
Example 1
1. Preparation of negative electrode slurry Slurry viscosity adjustment for a mixture of artificial graphite (MAG-D, manufactured by Hitachi Chemical Co., Ltd.) (90% by mass) as a negative electrode active material and polyimide (PI) powder (10% by mass) as a binder A negative electrode slurry was prepared by adding N-methyl-2-pyrrolidone (NMP) as a solvent to a solid content of 50% by mass. The SP value of polyimide was 16.9, and the SP value of NMP was 11.2.

2. Preparation of current collector Pellets of PVDF resin were kneaded while being melted at 230 ° C., and acetylene black was mixed little by little during kneading until 15 mass%. After introduction of acetylene black, the resin was extruded from the slit, cooled with water, and formed into a sheet having a thickness of about 50 μm. This sheet had Ra of 0.1 μm and Rz of 0.8 μm. In addition, the surface roughness meter (model number SURFCOM575A-3DF (made by Tokyo Seimitsu Co., Ltd.)) was used for the measurement of surface roughness.

3. Production of electrodes The slurry prepared in (1) was applied to both sides of the current collector, and dried at 80 ° C. for 5 minutes to prepare an electrode having a thickness of 20 μm.

(Example 2)
N-methyl-2-2, which is a slurry viscosity adjusting solvent, for a mixture of artificial graphite (MAG-D, manufactured by Hitachi Chemical Co., Ltd.) (90% by mass) as a negative electrode active material and PVDF (10% by mass) as a binder. Pyrrolidone (NMP) was added to a solid content of 50% by mass to prepare a negative electrode slurry. An electrode was produced in the same manner as in Example 1 except that this slurry was used. The SP value of PVDF was 9.1.

(Example 3)
N-methyl-2-2, which is a slurry viscosity adjusting solvent, for a mixture of artificial graphite (MAG-D, manufactured by Hitachi Chemical Co., Ltd.) (90% by mass) as a negative electrode active material and PVDF (10% by mass) as a binder. Pyrrolidone (NMP) was added to a solid content of 30% by mass to prepare a negative electrode slurry. An electrode was produced in the same manner as in Example 1 except that this slurry was used.

Example 4
1. Preparation of Negative Electrode Slurry N is a slurry viscosity adjusting solvent for a mixture of artificial graphite (MAG-D, manufactured by Hitachi Chemical Co., Ltd.) (90% by mass) as a negative electrode active material and PVDF (10% by mass) as a binder. -Methyl-2-pyrrolidone (NMP) was added to a solid content of 25% by mass to prepare a negative electrode slurry. An electrode was produced in the same manner as in Example 1 except that this slurry was used.

2. Preparation of current collector Pellets of PVDF resin were kneaded while being melted at 230 ° C., and acetylene black was mixed little by little during kneading until 15 mass%. After introduction of acetylene black, the resin was extruded from the slit, cooled with water, and formed into a sheet having a thickness of about 50 μm. Both sides of the obtained sheet were roughened with sandpaper. This sheet had Ra of 3.5 μm and Rz of 22 μm.

3. Production of electrodes The slurry prepared in (1) was applied to both sides of the current collector, and dried at 80 ° C. for 5 minutes to prepare an electrode having a thickness of 21 μm.

(Example 5)
1. Preparation of positive electrode slurry LiMn ₂ O ₄ (84% by mass) as a positive electrode active material, acetylene black (3% by mass) as a conductive additive, vapor grown carbon fiber (VGCF (registered trademark); manufactured by Showa Denko KK) 3% by mass) and a mixture of PVDF (10% by mass) as a binder, N-methyl-2-pyrrolidone (NMP) as a slurry viscosity adjusting solvent was added so as to have a solid content of 35% by mass. An electrode slurry was prepared.

  A negative electrode slurry and a current collector were prepared in the same manner as in Example 4. A negative electrode slurry was applied to one side of the current collector. The other side of the current collector was similarly roughened with sandpaper (Ra 2.9 μm, Rz 19 μm). The positive electrode slurry was applied to the current collector surface roughened with a doctor blade, and then dried at 80 ° C. for 5 minutes. The dried negative electrode film thickness was 19 μm, and the positive electrode film thickness was 22 μm.

(Comparative Example 1)
As a negative electrode active material, a mixture of artificial graphite (MAG-D, manufactured by Hitachi Chemical Co., Ltd.) (90% by mass), SBR (3% by mass) as a binder, and CMC (carboxymethylcellulose) (3% by mass) as a thickener On the other hand, water which is a slurry viscosity adjusting solvent was added so as to have a solid content of 50% by mass to prepare a negative electrode slurry. An electrode was produced in the same manner as in Example 1 except that this slurry was used. The SP value of SBR was 8.4 and the SP value of water was 23.4.

(Comparative Example 2)
Slurry with respect to a mixture of artificial graphite (MAG-D, manufactured by Hitachi Chemical Co., Ltd.) (90% by mass) as a negative electrode active material, and SBR (3% by mass) and CMC (carboxymethylcellulose) (3% by mass) as a binder Water as a viscosity adjusting solvent was added so as to have a solid content of 30% by mass to prepare a negative electrode slurry. An electrode was produced in the same manner as in Example 1 except that this slurry was used. However, in Comparative Example 2, since the resin repelled the slurry, the slurry could not be applied (cannot be maintained as an electrode after coating and drying), and therefore the following resistance value and peel strength could not be measured.

(Evaluation Example 1: Internal resistance of battery)
The electrodes obtained in Examples 1 to 5 and Comparative Examples 1 and ² were cut into 10 × 10 cm ² and sandwiched between Al plates having the same area, and the resistance between the Al plates was measured. The results are shown in Table 1.

(Evaluation Example 2: Peel strength test)
The peel strength test of the electrodes obtained in Examples 1 to 4 and Comparative Examples 1 and 2 was performed. The peel strength test was performed by a peel strength test method: 180 ° and a tensile speed: 50 mm / min.
The results are shown in Table 2.

  From the above results, it can be seen that the electrodes of Examples 1 to 4 have lower internal resistance and improved peel strength than the electrodes of Comparative Examples 1 and 2.

It is a conceptual diagram which shows the structure of the bipolar electrode of this invention. It is a schematic diagram which shows the structure of the bipolar electrode of this invention. It is a schematic diagram which shows the bipolar battery of this invention. It is an external view of the bipolar battery of the present invention. It is an external view of the assembled battery of this invention. It is a conceptual diagram of the vehicle carrying the assembled battery of this invention.

Explanation of symbols

1 Bipolar electrode,

3 positive electrode active material,
5 conductive filler,
10 Bipolar lithium ion secondary battery,
2, 11 current collector,
11a The outermost layer current collector on the positive electrode side,
11b The outermost layer current collector on the negative electrode side,
4, 13 Positive electrode active material layer,
15 negative electrode active material layer,
17 electrolyte layer,
19 cell layer,
21, 57 Power generation element (battery element; laminate),
25 positive current collector,
27 negative current collector,
29, 52 Exterior material (for example, laminate sheet),
31 insulating layer,
50 lithium ion secondary battery,
58 positive electrode tab,
59 Negative electrode tab,
250 small battery pack,
300 battery packs,
310 connection jig, 400 electric vehicle.

Claims (11)

  A current collector including a resin layer having conductivity and an active material layer formed on the resin layer and including an active material, and the resin layer surface is dissolved in a solvent so that the surface of the resin layer is the active material An electrode bonded to a layer.   The electrode according to claim 1, wherein the resin layer includes a conductive filler, and the conductive filler protrudes into the active material layer at an interface between the resin layer and the active material layer.   The electrode according to claim 1 or 2, which is a bipolar type.   The electrode according to claim 3, wherein the volume resistivity is 0.1 to 1.0 mΩ · cm.   The electrode according to any one of claims 1 to 4, wherein a material constituting the binder contained in the active material layer and a polymer material contained in the resin layer are the same. A step of mixing an active material, a binder and a solvent to obtain an active material slurry;
Applying the active material slurry onto a resin layer of a current collector including a resin layer having conductivity, and
The method for producing an electrode, wherein the solvent is a solvent that dissolves a polymer material contained in the resin layer.   The method for producing an electrode according to claim 6, wherein the surface roughness of the current collector on the resin layer side when applying the active material slurry is 0.3 <Ra <5 μm and 3 <Rz <30 μm.   The manufacturing method of the electrode of Claim 6 or 7 whose solid content rate of the said active material slurry is 40 mass% or less.   The battery using the electrode obtained by the electrode manufacturing method of any one of Claims 1-5, or the electrode manufacturing method of any one of Claims 6-8.   An assembled battery in which a plurality of the batteries according to claim 9 are connected.   A vehicle on which the battery according to claim 9 or the assembled battery according to claim 10 is mounted as a power source for driving a motor.

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