JP5124961B2 - Bipolar battery - Google Patents

Description

The present invention relates to a bipolar batteries.

  The bipolar battery has a structure in which a plurality of electrodes each having a positive electrode provided on one surface and a negative electrode provided on the other surface are stacked with an electrolyte layer interposed therebetween.

  In such a bipolar battery, an electrolyte layer holding an electrolytic solution in a polymer skeleton is used. In order to prevent leakage of the electrolyte from the electrolyte, a sealing material is collected between the current collectors so as to surround each unit cell composed of each positive electrode, electrolyte, and negative electrode sandwiched between the stacked current collectors. It is provided so as to adhere to an electric body (Patent Document 1).

  This is because, in bipolar batteries, there are multiple single cells consisting of a positive electrode, an electrolyte, and a negative electrode sandwiched between current collectors in one package, so if the electrolyte leaks from one single cell, Therefore, in order to prevent this, a sealing material is provided for each single cell.

On the other hand, in a normal lithium ion secondary battery (secondary battery other than a bipolar battery), first, a battery element in which a positive electrode, a separator, and a negative electrode are arranged in this order is manufactured. In some cases, an electrolytic solution is poured into a bag-like laminate film and then the laminate film bag is closed (see, for example, Patent Document 2).
JP 09-23003 A JP 2001-332307 A (paragraphs 0076 to 0078, etc.)

  In the conventional bipolar battery, as described above, there are a plurality of single cells in one package, and the electrolyte layer is sealed with a sealing material so that the electrolyte does not leak for each single cell. It has a structure.

  For this reason, like a normal secondary battery, it is not possible to take a manufacturing method in which a battery element excluding the electrolyte is first prepared and the electrolyte is injected later.

  On the other hand, bipolar batteries have many members to be stacked. For example, there is a structure in which 100 or more layers of current collectors in which a positive electrode and a negative electrode are formed in advance are stacked with an electrolyte layer interposed therebetween. In such a bipolar battery, a plurality of electrolyte layers holding a liquid are interposed between current collectors, and a sealing material must be disposed around the electrolyte layer, and they are stacked. There are problems that manufacturing is difficult because there are only a few, and this contributes to an increase in manufacturing cost.

Therefore, an object of the present invention is to provide a bipolar battery that is easy to manufacture .

To achieve the above object, the present invention provides a current collector in which a positive electrode is provided on a first surface and a negative electrode is provided on a second surface facing the first surface, and the positive electrode and the negative electrode are opposed to each other. An electrolyte layer interposed between the plurality of stacked current collectors, and disposed between the current collectors so as to surround the positive electrode, the electrolyte layer, and the negative electrode, and the current collector outer peripheral portion the close contact with the positive electrode and the non-formation portion of the negative electrode, and a, and the sealing material having an opening part, a sealing material to fill the opening of the sealing material, was perforated, the openings, The bipolar battery is provided at different positions in the stacking direction of the current collector.

According to the bipolar batteries of the present invention, by providing a positive electrode sandwiched between the current collectors, an electrolyte layer, and an opening in disposed sealant so as to surround the negative electrode, to form a positive electrode and a negative electrode After a plurality of current collectors are stacked, a fluid electrolyte can be injected from the opening. Therefore, according to the present invention, unlike a conventional bipolar battery, it is not necessary to maintain a state in which a current collector and a fluid electrolyte are held between a plurality of current collectors, and a solid that is relatively easy to handle. Since a plurality of current collectors and sealing materials, which are substances, are stacked, an electrolyte that is a fluid can be injected later, so that manufacturing is facilitated and manufacturing cost can be reduced.

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1)
1A and 1B are explanatory views for explaining the structure of a bipolar battery according to a first embodiment to which the present invention is applied. FIG. 1A is a plan view, and FIG. 1B is along the line BB in FIG. It is sectional drawing.

  In this bipolar battery 1, a positive electrode 3 and a negative electrode 4 are formed on both surfaces of one current collector 2. This is called a bipolar electrode.

  Between the stacked current collectors 2 and 2, a single cell is constituted by the positive electrode 3, the electrolyte layer 5, and the negative electrode 4. That is, the structure is such that the positive electrode 3 provided in one current collector 2, the negative electrode 4 provided in the adjacent current collector 2, and the electrolyte layer 5 is sandwiched between the positive electrode 3 and the negative electrode 4. Thus, one unit cell is configured.

  And the sealing material 8 is provided so that one single cell may be surrounded.

  The sealing material 8 is disposed between the stacked current collectors 2 and prevents liquid leakage from the electrolyte layer for each unit cell.

  An opening 15 is provided in the sealing material 8. The opening 15 is used for injecting an electrolyte (electrolytic solution) in a manufacturing method described later. The electrolyte is held by the spacer 18 (see FIG. 6) to become the electrolyte layer 5.

  The opening 15 is sealed by the sealing material 7 when the bipolar battery 1 is completed (the state shown in FIG. 1). Therefore, liquid leakage does not occur from the opening 15 in a state where the bipolar battery 1 is completed. The sealing material 7 may be referred to as a post-seal material in contrast to the previously provided seal material 8 in order to seal the opening 15 after electrolyte injection.

  Preferably, at least one opening 15 is provided on opposite sides of the bipolar battery 1. In the example shown in FIG. 1A, two (a total of four) openings 15 are provided on each side on the short side 2a side.

  The reason for this is that, in the manufacturing method described later, by providing openings 15 on two opposing sides, so that one opening 15 is immersed in the electrolyte liquid and sucked up from the other opening 15, the current collector 2 and the current collector 2, more precisely, the space between the positive electrode 3 and the negative electrode 4, and the electrolyte can be spread evenly and evenly.

(Embodiment 2)
In addition, the position of the opening 15 can be various positions other than those shown in FIG.

  2 and 3 are plan views of the bipolar battery 1 for explaining examples of other positions of the opening 15. The second embodiment is the same as the first embodiment except for the position of the opening 15.

  The position of the opening 15 may be, for example, two sides on the long side 2b side as shown in FIG. 2, or may be an opposite corner 2c portion as shown in FIG. That is, it is only necessary that the opening 15 is located opposite to the electrolyte layer of the sealing material 8.

(Embodiment 3)
Furthermore, the opening 15 is not limited to these.

  4A and 4B are diagrams showing an example in which an opening 15 is provided on one side, where FIG. 4A is a plan view of the bipolar battery 1, and FIG. 4B is a cross-sectional view taken along line B1-B2 of FIG. It is.

  In this example, two openings 15 are provided on one side. In this way, when the opening is provided only on one side, for example, the whole is immersed in the electrolyte solution, and the whole is kept under reduced pressure so that the air is removed and the electrolyte is dispersed. An electrolyte may be injected. Also, by immersing two or more openings in one side, pressure injection of the electrolyte is performed from one opening, and the air inside the pressure injection of the other opening 15 is released. It may be.

(Embodiment 4)
5 is a bipolar battery in which the position of the opening 15 is further changed. FIG. 5 (a) is a plan view of the bipolar battery, and FIG. 5 (b) is a side view of the bipolar battery (side with the opening 15). ).

  In the fourth embodiment, the openings 15 provided in each of the sealing materials 8 sandwiched between the current collectors 2 are positioned so as not to overlap in the stacking direction in the stacked state.

  The bipolar battery 1 has a structure in which an electrolyte layer 5 is laminated between a plurality of bipolar electrodes (consisting of a current collector 2, a positive electrode 3, and a negative electrode 4) as described above. Therefore, the sealing material 8 is also sandwiched between the plurality of current collectors 2. On the other hand, the opening 15 is sealed with the sealing material 7 after the electrolyte is injected.

  In this way, even when the sealing material 7 expands and the thickness increases by making the position of the opening 15 a position that does not overlap in the stacking direction in the stacked state, the stacked battery As a whole, it is possible to prevent the thickness of the portion including the sealing material 7 from locally increasing.

  Further, in order to prevent a short circuit when performing the initial charging described later, it is necessary to sufficiently wipe and dry the electrolyte around the opening 15, but the opening 15 does not overlap in the stacking direction. Since the distance between them can be increased, the wiping and drying operations can be simplified.

  In the bipolar battery 1 according to the fourth embodiment, an example in which one opening 15 (that is, a portion into which the sealing material 7 enters) is provided on only one side surface in FIG. 5 is described above. The same applies to the case where the opening 15 is provided on the opposite side as in the first to third embodiments or the case where the plurality of openings 15 are provided on one side.

  In the illustrated example, the positions of all the openings 15 are not overlapped in the stacking direction in a stacked state, but this may be the same position when the number of stacks is increased. Therefore, in the case of actual manufacture, the position may be as different as possible depending on the length of one side and the size of the opening 15, etc. It is possible to prevent a local increase in thickness as compared with the case where they are provided at the same position.

(Embodiment 5)
6A and 6B are explanatory views for explaining the bipolar battery 1 in which the position of the opening 15 is further changed. FIG. 6A is a plan view and FIG. 6B is an explanatory view for explaining a manufacturing method. It is.

  As shown in FIG. 6A, the bipolar battery 1 of Embodiment 5 has one opening 15 provided at the corner of the current collector 2.

  As a method for injecting the electrolyte, it is possible to employ a method in which the electrolyte is directly injected into each layer surrounded by the sealing material 8 using an injection means such as a tube or a nozzle (arrow A in the figure).

  In the fifth embodiment, when direct injection using such an injection means is performed, the opening 15 serving as a liquid injection portion is provided at the corner, so that the side of the battery as shown in FIG. 1 or FIG. It is possible to open the opening 15 serving as a liquid injection port larger than in the case where an opening is provided in the portion corresponding to. Therefore, it becomes easy to inject an electrolyte directly into each layer using a tube, a nozzle, etc., and productivity improves when injecting an electrolyte using a tube, a nozzle.

(Embodiment 6)
7A and 7B are explanatory views for explaining another bipolar battery 1, in which FIG. 7A is a plan view, and FIG. 7B is a cross-sectional view taken along line BB in FIG. 7A.

  The bipolar battery 1 of Embodiment 6 is provided with a spacer 18 wider than the outer periphery of the current collector 2.

  The spacer 18 is disposed between the electrodes (between the positive electrode 3 and the negative electrode 4). The spacer 18 insulates the electrodes and is impregnated with an electrolyte, so that the spacer 18 functions as the electrolyte layer 5 and transmits only ions. In other words, the electrolyte layer 5 is made of an electrolyte impregnated inside the sealing material 8 of the spacer 18 wider than the current collector 2.

  The sealing material 8 may be the same as in the other embodiments. For example, a thermosetting resin that is liquid at room temperature (described later in detail) or the like is applied to a portion that becomes the sealing material 8 and is soaked in the spacer 18. The sealing material 8 is formed by heating and pressing.

  By making the spacer 18 wider than the current collector 2 in this way, it is possible to prevent the current collectors 2 from contacting each other at the periphery thereof, and to improve the insulation.

(Embodiment 7)
FIG. 8 is a cross-sectional view for explaining another embodiment of the spacer.

  In the seventh embodiment, like the sixth embodiment, the spacer 18 is wider than the current collector 2. However, as a manufacturing method thereof, an adhesive 19 is impregnated in advance on the periphery of the spacer 18 and the portion to be the sealing material 8.

  In this manner, bipolar electrodes (consisting of the current collector 2, the positive electrode 3 and the negative electrode 4) and the spacers 18 are alternately stacked, and then the surroundings are pressurized and heated, so that before the electrolyte is injected into the bipolar battery. It is possible to manufacture easily up to the state.

  In addition, as an adhesive agent, the thermosetting resin used for a sealing material can be used, for example.

(Embodiment 8)
FIG. 9 is a plan view for explaining still another form of the spacer.

  In the eighth embodiment, the entire spacer 18 is made wider than the current collector 2, and an overhanging portion 180 is provided at a portion corresponding to the opening 15. FIG. 9A shows a case where the opening is provided in the side portion, and FIG. 9B shows a case where the opening is provided in the corner portion.

  The projecting portion 180 may be the same as the spacer 18, or may be a projecting portion by sticking another member to a portion of the spacer 18 that contacts the opening 15.

  By providing the overhanging portion 180 in this way, the position of the opening becomes easy to understand, and when the electrolyte is directly injected using a tube or a nozzle, the opening 15 can be opened with the overhanging portion 180. Therefore, the electrolyte can be easily injected.

  Hereinafter, the sealing material 8, the current collector 2, the positive electrode 3, the negative electrode 4, the electrolyte layer 5, and the like, which are members common to the respective embodiments described above, will be described.

[Sealant]
The sealing material 8 provided with the opening 15 will be described.

This sealing material 8 is, for example, a resin material. As the resin material, a material that is fused (adhered) to the current collector 2 by heat by pressure heating is preferable. Examples of the resin material having such heat-fusibility include polypropylene (PP: melting point 160 to 170 ° C., thermal expansion coefficient 8.5 × 10 ⁻⁵ / ° C.), polyethylene (PE: melting point (linear low density). General-purpose plastics such as about 130 ° C., coefficient of thermal expansion 16-18 × 10 ⁻⁵ / ° C.), polyurethane (melting point: 105 ° C. or 130 ° C., coefficient of thermal expansion 10-20 × 10 ⁻⁵ / ° C.) Polyamide resins such as nylon 6 (Nylon is a registered trademark, the same applies hereinafter) (melting point 225 ° C., coefficient of thermal expansion 8-13 × 10 ⁻⁵ / ° C.), nylon 66 (melting point 267 ° C., heat expansion coefficient of ^{10~15 × 10 -5 / ℃))} , polytetrafluoroethylene (PTFE: mp 320 ° C., thermal expansion coefficient of 8.3~10.5 × ^{10 -5} / ℃), polystyrene (melting point 30 ° C., thermal expansion coefficient of 6~8 × ^{10 -5} / ℃) or the like can be used.

  In order to form the sealing material 8 on the current collector 2 using these resin materials, for example, a precursor of these resin materials is formed on the current collector 2 by a printing method or the like, and then heated to form a resin. It is good to harden by plasticizing and cooling and solidifying again.

  It is also preferable to use a thermosetting resin that is cured by applying heat. The thermosetting resin is preferably a material that is a liquid precursor at room temperature and is cured by heat by being heated under pressure for several minutes to several hours and bonded to the current collector 2. As such a thermosetting resin material having heat-fusibility, for example, phenol resin, resorcinol resin, phenol-resorcinol resin, urea resin, polyester, silicone, polyisocyanate resin, urethane, epoxy resin, etc. may be used. it can. The curing conditions vary depending on the molecular weight of the monomer or oligomer, the composition, or the type of curing agent and catalyst, and can be designed from a relatively low temperature to a high temperature (room temperature to about 200 ° C.).

  Such a thermosetting resin is excellent in heat resistance, and since the state before curing is liquid at room temperature, the sealing material portion is easily formed by using a coating apparatus such as a dispenser or a screen printing machine. be able to. Therefore, it contributes to productivity improvement in battery manufacture.

  Furthermore, the sealing material 8 may contain insulating fine particles in the resin material described above (see FIG. 6). The insulating material 8 with insulating fine particles is improved in insulating properties when insulating fine particles enter during sealing. This is because not only the insulating property of the sealing material 8 as a whole is improved but also there are uneven coating of the sealing material 8 due to the presence of insulating fine particles therein, and there is a portion that becomes locally thin. By adding the fine particles, the fine particles are not applied thinner than the fine particles, and the adjacent current collectors can be reliably insulated from each other.

  Examples of such insulating fine particles include silicone particles and glass beads. The size of the insulating fine particles is not necessarily a sphere, but the size of the maximum portion is preferably smaller than the thickness between the current collectors. This is not preferable if the insulating fine particles are too large, because when the current collector 2 is laminated through the sealing material 8, the peripheral portions of the current collector are lifted or gaps are formed due to the fine particles. Because.

  Further, the sealing material 8 may have a multilayer structure. For example, in the case of a three-layer structure, nylon having a high melting point is used for the intermediate layer, and a three-layer structure using polypropylene for the outer layer is sandwiched between the intermediate layers. With such a three-layer structure, when the temperature of the outer layer polypropylene melts and a temperature lower than the melting point of nylon is applied, the polypropylene is welded to the current collector 2 and the intermediate layer nylon can melt. Absent.

  In particular, when only the sealing material 8 has such a three-layer structure, for example, when the bipolar battery 1 described later is manufactured, the sealing material 8 is melted too much when the sealing materials 8 are heat-sealed. Can be prevented.

  The magnitude | size of the sealing material 8 will not be specifically limited if it is a magnitude | size which can prevent the liquid leak between the electrical power collectors 2 as the sealing material 8. FIG. Therefore, it may be larger than the outer periphery of the current collector 2.

  Thus, the opening 15 provided in the sealing material 8 is sealed with the sealing material in the completed state of the bipolar battery 1.

  The sealing material 7 fills the opening 15 after injecting the electrolyte to prevent leakage of the electrolytic solution from the electrolyte. As the sealing material 7, for example, the above-described thermoplastic resin can also be used. When using a thermoplastic resin, for example, the resin is dissolved in advance by, for example, a hot melt method and adhered to either the upper or lower current collector of the opening 15, and after the electrolyte is injected, heat is applied to the resin, It can be sealed by cooling and solidifying. Further, a thermosetting resin may be used.

  When a thermosetting resin is used as the sealing material 7, after injecting the electrolyte, the resin is applied to the opening 15, and further, only the vicinity of the opening 15 is heated and pressed to cure the resin and thereby seal. be able to. The precursor of the thermosetting resin used at this time is preferably one having a high viscosity of 100 cP or more so as not to penetrate into the battery.

  When sealing, it is good to carry out under vacuum, and it is because it becomes possible to seal the inside of a battery without a gas by sealing under vacuum, and battery performance improves.

[Current collector]
The current collector 2 needs to be formed by laminating and stacking whatever shape it has, for example, aluminum, copper, titanium, nickel, stainless steel by thin film manufacturing technology such as spray coating. (SUS), which is formed by heating a current collector metal paste containing a metal powder, such as an alloy thereof, as a main component and containing a binder (resin) and a solvent, and formed of the metal powder and the binder. It has been made. In addition, these metal powders may be used alone or in combination of two or more, and moreover, different types of metal powders are laminated in multiple layers taking advantage of the characteristics of the manufacturing method. It may be a thing.

  The binder is not particularly limited. For example, a conventionally known resin binder material such as an epoxy resin can be used, and a conductive polymer material may be used.

  Although the thickness of the electrical power collector 2 is not specifically limited, Usually, it is about 1-100 micrometers.

  And the part which hits the opening part 15 of this electrical power collector is water-repellent and oil-repellent (refer FIG.7 (b)). As the water / oil repellent treatment, for example, fluorine resin coating or polyolefin resin coating is preferable.

  Examples of the fluororesin include PTFE (tetrafluoroethylene resin), PFA (copolymer of tetrafluoroethylene (TFE) and perfluoroalkoxyethylene), FEP (perfluoroethylene-propene copolymer), and the like.

  Examples of the polyolefin resin include a polyethylene film and a polypropylene film.

  In addition, examples of the water / oil repellent treatment include application of silicone resin, paraffin, and the like.

  By this water / oil repellent treatment, the electrolyte remaining in the opening 15 after being injected from the opening 15 can be easily removed by, for example, blowing a gas such as air or nitrogen gas.

  This is because the portion of the opening 15 must be sufficiently wiped away after the injection so that no electrolyte remains. If the electrolyte remains in the opening 15, the opening 15 is sealed by the sealing material 7 after the injection. When sealing the battery, a conductive electrolyte may remain between the sealing material 7 and the current collector, which may cause a liquid junction (short circuit). Thus, the opening 15 can be reliably sealed without remaining.

  In particular, polyolefin resin repels the electrolyte, so the electrolyte remaining in the injection port can be easily removed after injection, and the chemical stability is extremely high. There is no.

[Positive electrode (positive electrode active material layer)]
The positive electrode includes a positive electrode active material. In particular, it is preferable to use a lithium-transition metal composite oxide as the positive electrode active material. Such a positive electrode and substance can constitute a battery having excellent capacity and output characteristics.

  In addition to the above, the positive electrode active material may contain an electrolyte, a lithium salt, a conductive auxiliary agent, and the like in order to enhance ion conductivity. In particular, it is desirable that at least one of the positive electrode and the negative electrode contains an electrolyte, preferably a solid polymer electrolyte. However, in order to further improve the battery characteristics of the bipolar battery 1, it is preferable to contain both. .

Specifically, a composite oxide of transition metal and lithium, which is also used in a solution-type lithium ion battery, can be used as the positive electrode active material. For example, Li · Co-based composite oxide such as LiCoO _2, Li · Ni-based composite oxide such as LiNiO _2, Li · Mn-based composite oxide such as spinel LiMn ₂ O _4, Li · Fe-based composite, such as LiFeO ₂ An oxide etc. are mentioned. In addition, transition metal and lithium phosphate compounds and sulfate compounds such as LiFePO ₄ ; transition metal oxides and sulfides such as V ₂ O ₅ , MnO ₂ , TiS ₂ , MoS ₂ , and MoO ₃ ; PbO ₂ , AgO, NiOOH etc. are mentioned.

The particle diameter of the positive electrode active material is not limited as long as the positive electrode material can be formed into a paste by spray coating and the like, but in order to reduce the electrode resistance of the bipolar battery 1, the electrolyte is not a solid solution. What is smaller than the generally used particle size used in the type of lithium ion battery may be used. Specifically, the average particle diameter of the positive electrode active material is preferably 10 to 0.1 μm.
Examples of the conductive assistant include acetylene black, carbon black, and graphite. However, it is not necessarily limited to these.

  The amount of the positive electrode active material, electrolyte (preferably solid polymer electrolyte), lithium salt, and conductive additive in the positive electrode is determined in consideration of the intended use of the battery (output priority, energy priority, etc.) and ion conductivity. Should. For example, if the amount of the electrolyte in the positive electrode, particularly the solid polymer electrolyte, is too small, the ionic conduction resistance and the ionic diffusion resistance in the active material layer will increase, and the battery performance will deteriorate. On the other hand, when the amount of the electrolyte in the positive electrode, particularly the solid polymer electrolyte, is too large, the energy density of the battery decreases. Therefore, in consideration of these factors, the solid polymer electrolytic mass meeting the purpose is determined.

  The thickness of the positive electrode is not particularly limited, and should be determined in consideration of the intended use of the battery (emphasis on output, emphasis on energy, etc.) and ion conductivity, as described for the blending amount. The thickness of a general positive electrode active material layer is about 1 to 500 μm.

[Negative electrode (negative electrode active material layer)]
The negative electrode includes a negative electrode active material. Specifically, metal oxide, lithium-metal composite oxide metal, carbon and the like are preferable. More preferred are carbon, transition metal oxide, and lithium-transition metal composite oxide. Among these, carbon or lithium-transition metal composite oxide can increase the capacity and output of the battery. Furthermore, titanium oxide, lithium-titanium composite oxide, carbon and the like can also be used.

  And these may be used individually by 1 type and may use 2 or more types together.

[Electrolyte layer]
The electrolyte layer 5 used here is one in which a fluid electrolyte (electrolytic solution) is held by a spacer. The electrolyte layer 5 forms the electrolyte layer 5 by injecting an electrolyte from the opening 15 as in the manufacturing method described later.

  As the electrolyte having fluidity, for example, a gel electrolyte in which an electrolytic solution is held in a polymer skeleton by about several weight% to 99 weight% is preferable.

  As such an electrolyte, a polymer gel electrolyte is particularly preferable. As the polymer gel electrolyte, a solid polymer electrolyte having ion conductivity and an electrolyte solution usually used in a lithium ion battery, or a polymer skeleton having no lithium ion conductivity, What hold | maintained the same electrolyte solution is also contained.

  As for the polymer gel electrolyte, any polymer electrolyte containing a polymer skeleton other than the one made of 100% polymer electrolyte is a polymer gel electrolyte. Among these, a polymer gel electrolyte in which the ratio (mass ratio) of the electrolytic solution to the polymer is about 20:80 to 98: 2 is preferable in terms of both fluidity due to the electrolyte and performance as the electrolyte.

  As the polymer skeleton, either a thermosetting polymer or a thermoplastic polymer can be used.

  Specific polymer skeletons include, for example, a polymer having polyethylene oxide in the main chain or side chain (PEO), polyacrylonitrile (PAN), polymethacrylic ester, polyvinylidene fluoride (PVDF), polyvinylidene fluoride and hexafluoro. A copolymer of propylene (PVDF-HFP), polymethyl methacrylate (PMMA), or the like is used. However, it is not necessarily limited to these.

As an electrolytic solution contained in the polymer gel electrolyte (electrolytic salt and plasticizer) may be those usually used in a lithium ion battery, for _{example, LiPF 6, LiBF 4, LiClO} 4, LiAsF 6, LiTaF 6, LiAlCl ₄ , inorganic acid anion salts such as Li ₂ B ₁₀ Cl ₁₀ , organic acid anion salts such as LiCF ₃ SO ₃ , Li (CF ₃ SO ₂ ) ₂ N, Li (C ₂ F ₅ SO ₂ ) ₂ N At least one lithium salt (electrolyte salt) selected from among, cyclic carbonates such as propylene carbonate and ethylene carbonate; chain carbonates such as dimethyl carbonate, methyl ethyl carbonate, and diethyl carbonate; tetrahydrofuran, 2-methyl Tetrahydrofuran, 1,4-dioxane, 1, -Ethers such as dimethoxyethane and 1,2-dibutoxyethane; Lactones such as γ-butyrolactone; Nitriles such as acetonitrile; Esters such as methyl propionate; Amides such as dimethylformamide; Methyl acetate and methyl formate Those using an organic solvent (plasticizer) such as an aprotic solvent in which one or two or more selected from the above are mixed can be used. However, it is not necessarily limited to these.

  Such a polymer gel electrolyte is contained in the positive electrode and / or the negative electrode as well as the electrolyte layer 5 constituting the battery by being injected from the opening 15.

  The thickness of the electrolyte layer 5 is not particularly limited. However, in order to obtain a compact bipolar battery, it is preferable to make it as thin as possible within a range in which the function as the electrolyte layer 5 can be secured. The thickness of the electrolyte layer 5 using a general solid polymer electrolyte is about 10 to 100 μm. However, the shape of the electrolyte layer 5 can be easily formed so as to cover the upper surface of the electrode (positive electrode or negative electrode) as well as the outer peripheral portion of the side by taking advantage of the manufacturing method. However, it is not always necessary to have a substantially constant thickness.

  In order to keep such a thickness constant, in this embodiment, a nonwoven fabric is interposed as a spacer 18 between the positive electrode and the negative electrode in the manufacturing stage (see FIG. 6C). The material of the nonwoven fabric is not particularly limited. For example, a polyamide nonwoven fabric, a polyethylene nonwoven fabric, a polypropylene nonwoven fabric, a polyimide nonwoven fabric, a polyester nonwoven fabric, and an aramid nonwoven fabric so as not to disturb the electrolyte injection from the opening 15. Etc. are preferable. And this nonwoven fabric functions as a separator after completion as a battery (after electrolyte injection).

  In addition, a microporous membrane film that is an existing separator for lithium ion batteries having pores by stretching the film may be used, and a polyethylene, polypropylene, polyimide film, or a laminate of these may be used. it can.

[Battery exterior material (battery case)]
The bipolar battery 1 accommodates the entire battery stack including the bipolar battery body in a battery exterior material or battery case in order to prevent external impact and environmental degradation.

  From the viewpoint of weight reduction, conventional battery cases have been conventionally used such as polymer-metal composite laminate films and aluminum laminate packs in which metals (including alloys) such as aluminum, stainless steel, nickel, and copper are coated with an insulator such as polypropylene film. It is preferable that the battery stack is housed and sealed by joining a part or the whole of the outer peripheral part by heat fusion using a known battery exterior material.

  In addition, the use of polymer-metal composite laminate films and aluminum laminate packs with excellent thermal conductivity allows heat to be efficiently transferred from the heat source of the automobile and the inside of the battery to be quickly heated to the battery operating temperature. preferable.

  FIG. 10 is a drawing showing an external appearance when the bipolar battery 1 is configured as a battery 20 using an aluminum laminate pack. In this battery 20, a positive electrode terminal plate and a negative electrode terminal plate are provided on the current collector 2 at the end, and leads are further attached to form electrodes 23 and 24.

[Production method]
Next, a method for manufacturing the bipolar battery 1 will be described.

  FIGS. 11-14 is explanatory drawing for demonstrating the manufacturing method of the bipolar battery 1 to which this invention is applied. 11A is a plan view showing one current collector, FIG. 11B is a cross-sectional view taken along line BB in FIG. 11A, and FIG. 11C shows a state where a spacer is placed. It is sectional drawing shown. 12A is a cross-sectional view showing a cross section at a position along the line DD in FIG. 11A in a state where the current collectors are stacked, and FIG. 12B is a state where the current collectors are stacked. It is sectional drawing which shows the cross section in the position which follows the EE line | wire of Fig.11 (a).

  First, as shown in FIGS. 11A and 11B, the positive electrode 3 is formed on the first surface of the current collector, and the negative electrode 4 is formed on the second surface opposite to the first surface. For this, the above-mentioned materials for the positive electrode active material and the negative electrode active material are mixed, applied as a slurry to one side of the current collector 2 and dried. At this time, the positive electrode and the negative electrode are not formed on the outer peripheral portion of the current collector, and a non-forming region exists. As a result, a bipolar electrode in which the positive electrode 3 and the negative electrode 4 are formed on one current collector 2 is completed.

  Subsequently, a sealing material 8 is formed in a region where the positive electrode 3 is not formed on the positive electrode 3 side of the current collector 2. The sealing material 8 shown in FIG. 11 shows a material containing insulating fine particles 81.

  Here, the sealing material 8 is formed on the positive electrode 3 side because, in an ordinary lithium ion battery, the positive electrode 3 is formed smaller than the negative electrode 4 in order to prevent lithium dendride, and therefore the positive electrode 3 is not formed in the positive electrode side peripheral portion. This is because the area is wide and the sealing material can be easily applied. Note that the sealing material 8 may be formed on the negative electrode side.

  A portion that comes into contact with the opening 15 of the current collector 2 is subjected to water / oil repellent finish. This water / oil repellent treatment may be performed before or after the sealing material 8 is formed.

  For example, before the formation of the sealing material, the portion other than the portion corresponding to the opening may be masked with a masking film or the like, and a fluorine resin or a polyolefin resin may be spray applied, and the masking film may be peeled off each time. In addition, before the formation of the positive electrode and the negative electrode, a fluororesin or polyolefin resin is applied to the entire current collector, and then the fluororesin applied to the region where the positive electrode, the negative electrode, and the sealing material 8 are formed. Alternatively, the polyolefin resin may be peeled off to expose the surface of the current collector of these portions, while the fluororesin or the polyolefin resin may be left only in the portion corresponding to the opening 15.

  In addition, after formation of the sealing material, the portion other than the portion corresponding to the opening may be masked with a masking film and sprayed, or only the portion corresponding to the opening may be applied by brushing (brush coating). In case the masking film is not necessary).

  Then, as shown in FIG.11 (c), the nonwoven fabric is put as the spacer 18 on the positive electrode side of the electrical power collector 2 in which the sealing material 8 was formed. At this point, a bipolar electrode member 10 to be laminated is completed.

  Although not described in detail, a current collector corresponding to the outermost layer of the battery is prepared in the same manner as described above, in which only the positive electrode is formed and in which only the negative electrode is formed. However, it is not necessary to form a sealing material for the current collector formed with only the negative electrode.

  The bipolar electrode member 10 formed in this way is easy to handle because it is entirely made of a solid material as a whole.

  Thereafter, as shown in FIG. 12, a plurality of current collectors 2 on which the sealing material 8 is formed are stacked. FIG. 12A shows a portion without the opening 15, and FIG. 12B shows a portion with the opening 15. As shown in the drawing, by stacking a plurality of current collectors on which the sealing material 8 is formed, an unformed portion of the sealing material becomes the opening 15. The current collector portion of the opening 15 is provided with a water / oil repellent finish 9.

  Thereafter, as shown in FIG. 13, the entire stacked current collector (referred to as battery element 11) is pressurized by a pressurizing device 61 while being warmed from both sides. The temperature at this time is a temperature at which the sealing material 8 is thermally welded to the current collector. Therefore, the heating temperature is appropriately selected depending on the sealing material 8 used.

  At this stage, the battery element 11 containing no electrolyte is completed.

  Thereafter, as shown in FIG. 14, one side of the battery element 11 having the opening 15 is immersed in the electrolyte solution 19, and vacuuming is performed from the opening 15 on the other side. As a result, the electrolyte is sucked into the battery element 11, and the electrolyte is injected from the opening 15 between the positive electrode and the negative electrode, and the electrolyte layer 5 is formed in the battery element 11.

  In addition to the injection method shown in FIG. 14, the electrolyte may be injected directly by inserting a tube or nozzle into the opening 15 as already described.

  After the injection of the electrolyte, as shown in FIG. 15, the electrode lead 62 is simply connected to the outermost current collector of the battery element 11 to perform the initial charge. This discharges the gas generated during the initial charging to the outside of the battery.

  Usually, in a lithium ion secondary battery, gas is generated from the inside due to air that has entered during the manufacturing process or chemical changes accompanying charging, etc., but most of such gas is generated at the time of initial charging. Therefore, by performing the first charge before closing the opening 15, such gas can be released from the opening 15.

  Thereby, the battery which has the high reliability without the influence by internal gas as a battery can be manufactured.

  Finally, a resin material 17 that becomes the sealing material 7 is embedded in the opening 15 into which the electrolyte has been injected, for example, by a hot melt method and sealed.

  As a result, the bipolar battery 1 is completed, and thereafter, an electrode terminal plate may be attached and sealed in various packages.

[Experimental example]
Next, an experimental example in which an actual battery is manufactured will be described.

<Formation of electrode>
(1) Formation of positive electrode The following materials were mixed at a predetermined ratio to prepare a positive electrode slurry.

As a positive electrode active material, 85% by mass of LiMn ₂ O ₄ , 5% by mass of acetylene black as a conductive auxiliary agent, 10% by mass of PVDF as a binder, and an appropriate amount of NMP as a slurry viscosity adjusting solvent are mixed to produce a positive electrode slurry. did.

  The positive electrode slurry was applied to one side of a SUS foil (thickness 20 μm) as a current collector and dried to form a 30 μm positive electrode.

(2) Formation of negative electrode The following materials were mixed at a predetermined ratio to prepare a negative electrode slurry.

  A negative electrode slurry was prepared by adding 90% by mass of hard carbon as a negative electrode active material, 10% by mass of PVDF as a binder, and mixing an appropriate amount of NMP as a slurry viscosity adjusting solvent.

  The negative electrode slurry was applied to the opposite surface of the SUS foil just coated with the positive electrode and dried to form a 30 μm negative electrode.

  As a result, a positive electrode and a negative electrode were formed on both surfaces of the SUS foil as a current collector, thereby forming a bipolar electrode.

  These bipolar electrodes were cut out to 130 × 80 (mm), and the outer peripheral part of both the positive electrode and the negative electrode was peeled off by 10 mm to expose the SUS surface as a current collector.

<Formation of sealing material>
A precursor serving as a sealing material was applied to a portion where the positive electrode was not applied to the periphery of the positive electrode side of the bipolar electrode using a screen printer, leaving a non-coated portion of the sealing material, that is, a portion corresponding to the opening. The precursor used as the sealing material is a one-component epoxy resin in which an epoxy resin as a main material and a curing agent are mixed in a predetermined ratio in advance and further containing an additive, and has a thickness of about 0.1 mm. It was made to become. This thickness is crushed to a thickness similar to the distance between the electrodes by being pressed in a subsequent step.

<Bipolar stack formation>
A spacer (aramid nonwoven fabric 20 μm) was placed on the positive electrode of the bipolar electrode created above to form a bipolar stack in which five layers were laminated.

<Curing sealant>
The bipolar stack prepared as described above was hot-pressed with a hot press machine at a surface pressure of 3 kg / cm 2 and 90 ° C. for 1 hour to prepare a battery element having an opening (electrolyte injection port).

<Injection of electrolyte>
The opening was dipped in the electrolyte and placed under reduced pressure (vacuum), or the electrolyte (PC + EC 1M-LiPF ₆ ) was injected by vacuuming <Formation of post-injection seal member>
After injection of the electrolyte, the opening was filled with polyethylene by a hot melt method and cooled to close the opening and seal the electrolyte. Thereby, the bipolar battery 1 was completed.
Using the above as the basic manufacturing process, batteries of the following examples were prepared.

Example 1
A battery element having two openings on one side as shown in FIG. 4 was manufactured, the whole was immersed in an electrolyte solution, and the electrolyte was injected under reduced pressure to complete the bipolar battery 1. At this time, it took about 10 minutes for the electrolyte to completely penetrate into the battery.

(Examples 2 to 4)
At the time of forming the precursor of the sealing material, two uncoated portions (openings) were formed on opposite sides. As shown in FIG. 1, two are formed on the short side as shown in Example 2, and as shown in FIG. 2, two are formed on the long side as shown in Example 3 and FIG. Example 4 was formed at the diagonal part.

  According to the manufacturing method in the above-described embodiment, the electrolyte is injected by immersing only one side (or corner) in the electrolyte solution and placing the whole under reduced pressure, so that the electrolyte is released from the open opening. A vacuum was drawn.

  At this time, it took 2.5 minutes in Example 2, 3 minutes in Example 3, and 4 minutes in Example 4 for the electrolyte to completely penetrate into the battery.

  The rest is the same as the basic manufacturing process.

(Example 5)
At the time of forming the precursor of the sealing material, 20% volume ratio of 10 μm silicone particles was added to the precursor of the sealing material, stirred with a homogenizer, and then two uncoated portions (opening) using a dispenser as shown in FIG. Part).

  The rest is the same as the basic manufacturing process.

(Example 6)
Fluorine processing was performed by applying PTFE resin to the SUS exposed portion in the periphery of the electrode. And the process of blowing off the electrolyte adhering to an opening part was added by blowing the vicinity of an opening part with the wind pressure using nitrogen gas at the time of injection | pouring of electrolyte. This eliminates the electrolyte in the opening and eliminates the need for wiping the electrolyte with a waste cloth.

  The rest is the same as the basic manufacturing process.

(Example 7)
A 15 μm polyethylene film is fused in advance to the sealant precursor-uncoated portion, and after the electrolyte is injected, the electrolyte adhering to the opening is blown off by blowing the vicinity of the opening with a wind pressure using nitrogen gas. A process was added. This eliminates the electrolyte in the opening and eliminates the need for wiping the electrolyte with a waste cloth.

  The rest is the same as the basic manufacturing process.

(Example 8)
At the time of electrolyte injection, 10% by weight of a monomer solution (copolymer of polyethylene oxide and polypropylene oxide) having an average molecular weight of 7500 to 9000 which is a precursor of an ion conductive polymer matrix as an electrolyte, and PC + EC (1: 1) 90 as an electrolyte A pregel solution consisting of% by weight, 1.0 M LiBF ₄ , and a polymerization initiator (perhexyl PV) was used and injected from the opening. Thereafter, the opening was filled with polyethylene by a hot melt method and cooled. Furthermore, after that, the whole was heated in an oven (90 ° C., 1 hr) and thermally cured.

  The rest is the same as the basic manufacturing process.

Example 9
At the time of injecting the electrolyte, a pregel solution comprising 95 parts by weight of an electrolyte as an electrolyte and 5 parts by weight of a PVDF-HFP copolymer having a HFP ratio of 10% by weight and plasticized by applying a temperature of 90 ° C. Used and cooled after injection, gelled inside the battery element.

  The rest is the same as the basic manufacturing process.

(Example 10)
・ After the electrolyte injection, before sealing the opening with the sealing material, the opening is turned up and the initial charge (up to 21V with 0.5C charge) is performed, then the pressure is reduced in that state, and the gas generated inside Was removed. Thereafter, the opening was filled with a sealing material and sealed.

  The rest is the same as the basic manufacturing process.

(Example 11)
As shown in FIG. 5, the sealing material 8 was formed so that the openings 15 were at different positions in the stacking direction.

  The rest is the same as the basic manufacturing process.

(Example 12)
As shown in FIG. 6, the sealing material 8 was formed so that the opening 15 was positioned at the corner. And instead of impregnating the electrolyte with vacuum, tubes were inserted into each layer and injected directly.

  The rest is the same as the basic manufacturing process.

(Example 13)
As shown in FIG. 7, the size of the spacer 18 is made about 10 mm longer and wider than the current collector 2, and the spacer 18 is disposed on the bipolar electrode when forming the bipolar stack, and the same is once again formed thereon. The sealing material 8 was apply | coated to the site | part using the dispenser. This was repeated 5 layers to complete a bipolar stack.

  The rest is the same as the basic manufacturing process.

(Example 14)
As shown in FIG. 9B, the size of the spacer 18 is about 10 mm longer and wider than the current collector 2, and a protruding portion 180 is provided in which the corner portion of the spacer 18 protrudes from other portions. The projecting portion 180 was formed integrally from the beginning as the shape of the spacer 18. Then, the spacer 18 was disposed on the bipolar electrode, and the sealing material 18 was applied using a dispenser so that the opening 15 was located at the position where the protruding portion 180 was located. This was repeated 5 layers to complete a bipolar stack.

  Then, a tube for feeding the electrolyte was inserted into each layer so as to open the opening 15 with the overhanging portion 180, and the electrolyte was directly injected.

  The rest is the same as the basic manufacturing process.

(Comparative example)
Polypropylene separator 50 μm, 10% by weight monomer solution (copolymer of polyethylene oxide and polypropylene oxide) having an average molecular weight of 7500 to 9000 which is a precursor of an ion conductive polymer matrix, and PC + EC (1: 1) 90 as an electrolyte A pregel solution composed of% by weight, 1.0 M LiBF ₄ and a polymerization initiator (BDK) was immersed, sandwiched between quartz glass substrates and irradiated with ultraviolet rays for 15 minutes to crosslink the precursor, thereby obtaining a polymer electrolyte layer. This electrolyte was alternately laminated with bipolar electrodes without a sealing structure to complete a five-layer bipolar battery.

<Evaluation 1>
First, it charged to 21V with each battery of Examples 1-10 and a comparative example. The charge current was a constant current and constant voltage (CCCV) charge of 0.5 C for 2 hours on a capacity basis estimated from the coating weight of the positive electrode.

Thereafter, each battery was charged with a constant current (CC) at a current of 1 C, then discharged with a constant current (CC), and this was regarded as one cycle, and this cycle was performed at 25 ° C. for 50 cycles. (Cycle test)
-In the battery of the comparative example that does not have an electrolyte seal layer, in the middle of the 24th cycle, the electrolyte oozes out of the single cell layer, contacts with the electrolyte of another single cell layer, and a liquid junction occurs, resulting in a remarkable battery voltage. Declined.

  The batteries of Examples 1 to 10 having the sealing material maintained a voltage even when exceeding 50 cycles without causing a short circuit, and exhibited good cycle characteristics.

  Therefore, it was found that the battery having the seal structure in each example has high seal reliability.

<Evaluation 2>
Comparing the electrolyte injection times of the battery of Example 1 and the batteries of Examples 2 to 4, Example 3 was the earliest 2 minutes, Example 2 was 2.5 minutes, Example 4 was 4 minutes, Example 1 Was 10 minutes. Therefore, as in Examples 2 to 4, it was found that the injection time was shortened by providing the opening at the opposite position. The determination of the completion of injection was performed by measuring the time during which the volume of electrolyte that filled all the voids in the battery penetrated into the battery.

  Furthermore, the electrolyte injection time of Example 12 and Example 14 was measured. As a result, Example 12 was 30 seconds and Example 14 was 9 seconds. This is faster than Examples 1 to 4 because the electrolyte can be directly fed into each layer.

  Further, in Example 14, the spacer 15 can be held and the opening 15 can be opened, so that the tube and the nozzle are easier to insert than in Example 12, and thus the dispensing time can be shortened.

<Evaluation 3>
Both sides of the battery of Example 1 and the battery of Example 5 were pressed with a press machine to reproduce a state in which abnormal pressure was applied to the battery. The applied pressure applied a load of 3 tons (29 kg / cm ² ) assuming an abnormal time.

  In the battery of Example 1, the cell was short-circuited inside and the voltage was reduced, but in the battery of Example 5, such a decrease in voltage was not observed.

  Therefore, it was found that the insulating particles dispersed in the sealing member have higher insulating properties, sealing properties, and impact resistance for each unit cell.

Furthermore, in Example 13 and Example 14 as well, both surfaces of the battery were pressed with a press machine and a load of 3 tons (29 kg / cm ² ) was applied assuming an abnormal condition, but neither battery caused a short circuit. It was.

  Therefore, it has been found that the spacer 18 having a short portion of insulation has higher end insulation.

<Evaluation 4>
The battery of Example 1 and the battery of Example 10 were further subjected to a cycle test of 200 cycles at 60 ° C. under the conditions of Evaluation 1. Table 1 shows the discharge capacity after 200 cycles when the initial discharge capacity is 100%.

  It was found that the battery of Example 10 to which a degassing step was added had a larger discharge capacity. This is presumably because the battery of Example 1 was not degassed so that bubbles remained in the battery and the battery deteriorated faster.

<Evaluation 5>
After sealing the opening part of each battery of Examples 1 to 14, the thickness in the vicinity of the opening part was measured. The results are shown in Table 2.

  In Example 11 in which the opening 15 is located at a different position in the stacking direction when the sealing material 8 is formed, the thickness in the vicinity of the opening is thinner than that in the other examples, and this thickness is almost the same as the thickness in the center of the battery. It was equivalent.

  Therefore, it was found that the form of Example 11 is small in volume and the volume density of the battery is improved.

  As described above, the bipolar battery according to the present embodiment is provided with a sealing material for each of the plurality of single cells sandwiched between the current collectors, and after stacking the current collectors, the electrolyte can be injected by the injection method. Since a bipolar battery in which a plurality of current collectors (bipolar electrodes) are stacked can be manufactured without retaining a characteristic electrolyte component, the manufacturing method can be facilitated and the manufacturing cost can be reduced. Moreover, it was confirmed that such a structure also has a sufficient sealing property as can be seen from the above-described embodiments.

  The bipolar battery and the method for manufacturing the same according to the present invention have been described above. Hereinafter, an assembled battery using the bipolar battery and an automobile equipped with the battery will be described.

  For example, as shown in FIG. 10, the bipolar battery described above is assembled as a battery by a laminate package or the like, but a plurality of them can be connected in parallel or in series to form a battery pack.

  FIG. 17 is a perspective view illustrating an example of an assembled battery.

  As shown in the figure, this assembled battery 50 is formed by arranging a plurality of batteries 20 arranged so as to be seated vertically and arranged horizontally, and connected to terminal plates 23 and 24 of each battery 20 by conductive bars 51 and 52. ing.

  In this way, by forming an assembled battery, high capacity and high output can be obtained, and since the reliability of each battery 20 is high, long-term reliability as an assembled battery can be improved.

  In addition, it is also possible to provide a larger assembled battery or a battery module by connecting a plurality of such assembled batteries 50 in series and / or in parallel.

  And such an assembled battery 50 and an assembled battery module become an assembled battery module optimal for vehicle-mounted use, such as an electric vehicle and a hybrid vehicle, for example.

  For reference, FIG. 18 shows a schematic diagram of an automobile 100 equipped with an assembled battery module 60 in which a plurality of assembled batteries 50 are connected. This automobile is an automobile that uses the assembled battery module 60 as a power source for a motor.

  An automobile using the assembled battery module 60 as a motor power source is an automobile whose wheels are driven by a motor, such as an electric vehicle and a hybrid vehicle. By using the assembled battery or battery module by the bipolar battery to which the present invention is applied to these automobiles, it becomes possible to perform very fine control such as charging control for each single cell, and improve the performance of an electric vehicle, for example, once. It can be expected that the travel distance per charge of the battery will be improved and the life of the vehicle battery will be improved.

  The present invention is suitable for a lithium ion secondary battery using a bipolar electrode. This bipolar battery is suitable as a power source for a vehicle motor.

It is explanatory drawing for demonstrating the structure of the bipolar battery to which this invention is applied, (a) is a top view, (b) is sectional drawing which follows the BB line in (a). It is a top view of the bipolar battery for demonstrating the example of the other position of an opening part. It is a top view of the bipolar battery for demonstrating the example of the other position of an opening part. It is drawing which shows the example at the time of providing the opening part in one side, (a) is a top view of a bipolar battery, (b) is sectional drawing which follows the B1-B2 line | wire of (a). It is a top view of the bipolar battery for demonstrating the example of the other position of an opening part. Furthermore, it is explanatory drawing for demonstrating the bipolar battery which changed the position of the opening part 15. FIG. It is explanatory drawing for demonstrating another bipolar battery. It is sectional drawing for demonstrating the other form of a spacer. It is a top view for demonstrating other form of a spacer. It is a perspective view which shows the external appearance of the battery which carried out the lamination package. It is explanatory drawing for demonstrating the manufacturing method of a bipolar battery, (a) is a top view which shows the one electrical power collector, (b) is sectional drawing which follows the BB line of (a), (c) FIG. 3 is a cross-sectional view showing a state where a spacer is placed. It is explanatory drawing for demonstrating the manufacturing method of the bipolar battery following FIG. 11, (a) is a cross section which shows the cross section in the position which follows the DD line | wire of Fig.6 (a) in the state which laminated | stacked the electrical power collector. FIG. 4B is a cross-sectional view showing a cross section at a position along the line E-E in FIG. It is explanatory drawing for demonstrating the manufacturing method of the bipolar battery following FIG. It is explanatory drawing for demonstrating the manufacturing method of the bipolar battery following FIG.

It is explanatory drawing for demonstrating the manufacturing method of the bipolar battery following FIG. FIG. 16 is an explanatory diagram for explaining a manufacturing method of the bipolar battery following FIG. 15. It is a perspective view which shows an example of an assembled battery. It is the schematic of the motor vehicle carrying the assembled battery module which connected more assembled batteries.

Explanation of symbols

1 ... Bipolar battery,
7: Sealing material,
8 ... sealing material,
10 ... Battery element,
15 ... opening,
18 ... spacer,
20 ... Battery,
50 ... Battery 100 ... Automobile.

Claims (3)

A current collector provided with a positive electrode on a first surface and a negative electrode on a second surface facing the first surface;
An electrolyte layer interposed between a plurality of the current collectors laminated so that the positive electrode and the negative electrode face each other;
Between the current collectors, disposed so as to surround the positive electrode, the electrolyte layer, and the negative electrode, and in close contact with the non-formation sites of the positive electrode and the negative electrode on the outer periphery of the current collector, and partially A sealing material having an opening;
A sealing material that fills the opening of the sealing material;
I have a,
The bipolar battery , wherein the opening is provided at a different position in the stacking direction of the current collector. The bipolar battery according to claim 1 , wherein a surface of the current collector in contact with the opening is water / oil repellent. The electrolyte layer has the positive electrode and the interposed between the anode and widely than the current collector, the spacer enclosed inner becomes the electrolyte layer Rukoto is impregnated with the electrolyte in the sealing material,
The spacer bipolar battery according to claim 1 or 2, wherein a projecting portion to the position of the opening.

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