JP4929587B2 - Bipolar battery, manufacturing method thereof, and assembled battery - Google Patents

Description

The present invention, a bipolar battery and a manufacturing method thereof, relates to a set batteries comprising the bipolar battery.

  The bipolar battery is a lithium ion secondary battery that is stacked so that a plurality of single cells are connected in series.

In such a battery in which a plurality of unit cells are stacked, a voltage detection tab is pulled out from each unit cell for each unit cell in order to measure the voltage of each unit cell. Since such a voltage detection tab is taken out from each positive electrode and negative electrode of the stacked unit cells, adjacent electrodes (positive electrode and negative electrode, or between positive electrodes and negative electrodes) do not come into contact with each other and are not short-circuited. The position for attaching the voltage detection tab is arranged so that the cells are different from each other (see Patent Document 1).
JP 2004-87238 A

  However, when the voltage detection tab is provided for each unit cell and the installation position is arranged at a different position for each stacked unit cell, the same shape is used for the stacked unit cells except for the voltage detection tab. Nevertheless, it has been necessary to manufacture electrodes or current collectors having different shapes for each unit cell in order to form the voltage detection tab. For this reason, there existed a problem that manufacturing efficiency was bad and manufacturing cost was complicated.

Accordingly, an object of the present invention is to provide a bipolar battery capable of detecting a voltage for each unit cell and a method for manufacturing the same while maintaining the same shape of the members constituting the unit cells to be stacked. Another object of the present invention is to provide a battery pack that can reduce the manufacturing cost.

The present invention provides a bipolar electrode in which a positive electrode is formed on a first surface of a current collector and a negative electrode is formed on a second surface opposite to the first surface, and an electrolyte layer is interposed between the positive electrode and the negative electrode. A bipolar battery in which a plurality of the bipolar electrodes having the same shape are stacked, and the conductive line electrically connected to the end face of the current collector matches the position of the end face of the current collector And a support member that is insulated from and supported by the other conductive wires.

Further, the present invention includes a positive electrode is formed on the first surface of the current collector, and forming a bipolar electrode negative electrode formed on the second surface facing the first surface, the bipolar electrodes of the same shape A step of stacking an electrolyte layer between the positive electrode and the negative electrode, a step of aligning end surfaces of the current collector of the stacked bipolar battery, and anisotropy of the aligned end surfaces Electrically connecting the conductive wires that are insulated from each other and supported by the support member so as to coincide with the position of the end face of the current collector through the conductive conductive material It is a manufacturing method of a battery.

  The present invention is also an assembled battery in which a plurality of the bipolar batteries are connected in series and / or in parallel.

  According to the present invention, since the conductive wire is connected to the current collector end faces of the plurality of stacked bipolar electrodes, there is no need to provide a voltage detection tab on each of the current collector and the bipolar electrode. For this reason, the shape of the current collector, the positive electrode, the negative electrode, and the like, which are members constituting the bipolar electrode, may be the same, improving the manufacturing efficiency of each member and reducing the manufacturing cost.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  1A and 1B are diagrams for explaining a bipolar electrode used in the present invention, wherein FIG. 1A is a plan view and FIG. 1B is a cross-sectional view taken along line aa. 2A and 2B are diagrams for explaining an embodiment of a bipolar battery according to the present invention using the bipolar electrode, wherein FIG. 2A is a plan view and FIG. 2B is a cross section taken along line aa in FIG. It is a figure (however, it is sectional drawing after the side surface cutting mentioned later). FIG. 3 is a schematic perspective view of the bipolar battery according to the present embodiment.

  First, with reference to FIG. 1, the bipolar electrode which comprises the bipolar battery of this invention is demonstrated.

  The bipolar electrode 14 includes a current collector 12 having a positive electrode 11 formed on a first surface and a negative electrode 13 formed on a second surface opposite to the first surface.

  In this bipolar electrode 14, a sealing material 16 used when manufacturing a bipolar battery is arranged in advance so as to surround the electrode on one surface side (the positive electrode 11 side in the figure) of the bipolar electrode 14 as shown. Yes. The sealing material 16 may be inserted when the bipolar electrode 14 is laminated.

  As shown in FIG. 2, the basic structure of the bipolar battery 1 is a structure in which a plurality of separators 15 each having a bipolar electrode 14 serving as an electrolyte layer are interposed between a positive electrode 11 and a negative electrode 13.

  Thus, a single cell is constituted by the positive electrode 11 of one bipolar electrode 14 and the negative electrode 13 of the adjacent bipolar electrode 14 with the separator 15 interposed therebetween, and such a single cell is connected in series by the current collector 12. Connected structure.

  In this way, the bipolar electrode 14 is an electrode and connects the single cells in series. For this reason, it is not necessary to interpose another connection member for connecting the cells in series. Therefore, there is no reduction in output due to resistance components such as connecting members. Further, since there is no connection portion, the battery module can be reduced in size. Furthermore, the energy density of the entire battery module is improved by the absence of the connection portion.

  It should be noted that the outermost current collectors 12a and 12b are formed with only one of the positive electrode 11 and the negative electrode 13, and a terminal plate serving as an electrode of the entire battery is laminated and connected as it is. In the figure, only the negative electrode 13 is formed on the current collector 12a side, and only the positive electrode 11 is formed on the current collector 12b side.

  In the bipolar battery 1 in which a plurality of bipolar electrodes 14 are laminated in this way, at least one active material layer of the positive electrode 11 or the negative electrode 13 is impregnated with a solid polymer electrolyte. Thus, by filling the space between the active materials in the active material layer with the polymer solid electrolyte, the ion conduction in the active material layer becomes smooth, and the output of the entire bipolar battery can be improved. The separator 15 is also impregnated with a polymer solid electrolyte (details will be described later).

  Each unit cell is provided with a sealing material 16 between its outer peripheral portion, the current collector 12 and the current collector 12 to prevent leakage of the internal electrolyte. As a result, the inside of each single cell is sealed with the sealing material 16, and the electrolytic solution that may ooze out from the electrodes and the separator 15 is prevented from leaking out of the single cell, and the liquid junction between the single cells is prevented. .

  In the present embodiment, as shown in FIG. 3, a plurality of conductive lines 21 are provided on the end face 17 (see FIGS. 2 and 4) of each current collector 12 in a state where a plurality of bipolar electrodes 14 are laminated. The flexible wiring 20 is connected.

  In order to connect the conductive wire 21, the bipolar battery 1 of the present embodiment cuts one side on the side where the conductive wire 21 is connected in a state where a plurality of bipolar electrodes 14 are stacked via the separator 15. The cutting position is a position indicated by a chain line C shown in FIG. This cutting position is a position where all of the stacked current collectors 12 can be cut off at a position slightly inward from the edge of the side of the bipolar battery 1 while being stacked. By this cutting, the end faces 17 of the current collectors 12 can be aligned as shown in FIG.

  4A and 4B are diagrams showing the structure of the flexible wiring, in which FIG. 4A is a connection side partial plan view of a connection portion, and FIG. 4B is a cross-sectional view taken along line bb in FIG.

  The flexible wiring 20 is formed by embedding and integrating a plurality of conductive wires 21 in a resin 22 such as polyimide serving as a support member in a state of being insulated from each other by the resin 22. And since the front-end | tip part is connected with the end surface of the electrical power collector 12, a part of resin 22 is peeled and each conductive wire 21 is exposed.

  The arrangement pitch p of each conductive wire 21 is formed to be the same as the pitch P (see FIG. 5) of the current collector 12 in the stacked state. The arrangement pitch p of the conductive wires 21 and the pitch P of the current collectors 12 are both the center-to-center distances.

  For example, when 100 layers of bipolar electrodes 14 are laminated, the total thickness is about 5 to 10 mm, and the pitch P of each current collector 12 is about 0.05 to 0.1 mm. Therefore, the arrangement pitch p of the conductive wires 21 is also set to 0.05 to 0.1 mm in accordance with this.

  The end face of the current collector 12 and the conductive wire 21 are connected using an anisotropic conductive material.

  FIG. 5 is an enlarged cross-sectional view of the connecting portion for explaining the connection between the end face of the current collector and the conductive wire, and FIG. 6 is a schematic exploded perspective view of the connecting portion.

  In the present embodiment, an anisotropic conductive film 24 that is an anisotropic conductive material is used to connect the end face of the current collector 12 and the conductive wire 21.

  The anisotropic conductive film 24 is a polymer material having three functions of adhesion, conductivity, and insulation at the same time. This anisotropic conductive film 24 is basically a resin material in which conductive fine particles 25 are randomly blended, and is electrically conductive in the thickness direction (direction in which pressure is applied) in the crimped portion by thermocompression processing. It is a material having electrical anisotropy that exhibits insulation properties with respect to the surface direction of the crimping portion. Examples of such materials include anisotropic conductive films (manufactured by Hitachi Chemical Co., Ltd.), anisotropic conductive films (manufactured by Fujikura Corporation), and the like. A paste-like anisotropic conductive paste (manufactured by Fujikura Co., Ltd.) can also be used in the same manner.

  In the connection using the anisotropic conductive film 24, first, as shown in FIG. 5A, the anisotropic conductive film 24 is placed on the entire surface of the end face 17 of the current collector 12 of the stacked bipolar electrode 14. Then, the flexible wiring 20 is placed so that each conductive wire 21 coincides with the position of the current collector end face 17 from above. And as shown in FIG.5 (b), a pressing force is applied to the collector end surface 17 direction from the flexible wiring 20 side. As a result, the conductive fine particles 25 inside the anisotropic conductive film 24 aggregate in the direction in which the pressure is applied to electrically connect the current collector end face 17 and the conductive wire 21. In this state, the conductive fine particles 25 do not aggregate in the direction in which no pressure is applied, and thus do not conduct in the lateral direction. Accordingly, only the respective conductive wires 21 corresponding to the respective current collectors 12 are conducted, and the current collectors 12 and the conductive wires 21 are short-circuited with each other, or the non-corresponding current collectors 12 and the conductive wires 21 are short-circuited. There is nothing wrong.

  Here, the conductive fine particles 25 included in the anisotropic conductive film 24 are, for example, nickel particles, and the size thereof is 2 to 8 μm.

  On the other hand, the thickness of one current collector 12 can be formed in any way with a thickness of about 1 to 100 μm. Therefore, the thickness of the current collector 12 is not particularly limited, but in order to secure sufficient tsunami with the conductive wire 21, a plurality of conductive fine particles 25 are also formed in the width direction. It is desirable to be able to contact. From this viewpoint, the thickness of the current collector 12 is larger than 2 μm, which is the minimum diameter of the conductive fine particles 25, for example, preferably about 2 to 100 μm, and more preferably about 10 to 100 μm. Further, the interval between the adjacent current collectors 12 is formed so as to be larger than the maximum diameter of the conductive fine particles 25. Therefore, the interval PG (see FIG. 5) between the adjacent current collectors 12 is set to be larger than 8 μm. Preferably, it is 10 μm or more in consideration of manufacturing errors. The interval PG between the adjacent current collectors 12 is adjusted by the thicknesses of the positive electrode 11, the negative electrode 13, and the separator 15.

  On the other hand, the conductive wire 21 has a width pw (see FIG. 4) that can be in contact with at least one conductive fine particle 25 in the same manner as the thickness of the current collector 12, and an interval pg between adjacent conductive wires 21 (see FIG. 4). 4) is separated from the maximum diameter of the conductive fine particles 25. Therefore, the conductive line 21 has the same pitch p as the pitch P of the current collector 12, the width pw is larger than 2 μm (more preferably 10 μm or more), and the interval pg between adjacent conductive lines 21 is larger than 8 μm, preferably It forms so that it may become 10 micrometers or more. Further, the contact length (the length of the portion in contact with the current collector 12, that is, the length L where the copper wire is exposed in FIG. 4) is a length that can also contact at least one conductive fine particle 25. In other words, 10 μm is sufficient, but if it is too short, it may be difficult to manufacture, so about 1 mm is preferable, and more preferably about 5 mm to 10 mm.

  The connection position of the conductive wire 21 is preferably provided at a corner portion within about 30 mm from the end of the piola battery 1. As will be described later, when the piola battery 1 is packaged, a twist is applied to pull out the flexible wiring 20 to the outside. However, by providing a connection position of the conductive wire 21 at the corner portion, it is possible to perform simple bending. A 90 degree twist can be applied to one axis. Therefore, the occurrence of stress when changing the direction of the flexible wiring 20 can be reduced, and the connection reliability between the current collector 12 and the conductive wire 21 can be improved.

  The current collector 12 and the conductive wire 21 are connected by the anisotropic conductive film 24 only by applying a pressing force in the direction of the current collector end face 17, but in this embodiment, the current collector 12 and the conductive wire 21 are more reliably connected. As shown in FIG. 6, the clip member 26 serving as a holding member presses the flexible wiring 20 in the direction of the bipolar battery 1 and is attached so as to bite into the bipolar battery 1 so that the connection with the wire 21 is maintained. Thereby, the connection state of the electrical power collector 12 and the conductive wire 21 can be maintained stably and reliably.

  Further, the clip member 26 is formed on the flexible wiring 20 so that the flexible wiring 20 can be easily taken out from the package as shown in FIG. It also plays a role of stabilizing its shape while adding torsion. For this purpose, the clip member 26 is provided with a groove portion 27 that allows the shape of the flexible wiring 20 to be twisted 90 degrees with respect to the current collector end surface 17 by inserting the flexible wiring 20.

  By using such a clip member 26, for example, even when this bipolar battery is mounted on a vehicle that generates vibration such as an automobile described later, the current collector 12 and the conductive wire 21 are disconnected. Can be prevented.

  In addition, an auxiliary member or the like may be provided between the clip member 26 and the flexible wiring in order to further prevent displacement. The auxiliary member is preferably elastic synthetic rubber or resin material.

  The process for connecting the current collector 12 and the conductive wire 21 is somewhat flexible in the bipolar battery itself in a state where the bipolar electrode 1 is laminated. Therefore, a pressing force is applied from the flexible wiring 20 side toward the current collector end face 17. When added, the bipolar battery 1 itself may be deformed. Therefore, in the present embodiment, as shown in FIG. 8, the bipolar battery 1 in a state where a plurality of bipolar electrodes 14 are stacked is placed in the frame body 30, and the three sides excluding the upper and lower surfaces and the pressing side are suppressed. After preventing the battery 1 from being deformed, the flexible wiring 20 is attached so as to be pressed against the end face 17 of the current collector 12 by the clip member 26. In addition, the frame member 30 is provided with a cut 31 so that the clip member 26 just enters.

  By using such a frame member 30, the deformation of the bipolar battery 1 when the flexible wiring 20 is attached is prevented, and the conductive wire 21 and the current collector are fitted by inserting the clip member 26 into the notch 31 provided in the frame member 30. 12 can be used for alignment.

  In this way, the bipolar battery 1 to which the flexible wiring 20 is attached is sealed in a laminate pack under reduced pressure, so that pressure is applied to each current collector 12 almost uniformly by the laminate pack material. At this time, the positive electrode terminal plate 48 and the negative electrode terminal plate 49 (which may be further attached with electrode leads if necessary) provided on the current collectors 12a and 12b at the ends of the bipolar battery 1 are taken out from the laminate pack. At the same time, the flexible wiring 20 is also pulled out from the laminate pack. At this time, since the orientation of the flexible wiring 20 is twisted by 90 degrees, the flat surface of the flexible wiring 20 and the flatness of the laminate pack are parallel to each other, so that the bipolar battery 1 can be enclosed without an extra gap.

  FIG. 9 is a perspective view showing an embodiment when the direction of drawing out the flexible wiring is changed, and FIG. 10 is a perspective view showing the packaged battery in this case.

  In the embodiment shown in FIGS. 6 to 7 described above, an example in which the flexible wiring 20 is pulled out in the direction extending in the battery longitudinal direction is shown. However, the method of pulling out the flexible wiring 20 is not limited to this, for example, FIG. As shown in FIG. 10, the end face 17 connected to the conductive wire 31 may be in a direction perpendicular to the longitudinal side of the bipolar battery 1.

  In this case, as shown in FIG. 11, the shape of the clip member 28 is slightly different from the clip member 26 described above, and the groove 29 directs the flexible wiring 20 in the direction perpendicular to the longitudinal side of the bipolar battery 1. It is provided so that you can. Therefore, the flexible wiring 20 is attached to the longitudinal side of the bipolar battery 1 by being pressed by the clip member 28 using a frame material (not shown) in the same manner as described above. The flexible wiring 20 is attached to the groove 29 of the clip member 28 to change the direction.

  In the bipolar battery 1 configured as described above, since the conductive wire 21 is directly connected to the end face of the current collector 12, not only the current collector but also the positive and negative electrodes formed on the current collector, Also in this member, the same shape can be used for all bipolar electrodes to be laminated. Therefore, the manufacturing cost of each member can be reduced, and as a result, the cost of the battery itself can be reduced.

  In the present embodiment, the conductive wires 21 are connected to all the current collectors. Instead of this, for example, a plurality of current collectors such as every other current collector of stacked bipolar electrodes are used. One conductive wire may be connected every other body.

  The main members constituting the battery will be further described below.

[Current collector]
The current collector 12 is required to be formed by laminating a film having any shape by a thin film manufacturing technique such as spray coating, for example, aluminum, copper, titanium, nickel, stainless steel. (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. The current collector 12 may be a thin film of the above metal (or an alloy thereof).

[Positive electrode (positive electrode active material layer)]
The positive electrode includes a positive electrode active material. In addition, an electrolyte, a lithium salt, a conductive aid, and the like can be included in order to increase ion conductivity. In particular, it is desirable that at least one of the positive electrode and the negative electrode contains an electrolyte, preferably a polymer electrolyte. However, in order to further improve the battery characteristics of the bipolar battery, it is preferable to contain them in both.

As the positive electrode active material, a composite oxide of transition metal and lithium, which is also used in a solution-type lithium ion battery, can be used. Specifically, 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 · such LiFeO ₂ Examples thereof include Fe-based composite oxides. 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 positive electrode active material may have any particle size 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, the electrolyte is not a solid solution type. A particle size smaller than the particle size generally used in lithium ion batteries may be used. Specifically, the average particle diameter of the positive electrode active material is preferably 10 to 0.1 μm.

  As the electrolyte contained in the positive electrode, a solid polymer electrolyte, a polymer gel electrolyte, a laminate of these, and the like can be used. That is, the positive electrode can have a multi-layer structure, and on the collector side and the electrolyte side, a layer in which the type of electrolyte constituting the positive electrode, the type and particle size of the active material, and the mixing ratio thereof are changed is formed. You can also. Preferably, the ratio (mass ratio) between the polymer constituting the polymer gel electrolyte and the electrolytic solution is 20:80 to 2:98, and the ratio of the electrolytic solution is relatively large.

  The polymer gel electrolyte is a polymer skeleton having an ion conductivity in which an electrolytic solution usually used in a lithium ion battery is held, or a polymer skeleton having no lithium ion conductivity by itself. The thing etc. which hold | maintained the same electrolyte solution are contained.

  Here, the polymer used as the polymer gel electrolyte is, for example, a polymer having polyethylene oxide in the main chain or side chain (PEO), polyacrylonitrile (PAN), polymethacrylic acid ester, polyvinylidene fluoride (PVdF), polyfluoride. A copolymer of vinylidene chloride and hexafluoropropylene (PVdF-HFP) or the like is used. However, it is not limited to this.

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 the above, or a mixture thereof, cyclic carbonates such as propylene carbonate and ethylene carbonate; chain carbonates such as dimethyl carbonate, ethyl methyl carbonate, and diethyl carbonate; Tetrahydrofuran, 2-methyltetrahydrofuran, 1 Ethers such as 4-dioxane, 1,2-dimethoxyethane, 1,2-dibutoxyethane; Lactones such as γ-butyrolactone; Nitriles such as acetonitrile; Esters such as methyl propionate; Amides such as dimethylformamide Kinds: those using an aprotic organic solvent (plasticizer) in which at least one selected from methyl acetate and methyl formate or a mixture of two or more thereof can be used. However, it is not necessarily limited to these.

As the lithium salt, for _{example, LiPF 6, LiBF 4, LiClO} 4, LiAsF 6, LiTaF 6, LiAlCl 4, Li 2 B 10 Cl 10 and the like inorganic acid anion _{salts, Li (CF 3 SO 2)} 2 N, An organic acid anion salt such as Li (C ₂ F ₅ SO ₂ ) ₂ N or a mixture thereof can be used. However, it is not necessarily limited to these.

  Examples of the conductive aid include acetylene black, carbon black, and graphite. However, it is not necessarily limited to these.

  The blending amount of the positive electrode active material, electrolyte, lithium salt, and conductive additive in the positive electrode should be determined in consideration of the intended use of the battery (output importance, energy importance, etc.) and ion conductivity. For example, if the amount of the electrolyte in the positive electrode 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 is too large, the energy density of the battery is lowered. Therefore, in consideration of these factors, the electrolytic mass suitable for 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. A typical positive electrode active material layer has a thickness of about 10 to 500 μm.

[Negative electrode (negative electrode active material layer)]
The negative electrode 13 includes a negative electrode active material. In addition to this, an electrolyte, a lithium salt, a conductive material, or the like may be included in order to increase ion conductivity. Except for the type of the negative electrode active material, the contents are basically the same as those described in the section “Positive electrode”, and thus description thereof is omitted.

  As the negative electrode active material, a negative electrode active material that is also used in a solution-type lithium ion battery can be used. For example, 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. More preferred are titanium oxide, lithium-titanium composite oxide, and carbon. These may be used alone or in combination of two or more.

[Separator]
The separator 15 used here becomes an electrolyte layer, and keeps the active material itself in the positive electrode 11 and the negative electrode 13 without being mixed, and allows only ions to pass therethrough. As such a separator 15, for example, a gel electrolyte in which a polymer fiber, a polymer film, or the like is used as a base material, and an electrolytic solution is held in the base material by several mass% to about 98 mass% in the polymer skeleton is used. It is held and shaped into a film.

[Electrolytes]
The electrolyte included in the separator 15 is, for example, a polymer gel electrolyte. This electrolyte can also have a multilayer structure, and a layer in which the type of electrolyte and the component blending ratio are changed can be formed on the positive electrode side and the negative electrode side.

  When the polymer gel electrolyte is used, the ratio (mass ratio) between the polymer constituting the polymer gel electrolyte and the electrolytic solution is 20:80 to 2:98, which is a relatively large range of the electrolytic solution.

  As such a polymer gel electrolyte, a polymer skeleton having ion conductivity and an electrolyte solution usually used in a lithium ion battery are held, or a high-performance polymer that does not have lithium ion conductivity by itself. Those having a similar electrolyte solution held in the molecular skeleton are included. Since these are the same as the polymer gel electrolyte described as one type of electrolyte contained in the positive electrode, description thereof is omitted here.

  These polymer gel electrolytes can be included in the positive electrode and / or the negative electrode as described above in addition to the polymer electrolyte constituting the battery. However, different polymer electrolytes are used depending on the polymer electrolyte, positive electrode, and negative electrode constituting the battery. The same polymer electrolyte may be used, or different polymer electrolytes may be used depending on the layer.

  In addition, it is also possible to use a solid polymer electrolyte instead of the separator without including the electrolyte in the separator itself. The thickness of the electrolyte layer when a solid polymer electrolyte is used is not particularly limited. However, in order to obtain a compact bipolar battery, it is preferable to make it as thin as possible as long as the function as an electrolyte can be secured. The thickness of a general solid polymer electrolyte layer is about 10 to 100 μm. However, the shape of the electrolyte 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 surface by taking advantage of the manufacturing method.

[Positive electrode and negative electrode terminal]
The positive and negative terminal plates 48 and 49 function as electrode terminals for the entire battery. From the viewpoint of reducing the thickness of the battery, the terminal plates 48 and 49 are preferably as thin as possible. However, the electrodes (positive electrode and negative electrode), electrolyte, and current collector formed by film formation all have mechanical strength. Since it is weak, it is desirable to have strength to sandwich and support these from both sides. Furthermore, it can be said that the thickness of the positive electrode and the negative electrode terminal plate is usually preferably about 0.1 to 2 mm from the viewpoint of suppressing the internal resistance at the terminal portion.

  As the material of the positive electrode and the negative electrode terminal plate, materials usually used in lithium ion batteries can be used. For example, aluminum, copper, titanium, nickel, stainless steel (SUS), and alloys thereof can be used. Aluminum is preferably used from the viewpoints of corrosion resistance, ease of production, economy, and the like.

  The material of the positive electrode and the negative electrode terminal plate may be the same material or different materials. Furthermore, the positive electrode and the negative electrode terminal plate may be a laminate of different materials.

[Battery exterior material (battery case)]
In order to prevent external impact and environmental degradation, the bipolar battery is a battery that includes the entire battery stack including the template, which is the main body of the bipolar battery, in order to prevent external impact and environmental degradation during use. It may be housed in an exterior material or a battery case.

  From the viewpoint of weight reduction, a conventionally known battery exterior material such as a polymer-metal composite laminate film in which a metal (including an alloy) such as aluminum, stainless steel, nickel, or copper is covered with an insulator such as a polypropylene film is used. The battery laminate (bipolar battery 1) is preferably sealed under reduced pressure by joining a part or all of the peripheral part thereof by thermocompression bonding.

  In the present embodiment, a laminate pack is used (see FIGS. 7 and 10). However, it goes without saying that a battery can be similarly formed even if enclosed in a metal case or the like.

[Battery]
The laminated packed battery 40 can be provided as an assembled battery or a battery module by connecting a plurality of the batteries 40 in series and / or in parallel. Even when such an assembled battery or an assembled battery module is produced, the shape of each of the parts constituting the bipolar battery 1 is the same, and the manufacturing cost can be reduced. The assembled battery and the assembled battery module which are the bodies can also greatly reduce the manufacturing cost.

  FIG. 12 is a perspective view of the assembled battery, and FIG. 13 is a view of the internal configuration of the assembled battery as viewed from above.

  As shown in the figure, this assembled battery 50 is obtained by further connecting in parallel a plurality of the above-described batteries 40 connected in series. Between the batteries 40, terminal plates 48 and 49 of the batteries are connected by a conductive bar 53. The assembled battery 50 is provided with electrode terminals 51 and 52 on one side of the assembled battery 50 as electrodes of the assembled battery 50.

  In this assembled battery, ultrasonic welding, thermal welding, laser welding, rivets, caulking, electron beam, or the like can be used as a connection method when the batteries 40 are directly connected and connected in parallel. By adopting such a connection method, a long-term reliable assembled battery can be manufactured.

  In addition, the connection of the battery 40 as an assembled battery may connect all the batteries 40 in parallel, and may connect all the batteries 40 in series.

  FIG. 14 is a perspective view of the assembled battery module.

  The assembled battery module 60 is a module in which a plurality of the assembled batteries 50 described above are stacked and the electrode terminals 51 and 52 of each assembled battery 50 are connected by power tabs 61 and 62.

  By modularizing the assembled battery 50, for example, an assembled battery module optimum for in-vehicle use such as an electric vehicle or a hybrid vehicle is obtained. Such an assembled battery module is also a kind of assembled battery.

[Car]
FIG. 15 is a schematic diagram of the automobile 100 on which the assembled battery module 60 is mounted, and FIG. 16 is a block diagram showing an example of an electrical system in the automobile including the assembled battery module 60.

  This automobile is an automobile mounted with the above-described assembled battery module 60 and used 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 to improve the travel distance per charge of the battery, and improve the life of the vehicle-mounted battery.

  The block diagram of the electric system shown in FIG. 16 is that of a hybrid vehicle, and mainly shows a power supply system, but also partially shows a power transmission path and the like.

  This hybrid vehicle is equipped with an assembled battery module 60 composed of a plurality of bipolar batteries 1 according to the present invention, and the flexible wiring 20 drawn from each bipolar battery 1 is drawn into the battery control unit 110 via the voltmeter 115. Yes. Here, the voltmeter 115 has a switch mechanism (not shown) for measuring the voltage of an arbitrary unit cell in response to a command from the battery control unit 110 and responding to the measured value to the battery control unit 110. . In normal control, the battery control unit 110 switches the combination of the conductive wires 31 for each bipolar battery 1 and sequentially scans the cells inside the battery to measure the voltage.

  On the other hand, the power tabs 61 and 62 of the assembled battery module 60 are connected to the inverter 111.

  Further, in order to measure the voltage and current of each bipolar battery 1 constituting the assembled battery module 60, a wiring 120 is drawn to the battery control unit 110 for each bipolar battery 1. Further, an ammeter 130 is provided on the wiring on the power tab 61 side in order to monitor the current flow of the assembled battery module 60 as a whole, and the measured value enters the battery control unit 110. Further, a temperature sensor 131 is provided in the vicinity of each bipolar battery 1, and the temperature of each bipolar battery 1 is monitored by the battery control unit 110.

  The power wiring from the inverter 111 is connected to the motor 150. In addition, signal wiring for controlling the inverter 111 and the motor 150 is connected to the motor controller 151.

  The power of the motor 150 is transmitted to the wheels 153 via the transmission 152. Further, power from the engine 154 is also transmitted to the transmission 152. In addition, the brake 155 hits the wheel 153. An engine controller 156 is connected to the engine 154, and a brake controller 157 is connected to the brake 155. A transmission controller 158 is connected to the transmission 158.

  The battery control unit 110, the motor controller 151, the engine controller 156, the brake controller 157, and the transmission controller 158 are connected to the vehicle controller 160 via a network 170 such as an in-vehicle LAN. It is connected to a human interface 161 such as various in-vehicle alarms and indicator lamps.

  In the electrical system configured as described above, the battery control unit 110 mainly performs charge / discharge control of the assembled battery module 60. For example, by measuring the voltage in units of single cells as described above, The amount of charge in the battery can be controlled in a very fine unit of each single cell. The conductive wire 21 can be used for this control. For example, judging from the measured voltage value of a unit cell that is overdischarged or overcharged (or is likely to be in such a state), both ends of the unit cell are bypassed to bypass such a unit cell. Thus, it is possible to perform control such as short-circuiting between the conductive wires 21 from the current collector 12 by switching.

  Of course, such a control form is arbitrary, and according to the present invention, various controls can be performed in a fine control unit of a single cell unit.

  The present invention can be applied to a lithium ion secondary battery.

It is a figure for demonstrating the bipolar electrode used by this invention. 1 is a view for explaining an embodiment of a bipolar battery according to the present invention. It is a schematic perspective view of the bipolar battery. It is drawing which shows the structure of flexible wiring. It is an expanded sectional view of the connection part for demonstrating the connection of the end surface of an electrical power collector, and a conductive wire. It is a general | schematic disassembled perspective view of the connection part of the end surface of an electrical power collector, and a conductive wire. It is a perspective view which shows the external appearance of the packaged battery. It is drawing for demonstrating the connection process of a collector and a conductive wire. It is an expanded sectional view of the connection part for demonstrating the other connection form of the end surface of an electrical power collector, and a conductive wire. It is a perspective view which shows the external appearance of the packaged battery in the other connection form of the end surface of an electrical power collector, and a conductive wire. It is a general | schematic disassembled perspective view of the connection part in the other connection form of the end surface of an electrical power collector, and a conductive wire. It is a perspective view of an assembled battery. It is drawing which looked at the internal structure of the said assembled battery from upper direction. It is a perspective view of an assembled battery module. It is the schematic of the motor vehicle carrying the said assembled battery module. It is a block diagram which shows the electric system of a hybrid vehicle.

Explanation of symbols

1 ... Bipolar battery,
11 ... positive electrode active material layer,
12 ... current collector,
13 ... negative electrode active material layer,
15 ... separator,
16 ... sealing material,
17 ... end face,
20 ... Flexible wiring,
21 ... conductive wire,
24. Anisotropic conductive film,
25. Conductive fine particles,
26, 28 ... Clip members,
40 ... Battery,
50 ... assembled battery,
60 ... assembled battery module,
100 ... car,
110 ... Battery control unit,
115: Voltmeter.

Claims (10)

A bipolar electrode in which a positive electrode is formed on a first surface of a current collector and a negative electrode is formed on a second surface opposite to the first surface;
A bipolar battery in which an electrolyte layer is interposed between the positive electrode and the negative electrode and a plurality of the bipolar electrodes having the same shape are stacked,
A conductive wire electrically connected to an end face of the current collector;
A support member for supporting the conductive wire in a position that matches the position of the end face of the current collector and insulating it from the other conductive wires;
A bipolar battery characterized by comprising:   A plurality of the conductive wires are arranged in a state of being insulated from each other on the one support member, and the arrangement pitch of the plurality of conductive wires is the end surface of the current collector in a state where the plurality of conductive wires are stacked. The bipolar battery according to claim 1, wherein the bipolar battery is equal to the pitch.   The bipolar battery according to claim 2, wherein the conductive wire is held in the end face direction by a holding member from the outside of the support member.   The bipolar battery according to claim 1, wherein the conductive wire is electrically connected to the end face by an anisotropic conductive material.   The anisotropic conductive material includes conductive fine particles, and the thickness of the current collector is larger than the minimum diameter of the conductive fine particles, and the interval between the adjacent current collectors is larger than the maximum diameter of the conductive fine particles. 5. The bipolar battery according to claim 4, wherein the conductive wires are separated from each other by a distance larger than a maximum diameter of the conductive fine particles.   The bipolar battery according to any one of claims 1 to 5, wherein the conductive wire is drawn out of a package covering the bipolar battery.   The conductive wire is connected to the end surface at a position within 30 mm from a side adjacent to the side having the end surface, extended from the side having the end surface in the direction of the adjacent side, and drawn from the package. The bipolar battery according to claim 6. Forming a bipolar electrode in which a positive electrode is formed on a first surface of a current collector and a negative electrode is formed on a second surface opposite to the first surface;
Laminating a plurality of the bipolar electrodes having the same shape with an electrolyte layer interposed between the positive electrode and the negative electrode;
Aligning the end faces of the current collector of the stacked bipolar battery; and
Electrically connecting conductive lines supported by a support member so as to coincide with the position of the end face of the current collector through an anisotropic conductive material to the aligned end faces; and
A method for producing a bipolar battery, comprising: Aligning the end faces of the current collector comprises:
9. The method of manufacturing a bipolar battery according to claim 8, wherein the method is performed by cutting a side on which the end faces of the stacked bipolar batteries are aligned. Battery pack, characterized in that connecting the battery as claimed plurality in series and / or parallel to one of the claims 1-7.

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