JP5151115B2 - Bipolar secondary battery - Google Patents

Description

  The present invention relates to a bipolar secondary battery, and more particularly to a bipolar secondary battery having a structure that enables measurement of voltage and temperature of a single battery layer.

  In recent years, in order to cope with air pollution and global warming, reduction of the amount of carbon dioxide has been strongly desired. In the automobile industry, there is a great expectation for reducing carbon dioxide emissions by introducing electric vehicles (EV) and hybrid electric vehicles (HEV), and the development of secondary batteries for motor drive that holds the key to commercialization of these is thriving. Has been done.

  As a secondary battery for driving a motor, a lithium ion secondary battery having the highest theoretical energy among all the batteries is attracting attention, and is currently being developed rapidly. When using a lithium ion secondary battery, usually, a plurality of battery modules are connected in series to form a battery module, and further, a battery pack is formed by connecting the battery modules in series to obtain a high energy density. Yes. However, in such an assembled battery, the resistance due to the connection between the batteries and the connection between the battery modules is added, the internal resistance of the entire assembled battery at the time of charging / discharging is increased, and a high output density cannot be obtained.

  Therefore, a plurality of bipolar electrodes in which a positive electrode layer is formed on one surface of a current collector and a negative electrode layer is formed on the other surface are arranged in series with an electrolyte layer interposed therebetween, whereby a positive electrode layer, Bipolar lithium ion secondary batteries (also referred to simply as “bipolar secondary batteries” in the present specification) having battery elements in the form of laminated single battery layers having a laminated structure of an electrolyte layer and a negative electrode layer have attracted attention. Yes. In this bipolar secondary battery, a plurality of single battery layers are connected in series to constitute a battery element.

  In the bipolar secondary battery having such a configuration, even when the same single battery layer is stacked, the voltage of each single battery layer is not necessarily constant and may vary. When the voltage of each cell layer varies, there is a risk that the cell layer having a large voltage will deteriorate during use and may be damaged.

  Moreover, in the bipolar secondary battery, after the single battery layers are once laminated and the battery elements are formed, the total voltage of all the single battery layers can be measured, but for each single battery layer, the positive electrode layer and the negative electrode layer It is difficult to measure the voltage.

In order to solve this problem, in Patent Document 1, a voltage measurement lead wire composed of a flexible flat cable for measuring a voltage for each cell layer is attached to a current collector sandwiching the cell layers by ultrasonic welding. It proposes a configuration to connect by. By attaching the voltage measurement lead wires in this way, the voltage and capacity of each single cell layer can be checked even after the battery elements are formed once, and there are defective battery units. Can be removed during battery manufacture.
JP 2005-235463 A

  However, in the bipolar secondary battery described in Patent Document 1, current collectors adjacent to each other in the battery are in contact with each other, or a short circuit occurs due to a slight unevenness at the end of the cell layer in the battery element. In order to prevent such an inconvenience, an insulating sealing material is provided around each single cell layer (cell). This insulating sealing material is disposed so as to cover the end face of the current collector. For this reason, it is difficult to attach a voltage measurement lead wire or a temperature sensor to the current collector of the single cell layer after the insulating sealing material is formed or after the single cell layer is laminated.

  The present invention has been made in view of the above circumstances, and after an insulating sealing material is formed or after a single battery layer is laminated, a lead wire or a temperature sensor is provided on the current collector of the single battery layer. An object of the present invention is to provide a structure of a bipolar secondary battery to which can be attached.

In order to solve the above problems, a bipolar secondary battery according to the present invention includes a bipolar electrode having a positive electrode layer formed on one surface of a current collector and a negative electrode layer formed on the other surface, and an electrolyte layer. A plurality of batteries are arranged in series, thereby constituting a battery element in which a single battery layer having a laminated structure of the positive electrode layer, the electrolyte layer, and the negative electrode layer is laminated, and is formed on the outer periphery of the single battery layer. In the bipolar secondary battery provided with a sealing material that insulates between the current collectors, the electrolyte layer is made of an electrolyte held in a separator disposed between the positive electrode layer and the negative electrode layer, and the separator is greater than the current collector, wherein the extending portion that extends outwardly disposed than the positive electrode layer and the negative electrode layer on the current collector at least one side of the periphery of the battery element, the extending portion of the current collector The seal material is provided on the seal and the seal Further, a non-sealing portion where the sealing material does not exist is formed on an extension portion of the current collector in an outer peripheral portion of the current collector, and a detection element for voltage measurement or temperature detection is arranged and brought into contact with the non-sealing portion. It is characterized by that.
In order to solve the above problems, a bipolar secondary battery according to the present invention includes a bipolar electrode in which a positive electrode layer is formed on one surface of a current collector and a negative electrode layer is formed on the other surface. A plurality of cells are arranged in series with the layer interposed therebetween, thereby constituting a battery element in which a single battery layer having a stacked structure of the positive electrode layer, the electrolyte layer, and the negative electrode layer is formed, and an outer periphery of the single battery layer In a bipolar secondary battery in which a sealing material for insulating between the current collectors is provided in a part, the current collector on at least one side of the peripheral part of the battery element extends outward from the positive electrode layer and the negative electrode layer. An extending portion is provided, the sealing material is provided on the extending portion of the current collector, and the sealing material is not present on the extending portion of the current collector in a further outer peripheral portion of the sealing material. A non-seal part is formed, and a temperature detection test is performed on the non-seal part. An element is disposed and brought into contact, and a leading end portion of a lead wire is disposed as the detection element. A sensing portion in which a temperature sensor is covered with an insulator is provided at the leading end portion of the lead wire. A sensing unit comprising a thermal fuse and having a thermal fuse covered with an insulator is provided in a current collector of two or more single cell layers, and the thermal fuses are connected in series to form a temperature relay. It is characterized by that.
Furthermore, in order to solve the above problems, a bipolar secondary battery according to the present invention includes a bipolar electrode in which a positive electrode layer is formed on one surface of a current collector and a negative electrode layer is formed on the other surface. A plurality of cells are arranged in series with the layer interposed therebetween, thereby constituting a battery element in which a single battery layer having a stacked structure of the positive electrode layer, the electrolyte layer, and the negative electrode layer is formed, and an outer periphery of the single battery layer In the bipolar secondary battery in which a sealing material for insulating between the current collectors is provided in a part, the electrolyte layer is composed of an electrolyte held in a separator disposed between the positive electrode layer and the negative electrode layer, and the separator Is larger than the current collector, the current collector on at least one side of the peripheral portion of the battery element is provided with an extending portion extending outward from the positive electrode layer and the negative electrode layer, and the current collector is extended. The sealing material is provided on the existing part, and the front On the current collector of the extending portion in yet outer periphery of the sealing material, characterized by having a non-sealing portion in the absence of the sealing material.

  Since a non-conductive material is used for the sealing material, it is difficult to arrange a lead wire at a position where the sealing material exists to achieve a good electrical or thermal connection. However, in the present invention, a non-seal part where no sealant is present is formed on the outer periphery of the sealant on the current collector, and the exposed part of the current collector is present. A detection element such as a voltage measurement lead wire or a temperature sensor can be easily attached to or in thermal contact with each other.

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

<First Embodiment: FIGS. 1 to 4>
FIG. 1 is a schematic cross-sectional view showing a part of the structure of a bipolar secondary battery according to the first embodiment of the present invention, and FIG. 2 is a perspective view showing the structure of the bipolar secondary battery according to the first embodiment. FIG. 3 and FIG. 3 are top views thereof.

  As shown in FIG. 1, a bipolar secondary battery 1 of the present invention has a positive electrode active material layer (positive electrode layer) 3 formed on one surface of a current collector 2 made of a rectangular SUS foil, and the other surface. A bipolar electrode 5 on which a negative electrode active material layer (negative electrode layer) 4 is formed is laminated with an electrolyte layer formed by holding an electrolyte in a separator 6 and a plurality of sheets are arranged in series. A single battery layer 7 is formed by a laminated structure in which an electrolyte layer is sandwiched between the positive electrode layer 3 and the negative electrode layer 4, and a plurality of single battery layers 7 are further laminated to form a battery element 8. The cell layer 7 is formed in a rectangular shape and the battery element 8 is formed in a cubic shape. However, in the present invention, these shapes are not essential, and may be other polygonal shapes, circular shapes, or the like. Good.

  On one side of the peripheral part of the battery element 8, the current collector 2 extends outward from the single battery layer 7, and on the extended part L of the current collector 2, Further, an insulating sealing material 9 that insulates between the current collectors 2 is disposed. The sealing material 9 is used to prevent inconveniences such as a short circuit caused by inconveniences between adjacent current collectors in the battery and slight unevenness of the end portions of the unit cell layers in the battery element 8. As shown in FIGS. 2 and 3, an insulating adhesive is applied to the rectangular surface of the current collector 2 in the shape of a rectangular frame with a predetermined width W1 along the outer peripheral portion thereof. Provided. Specifically, it is formed by applying a one-component uncured epoxy resin as a seal precursor to the surface of the current collector 2 using a dispenser as shown in FIGS.

  The sealing material 9 is provided on both surfaces of the current collector 2 for each single cell layer so as to insulate the current collectors 2 adjacent to each other in the region of the extending portion L. Yes. That is, the first sealing material 9a is provided on one surface side where the detection element of the current collector 2 is to be provided, and the second sealing material is provided on the other surface side of the current collector 2 where no detection element is provided. 9b is provided. In this embodiment, the first sealing material 9a and the second sealing material 9b have the same configuration, and both are formed in the form of an insulating layer having a predetermined width W1 that insulates between the current collector 2 and the separator 6. .

  On one side of the rectangular peripheral portion of the battery element 8, the seal material 9 does not exist on the extending portion L of the current collector 2 in the outer peripheral portion of the seal material 9 as indicated by the length L 1. That is, the non-seal part 10 (current collector exposed part 2a) where SUS of the current collector 2 is exposed is formed, and a space part 10a is formed between the separator 6 and the upper part. The detection element 11 for voltage measurement or temperature detection is provided on the non-sealing portion 10 on the one side of the positive electrode layer 3 or the negative electrode layer 4 in this non-sealing portion 10, that is, on the side where the positive electrode layer 3 exists in this embodiment. It arrange | positions and becomes a structure electrically connected with the collector exposed part 2a.

  In this embodiment, the detection element 11 is a tip portion of a voltage measurement lead wire 12 (hereinafter also simply referred to as a lead wire 12) for voltage adjustment, voltage detection, and the like. The lead wire 12 has a width of 5 mm, It consists of a 1 to 20 μm thick metal foil, here a copper foil. And the lead wire 12 which consists of this copper foil is electrically connected to the collector exposed part 2a which is the extension part L of the collector 2 using a conductive adhesive. Adhesion of the lead wire 12 using this conductive adhesive is performed simultaneously with the step of applying the epoxy resin of the sealing material 9, and the operation is sequentially repeated as the unit cell layers 7 are laminated, It is preferable to implement.

  As the conductive adhesive, a conductive adhesive filled with a metal such as silver, copper, gold, aluminum, nickel, platinum, solder, or an epoxy resin adhesive filled with alumina can be used. Then, a conductive adhesive filled with silver is used.

  As shown in FIG. 2, among the lead wires 12, the lead wires 12 corresponding to the outermost unit cell layer 7 in the stacking direction are arranged close to the outside in the plane direction. With respect to the lead wires 12 for the remaining unit cell layers 7, the attachment positions of the lead wires 12 are sequentially shifted so that the lower one in the stacking direction is inward along the length direction of the side of the battery element 8. Thus, they are arranged so as not to overlap each other in the stacked state. Further, as shown in FIG. 3, all the lead wires 12 are not arranged uniformly over the entire width of one side of the battery element 8, but are arranged as close as possible to one corner of the battery element 8.

  In the present embodiment, the tip end portion of the lead wire 12 is attached to the non-seal portion 10 remaining without being applied with the sealing material 9 on the extending portion L of the current collector 2 via a conductive adhesive, Electrically connected. For this reason, it is easier to attach the lead wire 12 than in the case where the lead wire 12 is connected to the current collector surface by conventional ultrasonic welding and the end surface of the current collector 2 is covered with the sealing material 9. As indicated by the arrows, it is possible to attach the lead wires 12 to the current collector 2 of each unit cell layer after the unit cell layers are stacked. The lead wire 12 is connected to a control circuit (not shown) and used for checking the voltage of each single cell layer, so that the state of the battery can be managed. If a failure occurs in the cell layer 7, it can be detected and removed.

  In the present embodiment, the separator 6 has a larger area than the current collector 2, and extends by a length D outside the current collector 2. With this structure, it is easy to ensure insulation between the current collectors 2 at the outer peripheral portion of the sealing material 9 at the attachment portion of the lead wire 12. That is, the insulation between the bipolar electrodes 5 can be secured in the extending portion L of the current collector 2, and the lead wire is extended in the range of the extending portion D of the separator 6 that extends outward. Mutual insulation can be ensured.

  The battery element 8 is connected to electrode tabs 13 and 14 shown in FIG. The electrode tab 13 (positive electrode tab) is connected to the current collector 2 on the positive electrode layer 3 side of the battery element 8, and the electrode tab 14 (negative electrode tab) is connected to the current collector 2 on the negative electrode layer 4 side. The battery element 8 is hermetically sealed with the exterior film 15 to constitute the bipolar secondary battery 1. At this time, the lead wires 12 are converged and taken out as a monitor tab 16 to the outside of the battery.

<Second Embodiment: FIGS. 5 to 7>
5 to 7 show a second embodiment of the present invention.

  The bipolar secondary battery 1 according to this embodiment also has the same stacked structure of the single battery layer 7 and the battery element 8 as in the case of FIGS. That is, as shown in FIG. 5, a bipolar electrode 5 in which a positive electrode layer 3 is formed on one surface of a current collector 2 made of SUS foil and a negative electrode layer 4 is formed on the other surface is connected to a separator 6 as an electrolyte. Are stacked with an electrolyte layer sandwiched therebetween, and a plurality of them are arranged in series. A single battery layer 7 is formed by a structure in which an electrolyte layer is sandwiched between the positive electrode layer 3 and the negative electrode layer 4, and a plurality of single battery layers 7 are laminated to form a battery element 8. In addition, the current collector 2 has an extending portion L that extends outward from the unit cell layer 7. In the extending portion L of the current collector 2, around the unit cell layer 7, A sealing material 9 that insulates between the current collectors 2 is disposed.

  However, the separator 6 is only slightly protruded from the positive electrode layer 3 and the negative electrode layer 4 into the extending portion L of the current collector 2. Further, as shown in FIGS. 6 and 7, the sealing material 9 has an insulating adhesive made of epoxy resin in a frame shape with a predetermined width W2 along the outer periphery of the rectangular surface of the current collector 2. It is provided by applying. In the case of the embodiment of FIG. 5, the sealing material 9 is provided for each single cell layer so as to insulate the current collectors 2 adjacent to each other within the region of the extending portion L. . Then, on one side of the peripheral portion of the battery element 8, on the extending portion L of the current collector 2, the presence of the sealing material 9 as shown by the length L1 further on the outer peripheral portion of the sealing material 9 The non-seal part 10 which is not to be performed, that is, the collector exposed part 2a is formed.

  In this embodiment, the separator 6 is slightly extended from the positive electrode layer 3 and the negative electrode layer 4 so that the presence of the separator 6 does not get in the way of the portion where the detection element 11 is to be arranged. It is terminated at a portion protruding into the portion L. As a means for this, the separator 6 may be shifted in the left direction in FIG. 5, or the separator 6 itself may be made small. In any case, outside the end of the separator 6, a sealing material 9 is disposed in the form of an insulating layer having a width W2 between adjacent current collectors 2, and a current collector having a length L1 is disposed outside the sealant 9. The non-seal part 10 which is the exposed part 2a is formed.

  In this embodiment, the non-sealed portion 10 having the length L1 is provided with a resistor 17 whose resistance value varies depending on the temperature as the detection element 11 for voltage measurement or temperature detection. The resistor 17 whose resistance value changes with temperature is an element such as a thermistor, a platinum resistance temperature detector, a positive thermal conductor, or a thermal fuse whose resistance value increases dramatically when the temperature rises above a specified level. One resistor 17 is provided for each cell layer with a lead wire. The resistor 17 is attached after the unit cell layers 7 are laminated, but may be sequentially applied at the stage where the unit cell layers 7 are laminated.

  As an arrangement form of these resistors 17, as shown in FIG. 6, the resistors 17 belonging to the outermost unit cell layer 7 in the stacking direction are arranged close to the outermost side in the plane direction. Regarding the resistors 17 belonging to the remaining unit cell layers 7, the attachment positions of the resistors 17 are sequentially shifted so that the lower ones in the stacking direction are inward along the sides of the battery elements 8, and are stacked. Are arranged so as not to overlap each other. In addition, the resistors 17 are not arranged uniformly over one side of the battery element 8, but are arranged close to one corner area on one side of the rectangular surface of the battery element 8 as shown in FIG. doing.

  The resistor 17 is provided with a size of, for example, 1 cm × 1 cm × 60 μm in the space 10 a on the non-sealed portion 10. Since the resistor 17 is attached to the current collector exposed portion 2a in the non-seal portion 10 capable of electrical contact, the single cell layer current collector is compared with the conventional configuration in which the sealing material 9 covers the end surface of the current collector 2. It can be easily attached to the electric body 2. Therefore, it is possible to attach the resistor 17 in the individual steps of laminating the unit cell layer 7 or after the battery element 8 is formed.

  Of the surface area of the non-seal part 10 of the current collector 2, the surface area other than the area where the resistor 17 is disposed, that is, the SUS exposed part, is the same as the seal material 9 in order to eliminate the risk of short circuit. An insulating material such as an epoxy resin is preferably provided. In this case, it is only necessary to cover the current collector exposed portion 2a on the surface side of the positive electrode layer 3, and it is not necessary to seal between the current collector SUS foil on the surface side of the negative electrode layer 4 to be laminated later. .

<Third Embodiment: FIGS. 8 to 10>
8 to 10 show a third embodiment of the present invention. The laminated structure of the single cell layer 7 which is a premise is the same as in the case of FIGS. 1 to 4, and the current collector 2 extends outside the single cell layer 7 on one side of the peripheral portion of the battery element 8. The separator 6 has an extension L, and the separator 6 extends outside the current collector 2 by a length D.

  However, the structure of the seal portion is different from that in FIGS. 1 to 4 as follows. The sealing material 9 provided around the unit cell layer 7 has a predetermined width close to the substantially entire region in the extending direction width (L) of the extending portion L between the extending portion L of the current collector 2 and the separator 6. It is provided as an insulating layer having a width W3. The sealing material 9 is provided on both surfaces of the current collector 2, but the surface side of the current collector 2 where the detection element 11 is disposed, and the surface side of the current collector 2 where the detection element 11 is not disposed. The structure is different. In the case of this embodiment, the surface side of the current collector 2 on which the detection element 11 is disposed is the surface side of the current collector 2 on which the positive electrode layer 3 is formed, and the detection element 11 is not disposed. The surface side of the current collector 2 is the surface side of the current collector 2 on which the negative electrode layer 4 is formed.

  On the surface side where the detection element 11 is disposed, that is, on one surface side of the current collector 2 on which the positive electrode layer 3 is formed, the extending portion L extends as viewed from the surface of the current collector 2. Although the first sealing material 9a is adhered to the surface of the current collector 2 up to the middle of the full width in the direction (L), the first sealing material 9a is present outside the region, The first sealing material 9a is not bonded to the surface of the current collector 2, and in that sense, the non-bonding portion 18 is formed. The non-bonding portion 18 is a hollow portion formed in the lower portion of the sealing material 9 as a concave portion in which the leading end portion of the lead wire 12 is disposed or enters. Also in this form, when viewed on the surface of the extending part L of the current collector 2, a form in which a non-seal part 10 having no seal material is provided in the form of a non-adhesive part 18 on the outer periphery of the seal material 9. It can be understood that.

  On the other hand, on the surface side where the detection element 11 is not disposed, that is, on the other surface side of the current collector 2 on which the negative electrode layer 4 is formed, the second sealing material 9b is bonded to the surface of the current collector 2 and has a width. An adhesive portion 19 of W3 is formed.

  In the case of the embodiment of FIG. 8, the tip end portion of the lead wire 12 is arranged or inserted into the non-adhered portion 18 on the current collector 2, that is, the cavity portion where the exposed portion of the current collector 2 is present, and the state When the pressure is applied to the stacked body in the stacking direction, the leading end portion of the lead wire 12 is bonded to the current collector 2. Alternatively, the tip of the lead wire 12 is first disposed on the exposed surface of the current collector 2 via a conductive adhesive at the same time as or before the application of the sealing material 9, and then the sealing material. By applying and curing 9, the leading end of the lead wire 12 is attached to the current collector 2 and is electrically connected. In this way, one lead wire 12 is provided for each cell layer.

  As described above, in the region of the width W3 where the seal material 9 exists, the non-adhesive portion 18 (non-seal) to which the seal material 9 is not attached as the lead wire attachment is further outside the adhesive portion 19 to which the seal material 9 is adhered. By forming the portion 10) and leaving the exposed portion of the current collector 2, the lead 2 for voltage measurement can be provided on the current collector 2 in good electrical contact.

  In this case, particularly preferably, the lead wire 12 is first attached to the current collector 2 on the positive electrode layer 3 side, and then the first sealing material 9a is applied so as to cover the tip of the lead wire 12, A sealing material layer having a structure may be formed. In addition, the second sealing material 9b formed after the separator 6 is laminated is also preferably arranged so as to lie over the lead wire 12 when viewed from the lamination direction.

  According to the embodiment of FIGS. 8 to 10 described above, (a) not only the lead wire 12 is bonded with the conductive adhesive on the bonding surface, but also the leading end of the lead wire 12 is the first seal on the upper side. Since it is held by the material 9a, the holding strength of the lead wire 12 is improved. (B) Regarding the sealing structure by the second sealing material 9b on the separator 6, since the area of the second sealing material 9b can be widened, the sealing performance is improved. (C) If the lead wire 12 is a flexible wiring, which will be described later, the adhesive force between the resins of, for example, polypropylene (PP), which is a resin of the flexible substrate constituting the lead wire 12, and the epoxy resin of the first sealing material 9a, Since one sealing material 9a layer is strongly bonded, a higher sealing effect can be expected. The advantages are obtained.

<Fourth Embodiment: FIGS. 11 and 12>
As a further preferred embodiment of the first to third embodiments, a configuration example in which the flexible wiring 20 is used for the lead wire 12 is shown in FIGS.

  The flexible wiring 20 has a cross-sectional structure in which a conductive pattern 22 made of metal is formed on one surface of an insulating flexible substrate 21 and this conductive pattern 22 is covered with an insulating cover material 23 as shown in FIG. Further, the flexible wiring 20 has a planar shape, as shown in FIG. 11, a connection lead portion 24 in which wiring leads are juxtaposed in parallel, and the direction of the wiring lead is changed at a right angle and the wiring leads are converged. And an extending portion 25.

  Since the flexible wiring 20 having this structure is thin and can be configured as, for example, a flexible flat cable, it is particularly suitable when an element such as a temperature sensor is disposed as the detection element 11. Therefore, FIG. 11 shows an example in which the temperature sensor 26 is provided in each connection lead part 24 (only one of the connection lead parts 24 is representatively shown in FIG. 11), and each sensing part is configured. This sensing part has a structure in which the temperature sensor 26 and the wiring lead (conductive pattern) are covered with a thin film insulating material, that is, the thin connection lead part 24 on the SUS foil (current collector exposed part 2a) of the current collector 2. Therefore, the temperature difference between the SUS foil of the current collector 2 and the temperature sensor 26 is small, so that the temperature of the single cell layer 7 can be measured with high response. Here, the temperature sensor 26 is provided for each single cell layer, and constitutes a temperature measurement unit of a temperature measurement system having a one-to-one correspondence output with respect to a plurality of temperature detection points. It is also possible to adopt a form in which a single battery layer 7 is provided, or a temperature sensor 26 typically detects the temperature of a plurality of single battery layers 7.

  Furthermore, the flexible wiring 20 having the above-described structure is also suitable when the wiring is drawn out from the laminate outer film 15. Therefore, in the vicinity of the terminal end of the extension portion 25, as shown in FIG. 11, when the extension portion 25 of the flexible wiring 20 is pulled out from the exterior film 15, the inside and outside are sealed. A vacuum seal portion 27 is provided, and the extending portion 25 is drawn out from the vacuum seal portion 27 in the form of a monitor tab 16 to the outside of the battery. That is, the laminated bipolar electrode 5 is laminated and covered with the outer film 15, and the flexible wiring 20 is wired between the heat-sealing seal structures of the outer film 15.

  The flexible wiring 20 has a structure in which a metal conductive pattern 22 is covered with a synthetic resin and firmly bonded in advance, and the outer skin of the flexible wiring 20 is bonded to the resin of the exterior film 15. Greater adhesive strength is ensured than the structure in which the metal lead wire 12 and the plastic are thermally fused separately.

  Next, a specific configuration of the flexible wiring 20 will be described.

  The flexible substrate 21 is made of a thin film of engineering plastic such as polyimide (PI) or polyethylene terephthalate (PET). The film thickness is about 1 to 100 μm, and the thickness of the connection lead portion 24 that is the tip of the comb teeth is preferably about half the thickness of the electrode layer of the single cell layer to which the connection lead portion 24 is connected.

  The metal that is provided on the flexible substrate 21 and forms the conductive pattern 22 is generally copper, but may be a metal such as gold, silver, or aluminum. Similar to the flexible substrate 21, the thickness of the conductive pattern 22 is preferably about half the thickness of the electrode layer of the unit cell layer to be connected in the connection lead portion 24 that is the tip portion of the comb teeth.

  In this embodiment, the conductive pattern 22 is provided on the flexible substrate 21 without an adhesive. However, an adhesive layer may be provided between the conductive pattern 22 and the flexible substrate 21.

  The cover material 23 is a thin film of an insulating resin such as polyimide (PI) or polyethylene terephthalate (PET), like the flexible substrate 21. The cover material 23 is provided on the conductive pattern 22 without an adhesive, but an adhesive layer may be provided between the cover material 23 and the conductive pattern 22.

  The temperature sensor 26 may be a thin film of a resistance material whose resistance value changes depending on the temperature, such as a thermistor, or a thermocouple. As a material whose resistance value changes depending on temperature, a platinum resistance temperature detector, a positive thermal conductor, or a thermal fuse whose resistance value increases drastically when the temperature rises above a specified level may be mounted.

  In the case of using a thermal fuse, as shown in FIG. 13, among the connection lead parts 24 that are the comb tooth tip parts, two or more adjacent to each other, here, the tip parts of the four connection lead parts 24 It is preferable that a thermal relay is configured by arranging a thermal fuse 28 and connecting a pair of lead leads 29 from each thermal fuse 28 in series. That is, the temperature abnormality detection unit 30 is configured by connecting the temperature fuses 28 having one output to a plurality of temperature detection points in series. When the temperature abnormality detection unit 30 in which the temperature fuses 28 are connected in series is installed in this way, when any one of the temperature fuses 28 changes to a high resistance value such as disconnection, that is, some single cell layer 7 Can be detected from an increase in the overall series resistance value. This configuration also has a structure in which the thermal fuse 28 is positioned on the SUS foil of the current collector 2 via the thin connection lead portion 24 and is in good electrical and thermal contact, and the SUS foil of the current collector 2 Since the temperature difference between the temperature sensor 26 and the temperature sensor 26 becomes small, it is possible to detect the temperature abnormality of the single cell layer 7 with high response.

<Fifth Embodiment: FIGS. 14 and 15>
14 to 15 show a fifth embodiment of the present invention. The stacked structure of the single cell layer 7 and the battery element 8 which is a premise is the same as in the case of FIGS. 1 to 3, and the current collector 2 is outside the single cell layer 7 on one side of the peripheral portion of the battery element 8. The separator 6 extends by a length D outside the current collector 2.

  However, the structure of the seal portion is different from that in FIGS. 1 to 4 as follows. That is, although the sealing material 9 is provided on both surfaces of the current collector 2, the sealing material 9 (first sealing material 9 a) on the surface side of the current collector 2 on which the detection element 11 is disposed, and the detection element 11 is different in structure from the sealing material 9 (second sealing material 9b) on the surface side of the current collector 2 where 11 is not disposed.

  That is, on the surface side where the detection element 11 is disposed, that is, on the surface side of the current collector 2 on which the negative electrode layer 4 is formed, the first sealing material 9a is provided on the outer peripheral portion of the negative electrode layer 4 with a predetermined width W4. The current collector 2 and the separator 6 are insulated and sealed. This first sealing material 9a is an insulating layer provided by applying an insulating adhesive in a rectangular frame shape with a predetermined width W4 along the outer periphery of the surface of the rectangular current collector 2 Consists of. Due to the presence of this insulating layer, a non-seal portion 10 having a length L1 is formed in a region outside the first sealing material 9a on the extending portion L of the current collector 2, and the current collector above it is also formed. Between the extending portion L of the electric body 2 and the separator 6, a space portion 10 a into which the leading end portion of the lead wire 12 enters is formed.

  On the other hand, on the surface side where the detection element 11 is not provided, that is, the surface side of the current collector 2 on which the positive electrode layer 3 is formed, the second portion is disposed between the extending portion L of the current collector 2 and the separator 6. The sealing material 9b is provided so as to cover the entire region of the extending portion L in the extending direction width (L) and the extending length D of the separator 6 and to cover the end portion of the separator 6.

  The lead wire 12 handled in the embodiment of FIG. 14 has a structure in which the conductive pattern 22 made of the flexible wiring 20 described in FIGS. 11 and 12 is covered with an insulating coating made of polyimide resin. Further, the flexible wiring 20 has a planar shape, as shown in FIG. 15, the connection lead portion 24 in which the wiring leads are juxtaposed, and the direction of the wiring lead is changed at a right angle and the wiring leads are converged. It has the extension part 25 and the vacuum seal part 27 for sealing the inside and outside when this extension part 25 is pulled out from the exterior 15.

  Now, as described above, between the lower current collector 2 and the upper separator 6 of the negative electrode layer 4 and on the current collector 2, a flexible region is provided in a region outside the negative electrode layer 4 in the plane direction. A space portion 10a in which the tip end portion of the connection lead portion 24 of the wiring 20 is disposed is formed. The width of the space portion 10a in the stacking direction enables the placement or insertion of the connection lead portion 24 at the tip of the flexible wiring 20 and allows the cushioning property to be expressed when pressed in the stacking direction. It is formed larger than the thickness T1.

  Moreover, in order to make it possible to develop cushioning properties when pressed in the stacking direction, a foaming agent is put in the polyimide resin (PI) that constitutes the flexible substrate 21 of the flexible wiring 20. Then, the thicknesses t1 and t2 of the first and second sealing materials 9a and 9b corresponding to the positive electrode layer 3 and the negative electrode layer 4 described above are slightly thicker than the thicknesses T1 and T2 of the positive electrode layer 3 and the negative electrode layer 4. Keep it.

  The connection lead portion 24 of the flexible wiring 20 is arranged in the space portion 10a thus formed.

  In this embodiment, since the combined thickness (t1 + t2) of the first and second sealing materials 9a, 9b is a little thicker than the combined thickness of the positive electrode layer 3 and the negative electrode layer 4 (T1 + T2), When the exterior is formed by two laminated sheet exterior films 15, the atmospheric pressure is applied to the battery element 8 in the laminating direction, and the first and second sealing materials 9a and 9b are pressed and compressed. Also, at the location of the connection lead portion 24 of the flexible wiring 20 inserted into the laminate, the atmospheric pressure of the vacuum seal is concentrated in the lamination direction, and the SUS of the current collector 2 and the connection lead portion 24 are based on the cushioning property. The Cu is pressed in a direction in close contact with each other, and an electrical good connection is made.

  Therefore, according to this pressing contact structure, compared with the case where the voltage measurement lead wire 12 and the temperature measurement lead wire are provided separately, one lead wire 12 can be made common to both, The number of parts is reduced. Further, since it is not necessary to connect the lead wire 12 by ultrasonic welding or soldering, it is possible to reduce connection failure due to soldering failure.

  Further, the connection lead portion 24 of the flexible wiring 20 is pressed by the portion c9c where the second sealing material 9b goes around the tip of the separator 6 on the one hand, and the portion around the tip end of the current collector 2 on the other hand. Since it is pressed by d9d, it is held more firmly. That is, since the flexible wiring 20 has a structure in which a metal conductive pattern 22 is covered with a synthetic resin in advance and firmly bonded, the flexible wiring 20 having this structure is bonded to the plastic portions 9c and 9d of the sealing material 9. By doing so, a large holding strength is ensured.

  In the embodiment of FIGS. 14 and 15, the voltage measurement lead wire 12 is simply provided in the non-seal portion 10. However, the temperature sensor 26 is attached to the connection lead portion 24 of the flexible wiring 20, and the space portion is provided. The connection lead portion 24 of the flexible wiring 20 in which the temperature sensor 26 is incorporated may be arranged in 10a.

  FIG. 16 shows a modified example of FIG. 14 in which a gas release mechanism is incorporated in the seal portion. This gas release mechanism 31 has a region of the separator 6 covered with the first and second sealing materials 9a and 9b, more precisely, a region where the second sealing material 9b is present, and a little of the connection lead portion. In the region up to the tip, the separator 6 is provided with a plurality of small holes 32 penetrating in the thickness direction, and the gas generated in the single cell layer 7 is circulated through the small holes 32, and the connection lead portion 24. The gas pressure can be detected on the side where the gas is present. The pressure sensor for detecting gas generation is preferably provided in the connection lead portion 24, but when it cannot be provided in the connection lead portion 24, it can be incorporated outside the battery element 8.

<Sixth Embodiment: FIGS. 17 to 20>
17 to 20 show other embodiments of the present invention, and FIG. 17 is an external view of the bipolar secondary battery 1. FIG. 18 is a schematic cross-sectional view showing the configuration of the battery element 8 for one stage inside the bipolar secondary battery 1, and FIG. 19 shows a bipolar secondary battery module 33 in which the battery elements 8 are stacked in multiple stages. 17 is a cross-sectional view taken along line AA in FIG. 17, and FIG. 20 is a cross-sectional view taken along line BB in FIG.

  In the bipolar secondary battery 1 of this embodiment, the battery element 8 shown in FIG. 18 is used as one stage, and a total of five battery elements 8 are stacked in five stages through the conductive spacers 34. A bipolar secondary battery module 33 shown in FIG. 19 is configured and covered with an exterior film 15 as shown in FIG.

  The structure of each battery element 8 is the same as that already described with reference to FIGS. 1 to 3. As shown in FIG. 18, the positive electrode layer 3 is formed on one surface of the current collector 2 made of SUS foil. A bipolar electrode 5 having a negative electrode layer 4 formed on the surface is laminated with an electrolyte layer formed by holding an electrolyte in a separator 6 and a plurality of electrodes are arranged in series. A single battery layer 7 is constituted by a structure in which an electrolyte layer is sandwiched between the positive electrode layer 3 and the negative electrode layer 4, and a plurality of single battery layers 7 are laminated to form a battery element 8.

  Further, in the extending portion L of the current collector 2 that extends outward from the unit cell layer 7, a sealing material 9 that insulates between the current collectors 2 is disposed around the unit cell layer 7. . The sealing material 9 is made of an insulating layer provided by applying an insulating adhesive in a rectangular frame shape with a predetermined width W1 on the outer peripheral portion of the surface of the current collector 2. The sealing material 9 is provided on both surfaces of the current collector 2 for each single cell layer so as to insulate the current collectors 2 adjacent to each other in the region of the extending portion L. Yes. Then, on one side of the peripheral portion of the battery element 8, the seal material 9 does not exist as shown by the length L 1 in the extending portion L of the current collector 2 and further on the outer peripheral portion of the seal material 9. A non-seal portion 10 is formed, and a connection lead portion 24 that is a tip portion of the flexible wiring 20 is disposed as the voltage measurement lead wire 12 on the non-seal portion 10 having the length L1. At that time, the connection lead portion 24 of the flexible wiring 20 is electrically connected to the current collector exposed portion 2a using a conductive adhesive.

  As shown in FIG. 19, the battery elements 8 are electrically connected in series via conductive spacers 34 and stacked in multiple stages, and conductive members 35 and 36 for high voltage tabs are provided on the upper and lower sides of the battery elements 8 so as to be bipolar. A type secondary battery module 33 is configured, and an exterior film 15 is provided on the upper and lower sides thereof, thereby being sealed to form the bipolar secondary battery 1. As shown in FIG. 20, the conductive members 35 and 36 are pulled out from the battery exterior in such a manner that the periphery is reinforced with a reinforcing resin 37 and the periphery is sealed with the exterior film 15.

  As shown in FIG. 19, the flexible wiring 20 from each battery element 8 is shifted from the side end of the battery element 8 along the side of the bipolar secondary battery module 33 and stacked on each other. Withdrawing from the exterior film 15 as a monitor tab 16 in a state of being sequentially pulled out without overlapping, and then converging, aligned and covered with a reinforcing resin 38 as shown in FIG.

  In each of the battery elements 8 shown in FIG. 19, current collectors called terminal current collectors are located on the outermost layer (the uppermost part and the lowermost part). In the gap corresponding to the upper and lower thicknesses of the conductive spacer 34 described above, the uppermost one of the connection lead portions 24 of the flexible wiring 20 is located, and this connection lead portion 24 is the uppermost battery element 8 (terminal). It is in electrical contact with the current collector exposed portion 2a of the current collector. In the uppermost part of each battery element 8 and all the cell layers 7 in each battery element 8, a temperature sensor 26 is integrated with the connection lead part 24 on each current collector 2 by using printed wiring technology. Is provided. However, this temperature sensor 26 does not necessarily need to be provided in all the single cell layers 7, but can be provided in one or more of the single cell layers 7 as needed, such as one for each battery element.

  In the present invention, it is sufficient that the non-seal portion 10 on the current collector extending portion L is provided on at least one side of the peripheral portion of the battery element 8. Therefore, in the case of a rectangular dipole electrode as in the above-described embodiment, the non-seal portion 10 is preferably formed only on one side thereof. This is because the volume efficiency of the battery is improved because it is configured with the minimum necessary electrode area. Further, even when the non-adhesive portion 18 is provided on the other side as well due to the handling problem in the lamination process, the width of the non-seal portion 10 is increased only at the side where the lead wire 12 is attached. good.

  The non-seal portion 10 may be formed on at least one surface side of the bipolar electrode 5. This is because the detection element 11 such as the lead wire 12 can be electrically connected to the current collector exposed surface of one current collector 2 belonging to the unit cell layer 7. Although it is not necessary to arrange anything on the other surface as shown in FIG. 1, for example, by extending the sealing material 9 on the other surface, the second sealing material 9b penetrates as shown in FIG. Alternatively, as shown in FIG. 14, the second sealing material 9 b protruding from the separator 6 can fix the lead wire 12. As a result, the lead wire 12 can be held not only by the conductive adhesive material on the bonding surface but also by the sealing material 9.

  Further, in the above-described embodiment, the electrolyte layer is described as an example of the configuration made of the electrolyte held by the separator 6 disposed between the positive electrode layer 3 and the negative electrode layer 4. However, the electrolyte layer is configured without the separator 6. It may be a gel or solid electrolyte layer. However, as in the above embodiment, the electrolyte layer is preferably composed of an electrolyte held in the separator 6 disposed between the positive electrode layer 3 and the negative electrode layer 4, and the separator 6 is an electrode of the positive electrode layer 3 and the negative electrode layer 4. It is preferable to make it larger than the current collector 2 of the layer. This is because the insulation between the bipolar electrodes 5 can be performed by the separator 6 in the lead wire attaching portion, so that the insulation at the outer peripheral portion of the sealing material 9 can be easily secured. For example, in the attachment portion of the lead wire 12 in FIG. 1, since the bipolar electrode 5, the lead wire 12, the separator 6, and the next bipolar electrode 5 are laminated in this order from the bottom, current collection of the upper and lower bipolar electrodes 5 is performed. The bodies 2 do not come into contact with each other at the lead wire attachment portion. Further, since there is no need to newly provide an insulating means, there is an advantage that the configuration can be reduced.

  In the present invention, the minimum configuration when measuring the voltage for each unit cell layer 7 is a configuration in which the tip end portion of the lead wire 12 is arranged on the non-seal portion 10 as the detection element 11. On the other hand, the minimum configuration in the case of measuring temperature is a configuration in which a sensing part in which the temperature sensor 26 is covered with an insulator is provided at the tip of the lead wire 12 and this is provided as the detection element 11 in the non-seal part 10. When the lead wire 12 is the flexible wiring 20, the temperature sensor 26 and the wiring lead are provided in the form of a sensing part in which the temperature sensor 26 and the wiring lead are covered with a thin film insulating material. Conventionally, a temperature sensor covered with a heat-shrinkable tube is fixed to the side surface of the battery exterior or the like with a heat-shrinkable tube, but in comparison with this, in the present invention, the SUS foil of the current collector 2 and the temperature sensor 26 are Since the distance difference is reduced, the temperature difference is reduced, and the battery temperature can be measured with high response. Moreover, vibration durability is dramatically improved by using the flexible wiring 20 dedicated to the bent portion.

  In the above-described embodiment, the temperature abnormality detection unit 30 using the temperature relay and the temperature measurement unit having a one-to-one correspondence output with respect to a plurality of temperature detection points are described as being provided separately. And a temperature measuring unit can be incorporated at the same time, whereby the reliability of the bipolar secondary battery can be improved.

  Moreover, in the structure which the lead wire 12 of this invention consists of the flexible wiring 20, since the back surface of the conductive pattern 22 of metal foil is protected with insulating resin, the metal foil of the conventional electrical power collector 2 is made outside the battery. The bending durability of the lead wire 12 is improved and the vibration durability is dramatically improved as compared with the case where the lead wire 12 is connected to the wiring.

  Further, in the present invention, the flexible wiring 20 in which the conductive pattern 22 is protected by the engineering plastic is drawn from between the heat-sealing seal structures of the exterior film 15. This is because the metal of the conductive pattern 22 and the engineering plastic of the protective coating are bonded in advance, and the flexible wiring 20 having a strong structure is bonded to the plastic. Therefore, the metal and the plastic are separately heat-sealed. It is easier to secure the adhesive strength than the structure.

  Hereinafter, the present invention will be described based on examples. Here, representatively, a method for manufacturing the bipolar secondary battery 1 in which the sealing material 9 described in FIG. 1 is formed on both surfaces of the separator 6 will be described.

<Creation of bipolar electrode 5>
"Positive electrode layer 3"
The following materials were mixed at a predetermined ratio to prepare a positive electrode slurry.

As the positive electrode active material, 85% by weight of LiMn ₂ O ₄ , 5% by weight of acetylene black as the conductive auxiliary agent, 10% by weight of PVDF as the binder, and NMP as the slurry viscosity adjusting solvent are added until the viscosity becomes optimum for the coating process. A slurry was prepared. The positive electrode slurry was applied to one side of a SUS foil (thickness: 20 μm) as the current collector 2 and dried to form a positive electrode layer 3 of 30 μm.

"Negative electrode layer 4"
The following materials were mixed at a predetermined ratio to prepare a negative electrode slurry.

  As a negative electrode active material, 90 wt% of hard carbon, 10 wt% of PVDF as a binder, and NMP as a slurry viscosity adjusting solvent were added until the viscosity became optimum for the coating process to prepare a negative electrode slurry. The negative electrode slurry was applied to the opposite surface of the SUS foil to which the positive electrode slurry was applied, and dried to form a negative electrode layer 4 of 30 μm.

  The bipolar electrode 5 was formed by forming the positive electrode layer 3 and the negative electrode layer 4 on both surfaces of the SUS foil as the current collector 2. These bipolar electrodes 5 were cut to 160 × 130 (mm), and the outer peripheral portions of both the positive electrode layer 3 and the negative electrode layer 4 were peeled off to expose 20 mm, thereby exposing the SUS surface as the current collector 2. Thus, a bipolar electrode 5 having an electrode surface of 120 × 90 (mm) and a 20 mm current collector frame-shaped exposed portion on the outer peripheral portion was produced. At this stage, the voltage measurement lead wire 12 is not yet attached.

<Formation of electrolyte layer>
The following materials were mixed at a predetermined ratio to produce an electrolyte material.

PC-EC 1MLiPF ₆ (90 wt%) as the electrolyte, PVdF-HFP (10 wt%) containing 10% HFP copolymer as the host polymer, and DMC as the viscosity adjusting solvent are added until the viscosity reaches the optimum for the coating process. An electrolyte was prepared. This electrolyte was applied to the positive and negative electrode portions on both sides, and the DMC was dried to complete the bipolar electrode 5 infiltrated with the gel electrolyte.

<Formation of sealing material 9>
Using a dispenser, the sealing material 9 is accurately applied to the non-coated portion (electrode uncoated portion) on the current collector 2 on the periphery of the electrode layer (positive electrode layer 3 and negative electrode layer 4) of the bipolar electrode 5. Applied a one-part uncured epoxy resin as a sealing material precursor. As shown in FIG. 2, the sealing material 9 was applied to the rectangular surface of the current collector 2 in a rectangular frame shape with a predetermined width W1 along the outer peripheral portion thereof. At this time, the connection lead portion 24 of the voltage measurement lead wire 12 serving as the detection element 11 can be arranged on one side of the outer peripheral portion of the sealing material 9 and can be electrically connected to the outer peripheral portion. 10 mm was left as an uncoated portion of the sealing material, that is, the non-sealed portion 10, thereby forming the current collector exposed portion 2 a on the current collector 2. In the present embodiment, among these non-sealed portions 10, the outer non-sealed portion 10 where the first sealing material 9a on the lower side of the separator exists is the portion where the connection lead portion 24 of the voltage measuring lead wire 12 is disposed. It becomes.

Next, a 170 × 140 (mm) separator 6 (polyethylene separator: 12 μm) was placed on the positive electrode layer 3 side so as to cover all the SUS foil as the current collector 2.
<Attachment of voltage measurement lead wire 12>
As described above, when the first sealing material 9a is applied to the peripheral portion of the positive electrode layer 3 of the bipolar electrode 5 on the non-coated portion of the sealing material on the current collector 2, the outer periphery of the first sealing material 9a is applied. A part (non-seal part 10) to be left without applying the sealing material 9 was made in the part. Then, the connection lead portion 24 of the voltage measurement lead wire 12 serving as the detection element 11 was bonded to the non-sealed portion 10 (current collector exposed portion 2a) via a conductive adhesive.

<Lamination of electrodes>
The step of forming the sealing material 9 and the step of attaching the lead wires 12 were repeated a plurality of times to produce a bipolar battery structure in which six layers of bipolar electrodes 5 were arranged.

<Bipolar battery press>
The bipolar battery structure was hot-pressed in a vacuum at a surface pressure of 1 kg / cm 2 and 80 ° C. for 1 hour in a vacuum to cure the uncured sealing material 9 (epoxy resin). By this step, the sealing material 9 can be pressed to a predetermined thickness and further cured.

<Tab extraction structure>
The bipolar battery structure produced as described above was sandwiched between exterior films 15 made of an aluminum laminate exterior material, and the four sides were bonded by thermal fusion. At that time, for the first and second electrode tabs 13 and 14 for taking out the current, first, the first and second conductive members 35 and 36 made of a highly conductive material are all covered with the electrode surfaces, and then From above, it was vacuum-sealed with an aluminum laminate exterior material, and pulled out from the exterior 15 as a conductive tab.

  Further, the flexible wiring 20 was drawn from the exterior film 15 with the extended portion 25 as the monitor tab 16.

<Evaluation>
According to the above manufacturing method, since the region on the current collector 2 that is the attachment surface is the current collector exposed portion 2a, it is easy to attach the connection lead portion 24 of the voltage measurement lead wire 12, and Since the attachment means is performed by adhesion via a conductive adhesive that is simpler than ultrasonic welding, the connection lead portion 24 of the voltage measuring lead 12 can be easily attached. Further, not only the method of attaching the connection lead portion 24 of the voltage measurement lead wire 12 while laminating the single cell layer 7, but also the non-sealed portion 10 even after the single cell layer 7 is laminated and the battery element 8 is configured. The connection lead portion 24 of the voltage measurement lead wire 12 could be attached to the current collector 2 also by the method of inserting using the above space.

It is sectional drawing which shows the structure of a part of battery element of the bipolar secondary battery which concerns on 1st Embodiment. It is a perspective view which shows the structure of a part of battery element of the bipolar secondary battery which concerns on 1st Embodiment. It is a top view which shows the structure of a part of battery element of the bipolar secondary battery which concerns on 1st Embodiment. It is a top view which shows the structure of the bipolar secondary battery which concerns on 1st Embodiment. It is sectional drawing which shows the structure of a part of battery element of the bipolar secondary battery which concerns on 2nd Embodiment. It is a perspective view which shows the structure of a part of battery element of the bipolar secondary battery which concerns on 2nd Embodiment. It is a top view which shows the structure of a part of battery element of the bipolar secondary battery which concerns on 2nd Embodiment. It is sectional drawing which shows the structure of a part of battery element of the bipolar secondary battery which concerns on 3rd Embodiment. It is a perspective view which shows the structure of a part of battery element of the bipolar secondary battery which concerns on 4th Embodiment. It is a top view which shows the structure of a part of battery element of the bipolar secondary battery which concerns on 4th Embodiment. It is a top view of the flexible wiring provided with the temperature sensor used with the bipolar secondary battery of 5th Embodiment. It is sectional drawing of the flexible wiring of FIG. It is the top view which showed the modification of flexible wiring. It is sectional drawing which shows the structure of a part of battery element of the bipolar secondary battery which concerns on 5th Embodiment. It is a top view of the flexible wiring used in FIG. It is the same figure as FIG. 14 which showed the modification of 5th Embodiment. It is a top view of the bipolar secondary battery which concerns on 6th Embodiment. It is sectional drawing which showed a partial structure of the bipolar secondary battery which concerns on 6th Embodiment. It is sectional drawing which follows the AA line of FIG. It is sectional drawing which follows the BB line of FIG.

Explanation of symbols

1 Bipolar secondary battery,
2 current collector,
2a Current collector exposed part,
3 positive electrode active material layer (positive electrode layer),
4 negative electrode active material layer (negative electrode layer),
5 bipolar electrodes,
6 separator,
7 cell layer,
8 battery elements,
9 Sealing material,
9a 1st sealing material,
9b Second sealing material,
9c wraparound part,
9d wrap around,
10 Non-seal part (current collector exposed part),
10a space part,
11 detection elements,
12 Lead wire,
13, 14 Electrode tab,
15 exterior film,
16 Monitor tab,
17 resistors,
18 Non-adhesive part,
19 Bonding part,
20 Flexible wiring,
21 Flexible substrate,
22 conductive pattern,
23 Cover material,
24 connection lead part,
25 Extension part,
26 temperature sensor,
27 Vacuum seal part,
28 Thermal fuse,
29 drawer lead,
30 Temperature abnormality detector,
31 Gas release mechanism,
32 small holes,
33 Bipolar secondary battery module,
34 conductive spacer,
35, 36 conductive member,
37, 38 Reinforcing resin,
L Extension part.

Claims (10)

A plurality of bipolar electrodes in which a positive electrode layer is formed on one surface of a current collector and a negative electrode layer is formed on the other surface are arranged in series with an electrolyte layer interposed therebetween, whereby the positive electrode layer and the electrolyte A bipolar secondary battery comprising a battery element having a laminated structure of a single battery layer having a laminated structure of a negative electrode layer and a negative electrode layer, and a sealing material for insulating between the current collectors provided on an outer periphery of the single battery layer In
The electrolyte layer is composed of an electrolyte held in a separator disposed between the positive electrode layer and the negative electrode layer, and the separator is larger than the current collector,
Providing the current collector on at least one side of the peripheral portion of the battery element with an extending portion extending outward from the positive electrode layer and the negative electrode layer,
Providing the sealing material on the extending portion of the current collector, and forming a non-sealing portion in which the sealing material does not exist on the extending portion of the current collector on the outer peripheral portion of the sealing material;
A bipolar secondary battery, wherein a detection element for voltage measurement or temperature detection is arranged and brought into contact with the non-seal portion. Examples detection element, bipolar secondary battery according to claim 1, wherein a distal end of the lead wire is disposed. The bipolar secondary battery according to claim 2 , wherein a sensing portion in which a temperature sensor is covered with an insulating material is provided at a tip portion of the lead wire. The bipolar secondary battery according to claim 3 , wherein the temperature sensor is one of a thermistor, a platinum resistance temperature detector, a thermocouple, or a thermal fuse. The temperature sensor is composed of a temperature fuse, and a sensing part in which the temperature fuse is covered with an insulating material is provided in a current collector of two or more single cell layers, and these temperature fuses are connected in series to constitute a temperature relay The bipolar secondary battery according to claim 3 , wherein the battery is a bipolar secondary battery. A plurality of bipolar electrodes in which a positive electrode layer is formed on one surface of a current collector and a negative electrode layer is formed on the other surface are arranged in series with an electrolyte layer interposed therebetween, whereby the positive electrode layer and the electrolyte A bipolar secondary battery comprising a battery element having a laminated structure of a single battery layer having a laminated structure of a negative electrode layer and a negative electrode layer, and a sealing material for insulating between the current collectors provided on an outer periphery of the single battery layer In
Providing the current collector on at least one side of the peripheral portion of the battery element with an extending portion extending outward from the positive electrode layer and the negative electrode layer,
Providing the sealing material on the extending portion of the current collector, and forming a non-sealing portion in which the sealing material does not exist on the extending portion of the current collector on the outer peripheral portion of the sealing material;
The contacting by placing the detection element for temperature detection in a non-sealed portion,
As the detection element, a leading end portion of a lead wire is disposed, and a leading end portion of the lead wire is provided with a sensing unit in which a temperature sensor is covered with an insulating material, and the temperature sensor includes a thermal fuse. A bipolar secondary characterized in that a sensing part coated with an insulating material is provided in a current collector of two or more single cell layers, and the temperature fuses are connected in series to constitute a temperature relay battery. The electrolyte layer, the consist electrolyte held in a separator disposed between the positive electrode layer and the negative electrode layer, the bipolar secondary according possible to claim 6, wherein said separator is larger than the previous SL collector Next battery. The bipolar secondary battery according to claim 1, wherein the non-seal portion is provided only on one side of the peripheral portion of the battery element. The bipolar secondary battery according to any one of claims 1 to 8 , wherein a plurality of the non-seal portions are arranged on only one surface of a bipolar electrode arranged in series. A plurality of bipolar electrodes in which a positive electrode layer is formed on one surface of a current collector and a negative electrode layer is formed on the other surface are arranged in series with an electrolyte layer interposed therebetween, whereby the positive electrode layer and the electrolyte A bipolar secondary battery comprising a battery element having a laminated structure of a single battery layer having a laminated structure of a negative electrode layer and a negative electrode layer, and a sealing material for insulating between the current collectors provided on an outer periphery of the single battery layer In
  The electrolyte layer is composed of an electrolyte held in a separator disposed between the positive electrode layer and the negative electrode layer, and the separator is larger than the current collector,
  Providing the current collector on at least one side of the peripheral portion of the battery element with an extending portion extending outward from the positive electrode layer and the negative electrode layer,
  The sealing material is provided on the extending portion of the current collector, and the non-sealing portion where the sealing material does not exist is provided on the extending portion of the current collector on the outer peripheral portion of the sealing material. Bipolar secondary battery.

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