JP5621417B2 - Stack and bipolar secondary battery - Google Patents

Description

This invention relates to the stack and the bipolar secondary battery.

  In a stacked battery, each cell has variations in its internal resistance, capacity, etc. due to manufacturing variations, and therefore, when the cells are connected in series, the voltage of each cell varies. Deterioration progresses from a battery having a large voltage variation, and the life as a stacked battery is limited. Accordingly, it is desirable to equalize the voltages of all the unit cells by measuring the voltage of each unit cell and controlling the voltage of each unit cell based on the measurement result.

  For this reason, a flexible (flexible) wiring board is attached to each current collector in order to measure the voltage of each unit cell of the stacked type battery (bipolar secondary battery), and the voltage of each unit cell is set to the outside. Some have been taken out (see Patent Document 1).

JP 2008-160060 A

  The above wiring board includes an insulating substrate composed of a comb-like portion composed of a plurality of teeth and a stem integrated by bundling the plurality of teeth, and a single handle connected to the comb-like portion, and the insulating substrate. A plurality of wires formed of a conductive material on the substrate and individually extending from the tip of each of the plurality of teeth to the end of the handle and conducting a potential of a conductor contacting the tip of the plurality of teeth to the end of the handle; have. At the tips of the plurality of teeth, there are terminal portions from which the conductive material is exposed, and these terminal portions are attached to corresponding current collectors.

  However, in the above wiring board, the length of a plurality of teeth, the terminal area, and the adhesive force between the terminal and the current collector corresponding to the terminal are all the same. After bonding to the current collector at the same distance from the end portions of the electrode active material provided on the upper and lower surfaces, the degree of sagging of the plurality of teeth is different. For this reason, when the laminated battery is used in an environment in which vibrations occur, relatively large tensile stress acts on teeth that are not relatively loose, compared to teeth that are relatively loose. A tooth to which a relatively large tensile stress acts is more likely to be disconnected than a tooth to which a relatively small tensile stress acts. If disconnection occurs in the wiring board, it becomes impossible to accurately measure the shared voltage of all the cell layers.

Accordingly, the present invention aims at providing the same to be obtained away tack and bipolar secondary battery among a plurality of unit cells of the mounting position of the current collector terminal.

In the present invention, two bipolar electrodes in which a positive electrode is formed on one surface of a current collector and a negative electrode is formed on the opposite surface are stacked with an electrolyte sandwiched so that the positive electrode and the negative electrode face each other. A unit cell composed of a positive electrode and a negative electrode sandwiching an electrolyte, and a stack in which a plurality of the unit cells are connected in series, and a wiring board for voltage detection of each of the plurality of unit cells, and a plurality of teeth An insulating substrate composed of a comb-shaped portion made of a trunk in which the plurality of teeth are bundled and integrated, and a single handle connected to the comb-shaped portion, and the plurality of the conductive substrates formed on the insulating substrate with a conductive material. A plurality of wires that individually extend from the tips of the teeth to the ends of the handle and conduct electrical potentials of the conductors contacting the tips of the teeth to the ends of the handles, and conductive to the tips of the teeth. material is configured to include a terminal portion exposed, each of the plurality of terminals In the stack that is attached to the corresponding current collector, the length of the tooth to be attached to the current collector at a position away from the predetermined first reference position among the plurality of teeth is at the first reference position. Alternatively, the length of the teeth attached to the current collector in the vicinity of the first reference position is made longer, and among the plurality of teeth, the tooth away from the first reference position is made thicker .

According to the present invention, in the stack, the length of the teeth attached to the current collector located at a position away from the predetermined first reference position among the plurality of teeth is at the first reference height or the first reference height. Since it is longer than the length of the tooth attached to the current collector near the height, the current collector located at a position away from the first reference height and at the first reference height or near the first reference height A terminal part can be attached to the current collector at the same position on the peripheral edge of the current collector. As a result, each voltage of the plurality of unit cell layers can be measured with higher accuracy than the case where the wiring board of Comparative Example 1 in which the plurality of teeth have the same length is attached to the stack. In addition, when a stack having a large number of single cell layers connected in series is used in an environment in which vibration is generated, if the thickness of the plurality of teeth of the wiring board is the same, the teeth are separated from the teeth at the first reference position. Since the tensile stress acting on the exposed conductive portion of the terminal portion of the tooth increases with vibration, the wire formed on the insulating substrate may be disconnected. According to the wiring board of the present invention, the teeth away from the first reference position among the plurality of teeth are thickened. That is, by increasing the thickness of the teeth as the tensile stress increases, it is possible to prevent the wiring from being disconnected due to vibration.

It is a schematic longitudinal cross-sectional view of the stack in which the wiring board of the reference example 1 was attached. It is the top view which looked at the stack with which the wiring board of the reference example 1 was attached from the top. It is a longitudinal cross-sectional view of the stack with which the wiring board of the reference example 1 was attached. 4 is a plan view of a wiring board of Comparative Example 1 and a wiring board of Reference Example 1. FIG. It is an enlarged view of only the connection part to the electrical power collector of the 1st, 4th terminal part at the time of attaching the wiring board of the comparative example 1 to a stack. It is an enlarged view of only the connection part to the electrical power collector of the part which was the 1st, 4th terminal at the time of attaching the wiring board of the reference example 1 to a stack. 4 is a simplified model diagram of a wiring board of Reference Example 1. FIG. 6 is a simplified model diagram of wiring boards of Reference Examples 2 , 3 , 4 , and 5. FIG. It is the schematic seen from the wiring board side, when the wiring board of the reference examples 2 and 3 is attached to the stack. It is a simple model figure of the wiring board of the 1st , 2nd , and 3rd embodiment of the present invention . It is a schematic longitudinal cross-sectional view of the bipolar secondary battery with which the wiring board of 4th Embodiment was attached. It is the top view which looked at the bipolar secondary battery with which the wiring board of 4th Embodiment was attached from the top. It is a partially expanded schematic longitudinal cross-sectional view of a bipolar secondary battery. 10 is a plan view of a wiring board of Comparative Example 2. FIG. It is a top view of the wiring board of a 4th embodiment. It is a top view of the wiring board of a 5th embodiment. It is a schematic longitudinal cross-sectional view of the bipolar secondary battery to which the wiring board of 6th Embodiment is attached. It is the top view which looked at the bipolar secondary battery with which the wiring board of 6th Embodiment was attached from the top. It is a top view of the wiring board of a 6th embodiment. It is a top view of the wiring board of a 7th embodiment. It is a schematic longitudinal cross-sectional view of the bipolar secondary battery with which the wiring board of 8th Embodiment was attached. It is the top view which looked at the bipolar secondary battery with which the wiring board of 8th Embodiment was attached from the top. It is a top view of the wiring board of an 8th embodiment. Fourth Embodiment The fourth bipolar mounted a wiring board embodiment including the connection portion between the schematic longitudinal sectional view and external showing a connection state of an external bipolar secondary battery mounted a circuit board It is a general-view figure of a type secondary battery. Ninth Embodiment Ninth bipolar mounted a wiring board embodiment including the connection portion between the schematic longitudinal sectional view and external showing a connection state of an external bipolar secondary battery mounted a circuit board It is a general-view figure of a type secondary battery. 10th 10th bipolar mounted a wiring board embodiment including the connection portion between the schematic longitudinal sectional view and external showing a connection state of an external bipolar secondary battery mounted the wiring board embodiments It is a general-view figure of a type secondary battery. 11th 11th bipolar mounted a wiring board embodiment including the connection portion between the schematic longitudinal sectional view and external showing a connection state of an external bipolar secondary battery mounted the wiring board embodiments It is a general-view figure of a type secondary battery. 12th 12th bipolar attached the wiring board embodiment including the connection portion between the schematic longitudinal sectional view and external showing a connection state of an external bipolar secondary battery mounted the wiring board embodiments It is a general-view figure of a type secondary battery. It is a general-view figure of the bipolar secondary battery with which the wiring board of 13th Embodiment including the connection part with the outside was attached. It is a schematic perspective view of the stack to which the wiring board of Reference Example 1 is attached. It is a schematic side view of the stack with which the wiring board of the reference example 1 was attached. It is a simplified model diagram of the wiring board of the fourteenth and fifteenth embodiments. It is a schematic sectional drawing which shows the attachment state to the electrical power collector of the exposed electrically conductive part of the four terminal parts of 14th Embodiment. It is a schematic sectional drawing which shows the attachment state to the electrical power collector of the exposed electrically conductive part of the four terminal parts of 15th Embodiment. It is a partially expanded schematic longitudinal cross-sectional view of a bipolar secondary battery. It is a perspective view which takes out and shows only two high electric power tabs. It is a top view of the wiring board of a 16th embodiment. It is a schematic sectional drawing which shows the attachment state to the electrical power collector of the exposed electroconductive part of the four terminal parts of the comparative example 1 of 1. It is a schematic sectional drawing which shows the attachment state to the electrical power collector of the exposed electrically conductive part of the four terminal parts of the other comparative example 1. It is a schematic sectional drawing which shows the attachment state to the electrical power collector of the exposed electrically-conductive part of the four terminal parts of the reference example 1 in the case of having an insulating part in the periphery of a terminal part. It is a schematic sectional drawing which shows the attachment state to the electrical power collector of the exposed electrically conductive part of the four terminal parts of the reference example 1 when not having an insulating part in the periphery of a terminal part.

  Embodiments will be described below with reference to the drawings. In the following drawings, in order to facilitate understanding of the invention, the thickness and shape of each layer such as elements constituting the stacked battery are exaggerated.

FIG. 1 is a schematic longitudinal sectional view of a stack 2 to which a wiring board 21 of Reference Example 1 according to the present invention is attached. FIG. 2 is a plan view of a portion of the stack 2 excluding high-voltage tabs 16 and 17 as viewed from above. . The stack 2 is a unit constituting a bipolar secondary battery. In FIG. 1, it is assumed that the upper part is vertically upward and the lower part is vertically downward.

  The rectangular and flat current collector 4 is formed of a resin obtained by adding a conductive filler to a conductive polymer material or a non-conductive polymer material. The current collector 4 is not limited to resin and may be formed of metal. In the stack 2, the positive electrode active material layer 5 (positive electrode) is formed on the vertical lower surface of the current collector 4 placed in the horizontal direction in FIG. 1, and the negative electrode active material layer 6 (negative electrode) is formed on the vertical upper surface of the current collector 4. There are four (plural) bipolar electrodes 3 formed. The negative electrode active material layer 6 has a larger surface area than the positive electrode active material layer 5. Each bipolar electrode 3 is laminated in the vertical direction via an electrolyte layer 7 (connected in series) to form one stack 2.

  Here, when two bipolar electrodes adjacent in the vertical direction are respectively an upper bipolar electrode and a lower bipolar electrode, the negative electrode active material layer 6 positioned on the upper surface of the lower bipolar electrode and the lower surface of the upper bipolar electrode The lower and upper bipolar electrodes are arranged so that the positive electrode active material layer 5 located at the position facing each other through the electrolyte layer 7.

  The outer periphery in the horizontal direction of the two electrode active material layers 5 and 6 of the positive electrode and the negative electrode is formed slightly narrower than the outer periphery in the horizontal direction of the current collector 4. The positive electrode active material layer 5 and the negative electrode are formed by sandwiching a sealing material 11 having a predetermined width around the peripheral portion (horizontal circumference) of the current collector 4 where the two electrode active material layers 5 and 6 are not provided. In addition to insulating the active material layer 6, a predetermined space 8 is formed between the two electrode active material layers 5, 6 facing in the vertical direction in FIG. 1. Further, the sealing material 11 is disposed outside the horizontal end portions of the two active material layers 5 and 6 with a margin.

  The space 8 is filled with a liquid or gel electrolyte 9 to form an electrolyte layer 7.

  The space 8 filled with the electrolyte 9 is provided with a separator 12 formed of a porous film, and the two electrode active material layers 5 and 6 that are opposed by the separator 12 are also prevented from being in electrical contact. Has been. The electrolyte 9 can pass through the separator 12.

For reference, high-power tabs 16 and 17 are shown at positions separated from the stack 2 at the uppermost and lowermost stages of the stack 2. As will be described later, the bipolar secondary battery to which the wiring board of Reference Example 1 is attached is configured by connecting five stacks 2 in series (modularized). In this bipolar secondary battery, one high-power tab 16 is connected to the uppermost negative electrode active material layer 6, and the other high-power tab 17 is connected to the lowermost positive electrode active material layer 5. One high-power tab 16 functions as a positive terminal after charging the bipolar secondary battery, and the other high-power tab 17 functions as a negative terminal after charging.

  A single cell layer 15 (single cell) is constituted by the positive electrode active material layer 5 and the negative electrode active material layer 6 sandwiching the electrolyte layer 7. Therefore, the stack 2 has a configuration in which the three single battery layers 15 are connected in series.

  In FIG. 1, the number of unit cell layers 15 connected in series is three. However, the number of unit cell layers 15 connected in series and the number of stacks to be connected in series depend on the desired voltage in practice. Adjust it.

  Now, if the voltages are not the same in the plurality of single battery layers 15 connected in series, a desired battery voltage cannot be obtained for the entire stack 2. For example, as shown in FIG. 3, four current collectors 4 are formed as a first current collector 4a, a second current collector 4b, a third current collector 4c, and a fourth current collector 4d from below in the vertical direction. The three unit cell layers 15 are distinguished from the vertically lower side as a first unit cell layer 15a, a second unit cell layer 15b, and a third unit cell layer 15c. At this time, the voltage ΔV1 of the first cell layer 15a can be measured from the voltage obtained via the second current collector 4b and the voltage obtained via the first current collector 4a.

  Similarly, the voltage ΔV2 of the second single battery layer 15b is obtained from the voltage obtained via the third current collector 4c and the voltage obtained via the second current collector 4b. The voltage ΔV3 can be measured from a voltage obtained via the fourth current collector 4d and a voltage obtained via the third current collector 4c.

  In the stack 2 that is a stacked battery, the three single cell layers 15a, 15b, and 15c have variations in internal resistance, capacity, and the like due to manufacturing variations, so the three single cell layers 15a, 15b, and 15c are connected in series. When connected, the voltages ΔV1, ΔV2, and ΔV3 of the cell layers 15a, 15b, and 15c vary. This voltage variation includes a case where the voltage of each single cell layer is larger than the reference value and a case where the voltage is smaller than the reference value. Among such voltage variations, deterioration proceeds from a battery having a large voltage variation, and the life as a stacked battery is limited. Accordingly, the voltages ΔV1, ΔV2, and ΔV3 of the three unit cell layers 15a, 15b, and 15c are measured, and the voltages ΔV1, ΔV2, and ΔV3 of the three unit cell layers 15a, 15b, and 15c are controlled based on the measurement results. By doing so, it is desirable to make the voltages ΔV1, ΔV2, and ΔV3 of all the cell layers 15a, 15b, and 15c uniform.

  Therefore, a flexible wiring board is attached to the current collector of each single cell layer 15a, 15b, 15c in order to measure the voltage of each single cell layer 15a, 15b, 15c of the stack 2 which is a stacked battery. Consider that the voltages ΔV1, ΔV2, and ΔV3 of the unit cell layers 15a, 15b, and 15c are taken out to the outside. For example, the wiring board 21 of the comparative example 1 as shown in the upper part of FIG. 4 is prepared. The wiring board 21 of the comparative example 1 has four teeth 21a, 21b, 21c, 21d and a comb-shaped portion 21f composed of a trunk 21e formed by bundling the plurality of teeth, and one connected to the comb-shaped portion 21f. An insulating film 26 (insulating substrate) composed of a handle 21g and a conductive material formed on the insulating film 26 and individually extended from the tips of the four teeth 21a, 21b, 21c, 21d to the end of the handle 21g And it has four wirings 22, 23, 24, and 25 for conducting the electric potential of the conductor contacting the tips of the four teeth to the end of the handle 21g. In addition, in the upper part of FIG. 4, terminal portions 22a, 23a, 24a, and 25a from which the conductive material is exposed are provided at the tips of the four teeth 21a, 21b, 21c, and 21d. A connector (not shown) is provided at the end of the handle 21g (the right end in the upper part of FIG. 4). Note that the handle 21g has a stack 2 (battery) or a bipolar secondary battery 30 to be described later so that the voltages ΔV1, ΔV2, and ΔV3 of the four single battery layers 15a, 15b, and 15c can be measured from the outside. It is necessary that the connector penetrates the exterior material and comes out of the exterior material. For this reason, the handle 21g needs a certain length.

  Specifically, the wiring board 21 is made of an insulating substrate made of a polyimide resin material, a first adhesive layer made of an insulating adhesive, a wiring layer made of copper as a conductor, and an insulating adhesive. Consists of five layers, a second adhesive layer and a cover layer made of polyimide resin material. Copper is exposed on the surface at the terminal portions 22a, 23a, 24a, 25a which are the tips of the four teeth 21a, 21b, 21c, 21d. For this purpose, the second adhesive layer and the cover layer are removed. That is, the four terminal portions 22a, 23a, 24a, and 25a are divided into three layers: an insulating substrate made of a polyimide resin material, a first adhesive layer made of an insulating adhesive, and a wiring layer made of copper as a conductor. Consists of layers. On the other hand, since the wiring board 21 has an insulating substrate made of polyimide, the back surfaces of the four teeth are also covered with an insulating substrate made of a polyimide resin material. The thickness of the four terminal portions 22a, 23a, 24a, and 25a needs to be smaller than the distance between the opposing current collectors.

  The wiring board 21 of the comparative example 1 is attached to each of the three unit cell layers 15a, 15b, 15c of the stack 2 as shown in FIG. 37 and 38 are schematic cross-sectional views showing four terminal portions 22a, 23a, 24a, and 25a of one comparative example 1 and another comparative example 1, respectively. In the first comparative example 1 shown in FIG. 37, the insulating portions 125, 126, 127, and 128 are formed on the periphery of the terminal portions 22a, 23a, 24a, and 25a, and the portions remaining in the center are electrically conductive portions (this conductive portions are It is configured as “exposed conductive portion”) 121, 122, 123, 124. On the other hand, in the other comparative example 1 shown in FIG. 38, the insulating portions 125, 126, 127, and 128 are not formed. The upper side of the wiring board 21 in FIG. 4 is shown with the side where the exposed conductive portion can be seen in front of the page. A conductive tape (described later) is placed on the front side of the exposed conductive portion. Here, in the upper part of FIG. 4, the four terminal portions are distinguished as a first terminal portion 22a, a second terminal portion 23a, a third terminal portion 24a, and a fourth terminal portion 25a. In order to electrically connect the four terminal portions 22a, 23a, 24a, and 25a and the four current collectors 4a, 4b, 4c, and 4d, the following steps are performed. That is, a conductive double-sided tape (hereinafter referred to as “conductive tape”) 111 is placed on the peripheral portion (right end portion in FIGS. 37 and 38) of the first current collector 4 a, and the first current collector 4 a is placed on the conductive tape 111. The exposed conductive portion 121 of the terminal portion 22a is disposed. Then, the sealing material 11 is arrange | positioned on the 1st terminal part 22a, and the 2nd electrical power collector 4b is mounted on it. The conductive tape 112 is placed on the peripheral edge of the second current collector 4b (the right end in FIGS. 37 and 38), and the exposed conductive part 122 of the second terminal portion 23a is disposed on the conductive tape 112. Then, the sealing material 11 is arrange | positioned on the 2nd terminal part 23a, and the 3rd electrical power collector 4c is mounted on it. By repeating these operations, four bipolar electrodes 3 are stacked. Thereafter, the four bipolar electrodes 3 stacked in the thermocompression bonding process are thermocompression bonded. The sealing material 11 is bonded to the current collectors 4a, 4b, 4c, and 4d by thermal welding, and the terminal portions 22a, 23a, 24a, and 25a corresponding to the four current collectors 4a, 4b, 4c, and 4d are exposed. It is electrically connected so as to press the conductive parts 121 to 124. As the sealing material 11, an elastic material such as PEO, PPO, PVdF, epoxy resin, silicon resin, or the like can be used. Stress generated by the difference in thermal expansion coefficient between the current collectors 4a, 4b, 4c, and 4d and the terminal portions 22a, 23a, 24a, and 25a from which copper as the conductor is exposed by using an elastic body as the sealing material 11 Can be removed, and peeling due to temperature change can be prevented.

  By attaching the exposed conductive portions 121 to 124 of the four terminal portions 22a, 23a, 24a, and 25a of the wiring board 21 to the stack 2 in this manner, the exposed conductive portions of the four terminal portions 22a, 23a, 24a, and 25a. The voltage (potential) of the current collectors 4a, 4b, 4c, and 4d, which are measured objects that come into contact with 121 to 124, can be output to the outside through the connector. Thus, by having the connector at the end of the handle 21g, the voltages ΔV1, ΔV2, and ΔV3 of the three single cell layers 15a, 15b, and 15c can be measured with a compact and small man-hour.

  More specifically, in the two wiring boards 21 of each comparative example 1, in addition to the area where the four conductive tapes 111 to 114 adhere to the exposed conductive parts 121 to 124, the four teeth 21a, 21b, 21c, The length and thickness of 21d, the area of the four terminal portions 22a, 23a, 24a, and 25a, and the bonding area of the four conductive tapes 111 to 114 are all the same.

  Here, since the thickness of the teeth is a concept including the width and thickness of the teeth, the width and thickness of the teeth are individually defined. The tooth width is the vertical width of the teeth 21a, 21b, 21c, 21d in the upper part of FIG. Further, in the upper part of FIG. 4, the teeth 21 a, 21 b, 21 c, 21 d have a thickness in a direction penetrating the paper surface. The thickness of the teeth refers to the thickness of the teeth 21a, 21b, 21c, 21d in the direction penetrating the paper surface. If the thickness of the teeth is the same, the teeth can be thickened by increasing the width of the teeth. Moreover, if the width of the teeth is the same, the teeth can be thickened by increasing the thickness of the teeth. When the wiring board 21 is attached to the stack 2, the vertical direction shown in the upper part of FIG. 4 is parallel to the surface of the current collectors 4a to 4d, and the direction passing through the paper surface in the upper part of FIG. It becomes. Therefore, when the wiring board 21 is attached to the stack 2, each of the four teeth 21a, 21b, 21c, 21d has a predetermined thickness in the stacking direction of the unit cell layers (in the series direction of the unit cells), and the surface of the current collector And having a predetermined width in a direction parallel to.

Further, in reference examples 1 to 5 and first to third embodiments described later , the area of the terminal portion (this area is also referred to as “terminal portion area” hereinafter) refers to the area of one terminal portion. The total area of the two terminal parts is not required. In the fourth to fourteenth embodiments to be described later, the terminal portion area of one entire wiring board, that is, the area of the four terminal portions may be collectively referred to as a terminal portion area. The terminal area is the area including the insulating part when the terminal part has an insulating part (see FIG. 37), and the terminal part has no insulating part (see FIG. 38). ) Refers to the area not including the insulating portion. The exposed conductive part area means the area of the exposed conductive part only, excluding the insulating part when the terminal part has an insulating part (see FIG. 37). When the insulating portion is not provided on the periphery of the terminal portion (see FIG. 38), the exposed conductive portion area matches the terminal portion area. On the other hand, the adhesion area refers to an area where the conductive tape is in contact with the exposed conductive part (also an area where the conductive tape is in contact with the current collector). In simple terms, the area of the conductive tape is the bonding area. The adhesive force between the terminal portion and the current collector depends on the adhesive area, and the adhesive force between the terminal portion and the current collector increases as the adhesive area increases. The adhesive force between the terminal portion and the current collector does not increase simply by increasing the exposed conductive portion area while keeping the area of the conductive tape as it is.

  In the upper part of FIG. 4, conductive tapes 111, 112, 113, and 114 are shown superimposed on the exposed conductive parts 121, 122, 123, and 124 of the terminal portions 22a, 23a, 24a, and 25a. However, since it becomes difficult to see when the conductive tape and the exposed conductive portion of the terminal portion are overlapped, the conductive tapes 111 to 114 are described slightly smaller than the exposed conductive portion of the terminal portion. In practice, as shown in FIGS. 37 and 38, the adhesive area of the conductive tapes 111 to 114 is the same as the exposed conductive part area of the terminal part. Note that the adhesive area of the conductive tape is not necessarily the same as the exposed conductive area of the terminal portion, and the adhesive area of the conductive tape may be slightly larger or slightly smaller than the exposed conductive area of the terminal portion. Absent. In this case, the four conductive tapes 111 to 114 are distinguished as a first conductive tape 111, a second conductive tape 112, a third conductive tape 113, and a fourth conductive tape 114.

  Here, the adhesive force between the terminal portion and the current collector corresponding to the terminal portion (hereinafter also simply referred to as “adhesive force between the exposed conductive portion of the terminal portion and the current collector”) is a conductive tape. It depends on the adhesion area and adhesion method of 111-114. With the same bonding method, the larger the bonding area, the stronger the adhesion. If the bonding area is the same, the bonding force varies depending on the bonding method.

  At least one of a conductive member, ultrasonic welding, and thermocompression bonding is used for bonding the current collectors 4a to 4d formed of resin and the exposed conductive portions 121 to 124 of the terminal portions 22a, 23a, 24a, and 25a. . This is because when the exposed conductive portions 121 to 124 of the terminal portions 22a, 23a, 24a, and 25a are bonded to the resin current collectors (members) 4a to 4d having a larger contact resistance than the current collector made of metal. The contact resistance between the resin current collector and the exposed conductive portions 121 to 124 of the terminal portion can be reduced by bonding using a conductive member, mechanical bonding, or bonding using heat. It is. It is preferable that the contact resistance is 1Ω or less after the resin current collector and the exposed conductive portions 121 to 124 of the terminal portion are bonded.

  Examples of the conductive member include a conductive tape, a conductive adhesive paste, a conductive thermosetting sealing material, a conductive thermoplastic sealing material, and an anisotropic conductive adhesive. A generally used material may be used for the conductive tape. For example, there is one in which conductive filler is dispersed in an acrylic tape. The conductive filler includes carbon and metal particles such as Fe, Ni, Al, Ag, Au, and Cu. As a bonding method of the conductive tape, there is a laminating method. Examples of the method for applying the anisotropic conductive adhesive include die coating, screen printing, and inkjet printing.

  Thus, in the two wiring boards 21 of each comparative example 1, the length and thickness of the four teeth 21a, 21b, 21c, and 21d, and the terminal area of the four terminal portions 22a, 23a, 24a, and 25a Since the four exposed conductive portion areas and the four adhesive tapes 111 to 114 have the same bonding area, the exposed conductive portions 121 to 124 of the terminal portions 22a, 23a, 24a, and 25a are connected to the corresponding current collectors. When attaching to the bodies 4a, 4b, 4c, 4d, the terminal portions 22a, 23a, 24a, from the ends (right ends in FIG. 3) of the electrode active material layers 5, 6 provided on the upper and lower surfaces of the current collector The distance to the mounting position of the exposed conductive parts 121 to 124 of 25a may vary. The charges generated in the electrode active material layers 5 and 6 are exposed from the end portions of the electrode active material layers 5 and 6 through the current collectors 4a, 4b, 4c, and 4d, and exposed conductive portions of the terminal portions 22a, 23a, 24a, and 25a. Move to 121-124. For this reason, the internal resistance of the current collector portion where the charge moves as the distance between the end portions of the electrode active material layers 5 and 6 and the mounting positions of the exposed conductive portions 121 to 124 of the terminal portions 22a, 23a, 24a, and 25a increases. (Electric resistance) increases. The influence of this internal resistance becomes more remarkable especially in the resin current collector. That is, even if the voltages ΔV1, ΔV2, and ΔV3 of the three unit cell layers 15a, 15b, and 15c are normal, the positions of the exposed conductive portions 121 to 124 of the four terminal portions 22a, 23a, 24a, and 25a are attached. The three voltages ΔV1, ΔV2, and ΔV3 cannot be accurately measured due to the influence of the voltage drop caused by the variation.

  This will be described with reference to FIG. Here, in FIG. 3, the four teeth 21a, 21b, 21c, and 21d are distinguished from the bottom as the first tooth 21a, the second tooth 21b, the third tooth 21c, and the fourth tooth 21d. Further, the four wirings 22, 23, 24, and 25 are distinguished as a first wiring 22, a second wiring 23, a third wiring 24, and a fourth wiring 25. FIG. 5 shows a connection portion in which the exposed conductive portion 121 of the first terminal portion 22a in FIG. 3 is connected to the first current collector 4a via the first conductive tape 111 and the exposed conductive portion 124 of the fourth terminal portion 25a. Only the connecting portion connected to the fourth current collector 4d via the fourth conductive tape 114 is shown in an enlarged manner, and the exposed conductive portion 122 of the second terminal portion 23a is shown as the second current collector via the second conductive tape 112. The connecting portion connected to the electric current collector 4b and the connecting portion connecting the exposed conductive portion 123 of the third terminal portion 24a to the third current collector 4c via the third conductive tape 113 are not shown.

  In FIG. 5, the charge in the negative electrode active material layer 6a on the upper surface of the first current collector 4a located below is transferred from the first conductive tape 111 to the exposed conductive part 121 of the first terminal portion 22a via the first current collector 4a. In addition, the charge of the negative electrode active material layer 6d on the upper surface of the fourth current collector 4d located above in FIG. 5 is exposed from the fourth conductive tape 114 to the fourth terminal 25a through the fourth current collector 4d. Flow to section 124. As described above, each of the first and fourth current collectors 4a and 4d is formed of a resin in which a conductive filler is added to a conductive polymer material or a non-conductive polymer material, instead of a metal. That is, in the case of the resin current collector, the current collector portion where the charge moves has a larger internal resistance (electric resistance) than the current collector formed of metal. Therefore, the two terminal portions 22a and 25a have the same distance from the right ends of the two negative electrode active material layers 6a and 6d to the exposed conductive portions 121 and 124 of the two terminal portions 22a and 25a. Ideally, the exposed conductive portions 121 and 124 are attached to the corresponding current collectors 4a and 4d via the conductive tapes 111 and 114, respectively.

  However, in the case of the wiring board 21 of Comparative Example 1 shown in the upper part of FIG. 4, the mounting position of the exposed conductive portion 121 of the first terminal portion 22a positioned below in FIG. The exposed conductive portion 124 of the fourth terminal portion 25a located can be attached to the right side of the reference attachment position. As described above, when the exposed conductive portion 124 of the fourth terminal portion 25a is attached to the right side of the reference attachment position, the current collector that moves the charge by the length of the current collector portion to which the charge moves becomes longer. Increases the electrical resistance of body parts. Even if the amount of electric charge (current value) flowing out from the upper and lower negative electrode active material layers 6a and 6d is the same, the voltage drop increases due to the increase in electric resistance. That is, when the voltage of the fourth current collector 4d is measured by the fourth conductor 25, the voltage is lowered from the expected voltage by the increase in the voltage drop of the fourth current collector 4d. As a result, the voltage ΔV3 of the third cell layer 15c is estimated to be apparently larger than the expected voltage. Even if there is no abnormality in the battery characteristics of the third cell layer 15c, the mounting position of the exposed conductive portion 124 of the fourth terminal portion 25a is distant from the reference mounting position in this way, so that the third cell layer 15c If the battery characteristics are abnormal, it will be misdiagnosed.

  Although FIG. 5 illustrates the case where the mounting position of the exposed conductive portion 124 of the fourth terminal portion 25a deviates to the right from the reference mounting position, the exposed conductive portions 122 and 123 of the second and third terminal portions 23a and 24a are described. There may be a case where the attachment position is also shifted to the right side from the reference attachment position. In addition, the tendency of the voltage of the current collector to decrease as it goes upward due to the influence of the mounting position of the exposed conductive portion of the terminal portion is as the thickness increases in the stacking direction of the single cell layers (vertical direction in FIG. 3) or The larger the number of layers stacked, the greater. Even if there is no abnormality in the battery performance of each of the three unit cell layers 15a, 15b, 15c, according to the wiring substrate 21 of Comparative Example 1 shown in the upper part of FIG. 4, the three unit cell layers 15a, 15b, 15c Variations occur in the voltages ΔV1, ΔV2, and ΔV3.

Therefore, in the wiring board 21 of Reference Example 1 , unlike the wiring board 21 of Comparative Example 1, the height (position) of the handle 21g when the wiring board 21 is attached to the stack 2 is set as shown in the lower part of FIG. Based on the standard, the teeth that are farther in the vertical direction from the handle 21g are made longer in tooth length. Note that the height (position) of the handle 21g is not limited to the reference. For example, any height (position) of four teeth 21a, 21b, 21c, and 21d other than the handle 21g may be used as a reference. Any height (position) may be used as a reference. In the following reference examples and embodiments, a case where an insulating portion is provided on the periphery of the terminal portion will be mainly described. In this case, the area of the exposed conductive part is increased when the terminal part area is increased. Note that the case where the insulating portion is not provided at the periphery of the terminal portion is still the subject of the present invention. For example, FIG. 39 shows a state where the exposed conductive portions 121 to 124 of the four terminal portions of the wiring board are attached to the stack when the peripheral portion of the terminal portion has an insulating portion. In this case, the state where the exposed conductive portions 121 to 124 of the four terminal portions of the wiring board are attached to the stack is only as shown in FIG.

The wiring board 21 of the reference example 1 will be specifically described. 4 is a plan view of the wiring substrate 21 of Reference Example 1. FIG. Also in the lower part of FIG. 4, the wiring substrate 21 is shown with the side where the exposed conductive portion can be seen in front of the drawing. Then, conductive tapes 111 to 114 are placed on the front side of the exposed conductive portion on the paper surface. In the state where the wiring board 21 is attached to the stack 2, the upper part is vertically upward and the lower part is vertically downward in the lower part of FIG. 4. In the following, in the lower part of FIG. .

  Here, when the wiring board 21 is attached to the stack 2, the height of the first tooth 21a is the first reference height (first reference position), the length of the first tooth 21a is the first reference length L1, The width (thickness) of one tooth 21a is the first reference width W1, the exposed conductive portion area of the exposed conductive portion 121 of the first terminal portion 22a is the first reference area S1, and the bonding area of the first conductive tape 111 is the first reference. Let it be a bonding area Sad1. At this time, the second tooth 21b is longer than the first reference length L1, the third tooth 21c is longer than the second tooth 21b, and the fourth tooth 21d is longer than the third tooth 21c. Make it longer than the length. The widths of the second, third, and fourth teeth 21b, 21c, and 21d are the same as the first reference width W1, and the exposed conductive portions 122 and 123 of the second, third, and fourth terminal portions 23a, 24a, and 25a are used. , 124 is the same as the first reference area S1, and the bonding areas of the second, third, and fourth conductive tapes 112, 113, 114 are the same as the first reference bonding area Sad1.

In order to attach the wiring board 21 of the reference example 1 configured as described above to the stack 2, first, as shown in FIG. 39, the exposed conductive portion 121 of the first terminal portion 22 a is used as a reference on the first current collector 4 a. The first conductive tape 111 is adhered (attached) to the attachment position. Next, since the difference in length between the second tooth 21b and the first tooth 21a becomes a margin, the exposed conductive portion 122 of the second terminal portion 23a is used as the second current collector 4b using the margin. The second conductive tape 112 is used for bonding at the reference mounting position. Similarly, since the difference in length between the third tooth 21c and the second tooth 21b becomes an allowance, the exposed conductive portion 123 of the third terminal portion 24a is connected to the third current collector 4c using the allowance. The third conductive tape 113 is used to adhere to the reference attachment position above. Similarly, since the difference in length between the fourth tooth 21d and the third tooth 21c becomes a margin, the exposed conductive portion 124 of the fourth terminal portion 25a is connected to the fourth current collector 4d using the margin. The fourth conductive tape 114 is used to adhere to the reference attachment position above.

  Further explanation will be given. The exposed conductive portions 121, 122, 123, and 124 of the four terminal portions 22a, 23a, 24a, and 25a are in contact with the corresponding current collectors 4a to 4d through the conductive tapes 111, 112, 113, and 114, respectively. Increasing the exposed conductive portion area of the exposed conductive portion of the terminal portion and the adhesive area of the conductive tape as described later means that the contact area between the exposed conductive portion of the terminal portion and the current collector is increased. . In this case, if the contact area is changed, the contact resistance between the exposed conductive portion of the terminal portion and the current collector may change from before the change. That is, there are cases where the contact resistance becomes larger than before the change and when it becomes smaller. For this reason, the contact resistance may vary among the exposed conductive portions of the five terminal portions. Under the influence of this variation in contact resistance, the voltage of each current collector cannot be measured with high accuracy. In order to cope with this, when the exposed conductive part area of the terminal part is increased from the first reference area S1 and the adhesive area of the conductive tape is increased from the first reference adhesive area Sad1, the contact resistance becomes the first reference area. It is measured in advance whether or not the area S1 and the first reference adhesion area Sad1 are changed, and when the contact resistance changes from the first reference area S1 and the first reference adhesion area Sad1, the change is included. What is necessary is just to correct | amend the voltage from four electrical power collectors to be measured with a corresponding voltage.

Thus, according to the wiring board 21 of the reference example 1 , the length of the four teeth 21a, 21b, 21c, and 21d is increased in order from the outermost teeth, so that each of the four current collectors 4a, The four terminal portions 22a, 23a, 24a, and 25a can be attached to the same attachment position (reference attachment position) on 4b, 4c, and 4d.

FIG. 6 shows that when the wiring substrate 21 of Reference Example 1 is used, the exposed conductive portions 121 and 124 of the first and fourth terminal portions 22a and 25a are connected via the first and fourth conductive tapes 111 and 114, respectively. 1, only the connecting portion connected to the fourth current collectors 4a and 4d is shown in an enlarged manner, and the exposed conductive portions 122 and 123 of the second and third terminal portions 23a and 24a are shown as second and third conductive materials. Connection portions connected to the second and third current collectors 4b and 4c via the tapes 112 and 113 are not shown. As shown in FIG. 6, in the case of the wiring substrate 21 of Reference Example 1 , the mounting position of the exposed conductive portion 124 of the fourth terminal portion 25a on the fourth current collector 4d is the same as the reference mounting position. . If the mounting positions are the same, the electrical resistance of the current collector portion where the charge moves from the negative electrode active material layer 6d to the exposed conductive portion 124 of the fourth terminal portion 25a via the fourth conductive tape 114 is negative electrode active. The same voltage drop occurs as the electrical resistance of the current collector portion where the charge moves from the material layer 6a to the exposed conductive portion 121 of the first terminal portion 22a through the first conductive tape 111. As a result, variations in the voltages ΔV1, ΔV2, and ΔV3 of the three unit cell layers 15a, 15b, and 15c are reduced, and the voltages ΔV1, ΔV2, and ΔV3 of the three unit cell layers 15a, 15b, and 15c can be accurately measured. .

FIG. 30 is a schematic perspective view of the stack 2 to which the wiring board 21 of Reference Example 1 is attached. FIG. 31 is a schematic side view of the stack 2 as viewed from the side where the wiring board 21 of Reference Example 1 is attached. In FIGS. 30 and 31, only four current collectors 4a, 4b, 4c, and 4d are shown. As shown in FIGS. 30 and 31, it can be seen that the trunk 21 e of the wiring board is positioned slightly inclined from the first reference height.

  In the lower part of FIG. 4, the right end of the handle 21g is connected to a connector (not shown). As described above, this connector penetrates the exterior material and comes out of the exterior material, and can be connected to other devices via this connector.

FIG. 7A is a simplified model diagram showing the wiring board 21 of the reference example 1 shown in the lower part of FIG. 4 again. In FIG. 7A, the first terminal portion 22a is drawn wider than the first reference width W1, which is the width of the first tooth 21a, for convenience. As described above, in the simplified model diagram of the wiring board 21, the width of the teeth excluding the terminal portion is defined as the tooth width. In FIG. 7A, the handle 21g is provided at the position closest to the first reference height, but the height (position) at which the handle 21g is provided may be basically anywhere. For example, as shown in FIG. 7B, the handle 21g may be in the middle of the stacking direction of the single cell layers (vertical direction in FIG. 7). The wiring board 21 in FIG. 7A is shown with the side on which the exposed conductive portions 121 to 124 can be seen in front of the page. The insulating part at the periphery of the terminal part is not shown. The conductive tapes 111 to 114 are placed on the front side of the exposed conductive portions 121 to 124 in the drawing. When the conductive tapes 111 to 114 and the terminal portions 22a, 23a, 24a, and 25a (exposed conductive portions 121 to 124) are overlapped, it becomes difficult to see the conductive tapes 111 to 114, and the conductive tapes 111 to 114 are exposed to the terminal portions 22a, 23a, 24a, and 25a (exposed). It is described slightly smaller than the conductive parts 121-124). Actually, the adhesion area of the conductive tapes 111 to 114 is the same as the area of the exposed conductive parts 121 to 124 of the terminal parts 22a, 23a, 24a, and 25a (see FIG. 7C).

  Note that the wiring board of the simplified model diagrams (FIG. 7B, FIG. 8, FIG. 10, FIG. 14, FIG. 15, FIG. 16, FIG. 19, FIG. 20, FIG. 23, and FIG. The side where the exposed conductive portion can be seen is shown on the front side of the drawing. The insulating part at the periphery of the terminal part is not shown. However, in the simplified model diagrams shown in FIG. 8 and subsequent figures (excluding FIG. 32), the description of the conductive tape is omitted, but this does not mean that the conductive tape is not used. In the following, except for FIG. 32, the conductive tape is not particularly mentioned, but the exposed conductive material of the terminal portion is formed using a conductive tape having the same area (or an approximate area) as the exposed conductive portion area of the exposed conductive portion of the terminal portion. And the current collector are bonded to each other.

Next, another reference wiring board 21 attached to the stack 2 will be described. The characteristic part of the wiring board 21 of the present invention is that the lengths of the four teeth 21a, 21b, 21c, and 21d are made different. As a basic idea in this case, the tooth length at the first reference height is used as a reference (first reference length L1), and the length of the tooth positioned at a height different from the first reference height is set as the first reference height L1. It is to make it longer than one reference length L1. As shown in FIGS. 7A and 7B, it is not always necessary to increase the tooth length as the tooth is further away from the first reference height.

FIGS. 8A to 8D are simplified model diagrams showing the wiring board 21 of Reference Examples 2 to 5 , and replace the wiring board 21 of Reference Example 1 shown in FIGS. 7A and 7B. Is. In the wiring board 21 of Reference Example 2 shown in FIG. 8A, the fourth teeth 21d are teeth at the first reference height, and the fourth teeth 21d, the third teeth 21c, the second teeth 21b, and the first teeth 21a. The tooth length becomes longer in the order. In the wiring board 21 of Reference Example 3 shown in FIG. 8B, the third teeth 21c are teeth at the first reference height, and the third teeth 21c, the first teeth 21a, the second teeth 21b, and the fourth teeth 21d. The tooth length becomes longer in the order. In the wiring board 21 of Reference Example 4 shown in FIG. 8C, the third teeth 21c are teeth at the first reference height, and the third teeth 21c, the second teeth 21b, the fourth teeth 21d, and the first teeth 21a. The tooth length becomes longer in the order. In the wiring board 21 of Reference Example 5 shown in FIG. 8D, the first teeth 21a are teeth at the first reference height, and the first teeth 21a, the fourth teeth 21d, the third teeth 21c, and the second teeth 21b. The tooth length becomes longer in the order.

As described above, it is not always necessary to increase the length of teeth as far away from the teeth at the first reference height, and the wiring boards 21 of Reference Examples 3 to 5 shown in FIGS. The lengths of all four teeth 21a, 21b, 21c, 21d can be set to optimum lengths without sagging.

For example, in the wiring board 21 of Reference Example 3 shown in FIG. 8B, it is possible to attach the four teeth without sagging. For example, the exposed conductive portion 121 of the terminal portion 22a of the first tooth 21a is the first current collector 4a, the exposed conductive portion 122 of the terminal portion 23a of the second tooth 21b is the fourth current collector 4d, and the third tooth 21a. The exposed conductive portion 123 of the terminal portion 24a is not sagging by attaching the exposed conductive portion 124 of the terminal portion 25a of the fourth tooth 21d to the second current collector 4b. However, the method for measuring the voltage of the single cell layer in this case is as follows. That is, the voltage ΔV1 of the first cell layer 15a is measured by the voltage obtained from the exposed conductive portion 121 of the terminal portion 22a of the first tooth 21a and the voltage obtained from the exposed conductive portion 124 of the terminal portion 25a of the fourth tooth 21d. To do. The voltage obtained from the exposed conductive portion 124 of the terminal portion 25a of the fourth tooth 21d and the voltage obtained from the exposed conductive portion 123 of the terminal portion 24a of the third tooth 21c are set to a voltage voltage ΔV2 of the second cell layer 15b. The voltage ΔV3 of the third cell layer 15c is measured from the voltage obtained from the exposed conductive portion 123 of the terminal portion 24a of the three teeth 21c and the voltage obtained from the exposed conductive portion 122 of the terminal portion 23a of the second tooth 21b.

FIGS. 9A and 9B are schematic longitudinal cross-sectional views as viewed from the side of the wiring board 21 when the wiring boards 21 of Reference Examples 2 and 3 shown in FIGS. 8A and 8B are attached to the stack 2. FIG. In the wiring board 21 of Reference Example 2, four teeth 21a as shown in FIG. 9 (a), 21b, 21c , although the exposed conductive parts 121 to 124 of 21d are aligned diagonally position, Reference Example 3 In the wiring substrate 21 shown in FIG. 9, the exposed conductive portions 121 to 124 of the four teeth 21a, 21b, 21c, and 21d are not aligned as shown in FIG. 9B. As described above, the exposed conductive portions 121 to 124 of the four teeth 21a, 21b, 21c, and 21d are not necessarily aligned. Note that the wiring board 21 of Reference Example 3 is attached as shown in FIG. 9B to prevent the four teeth from sagging.

Here, the effect of the wiring board 21 of the reference examples 1-5 is demonstrated .

According to the wiring board 21 of the reference examples 1 to 5, the comb including the four teeth 21a, 21b, 21c, 21d and the trunk 21e in which the four teeth 21a, 21b, 21c, 21d are bundled and integrated. An insulating substrate 26 composed of a ring-shaped portion 21f and a handle 21g connected to the comb-shaped portion 21f, and four teeth 21a, 21b, 21c, 21d formed of a conductive material on the insulating substrate 26. A plurality of wires 22, 23, 24, 25 that individually extend from each tip to the end of the handle 21 g and conduct the potential of the conductor contacting the tip of the four teeth to the end of the handle 21 g, and four teeth 21 a, Terminal portions 22a, 23a, 24a, 25a from which conductive material is exposed at the tips of 21b, 21c, 21d, and the lengths of the four teeth 21a, 21b, 21c, 21d are different. The When attaching to the battery pack 2, the exposed conductive portions 121 of the four terminal portions 22a, 23a, 24a, and 25a with respect to the three (plural) unit cell layers 15a, 15b, and 15c that are components of the stacked battery. ˜124 can be attached at the same position on the peripheral edge of the current collector. As a result, each voltage ΔV1 of the three cell layers 15a, 15b, and 15c (single cell) is larger than that of the wiring board of Comparative Example 1 in which the four teeth 21a, 21b, 21c, and 21d have the same length. , ΔV2 and ΔV3 can be measured with high accuracy.

According to the wiring board 21 of the reference examples 1 and 2 , the lengths of the four (plural) teeth 21a, 21b, 21c, and 21d as shown in FIGS. 7 (a), 7 (b), and 8 (a). Is increased in order from the outermost teeth 21a or 21d, so that when the wiring board 21 is attached to the stack 2, the three (multiple) unit cell layers 15a, 15b, and 15c that are constituent elements of the stacked battery are used. Thus, the exposed conductive portions 121 to 124 of all four terminal portions 22a, 23a, 24a, and 25a can be attached to the same position of the current collector peripheral portion without waste. As a result, the voltages ΔV1, ΔV2, and ΔV3 of the three unit cell layers 15a, 15b, and 15c can be accurately measured while eliminating waste.

On the other hand, the stack 2 to which the wiring board 21 of Reference Example 1 is attached has the positive electrode active material layer 5 (positive electrode) on the lower surface (one surface) of one current collector and the negative electrode active material on the upper surface (opposite surface). The two bipolar electrodes 3 forming the layer 6 (negative electrode) are stacked with the electrolyte 7 interposed therebetween so that the positive electrode active material layer 5 and the negative electrode active material layer 6 face each other, thereby positive electrode active with the electrolyte 7 interposed therebetween. A stack 2 in which a single cell layer 15 (single cell) composed of a material layer 5 and a negative electrode active material layer 6 is formed and three (plural) single cell layers 15 are connected in series, The wiring board 21 for measuring the voltage of the battery layers 15a, 15b, 15c is integrated by bundling the four (plural) teeth 21a, 21b, 21c, 21d and the plural teeth 21a, 21b, 21c, 21d. A comb-shaped portion 21f made of the trunk 21e and a contact with the comb-shaped portion 21f An insulating film 26 (insulating substrate) composed of a single handle 21g and an end of the handle 21g formed from a conductive material on the insulating film 26 from the tips of the four teeth 21a, 21b, 21c, 21d. 4 wires 22, 23, 24, 25 and 4 teeth 21 a, 21 b, each of which is individually extended to conduct the electric potential of the conductor contacting the tips of the four teeth 21 a, 21 b, 21 c, 21 d to the end of the handle 21 g , 21c, and 21d including terminal portions 22a, 23a, 24a, and 25a from which the conductive material is exposed, and four terminal portions 22a, 23a, 24a, and 25a (exposed conductive portions 121 to 124). The stack is attached to the corresponding current collectors 4a, 4b, 4c, and 4d. In the stack 2, the teeth 21 b attached to the current collectors 4 b, 4 c, 4 d located at a position away from a predetermined first reference height (first reference position) among the four teeth 21 a, 21 b, 21 c, 21 d , 21c and 21d are made longer than the length of the teeth 21a attached to the current collector 4a at the first reference height (or near the first reference height), so that they are separated from the first reference height. The current collectors 4b, 4c, 4d at the position and the current collector 4a at the first reference height (or near the first reference height) at the same position on the peripheral edge of the current collector ( Can be attached. As a result, each voltage of the three unit cell layers 15a, 15b, and 15c is higher than the case where the wiring board 21 of Comparative Example 1 having the same length of the four teeth 21a, 21b, 21c, and 21d is attached to the stack 2. ΔV1, ΔV2, and ΔV3 can be accurately measured.

According to the wiring board 21 of the reference examples 1 and 2 , since the teeth away from the first reference height (first reference position) among the four teeth 21a, 21b, 21c, and 21d, the tooth length is increased ( (See FIGS. 7A, 7B and 8A) Exposed conduction of all four terminal portions 22a, 23a, 24a and 25a with respect to the four current collectors 4a, 4b, 4c and 4d. It becomes possible to attach the parts 121 to 124 to the same position on the peripheral edge of the current collector without waste. As a result, variations in the voltages ΔV1, ΔV2, and ΔV3 of the three unit cell layers 15a, 15b, and 15c are reduced while eliminating waste, and the voltages ΔV1, ΔV2, and ΔV3 of the three unit cell layers 15a, 15b, and 15c are reduced. Can be measured with high accuracy.

According to the wiring board 21 of the reference examples 1 and 2 , the attachment positions of the terminal portions 22a, 23a, 24a, and 25a (exposed conductive portions 121 to 124) to the current collectors 4a, 4b, 4c, and 4d are positive electrode active. Since it is located at the same distance from the end (right end in FIG. 3) of the material layer 5 (positive electrode) or the negative electrode active material layer 6 (negative electrode), the four current collectors 4a, 4b, 4c, and 4d The exposed conductive portions 121 to 124 of all four terminal portions 22a, 23a, 24a, and 25a can be attached at the same position on the peripheral portion of the current collector, and the voltages of the three unit cell layers 15a, 15b, and 15c can be attached. Variations in ΔV1, ΔV2, and ΔV3 are reduced, and the voltages ΔV1, ΔV2, and ΔV3 of the three unit cell layers 15a, 15b, and 15c can be accurately measured.

According to the wiring substrates 21 of Reference Examples 1 , 2 , and 3 attached to the stack 2, the current collectors 4a, 4b, 4c, and 4d are resin current collectors using a conductive material as a polymer material. Since the resin current collector is more elastic than the metal current collector and can be more closely attached to the exposed conductive portions 121 to 124 of the terminal portions 22a, 23a, 24a, and 25a of the wiring board 21, the tensile stress accompanying vibration Can be relaxed to prevent the wiring substrate 21 from being disconnected.

FIGS. 10A to 10C are schematic model views of the wiring board 21 according to the first , second , and third embodiments of the present invention . The reference example 2 shown in FIG. The wiring board 21 is replaced. Among these, the wiring substrate 21 of the first embodiment shown in FIG. 10A has four tooth widths (thicknesses) on the premise of the wiring substrate 21 of Reference Example 2 shown in FIG. The fourth tooth, the third tooth, the second tooth, and the first tooth are widened in this order. That is, the width of the fourth tooth 21d is the same as the width (first reference width W1) of the fourth tooth 21d of the wiring board 21 of the reference example 2 shown in FIG. 8A, and the width of the third tooth 21c ′. Is wider than the first reference width W1, the width of the second tooth 21b ′ is wider than the width of the third tooth 21c ′, and the width of the first tooth 21a ′ is wider than the width of the second tooth 21b ′. . Tooth width is a substitute for tooth thickness. This is because the entire wiring board 21 is formed in a thin film shape, so that the width of the teeth is widened instead of thickening the teeth.

The wiring board 21 of the second embodiment shown in FIG. 10B is based on the wiring board 21 of Reference Example 2 shown in FIG. The fourth tooth, the third tooth, the second tooth, and the first tooth are enlarged in this order with the fourth tooth at the first reference height as a reference. That is, the exposed conductive portion area of the exposed conductive portion 124 of the fourth terminal portion 25a is the same as the exposed conductive portion area (first reference area S1) of the exposed conductive portion 124 of the fourth terminal portion 25a of the wiring board 21 of Reference Example 2. The exposed conductive portion area of the exposed conductive portion 123 ′ of the third terminal portion 24a ′ is larger than the exposed conductive portion area of the exposed conductive portion 124 of the fourth terminal portion 25a, and the exposed conductive portion 122 of the second terminal portion 23a ′. The exposed conductive portion area of 'is larger than the exposed conductive portion area of the exposed conductive portion 123' of the third terminal portion 24a ', and the exposed conductive portion area of the exposed conductive portion 121' of the first terminal portion 22a 'is set to the second terminal portion. It is larger than the exposed conductive part area of the exposed conductive part 122 'of 23a'.

A wiring board 21 according to the third embodiment shown in FIG. 10C includes the wiring board 21 according to the first embodiment shown in FIG. 10A and the wiring board 21 according to the second embodiment shown in FIG. Is a combination.

When the stack 2 having a large number of unit cell layers connected in series is used in an environment where vibration occurs, the widths (thicknesses) of the four teeth 21a, 21b, 21c, and 21d of the wiring board 21 are the same. Since the tensile stress acting on the exposed conductive portion of the terminal portion of the tooth increases with vibration as the tooth moves away from the tooth at the first reference height (first reference position), the wiring formed on the insulating substrate 26 Disconnections of 22, 23, 24, and 25 can occur. According to the wiring board 21 of the first and third embodiments, as shown in FIGS. 10 (a) and 10 (c), the teeth separated from the first reference height (first reference position) among the four teeth. In other words, the width (thickness) of the teeth is increased (thickened) in the order of the fourth tooth 21d, the third tooth 21c ′, the second tooth 21b ′, and the first tooth 21a ′. That is, by increasing (thickening) the width (thickness) of the teeth as the tensile stress increases, disconnection of the wirings 22, 23, 24, and 25 due to vibration can be prevented. In addition, as a case where the stack 2 is used in an environment where vibration occurs, a case where the stack 2 is mounted on an automobile can be considered.

According to the wiring board 21 of the second and third embodiments, as shown in FIGS. 10B and 10C, the teeth that are further away from the first reference height (first reference position) among the four teeth. That is, the exposed conductive portion area of the exposed conductive portion of the terminal portion and the adhesive area of the conductive tape at the tip of the teeth in the order of the fourth tooth 21d, the third tooth 21c ′, the second tooth 21b ′, and the first tooth 21a ′. It is getting bigger. That is, by increasing the adhesive force between the exposed conductive portion of the terminal portion and the current collector as the tooth with an increased tensile stress, the tensile stress associated with vibration can be reduced, and the wires 22, 23, 24, 25 are disconnected. Can be prevented.

FIGS. 32A and 32B show the wiring board 21 of the fourteenth embodiment in a simplified model diagram. Among these, the wiring board 21 of FIG. 32A shows the side where the exposed conductive parts 121 to 124 can be seen on the front side of the paper, and FIG. 32B shows the side where the exposed conductive parts 121 to 124 cannot be seen on the front side of the paper. Yes. The insulating part at the periphery of the terminal part is not shown. Then, as shown in FIG. 32A, conductive tapes 111 to 114 are placed on the front side of the exposed conductive portions 121 to 124 in the drawing. On the other hand, FIGS. 32C and 32D show the wiring board 21 of the fifteenth embodiment in a simplified model diagram. Among these, the wiring board 21 in FIG. 32C shows the side where the exposed conductive portions 121 to 124 can be seen in front of the paper, and FIG. 32D shows the side where the exposed conductive portions 121 to 124 cannot be seen in front of the paper. Yes. The insulating part at the periphery of the terminal part is not shown. And as shown in FIG.32 (c), the conductive tapes 111-114 are set | placed on the paper surface near side of the exposed conductive parts 121-124. In the reference examples 1 to 5 and the wiring boards 21 of the first to third embodiments described so far (also for the wiring boards 21 of the fourth to thirteenth embodiments described later), an insulating portion is provided on the periphery of the terminal portion. If the terminal area is increased, the exposed conductive area increases. However, the configuration of the terminal portion is not limited to this, and there is a configuration in which the exposed conductive portion area is not changed even if the terminal portion area is increased. In this case, all the exposed conductive parts formed in each terminal part have the same first reference area S1. The reason why the exposed conductive part areas are all set to the same first reference area S1 in addition to the terminal part area is to make the contact resistance between the exposed conductive part and the current collector equal in each terminal part.

As described above, when all the exposed conductive portion areas are set to the same first reference area S1 in addition to the terminal portion area, the wiring boards shown in FIGS. 32 (a), (b), (c), and (d). In the simplified model diagram of FIG. 21, since it is difficult to understand the relationship between the terminal area, the exposed conductive area, and the adhesive area of the conductive tape, schematic sectional views are shown in FIGS. 33A and 33B. That is, FIG. 33A is a schematic cross-sectional view showing a state where the exposed conductive portions 121 to 124 of the four terminal portions 22a ′, 23a ′, 24a ′, and 25a of the fourteenth embodiment are attached to the current collector. FIG. 33B is a schematic cross-sectional view showing a state in which the exposed conductive portions 121 to 124 of the four terminal portions 22a, 23a, 24a, and 25a according to the fifteenth embodiment are attached to the current collector.

In the wiring board 21 of the fourteenth embodiment shown in FIGS. 32A, 32B, and 33A, the exposed conductive portion areas of the exposed conductive portions 121 to 124 are all set to the same first reference area S1 in each terminal portion. As a premise, the adhesive area of the four conductive tapes 111 to 114 is increased in the order of the fourth conductive tape 114, the third conductive tape 113, the second conductive tape 112, and the first conductive tape 111. It is. However, the terminal area is increased in the order of the fourth terminal section 25a, the third terminal section 24a ′, the second terminal section 23a ′, and the first terminal section 22a ′. The configuration other than the four terminal portions and the four conductive tapes is the same as that of the wiring substrate 21 of the second embodiment shown in FIG.

The wiring board 21 according to the fifteenth embodiment shown in FIGS. 32C, 32D, and 33B is based on the assumption that the terminal portions of the four terminal portions 22a, 23a, 24a, and 25a have the same area S3. The adhesion area of the four conductive tapes 111, 112, 113, 114 was increased in the order of the fourth conductive tape 114, the third conductive tape 113, the second conductive tape 112, and the first conductive tape 111. Is. The configuration other than the four terminal portions and the four conductive tapes is the same as that of the wiring substrate 21 of the second embodiment shown in FIG.

Next, FIG. 11 is a schematic longitudinal sectional view of the bipolar secondary battery 30 to which the wiring boards 41 to 45 of the fourth embodiment are attached, and FIG. 12 is a bipolar to which the wiring boards 41 to 45 of the fourth embodiment are attached. It is the top view which looked at the part except a part of high electric power tabs 16 and 17 from the type | mold secondary battery 30 from the top. In FIG. 11, it is assumed that the upper side is vertically upward and the lower side is vertically downward.

The bipolar secondary battery 30 to which the wiring boards 41 to 45 of the fourth embodiment are attached is a bipolar secondary battery configured by connecting five (plural) stacks 2 shown in FIGS. 1 to 3 in series. It is a battery. Here, in order to distinguish the five stacks 2, the first stack 31, the second stack 32, the third stack 33, the fourth stack 34, and the fifth stack 35 are shown in FIG. . Further, in order to distinguish the five wiring boards 21 attached to the five stacks 31 to 35, the first wiring board 41, the second wiring board 42, and the third wiring board in FIG. 43, a fourth wiring board 44, and a fifth wiring board 45.

  The bipolar secondary battery shown in FIG. 11 is actually as shown in FIG. Here, FIG. 13 shows a partially enlarged vertical sectional view in a state where the first, second, and third stacks 31, 32, and 33 are stacked (connected in series), and the fourth, fifth 2 The stacked portions of the two stacks 34 and 35 are not shown.

  As illustrated in FIG. 13, when the second stack 32 is stacked on the first stack 31, the uppermost current collector (fourth current collector 4 d) of the first stack 31 and the second stack 32. Align the horizontal position with the lowermost current collector (first current collector 4 a) of the two current collectors, and seal the same sealing material 11 as used for the manufacture of the stacks 31, 32 on the peripheral edges of the two current collectors in the horizontal direction. As a result, the positive electrode active material layer 5 and the negative electrode active material layer 6 are insulated from each other, and a predetermined space is formed between the positive electrode active material layer 5 and the negative electrode active material layer 6 facing in the vertical direction. Then, the electrolyte layer 7 is formed by filling the space with a liquid or gel electrolyte. A separator (12) is provided inside the electrolyte layer 7 to prevent the two active material layers (5, 6) facing each other from being in electrical contact.

  Next, when the third stack 33 is stacked on the second stack 32, the same method as the method of stacking the second stack 32 on the first stack 31 is used. Although not shown, when the fourth stack 34 is stacked on the third stack 33 and when the fifth stack 35 is stacked on the fourth stack 34, the second stack 32 is formed on the first stack 31. The same method as the stacked method is used. In this way, the stacking of the five stacks 31 to 35 is completed. Next, the high voltage tab 16 is electrically connected to the negative electrode active material layer 6 at the uppermost end of the fifth stack 35, and the high voltage tab 17 is electrically connected to the positive electrode active material layer 5 at the lowermost end of the first stack 31.

  The stacking method of the plurality of stacks is not limited to the method shown in FIG. For example, as shown in FIG. 34, the stack 2 shown in FIG. 3 may be laminated as it is. In FIG. 34 and FIG. 13, it goes without saying that the exposed conductive portions of the four terminal portions and the four current collectors are bonded to each wiring board using a conductive tape.

  As shown in FIG. 11, the upper and lower ends are sandwiched between high-voltage tabs 16, 17, and the whole including the two high-voltage tabs 16, 17 is covered with a laminate film (not shown) and sealed with a seal portion 53. The high power tabs 16 and 17 are actually as shown in FIG. Here, FIG. 35 is a perspective view showing only two high-power tabs 16 and 17. The two high electric tabs 16 and 17 are formed of a flat plate-like conductive member in a rectangular shape and have protrusions 16a and 17a at one corner. These protrusions 16 a and 17 a penetrate the exterior material of the bipolar secondary battery 30 and go out.

  When the bipolar secondary battery 30 is configured by stacking the five stacks 31 to 35 in this way (connected in series), one wiring board is required for each stack. In total, 30 wiring boards 41 to 45 are required. The five wiring boards 41 to 45 need to be entirely covered with a laminate film as shown in FIG. 11 and sealed with a seal portion 54 at a certain height in the vertical direction. Here, the height of the stack at the position where the five wiring boards 41 to 45 are sealed is referred to as a “second reference height” (second reference position). Here, in FIG. 11, five wiring boards 41, 42, 43, 44, 45 attached to the bipolar secondary battery 30 are attached to the first wiring board 41, the second wiring board 42, the third wiring board 43, the fourth wiring board from the bottom. The wiring board 44 and the fifth wiring board 45 are distinguished.

  FIG. 14 is a plan view of the wiring boards 41 to 45 of Comparative Example 2 attached to the bipolar secondary battery 30. 14 shows a plan view of the fifth wiring board 45 attached to the fifth stack 35. 14 is a plan view of the fourth wiring board 44 attached to the fourth stack 34 in the second stage, and is attached to the third stack 33 (stack at the second reference height) in the third stage of FIG. A plan view of the third wiring board 43, a plan view of the second wiring board 42 attached to the second stack 32 in the fourth stage of FIG. 14, and a first wiring board attached to the first stack 31 in the lowermost stage of FIG. A plan view of 41 is shown on the same scale as the fifth wiring board 45.

As for the wiring boards 41-45 of the comparative example 2 shown in FIG. 14, all the five wiring boards 41-45 are the same dimensions and the same shape as the wiring board 21 of the reference example 2 shown to Fig.8 (a). . That is, the width of the handle 21g of the third wiring board 43 is set to the second reference width W2, the length of the handle 21g of the third wiring board 43 is set to the third reference length L3, and the fourth terminal portion 25a of the third wiring board 43 is set. The exposed conductive part area of the exposed conductive part 124 is defined as a first reference area S1. At this time, the widths of the patterns 21g of the first, second, fourth, and fifth wiring boards 41, 42, 44, and 45 are all set to the second reference width W2 that is the same as the width of the pattern 21g of the third wiring board 43. The lengths of the patterns 21g of the first, second, fourth, and fifth wiring boards 41, 42, 44, and 45 are all set to the third reference length L3 that is the same as the length of the pattern 21g of the third wiring board 43. The exposed conductive portion areas of the exposed conductive portions 124 to 121 of the first, second, fourth, and fifth wiring substrates 41, 42, 44, and 45 are the terminals of the third wiring substrate 43. It is the same as the first reference area S1 that is the exposed conductive portion area of the exposed conductive portions 124 to 121 of the portions 25a, 24a, 23a, and 22a.

  Here, since the thickness of the pattern is also a concept including the width and thickness of the pattern, the width and thickness of the pattern are individually defined. The width of the handle refers to the vertical width of the handle 21g in FIG. In FIG. 14, the handle 21g has a thickness in a direction penetrating the paper surface. The thickness of the handle means the thickness of the handle 21g in the direction penetrating the paper surface. If the thickness of the handle is the same, the handle can be thickened by increasing the width of the handle. If the width of the pattern is the same, the pattern can be thickened by increasing the thickness of the pattern.

  Now, in the wiring boards 41 to 45 of the comparative example 2, the thickness and length of the handle 21g and the exposed conductive part area of the terminal part are all the same between the wiring boards. If it is attached to the bipolar secondary battery 30, the second reference is attached to the wiring boards (that is, the first and fifth wiring boards 41, 45) attached to the stacks 31, 35 farthest from the second reference height. A larger tensile stress acts on the wiring board (that is, the third wiring board 43) attached to the stacks 31 and 35 at the height. Due to the large tensile stress, the exposed conductive portions of the terminal portions of the first and fifth wiring boards 41 and 45 attached to the stack farthest from the second reference height easily peel off from the current collector, resulting in poor contact. Or there is a possibility of disconnection.

Therefore, as the wiring boards 41 to 45 of the fourth embodiment, as shown in FIG. 11, the wiring board attached to the stack away from the second reference height is made longer.

The wiring boards 41 to 45 of the fourth embodiment will be specifically described with reference to FIG. FIG. 15 is a plan view of the wiring boards 41 to 45 of the fourth embodiment. In the upper part of FIG. 15, a plan view of the third wiring board 43 attached to the third stack 33 (stack at the second reference height) is shown. 15 is a plan view of the second and fourth wiring boards 42 and 44 attached to the second and fourth stacks 32 and 34, and the lower part of FIG. A plan view of the first and fifth wiring boards 41 and 45 attached to the two stacks 31 and 35 is shown on the same scale as the third wiring board 43.

  Here, the length of the third wiring board 43 attached to the stack 33 at the second reference height is defined as a second reference length L2. At this time, the lengths of the second and fourth wiring boards 42 and 44 are longer than the second reference length L2, and the lengths of the first and fifth two wiring boards 41 and 45 are the second and fourth lengths. The two wiring boards 42 and 44 are made longer than the length. In this case, the comb-shaped portion 21f including the four teeth 21a, 21b, 21c, 21d and the trunk 21e of each wiring board 41 to 45 is not changed between the wiring boards 41 to 45, and each wiring board 41 to 45 is not changed. This is dealt with by changing the length of the 45 handles 21g. That is, when the length of the handle 21g of the third wiring board 43 is the third reference length L3, and the width (thickness) of the handle 21g of the third wiring board 43 is the second reference width W2, it is shown in FIG. As described above, the length of the handle 21g ′ of the second and fourth wiring boards 42 and 44 is made longer than the third reference length L3 by a predetermined value ΔL2, and the first and fifth wiring boards 41, The length of the 45 handle 21g ″ is made longer by a predetermined value ΔL2 than the length of the handle 21g ′ of the second and fourth wiring boards 42 and 44. The widths of the handles 21g 'and 21g "of the first, second, fourth, and fifth wiring boards 41, 42, 44, and 45 are the same as the second reference width W2. Note that the wiring boards 41 to 45 of the comparative example 2 shown in FIG. 14 have the length of the handle 21g of the first, second, fourth, and fifth wiring boards 41, 42, 44, and 45 all the third wiring. The third reference length L3 is the same as the length of the pattern 21g of the substrate 43, and the widths of the patterns 21g of the first, second, fourth, and fifth wiring substrates 41, 42, 44, and 45 are all third wiring substrates. The second reference width W2 is the same as the width of the 43 handle 21g.

The method of attaching the five wiring boards 41 to 45 configured in this way to the corresponding stacks 31 to 35 is the same as the method of attaching the wiring board 21 of Reference Example 1 to the stack 21. However, after the five wiring boards 41 to 45 are attached to the corresponding stacks 31 to 35, the five wiring boards 41 to 45 are sealed by the seal portion 54 as shown in FIG.

When the bipolar secondary battery 30 having a large number of five stacks connected in series is used in an environment in which vibration occurs, the third reference length L3 having the same length of the handle 21g of the five wiring boards 41 to 45 is used. In order to bundle the wiring boards 41 to 45 of the comparative example 2, the tensile stress acting on the handle 21g due to vibration is as much as the handle 21g of the wiring board attached to the stack that is separated from the second reference height (second reference position). Therefore, the wirings 22, 23, 24, 25 formed on the insulating substrate 26 may be disconnected. On the other hand, according to the wiring boards 41 to 45 of the fourth embodiment, as shown in FIG. 15, from a predetermined second reference height (second reference position) among the five wiring boards 41 to 45. The longer the wiring board is, that is, the third wiring board 43, the second and fourth wiring boards 42 and 44, and the first and fifth two wiring boards 41 and 45 are increased in length in this order. doing. That is, according to the wiring boards 41 to 45 of the fourth embodiment, the length of the handle is increased as the tensile stress acting on the wiring board increases, so that it is attached to the stack at a position away from the second reference height. Disconnection that occurs in the wirings 22, 23, 24, and 25 of the wiring board can be prevented. In addition, as a case where the bipolar secondary battery 30 is used in an environment where vibration occurs, a case where the bipolar secondary battery 30 is mounted on an automobile can be considered.

According to the wiring boards 41 to 45 of the fourth embodiment attached to the bipolar secondary battery 30, the current collectors 4 a, 4 b, 4 c, and 4 d of the five wiring boards 41 to 45 are each made of a polymer material with a conductive member. The resin current collector used is used. Since the resin current collector is more elastic than the metal current collector and can be more closely attached to the exposed conductive portions 121 to 124 of the terminal portions 22a, 23a, 24a, and 25a of the wiring board 21, the tensile stress accompanying vibration Can be relaxed and disconnection of each of the five wiring boards 41 to 45 can be prevented.

FIG. 16 is a plan view of the wiring boards 41 to 45 of the fifth embodiment attached to the bipolar secondary battery 30 and replaces the wiring boards 41 to 45 of the fourth embodiment shown in FIG.

The wiring boards 41 to 45 of the fifth embodiment, on the premise of the wiring boards 41 to 45 of the fourth embodiment, further expose the exposed conductive portion of the terminal portion of the wiring board as the wiring board is attached to the stack that is further away from the second reference height. The area of the conductive part is increased. That is, in the wiring substrates 41 to 45 of the fourth embodiment shown in FIG. 15, the exposed conductive portions 121 to 124 of the four terminal portions 22a, 23a, 24a, and 25a are exposed to the five wiring substrates 41 to 45. The partial area was the first reference area S1. In contrast, in the wiring boards 41 to 45 of the fifth embodiment shown in FIG. 16, the four terminal portions 22a-1, 23a-1, and 24a-1 of the second and fourth wiring boards 42 and 44 are provided. , 25 a-1, the exposed conductive part area of the exposed conductive parts 121-1, 122-1, 123-1, and 124-1 is a terminal part area S 1 ′ larger than the first reference area S 1, Exposed conductive part area of the exposed conductive parts 121-2, 122-2, 123-2, 124-2 of the four terminal parts 22a-2, 23a-2, 24a-2, 25a-2 of the wiring boards 41, 45 Is a terminal area S1 ″ larger than the exposed conductive area S1 ′ of the exposed conductive parts 121-1, 122-1, 123-1, and 124-1 of the second and fourth wiring boards 42 and 44.

Next, FIG. 17 is a schematic longitudinal sectional view of the bipolar secondary battery 30 to which the wiring boards 61 to 65 of the sixth embodiment are attached, and FIG. 18 is a bipolar to which the wiring boards 61 to 65 of the sixth embodiment are attached. FIG. 19 is a plan view of the wiring board 61 to 65 according to the sixth embodiment, and FIG. 19 is a plan view of a portion obtained by removing a part of the high voltage tabs 16 and 17 from the type secondary battery 30. This replaces FIG. Also in FIG. 17, it is assumed that the upper part is vertically upward and the lower part is vertically downward.

The wiring boards 61 to 65 according to the sixth embodiment shown in FIG. 19 are based on the wiring boards 41 to 45 according to the fourth embodiment shown in FIG. 15 and are designed to be attached to the stack further away from the second reference height. The width (thickness) of the pattern of the wiring board is increased. That is, as shown in FIG. 19, the length of the handle 21g of the third wiring board 63 is the third reference length L3, and the width (thickness) of the handle 21g of the third wiring board 63 is the second reference width W2. Then, the length of the handle 21g ′ of the second and fourth wiring boards 62 and 64 is made longer than the third reference length L3 by a predetermined value ΔL2, and the second and fourth two wiring boards 62, The width of the handle 21g ′ of 64 is set to a width W2 ′ wider than the second reference width W2, and the length of the handle 21g ″ of the first and fifth wiring boards 61 and 65 is set to the second and fourth 2s. The length of the handle 21g ′ of the first and fifth wiring boards 61 and 64 is made longer than the length of the handle 21g ′ of the two wiring boards 62 and 64 by a predetermined value ΔL2, and the width of the second and fourth two The width W2 ″ is wider than the width W2 ′ of the wiring boards 62 and 64.

When the bipolar secondary battery 30 having a large number of five stacks connected in series is used in an environment in which vibrations occur, the second reference has the same width (thickness) of the handle 21g of the five wiring boards 61 to 65. When the width is W2, the pattern of the wiring board attached to the stack that is farther from the second reference height (second reference position) is formed on the insulating substrate 26 because the tensile stress acting on the pattern increases with vibration. Disconnection may occur in the wirings 22, 23, 24, and 25. On the other hand, according to the wiring boards 61 to 65 of the sixth embodiment, a predetermined second reference height (second reference position) among the five wiring boards 61 to 65 as shown in FIG. As the wiring boards are further away, that is, the third wiring board 63, the second and fourth wiring boards 62 and 64, and the first and fifth two wiring boards 61 and 65 in this order (thickness of the wiring board). Is wide (thick). That is, according to the wiring boards 61 to 65 of the sixth embodiment, the width (thickness) of the handle is widened (thickened) as the tensile stress acting on the wiring board increases, thereby moving away from the second reference height. It is possible to prevent disconnection that occurs in the wirings 22, 23, 24, and 25 of the wiring board attached to the stack at the position.

FIG. 20 is a plan view of the bipolar secondary battery 30 to which the wiring boards 61 to 65 of the seventh embodiment are attached, which replaces the wiring boards 61 to 65 of the sixth embodiment shown in FIG.

The wiring boards 61 to 65 of the seventh embodiment are based on the wiring boards 61 to 65 of the sixth embodiment shown in FIG. 19, and the wiring boards attached to the stack further away from the second reference height are closer to the terminal portions of the wiring board. The exposed conductive part area of the exposed conductive part is increased. That is, in the wiring boards 61 to 65 of the sixth embodiment shown in FIG. 19, the exposed conductive parts 121 to 124 of the four terminal parts 22a, 23a, 24a, and 25a are exposed to the five wiring boards 61 to 65. The partial area was the first reference area S1. On the other hand, in the wiring substrates 61 to 65 of the seventh embodiment shown in FIG. 20, the exposed conductive portion areas of the exposed conductive portions 121 to 124 of the four terminal portions 22a, 23a, 24a, and 25a of the third wiring substrate 63 are the first. The exposed conductive parts 121-3, 122- of the four terminal portions 22a-3, 23a-3, 24a-3, 25a-3 of the second and fourth wiring boards 62, 64 are the same as the reference area S1. The exposed conductive portion areas of 3, 123-3 and 124-3 are set to a terminal portion area S1 ′ larger than the first reference area S1, and the four terminal portions 22a-4 of the first and fifth two wiring boards 61 and 65 are used. , 23a-4, 24a-4, 25a-4 exposed conductive portions 121-4, 122-4, 123-4, 124-4, the exposed conductive portion area is the second and fourth wiring boards 62, 64. Exposed conductive portions 121-3, 122-3, 123-3, 12 The terminal area S1 ″ is larger than the exposed conductive area S1 ′ of 4-3.

When the bipolar secondary battery 30 having a large number of five stacks connected in series is used in an environment in which vibration is generated, the exposed conductive portions of the terminal portions at the tips of the teeth of the five wiring boards 61 to 65 are exposed. When the conductive portion area has the same first reference area S1, the terminal portion of the wiring board that is attached to the stack that is separated from the second reference height (second reference position) is accompanied by vibration in the exposed conductive portion of the terminal portion of the wiring board. Therefore, even if the wirings 22, 23, 24, and 25 are not disconnected, the exposed conductive portion of the terminal portion may be disconnected. On the other hand, according to the wiring boards 61 to 65 of the seventh embodiment, as shown in FIG. 20, from the predetermined second reference height (second reference position) among the five wiring boards 61 to 65. Terminals that are provided at the tips of the wiring board teeth in the order of the third wiring board 63, the second and fourth wiring boards 62 and 64, and the first and fifth two wiring boards 61 and 65, as the wiring boards are farther away. The exposed conductive part area of the exposed conductive part is increased. That is, according to the wiring boards 61 to 65 of the seventh embodiment, the second reference height is increased by increasing the exposed conductive part area of the exposed conductive part of the terminal part of the wiring board as the tensile stress acting on the wiring board increases. It is possible to prevent disconnection that occurs at the terminal portion of the wiring board that is attached to the stack at a position far from the above.

FIG. 36 is a plan view of the bipolar secondary battery 30 to which the wiring boards 61 to 65 of the sixteenth embodiment are attached, and replaces the wiring boards 61 to 65 of the seventh embodiment shown in FIG.

In the wiring boards 61 to 65 of the sixteenth embodiment, on the premise of the wiring boards 61 to 65 of the seventh embodiment shown in FIG. 20, the wiring board attached to the stack further away from the second reference height is exposed to the terminal portion. The exposed conductive part area of the conductive part is increased and the tooth width is widened, and the tooth away from the first reference height for each wiring board increases the exposed conductive part area of the exposed conductive part of the terminal part and the tooth width. Is to widen. That is, in the wiring boards 61 to 65 of the sixteenth embodiment shown in FIG. 36, the exposed conductive part area of the exposed conductive part 124 of the fourth terminal part 25a in the third wiring board 63 is the first reference area S1, and the third terminal The exposed conductive portion area of the exposed conductive portion 123 ′ of the portion 24a ′ is larger than the first reference area S1, and the exposed conductive portion area of the exposed conductive portion 122 ′ of the second terminal portion 23a ′ is the exposed conductive portion of the third terminal portion 24a ′. The exposed conductive portion area of the first terminal portion 22a ′ is larger than the exposed conductive portion area of the exposed conductive portion 122 ′ of the second terminal portion 23a ′. Yes. Further, regarding the third wiring board 63, the width of the teeth of the fourth teeth 21d is the first reference width W1, the width of the teeth of the third teeth 21c ′ is wider than the width W1 of the teeth of the fourth teeth 21d, and the second The width of the tooth 21b ′ is wider than the width of the third tooth 21c ′, and the width of the first tooth 21a ′ is wider than the width of the second tooth 21b ′.

  For the second and fourth wiring boards 62 and 64, the exposed conductive part area of the exposed conductive part 124-3 of the fourth terminal part 25 a-3 is the exposed conductive part 124 of the fourth terminal part of the third wiring board 63. The exposed conductive portion area of the exposed conductive portion 124-3 of the fourth terminal portion 25a-3 is defined as an exposed conductive portion area of the exposed conductive portion 123-3 of the third terminal portion 24a-5. The exposed conductive portion area of the exposed conductive portion 122-5 of the second terminal portion 23a-5 is larger than the exposed conductive portion area of the exposed conductive portion 123-5 of the third terminal portion 24a-5. The exposed conductive portion area of the exposed conductive portion 121-5 of the first terminal portion 22a-5 is larger than the exposed conductive portion area of the exposed conductive portion 122-5 of the second terminal portion 23a-5.

  Further, the tooth width of the fourth tooth 21d ′ for the second and fourth wiring boards 62 and 64 is set to be a width W1 ′ wider than the tooth width W1 of the fourth terminal portion of the third wiring board 63, and the third tooth The width of the teeth of 21c ″ is wider than the width of the teeth W1 ′ of the fourth teeth 21d ′, the width of the teeth of the second teeth 21b ″ is wider than the width of the teeth of the third teeth 21c ″; The width of the first tooth 21a '' is wider than the width of the second tooth 21b ''.

  The exposed conductive portion area of the exposed conductive portion 124-4 of the fourth terminal portion 25a-4 for the first and fifth wiring substrates 61 and 65 is the same as that of the fourth terminal portion for the second and fourth wiring substrates 62 and 64. The exposed conductive portion area S1 ′ is larger than the exposed conductive portion area S1 ′ of the exposed conductive portion 124-3, and the exposed conductive portion area of the exposed conductive portion 123-6 of the third terminal portion 24a-6 is exposed to the fourth terminal portion 25a-4. The exposed conductive part area S1 ″ of the conductive part 124-4 is larger than the exposed conductive part area S1 ″, and the exposed conductive part area of the exposed conductive part 122-6 of the second terminal part 23a-6 is the exposed conductive part 123 of the third terminal part 24a-6. The exposed conductive part area of the first terminal part 22a-6 is set to be larger than the exposed conductive part area of the first terminal part 22a-6, and the exposed conductive part area of the exposed conductive part 122-6 of the second terminal part 23a-6 The area is larger than the area.

  Further, the tooth width of the fourth tooth 21d ″ for the first and fifth wiring boards 61 and 65 is wider than the tooth width W1 ′ of the fourth terminal portion for the second and fourth wiring boards 62 and 64. The width of the third tooth 21c ′ ″ is wider than the width W1 ″ of the fourth tooth 21d ″, and the width of the second tooth 21b ′ ″ is the width of the third tooth 21c ′ ″. The width of the first tooth 21a ′ ″ is wider than the width of the second tooth 21b ′ ″.

21 is a schematic longitudinal sectional view of the bipolar secondary battery 30 to which the wiring boards 71 to 75 of the eighth embodiment are attached, and FIG. 22 is a bipolar secondary to which the wiring boards 71 to 75 of the eighth embodiment are attached. FIG. 23 is a plan view of the battery 30 excluding a part of the high voltage tabs 16 and 17 as seen from above, and FIG. 23 is a plan view of five wiring boards of the eighth embodiment, which replaces FIG. 11, FIG. 12, and FIG. Is. Also in FIG. 21, it is assumed that the upper part is vertically upward and the lower part is vertically downward.

In the bipolar secondary battery 30 shown in FIG. 21, a certain height of the fifth stack 35 is set as a second reference height. The wiring boards 71 to 75 of the eighth embodiment will be described with reference to FIG. 23. A plan view of the fifth wiring board 75 attached to the fifth stack 35 (stack at the second reference height) at the top of FIG. Show. 23, the fourth, third, second, and first stacks 34, 33, 32, and 31 are attached to the second, third, fourth, and fifth stages. The plan views of the third, second and first wiring boards 74, 73, 72 and 71 are shown on the same scale as the fifth wiring board 75.

  Here, the length of the fifth wiring board 75 attached to the stack at the second reference height (that is, the fifth stack 35) is defined as a second reference length L2. At this time, the length of the fourth wiring board 74 is made longer than the second reference length L2, the length of the third wiring board 73 is made longer than the length of the fourth wiring board 74, and the second wiring board 72 The length is longer than the length of the third wiring board 73, and the length of the first wiring board 71 is longer than the length of the second wiring board 72. In this case, the comb-shaped portion 21f including the four teeth 21a, 21b, 21c, 21d and the trunk 21e of each wiring board 71 to 75 is not changed between the wiring boards 71 to 75, and each wiring board 71 to 75 is not changed. This is dealt with by changing the length of the 75 handle 21g and the width (thickness) of the handle 21g. That is, when the length of the handle 21g of the fifth wiring board 75 is the third reference length L3 and the width (thickness) of the handle 21g of the fifth wiring board 75 is the second reference width W2, it is shown in FIG. As described above, the length of the handle 21g ′ of the fourth wiring board 74 is longer than the third reference length L3 by a predetermined value ΔL3, and the width of the handle 21g ′ of the fourth wiring board 74 is wider than the second reference width W2. The length of the handle 21g '' of the third wiring board 73 is made longer than the length of the handle 21g 'of the fourth wiring board 74 by a predetermined value ΔL3, and the handle 21g' 'of the third wiring board 74 is set to the width W2'. The width W2 ″ is wider than the width of the handle 21g ′ of the fourth wiring board 72, and the length of the handle 21g ′ ″ of the second wiring board 72 is the length of the handle 21g ″ of the third wiring board 73. The width of the handle 21g ′ ″ of the second wiring substrate 72 is longer than the length by a predetermined value ΔL3 and the third wiring. The width W2 ′ ″ is wider than the width of the handle 21g ″ of the board 73, and the length of the handle 21g ″ ″ of the first wiring board 71 is longer than the length of the handle 21g ′ ″ of the second wiring board 72. Further, the width W2 ″ ″ is longer by a predetermined value ΔL3 and the width of the handle 21g ″ ″ of the first wiring board 71 is wider than the width of the handle 21g ′ ″ of the second wiring board 72.

The effects of the wiring boards 71 to 75 of the eighth embodiment shown in FIGS. 21 and 23 are the same as the effects of the wiring board of the sixth embodiment shown in FIGS. 17 and 19.

Next, the upper part of FIG. 24 is a schematic longitudinal sectional view showing a connection state with the outside of the bipolar secondary battery 30 to which the wiring boards 41 to 45 of the fourth embodiment shown in FIGS. 11 and 15 are attached. . The lower part of FIG. 24 is a schematic view of the bipolar secondary battery 30 to which the wiring boards 41 to 45 of the fourth embodiment are attached, including a connection portion with the outside. In FIG. 24, the same parts as those in FIG.

As shown in the upper part of FIG. 24, the five stacks 31 to 35 constituting the bipolar secondary battery 30, the two high-voltage tabs 16 and 17, and the wiring boards 41 to 45 of the fourth embodiment are entirely laminated film 81. It is covered with (exterior material), and the inside is vacuumed and sealed by the seal portions 53 and 54. In addition to the laminate film 81, the high-power tabs 16 and 17 and the patterns of the five wiring boards 41 to 45, that is, the patterns 21g of the third wiring board 43, the patterns of the second and fourth wiring boards 42 and 44, are provided. 21g ′ and the handle 21g ″ of the first and fifth wiring boards 41 and 45 are provided. A connector (not shown) is provided at the ends of these five handles 21g, 21g ′, 21g ″, and is connected to a control circuit 82 including a monitor circuit, a balance control circuit, and the like via this connector.

  Here, the monitor circuit uses the voltage obtained via the second current collector 4b during charging of the bipolar secondary battery 30 and the voltage obtained via the first current collector 4a to determine the first cell layer 15a. The voltage ΔV1 of the second single battery layer 15b is obtained from the voltage obtained via the third current collector 4c and the voltage obtained via the second current collector 4b, and the fourth current collector 4d. The voltage ΔV3 of the third cell layer 15c is measured and output for each of the five stacks 31 to 35 from the voltage obtained via the third current collector 4c and the voltage obtained via the third current collector 4c.

  In the balance control circuit that receives three voltages ΔV1, ΔV2, and ΔV3 for each of the five stacks 31 to 35 from the monitor circuit, the three voltages ΔV1, ΔV2, and ΔV3 are the same for each of the five stacks 31 to 35. Thus, feedback control is performed on the charging current flowing through the three single cell layers 15a, 15b, and 15c for each of the five stacks 31 to 35.

Each of the upper stages of FIGS. 25, 26, and 27 is a schematic longitudinal section showing a connection state with the outside of the bipolar secondary battery 30 to which the wiring boards 91 to 95 of the ninth , tenth , and eleventh embodiments are attached. In each of the bottom views of FIG. 25, FIG. 26, and FIG. 27, the bipolar secondary battery 30 to which the wiring boards 91 to 95 of the ninth , tenth , and eleventh embodiments including the connection portion with the outside are attached is provided. FIG. The wiring boards 91 to 95 according to the ninth , tenth , and eleventh embodiments satisfy various requirements when the bipolar secondary battery 30 to which the five wiring boards 91 to 95 are attached is mounted on the vehicle. Is for.

The wiring boards 91 to 95 of the ninth embodiment shown in the upper part of FIG. 25 are modifications of the wiring boards 71 to 75 of the eighth embodiment shown in FIG. That is, the second reference height is set further vertically above the case of the wiring boards 71 to 75 of the eighth embodiment shown in FIG.

In the upper part of FIG. 25, in addition to the bipolar secondary battery 30 and the wiring boards 91 to 95 of the ninth embodiment, a control circuit 82 including a monitor circuit and a balance control circuit is also covered with a laminate film 81 and the inside is sealed on the left and right sides. The parts 53 and 54 are evacuated and sealed. In the lower part of FIG. 25, the control circuit 82 appears to be outside the laminate film 81, but the control circuit 82 is actually covered with the laminate film 81.

The wiring boards 91 to 95 of the tenth embodiment shown in the upper part of FIG. 26 are wirings 101 for notifying abnormalities such as a lower limit voltage and an upper limit voltage on the premise of the wiring boards 91 to 95 of the ninth embodiment shown in the upper part of FIG. The wiring 101 is led out from the left seal portion 53. On the other hand, the wiring boards 91 to 95 according to the eleventh embodiment shown in the upper part of FIG. 27 are wirings 102 for notifying abnormality such as a lower limit voltage and an upper limit voltage on the premise of the wiring boards 91 to 95 of the ninth embodiment shown in the upper part of FIG. The wiring 102 is led out from the right seal part 54.

  Here, the voltage from the four current collectors 4 a, 4 b, 4 c, and 4 d is supplied to the control circuit 82 via the five wiring boards 91 to 95 for each of the five stacks 31 to 35 constituting the bipolar secondary battery 30. The monitor circuit in the control circuit 82 measures the voltages ΔV1, ΔV2, and ΔV3 of the three cell layers 15a, 15b, and 15c for each of the five stacks 31 to 35. These three voltages ΔV1, ΔV2, and ΔV3 are within an allowable range if there is no abnormality in battery performance in the three unit cell layers 15a, 15b, and 15c. Actually, abnormalities in battery performance may occur in each of the three unit cell layers 15a, 15b, and 15c. Therefore, it is convenient if an abnormality in battery performance occurring in each of the three unit cell layers 15a, 15b, and 15c can be diagnosed. Therefore, if an upper limit voltage Vuplmt and a lower limit voltage Vdownlmt are determined in advance for each of the three voltages ΔV1, ΔV2, and ΔV3, does any one of the three voltages ΔV1, ΔV2, and ΔV3 exceed the upper limit voltage Vuplmt? Alternatively, when the voltage is lower than the lower limit voltage Vdownlmt, it becomes possible to diagnose that any one of the three single cell layers 15a, 15b, and 15c has an abnormality in battery performance. That is, if a circuit for comparing the voltages ΔV1, ΔV2, and ΔV3 of the three unit cell layers 15a, 15b, and 15c with the upper limit voltage Vuplmt and the lower limit voltage Vdownlmt is additionally provided in the control circuit 82, the three unit cells are provided. It is possible to diagnose whether or not the battery layers 15a, 15b, and 15c have an abnormality in battery performance. This diagnosis result is output from the control circuit 82 to the outside via the wirings 101 and 102.

The upper part of FIG. 28 is a schematic longitudinal sectional view showing a connection state with the outside of the bipolar secondary battery 30 to which the wiring boards 41 to 45 of the twelfth embodiment are attached, and the lower part of FIG. 28 includes a connection part with the outside. It is a general-view figure of the bipolar secondary battery 30 with which the wiring board of 12th Embodiment was attached. FIG. 29 is a schematic view of a bipolar secondary battery 30 to which the wiring board of the thirteenth embodiment including a connection portion with the outside is attached.

The bipolar battery 30 to which the wiring boards 41 to 45 of the twelfth embodiment shown in FIG. 28 are attached is a modification of the bipolar battery 30 to which the wiring boards 41 to 45 of the fourth embodiment shown in FIG. It is an example. That is, in the bipolar battery 30 to which the wiring boards 41 to 45 of the fourth embodiment shown in FIG. 24 are attached, the high voltage tabs 16 and 17 are moved from the left seal part 53 to the outside and the five wiring boards 41 to 45 are arranged. The handles 21g, 21g ′, 21g ″ are exposed to the outside from the right seal portion 54. On the other hand, in the bipolar battery 30 to which the wiring boards 41 to 45 of the twelfth embodiment shown in FIG. 28 are attached, in addition to the handles 21g, 21g ′ and 21g ″ of the five wiring boards 41 to 45. The high-power tabs 16 and 17 are also exposed to the outside from the right seal portion 54. Therefore, there is nothing left outside from the left seal portion 53.

  In this case, the takeout positions of the two high power tabs 16 and 17 from the right seal portion 54 may be arranged outside the five handles 21g, 21g ′, and 21g ″ as shown in the lower part of FIG. However, as shown in FIG. 29, the two high-power tabs 16 and 17 may be taken out side by side on one side of the five handles 21g, 21g ′ and 21g ″.

  As shown in Table 1, Comparative Example 1 and six examples (Examples 1 to 6) were used for the wiring board attached to the stack, and Comparative Examples 2 and 5 were used for the wiring board attached to the bipolar secondary battery. Examples (Examples 7 to 11) were prepared.

  Here, in Comparative Example 1 and Examples 1 to 6, one wiring board is attached to one stack, but the specifications of the attached stack are common to Comparative Example 1 and Examples 1 to 6. Similarly, in Comparative Example 2 and Examples 7 to 10, five wiring boards are attached to one bipolar secondary battery, but the specifications of the attached bipolar secondary battery are common to Comparative Example 2 and Examples 7 to 11. It is. Therefore, a method for manufacturing these one stack and one bipolar secondary battery will be described first.

<Production of bipolar electrode>
Cut a conductive polymer film with a thickness of 50 μm using carbon fine particles as a conductive filler (volume low efficiency in the thickness direction: 1 × 10 ^ −1 Ω · cm) into a member having a predetermined length and width. Thus, a current collector was formed.

  Spinel LiMnO4 is used as the positive electrode active material, acetylene black is used as the conductive auxiliary agent, and polyvinylidene fluoride VDF is used as the binder, and the positive electrode active material, the conductive auxiliary agent, and the binder are mixed in 85% by mass, 5% by mass, and 10% by mass, respectively. N-methylpyrrolidone NMP was added as a slurry viscosity adjusting solvent and mixed to prepare a positive electrode active material slurry.

  A positive electrode active material slurry is applied to a portion other than the paste margin on one side of the current collector so that the peripheral portion (entire circumference) of the current collector becomes a paste margin with a predetermined width, and dried to form a positive electrode An active material layer was formed.

  Hard carbon is used for the negative electrode active material, acetylene black is used for the conductive auxiliary agent, N-methylpyrrolidone PVDF is used for the binder, and the negative electrode active material, the conductive auxiliary agent, and the binder are mixed in 85% by mass, 5% by mass, and 10% by mass, respectively. N-methylpyrrolidone NMP was added as a slurry viscosity adjusting solvent and mixed to prepare a negative electrode active material slurry.

  This negative electrode active material slurry is applied to the other surface of the current collector coated with the positive electrode active material on a portion other than the paste margin so that the peripheral portion (the entire circumference) of the current collector becomes a paste margin of a predetermined width. The negative electrode active material slurry was applied and dried to form a negative electrode active material layer. Thereby, the bipolar electrode which has a positive electrode active material layer and a negative electrode active material layer on both surfaces of a collector was adjusted.

<Production of stack>
The upper and lower bipolar electrodes are arranged so that the positive electrode active material layer of one bipolar electrode and the negative electrode active material layer of the other bipolar electrode are opposed to each other, and a separator is interposed between them. For each of the current collectors, a terminal portion of the wiring board is attached to one end of the current collector, and a polyethylene film having a width of 30 mm is placed as a sealing material on the adhesive margin portion of the two upper and lower bipolar electrodes arranged to face each other. Four bipolar electrodes were stacked. This completed one stack. Thereafter, the sealing material was pressed (heat and pressure) from above and below and fused to seal each layer.

  10 cc of an electrolytic solution in which 1M LiPF6 was dissolved in PC + EC (1: 1) was poured into a space secured by the sealing material placed in the adhesive margin, and the sealing part was fused while being evacuated.

  A high voltage tab having a portion in which a part of a 100 μm Al plate capable of covering the entire projection surface of the bipolar battery element extends to the outside of the battery projection surface was prepared. A bipolar battery element was sandwiched between the high voltage tabs and vacuum sealed with an aluminum laminate film so as to cover them. As a result, the entire bipolar battery element was pressurized by pressing both the upper and lower surfaces at atmospheric pressure to complete one stack (bipolar battery) in which the contact between the high voltage tab and the battery element was enhanced.

<Production of bipolar secondary battery>
Five bipolar battery elements before sandwiching the high voltage tab are arranged in series, and the five bipolar battery elements arranged in series are sandwiched between the above high voltage tabs, and are vacuum-sealed with an aluminum laminate film so as to cover them. . As a result, one bipolar secondary battery in which five stacks were stacked was completed.

  Next, the wiring board of Comparative Example 1 and Examples 1 to 6, and the wiring board of Comparative Example 2 and Examples 7 to 10 will be described individually. As described later, in Examples 1 to 6, when “the exposed conductive part area of the exposed conductive part is increased”, the area of the conductive tape is also increased in accordance with the exposed conductive part area. That is, when “the exposed conductive portion area of the exposed conductive portion is increased”, the enlarged exposed conductive portion and the current collector are bonded with the conductive tape having the same area as the increased exposed conductive portion area. Thus, when the exposed conductive part area is increased, the conductive tape having the same area as the increased exposed conductive part area is used to strengthen the adhesion between the exposed conductive part (terminal part) and the current collector. It is.

(Comparative Example 1)
A wiring board (see the upper part of FIG. 4) having the same length of four teeth was produced as the wiring board of Comparative Example 1.

Example 1
A wiring board (see the lower part of FIG. 4 or FIG. 8A) in which the tooth distance from the first reference height among the four teeth is longer is produced as the wiring board of Example 1.

(Example 2)
A wiring board (see FIG. 8B) in which the length of the teeth not at the first reference height was longer than the length of the teeth at the first reference height was produced as the wiring board of Example 2.

Example 3
A wiring board in which the length of teeth not at the first reference height is longer than the length of teeth at the first reference height, and the length of teeth at both ends in the stacking direction is longer than the length of teeth inside the stacking direction (see FIG. 8 (c)) was produced as a wiring board of Example 3.

Example 4
A wiring board (see FIG. 10 (a)) in which the tooth length is longer as the tooth is away from the first reference height and the tooth width is wider as the tooth is away from the first reference height. As produced.

(Example 5)
The wiring board (see FIG. 10B) in which the tooth length is longer as the tooth is away from the first reference height, and the exposed conductive portion area of the exposed conductive portion of the terminal portion is larger as the tooth is away from the first reference height. ) As a wiring board of Example 5.

(Example 6)
The teeth that are farther from the first reference height are longer in length, the teeth that are farther from the first reference height are wider, and the teeth that are farther from the first reference height are the exposed conductive portions of the terminal portion. A wiring board (see FIG. 10C) having a large exposed conductive part area was prepared as the wiring board of Example 6.

(Comparative Example 2)
Five wiring boards having the same pattern length (see FIG. 14) were produced as the five wiring boards of Comparative Example 2.

(Example 7)
Five wiring boards (see FIG. 15) with the pattern length being longer as the wiring board is farther from the second reference height were produced as the wiring board of Example 7.

(Example 8)
The wiring board of Example 8 has five wiring boards (see FIG. 19) in which the length of the pattern is longer as the wiring board is farther from the second reference height and the width of the pattern is wider as the wiring board is farther from the second reference height. Produced as a substrate.

Example 9
Five wiring boards in which the length of the pattern is longer as the wiring board is farther from the second reference height, and the exposed conductive part area of the exposed conductive part of the terminal part of the wiring board is larger as the wiring board is farther from the second reference height (See FIG. 16) were produced as the five wiring boards of Example 9.

(Example 10)
The longer the wiring board is away from the second reference height, the longer the length of the handle is, and the wider is the width of the upper and lower ends of the pattern, and the farther away the wiring board is from the second reference height, the exposed conductive portion of the terminal portion of the wiring board is. Five wiring boards (see FIG. 20) with a large exposed conductive part area were produced as wiring boards of Example 10.

(Example 11)
The longer the wiring board is away from the second reference height, the longer the length of the handle is, and the wider is the width of the upper and lower ends of the pattern, and the farther away the wiring board is from the second reference height, the exposed conductive portion of the terminal portion of the wiring board is. The exposed conductive part area is increased, the tooth length is increased, the tooth width (thickness) is increased (thick), and the tooth distance from the first reference height is increased and the tooth length is increased. Five wiring boards (refer to FIG. 36), in which the width of the tooth becomes wider as the tooth is farther from one reference height, were produced as the wiring board of Example 11.

  Thus, the stack of the common specification which attached the wiring board of the comparative example 1 and Examples 1-6 was produced. Moreover, the bipolar secondary battery of the common specification which attached the wiring board of the comparative example 2 and Examples 7-11 in this way was produced.

<Evaluation 1>
After charging the stack with the wiring board of Comparative Example 1 and Example 1 through the high voltage tab until the SOC becomes 100%, the shared voltage of each of the three unit cell layers is measured, The difference between the maximum value and the minimum value of the voltage of the single cell layer was calculated for the stack to which the wiring boards of Comparative Example 1 and Example 1 were attached. The difference between the maximum value and the minimum value in the case of the stack to which the wiring board of Comparative Example 1 is attached is defined as 100%, and the difference between the maximum value and the minimum value in the case of the stack to which the wiring board of Example 1 is attached is indicated in%. In Table 2.

  From Table 2, when the wiring board of Example 1 is used, the mounting position of each of the four terminal portions can be set at the same distance from the end of the electrode active material, and thus the stack (battery) is charged. In addition, it can be seen that the difference between the maximum value and the minimum value of the voltages of the three single cell layers is 49%, which is reduced to about half that in the case of using the wiring board of Comparative Example 1.

<Evaluation 2>
For the comparative example 1, the stack with the wiring board of Examples 1 to 6 and the bipolar secondary battery with the wiring board of Comparative Example 2 and Examples 7 to 11 attached in a vertical direction at a frequency of 100 Hz and an amplitude of 5 mm. A strong electric tab is used for the stack with the wiring board of Comparative Example 1 and Examples 1 to 6 and the bipolar secondary battery with the wiring board of Comparative Examples 2 and 11 installed. After charging the stack and the bipolar secondary battery until the SOC reaches 100%, the voltage of each of the three single battery layers is applied to the stack, and 3 × 5 of each single battery is applied to the bipolar secondary battery. The voltage of each battery layer was measured, and the difference between the maximum value and the minimum value of the voltage of each single cell layer was determined by comparing the stack with the wiring board of Comparative Example 1 and Examples 1 to 6, Comparative Example 2 and Example 7 Bipolar type with 10 to 10 wiring boards It was calculated for the battery. Then, assuming that the stack with the wiring board of Comparative Example 1 attached is 100%, the difference between the maximum value and the minimum value in the case of the stack with the wiring boards of Examples 1 to 6 is displayed in%, and Comparative Example 2 The difference between the maximum value and the minimum value in the case of the bipolar secondary battery to which the wiring boards of Examples 7 to 11 are attached is expressed as a percentage in the case of the bipolar secondary battery to which the wiring board is attached. It was described in Table 3.

  From Table 3, if the wiring board of Examples 1-6 is used, the vibration test of a perpendicular direction was performed, and as a result of charging a stack | stuck after that, the dispersion | variation in the voltage of each three cell layer was the wiring board of the comparative example 1. It turns out that it has decreased to almost half or less than using. If the wiring boards of Examples 1 to 6 are used, the positions where the exposed conductive parts of the four terminal parts are attached to the current collector are located at the same distance from the end of the electrode active material (electrode). It is because it can do. In particular, when using the wiring board of Example 6 in which the length of the outer two teeth is longer than the length of the inner two teeth, the wiring board is more difficult to break for a vertical vibration test. The difference between the maximum value and the minimum value is suppressed to about half that in the case where the wiring boards of the first and second embodiments are used, compared to the case where the wiring boards of the first and second embodiments are used. Further, the wiring board of Example 4 in which the tooth width is wider as the tooth is away from the first reference height, and the exposed conductive part area of the exposed conductive part of the terminal part (and by the conductive tape is closer to the tooth away from the first reference height). Even when the wiring board of the fifth embodiment having a larger bonding area is used, the effect of reducing the difference between the maximum value and the minimum value is greater than when the wiring boards of the first and second embodiments are used.

2 Stack 3 Bipolar electrode 4 Current collector 5 Positive electrode active material layer (positive electrode)
6 Negative electrode active material layer (negative electrode)
7 Electrolyte layer 11 Sealing material 15 Single cell layer (single cell)
21 Wiring board 21a, 21b, 21c, 21d Teeth 21e Trunk 21f Comb-shaped part 21g Handle 22, 23, 24, 25 Wiring 26 Insulating film (insulating board)
22a, 23a, 24a, 25a Terminal part 30 Bipolar secondary battery 31, 32, 33, 34, 35 Stack 41, 42, 43, 44, 45 Wiring board 61, 62, 63, 64, 65 Wiring board 71, 72 73, 74, 75 Wiring board 91, 92, 93, 94, 95 Wiring board

Claims (9)

Two bipolar electrodes, each having a positive electrode on one side of a current collector and a negative electrode on the opposite side, are stacked with the electrolyte sandwiched so that the positive electrode and the negative electrode face each other. A stack comprising a single cell composed of a positive electrode and a negative electrode, and a plurality of the single cells connected in series, and a wiring board for voltage detection of each of the plurality of single cells,
An insulating substrate composed of a plurality of teeth and a comb-shaped portion made of a stem integrated by bundling the plurality of teeth, and one handle connected to the comb-shaped portion;
A plurality of conductors formed of a conductive material on the insulating substrate and individually extending from the tips of the plurality of teeth to the ends of the handle and conducting the potentials of the conductors contacting the tips of the teeth to the ends of the handles. Wiring and
A terminal portion where a conductive material is exposed at the tips of the plurality of teeth,
In a stack in which each of the plurality of terminal portions is attached to a corresponding current collector,
Of the plurality of teeth, the length of the tooth attached to the current collector located at a position away from the predetermined first reference position is attached to the current collector at the first reference position or near the first reference position. A stack characterized in that it is longer than the length of a tooth, and among the plurality of teeth, a tooth that is farther from the first reference position is made thicker . The stack of claim 1 , wherein
The stack characterized by lengthening the length of a tooth which is farther from the first reference position among the plurality of teeth. The stack of claim 1 , wherein
The stack is characterized in that the attachment position of each terminal part to the current collector is the same distance from the end of the positive electrode or the negative electrode. The stack of claim 1 , wherein
The stack characterized by strengthening the adhesive force between the terminal portion and the current collector at the tip of the tooth as the tooth that is farther from the first reference position among the plurality of teeth. The stack of claim 1 , wherein
A stack characterized in that a resin current collector using a conductive material as a polymer material is used as the current collector. Two bipolar electrodes, each having a positive electrode on one side of a current collector and a negative electrode on the opposite side, are stacked with the electrolyte sandwiched so that the positive electrode and the negative electrode face each other. In a bipolar secondary battery comprising a unit cell composed of a positive electrode and a negative electrode, and a plurality of stacks in which the unit cells are connected in series.
A bipolar secondary battery, wherein a length of a pattern of a wiring board is made longer as a wiring board is more distant from a predetermined second reference position among a plurality of wiring boards provided in each stack . Two bipolar electrodes, each having a positive electrode on one side of a current collector and a negative electrode on the opposite side, are stacked with the electrolyte sandwiched so that the positive electrode and the negative electrode face each other. In a bipolar secondary battery comprising a unit cell composed of a positive electrode and a negative electrode, and a plurality of stacks in which the unit cells are connected in series.
A bipolar secondary battery characterized in that a wiring board that is farther from a predetermined second reference position among a plurality of wiring boards provided in each stack has a thicker pattern. Two bipolar electrodes, each having a positive electrode on one side of a current collector and a negative electrode on the opposite side, are stacked with the electrolyte sandwiched so that the positive electrode and the negative electrode face each other. In a bipolar secondary battery comprising a unit cell composed of a positive electrode and a negative electrode, and a plurality of stacks in which the unit cells are connected in series.
Of the plurality of wiring boards provided in each of the stacks, the wiring board that is farther from the predetermined second reference position has a stronger adhesive force between the terminal portion and the current collector at the tip of the wiring board teeth. Bipolar secondary battery. In twin electrode type secondary battery according to any one of claims 6 to 8,
A bipolar secondary battery comprising a resin current collector using a conductive material as a polymer material as the current collector.

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