Bipolar lead-acid battery

Abstract

To provide a bipolar lead-acid battery that can significantly reduce the occurrence of a short circuit caused by liquid.SOLUTION: A bipolar lead-acid battery 200 is so configured that a plurality of cell members 150 and resin substrates 110 are alternately laminated and the cell members are connected in series with one another. The cell member 150 has a positive electrode 151 including a lead layer 101 for a positive electrode and an active material layer 103 for a positive electrode, a negative electrode 152 including a lead layer 102 for a negative electrode and an active material layer 104 for a negative electrode, and an electrolyte layer 105 interposed between the positive electrode 151 and the negative electrode 152. The substrate 110 has communication holes 111a for causing one face and the other face of the substrate to communicate with each other. The bipolar lead-acid battery 200 comprises connection means 206 that is located inside the communication holes in the substrate, and electrically connects the lead layer for a positive electrode present on one face of the substrate and the lead layer for a negative electrode present on the other face of the substrate. At least part of the connection means is fixed and held over the total length in a substantially circumferential direction of an inner wall surface of the communication hole in the substrate.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a bipolar lead-acid battery. [Background technology]

[0002] In recent years, the number of power generation facilities using natural energy such as solar power and wind power has been increasing. In such power generation facilities, since it is not possible to control the amount of power generated, a storage battery is used to level out the power load. That is, when the amount of power generated is greater than the amount of consumption, the difference is charged to the storage battery, whereas when the amount of power generated is less than the amount of consumption, the difference is discharged from the storage battery. As the storage battery described above, lead-acid batteries are widely used from the viewpoints of economy and safety. For example, the following Patent Document 1 describes such a conventional lead-acid battery.

[0003] The lead acid battery described in Patent Document 1 has a resin substrate attached to the inside of a frame made of resin in the shape of a picture frame. A positive electrode lead layer and a negative electrode lead layer are disposed on one side and the other side of the substrate. The positive electrode lead layer and the negative electrode lead layer are directly bonded inside a plurality of perforations formed in the substrate. A positive electrode active material layer is adjacent to the positive electrode lead layer. A negative electrode active material layer is adjacent to the negative electrode lead layer. A glass mat (electrolytic layer) containing an electrolyte is disposed inside a frame-shaped spacer made of resin. Then, the frames and spacers are alternately stacked in a plurality of layers and assembled.

[0004] That is, the lead-acid battery described in Patent Document 1 is a bipolar lead-acid battery in which a substrate having perforations (communicating holes) connecting one side and the other side and cell members are alternately stacked in multiple layers, and the cell members have a positive electrode having a positive electrode active material layer provided on a positive electrode lead layer, a negative electrode having a negative electrode active material layer provided on a negative electrode lead layer, and an electrolytic layer interposed between the positive electrode and the negative electrode, and the positive electrode lead layer of one cell member and the negative electrode lead layer of the other cell member are joined inside the perforations (communicating holes) of the substrate, thereby connecting the cell members in series. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2014-530450 Summary of the Invention [Problem to be solved by the invention]

[0006] In the conventional bipolar lead-acid battery described in Patent Document 1 as mentioned above, for example, if electrolyte penetrates between the substrate and the positive lead layer, it may penetrate between the substrate and the negative lead layer through the perforations and cause electrolyte leakage, which may cause a drop in voltage and result in a decrease in performance.

[0007] In view of the above, an object of the present invention is to provide a bipolar lead-acid battery capable of significantly suppressing the generation of electrolyte leakage. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems, the present invention provides a bipolar lead-acid battery having the following configurations (1) to (3). (1) A bipolar lead-acid battery in which cell components and substrates made of resin are alternately stacked in multiple layers, and the cell components are connected in series. In other words, it is a bipolar lead-acid battery in which multiple cell components are stacked with gaps between them, a substrate made of resin is placed between adjacent cell components in the stacking direction, and the cell components are electrically connected in series. (2) The cell member has a positive electrode having a positive electrode active material layer on a positive electrode lead layer, a negative electrode having a negative electrode active material layer on a negative electrode lead layer, and an electrolyte layer interposed between the positive electrode and the negative electrode. (3) The substrate has a through hole that connects one surface of the substrate to the other surface of the substrate. A connection means is provided inside the through hole of the substrate to electrically connect a positive electrode lead layer present on one surface of the substrate to a negative electrode lead layer present on the other surface of the substrate. At least a part of the connection means is fixedly held over the entire circumferential length of the inner wall surface of the through hole of the substrate. Here, "approximately the entire circumferential length" does not necessarily have to be the entire circumferential length, so long as the effect of the present invention is not substantially impaired. Effect of the Invention

[0009] According to the bipolar lead-acid battery of the present invention, even if electrolyte penetrates between one of the positive electrode lead layer and the negative electrode lead layer and the substrate, the electrolyte can be prevented from penetrating through the communication holes between the other of the positive electrode lead layer and the negative electrode lead layer and the substrate, thereby significantly suppressing the occurrence of electrolyte leakage and significantly reducing the occurrence of voltage drops, making it less likely that performance degradation will occur. [Brief description of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view showing a schematic configuration of a first embodiment of a bipolar lead-acid battery according to the present invention. [Diagram 2] FIG. 2 is an enlarged view of a portion of the bipolar lead-acid battery shown in FIG. 1. [Diagram 3] FIG. 2 is a cross-sectional view showing a schematic configuration of a second embodiment of a bipolar lead-acid battery according to the present invention. [Figure 4] FIG. 4 is an enlarged view of a portion of the bipolar lead-acid battery shown in FIG. 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a bipolar lead-acid battery according to the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiment described with reference to the drawings.

[0012] First Embodiment A first embodiment of a bipolar lead-acid battery according to the present invention will be described with reference to FIGS. As shown in FIG. 1, the bipolar lead-acid battery 100 of this embodiment has a plurality of cell members 150, a plurality of internal frame units 110, a first end frame unit 120, and a second end frame unit 130. The multiple cell members 150 are stacked and arranged at intervals in the vertical direction of Fig. 1. The inner frame unit 110, the first end frame unit 120, and the second end frame unit 130 form multiple spaces (cells) C that individually accommodate the multiple cell members 150.

[0013] The internal frame unit 110 is composed of a substrate 111 having a rectangular planar shape and a rim (frame) 112 having a square frame shape (picture frame shape). The substrate 111 of the internal frame unit 110 is disposed between adjacent cell members 150 in the vertical direction of Fig. 1 (stacking direction of the cell members 150). The rims 112 constituting the multiple internal frame units 110 have joint surfaces that face each other in the vertical direction of Fig. 1 (stacking direction of the cell members 150). The substrate 111 has a plurality of communication holes 111a formed therein, which communicate between one surface side (the lower surface side in FIGS. 1 and 2) and the other surface side (the upper surface side in FIGS. 1 and 2). The substrate 111 is integrated with the inside of the rim 112. The internal frame unit 110 is made of resin. The substrate 111 is located in the middle of the thickness direction of the rim 112 (the vertical direction in Figs. 1 and 2). The rim 112 is thicker than the substrate 111 (e.g., three times thicker).

[0014] The first end frame unit 120 is composed of a first end plate 121 having a rectangular planar shape and a first end rim (frame) 122 having a square frame shape (picture frame shape). The first end plate 121 is integrated with the inside of the first end rim 122. The first end frame unit 120 is made of resin. The first end frame unit 120 surrounds the side surface and the negative electrode 152 side of the cell member 150 at one end (the lower end side in FIGS. 1 and 2 ) of the bipolar lead-acid battery 100. A first end plate 121 surrounds the negative electrode 152 side of the cell member 150, and a first end rim 122 surrounds the side surface of the cell member 150.

[0015] The first end plate 121 is disposed parallel to the base plate 111 of the internal frame unit 110, and the first end rim 122 is arranged to abut against the rim 112 of the adjacent internal frame unit 110. The first end plate 121 has a thickness greater than (e.g., twice as thick as) the substrate 111. The first end rim 122 has a thickness greater than (e.g., twice as thick as) the first end plate 121. The first end plate 121 is set to be positioned to one side (toward the bottom in FIG. 1) in the thickness direction (vertical direction in FIG. 1) of the first end rim 122.

[0016] The second end frame unit 130 is composed of a second end plate 131 having a rectangular planar shape and a square frame-shaped (picture frame-shaped) second end rim (frame) 132. The second end plate 131 is integrated with the inside of the second end rim 132. The second end frame unit 130 is made of resin. The second end frame unit 130 surrounds the side surface and the positive electrode 151 side of the cell member 150 at the other end side (the upper end side in FIG. 1 ) of the bipolar lead-acid battery 100. A second end plate 131 surrounds the positive electrode 151 side of the cell member 150, and a second end rim 132 surrounds the side surface of the cell member 150.

[0017] The second end plate 131 is disposed parallel to the base plate 111 of the internal frame unit 110, and the second end rim 132 is arranged to abut the rim 112 of the adjacent internal frame unit 110. The second end plate 131 has a thickness greater than (e.g., twice as thick as) the thickness of the substrate 111. The second end rim 132 has a thickness greater than (e.g., twice as thick as) the thickness of the second end plate 131. The second end plate 131 is set to be located toward the other side (upward in FIG. 1) in the thickness direction (up-down direction in FIG. 1) of the second end rim 132.

[0018] A positive electrode lead layer 101 is disposed on one surface of the substrate 111. A negative electrode lead layer 102 is disposed on the other surface of the substrate 111. The positive electrode lead layer 101 and the negative electrode lead layer 102, which face each other across the substrate 111, are recessed into the communicating hole 111a and directly joined by heat and pressure welding or the like. A positive electrode active material layer 103 is disposed on the positive electrode lead layer 101. A negative electrode active material layer 104 is disposed on the negative electrode lead layer 102. An electrolytic layer 105 made of a glass fiber mat or the like impregnated with an electrolytic solution such as sulfuric acid is disposed between the opposing positive electrode active material layer 103 and negative electrode active material layer 104.

[0019] A negative electrode lead layer 102 is disposed on the other surface of the first end plate 121. A negative electrode active material layer 104 is disposed on the negative electrode lead layer 102 on the first end plate 121. An electrolytic layer 105 made of a glass fiber mat or the like impregnated with an electrolytic solution such as sulfuric acid is disposed between the negative electrode active material layer 104 on the first end plate 121 and the positive electrode active material layer 103 of the opposing substrate 111. A positive electrode lead layer 101 is disposed on one surface of the second end plate 131. A positive electrode active material layer 103 is disposed on the positive electrode lead layer 101 on the second end plate 131. An electrolytic layer 105 made of a glass fiber mat or the like impregnated with an electrolytic solution such as sulfuric acid is disposed between the positive electrode active material layer 103 on the second end plate 131 and the negative electrode active material layer 104 of the opposing substrate 111. The negative lead layer 102 on the first end plate 121 is provided with a negative terminal 108 that is electrically connected to the outside of the first end plate 121. The positive lead layer 101 on the second end plate 131 is provided with a positive terminal 107 that is electrically connected to the outside of the second end plate 131.

[0020] That is, in the bipolar lead-acid battery 100 of this embodiment, a plurality of substrates 111 having communication holes 111a connecting one surface side and the other surface side and cell members 150 are alternately stacked, and the cell members 150 are connected in series. The cell member 150 has a positive electrode 151 having a positive electrode lead layer 101 and a positive electrode active material layer 103 provided thereon, a negative electrode 152 having a negative electrode lead layer 102 and a negative electrode active material layer 104 provided thereon, and an electrolytic layer 105 interposed between the positive electrode and the negative electrode. The substrate 111 is provided with a connection portion 106 as a connection means located inside the communication hole 111a and electrically connecting the positive electrode lead layer 101 present on one side of the substrate and the negative electrode lead layer 102 present on the other side of the substrate. The connection portion 106 is a portion where the portion of the positive electrode lead layer on one side of the substrate that enters inside the communication hole and the portion of the negative electrode lead layer on the other side of the substrate that enters inside the communication hole are joined.

[0021] Next, a detailed description will be given of materials forming the internal frame unit 110, the first end frame unit 120, and the second end frame unit 130. The internal frame unit 110, the first end frame unit 120, and the second end frame unit 130 are formed of a resin that has a bondability with metals (metal-bonding resin). Examples of metal-binding resins include (a) thermoplastic resins having epoxy groups or acidic functional groups in their molecular structure, (b) thermosetting resins, and (c) thermoplastic or thermosetting resins containing a coupling agent having, in its molecular structure, inorganic material-binding functional groups capable of binding to inorganic materials and organic material-binding functional groups capable of binding to organic materials.

[0022] Thermoplastic resins having epoxy groups in their molecular structure can be obtained, for example, by using glycidyl methacrylate (GMA) as a monomer. Thermoplastic resins having acidic functional groups in their molecular structure can be obtained, for example, by modifying a base thermoplastic resin with maleic anhydride (maleic anhydride-modified polypropylene, etc.). The inorganic material-binding functional group may be at least one selected from the group consisting of silyl groups, titanates, aluminates, and phosphonic acid derivatives. The organic material-binding functional group may be at least one selected from the group consisting of vinyl groups, acrylic groups, epoxy groups, amino groups, isocyanate groups, and acid anhydrides. The functional groups of such coupling agents may be appropriately selected in combination depending on the type of base resin constituting the substrate.

[0023] The base thermoplastic resin may be at least one selected from the group consisting of polyethylene, polypropylene, polyvinyl chloride, acrylonitrile-butadiene-styrene copolymer, polymethyl methacrylate, polyamide, polycarbonate, and fluororesin, and is particularly preferably polypropylene or acrylonitrile-butadiene-styrene copolymer. The thermosetting resin may be at least one selected from the group consisting of phenolic resin, epoxy resin, fural resin, polyimide, and unsaturated polyester.

[0024] In such a bipolar lead-acid battery 100, it is necessary to prepare an internal frame unit 110 in which the lead layers form the connection parts 106 on one side and the other side of the substrate and are fixed to the through holes. For this purpose, the corresponding lead layers 101, 102 are arranged together with raw materials such as resin in a mold corresponding to the shape of the internal frame unit 110, and then heat molding is performed. That is, the positive electrode lead layer 101 and the negative electrode lead layer 102 on the same substrate 111 are inserted into the through holes 111a so as to be recessed in a concave shape, and directly joined by heat pressure welding or the like to form the connection parts 106, and the connection parts 106 that have entered the through holes 111a of the substrate 111 of the lead layers 101, 102 are heat pressure welded over the entire inner wall surface of the through holes 111a. At the same time, the lead layers 101, 102 are heat pressure welded to the one side and the other side of the substrate 111.

[0025] As a result, the above-mentioned functional groups, coupling agent, and thermosetting resin in the metal-bonding resin bond to the surfaces of the lead layers 101, 102, so that the connection parts 106 of the lead layers 101, 102 are directly fixed and held over the entire inner wall surface of the communication hole 111a of the substrate 111, and are also directly fixed and held on one and the other surfaces of the substrate 111. Incidentally, in the end plates 121, 131, the corresponding lead layers 101, 102 can also be directly fixed and held on the end plates 121, 131 by placing the corresponding lead layers 101, 102 on the end plates 121, 131 and subjecting them to heat and pressure welding.

[0026] Therefore, in the bipolar lead-acid battery 100 of this embodiment, not only can it be prevented that electrolyte will not penetrate between one or the other side of the substrate 111 and each lead layer 101, 102, but even if electrolyte does penetrate between one of the positive electrode lead layer 101 and the negative electrode lead layer 102 and the top of the substrate 111, it is possible to prevent electrolyte from penetrating between the other of the positive electrode lead layer 101 and the negative electrode lead layer 102 and the top of the substrate 111 through the gap between the inner wall surface of the communicating hole 111a and each lead layer 101, 102.

[0027] Thus, in the bipolar lead-acid battery 100 of this embodiment, the connection portion 106 is fixedly held over approximately the entire circumferential length of the inner wall surface of the communication hole 111a of the substrate 110, so that the generation of electrolyte can be significantly suppressed, and therefore the occurrence of voltage drops can be significantly reduced, making performance degradation less likely to occur. It is highly preferable to subject each of the lead layers 101, 102 to a polishing process to impart surface roughness so as to enhance bonding between the substrates (end plates) 111, 121, 131 of each of the frame units 110, 120, 130 and each of the lead layers 101, 102. It is also possible to interpose a resin layer between the connection portion 106 and the communication hole 111a, which can further improve adhesion, so that the connection portion 106 is indirectly fixed and held to the inner wall surface of the communication hole 111a.

[0028] In addition, when the inner frame unit 110, the first end frame unit 120, and the second end frame unit 130 are formed of a thermoplastic resin having a functional group in its molecular structure, the ratio of the functional group in the resin is preferably 0.5% by mass or more and 10% by mass or less, and more preferably 2% by mass or more and 5% by mass or less. This is because if the above-mentioned ratio is less than 0.5% by mass, it becomes difficult to sufficiently secure the bonding force with the positive electrode lead layer 101 and the negative electrode lead layer 102, which is not preferable. On the other hand, if the above-mentioned ratio exceeds 10% by mass, the functional groups tend to react with each other, which may lead to an increase in viscosity and a decrease in moldability, which is not preferable.

[0029] In addition, when the inner frame unit 110, the first end frame unit 120, and the second end frame unit 130 are formed of a resin containing a coupling agent, the ratio of the coupling agent in the resin is preferably 0.5% by mass or more and 10% by mass or less, and more preferably 2% by mass or more and 5% by mass or less. This is because if the above-mentioned ratio is less than 0.5% by mass, it becomes difficult to sufficiently secure the bonding force with the positive electrode lead layer 101 and the negative electrode lead layer 102, which is not preferable. On the other hand, if the above-mentioned ratio exceeds 10% by mass, the functional groups tend to react with each other, which may lead to an increase in viscosity and the generation of lumps, thereby causing a decrease in moldability, which is not preferable.

[0030] Furthermore, when the above-mentioned fixing and holding is performed, the temperature is preferably 200° C. or more and 250° C. or less, the pressure is preferably 0.5 MPa or more and 5 MPa or less, and the time is preferably 10 seconds or more and 20 minutes or less. This is because if the temperature is less than 200°C, the time required for bonding will be too long, which is undesirable. If the temperature exceeds 250°C, the substrates (end plates) 111, 121, 131 will become too soft and may be deformed by the pressure, which is undesirable. If the pressure is less than 0.5 MPa, the time required for bonding will be too long, which is undesirable. If the pressure exceeds 5 MPa, the pressure applied may cause deformation, which is undesirable. If the time is less than 10 seconds, it will be difficult to obtain sufficient bonding strength, which is undesirable. If the time exceeds 20 minutes, energy will be wasted, which is undesirable.

[0031] Second Embodiment A bipolar lead-acid battery according to a second embodiment of the present invention will be described with reference to Figures 3 and 4. However, for parts similar to those in the above-described embodiment, the same reference numerals as those used in the description of the above-described embodiment are used, and descriptions that overlap with those in the above-described embodiment will be omitted. As shown in FIGS. 3 and 4, a conductor 206, which is a connection means made of lead and electrically connects the positive electrode lead layer 101 and the negative electrode lead layer 102, is inserted into the communication hole 111a of the substrate 111.

[0032] In other words, in the bipolar lead-acid battery 100 of the first embodiment, a connection portion 106 is provided as a connection means, i.e., "a portion where the portion of the positive electrode lead layer on one side of the substrate that enters inside the communicating hole and the portion of the negative electrode lead layer on the other side of the substrate that enters inside the communicating hole" is directly joined, whereas in the bipolar lead-acid battery 200 of the present embodiment, a conductor 206 is inserted into the communicating hole 111a of the substrate 111 as a connection means. In such a bipolar lead-acid battery 200, it is necessary to prepare an internal frame unit 110 with the conductor 206 inserted into the through hole of the substrate. For this purpose, the corresponding lead layers 101, 102 and the conductor 206 are arranged together with raw materials such as resin in a mold corresponding to the shape of the internal frame unit 110, and then a hot molding process is performed.

[0033] As a result, the above-mentioned functional groups, coupling agents, and thermosetting resins in the metal-bonding resin bond to the surfaces of the conductor 206 and each lead layer 101, 102, so that the conductor 206 is directly fixed and held over the entire inner wall surface of the communicating hole 111a of the substrate 111, and each lead layer 101, 102 is directly fixed and held on the opposing surfaces of the substrates (end plates) 111, 121, 131 of each frame unit 110, 120, 130. Therefore, in the bipolar lead-acid battery 200 of this embodiment, as in the case of the first embodiment described above, it is possible to prevent electrolyte from penetrating between the substrate 111 and each lead layer 101, 102. Even if electrolyte does penetrate between one of the positive electrode lead layer 101 and the negative electrode lead layer 102 and the substrate 111, the electrolyte can be prevented from penetrating between the other of the positive electrode lead layer 101 and the negative electrode lead layer 102 and the substrate 111 through the gap between the inner wall surface of the communicating hole 111a and the conductor 206.

[0034] Thus, according to the bipolar lead-acid battery 200 of this embodiment, the conductor 206 is fixed and held over approximately the entire circumferential length of the inner wall surface of the communication hole 111a of the substrate 110. As a result, as in the case of the previously described embodiment, the generation of electrolyte can be significantly suppressed, and the occurrence of voltage drops can be significantly reduced, making performance degradation less likely to occur. It is highly preferable to subject each of the lead layers 101, 102 and the conductor 206 to a polishing process to impart surface roughness in order to enhance bonding between the substrates (end plates) 111, 121, 131 of each of the frame units 110, 120, 130 and each of the lead layers 101, 102 and the conductor 206. It is also possible to interpose a resin layer between conductor 206 and communication hole 111a, which can further improve adhesion, so that conductor 206 is indirectly fixed and held to the inner wall surface of communication hole 111a.

[0035] Other Embodiments In the bipolar lead-acid batteries 100, 200 of the first and second embodiments described above, the connection portion 106 and the conductor 206 are fixed and held over the entire inner wall surface of the communicating hole 111a, and the lead layers 101, 102 are fixed and held over the opposing surface of the substrate 111. However, the present invention is not limited to this, and the object of the present invention can be achieved as long as at least a part of the connection portion 106 and the conductor 206 are fixed and held over approximately the entire circumferential length of the inner wall surface of the communicating hole 111a.

[0036] However, it is preferable that the connection portion 106 and the conductor 206 are fixed over the entire inner wall surface of the communication hole 111a as in the bipolar lead-acid batteries 100 and 200 of the first and second embodiments described above, since this can more reliably suppress the generation of electrolyte leakage. In addition, it is very preferable that the lead layers 101 and 102 are directly fixed and held by heat and pressure welding to the opposing surface of the substrate 111 as in the bipolar lead-acid batteries 100 and 200 of the first and second embodiments, since this can more reliably suppress the generation of electrolyte leakage. [Industrial Applicability]

[0037] INDUSTRIAL APPLICABILITY The bipolar lead-acid battery according to the present invention can greatly suppress the generation of electrolyte leakage, greatly reduce the occurrence of voltage drops, and make performance degradation less likely to occur, and therefore can be extremely beneficially utilized in industry. [Explanation of symbols]

[0038] 100 Bipolar lead-acid battery 101 Lead layer for positive electrode 102 Lead layer for negative electrode 103 Active material layer for positive electrode 104 Active material layer for negative electrode 105 Electrolytic layer 106 Connection part (connection means) 107 Positive terminal 108 Negative terminal 109 Outer packaging 109a Vent valve 110 Internal frame unit 111 Substrate 111a Communication hole 112 Rims 120 First end frame unit 121 First end plate 122 First end rim 130 Second end frame unit 131 Second End Plate 132 Second end rim 150 Cell member 151 Positive electrode 152 Negative electrode 200 Bipolar lead-acid battery 206 Conductors (connection means) C Cell (space for accommodating cell components)

Claims

1. A bipolar lead-acid battery in which cell members and substrates formed of resin are alternately stacked in a plurality of layers, and the cell members are connected in series, The cell member has a positive electrode having a positive electrode active material layer on a positive electrode lead layer, a negative electrode having a negative electrode active material layer on a negative electrode lead layer, and an electrolytic layer interposed between the positive electrode and the negative electrode, the substrate has a through hole that connects one surface of the substrate to the other surface of the substrate; a connecting means located inside the through hole of the substrate, electrically connecting the positive electrode lead layer present on one side of the substrate and the negative electrode lead layer present on the other side of the substrate; At least a portion of the connection means is fixedly held over the entire circumferential length of the inner wall surface of the communication hole of the substrate, The connection means is a conductor inserted into the communication hole of the substrate.

2. 2. The bipolar lead-acid battery according to claim 1, wherein said connecting means is fixed and held directly on said substrate.

3. 3. The bipolar lead-acid battery according to claim 1, wherein the resin is a metal-bonding resin.

4. 4. The bipolar lead-acid battery according to claim 3, wherein the metal-binding resin is a thermoplastic resin having an acidic functional group in its molecular structure.

5. 4. The bipolar lead-acid battery according to claim 3, wherein the metal-binding resin is a thermosetting resin.

6. 4. The bipolar lead-acid battery according to claim 3, wherein the metal-binding resin is a thermoplastic resin or a thermosetting resin containing a coupling agent having in its molecular structure an inorganic material-binding functional group capable of binding to an inorganic material and an organic material-binding functional group capable of binding to an organic material.

7. 7. The bipolar lead-acid battery according to claim 6, wherein the inorganic material-binding functional group is at least one selected from the group consisting of a silyl group, a titanate, an aluminate, and a phosphonic acid derivative.

8. 7. The bipolar lead-acid battery according to claim 6, wherein the organic material-binding functional group is at least one selected from the group consisting of a vinyl group, an acrylic group, an epoxy group, an amino group, an isocyanate group, and an acid anhydride group.

9. The bipolar lead-acid battery according to claim 4 or 6, wherein the thermoplastic resin is at least one selected from the group consisting of polyethylene, polypropylene, polyvinyl chloride, acrylonitrile-butadiene-styrene copolymer, polymethyl methacrylate, polyamide, polycarbonate, and fluororesin.

10. 7. The bipolar lead-acid battery according to claim 5, wherein the thermosetting resin is at least one selected from the group consisting of phenolic resin, epoxy resin, polyimide, and unsaturated polyester.

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