Bipolar battery

Abstract

To provide a bipolar battery manufactured by a method in which an electrolyte injection process is carried out after completing an assembly process of a structural portion of a main body, which makes it easy to impregnate the entire inside of a separator in a compressed state with electrolyte during the electrolyte injection process.SOLUTION: In a bipolar battery 100, a plurality of cell members 110 are individually housed in a plurality of spaces formed by a plurality of space forming members 120. End faces of frames constituting the plurality of space forming members 120 are joined to form a main body 101. The main body 101 includes a plurality of side plates formed of side plate portions of the plurality of frames, and a liquid injection port 180 for each of the plurality of spaces is formed in at least one of the plurality of side plates. A protrusion 125 is formed on the inner surface of the side plate facing the cell member 110.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a bipolar storage 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. As such a conventional lead-acid battery, for example, a bipolar storage battery described in Patent Document 1 below is known.

[0003] This bipolar storage battery has a resin substrate attached to the inside of a frame made of resin in a picture frame shape. Lead layers are arranged on both sides of the substrate. A positive electrode active material layer is adjacent to the lead layer on one side of the substrate, and a negative electrode active material layer is adjacent to the lead layer on the other side of the substrate. The substrate also has a frame-shaped resin spacer, and a glass mat impregnated with an electrolyte is arranged on the inside of the spacer. The frames and spacers are alternately stacked in a plurality of layers, and the frames and spacers are bonded with an adhesive or the like. The lead layers on both sides of the substrate are connected via through holes provided in the substrate.

[0004] That is, the bipolar storage battery described in Patent Document 1 includes a positive electrode having a positive electrode current collector and a positive electrode active material layer, a negative electrode having a negative electrode current collector and a negative electrode active material layer, and a separator (glass mat) interposed between the positive electrode and the negative electrode, and has a plurality of cell members stacked with spaces between them, and a plurality of space-forming members that form a plurality of spaces to individually accommodate the plurality of cell members.

[0005] The space-forming member includes a substrate that covers at least one of the positive and negative sides of the cell member, and a frame (frames of the bipolar plate and end plate, and spacers) that surrounds the side of the cell member. The cell members and the substrates of the space-forming member are alternately arranged in a stacked state, the cell members are electrically connected in series, and the opposing surfaces of adjacent frames are joined to each other to form the body of the bipolar storage battery. The side plates of the body are composed of the frames of the space-forming members.

[0006] As a method for producing the bipolar storage battery having the above structure, for example, the following method can be mentioned. An injection port (a hole for pouring electrolyte into each cell) or a recess constituting an injection port is provided in advance at a predetermined position on the frame (a position that will be the upper side of the main body in the electrolyte injection process) that penetrates into each of the above-mentioned multiple spaces. Then, first, the structural part of the main body is assembled. That is, a plurality of cell members and a plurality of substrates of space forming members are alternately arranged in a stacked state, the cell members are electrically connected in series, and the opposing surfaces of adjacent frames are joined together. Next, an electrolyte is poured into each space through each injection port, and the separator is impregnated with the electrolyte. That is, in this method, the electrolyte injection process is performed after the assembly process of the structural part of the main body is completed. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 6124894 Summary of the Invention [Problem to be solved by the invention]

[0008] In a bipolar storage battery with the above structure, since the active material layer is easily peeled off or dropped off from the current collector plate, strong pressure is applied to the cell components to prevent this. Therefore, when manufacturing a bipolar storage battery with the above structure by the above method, it is difficult to impregnate the entire inside of the separator, which is in a compressed state, with the electrolyte in the electrolyte injection step. An object of the present invention is to provide a bipolar storage battery having the above-mentioned structure, which can facilitate impregnating the entire inside of the separator in a compressed state with the electrolyte during the electrolyte injection step when producing the battery by the above-mentioned method. [Means for solving the problem]

[0009] One embodiment of the present invention for solving the above problems is a bipolar storage battery having the following configurations (1) to (3). (1) A battery comprising: a positive electrode having a positive electrode active material layer, a negative electrode having a negative electrode active material layer, and a separator interposed between the positive electrode and the negative electrode; and a plurality of cell members arranged in a stacked arrangement with a gap therebetween; and a plurality of space-forming members forming a plurality of spaces for individually accommodating the plurality of cell members. The space-forming members include a substrate covering at least one of the positive electrode side and the negative electrode side of the cell members, and a frame surrounding the side surface of the cell members. The cell members and the substrates of the space-forming members are arranged in an alternately stacked state, and the plurality of cell members are electrically connected in series. Opposing surfaces of adjacent frame members are joined to form a main body.

[0010] (2) The main body has a plurality of side plates formed by side plate portions of a plurality of the frame bodies, and at least one of the side plates is formed with a liquid injection port for each of the plurality of spaces.

[0011] (3) The side plate has a protrusion on the inner surface facing the cell member. Effect of the Invention

[0012] According to the bipolar storage battery of the present invention, when the battery is manufactured by a method in which an electrolyte injection step is performed after completing the assembly step of the structural parts of the main body, it is possible to easily impregnate the electrolyte into the entire inside of the separator, which is in a compressed state, during the electrolyte injection step. [Brief description of the drawings]

[0013] [Figure 1] 1 is a perspective view showing a bipolar storage battery according to an embodiment of the present invention. [Diagram 2] 2 is a cross-sectional view taken along line AA in FIG. 1. [Diagram 3] 2 is a perspective view showing the bipolar storage battery of FIG. 1 with the lid lifted off the main body. FIG. [Figure 4] FIG. 2 is a cross-sectional view of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of the present invention will be described, but the present invention is not limited to the embodiment shown below. In the embodiment shown below, technically preferable limitations are imposed for carrying out the present invention, but these limitations are not essential requirements of the present invention. In the following, a bipolar lead-acid battery will be described as an example of a bipolar storage battery.

[0015] [Overall structure] First, the overall configuration of the bipolar lead-acid battery of this embodiment will be described. As shown in Fig. 1, the bipolar lead-acid battery 100 of this embodiment is composed of a body 101 and a lid 190. Fig. 1 shows the installed state of the bipolar lead-acid battery 100 in an electrolyte injection process, and the up-down direction of the body 101 in this state is the X direction. The lid 190 is fixed to one end face in the X direction of the body 101 (the upper face during the electrolyte injection process). In other words, the lid 190 is disposed at a position that will be the upper side of the body 101 during the electrolyte injection process.

[0016] As shown in Fig. 2, the main body 101 has a plurality of cell members 110, a plurality of biplates (space forming members) 120, a first end plate (space forming member) 130, and a second end plate (space forming member) 140. Although Fig. 2 shows a bipolar lead-acid battery 100 in which three cell members 110 are stacked, the number of cell members 110 is determined by the battery design. In addition, the number of biplates 120 is determined according to the number of cell members 110.

[0017] The stacking direction of the cell members 110 is the Z direction (the vertical direction in FIG. 2), and the direction perpendicular to the paper surface of FIG. 2 is the Y direction. The cell member 110 includes a positive electrode 111, a negative electrode 112, and a separator (electrolyte layer) 113. The separator 113 is impregnated with an electrolyte. The positive electrode 111 includes positive electrode lead foils (positive electrode current collectors) 111a and 111aa, and a positive electrode active material layer 111b. The negative electrode 112 includes negative electrode lead foils (negative electrode current collectors) 112a and 112aa, and a negative electrode active material layer 112b. The separator 113 is interposed between the positive electrode 111 and the negative electrode 112. In the cell member 110, the positive electrode lead foils 111a and 111aa, the positive electrode active material layer 111b, the separator 113, the negative electrode active material layer 112b, and the negative electrode lead foils 112a and 112aa are laminated in this order.

[0018] The dimension (thickness) in the Z direction is larger (thicker) for the positive electrode lead foil 111a than for the negative electrode lead foil 112a, and the positive electrode active material layer 111b is larger (thicker) than for the negative electrode active material layer 112b. The multiple cell members 110 are stacked and arranged at intervals in the Z direction, and the substrate 121 of the biplate 120 is arranged in this interval. In other words, the multiple cell members 110 are stacked with the substrate 121 of the biplate 120 sandwiched between them.

[0019] The plurality of biplates 120, the first end plate 130, and the second end plate 140 are members (space forming members) for forming a plurality of spaces (cells) C that accommodate the plurality of cell members 110 individually. The biplate 120 is composed of a substrate 121 having a rectangular planar shape, a frame 122 covering the four end faces of the substrate 121, and pillars 123 protruding vertically from both sides of the substrate 121, and the substrate 121, frame 122, and pillars 123 are integrally formed of synthetic resin. The number of pillars 123 protruding from each side of the substrate 121 may be one or more.

[0020] In the Z direction, the dimension of frame body 122 is larger than the dimension (thickness) of substrate 121, and the dimension between the protruding end faces of column portion 123 is the same as the dimension of frame body 122. Then, by stacking a plurality of biplates 120 with frame bodies 122 and column portions 123 in contact with each other, a space C is formed between substrates 121, and the dimension of space C in the Z direction is maintained by column portions 123 in contact with each other.

[0021] The positive electrode lead foils 111a, 111aa, the positive electrode active material layer 111b, the negative electrode lead foils 112a, 112aa, the negative electrode active material layer 112b, and the separator 113 are respectively formed with through holes 111c, 111d, 112c, 112d, and 113a for inserting the column portions 123. The substrate (main substrate) 121 of the biplate 120 has a plurality of conductive holes (through holes for arranging conductive bodies for conducting adjacent cell members) 121a penetrating the plate surface. A first recess 121b is formed on one surface of the substrate 121, and a second recess 121c is formed on the other surface. The first recess 121b is deeper than the second recess 121c. The dimensions in the X and Y directions of the first recess 121b and the second recess 121c correspond to the dimensions in the X and Y directions of the positive electrode lead foil 111a and the negative electrode lead foil 112a.

[0022] The substrate 121 of the biplate 120 is disposed between the adjacent cell members 110 in the Z direction. The substrate 121 of the biplate 120 is a substrate that covers both the positive electrode 111 side of the cell member 110 and the negative electrode 112 side of the adjacent cell member 110. The positive electrode lead foil 111a of the cell member 110 is disposed in a first recess 121b of the substrate 121 of the biplate 120 via an adhesive layer 150. In other words, the positive electrode lead foil 111a is fixed to the surface of the substrate 121 on the positive electrode 111 side (the bottom surface of the first recess 121b) with an adhesive.

[0023] Moreover, the negative electrode lead foil 112a of the cell member 110 is placed in the second recess 121c of the substrate 121 of the biplate 120 via the adhesive layer 150. That is, the negative electrode lead foil 112a is fixed to the surface of the substrate 121 on the negative electrode 112 side (the bottom surface of the second recess 121c) with the adhesive. A conductor 160 is disposed in the conductive hole 121a of the substrate 121 of the biplate 120, and both end faces of the conductor 160 are in contact with and connected to the positive electrode lead foil 111a and the negative electrode lead foil 112a. In other words, the positive electrode lead foil 111a and the negative electrode lead foil 112a are electrically connected by the conductor 160. As a result, all of the multiple cell members 110 are electrically connected in series.

[0024] The first end plate 130 is composed of a substrate 131 covering the positive electrode side of the cell member 110, a frame 132 surrounding the side surface of the cell member 110, and a column portion 133 protruding vertically from one surface of the substrate 131 (the surface facing the substrate 121 of the biplate 120 arranged on the most positive electrode side). The planar shape of the substrate 131 is rectangular, and the four end surfaces of the substrate 131 are covered with the frame 132, and the substrate 131, the frame 132 and the column portion 133 are integrally formed of a synthetic resin. The number of the column portions 133 protruding from one surface of the substrate 131 may be one or more, and they are made to correspond to the column portions 123 of the biplate 120 with which the column portions 133 come into contact.

[0025] In the Z direction, the dimension of frame 132 is larger than the dimension (thickness) of substrate 131, and the dimension between the protruding end faces of column portion 133 is the same as the dimension of frame body 132. By stacking frame body 132 and column portion 133 in contact with frame body 122 and column portion 123 of biplate 120 arranged on the outermost side (positive electrode side), a space C is formed between substrate 121 of biplate 120 and substrate 131 of first endplate 130, and the dimension of space C in the Z direction is maintained by column portion 123 of biplate 120 and column portion 133 of first endplate 130, which are in contact with each other.

[0026] Through holes 111c, 111d, and 113a for inserting the columnar portions 133 are formed in the positive electrode lead foil 111aa, the positive electrode active material layer 111b, and the separator 113 of the cell member 110 arranged on the outermost side (positive electrode side), respectively. A recess 131b is formed on one surface of the substrate 131 of the first end plate 130. The dimension in the X direction of the recess 131b corresponds to the dimension in the X direction of the positive lead foil 111aa. The dimension in the Z direction of the positive lead foil 111aa arranged on one surface of the substrate 131 of the first end plate 130 is larger than the dimension in the Z direction of the positive lead foil 111a arranged on one surface of the substrate 121 of the biplate 120.

[0027] The positive electrode lead foil 111aa of the cell member 110 is disposed in the recess 131b of the substrate 131 of the first end plate 130 via an adhesive layer 150. That is, the positive electrode lead foil 111aa is fixed to the surface of the substrate 131 on the positive electrode 111 side (the bottom surface of the recess 131b) with an adhesive. The first end plate 130 also includes a positive electrode terminal electrically connected to the positive electrode lead foil 111aa in the recess 131b.

[0028] The second end plate 140 is composed of a substrate 141 covering the negative electrode side of the cell member 110, a frame 142 surrounding the side surface of the cell member 110, and a column portion 143 protruding vertically from one surface of the substrate 141 (the surface facing the substrate 121 of the biplate 120 arranged on the most negative electrode side). The planar shape of the substrate 141 is rectangular, and the four end surfaces of the substrate 141 are covered with the frame 142, and the substrate 141, the frame 142, and the column portion 143 are integrally formed of a synthetic resin. The number of the column portions 143 protruding from one surface of the substrate 141 may be one or more, and they are made to correspond to the column portions 123 of the biplate 120 with which the column portions 143 come into contact.

[0029] In the Z direction, the dimension of frame 142 is larger than the dimension (thickness) of substrate 131, and the dimension between the protruding end faces of two pillar portions 143 is the same as the dimension of frame body 142. By stacking frame body 142 and pillar portion 143 in contact with frame body 122 and pillar portion 123 of biplate 120 arranged on the outermost side (negative electrode side), a space C is formed between substrate 121 of biplate 120 and substrate 141 of second endplate 140, and the dimension of space C in the Z direction is maintained by pillar portion 123 of biplate 120 and pillar portion 143 of second endplate 140, which are in contact with each other.

[0030] Through holes 112c, 112d, and 113a for inserting the columnar portions 143 are formed in the negative electrode lead foil 112aa, the negative electrode active material layer 112b, and the separator 113 of the cell member 110 arranged on the outermost side (negative electrode side), respectively. A recess 141b is formed on one surface of the substrate 141 of the second end plate 140. The dimensions in the X and Y directions of the recess 141b correspond to the dimensions in the X and Y directions of the negative lead foil 112aa. The dimension in the Z direction of the negative lead foil 112aa arranged on one surface of the substrate 141 of the second end plate 140 is larger than the dimension in the Z direction of the negative lead foil 112a arranged on the other surface of the substrate 121 of the biplate 120.

[0031] The negative electrode lead foil 112aa of the cell member 110 is disposed in the recess 141b of the substrate 141 of the second end plate 140 via the adhesive layer 150. That is, the negative electrode lead foil 112aa is fixed to the surface of the substrate 141 on the negative electrode 112 side (the bottom surface of the recess 141b) with an adhesive. The second end plate 140 also includes a negative electrode terminal electrically connected to the negative electrode lead foil 112aa in the recess 141b.

[0032] Furthermore, the opposing surfaces of adjacent frame bodies 122, 132, 142 are joined by vibration welding, and the biplate 120, the first end plate 130, and the second end plate 140 are integrated together. As can be seen from the above description, the biplate 120 is a space-forming member that includes a substrate 121 that covers both the positive electrode side and the negative electrode side of the cell member 110, and a frame 122 that surrounds the side surface of the cell member 110. The first end plate 130 is a space-forming member that includes a substrate 131 that covers only the positive electrode side (one of the positive electrode side or the negative electrode side) of the cell member 110, and a frame 132 that surrounds the side surface of the cell member 110.

[0033] Moreover, the second end plate 140 is a space forming member including a substrate 141 that covers only the negative electrode side (one of the positive electrode side and the negative electrode side) of the cell member 110, and a frame 142 that surrounds the side surface of the cell member 110. In other words, the substrates 121, 131, and 141 are substrates that cover at least one of the positive electrode side and the negative electrode side of the cell member 110, and the substrate 121 is a substrate that covers both the positive electrode side and the negative electrode side of the cell member 110. Moreover, the substrate 121 of the biplate 120 is a substrate (main substrate) that is disposed between the cell members 110.

[0034] [Details of the frame and lid] 2 to 4, the frame body 122 of the biplate 120, the frame body 132 of the first end plate 130, and the frame body 142 of the second end plate 140 are each composed of four side plate portions. The main body 101 has four side plates that constitute both ends in the X direction and both ends in the Y direction, and each side plate is composed of the side plate portion of the frame bodies 122, 132, and 142.

[0035] In Figure 3, the positions of the first side plate portion 132a, the second side plate portion 132b, the third side plate portion 132c, and the fourth side plate portion 132d are shown for the frame body 132 of the first end plate 130, but corresponding side plate portions are also present at positions overlapping these positions for the frame body 122 of the biplate 120 and the frame body 142 of the second end plate 140. Fig. 2 shows only the third side plate portions 122c, 132c, and 142c of the frames 122, 132, and 142. Fig. 4 shows the first side plate portion 122a, the second side plate portion 122b, and the fourth side plate portion 122d of the frame 122.

[0036] 2 and 4, protrusions 125, 135, 145 facing the side surface of the cell member 110 are formed on the inner surface of each of the frame bodies 122, 132, 142. The protrusions 125, 135, 145 are formed in the form of continuous stripes along the X direction and the Y direction on the inner surface of the frame bodies 122, 132, 142, respectively. As shown in Fig. 2, in this embodiment, the centers in the Z direction of the protrusions 125, 135, 145 are located at the same position as or near the position of the joint surface between the adjacent frame bodies 122.

[0037] As shown in FIGS. 2 and 4, in this embodiment, the tips of the protrusions 125, 135, and 145 are in contact with the separator 113 of the cell member 110. 3, a side plate disposed at one end of the main body 101 in the X direction is formed by first side plate portions 122a, 132a, 142a of the frames 122, 132, 142. A lid 109 is fixed onto this side plate, that is, to one end surface of the main body 101 in the X direction.

[0038] Three liquid inlet ports (holes for pouring electrolyte) 180 for each of the cells C are formed along the Y direction in a side plate forming one end surface in the X direction of the main body 101. The liquid inlet ports 180 are holes penetrating the plate surface of the side plate. Each liquid inlet port 180 is formed as a pair of opposing recesses 181. The recesses 181 are formed in the side plates 122a, 132a, 142a of the respective frames 122, 132, 142. The recesses 181 penetrate the side plates 122a, 132a, 142a in the X direction, and are recessed in a semicircular arc shape from both end surfaces in the Z direction in the frame 122, and are recessed in a semicircular arc shape from one end surface in the Z direction in the frame 132, 142.

[0039] 2 and 3, the lid 109 has electrolyte supply ports 191 at three positions along the Z direction at the center in the Y direction. As shown in Fig. 4, each of the liquid injection ports 180 extends along the X direction, and each of the electrolyte supply ports 191 is disposed directly above each of the liquid injection ports 180 disposed at the center in the Y direction.

[0040] [Manufacturing method] The bipolar lead-acid battery 100 of this embodiment can be manufactured, for example, by a method including the steps described below.

[0041] <Production process of biplate with lead foil for positive and negative electrodes> First, the substrate 121 of the biplate 120 is placed on a workbench with the first recess 121b facing up, adhesive is applied to the first recess 121b, and the positive electrode lead foil 111a is placed in the first recess 121b. At that time, the column portion 123 of the biplate 120 is passed through the through hole 111c of the positive electrode lead foil 111a. Next, the adhesive is hardened to form an adhesive layer 150. As a result, the positive electrode lead foil 111a is attached to one surface of the substrate 121.

[0042] Next, the substrate 121 is placed on a workbench with the second recess 121c side facing up, and the conductor 160 is inserted into the conductive hole 121a. Next, adhesive is applied to the second recess 121c, and the negative electrode lead foil 112a is placed in the second recess 121c. At that time, the column portion 123 of the biplate 120 is passed through the through hole 112c of the negative electrode lead foil 112a. Next, the adhesive is hardened to form an adhesive layer 150. As a result, the negative electrode lead foil 112a is attached to the other surface of the substrate 121.

[0043] Next, resistance welding is performed to connect the conductor 160 to the positive lead foil 111a and the negative lead foil 112a. This results in a biplate 120 (a biplate with positive and negative lead foils) in which the positive lead foil 111a and the negative lead foil 112a are fixed to both sides of the substrate 121. A required number of such biplates with positive and negative lead foils are prepared.

[0044] <Production process of end plate with lead foil for positive electrode> The substrate 131 of the first end plate 130 is placed on a workbench with the recess 131b facing up, adhesive is applied to the recess 131b, and the positive electrode lead foil 111aa is placed in the recess 131b. At this time, the column portion 133 of the end plate 130 is passed through the through hole 111c of the positive electrode lead foil 111aa. The adhesive is cured to form an adhesive layer 150. This results in a first end plate 130 (end plate with positive electrode lead foil) in which the positive electrode lead foil 111aa is fixed to one surface of the substrate 131.

[0045] <Production process of end plate with lead foil for negative electrode> The substrate 141 of the second end plate 140 is placed on a workbench with the recess 141b facing up, adhesive is applied to the recess 141b, and the negative electrode lead foil 112aa is placed in the recess 141b. At this time, the column portion 143 of the second end plate 140 is passed through the through hole 112c of the negative electrode lead foil 112aa. The adhesive is cured to form an adhesive layer 150. This results in a second end plate 140 (end plate with negative electrode lead foil) in which the negative electrode lead foil 112aa is fixed to one surface of the substrate 141.

[0046] <The process of stacking and joining plates> First, the first end plate 130 to which the positive electrode lead foil 111a is fixed is placed on a workbench with the positive electrode lead foil 111a facing up, and the positive electrode active material layer 111b is placed on the positive electrode lead foil 111a. At that time, the column portion 133 of the first end plate 130 is passed through the through hole 111d of the positive electrode active material layer 111b. Next, the separator 113 and the negative electrode active material layer 112b are placed in this order on the positive electrode active material layer 111b.

[0047] Next, the biplate 120 with the positive and negative lead foils fixed thereto is placed with the negative lead foil 112a side facing down on the first end plate 130 in this state. At this time, the column portion 123 of the biplate 120 is passed through the through hole 113a of the separator 113 and the through hole 112d of the negative active material layer 112b, and placed on the column portion 133 of the first end plate 130, and the frame 122 of the biplate 120 is placed on the frame 132 of the first end plate 130.

[0048] In this state, first end plate 130 is fixed, and vibration welding is performed while vibrating biplate 120 in the diagonal direction of substrate 121. As a result, frame body 122 of biplate 120 is joined onto frame body 132 of first end plate 130, and column portion 123 of biplate 120 is joined onto column portion 133 of first end plate 130. Burrs generated on the inner surface of the joint between frame body 132 of first end plate 130 and frame body 122 of biplate 120 due to vibration welding become protrusions 135 toward the side surface of separator 113 of cell member 110.

[0049] As a result, the biplate 120 is joined onto the first end plate 130, the cell member 110 is placed in the space C formed by the first end plate 130 and the biplate 120, and the positive electrode lead foil 111a is exposed on the upper surface of the biplate 120. Next, the positive electrode active material layer 111b, the separator 113, and the negative electrode active material layer 112b are placed in this order on the combined body thus obtained, in which the biplate 120 is joined to the first end plate 130, and then another biplate 120 with positive and negative lead foils is placed with the negative electrode lead foil 112a side facing down.

[0050] In this state, the combined body is fixed, and vibration welding is performed while vibrating the biplate 120 with the separate positive and negative lead foils in the diagonal direction of the substrate 121. This vibration welding process is continued until the required number of biplates 120 are joined onto the first end plate 130. Then, burrs generated on the inner surfaces of the joints between the frames 122 of the biplates 120 in each vibration welding process become protrusions 125 toward the side surfaces of the separators 113 of the cell member 110.

[0051] Finally, the positive electrode active material layer 111b, the separator 113, and the negative electrode active material layer 112b are placed in this order on the uppermost biplate 120 of the combined assembly in which all the biplates 120 are joined, and then the second end plate 140 is placed with the negative electrode lead foil 112aa side facing downward. In this state, the combined body is fixed, and vibration welding is performed while vibrating the second end plate 140 in the diagonal direction of the substrate 141. As a result, the second end plate 140 is joined onto the uppermost biplate 120 of the combined body to which all the biplates 120 have been joined. Then, burrs generated on the inner surface of the joint between the frame 122 of the biplate 120 and the frame 142 of the second end 140 due to the vibration welding become protrusions 145 toward the side surface of the separator 113 of the cell member 110.

[0052] By carrying out each of the above steps, the cell members and the substrates of the space forming members are alternately arranged in a stacked state, the cell members are electrically connected in series, and the opposing surfaces of the adjacent frames are joined together. In other words, the structural part of the main body 101 can be assembled. In the above explanation, the stacking order is described as being from the first end plate 130 to the second end plate 140, but the stacking order may also be reversed, from the second end plate 140 to the first end plate 130.

[0053] <Process of fixing the lid to the main body> In the structural portion of the main body 101 assembled as described above, a circular liquid injection port 180 is formed at the position of each space C of the side plate located at one end of the main body 101 in the X direction by a recess 181 of the opposing frame body. 3, this main body 101 is placed with the surface on which the liquid injection port 180 is formed (one end surface in the X direction) facing up, and the lid 190 is placed on top of it so that the electrolyte supply port 191 is aligned with the liquid injection port 180 at the center of the main body 101 in the Y direction, and the lid 190 is fixed to the main body 101. This results in the state shown in FIG.

[0054] <Electrolyte injection process> Next, in the state shown in FIG. 1, an electrolyte is supplied from each electrolyte supply port 191 of the lid 190. 4, the electrolyte supplied to each electrolyte supply port 191 of the lid 190 enters a passage formed between the lid 190 and the main body 101, then enters each cell C from the three electrolyte inlets 180, and is supplied to the separator 113 of the cell member 110 arranged in the cell C. At that time, the electrolyte that has entered each cell C from the three electrolyte inlets 180 is guided by the protrusions 125, 135, and 145, and tends to flow from the side surface of the separator 113 toward the inside.

[0055] <Chemical conversion process> Finally, the bipolar lead-acid battery 100 is obtained by forming the battery under predetermined conditions.

[0056] [Action, effect] As described above, the bipolar lead-acid battery 100 of the embodiment has the convex portions 125, 135, 145 on the inner surfaces of the four side plates of the main body 101, so that the electrolyte that has entered the cell C from the liquid filling port 180 is easily guided by the convex portions 125, 135, 145 and flows from the side surface of the separator 113 to the inside. In particular, as shown by the two-dot chain line in Fig. 4, the electrolyte also easily flows from the side surface of the separator 113 to the inside in the Y direction due to the convex portion 125 formed on the inner surface of the side plate (the side plate formed by the second side plate portions 122b, 132b, 142b and the side plate formed by the fourth side plate portions 122d, 132d, 142d) adjacent to the side plate (the side plate formed by the first side plate portions 122a, 132a, 142a) in which the liquid filling port 180 is formed. If the protrusions 125, 135, and 145 are not provided, such an effect is not exerted.

[0057] Therefore, according to the bipolar lead-acid battery 100 of the embodiment, the separator 113 in the compressed state is more easily impregnated with the electrolyte than when the separator 113 does not have the protrusions 125, 135, 145. As a result, the time required for the electrolyte injection step can be shortened.

[0058] 〔others〕 In the bipolar lead-acid battery 100 of the embodiment, the convex parts 125, 135, 145 facing the side surface of the cell member 110 are formed on the inner surface facing the cell member 110 in all of the four side plates of the body 101, but it is sufficient that the convex parts are formed on the inner surface of at least the side plate (the second side plate portion 122b and the fourth side plate portion 122d in FIG. 4) adjacent to the side plate on which the liquid filling port is formed, among the multiple side plates of the body. In addition, the number of liquid filling ports 180 for each of the multiple cells C is not limited to "three per cell C", and it is sufficient that there is at least one per cell.

[0059] In this embodiment, vibration welding is used as a method for joining the frame body, and convex portions 125, 135, and 145 are formed by a method that creates burrs (melt allowances during welding) on ​​the inner surface of the frame body near the joining surface during vibration welding. However, if a joining method that does not create burrs (e.g., laser welding) is used, convex portions 125, 135, and 145 can be provided in advance on the inner surface of the frame body. In the bipolar lead-acid battery 100 of this embodiment, the tips of the protrusions 125, 135, 145 are in contact with the side surface of the cell member 110, but they do not have to be in contact. The distance between the tips of the protrusions 125, 135, 145 and the side surface of the cell member 110 is preferably 3.0 mm or less, and more preferably 1.0 mm or less. In addition, the protrusions 125, 135, 145 extend perpendicularly from the inner surface of the side plate to the side surface of the separator 113, but may extend at an angle deviated from the perpendicular toward the vicinity of the boundary between the separator 113 and the positive electrode active material layer 111b or the negative electrode active material layer 112b.

[0060] In the bipolar lead-acid battery 100 of this embodiment, the stripe-like protrusions 125, 135, 145 are formed continuously along the X direction and the Y direction on the inner surfaces of the frame bodies 122, 132, 142, respectively, but may be formed intermittently. The interval between the protrusions formed intermittently along the same direction is preferably 60.0 mm or less, and more preferably 30.0 mm or less.

[0061] When the protrusions are formed in the form of continuous or discontinuous stripes, the protruding dimension of the protrusions may be the same or may vary in the direction along the stripes (the direction in which the stripes extend). In this embodiment, a bipolar lead-acid battery using lead for the current collecting plate has been described as an example of a bipolar storage battery. However, the bipolar storage battery of the present invention may be a bipolar storage battery using a metal other than lead for the current collecting plate. [Explanation of symbols]

[0062] 100 Bipolar lead-acid battery (bipolar battery) 101 Main unit 110 Cell member 111 Positive electrode 112 Negative electrode 111a Lead foil for positive electrode 112a Lead foil for negative electrode 111b Active material layer for positive electrode 112b Active material layer for negative electrode 113 Separator 120 Biplate (space forming member) 121 Biplate substrate 121a PCB via hole 121b First recess of substrate 121c Second recess of substrate 122 Biplate frame 122a: a first side plate portion of a frame body constituting a side plate 122b A second side plate portion of a frame body constituting a side plate 122c: A third side plate portion of a frame body constituting a side plate 122d Fourth side plate portion of the frame constituting the side plate 130 First end plate (space forming member) 131 First end plate substrate 132 First end plate frame 132a: a first side plate portion of a frame constituting a side plate 132b A second side plate portion of the frame constituting the side plate 132c: A third side plate portion of a frame body constituting a side plate 132d Fourth side plate portion of the frame constituting the side plate 140 Second end plate (space forming member) 141 Second end plate substrate 142 Second end plate frame 142a: First side plate portion of the frame constituting the side plate 142b: A second side plate portion of a frame body constituting a side plate 142c: A third side plate portion of a frame body constituting a side plate 150 Adhesive layer 160 Conductor 180 Filling port 181 A pair of recesses forming a liquid inlet 190 Lid 191 Electrolyte supply port 125,135,145 Convex C Cell (space for accommodating cell components)

Claims

1. a plurality of cell members each including a positive electrode having a positive electrode active material layer, a negative electrode having a negative electrode active material layer, and a separator interposed between the positive electrode and the negative electrode, the cell members being stacked and arranged with a gap therebetween; A plurality of space forming members that form a plurality of spaces that individually accommodate the plurality of cell members; having The space forming member includes a substrate that covers at least one of the positive electrode side and the negative electrode side of the cell member, and a frame that surrounds a side surface of the cell member, The cell members and the substrates of the space forming members are arranged in an alternately stacked state, the plurality of cell members are electrically connected in series; The opposing surfaces of the adjacent frame bodies are joined together to form a main body, The main body has a plurality of side plates formed by side plate portions of a plurality of the frame bodies, At least one of the side plates is formed with a liquid injection port for each of the spaces; a bipolar storage battery having a protrusion on an inner surface of the side plate facing the cell member;

2. 2. The bipolar storage battery according to claim 1, wherein the protrusion is formed on an inner surface of at least one of the side plates adjacent to the side plate in which the liquid pouring hole is formed.

3. 2. The bipolar storage battery according to claim 1, wherein the tips of said projections are in contact with said cell members.

4. 2. The bipolar storage battery according to claim 1, wherein the protrusion is formed in a continuous stripe shape.

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