JP7057461B1 - Bipolar storage battery, manufacturing method of bipolar storage battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrolytic solution with a current collector plate in a bipolar storage battery in which a positive electrode current collector plate and a negative electrode current collector plate are conducted through a through hole of a substrate and a plurality of cell members are electrically connected in series. Even if it is moved between the board and the board, it is difficult to reach the through hole of the board to prevent a short circuit. At least one of a surface of a substrate (main substrate) 121 arranged between cell members 110 on the side of a positive electrode 111 (bottom surface of a recess 121b) and a surface on the side of a negative electrode 112 (bottom surface of a recess 121c) , The ten-point average roughness (RzJIS) according to the provisions of "JIS B 0601: 2013 Annex JA" is 30 μm or more and 100 μm or less, and the maximum height roughness (Rz) according to this provision is 120 μm or less. A metal current collector plate 111a for a positive electrode and a metal current collector plate 112a for a negative electrode are fixed to the surface with an adhesive 150. [Selection diagram] Fig. 1

Description

The present invention relates to a bipolar storage battery and a method for manufacturing the same.

In recent years, the number of power generation facilities that use natural energy such as solar power and wind power has increased. In such a power generation facility, since the amount of power generation cannot be controlled, a storage battery is used to equalize the power load. That is, when the amount of power generation is larger than the consumption amount, the difference is charged to the storage battery, while when the amount of power generation is smaller than the consumption amount, the difference is discharged from the storage battery. As the above-mentioned storage battery, a lead storage battery is often used from the viewpoint of economy, safety and the like. As such a conventional lead-acid battery, for example, the bipolar lead-acid battery described in Patent Document 1 below is known.

This bipolar lead-acid battery has a frame shape and a resin substrate is attached to the inside of a resin frame. Lead layers are arranged on both sides of the substrate. The lead layer on one surface of the substrate is adjacent to the active material layer for the positive electrode, and the lead layer on the other surface is adjacent to the active material layer for the negative electrode. Further, it has a frame-shaped and resin spacer, and a glass mat impregnated with an electrolytic solution is arranged inside the spacer. Then, a plurality of frames and spacers are alternately laminated, and the frames and spacers are bonded with an adhesive or the like. Further, the lead layers on both sides of the substrate are connected via the through holes provided in the substrate.

That is, the bipolar lead 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 positive electrode and a negative electrode. A plurality of cell members, which are provided with a separator (glass mat) interposed between the two cells and are arranged in a laminated manner at intervals, and a plurality of space forming members for individually accommodating a plurality of cell members. , And both the positive electrode current collector plate and the negative electrode current collector plate are made of metal (lead). Further, 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 body (a frame portion and a spacer of a bipolar plate and an end plate) that surrounds the side surface of the cell member. I'm out. Further, the substrate of the cell member and the substrate of the space forming member are alternately arranged in a laminated state, and the substrate arranged between the adjacent cell members has a through hole extending in a direction intersecting the plate surface, and the through hole is formed. Among them, the positive electrode current collector plate and the negative electrode current collector plate of the adjacent cell members are electrically connected to each other in series, and the adjacent frame bodies are joined.

However, Patent Document 1 describes that the lead foil, which is a positive electrode current collector plate and a negative electrode current collector plate, is described as "the lead foil is arranged in the material receiving passage of the frame on both exposed surfaces of the substrate". There is no description that the lead foil is fixed to the substrate with an adhesive, and there is no description that suggests it.

Japanese Patent No. 6124894

As described above, in the case of a bipolar storage battery in which a positive electrode current collector plate and a negative electrode current collector plate are conducted through a through hole in the substrate and a plurality of cell members are electrically connected in series, the current collector plate is used. When the electrolytic solution existing in the active material layer moves between the substrate and the current collector due to corrosion, the electrolytic solution reaches the collector plate on the opposite side via the through hole, and a liquid entanglement phenomenon occurs. May occur and lead to a short circuit. This liquid entanglement phenomenon occurs even when the current collector plate is fixed to the substrate with an adhesive, but if there is a part where the adhesive layer does not exist, the electrolytic solution moves between the current collector plate and the substrate. It can lead to through holes.

An object of the present invention is to collect an electrolytic solution in a bipolar storage battery in which a positive electrode current collector plate and a negative electrode current collector plate are conducted through a through hole in a substrate and a plurality of cell members are electrically connected in series. Even if it moves between the electric plate and the substrate, it is difficult to reach the through hole to prevent a short circuit.

The first aspect of the present invention for solving the above-mentioned problems is a bipolar storage battery having the following configurations (1) to (4).
(1) 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 interposed between the positive electrode and the negative electrode are provided at intervals. It has a plurality of cell members arranged in a laminated manner by opening the cells, and a plurality of space forming members for forming a plurality of spaces individually accommodating the plurality of cell members.
(2) The space forming member includes a synthetic resin substrate that covers both the positive electrode side and the negative electrode side of the cell member, and a frame that surrounds the side surface of the cell member. The cell member and the substrate of the space forming member are arranged in a state of being alternately laminated. The adjacent frames are joined together.
(3) At least one of the surface on the positive electrode side and the surface on the negative electrode side of the main substrate, which is the substrate arranged between the adjacent cell members, is "JIS B 0601: 2013 Annex JA". The ten-point average roughness (RzJIS) according to the above-mentioned regulation is 30 μm or more and 100 μm or less, and the maximum height roughness (Rz) according to the above-mentioned regulation is 120 μm or less.
(4) The metal current collector plate for the positive electrode is fixed to the surface of the main substrate, which is the substrate arranged between the adjacent cell members, on the side of the positive electrode with an adhesive. The metal current collector plate for the negative electrode is fixed to the surface of the main substrate on the side of the negative electrode with an adhesive. The main substrate has a through hole extending in a direction intersecting the plate surface, and in the through hole, the positive electrode current collector plate and the negative electrode current collector plate of the adjacent cell member are conducted to conduct electricity. The plurality of cell members are electrically connected in series.

The second aspect of the present invention is a method for manufacturing a bipolar storage battery having the above configurations (1), (2) and (4), and has the following configuration (5).
(5) As the main substrate, at least one of the surface on the positive electrode side and the surface on the negative electrode side of the main substrate has a ten-point average roughness according to the provisions of "Appendix JA of JIS B 0601: 2013" ( RzJIS) is 30 μm or more and 100 μm or less, and the maximum height roughness (Rz) according to the above specification is 120 μm or less.

The bipolar storage battery of the present invention and the bipolar storage battery obtained by the method of the present invention are less likely to reach through holes even when the electrolytic solution moves between the current collector plate and the substrate, and a short-circuit prevention effect can be obtained. Can be expected to be done.

It is sectional drawing which shows the schematic structure of the bipolar lead-acid battery which is one Embodiment of this invention. It is a partially enlarged view of the bipolar lead-acid battery of FIG.

Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the embodiments shown below. In the embodiments shown below, technically preferable limitations are made 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 the bipolar lead-acid battery.

〔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 includes a plurality of cell members 110, a plurality of biplates (space forming members) 120, and a first end plate (space forming member) 130. , Has a second end plate (space forming member) 140. FIG. 1 shows a bipolar lead-acid battery 100 in which three cell members 110 are stacked, but the number of cell members 110 is determined by the battery design. Further, the number of bi-plates 120 is determined according to the number of cell members 110.

The stacking direction of the cell members 110 is the Z direction (vertical direction in FIGS. 1 and 2), and the direction perpendicular to the Z direction is the X 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 electrolytic solution. The positive electrode 111 has lead foils for positive electrodes (current collector plates for positive electrodes) 111a and 111aa and an active material layer 111b for positive electrodes. The negative electrode 112 has a lead foil for the negative electrode (current collector plate for the negative electrode) 112a, 112aa and an active material layer 112b for the negative electrode. The separator 113 is interposed between the positive electrode 111 and the negative electrode 112. In the cell member 110, the lead foils 111a and 111aa for the positive electrode, the active material layer 111b for the positive electrode, the separator 113, the active material layer 112b for the negative electrode, and the lead foils 112a and 112aa for the negative electrode are laminated in this order.

The dimension (thickness) in the Z direction of the positive electrode lead foil 111a is larger (thicker) than that of the negative electrode lead foil 112a, and the positive electrode active material layer 111b is larger (thicker) than the negative electrode active material layer 112b.
The plurality of cell members 110 are stacked and arranged at intervals in the Z direction, and the substrate 121 of the biplate 120 is arranged at the portions of the intervals. That is, the plurality of cell members 110 are laminated with the substrate 121 of the biplate 120 sandwiched between them.

The plurality of bi-plates 120, the first end plate 130, and the second end plate 140 are members for forming a plurality of spaces (cells) C that individually accommodate the plurality of cell members 110.
As shown in FIG. 2, the biplate 120 includes a substrate 121 having a rectangular planar shape, a frame body 122 covering the four end faces of the substrate 121, and a pillar portion 123 vertically protruding from both sides of the substrate 121. The substrate 121, the frame body 122, and the pillar portion 123 are integrally formed of synthetic resin. The number of pillars 123 protruding from each surface of the substrate 121 may be one or a plurality.

In the Z direction, the dimension of the frame 122 is larger than the dimension (thickness) of the substrate 121, and the dimension between the protruding end faces of the pillar 123 is the same as the dimension of the frame 122. Then, a space C is formed between the substrate 121 and the substrate 121 by contacting and stacking the frame body 122 and the pillar portions 123 with each other, and the pillar portions 123 in contact with each other form a space. The dimension of C in the Z direction is retained.

The lead foils 111a and 111aa for the positive electrode, the active material layer 111b for the positive electrode, the lead foils 112a and 112aa for the negative electrode, the active material layer 112b for the negative electrode, and the separator 113 have through holes 111c, 111d, 112c through which the pillar portion 123 is penetrated. 112d and 113a are formed, respectively.
The substrate (main substrate) 121 of the biplate 120 has a plurality of through holes 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 depth of the first recess 121b is deeper than that of the second recess 121c. The dimensions of the first recess 121b and the second recess 121c in the X and Y directions correspond to the dimensions of the lead foil 111a for the positive electrode and the lead foil 112a for the negative electrode in the X and Y directions.

Further, the bottom surface of the first recess 121b (the surface of the substrate 121 on the positive electrode 111 side) and the bottom surface of the second recess 121c (the surface of the substrate 121 on the negative electrode 112 side) are described in "JIS B 0601: 2013 Annex". The ten-point average roughness (RzJIS) according to the provisions of "JA" is 30 μm or more and 100 μm or less, and the maximum height roughness (Rz) according to this provision is 120 μm or less.

The substrate 121 of the biplate 120 is arranged between 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. In the first recess 121b of the substrate 121 of the biplate 120, the lead foil 111a for the positive electrode of the cell member 110 is arranged via the adhesive layer 150. That is, the lead foil 111a for the positive electrode is fixed to the surface of the substrate 121 on the side of the positive electrode 111 (the bottom surface of the first recess 121b) with an adhesive.

Further, the lead foil 112a for the negative electrode of the cell member 110 is arranged in the second recess 121c of the substrate 121 of the biplate 120 via the adhesive layer 150. That is, the lead foil 112a for the negative electrode is fixed to the surface of the substrate 121 on the side of the negative electrode 112 (the bottom surface of the second recess 121c) with an adhesive.
The conductor 160 is arranged in the through hole 121a of the substrate 121 of the biplate 120, and both end faces of the conductor 160 are in contact with and bonded to the lead foil 111a for the positive electrode and the lead foil 112a for the negative electrode. That is, the lead foil 111a for the positive electrode and the lead foil 112a for the negative electrode are electrically connected by the conductor 160. As a result, all of the plurality of cell members 110 are electrically connected in series.

As shown in FIG. 1, the first end plate 130 is arranged on a substrate 131 that covers the positive electrode side of the cell member 110, a frame 132 that surrounds the side surface of the cell member 110, and one surface of the substrate 131 (most positive electrode side). It is composed of a pillar portion 133 that projects vertically from the surface of the biplate 120 facing the substrate 121). The planar shape of the substrate 131 is rectangular, the four end faces of the substrate 131 are covered with the frame 132, and the substrate 131, the frame 132, and the pillar 133 are integrally formed of synthetic resin. The number of the pillars 133 protruding from one surface of the substrate 131 may be one or a plurality, but the number of the pillars 133 may correspond to the pillars 123 of the biplate 120 in contact with the pillars 133.

In the Z direction, the dimension of the frame 132 is larger than the dimension (thickness) of the substrate 131, and the dimension between the protruding end faces of the column 133 is the same as the dimension of the frame 132. Then, the frame 132 and the pillar 133 are brought into contact with each other and laminated with respect to the frame 122 and the pillar 123 of the bi-plate 120 arranged on the outermost side (positive side), so that the substrate 121 of the bi-plate 120 is laminated. Space C is formed between the substrate 131 of the first end plate 130, and the Z-direction dimension of the space C is formed by the pillar portion 123 of the bi-plate 120 and the pillar portion 133 of the first end plate 130 that are in contact with each other. Is retained.

Through holes 111c, 111d, 113a through which the pillar portion 133 is penetrated are formed in the lead foil 111aa for the positive electrode, the active material layer 111b for the positive electrode, and the separator 113 of the cell member 110 arranged on the outermost side (positive electrode side), respectively. ing.
A recess 131b is formed on one surface of the substrate 131 of the first end plate 130. The dimension of the recess 131b in the X direction corresponds to the dimension of the lead foil 111aa for the positive electrode in the X direction. The Z-direction dimension of the positive electrode lead foil 111aa arranged on one surface of the substrate 131 of the first end plate 130 is larger than the Z-direction dimension of the positive electrode lead foil 111a arranged on one surface of the substrate 121 of the bi-plate 120. Is also big.

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

The second end plate 140 includes a substrate 141 that covers the negative electrode side of the cell member 110, a frame 142 that surrounds the side surface of the cell member 110, and one surface of the substrate 141 (the substrate 121 of the biplate 120 that is arranged on the most negative electrode side). It is composed of a pillar portion 143 that projects vertically from the surface facing the surface). The planar shape of the substrate 141 is rectangular, the four end faces of the substrate 141 are covered with the frame body 142, and the substrate 141, the frame body 142, and the pillar portion 143 are integrally formed of synthetic resin. The number of pillars 143 protruding from one surface of the substrate 141 may be one or a plurality, but the number of pillars 143 may correspond to the pillars 123 of the biplate 120 in contact with the pillars 143.

In the Z direction, the dimension of the frame 142 is larger than the dimension (thickness) of the substrate 131, and the dimension between the protruding end faces of the two pillars 143 is the same as the dimension of the frame 142. Then, the frame body 142 and the pillar portion 143 are brought into contact with the frame body 122 and the pillar portion 123 of the bi-plate 120 arranged on the outermost side (negative side), and the frame body 142 and the pillar portion 143 are brought into contact with each other and laminated to form the substrate 121 of the bi-plate 120. Space C is formed between the substrate 141 of the second end plate 140, and the Z-direction dimension of the space C is formed by the pillar portion 123 of the bi-plate 120 and the pillar portion 143 of the second end plate 140 that are in contact with each other. Is retained.

Through holes 112c, 112d, 113a through which the pillar portion 143 is penetrated are formed in the lead foil 112aa for the negative electrode, the active material layer 112b for the negative electrode, and the separator 113 of the cell member 110 arranged on the outermost side (negative electrode side), respectively. ing.
A recess 141b is formed on one surface of the substrate 141 of the second end plate 140. The dimensions of the recess 141b in the X and Y directions correspond to the dimensions of the lead foil 112aa for the negative electrode in the X and Y directions. The Z-direction dimension of the negative electrode lead foil 112aa arranged on one surface of the substrate 141 of the second end plate 140 is the Z-direction dimension of the negative electrode lead foil 112a arranged on the other surface of the substrate 121 of the bi-plate 120. Greater than.

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

As can be seen from the above description, the biplate 120 is a space forming member including a substrate 121 that covers both the positive electrode side and the negative electrode side of the cell member 110 and a frame body 122 that surrounds the side surface of the cell member 110. .. The first end plate 130 is a space forming member including a substrate 131 that covers only the positive electrode side (one of the positive electrode side and the negative electrode side) of the cell member 110, and a frame 132 that surrounds the side surface of the cell member 110.

Further, 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 body 142 that surrounds the side surface of the cell member 110. be. That is, the substrates 121, 131, 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. be. Further, the substrate 121 of the bi-plate 120 is a substrate (main substrate) arranged between the cell members 110.

[Action, effect]
In the bipolar lead-acid battery 100 of the embodiment, both the bottom surface of the recess 121b of the substrate 121, which is the main substrate (the surface on the side of the positive electrode 111 of the substrate 121) and the bottom surface of the recess 121c (the surface on the side of the negative electrode 112 of the substrate 121). However, the ten-point average roughness (RzJIS) according to the provisions of "JIS B 0601: 2013 Annex JA" is 30 μm or more and 100 μm or less, and the maximum height roughness (Rz) according to this provision is 120 μm or less. .. Then, the lead foil 111a for the positive electrode is fixed to the surface of the substrate 121 on the side of the positive electrode 111 (bottom surface of the recess 121b) with an adhesive, and the negative electrode is applied to the surface of the substrate 121 on the side of the negative electrode 112 (bottom surface of the recess 121c). The lead foil 112a is fixed. As a result, the bipolar lead-acid battery 100 can obtain the following actions and effects.

When the positive electrode lead foil 111a is corroded, the electrolytic solution existing in the positive electrode active material layer 111b tends to move toward the substrate 121 through the corroded portion of the positive electrode lead foil 111a, but the positive electrode lead foil 111a is present. Since it is fixed to the bottom surface of the recess 121b of the substrate 121 with an adhesive, the presence of the adhesive layer 150 suppresses the electrolytic solution from reaching the bottom surface of the recess 121b of the substrate 121.

Further, even when this electrolytic solution reaches the bottom surface of the recess 121b of the substrate 121, the rougher the surface condition of the bottom surface of the recess 121b (the larger the value of RZjis and Rz) is, the smoother the surface is (the value of RZjis and Rz is higher). The distance that the electrolytic solution reaching the bottom surface moves to the through hole 121a of the substrate 121 is longer than that (when it is small). Therefore, the electrolytic solution that has reached the bottom surface is less likely to reach the through hole 121a, and the occurrence of the liquid entanglement phenomenon is suppressed, so that the effect of preventing a short circuit of the bipolar lead-acid battery 100 can be expected.

On the other hand, if the surface condition of the bottom surfaces of the first recess 121b and the second recess 121c is too rough, the amount of adhesive required to fix the lead foil 111a for the positive electrode and the lead foil 111b for the negative electrode having the same flat area will be increased. In addition to increasing the cost, if an attempt is made to bond with a predetermined amount of adhesive, there arises a problem that the adhesive strength in the planes of the lead foil 111a for the positive electrode and the lead foil 111b for the negative electrode becomes non-uniform. .. In the bipolar lead-acid battery 100, the surface condition of the bottom surface of the first recess 121b and the second recess 121c satisfies "RzJIS is 30 μm or more and 100 μm or less, and Rz is 120 μm or less". It can be expected to solve various problems.

It should be noted that the bottom surfaces of the first recess 121b and the second recess 121c (the surface on the positive electrode side of the main substrate) are compatible with the effect of suppressing liquid entanglement and the effect of obtaining the required adhesive strength with a small amount of adhesive. And / or the surface state on the negative electrode side) preferably satisfies "RzJIS is 50 μm to 75 μm and Rz is 20 μm to 90 μm".

Further, as a method for setting the surface state of the surface on the positive electrode side and / or the surface on the negative electrode side of the main substrate to "RzJIS of 30 μm or more and 100 μm or less and Rz of 120 μm or less", after molding with synthetic resin. Examples thereof include a method of rubbing the surface of the main substrate with sandpaper, a method of applying grain processing to the surface of the main substrate, and a method of applying a surface treatment such as sandblasting or shot blasting to the surface of the main substrate. Alternatively, when the main substrate is molded from synthetic resin, the surface of the mold is roughened so that the surface state of the positive electrode side surface and / or the negative electrode side surface is "RzJIS is 30 μm or more and 100 μm or less, and Rz is There is also a method of making it 120 μm or less.

Further, in the above embodiment, a bipolar lead-acid battery in which the positive electrode collector plate is made of a positive electrode lead foil and the negative electrode current collector plate is made of a negative electrode lead foil has been described. However, one aspect of the present invention is for a positive electrode. It can also be applied to a bipolar storage battery in which the current collector plate and the current collector plate for the negative electrode are made of a metal other than lead (for example, aluminum, copper, nickel), an alloy, or a conductive resin.

[Preparation of bi-plate, current collector plate for positive electrode, and current collector plate for negative electrode]
[Cut out each current collector plate]
A rolled sheet having a tin (Sn) content of 1.0% by mass, a balance of lead (Pb) and a lead alloy which is an unavoidable impurity, and a thickness of 0.30 mm is 28 cm on a side. It was cut into a square sheet and used as a positive current collector plate 111a for the biplate 120 of samples No. 1 to No. 8. Further, a rolled sheet made of the same lead alloy and having a thickness of 1.50 mm is cut into a square sheet having a side of 28 cm, and the positive electrode for the first end plate 130 of the samples No. 1 to No. 8 is obtained. The current collector plate 111aa was used.

A rolled sheet having a tin (Sn) content of 1.0% by mass, a balance of lead (Pb) and a lead alloy which is an unavoidable impurity, and a thickness of 0.1 mm is 28 cm on a side. It was cut into a square sheet and used as a negative current collector plate 112a for the biplate 120 of samples No. 1 to No. 8. Further, a rolled sheet made of the same lead alloy and having a thickness of 1.50 mm is cut into a square sheet having a side of 28 cm, and the negative electrode for the second end plate 140 of the samples No. 1 to No. 8 is obtained. The current collector plate 112aa was used.

[Making a bi-plate]
<Sample No.1>
By injection molding of ABS resin, a biplate 120 having the shape shown in FIG. 1 was produced. The thickness of the substrate 121 of the biplate 120 is 2 mm. The bottom surface of the recess 121b is a square with a side of 28.5 cm and a depth of 0.32 mm. The bottom surface of the recess 121c is a square with a side of 28.5 cm and a depth of 0.12 mm.
When the surface condition of the bottom surface of the recess 121b of the substrate 121 of the biplate 120 was measured based on the provisions of "JIS B 0601: 2013 Annex JA", the ten-point average roughness (RzJIS) was 10 μm, which was the maximum height. The roughness (Rz) was 17 μm.

<Sample No.2>
The bottom surface of the recess 121b and the recess 121c of the biplate 120 manufactured by the same method as sample No. 1 was rubbed with sandpaper No. 2000, and the ten-point average roughness (RzJIS) was 18 μm, and the maximum height roughness ( Rz) was set to 23 μm. This was used as the sample No. 2 biplate.

<Sample No.3>
The bottom surface of the recess 121b and the recess 121c of the biplate 120 manufactured by the same method as sample No. 1 was rubbed with sandpaper No. 800, and the ten-point average roughness (RzJIS) was 30 μm, and the maximum height roughness ( Rz) was set to 39 μm. This was used as the sample No. 3 biplate.

<Sample No.4>
The bottom surface of the recess 121b and the recess 121c of the biplate 120 manufactured by the same method as sample No. 1 was rubbed with sandpaper No. 800, and the ten-point average roughness (RzJIS) was 46 μm, and the maximum height roughness ( Rz) was set to 63 μm. This was used as the sample No. 4 biplate.

<Sample No.5>
By embossing the bottom surfaces of the recesses 121b and 121c of the biplate 120 manufactured by the same method as sample No. 1, the ten-point average roughness (RzJIS) is 69 μm and the maximum height roughness (Rz) is It was set to 155 μm. This was used as the sample No. 5 biplate.

<Sample No.6>
The bottom surface of the recess 121b and the recess 121c of the biplate 120 manufactured by the same method as sample No. 1 was rubbed with sandpaper No. 150, and the ten-point average roughness (RzJIS) was 77 μm, and the maximum height roughness ( Rz) was set to 92 μm. This was used as the sample No. 6 biplate.

<Sample No.7>
The bottom surface of the recess 121b and the recess 121c of the biplate 120 manufactured by the same method as sample No. 1 was rubbed with sandpaper No. 120, and the ten-point average roughness (RzJIS) was 104 μm, and the maximum height roughness ( Rz) was set to 123 μm. This was used as the sample No. 7 biplate.

<Sample No.8>
The bottom surface of the recess 121b and the recess 121c of the biplate 120 manufactured by the same method as sample No. 1 was rubbed with sandpaper No. 80, and the ten-point average roughness (RzJIS) was 128 μm, and the maximum height roughness ( Rz) was adjusted to 141 μm. This was used as the sample No. 8 biplate.

[Making end plate]
<Sample No.1 to No.8>
The first end plate 130 and the second end plate 140 having the shapes shown in FIG. 1 were produced by injection molding of ABS resin. The thickness of the substrate 131 of the first end plate 130 and 141 of the second end plate 140 is 10 mm. The bottom surfaces of the recess 131b and the recess 141b are squares with a side of 28.5 cm and a depth of 1.52 mm.

[Assembly of bipolar lead-acid battery]
All of them have the same structure as shown in FIG. 1 except that each of the samples No. 1 to No. 8 biplates is used, and the No. 1 to No. 8 bipolar type has a rated capacity of 45 Ah. I assembled a lead-acid battery. That is, all the samples had the same configuration except for the surface condition of the bottom surface of the recess 121b of the substrate 121 of the biplate 120.

The positive electrode active material layer 111b and the negative electrode active material layer 112b were made of a lead compound, and the separator 113 was made of glass fiber, each having a thickness corresponding to a rated capacity of 45 Ah.

[Life test]
First, each of the No. 1 to No. 8 bipolar lead-acid batteries is placed in a water tank whose water temperature is controlled to 25 ° C ± 2 ° C, and the rated capacity is until the terminal voltage of the battery drops to 1.8 V / cell. The battery was discharged at a 10-hour rate current (4.5 A) of (45 Ah), the discharge duration was recorded, and the 10-hour rate capacity was calculated from the discharge current and the discharge duration.

Next, after each bipolar lead-acid battery was fully charged, the following (1) was repeated 400 times while constantly measuring the terminal voltage.
(1) Discharge for 7 hours at a 10-hour rate current (4.5 A) with a rated capacity (45 Ah). That is, DOD 70% is discharged with respect to the rated capacity.
When a liquid entanglement occurs, the terminal voltage drops sharply. Whether or not liquid entanglement has occurred is determined by whether or not each battery after repeating the above discharge 400 times is disassembled and the peripheral edge of the joint portion of the lead foil 111a for the positive electrode with the conductor 160 is discolored by sulfuric acid. It was done by confirming. Then, the presence or absence of liquid entanglement was determined from the degree of discoloration.

[Adhesive application test]
First, as a test plate corresponding to each of the bi-plates 120 of Samples No. 1 to No. 8, the surface condition of one surface of a square plate made of ABS resin, having a thickness of 2 mm and a side of 30 cm, is shown as a sample No. We prepared the ones having the same surface condition as the bottom surface of the recesses 121b and the recesses 121c of each of the biplates 120 of .1 to No. 8.

Next, 25 ml of the adhesive is applied to one surface of the test plate for each sample. At that time, the substrate surface is held horizontally. After that, a square lead alloy sheet having a side of 28 cm is placed on the surface coated with the adhesive, and a rubber roller is applied to the upper surface of the sheet so as to go from the end (right end) to the end (left end). By moving to, attach the sheet while spreading the adhesive.
Next, it was examined whether the adhesive spreads on the entire surface without any gaps. As the adhesive, an epoxy adhesive "Epiform (registered trademark) K-9487" manufactured by SOMAR Corporation was used.

Since the ABS resin plate with a thickness of 2 mm has a high transmittance, by visually observing the other surface of the plate (the surface to which the lead alloy sheet is not attached), the adhesive between the plates can be obtained. You can check the status.
When the adhesive spreads on the entire surface without gaps, it was determined that the amount of adhesive was sufficient (◯), and when there were gaps, it was determined that the amount of adhesive was insufficient (×).
These results are shown in Table 1 together with the surface condition of the substrate (bottom surface of the recesses 121b and 121c and one surface of the test plate).

The following can be seen from the results in Table 1.
The surface condition of both sides (the surface on the positive electrode side and the surface on the negative electrode side) of the main substrate 121 is such that the ten-point average roughness (RzJIS) according to the provisions of {JIS B 0601: 2013 Annex JA "is 30 μm or more and 100 μm or less. , The maximum height roughness (Rz) according to this regulation is 120 μm or less}, and the positive electrode current collector plate 111a and the negative electrode current collector plate 112a made of lead alloy are fixed to each surface with an adhesive. , No.4, No.6, and No.7 bipolar lead storage batteries have both the effect of suppressing liquid leakage and the effect of obtaining the required adhesive strength with a small amount of adhesive used.

In the No. 2 and No. 3 bipolar lead-acid batteries having an RzJIS of less than 30 μm, the required adhesive strength was obtained with a small amount of adhesive used, but the liquid squeeze suppressing effect was not obtained. In addition, the No. 5 bipolar lead-acid battery with RzJIS of 69 μm but Rz exceeding 120 μm and the No. 8 bipolar lead-acid battery with RzJIS exceeding 100 μm and Rz exceeding 120 μm suppress liquid leakage. The effect was obtained, but the amount of adhesive for obtaining the required adhesive strength was increased.

100 Bipolar lead-acid battery 110 Cell member 111 Positive electrode 112 Negative electrode 111a Lead electrode for positive electrode (collector plate for positive electrode arranged on the surface of the main substrate on the positive electrode side)
111aa Lead foil for positive electrode (current collector plate for positive electrode)
111b Active material layer for positive electrode 112a Lead foil for negative electrode (current collector plate for negative electrode arranged on the surface of the main substrate on the negative electrode side)
112aa Lead foil for negative electrode (current collector plate for negative electrode)
112b Active material layer for negative electrode 113 Separator 120 Bi-plate 121 Bi-plate substrate (substrate arranged between adjacent cell members, main substrate)
121a Through hole of the substrate 121b First recess of the substrate 121c Second recess of the substrate 122 Bi-plate frame 130 First end plate 131 First end plate substrate 132 First end plate frame 140 No. Second end plate 141 Second end plate substrate 142 Second end plate frame 150 Adhesive layer 160 Conductor C cell (space for accommodating cell members)

Claims (3)

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 interposed between the positive electrode and the negative electrode are provided at intervals. Multiple cell members arranged in layers and
A plurality of space forming members that form a plurality of spaces individually accommodating the plurality of cell members, and a plurality of space forming members.
Have,
The space forming member includes a synthetic resin 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 the side surface of the cell member.
The cell member and the substrate of the space forming member are arranged in a state of being alternately laminated, and the adjacent frames are joined to each other.
At least one of the surface on the positive electrode side and the surface on the negative electrode side of the main substrate, which is the substrate arranged between the adjacent cell members, is in accordance with the provisions of "Appendix JA of JIS B 0601: 2013". The ten-point average roughness (RzJIS) is 30 μm or more and 100 μm or less, and the maximum height roughness (Rz) according to the above specification is 120 μm or less.
The metal current collector plate for the positive electrode is fixed to the surface of the main substrate on the side of the positive electrode with an adhesive.
The metal current collector plate for the negative electrode is fixed to the surface of the main substrate on the negative electrode side with an adhesive.
The main substrate has a through hole extending in a direction intersecting the plate surface, and in the through hole, the positive electrode current collector plate and the negative electrode current collector plate of the adjacent cell member are conducted to conduct electricity. A bipolar storage battery in which the plurality of cell members are electrically connected in series. The bipolar storage battery according to claim 1, wherein the positive electrode current collector plate and the negative electrode current collector plate are made of lead or a lead alloy. It is a manufacturing method of bipolar storage battery.
The bipolar storage battery is
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 interposed between the positive electrode and the negative electrode are provided at intervals. Multiple cell members arranged in layers and
A plurality of space forming members that form a plurality of spaces individually accommodating the plurality of cell members, and a plurality of space forming members.
Have,
The space forming member includes a synthetic resin 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 the side surface of the cell member.
The cell member and the substrate of the space forming member are arranged in a state of being alternately laminated, and the adjacent frames are joined to each other.
The metal current collector plate for the positive electrode is fixed to the surface of the main substrate, which is the substrate arranged between the adjacent cell members, on the side of the positive electrode with an adhesive.
The metal current collector plate for the negative electrode is fixed to the surface of the main substrate on the negative electrode side with an adhesive.
The main substrate has a through hole extending in a direction intersecting the plate surface, and in the through hole, the positive electrode current collector plate and the negative electrode current collector plate of the adjacent cell member are conducted to conduct electricity. The plurality of cell members are electrically connected in series, and the plurality of cell members are electrically connected in series.
As the main board
At least one of the surface on the positive electrode side and the surface on the negative electrode side of the main substrate has a ten-point average roughness (RzJIS) of 30 μm or more and 100 μm or less according to the provisions of “JIS B 0601: 2013 Annex JA”. A method for manufacturing a bipolar storage battery using a battery having a maximum height roughness (Rz) of 120 μm or less according to the above specifications.

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