WO2021059629A1

WO2021059629A1 - Active material holding member, electrode, lead acid storage battery, and electric car

Info

Publication number: WO2021059629A1
Application number: PCT/JP2020/024413
Authority: WO
Inventors: 啓太鈴木
Original assignee: 昭和電工マテリアルズ株式会社
Priority date: 2019-09-27
Filing date: 2020-06-22
Publication date: 2021-04-01
Also published as: WO2021059533A1; JPWO2021059629A1; CN114868285A

Abstract

A lead acid storage battery 100 according to the present invention is provided with a positive electrode 10 that comprises: an active material holding member 50 which is provided with a tube 52 that holds an active material; and an active material which is held by the tube 52. With respect to the active material holding member 50, the tube 52 has one end part 52a, the other end part 52b, and an intermediate part 52c that is positioned between the one end part 52a and the other end part 52b. This lead acid storage battery 100 has an embodiment wherein the compressive strength of the one end part 52a is higher than the compressive strength of the intermediate part 52c, or an embodiment wherein the compressive strength of the one end part 52a of the tube 52 is not less than 3 N/mm².

Description

Active material holding members, electrodes, lead-acid batteries and electric vehicles

The present invention relates to an active material holding member, an electrode, a lead storage battery, and an electric vehicle.

Lead-acid batteries are widely used as secondary batteries for industrial or consumer use, and in particular, lead-acid batteries for electric vehicles (for example, lead-acid batteries for automobiles, so-called batteries), UPS (Uninterruptable Power Supply), and disaster prevention (emergency). ) There is a great demand for lead-acid batteries for backup such as wireless power supplies and telephone power supplies.

In lead-acid batteries, an active material holding member having a tube capable of holding (accommodating) the active material may be used. For example, a lead-acid battery has an active material holding member provided with a tube, a core metal (current collector) inserted in the tube, and an electrode material (electrode material containing an active material) filled between the tube and the core metal. ) Is provided (see, for example, Patent Document 1 below).

Japanese Unexamined Patent Publication No. 8-203506

By the way, in the case of manufacturing an electrode having an active material holding member, when lead powder (raw material of active material), core metal, etc. is supplied to the inside of the tube from the end of the tube, the lead powder, core metal, etc. are applied to the end of the tube. Contact with the portion may deform the end of the tube and damage the tube. Further, in order to seal the end of the tube, a sealing member may be attached to the end of the tube, and the stress applied by the sealing member deforms the end of the tube and damages the tube. It may end up.

One aspect of the present invention is to provide an active material holding member capable of suppressing breakage of a tube. Another aspect of the present invention is to provide an electrode having the active material holding member, a lead storage battery provided with the electrode, and an electric vehicle provided with the lead storage battery.

A first embodiment of one aspect of the present invention is an active material holding member including a tube for holding the active material, wherein the tube is one end portion, the other end portion, the one end portion, and the other end portion. Provided is an active material holding member having an intermediate portion between the two, and the compressive strength of the one end portion is higher than the compressive strength of the intermediate portion.

In such an active material holding member, since the compressive strength of one end of the tube is relatively high with respect to the intermediate portion of the tube, when lead powder, core metal, etc. are supplied from the one end, the one end of the tube is Deformation is suppressed, and deformation of the one end of the tube due to stress applied by the sealing member attached to the one end is suppressed. As a result, it is possible to prevent the tube from being damaged.

A second embodiment of one aspect of the present invention is an active material holding member including a tube for holding the active material, wherein the compressive strength of one end of the tube is 3 N / mm ² or more. provide.

In such an active material holding member, since the compressive strength of one end of the tube is high, deformation of the one end of the tube when supplying lead powder, core metal, etc. from the one end is suppressed. , The deformation of the one end of the tube due to the stress applied by the sealing member attached to the one end is suppressed. As a result, it is possible to prevent the tube from being damaged.

Another aspect of the present invention provides an electrode having the above-mentioned active material holding member and the active material held in the tube of the active material holding member.

Another aspect of the present invention provides a lead-acid battery comprising a positive electrode and a negative electrode, wherein at least one selected from the group consisting of the positive electrode and the negative electrode is the above-mentioned electrode.

Another aspect of the present invention provides an electric vehicle equipped with the lead-acid battery described above.

According to one aspect of the present invention, it is possible to provide an active material holding member capable of suppressing breakage of the tube. According to another aspect of the present invention, it is possible to provide an electrode having the active material holding member, a lead storage battery provided with the electrode, and an electric vehicle provided with the lead storage battery.

It is a schematic cross-sectional view which shows the lead-acid battery which concerns on one Embodiment of this invention. It is a schematic cross-sectional view which shows the lead-acid battery which concerns on one Embodiment of this invention.

Hereinafter, a mode for carrying out the present invention will be described in detail. However, the present invention is not limited to the following embodiments.

In the present specification, the numerical range indicated by using "-" indicates a range including the numerical values before and after "-" as the minimum value and the maximum value, respectively. In the numerical range described stepwise in the present specification, the upper limit value or the lower limit value of the numerical range of one step can be arbitrarily combined with the upper limit value or the lower limit value of the numerical range of another step. "A or B" may include either A or B, or both. Unless otherwise specified, the materials exemplified in the present specification may be used alone or in combination of two or more. The term "process" is included in this term not only in an independent process but also in the case where the desired action of the process is achieved even if it cannot be clearly distinguished from other processes. "At least one" means one or more. "At least part" means part or all.

The lead-acid battery according to the present embodiment includes a positive electrode and a negative electrode, and at least one selected from the group consisting of the positive electrode and the negative electrode is the electrode according to the present embodiment. The electrodes according to the present embodiment include the active material holding member according to the present embodiment (including the first embodiment and the second embodiment; the same applies hereinafter) and the active material held in the tube of the active material holding member. And have. The active material may include lead powder. The lead-acid battery according to the present embodiment may include a separator arranged between the positive electrode and the negative electrode, and may not include the separator. The lead storage battery according to the present embodiment may include an electrolytic solution. The electrolytic solution may contain sulfuric acid. The lead-acid battery according to the present embodiment may be a liquid-type lead-acid battery, a control valve-type lead-acid battery, or the like, and may be a closed-type lead-acid battery, an open-type lead-acid battery, or the like.

The active material holding member is a member for holding the active material of the battery, and can hold (accommodate) the active material inside the tube (internal space). The active material holding member may include a plurality of tubes. The "active material" includes both the post-chemical active material and the raw material of the pre-chemical active material.

The active material holding member according to the first embodiment is an active material holding member including a tube for holding the active material, and the tube is intermediate between one end, the other end, and one end and the other end. The compression strength of one end portion is higher than that of the intermediate portion. In such an active material holding member, since the compressive strength of one end of the tube is relatively high with respect to the intermediate portion of the tube, the one end of the tube is subjected to when lead powder, core metal, etc. are supplied from the one end. Deformation is suppressed, and the one end of the tube is deformed by the stress applied by the sealing member attached to the one end (for example, when the sealing member has a base and a protrusion described later). , Deformation of the one end due to contact between one end of the tube and the base, and deformation of the one end due to contact between one end of the tube and the protrusion) are suppressed. As a result, it is possible to prevent the tube from being damaged, and it is possible to obtain excellent electrical characteristics (for example, discharge characteristics).

In the first embodiment, the tube may have a portion having a compression strength higher than the compression strength of the intermediate portion at at least a part of one end portion. The overall compressive strength of one end of the tube may be higher than the compressive strength of the intermediate portion from the viewpoint of easily suppressing deformation of the end. The compressive strength of one end of the tube may be higher than the overall compressive strength of the portion between the one end and the other end from the viewpoint of easily suppressing the deformation of the end.

In the first embodiment, the intermediate portion may be at least a part between one end portion and the other end portion. The middle portion may be the central portion of the tube in the axial direction (longitudinal direction) of the tube.

In the first embodiment, the compressive strength of the other end of the tube is preferably higher than the compressive strength of the intermediate portion. In this case, deformation of the other end is suppressed when lead powder, core metal, etc. are supplied from the other end, and the other end is suppressed by the stress applied by the sealing member attached to the other end. (For example, when the sealing member has a base and a protrusion described later, the other end of the tube is deformed due to contact with the base, and the other end and the protrusion of the tube are deformed. By suppressing the deformation of the other end portion due to the contact with the tube, the breakage of the tube can be further suppressed. The compressive strength of the other end may be equal to or less than the compressive strength of one end, and may be equal to or higher than the compressive strength of one end. The tube preferably has a portion having a compression strength higher than the compression strength of the intermediate portion at least a part of the other end portion. The overall compressive strength of the other end of the tube may be higher than the compressive strength of the intermediate portion from the viewpoint of easily suppressing deformation of the end. The compressive strength of the other end of the tube may be higher than the total compressive strength of the portion between the one end and the other end from the viewpoint of easily suppressing the deformation of the end.

The active material holding member according to the second embodiment is an active material holding member including a tube for holding the active material, and has a compressive strength of 3 N / mm ² or more at one end of the tube. In such an active material holding member, since the compressive strength of one end of the tube is high, deformation of the one end of the tube when supplying lead powder, core metal, etc. from the one end is suppressed. , The one end of the tube is deformed by the stress applied by the sealing member attached to the one end (for example, when the sealing member has a base and a protrusion described later, one end and the base of the tube Deformation of the one end due to contact with the tube and deformation of the one end due to contact between one end of the tube and the protrusion) are suppressed. As a result, it is possible to prevent the tube from being damaged, and it is possible to obtain excellent electrical characteristics (for example, discharge characteristics).

In the second embodiment, the tube ^{may have a portion having a compression strength of 3 N / mm 2} or more at at least a part of one end. The overall compressive strength of one end of the tube may be ^{3 N / mm 2 or more from the viewpoint of easily suppressing deformation of the end.} Compressive strength of the end portion of the tube, from the viewpoint of easily suppressing the deformation of the end portion, preferably 3.25N / mm ² or more, more preferably 3.3 N / mm ² or more, 3.4 N / mm ² or more further preferably, particularly preferably 3.5 N / mm ² or more, very preferably 3.75N / mm ² or more, 4N / mm ² or more is very preferred, more preferably more is 4.25N / mm ² or more, 4.5 N / mm ² or more, and particularly preferably from 4.75N / mm ² or more, 5N / mm ² or more is very preferred, highly preferred 5.25N / mm ² or more, and still more preferably, 5.3 N / mm ² or more .. Compressive strength of the end portion of the tube, 10 N / mm ² or less, 9N / mm ² or less, 8N / mm ² or less, 7N / mm ² or less, 6N / mm ² or less, 5.5 N / mm ² or less, 5.3 N / mm ² or less, 5N / mm ² or less, 4N / mm ² or less, 3.7 N / mm ² or less, 3.5 N / mm ² or less, 3.4 N / mm ² or less, or, 3.2 N / mm ² or less May be. From these viewpoints, the compressive strength of one end of the tube may be ^{3 to 10 N / mm 2.}

In the second embodiment, the compressive strength of the other end of the tube ^{is preferably 3 N / mm 2} or more. In this case, deformation of the other end is suppressed when lead powder, core metal, etc. are supplied from the other end, and the other end is suppressed by the stress applied by the sealing member attached to the other end. (For example, when the sealing member has a base and a protrusion described later, the other end of the tube is deformed due to contact with the base, and the other end and the protrusion of the tube are deformed. By suppressing the deformation of the other end portion due to the contact with the tube, the breakage of the tube can be further suppressed.

In the second embodiment, the tube ^{preferably has a portion having a compression strength of 3 N / mm 2} or more at least a part of the other end portion. The overall compressive strength of the other end of the tube may be ^{3 N / mm 2 or more from the viewpoint of easily suppressing deformation of the end.} Compressive strength of the other end portion of the tube, from the viewpoint of easily suppressing the deformation of the end portion, preferably 3.25N / mm ² or more, more preferably 3.3 N / mm ² or more, 3.4 N / mm ² or more More preferably, 3.5N / mm ² or more is particularly preferable, 3.75N / mm ² or more is extremely preferable, 4N / mm ² or more is very preferable, 4.25N / mm ² or more is even more preferable, and 4.5N. / mm ² or more, and particularly preferably from 4.75N / mm ² or more, 5N / mm ² or more is very preferred, 5.25N / mm ² or more is very preferred, 5.3 N / mm ² or more preferable. Compressive strength of the other end portion of the tube, 10 N / mm ² or less, 9N / mm ² or less, 8N / mm ² or less, 7N / mm ² or less, 6N / mm ² or less, 5.5 N / mm ² or less, 5. 3N / mm ² or less, 5N / mm ² or less, 4N / mm ² or less, 3.7N / mm ² or less, 3.5N / mm ² or less, 3.4N / mm ² or less, or 3.2N / mm ² It may be: From these viewpoints, the compressive strength of the other end of the tube may be ^{3 to 10 N / mm 2.}

In the second embodiment, the tube may have the structure of the tube of the first embodiment described above. For example, the compressive strength of one end of the tube may be higher than the compressive strength of the intermediate portion and may be ^{3 N / mm 2 or more.} The same applies to other configurations such as the relationship between the compression strength of the other end portion and the intermediate portion.

The compressive strength of the intermediate portion ^{may be 2.0 N / mm 2} or more. The ratio of the compression strength of one end to the compression strength of the middle part (compression strength of one end / the compression strength of the middle part) and / or the ratio of the compression strength of the other end to the compression strength of the middle part (the compression strength of the other end) The compression strength / the compression strength of the intermediate portion) may be in the following range. The ratio may exceed 1.0 and may be 1.2 or higher, 1.4 or higher, 1.6 or higher, 1.8 or higher, or 2.0 or higher. The ratios are 8.0 or less, 7.5 or less, 7.0 or less, 6.5 or less, 6.0 or less, 5.5 or less, 5.0 or less, 4.5 or less, 4.0 or less, 3. It may be 5 or less, 3.0 or less, or 2.5 or less. From these viewpoints, the ratio may be more than 1.0 and 8.0 or less.

In the first embodiment and the second embodiment, the compressive strength of the end portion and the intermediate portion of the tube can be measured using, for example, an autograph (EZ-FX, manufactured by Shimadzu Corporation). As one end and the other end, for example, a region having a length of 5 mm from each end can be used. The cross-sectional area of the tube at one end and the other end can be obtained by subtracting the area based on the inner diameter from the area based on the outer diameter when the cross section of the tube is a perfect circle. The compressive strength of the end portion and the intermediate portion of the tube can be adjusted by applying the resin material, the type and amount of the resin material, the thickness of the tube (for example, the number of times the base material constituting the tube is wound) and the like.

The compressive strength of the tube in the lead-acid battery after chemical conversion can be measured by, for example, the following procedure. First, the lead-acid battery after chemical conversion is disassembled, and the electrode having the tube is washed with running water for 12 hours. The electrodes are then dried in air at 45 ° C. for 72 hours. Subsequently, the tube is taken out from the electrode (for example, the boundary position between the upper punishment and the tube and the boundary position between the lower punishment and the tube are cut and the tube is taken out). Then, after removing the core metal and the active material from the inside of the tube, the compressive strength of the tube is measured.

The cross section of the tube perpendicular to the axial direction of the tube may be a perfect circle, an ellipse, or the like. The tube may be formed of a base material formed into a tubular shape.

In the first aspect, the tube may be formed by winding the base material, and is formed by spirally winding the base material from one end to the other end of the tube. It may be formed by spirally winding the base material. The substrate may be spirally or spirally wound counterclockwise or clockwise. The base material may be wound at least once, may be wound more than one round, and may be wound a plurality of times. "Spiral" means traveling in the extending direction of the central axis while orbiting around the central axis extending in a predetermined direction. "Swirl" means to orbit in the same plane. For example, in the case of a spiral shape, the tube expands as the base material is wound, whereas in the spiral shape, the tube becomes thicker as the base material is wound, but the tube does not expand. The winding direction (counterclockwise or clockwise) in the spiral case means the direction of rotation of the base material with respect to the central axis. The winding direction (counterclockwise or clockwise) in the case of a spiral means the winding direction when the base material is wound from the inner layer to the outer layer of the tube.

As a second aspect, the tube may be formed by joining (for example, suturing) resin sheets facing each other. In the second aspect, the active material holding member may include a plurality of tubes, and the base material forming one tube and the base material forming the other tube may be continuous. In this case, one tube and the other tube have a series of base materials (a series of continuous base materials), and the base material straddles one tube and another tube.

The active material holding member may be provided with a plurality of tubes, and may be a group of active material holding tubes having a plurality of tubes adjacent to each other. A structure in which a plurality of tubes are juxtaposed with each other may be obtained by juxtaposing tubes that are separate bodies from each other, or may be obtained by forming a plurality of through holes between substrates facing each other. .. A connecting portion such as a seam (sewn portion) may be arranged between adjacent tubes.

The tube may include a non-woven fabric, a woven fabric, etc., and includes, for example, a non-woven fabric. The tube can contain a resin material as a constituent material of the base material constituting the tube. The base material may include fibers (for example, fibers of a resin material). Examples of the resin material include polyester (for example, polyalkylene terephthalate such as polyethylene terephthalate), polyolefin (polyethylene, polypropylene, etc.), polystyrene, polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, polycarbonate and the like. The tube can contain, for example, polyester and can include a non-woven fabric containing polyester.

The content of the resin material in the base material may be 90% by mass or more, 95% by mass or more, 98% by mass or more, or 99% by mass or more based on the total amount of the base material. The base material may be substantially made of a resin material (the content of the resin material in the base material is substantially 100% by mass based on the total amount of the base material). The content of polyester in the base material may exceed 50% by mass, based on the total amount of the base material or the total amount of the resin material constituting the base material, and may exceed 60% by mass, 70% by mass or more, and 80% by mass. As mentioned above, it may be 90% by mass or more, 95% by mass or more, 98% by mass or more, or 99% by mass or more. The base material may be substantially made of polyester (the content of polyester in the base material is substantially 100% by mass based on the total amount of the base material). The resin material constituting the base material is substantially made of polyester (the content of polyester in the resin material constituting the base material is substantially 100% by mass based on the total amount of the resin material). You may. The tube does not have to contain polyolefin. The content of polyolefin in the base material is less than 50% by mass, 40% by mass or less, 30% by mass or less, 20% by mass or less, 10 based on the total amount of the base material or the total amount of the resin material constituting the base material. It may be mass% or less, 5 mass% or less, or 1 mass% or less.

If the tube contains fibers, the fibers may be oriented. For example, the non-woven fabric may have an MD direction (mechanical direction) in manufacturing the non-woven fabric and a CD direction (width direction) orthogonal to the MD direction. Since the fibers are easily oriented in the MD direction, the MD direction tends to have higher mechanical strength than the CD direction. Therefore, a resin sheet having high mechanical strength in the CD direction is a sheet having high mechanical strength even in a direction in which the mechanical strength is relatively low (CD direction). When the tube contains a non-woven fabric, it is easy to suppress the influence of mechanical strength due to the fiber orientation, so that the leakage of the active material is easily suppressed. Therefore, in at least one tube of the active material holding member, with respect to the axial direction of the tube. It is preferable that the MD direction and the CD direction of the non-woven fabric are inclined. The inclination angle in the MD direction or the CD direction with respect to the axial direction of the tube is preferably in the following range from the viewpoint that the influence of the mechanical strength due to the fiber orientation is easily suppressed and the leakage of the active material is easily suppressed. The inclination angle is preferably more than 0 °, more preferably 10 ° or more, further preferably 20 ° or more, particularly preferably 30 ° or more, extremely preferably 40 ° or more, and very preferably 43 ° or more. The inclination angle is preferably less than 90 °, more preferably 80 ° or less, further preferably 70 ° or less, particularly preferably 60 ° or less, extremely preferably 50 ° or less, and very preferably 47 ° or less. From these viewpoints, the inclination angle is preferably more than 0 ° and less than 90 °, more preferably 10 to 80 °, still more preferably 43 to 47 °. When the inclination angle is 45 °, it is presumed that the influence of mechanical strength due to fiber orientation is most easily suppressed.

At least one selected from the group consisting of one end and the other end of the tube can contain a resin material different from the above-mentioned resin material as a constituent material of the base material, and can be used as a constituent material of the base material. As a resin material different from the above-mentioned resin material, at least one selected from the group consisting of styrene resin, acrylic resin, and epoxy resin can be contained. In these cases, it is easy to increase the compressive strength of the end portion, so that it is easy to suppress the deformation of the end portion. In addition, it is easy to prevent the fibers constituting the base material from fraying and the edges of the base material from peeling off. Styrene resin is a resin having a structural unit derived from styrene. Examples of the styrene resin include polystyrene (styrene polymer) and ABS resin. At least one selected from the group consisting of one end and the other end of the tube may contain a monomer such as a styrene monomer. At least one selected from the group consisting of one end and the other end of the tube contains a resin material different from the above-mentioned resin material as a constituent material of the base material, so that the resin material not contained in the middle part of the tube is contained. May contain. The intermediate portion of the tube does not have to contain a resin material different from the above-mentioned resin material as a constituent material of the base material.

The tube may be a porous body having pores. The tube preferably includes a portion having an average pore diameter in the following range. The average pore diameter of the tube is preferably 60 μm or less, more preferably 50 μm or less, further preferably 45 μm or less, and particularly preferably 40 μm or less, from the viewpoint of easily suppressing the outflow of the electrode material. The average pore diameter of the tube is preferably more than 2 μm, more preferably 5 μm or more, further preferably 10 μm or more, particularly preferably 20 μm or more, extremely preferably 30 μm or more, and 35 μm or more from the viewpoint of easily reducing electrical resistance. Very preferred. From these viewpoints, the average pore diameter of the tube is preferably more than 2 μm and 60 μm or less. The average pore diameter can be measured with a pore distribution measuring device (for example, AUTO PORE IV 9520 manufactured by Shimadzu Corporation).

The tube may be provided with a portion having a thickness in the following range (thickness. Thickness of the wall portion constituting the tube. The same shall apply hereinafter). The thickness of the tube may be 0.05 mm or more, 0.1 mm or more, or 0.2 mm or more. The thickness of the tube may be 1 mm or less, 0.8 mm or less, 0.6 mm or less, or 0.4 mm or less. From these viewpoints, the thickness of the tube may be 0.05 to 1 mm. At least one selected from the group consisting of one end and the other end of the tube is preferably thicker than the middle portion from the viewpoint of easily suppressing deformation of the end portion. That is, one end of the tube may be thicker than the middle part, and the other end of the tube may be thicker than the middle part.

The length of at least one tube in the active material holding member may be in the following range. The length of the tube may be 50 mm or more, 100 mm or more, 120 mm or more, 160 mm or more, or 200 mm or more. The length of the tube may be 800 mm or less, 750 mm or less, 700 mm or less, 650 mm or less, 600 mm or less, or 580 mm or less. From these points of view, the length of the tube may be 50-800 mm.

In at least one tube in the active material holding member or at least a part of the tubes in the active material holding member, the holes in the range of 0.006 to 0.1 μm measured by the mercury intrusion method are the total pore amounts. It may be less than 10% by volume.

In at least one tube in the active material holding member or at least a part of the tubes in the active material holding member, the total pores of the pores having a pore diameter of 10 μm or more with respect to the total pore volume B of the pores having a pore diameter of less than 10 μm. The ratio A / B of the volume A may exceed 1.40. The total pore volume can be measured with a pore distribution meter (for example, trade name: AUTO PORE IV 9520 manufactured by Shimadzu Corporation). The ratio A / B can be adjusted according to the type or amount of the constituent material of the base material, the type or amount of the resin material used different from the resin material as the constituent material of the base material, and the like.

The active material holding member according to the present embodiment may include a sealing member that seals one end of the tube. The active material holding member according to the present embodiment may include a sealing member that seals the other end of the tube. The sealing member may have a protrusion extending in the axial direction of the tube in the internal space of the tube and in contact with the inner wall of the tube, and at least one selected from the group consisting of one end and the other end of the tube is a protrusion. May include a contact portion between the and the inner wall. In the active material holding member according to the present embodiment, even when the protrusion and the inner wall come into contact with each other, the end of the tube is affected by the stress applied by the protrusion due to the high compressive strength of the end of the tube. Deformation is likely to be suppressed. At least one selected from the group consisting of one end and the other end of the tube may include the entire contact portion between the protrusion and the inner wall. The protrusion may be a fitting portion that fits into at least one selected from the group consisting of one end and the other end of the tube. The sealing member may have a base located outside the tube and connected to a protrusion. The base may be in contact with the end of the tube and may not be in contact with the end of the tube. In the active material holding member according to the present embodiment, even when the base portion comes into contact with the end portion of the tube, it is easy to prevent the end portion of the tube from being deformed by the stress applied by the base portion.

The active material holding member and electrode according to the present embodiment are preferably used in a liquid lead-acid battery (active material holding member and electrode for a liquid lead-acid battery), and the lead storage battery according to the present embodiment is a liquid lead-acid battery. It is preferably a storage battery. Generally, in a liquid-type lead-acid battery, the entire electrode tends to be immersed in the electrolytic solution, and the amount of the electrolytic solution tends to be larger than that of a control valve type lead-acid battery or the like. In this case, since the discharge capacity is not easily regulated by the amount of the electrolytic solution, the discharge capacity tends to be increased. However, in a liquid lead-acid battery, the stratification of the electrolytic solution increases the concentration of sulfuric acid in the region below the electrode, and the base material below the tube in the electrode tends to deteriorate. Further, in a liquid lead-acid battery, as the deterioration over time (including deterioration due to the charge / discharge cycle) progresses, the active material (for example, the positive electrode active material) becomes muddy, and the active material easily leaks out. Become. If the tube is broken in these cases, the active material will leak significantly. On the other hand, in the active material holding member according to the present embodiment, since the tube can be suppressed from being damaged, the advantages of the liquid lead-acid battery can be utilized while suppressing the leakage of the active material.

An example of the lead storage battery according to the present embodiment will be described with reference to FIGS. 1 and 2. 1 and 2 are schematic cross-sectional views showing an example of a lead storage battery. In FIG. 1, positive electrodes and negative electrodes are alternately arranged via separators from the front side to the back side of the drawing. FIG. 1 (b) is an enlarged view showing a region P of FIG. 1 (a). In FIG. 1A, the details inside the tubes and the details of the portions where the tubes are adjacent to each other are omitted. The lead-acid batteries shown in FIGS. 1 and 2 are provided with an electric tank extending in the vertical direction, and FIG. 2 shows a positive electrode when the lead-acid battery is viewed from above in the vertical direction (above in the height direction of the electric tank). , The laminated structure of the negative electrode and the separator is shown.

The lead-acid battery 100 shown in FIGS. 1 and 2 is connected to an electrode group 110, an electric tank 120 accommodating the electrode group 110, connecting

members

130a and 130b connected to the electrode group 110, and connecting

members

130a and 130b. The

electrode columns

140a and 140b are provided, a liquid port plug 150 for closing the liquid injection port of the electric tank 120, and a support member 160 connected to the electric tank 120.

The electrode group 110 includes a plurality of positive electrodes 10, a plurality of negative electrodes 20, and a plurality of separators 30. The positive electrode 10 and the negative electrode 20 are alternately arranged via the separator 30. Silica particles do not have to be arranged between the positive electrode 10 and the negative electrode 20. The space around the positive electrode 10 between the separators 30 is filled with the electrolytic solution 40. The electrolytic solution 40 may contain sulfuric acid. The electrolytic solution 40 may contain aluminum ions, sodium ions and the like. The electrolytic solution 40 does not have to contain silica particles.

The positive electrode 10 is, for example, a plate-shaped electrode (positive electrode plate), and includes an active material holding member 50, a core metal (current collector) 60, a positive electrode material 70 containing an active material, and an ear portion 80. are doing. The active material holding member 50 has a plurality of tubes 52 for holding the active material, a lower joint (sealing member) 54, and an upper joint 56.

The tube 52 is formed of a tubular portion capable of accommodating the positive electrode material 70. The tube 52 extends in the height direction (vertical direction) of the electric tank 120. The tube 52 has one end 52a (lower end in the drawing), the other end 52b (upper end in the drawing), and an intermediate portion 52c between the one end 52a and the other end 52b. Have. The compressive strength of the one end 52a and the other end 52b may be higher than the compression strength of the intermediate 52c, and may be ^{3 N / mm 2 or more.}

The lower punishment 54 seals one end 52a of the tube 52, and the upper punishment 56 seals the other end 52b of the tube 52. The lower joint 54 and the upper joint 56 are in contact with the tube 52 and the core metal 60 and the positive electrode material 70 arranged in the tube 52. The lower joint 54 is connected to a base 54a extending in a direction orthogonal to the axial direction of the tube 52 (longitudinal direction, for example, the height direction of the battery case 120), and is connected to the base 54a and fitted to one end 52a of the tube 52. It has a plurality of fitting portions (projections) 54b. The fitting portion 54b is formed with a recess into which the end portion of the core metal 60 is inserted. The fitting portion 54b and the inner wall 52d of the tube 52 are in contact with each other at the contact portion 90. One end portion 52a of the tube 52 includes a contact portion 90 in which the fitting portion 54b and the inner wall 52d come into contact with each other. The upper punishment 56 may have the same configuration as the lower punishment 54, and may have a plurality of fitting portions (projections) to be fitted to the other end 52b of the tube 52.

The core metal 60 extends in the axial direction of the tube 52 at the center of the tube 52. The constituent material of the core metal 60 may be any conductive material, and examples thereof include lead alloys such as lead-calcium-tin alloys and lead-antimony-arsenic alloys. The cross-sectional shape perpendicular to the axial direction (longitudinal direction) of the core metal 60 may be circular, elliptical, or the like. The length of the core metal 60 is, for example, 160 to 650 mm. The diameter of the core metal 60 is, for example, 2.0 to 4.0 mm.

The positive electrode material 70 is filled between the tube 52 and the core metal 60. The positive electrode material 70 contains a positive electrode active material after chemical conversion. The chemicalized positive electrode material can be obtained, for example, by chemicalizing an unchemicald positive electrode material containing a raw material for the positive electrode active material. Examples of the raw material for the positive electrode active material include lead powder and lead tan. Examples of the positive electrode active material in the positive electrode material after chemical conversion include lead dioxide and the like. The positive electrode material 70 can further contain an additive if necessary. Examples of the additive for the positive electrode material 70 include short reinforcing fibers. Examples of the reinforcing short fibers include acrylic fibers, polyethylene fibers, polypropylene fibers, polyethylene terephthalate fibers (PET fibers) and the like.

One end of the selvage 80 (lower end in the figure) is connected to the upper collective punishment 56, and the other end of the selvage 80 (upper end in the figure) is connected to the connecting member 130a. The core metal 60 housed in the tube 52 is electrically connected to the pole pillar 140a via the upper connecting seat 56, the selvage portion 80, and the connecting member 130a.

The support member 160 has a plurality of protrusions 160a extending in the axial direction of the tube 52, and the lower joint 54 is fixed in contact with the plurality of protrusions 160a. That is, the support member 160 supports the portion of the lower joint 54 on the bottom surface side of the electric tank 120 by the protrusions 160a.

The negative electrode 20 is, for example, a plate-shaped negative electrode plate, for example, a paste type negative electrode plate. The negative electrode 20 has a negative electrode current collector and a negative electrode material held by the negative electrode current collector. As the negative electrode current collector, a plate-shaped current collector can be used. The composition of the negative electrode current collector and the core metal 60 of the positive electrode 10 may be the same or different from each other. The negative electrode 20 is electrically connected to the pole pillar 140b via the connecting member 130b.

The negative electrode material contains the negative electrode active material after chemical conversion. The chemical negative electrode material can be obtained, for example, by chemicalizing an unchemicald negative electrode material containing a raw material for the negative electrode active material. Examples of the raw material for the negative electrode active material include lead powder and the like. Examples of the negative electrode active material in the negative electrode material after chemical conversion include porous spongy lead and the like. The negative electrode material can further contain an additive if necessary. Examples of the additive for the negative electrode material include barium sulfate, reinforcing short fibers, a carbon material (carbon conductive material), a surfactant (lignin sulfonate, etc.) and the like. As the reinforcing short fiber, the same reinforcing short fiber as the positive electrode material can be used. Examples of the carbon material include carbon black and graphite. Examples of carbon black include furnace black (Ketjen black (registered trademark), etc.), channel black, acetylene black, thermal black, and the like.

The material of the separator 30 is not particularly limited as long as it is a material that blocks the electrical connection between the positive electrode 10 and the negative electrode 20 and allows the electrolytic solution to permeate. Examples of the material of the separator 30 include microporous polyethylene; a mixture of glass fiber and synthetic resin.

The method for manufacturing a lead-acid battery according to the present embodiment includes an assembly step of assembling a component including an electrode having an active material holding member to obtain a lead-acid battery. In the assembling step, for example, a non-chemical positive electrode and a non-chemical negative electrode are laminated, and the current collecting portions of electrodes having the same polarity are welded with a strap to obtain an electrode group. This group of electrodes is arranged in the battery case to produce an unchemical battery. The unchemical positive electrode and the unchemical negative electrode may be laminated via a separator.

The lead-acid battery manufacturing method according to the present embodiment may include an active material holding member manufacturing step for manufacturing an active material holding member before the assembling step. The active material holding member manufacturing step may include a tube manufacturing step of molding a base material to obtain a tube. In the tube manufacturing step in the first aspect of the active material holding member manufacturing step, the tube may be formed by winding the base material, for example, the tube may be formed by winding the base material in a spiral or spiral shape. .. The first aspect of the active material holding member manufacturing step may include a step of arranging a plurality of tubes in a direction orthogonal to the axial direction of the tubes after the tube manufacturing step. In the tube manufacturing step in the second aspect of the active material holding member manufacturing step, the tube may be formed by joining the base materials facing each other.

The active material holding member manufacturing step may include a sealing step of sealing one end of the tube with a sealing member after the tube manufacturing step. In the active material holding member manufacturing step, after the tube manufacturing step, a resin that imparts a resin material different from the resin material as the constituent material of the base material to at least one selected from the group consisting of one end and the other end of the tube. It may be provided with a granting process. In the resin applying step, at least one selected from the group consisting of one end and the other end of the tube may be given at least one selected from the group consisting of styrene resin, acrylic resin, and epoxy resin. In the resin applying step, a monomer (styrene monomer or the like) may be added to at least one selected from the group consisting of one end and the other end of the tube, and at least one selected from the group consisting of one end and the other end of the tube. A resin material (for example, styrene resin) and a monomer (for example, styrene monomer) different from the resin material as the constituent material of the base material may be added to the material.

When a resin material (for example, styrene resin) and a monomer (for example, styrene monomer) different from the resin material as the constituent material of the base material are applied to at least one selected from the group consisting of one end and the other end of the tube. The content ratio of the resin material based on the total amount of the resin material and the monomer may be in the following range. The content ratio of the resin material is 1% by mass or more, 3% by mass or more, 5% by mass or more, 8% by mass or more, 10% by mass or more, 12% by mass or more, 15% by mass or more, 20% by mass or more, 25% by mass. As mentioned above, it may be 30% by mass or more, or 35% by mass or more. The content ratio of the resin material may be 50% by mass or less, less than 50% by mass, 45% by mass or less, 40% by mass or less, or 35% by mass or less. From these viewpoints, the content ratio of the resin material may be 1 to 50% by mass. The higher the content ratio of the resin material, the higher the compressive strength at the end of the tube can be easily obtained.

The lead-acid battery manufacturing method according to the present embodiment may include an electrode manufacturing step of manufacturing an electrode having an active material holding member. The electrode manufacturing step includes a positive electrode manufacturing step and a negative electrode manufacturing step. Hereinafter, a case where the positive electrode has an active material holding member will be described.

In the positive electrode manufacturing step, a positive electrode having a core metal inserted in a tube of an active material holding member and a positive electrode material (undigenized positive electrode material) filled between the tube and the core metal is obtained. The positive electrode manufacturing step includes, for example, a filling step of arranging a core metal in a tube and then filling a raw material (for example, lead powder) of an active material between the core metal and the tube. The positive electrode manufacturing step may include a step of sealing the other end of the tube with a sealing member after the filling step.

In the negative electrode manufacturing step, for example, a negative electrode material paste containing a raw material for a negative electrode active material is filled in a negative electrode current collector (for example, a current collector lattice (cast lattice body, expanded lattice body, etc.)), and then aged and dried. Therefore, a negative electrode having a non-chemical negative electrode material can be obtained.

The lead-acid battery manufacturing method according to the present embodiment may include a chemical conversion treatment step of performing a chemical conversion treatment of a positive electrode and a negative electrode. The chemical conversion treatment step may be carried out after the assembling step, or may be carried out in the electrode manufacturing step before the assembling step (tank chemical conversion). In the chemical conversion treatment step, for example, the chemical conversion treatment is performed by energizing a direct current while the positive electrode and the negative electrode are in contact with the electrolytic solution. A lead storage battery can be obtained by adjusting the specific gravity of the electrolytic solution after chemical conversion to an appropriate specific gravity.

The electric vehicle (for example, an electric vehicle) or the power supply device according to the present embodiment includes the lead storage battery according to the present embodiment. The method for manufacturing an electric vehicle or a power supply device according to the present embodiment includes a step of obtaining a lead-acid battery by the method for manufacturing a lead-acid battery according to the present embodiment. The method for manufacturing an electric vehicle or a power supply device according to the present embodiment is, for example, a step of obtaining a lead-acid battery by the method for manufacturing a lead-acid battery according to the present embodiment and an electric vehicle or a power supply device by assembling a component including the lead-acid battery. It has a process to obtain. Examples of the electric vehicle include a forklift and a golf cart. Examples of the power supply device include UPS, disaster prevention (emergency) wireless power supply, telephone power supply, and the like. According to the present embodiment, a lead-acid battery for an electric vehicle (for example, a lead-acid battery for an electric vehicle) is provided, and for example, a lead-acid battery for a forklift is provided. According to this embodiment, a lead storage battery for a power supply device is provided.

In lead-acid batteries for electric vehicles, it is easy to design a large electrode height in the battery height direction. Therefore, since sulfuric acid in the electrolytic solution tends to settle downward, maintenance for preventing stratification is important. Therefore, there is a case where the electrolytic solution is agitated by gassing by overcharging at the end of charging. In this case, if the tube is broken and the active material leaks out, the active material is likely to fly up due to this gassing and deposit on the electrode (for example, the negative electrode), resulting in a short circuit. On the other hand, the lead-acid battery according to the present embodiment can suppress breakage of the tube and thus can suppress a short circuit caused by gassing, so that it can be suitably used in an electric vehicle.

Hereinafter, the content of the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

<Making a tube>
(Example 1)
A polyester non-woven fabric sheet (average pore diameter: 40 μm, basis weight: 100 g / m ² ) was impregnated with an acrylic resin emulsion for 1 minute. Then, it was dried in a constant temperature bath at 100 ° C. for 1 hour to obtain a non-woven fabric in which an acrylic resin was held on a polyester base material. A tube (cross-sectional shape: circular, inner diameter: 9 mm, thickness: 0.4 mm, length: 294 mm) was prepared by winding this non-woven fabric around a mandrel having a diameter of 9 mm and welding the ends of the non-woven fabric to each other by heat welding. Subsequently, a solution consisting of 35% by mass of the styrene polymer and 65% by mass of the styrene monomer was attached to both ends of the tube so that the resin processing length was 10 mm, and then the styrene monomer was dried until it was dried to perform resin processing. Was given.

(Example 2)
A tube was obtained in the same manner as in Example 1 except that the solution applied to both ends of the tube consisted of 15% by mass of styrene polymer and 85% by mass of styrene monomer.

(Example 3)
A tube was obtained in the same manner as in Example 1 except that the solution applied to both ends of the tube consisted of 10% by mass of styrene polymer and 90% by mass of styrene monomer.

(Example 4)
A tube was obtained in the same manner as in Example 1 except that the solution applied to both ends of the tube consisted of 5% by mass of styrene polymer and 95% by mass of styrene monomer.

(Comparative Example 1)
A tube was obtained in the same manner as in Example 1 except that no solution was applied to both ends (both ends) of the tube.

<Measurement of compression strength>
Two test pieces were obtained by cutting both ends of the tube 5 mm so as not to lose their shape. With the cut part of the test piece arranged downward in the vertical direction, the cut part (cross section) of the test piece is compressed at a compression speed of 5 mm / min using an autograph (EZ-FX, manufactured by Shimadzu Corporation). The compression strength was measured by the above. Compressive strength of the distal portion are both 5.3 N / mm ² in Example 1, are both 3.7 N / mm ² in Example 2, are both 3.4 N / mm ² in Example 3, performed are both 3N / mm ² in example 4, were both at 2.5 N / mm ² Comparative example 1.

The middle portion of the tubes of Examples 1 to 4 was cut by 5 mm so as not to lose its shape, and a test piece was obtained in which the central portion of the tube was located on one of the cut portions (cross sections). The compression strength was measured by the same method as above. The compressive strength of the intermediate portion was ^{2.5 N / mm 2.}

<Measurement of thickness>
A test piece was obtained by cutting both the end portion and the intermediate portion of the tubes of Examples 1 to 4 in the same manner as in the measurement of the compressive strength. The thickness (thickness) of the tube at the end and the middle was measured with a caliper. It was confirmed that the thickness of both ends was thicker than that of the middle part.

<Evaluation of pores>
In the tubes of Examples 1 to 4, the pores in the range of 0.006 to 0.1 μm measured by the mercury intrusion method were less than 10% by volume of the total pore amount.
In the tubes of Examples 1 to 4, the ratio A / B of the total pore volume A of the pores having a pore diameter of 10 μm or more to the total pore volume B of the pores having a pore diameter of less than 10 μm exceeded 1.40. .. The pore volume ratio of the tube was calculated based on the pore distribution. The pore distribution of the tube was measured using a pore distribution meter (manufactured by Shimadzu Corporation, trade name: AUTO PORE IV 9520). For the pore volume ratio of the tube, the volume of each pore obtained from the measurement result of the pore distribution is defined as "total pore volume of pores having a pore diameter of 10 μm or more" and "total fineness of pores having a pore diameter of less than 10 μm". It was separated into "pore volume" and calculated based on "total pore volume of pores having a pore diameter of 10 μm or more" / "total pore volume of pores having a pore diameter of less than 10 μm".

<Preparation of electrodes>
After arranging the 15 tubes, the punishment was attached to one end of the tubes. Then, a lead-antimony (4.0% by mass) -arsenic (0.2% by mass) -tin (0.015% by mass) alloy core metal (diameter 2.7 mmφ x length 299 mm columnar) is formed. An electrode plate having 15 tubes was obtained by inserting the lead powder containing lead monoxide as a main component into the tube from the other end side of the tube and filling the tube with lead powder containing lead monoxide as a main component.

<Confirmation of tube damage>
The presence or absence of damage (deformation) was confirmed by visually checking the other end of the tube of the electrode plate described above. No damage was confirmed in Examples 1 to 4. In Comparative Example 1, damage was confirmed. By suppressing the breakage of the tube, the leakage of the active material can be suppressed, and the life reduction due to the short circuit due to the dropout of the active material can be suppressed.

10 ... positive electrode, 20 ... negative electrode, 30 ... separator, 50 ... active material holding member, 52 ... tube, 52a ... one end, 52b ... other end, 52c ... intermediate part, 52d ... inner wall, 54 ... lower joint (sealing) Member), 54b ... Fitting portion (protrusion portion), 90 ... Contact portion, 100 ... Lead storage battery.

Claims

An active material holding member having a tube for holding the active material.
The tube has one end, the other end, and an intermediate portion between the one end and the other end.
An active material holding member having a compression strength at one end higher than the compression strength at the intermediate portion.
The active material holding member according to claim 1, wherein the compressive strength of the other end of the tube is higher than the compressive strength of the intermediate portion.
The active material holding member according to claim 1 or 2, wherein the one end portion of the tube is thicker than the intermediate portion.
An active material holding member having a tube for holding the active material.
An active material holding member having a compressive strength of 3 N / mm 2 or more at one end of the tube.
The active material holding member according to claim 4, wherein the compressive strength of the other end of the tube is 3 N / mm 2 or more.
A sealing member for sealing the one end of the tube is further provided.
The sealing member has a protrusion extending in the axial direction of the tube and in contact with the inner wall of the tube.
The active material holding member according to any one of claims 1 to 5, wherein the one end portion includes a contact portion between the protrusion portion and the inner wall.
The active material holding member according to any one of claims 1 to 6, wherein the average pore diameter of the tube exceeds 2 μm.
The active material holding member according to any one of claims 1 to 7, wherein the tube is formed by spirally winding a base material from one end to the other end.
With multiple tubes
The active material holding member according to any one of claims 1 to 7, wherein the base material forming one of the tubes and the other base material forming the tube are continuous.
The active material holding member according to any one of claims 1 to 9, wherein one end thereof contains at least one selected from the group consisting of styrene resin, acrylic resin, and epoxy resin.
An electrode having the active material holding member according to any one of claims 1 to 10 and the active material held in the tube of the active material holding member.
Equipped with positive and negative electrodes
The lead-acid battery, wherein at least one selected from the group consisting of the positive electrode and the negative electrode is the electrode according to claim 11.
The lead-acid battery according to claim 12, further comprising a separator arranged between the positive electrode and the negative electrode.
An electric vehicle comprising the lead-acid battery according to claim 12 or 13.