WO2019097575A1

WO2019097575A1 - Lead storage battery

Info

Publication number: WO2019097575A1
Application number: PCT/JP2017/040943
Authority: WO
Inventors: 真輔小林
Original assignee: 日立化成株式会社
Priority date: 2017-11-14
Filing date: 2017-11-14
Publication date: 2019-05-23
Also published as: JPWO2019097575A1; JP7093788B2; JP2022120197A

Abstract

A lead storage battery according to one embodiment of the present invention is provided with: a battery case, which has a cell chamber and an open top; an electrode group and an electrolytic solution, which are stored in the cell chamber; and a lid that closes the opening. The electrode group has a plurality of negative electrodes and a plurality of positive electrodes, and the negative electrodes are connected to each other by means of a strap formed of an alloy containing Pb and Sn.

Description

Lead storage battery

The present invention relates to a lead storage battery.

In recent years, various measures for improving fuel consumption have been considered for preventing air pollution or global warming in automobiles. For example, an idling stop system car (hereinafter, also referred to as "ISS car") that reduces the operating time of the engine, and a micro control vehicle such as a power generation control car that reduces the power generation of the alternator by the power of the engine. Hybrid vehicles are being considered.

In ISS cars and micro hybrid cars, high current charging of lead acid batteries is repeated by regenerative charging etc., though for a short time. When the large current charging is repeated, electrolysis of water in the electrolyte is likely to occur, and accordingly, oxygen gas and hydrogen gas may be generated, and the pressure in the lead storage battery may be increased. On the other hand, in order to release the pressure, the lid of the lead storage battery may be provided with an exhaust plug. In this case, since the mist of the electrolytic solution is also discharged to the outside of the battery through the exhaust plug, the amount of the electrolytic solution is reduced, and it is necessary to perform maintenance by replenishing the reduced amount of the electrolytic solution. However, since it is desirable that lead-acid batteries be maintenance-free, it is required to suppress the decrease (liquid reduction) of the electrolyte.

As a means for suppressing liquid reduction, for example, as disclosed in Patent Document 1, an exhaust chamber is provided inside a lid of a lead storage battery, and generated electrolytic solution mist is retained in the exhaust chamber to be liquefied and liquefied. It is known to reflux the electrolyte into the cell.

JP 2005-166318 A

However, the means as disclosed in Patent Document 1 can not necessarily suppress the liquid reduction sufficiently. Then, an object of this invention is to provide the lead storage battery excellent in the point of liquid reduction suppression.

The present invention includes, in one aspect, a battery case having a cell chamber and having an open upper surface, an electrode group and an electrolytic solution accommodated in the cell chamber, and a lid for closing the opening; It is a lead storage battery which has several negative electrodes and several positive electrodes, and several negative electrodes are connected by the strap formed of the alloy containing Pb and Sn.

The lid includes a first lid, a second lid provided on the first lid, and an exhaust chamber formed between the first lid and the second lid. The bottom wall of the first lid separating the exhaust chamber and the cell chamber may be provided with a reflux hole for refluxing the electrolyte into the cell chamber.

The negative electrode may contain a resin having a structural unit derived from a phenolic compound. The structural unit may contain a structural unit derived from a bisphenol-based compound. The structural unit may include structural units derived from lignin.

The negative electrode may contain a carbon material. The carbon material may contain carbon black.

ADVANTAGE OF THE INVENTION According to this invention, the lead acid battery excellent in the point of liquid reduction suppression can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view which shows the whole structure of the lead acid battery which concerns on one Embodiment. It is a perspective view which shows the battery case of the lead storage battery shown in FIG. It is a top view of the 1st lid part of the lead storage battery shown in FIG. It is a bottom view of the 2nd cover part of the lead storage battery shown in FIG. FIG. 5 is a cross-sectional view taken along the line VV of FIG. 3; It is a perspective view of the electrode plate group of the lead storage battery shown in FIG.

Hereinafter, embodiments of the present invention will be described in detail.

FIG. 1 is a perspective view showing an entire configuration of a lead storage battery of an embodiment. As shown in FIG. 1, in one embodiment, the lead storage battery 1 is a liquid lead storage battery including a battery case 2 whose upper surface is open and a lid 3 for closing the opening of the battery case 2.

FIG. 2 is a perspective view showing the battery case 2 of the lead storage battery 1 shown in FIG. As shown in FIG. 2, the battery case 2 is, for example, a hollow rectangular parallelepiped. The bottom of the battery case 2 has a rectangular shape, and the substantially entire upper surface of the battery case 2 is open. The battery case 2 is formed of, for example, polypropylene. In the present specification, the direction along the long side and the direction along the short side of the bottom surface of the battery case 2 are respectively taken as the longitudinal direction and the short direction of the battery case 2.

The inside of the battery case 2 is divided into six sections by, for example, five partitions 21 provided substantially in parallel with the short side direction of the battery case 2. Thus, first to sixth cell chambers 22a to 22f (hereinafter collectively referred to as "cell chamber 22") are formed inside the battery case 2 along the longitudinal direction of the battery case 2. It is done. An electrode group (electrode plate group, details will be described later) is accommodated in each of the cell chambers 22.

Each electrode group is also called a single cell, and its electromotive force is 2 V, for example. For example, since a lead storage battery for an automobile is driven by boosting or stepping down a DC voltage 12 V, six electrode groups accommodated in each of six cell chambers 22 are connected in series, and 2 V × 6 It has an electromotive force of 12 V. The number of cell chambers 22 is not limited to six. It is suitably selected according to the use of the lead storage battery 1.

As shown in FIG. 2, the side walls of the partition 21 (surfaces substantially parallel to the short direction of the battery case 2) and the inner surfaces of the pair of side walls 23 substantially parallel to the partition 21 of the battery case 2 A plurality of ribs (rib portions) 24 extending in the height direction of 2 (the direction perpendicular to the opening surface) may be provided. That is, both side surfaces of the partition wall 21 and the inner surface of the side wall 23 may have the flat portion 25 and a plurality of ribs 24 protruding from the flat portion 25 and extending in the height direction of the battery case 2. The rib 24 has a function of appropriately pressing (compressing) the electrode group inserted in the cell chamber 22 in the stacking direction of the electrodes.

As shown in FIG. 1, the lid 3 has a double lid structure including a first lid 4 and a second lid 5, and the first lid 4 and the second lid 5 A plurality of exhaust chambers D1 to D6 are formed between them. That is, the lid 3 has a first lid 4, a second lid 5, and an exhaust chamber formed between the first lid 4 and the second lid 5. The lid 3 has a substantially rectangular shape in a plan view, and in each direction along the four sides of the rectangle, one end and the other end of the lid 3 in the longitudinal direction are one end and the other end of the battery case 2 in the longitudinal direction. They are provided on the battery case 2 in a state in which one end and the other end in the short direction of the lid 3 are respectively matched with one end and the other end in the short direction of the battery case 2. The lid 3 (the first lid 4 and the second lid 5) is made of, for example, polypropylene.

In the lid 3, a hollow protrusion 6 protruding upward from the upper surface of the first lid 4 is formed in a region of the upper surface of the first lid 4 where the second lid 5 is not provided. ing. An indicator mounting hole 7 is formed in a part of the protrusion 6. The indicator mounting hole 7 is used to mount an indicator (not shown) that indicates the liquid level of the electrolyte in the battery case. In the present embodiment, the indicator attachment hole 7 is provided above one of the cell chambers provided in the battery case 2, and the indicator for displaying the liquid level of the electrolytic solution in the cell chamber is used. It can be attached to the indicator attachment hole 7. In the present embodiment, the liquid level level of the electrolytic solution in another cell chamber is estimated by displaying the liquid level level of the electrolytic solution in one cell chamber on the indicator.

In the lid 3, the negative electrode terminal 8 and the positive electrode terminal 9 are formed in a region of the upper surface of the first lid 4 where the second lid 5 is not provided. The negative electrode terminal 8 and the positive electrode terminal 9 are connected to the electrode plate group accommodated in the battery case 2 via the negative electrode column and the positive electrode column.

Hereinafter, the details of the lid 3 will be described with reference to FIGS. 3 to 5. FIG. 3 is a plan view of the first lid, and FIG. 4 is a bottom view of the second lid. FIG. 5 is a cross-sectional view taken along the line VV of FIG. 3, and is a cross-sectional view of the lid 3 in a state in which the first lid 4 and the second lid 5 are welded.

As shown in FIG. 3, the first lid 4 has a substantially rectangular shape in plan view, and the second lid 5 is disposed on a part of the first lid 4. An exhaust chamber configuration 400 is formed. The exhaust chamber configuration 400 places the one end 400 a and the other end 400 b in the longitudinal direction near the one end 4 a and the other end 4 b in the longitudinal direction of the first lid 4, and the one end 400 c in the lateral direction as the first. Positioned near the center of the lid 4 in the width direction, and the other end 400 d in the width direction is positioned near the other end 4 d in the width direction (width direction of the battery case) of the first lid 4 It is formed in the A peripheral wall portion 40 extending along the outer peripheral edge is formed on the upper surface of the exhaust chamber configuration portion 400, and a first lid side concave portion is formed inside the peripheral wall portion 40. In the example shown in FIG. 3, in order to expand the width dimension (the length in the short direction) of the portion near the one end 4 a in the longitudinal direction and the portion near the other end 4 b of the exhaust chamber configuration 400, the exhaust chamber configuration 400 The protrusion parts 401 and 402 which protruded in the one end side of the transversal direction rather than the part of the center of the longitudinal direction are formed.

As shown in FIG. 4, the second lid 5 has the same contour as the exhaust chamber configuration 400, and the exhaust chamber configuration is provided on one end 5a side and the other end 5b side in the longitudinal direction. Similar to the protrusions 401 and 402 at both ends of the portion 400,

protrusions

501 and 502 protruding in the short direction are formed. Further, as shown in FIG. 4, a peripheral wall 50 extending along the outer peripheral edge is also formed on the lower surface of the second cover 5, and a second cover side recess is formed inside the peripheral wall 50. ing. In the example shown in FIG. 4, an outer wall 51 surrounding the outer side of the peripheral wall 50 is formed on the lower surface of the second lid 5.

The second lid 5 is provided on the exhaust chamber configuration 400, and the first lid 4 and the second lid 5 are joined by thermal welding. Specifically, the second lid 5 aligns one end 5a and the other end 5b in the longitudinal direction of the second lid 5 with the one end 4a and the other end 4b in the longitudinal direction of the first lid 4 respectively. The exhaust chamber with the one end 5c and the other end 5d of the second cover 5 in the short direction aligned with the one end 400c and the other end 400d of the exhaust chamber configuration of the first cover 4 respectively. It is disposed on component 400. Further, the exhaust chamber configuration 400 and the second lid 5 are joined together in a state where the peripheral wall 40 and the peripheral wall 50 are combined, and the first lid side concave portion and the second lid side A space for forming an exhaust chamber is formed between the exhaust chamber configuration 400 of the first cover 4 and the second cover 5 by the recess.

In the space between the exhaust chamber configuration 400 of the first cover 4 and the second cover 5, the first to sixth cell chambers 22a to 22f are positioned above the first to sixth cell chambers 22a to 22f, respectively. Six exhaust chambers D1 to D6 are formed (see FIGS. 3 and 4). These exhaust chambers are formed of the exhaust chamber forming portion 400 of the first cover 4 and the peripheral wall 50 of the second cover 5 with a predetermined thickness, and a first partition of a predetermined pattern. 42 and 52 are formed by being mutually joined. The exhaust chambers D1 to D6 have a function of keeping the mist of the electrolytic solution generated from each cell chamber 22 in the battery case 2 inside, and refluxing the liquefied electrolytic solution in the exhaust chamber into the respective cell chambers 22. .

In the present embodiment, a part of the first exhaust chamber D1 and the sixth exhaust chamber D6 disposed at both ends is provided to the first lid 4 and the second lid 5 as a first partition wall. By dividing by the

second partitions

42a and 52a formed in parts of 42 and 52, one end 400a side and the other end 400b side of the exhaust chamber configuration 400 of the first cover 4 in the longitudinal direction, and Centralized exhaust chambers E1 and E2 are formed on one end 5a side and the other end 5b side in the longitudinal direction of the second lid 5, respectively.

Each exhaust chamber has a pair of opposed longitudinal inner side surfaces Sa and Sb facing in the longitudinal direction of the first lid 4 and a pair facing the opposite direction in the lateral direction of the first lid 4 And four corner portions C1 to C4 are formed in each exhaust chamber. In the present specification, for convenience of explanation, of the four inner side surfaces Sa to Sd of the exhaust chambers, the inner side surfaces Sa and Sb opposed to the longitudinal direction of the first lid 4 are referred to as the longitudinal inner side surfaces. The inner side surfaces Sc and Sd opposed to the short side direction of the first cover 4 are referred to as the short side inner side surface.

In the three exhaust chambers D1 to D3 disposed near one longitudinal end 4a of the first cover 4, the first cover 4 of the pair of longitudinal inner side surfaces of the first cover 4 is provided. The longitudinal inner surface located on the one end 4a side in the longitudinal direction is one longitudinal inner surface Sa, and the longitudinal inner surface located on the other end 4b side of the first lid 4 in the longitudinal direction is the other longitudinal direction It is referred to as the inner side Sb. Further, in the other three exhaust chambers D4 to D6 arranged closer to the other end 4b in the longitudinal direction of the first lid 4, the length of the first lid 4 among the pair of longitudinal inner side surfaces The longitudinal inner surface located on the other end 4b side of the direction is one longitudinal inner surface Sa, and the longitudinal inner surface located on the longitudinal end 4a of the first cover 4 is the other longitudinal inner surface It is referred to as Sb.

The exhaust chambers D1 to D6 are formed in a substantially square shape in plan view, but the first exhaust chamber D1 and the sixth exhaust chamber D6 disposed at both ends in the longitudinal direction of the first lid 4 are respectively formed By forming the centralized exhaust chambers E1 and E2 in a part of the first, the one longitudinal inner side surface Sa has a deformed shape.

As described above, the exhaust chambers D1 to D6 and the central exhaust chambers E1 and E2 are formed between the exhaust chamber forming portion 400 of the first cover 4 and the second cover 5, and further, As described later, various fluid passages for connecting the exhaust chambers D1 to D6 to the central exhaust chambers E1 and E2 are formed. These fluid passages are constituted by the

first partition portions

42 and 52 provided in the first lid 4 and the second lid 5 and joined to each other, but in the following description, mainly the first The configuration of the fluid passage provided between the first cover 4 and the second cover 5 will be described with reference to FIG. 3 showing the cover 4 of FIG. The patterns of the walls provided on the first lid and the second lid to form the exhaust chamber, the fluid passage and the like are in mirror image to each other.

As shown in FIG. 3, a first longitudinal fluid passage L1 and a second longitudinal fluid passage L2 are provided between the exhaust chamber configuration 400 of the first lid 4 and the second lid 5. A first short direction fluid passage W1a and a second short direction fluid passage W1b are formed.

The first longitudinal fluid passage L1 is located on the other end 400d side in the width direction of the exhaust chamber configuration 400, and the outer side of the exhaust chamber D1 to D6 (between the exhaust chamber D1 to D6 and the peripheral wall portion 40) It is provided to extend linearly along the longitudinal direction of the component 400. The width dimension (length in the lateral direction) of the first longitudinal fluid passage L1 at positions corresponding to the protrusions 401 and 402 of the exhaust chamber configuration 400 on one end side and the other end side in the longitudinal direction, respectively. Enlarged enlarged portions L11 and L12 are formed. The ends of the enlarged portions L11 and L12 of the first longitudinal fluid passages L1 are flow paths 43 formed between the first exhaust chamber D1 and the sixth exhaust chamber D6 and the peripheral wall portion 40, and Through 44, the central exhaust chambers E1 and E2 are connected.

The second longitudinal fluid passage L2 linearly extends outside the exhaust chambers D1 to D6 (between the exhaust chambers D1 to D6 and the peripheral wall portion 40) on one end 400c side of the exhaust chamber configuration 400 in the short direction. It is provided to extend. The first short direction fluid passage W1a and the second short direction fluid passage W1b are respectively disposed between the second and third exhaust chambers D2 and D3 and the fourth and fifth exhaust chambers D4 and D5 which are adjacent to each other. Between the first and second longitudinal fluid passages L1 and L2, the first longitudinal fluid passage L1 and the second longitudinal fluid passage L2 are connected.

The second longitudinal fluid passage L2 is partitioned into a first portion L2a and a second portion L2b by a partition wall 45 provided at the central portion in the longitudinal direction of the exhaust chamber configuration 400. The first longitudinal fluid passage L1 passes through the first transverse fluid passage W1a and the second transverse fluid passage W1b to form a first portion L2a and a second portion of the second longitudinal fluid passage L2. Each is connected to L2b.

As shown in FIG. 3, electrolyte injection is carried out in the exhaust chambers D1 to D6 through the bottom walls of the exhaust chambers that separate the exhaust chambers from the corresponding cell chambers 22a to 22f. A reflux hole h having a size also serving as the hole is provided. The reflux hole h is formed between the longitudinal inner surface Sa of one of the exhaust chambers and the lateral surface Sc of one of the exhaust chambers located on the second longitudinal fluid passage L2 side. It is located in the vicinity of the corner portion C1 of 1, and only one is provided in each exhaust chamber. The exhaust chambers D1 to D6 are connected to the first to sixth cell chambers 22a to 22f through the reflux holes h provided in the respective bottom walls.

In each of the exhaust chambers of the first cover 4 and the second cover 5, fluid

passage forming walls

46 and 56 extending along the other longitudinal inner side surface Sb of each exhaust chamber are provided. A third short direction fluid passage W2 extending in the short direction of the exhaust chamber configuration 400 is formed between the fluid

passage forming walls

46 and 56 and the longitudinal inner side surface Sb. One end of the third short direction fluid passage W2 opens to the fourth corner C4 at the diagonal position of the first corner C1 and the other end opens into the second longitudinal fluid passage L2 doing.

In each exhaust chamber of the first cover 4 and the second cover 5, a wall for forming a fluid passage in the vicinity of the opening at one end of the third short direction fluid passage W2 (near the fourth corner C4)

First barrier portions

47, 57 integrated with the

portions

46, 56 are provided. The

first barrier portions

47, 57 project from the fluid

passage forming walls

46, 56 toward one longitudinal inner side Sa of each exhaust chamber, and terminate at a position before the one longitudinal inner side Sa. doing. The

first barrier portions

47 and 57 are provided integrally with the first lid 4 and the second lid 5. An electrolyte solution accommodation space A is formed between the

first barrier portions

47 and 57 and one short side inner side surface Sc. The end positions of the tips of the

first barrier portions

47 and 57 are set so as to position at least a part of the reflux hole h in the electrolyte solution accommodation space A.

In each exhaust chamber of the first cover 4 and the second cover 5, one longitudinal facing surface Sc of each exhaust chamber is located closer to the

first barrier portions

47 and 57 than the return hole h. A

second barrier portion

48, 58 is provided to extend from the electrolyte containing space A to the fluid

passage forming wall

46, 56 side. The

barriers

48 and 58 are provided integrally with the first lid 4 and the second lid 5. The

second barrier portions

48, 58 are inclined to the second corner portion C2 side formed between the other longitudinal inner side surface Sb of each exhaust chamber and one shorter side inner side surface Sc. It is provided. The tips of the

second barrier portions

48 and 58 are terminated at positions before the fluid

passage forming walls

46 and 56.

In each exhaust chamber of the first cover 4 and the second cover 5, the second barrier 48 is provided along the short direction of the exhaust chamber from the position just before the tip of the

first barriers

47 and 57. , 58, and further provided with first projecting

wall portions

47a, 57a which end at positions before the

second barrier portions

48, 58. In each exhaust chamber, a position in front of the tip of the

second barrier portion

48, 58 is projected to one short side inner side surface Sc side of each exhaust chamber, and a short side of one short side inner side surface Sc The second projecting

wall portions

48a and 58a terminated at the end are further provided. The first projecting

wall portions

47 a and 57 a and the second projecting

wall portions

48 a and 58 a are provided integrally with the first lid 4 and the second lid 5.

In the first lid 4, the upper surface of the bottom wall of each exhaust chamber is gradually lowered toward the reflux hole h from the vicinity of the opening at one end of the third short direction fluid passage W 2 Is inclined. The bottom surface of the first longitudinal fluid passage L1 is gradually lowered toward the portion where the first and second transverse fluid passages W1a and W1b and the first longitudinal fluid passage L1 meet. It is inclined to go. The bottoms of the first and second short direction fluid passages W1a and W1b are inclined so that they gradually decrease from the first longitudinal fluid passage L1 side toward the second longitudinal fluid passage L2 side. It is attached. The bottom surface of the second longitudinal fluid passage L2 is inclined so as to be gradually lowered toward the opening of the other end of the third transverse fluid passage W2 provided in each exhaust chamber. There is. In FIG. 3, the inclination of each part described above is indicated by an arrow. Each arrow indicates that the front end side is lower than the rear end side. With such a configuration, the mist of the electrolyte solution discharged into the exhaust chambers from the reflux holes h in the exhaust chambers is the

first barrier portions

47 and 57, the

second barrier portions

48 and 58, and the first projecting wall. After contacting and liquefying the 47a, 57a and the second projecting

wall

48a, 58a, it is possible to return to the reflux hole h of each exhaust chamber along the bottom surface of each exhaust chamber.

As shown in FIG. 4, at one end and the other end of the second lid 5 in the longitudinal direction, an exhaust port 65 for opening the centralized exhaust chambers E1 and E2 to the outside is formed. An explosion-proof filter 66 is accommodated in the central exhaust chambers E1 and E2. Exhaust gas that has flowed into the concentrated exhaust chambers through the first longitudinal fluid passage L1 is discharged to the outside through the explosion-proof filter 66 and the exhaust port 65.

A liquid injection port 60 is formed in the second lid 5. The injection port 60 is provided at a position aligned with the reflux hole h in each exhaust chamber. At the inner periphery of the injection port 60, a screw for attaching a stopper is formed.

As shown in FIG. 5, the lid 3 is provided with a welded portion 405 and a positioning rib 406. The welding portion 405 is welded to the upper end of the partition dividing the cell chamber by the battery case when the lid 3 is attached to the battery case 2 and forms a wall portion separating the cell chamber together with the battery case side partition wall Do. Further, the positioning rib 406 engages with the side surface of the upper end of the partition between the cell chambers on the side of the battery case when the welded portion 405 is welded to the upper end of the partition between the cell chambers of the battery case 2 It is a positioning rib which positions 405 with respect to the partition by the side of a battery case.

In the above embodiment, the liquid injection hole is provided in the second lid 5, but the liquid injection hole is not provided in the second lid 5, and after injecting the electrolytic solution, the first cover 4 is formed. And the second lid 5 may be welded.

In the above embodiment, of the pair of transverse direction inner side surfaces Sc and Sd of each exhaust chamber, Sc is one transverse side inner side surface, and Sd is the other transverse direction inner side surface. These may be respectively one short side inner side and the other short side inner side. Similarly, Sb may be one longitudinal inner side, and Sa may be the other longitudinal inner side.

In the above-mentioned embodiment, although the reflux hole h is comprised by the aggregate | assembly of several holes, the reflux hole h may be comprised by a single hole. The reflux hole h can also be made to have a function as a vent, by making the reflux hole h larger or increasing the number of the holes constituting the reflux hole h.

In the above-mentioned embodiment, although the 1st

projection wall parts

47a and 57a and the 2nd

projection wall parts

48a and 58a were provided, the 1st

projection wall parts

47a and 57a and the 2nd projection The

walls

48a and 58a may not be provided.

Then, the electrode group accommodated in each of the cell chamber 22 is demonstrated. FIG. 6 is a perspective view showing an electrode group. As shown in FIG. 6, the electrode group 10 includes a plate-like negative electrode (negative electrode plate) 11, a plate-like positive electrode (positive electrode plate) 12, and a separator 13 disposed between the negative electrode 11 and the positive electrode 12. Is equipped. The negative electrode 11 includes a negative electrode current collector (negative electrode grid body) 14 and a negative electrode active material 15 held by the negative electrode current collector 14. The positive electrode 12 includes a positive electrode current collector (positive electrode grid body) 16 and a positive electrode active material 17 held by the positive electrode current collector 16. In the present specification, the negative electrode after formation with the negative electrode collector removed is defined as “negative electrode active material”, and the positive electrode after formation with the positive electrode collector removed is defined as “positive electrode active material”. .

The electrode group 10 has a structure in which a plurality of negative electrodes 11 and positive electrodes 12 are alternately stacked in a direction substantially parallel to the opening surface of the battery case 2 via the separators 13. That is, the electrode group 10 is accommodated in each of the cell chambers 22 such that the main surfaces of the negative electrode 11 and the positive electrode 12 extend in the direction perpendicular to the opening surface of the battery case 2.

In the electrode group 10, the ear portions 11a of the respective negative electrode current collectors 14 of the plurality of negative electrodes 11 are connected (for example, collective welding) by straps (negative electrode side straps) 18. Similarly, the ear portions 12 a of the positive electrode current collectors 16 of the plurality of positive electrodes 12 are connected (for example, collective welding) by straps (positive electrode side straps) 19. The negative electrode side strap 18 and the positive electrode side strap 19 are connected to the negative electrode terminal 8 and the positive electrode terminal 9 via the negative electrode column and the positive electrode column, respectively.

The separator 13 is formed in, for example, a bag shape, and accommodates the negative electrode 11. The separator 13 is made of, for example, polyethylene (PE), polypropylene (PP) or the like. The separator 13 may be obtained by adhering inorganic particles such as SiO ₂ and Al ₂ O ₃ to a woven fabric, a non-woven fabric, a porous film or the like formed of these materials.

The negative electrode current collector 14 and the positive electrode current collector 16 are each formed of a lead alloy. The lead alloy may be an alloy containing, in addition to Pb, Sn, Ca, Sb, Se, Ag, Bi, etc. Specifically, for example, an alloy containing Pb, Sn and Ca (Pb-Sn -Ca-based alloy).

The negative electrode active material 15 contains at least Pb (single substance) as a Pb component, and may further contain a Pb component other than Pb (for example, PbSO ₄ ) and an additive, if necessary. The negative electrode active material 15 preferably contains porous sponge lead as a Pb component.

The content of the Pb component may be 90% by mass or more or 95% by mass or more, and may be 99% by mass or less or 98% by mass or less based on the total mass of the negative electrode active material.

The negative electrode active material 15 preferably further includes, as an additive, a resin having a structural unit derived from a phenolic compound (hereinafter, also referred to as “phenolic resin”) from the viewpoint of further suppressing liquid reduction. That is, preferably, the negative electrode 11 further includes, in the negative electrode active material 15, a resin having a structural unit derived from a phenolic compound. The phenolic resin preferably further comprises a sulfonic acid group (sulfo group) or a sulfonic acid group. In this case, the sulfonic acid group or the sulfonate group may be contained in the structural unit derived from the phenolic compound, and may be contained in a structural unit other than the structural unit derived from the phenolic compound Good.

The content of the phenolic resin may be 0.01 mass% or more, 0.05 mass% or more, or 0.1 mass% or more, 2 mass% or less, 1 mass based on the total mass of the negative electrode active material. % Or less or 0.5 mass% or less.

The structural unit derived from the phenolic compound preferably includes a structural unit derived from a bisphenol compound from the viewpoint of being able to particularly suppress liquid reduction, and from the viewpoint of achieving both suppression of liquid reduction and excellent DCA performance, Preferably, it comprises structural units derived from lignin. That is, the phenol resin is a bisphenol resin (also referred to as a "bisphenol resin" hereinafter) containing a sulfonic acid group or a sulfonate group from the viewpoint of suppressing liquid reduction particularly, and the DCA suppresses the liquid reduction and is excellent From the viewpoint of compatibility with the performance, lignin sulfonic acid or a salt thereof (hereinafter also referred to as “lignin sulfonic acid (salt)”) is preferable.

The bisphenol resin has a structural unit derived from a bisphenol compound as a structural unit derived from a phenol compound. The bisphenol resin is, for example, a compound having (a) a bisphenol compound (hereinafter also referred to as “component (a)”) and (b) a sulfonic acid group (sulfo group) (hereinafter also referred to as “component (b)”) In the reactions of and, it can be obtained by replacing the hydrogen atom of the sulfonic acid group with, for example, a metal atom, if necessary. In the reaction of the component (a) and the component (b), at least one selected from the group consisting of (c) formaldehyde and a formaldehyde derivative (hereinafter also referred to as "component (c)") may be further reacted.

As the component (a), for example, 2,2-bis (4-hydroxyphenyl) propane (hereinafter also referred to as “bisphenol A”), bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ) Ethane, 2,2-bis (4-hydroxyphenyl) hexafluoropropane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, 2,2-bis (4-hydroxyphenyl) butane, bis ( 4-hydroxyphenyl) diphenylmethane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, and bis (4-hydroxyphenyl) Sulfone (hereinafter also referred to as "bisphenol S") can be mentioned. The component (a) can be used alone or in combination of two or more. The component (a) is preferably bisphenol A from the viewpoint of further excellent charge acceptance, and preferably bisphenol S from the viewpoint of further excellent discharge characteristics.

As the component (a), it is preferable to use bisphenol A and bisphenol S in combination, from the viewpoint of improving charge acceptance, discharge characteristics and cycle characteristics in a well-balanced manner. In this case, the content of bisphenol A in the reaction for obtaining a bisphenol resin is preferably based on the total amount of bisphenol A and bisphenol S from the viewpoint of improving charge acceptance, discharge characteristics and cycle characteristics in a well-balanced manner. It is 70 mol% or more, more preferably 75 mol% or more, and still more preferably 80 mol% or more. The content of bisphenol A is preferably 99 mol% or less, more preferably 98 mol% or less based on the total amount of bisphenol A and bisphenol S from the viewpoint of improving charge acceptance, discharge characteristics and cycle characteristics in a well-balanced manner. More preferably, it is 97 mol% or less.

The component (b) may be a compound having an amino group and a sulfonic acid group. Examples of the compound having an amino group and a sulfonic acid group include 4-aminobenzenesulfonic acid (also called sulfanilic acid), aminoethylsulfonic acid (also called taurine), and 5-amino-1-naphthalenesulfonic acid (also called laurent acid) Can be mentioned.

The component (b) can be used alone or in combination of two or more. The component (b) is preferably 4-aminobenzenesulfonic acid from the viewpoint of further improving charge acceptance.

The content of the component (b) in the reaction for obtaining a bisphenol resin is preferably 0.5 mol or more, more preferably 0. 1 mol, per 1 mol of the component (a), from the viewpoint of further improving the discharge characteristics. It is at least 6 mol, more preferably at least 0.7 mol, particularly preferably at least 0.8 mol. The content of the component (b) is preferably 2.0 mol or less, more preferably 1.5 mol or less, and further preferably 1 mol or less with respect to 1 mol of the component (a) from the viewpoint of facilitating further improvement of the discharge characteristics and cycle characteristics. It is preferably at most 1.3 mol, particularly preferably at most 1.0 mol.

As formaldehyde which is the component (c), formaldehyde in formalin (for example, an aqueous solution of 37% by mass of formaldehyde) may be used. Examples of formaldehyde derivatives include paraformaldehyde, hexamethylenetetramine and trioxane. The component (c) can be used alone or in combination of two or more. As the component (c), formaldehyde and a formaldehyde derivative may be used in combination.

The component (c) is preferably a formaldehyde derivative, more preferably paraformaldehyde, from the viewpoint of easily obtaining excellent cycle characteristics. Paraformaldehyde has, for example, a structure represented by the following formula (1).
HO (CH ₂ O) _{n 1} H (1)
In the formula (1), n1 represents an integer of 2 to 100.

From the viewpoint of improving the reactivity of the component (b), the compounding amount of the component (c) in the reaction for obtaining a bisphenol resin is preferably 2 mol or more, relative to 1 mol of the component (a), from the viewpoint of improving the reactivity of the component (b) More preferably, it is 2.2 mol or more, still more preferably 2.4 mol or more. The compounding amount of the component (c) in terms of formaldehyde is obtained by the reaction of the components (a), (b) and (c) and from the viewpoint of easily reducing the structural unit having a benzoxazine ring, the component (a) The amount is preferably 3.5 mol or less, more preferably 3.2 mol or less, still more preferably 3 mol or less, particularly preferably less than 2.8 mol, and most preferably 2.5 mol or less, per 1 mol.

The bisphenol resin preferably has at least one of a structural unit represented by the following formula (I) and a structural unit represented by the following formula (II).

In formula (I), X ¹ represents a divalent group, Y ¹ represents a divalent aromatic hydrocarbon group, an aliphatic hydrocarbon group or an alicyclic hydrocarbon group, and R ¹¹ , R ¹² and Each R ¹³ independently represents a metal atom or a hydrogen atom, n 11 represents an integer of 1 to 300, and n 12 represents an integer of 1 to 3. The hydrogen atom directly bonded to the carbon atom constituting the benzene ring may be substituted by an alkyl group of 1 to 5 carbon atoms.

In formula (II), X ² represents a divalent group, and Y ² represents a divalent aromatic hydrocarbon group, an aliphatic hydrocarbon group or an alicyclic hydrocarbon group, and R ²¹ , R ²² and Each R ²³ independently represents a metal atom or a hydrogen atom, n 21 represents an integer of 1 to 300, and n 22 represents an integer of 1 to 3. The hydrogen atom directly bonded to the carbon atom constituting the benzene ring may be substituted by an alkyl group of 1 to 5 carbon atoms.

The ratio of the structural unit represented by the formula (I) and the structural unit represented by the formula (II) is not particularly limited, and may vary depending on synthesis conditions and the like. As a bisphenol resin, you may use resin which has only any one of the structural unit represented by Formula (I), and the structural unit represented by Formula (II).

As X ¹ and X ² , an alkylidene group (eg, methylidene group, ethylidene group, isopropylidene group and sec-butylidene group), a cycloalkylidene group (eg, cyclohexylidene group), a phenyl alkylidene group (eg, diphenylmethylidene group and phenyl) Organic groups such as ethylidene group); sulfonyl group etc. may be mentioned. As X ¹ and X ² , an isopropylidene group (—C (CH ₃ ) ₂ —) is preferable from the viewpoint of further excellent charge acceptance, and a sulfonyl group (—SO ₂ —) is preferred from the viewpoint of further excellent discharge characteristics. preferable. X ¹ and X ² may be substituted by a halogen atom such as a fluorine atom. When X ¹ or X ² is a cycloalkylidene group, the hydrocarbon ring may be substituted by an alkyl group or the like.

Examples of the divalent aromatic hydrocarbon group represented by Y ¹ or Y ² include a phenylene group and a naphthylene group, and examples of the divalent aliphatic hydrocarbon group include an ethylene group and a trimethylene group, and a divalent alicyclic group. As a formula hydrocarbon group, a cyclohexylidene group is mentioned, for example. Y ¹ and Y ² are preferably a phenylene group or a naphthylene group from the viewpoint of further excellent charge acceptance. The divalent aromatic hydrocarbon group, aliphatic hydrocarbon group or alicyclic hydrocarbon group represented by Y ¹ and Y ² may be substituted by a halogen atom such as a fluorine atom.

The metal atom represented by R ¹¹ , R ¹² , R ¹³ , R ²¹ , R ²² or R ²³ is, for example, a sodium atom, a potassium atom, a magnesium atom or a calcium atom.

The bisphenol resin may have, for example, structural units represented by the following formulas (III) to (VI). The reason why the structural units represented by the formulas (III) to (VI) are formed is presumed to be the addition reaction of the formaldehyde component to the benzene ring of the component (a).

X ³ , X ⁴ , X ⁵ and X ⁶ have the same meaning as X ¹ and X ² respectively, and R ³¹ , R ³² , R ³³ , R ⁴¹ , R ⁴² , R ⁴³ , R ⁵¹ , R ⁵² , R ⁶¹ And R ⁶² each independently has the same meaning as R ²¹ , R ²² and R ²³ , n 31, n 41, n 51 and n 61 each independently has the same meaning as n 11 and n 21, and n 32 and n 42 each independently is n 12 And n22. The hydrogen atom directly bonded to the carbon atom constituting the benzene ring may be substituted by an alkyl group of 1 to 5 carbon atoms.

The weight average molecular weight of the bisphenol resin is preferably 20000 or more, more preferably 30000 or more, still more preferably 40000 or more, particularly preferably 50000 or more, from the viewpoint of further improving the cycle characteristics. The weight average molecular weight of the bisphenol resin is preferably 80,000 or less, more preferably 70,000 or less, still more preferably 60000 or less, from the viewpoint of further improving the cycle characteristics. From these viewpoints, the weight average molecular weight of the bisphenol resin is preferably 20,000 to 80,000, more preferably 30,000 to 70,000, still more preferably 40,000 to 60000, and particularly preferably 50,000 to 60000.

The weight average molecular weight of the bisphenol resin can be measured, for example, by gel permeation chromatography (hereinafter referred to as "GPC") under the following conditions.
(GPC conditions)
Device: High-performance liquid chromatograph LC-2200 Plus (manufactured by JASCO Corporation)
Pump: PU-2080
Differential Refractometer: RI-2031
Detector: UV-visible spectrophotometer UV-2075 (λ: 254 nm)
Column oven: CO-2065
Column: TSKgel SuperAW (4000), TSKgel SuperAW (3000), TSKgel SuperAW (2500) (manufactured by Tosoh Corporation)
Column temperature: 40 ° C
Eluent: methanol solution containing LiBr (10 mM) and triethylamine (200 mM) Flow rate: 0.6 mL / min Molecular weight standard sample: polyethylene glycol (molecular weight: 1.10 × 10 ⁶ , 5.80 × 10 ⁵ , 2.55 × 10 ⁵ , 1.46 × 10 ⁵ , 1.01 × 10 ⁵ , 4.49 × 10 ⁴ , 2.70 × 10 ⁴ , 2.10 × 10 ⁴ ; manufactured by Tosoh Corporation, diethylene glycol (molecular weight: 1 .06 × 10 ² ; manufactured by Kishida Chemical Co., Ltd., dibutylhydroxytoluene (molecular weight: 2.20 × 10 ² ; manufactured by Kishida Chemical Co., Ltd.)

The method for producing a bisphenol-based resin includes, for example, a resin-producing step of reacting a component (a), a component (b) and a component (c) to obtain a bisphenol-based resin. The bisphenol resin can be obtained, for example, by reacting component (a), component (b) and component (c) in a reaction solvent. The reaction solvent is preferably water (eg, ion exchanged water). In this step, an organic solvent, a catalyst, an additive, or the like may be used to promote the reaction.

In the resin production process, the compounding amount of the component (b) is 0.5 to 2.0 moles to 1 mole of the component (a) from the viewpoint of further improving the cycle characteristics, and the compounding of the component (c) An embodiment in which the amount is 2 to 3.5 mol in terms of formaldehyde relative to 1 mol of the component (a) is preferable, and the blending amount of the component (b) is 0.5 to 2.0 per 1 mol of the component (a) More preferable is an embodiment in which the amount of component (c) is 2 to 2.5 moles in terms of formaldehyde relative to 1 mole of component (a). The preferable blending amounts of the components (b) and (c) are the ranges described above for the blending amounts of the components (b) and (c).

The bisphenol resin is preferably obtained by reacting the components (a), (b) and (c) under basic conditions (alkaline conditions), from the viewpoint that a sufficient amount of bisphenol resin can be easily obtained. . A basic compound may be used to adjust to basic conditions. Examples of the basic compound include potassium hydroxide and potassium carbonate. The basic compounds can be used alone or in combination of two or more. The basic compound is preferably potassium hydroxide from the viewpoint of excellent reactivity.

When the reaction solution at the time of reaction is neutral (pH = 7), the reaction for producing a bisphenol resin may not progress easily, and when the reaction solution is acidic (pH <7), side reactions (eg, benzo In some cases, the reaction of producing a structural unit having an oxazine ring may proceed. Therefore, the pH of the reaction solution at the time of reaction is preferably alkaline (more than 7), and more preferably 7., from the viewpoint of easily suppressing the progress of the side reaction while advancing the formation reaction of the bisphenol resin. It is at least one, more preferably at least 7.2. The pH of the reaction solution is preferably 12 or less, more preferably 10 or less, and still more preferably 9 or less, from the viewpoint of suppressing the progress of hydrolysis of the group derived from the component (b) in the bisphenol resin. The pH of the reaction solution can be measured, for example, with a twin pH meter AS-212 manufactured by HORIBA, Ltd. The pH is defined as the pH at 25 ° C.

The content of the strongly basic compound is preferably 1.01 mol or more, more preferably 1.02 mol or more, and still more preferably 1 mol of the component (b) because it is easy to adjust to the pH as described above. Is 1.03 mol or more. From the same viewpoint, the compounding amount of the strongly basic compound is preferably 1.1 mol or less, more preferably 1.08 mol or less, still more preferably 1.07 mol or less, per 1 mol of component (b). is there. Examples of strongly basic compounds include potassium hydroxide and potassium carbonate.

In the synthesis reaction of the bisphenol resin, the (a) component, the (b) component and the (c) component may be reacted to obtain the bisphenol resin, for example, the (a) component, the (b) component and the (c) The components may be reacted simultaneously, or after the two components of the components (a), (b) and (c) are reacted, the remaining one component may be reacted.

The synthesis reaction of the bisphenol-based resin is preferably performed in two steps as follows. In the first step reaction, for example, after charging the component (b), the solvent (such as water) and the basic compound, stirring is performed, and the hydrogen atom of the sulfo group in the component (b) is substituted with a metal atom such as potassium To obtain a metal salt such as potassium salt of component (b). This makes it easy to suppress side reactions in the condensation reaction described later. The temperature of the reaction system is preferably 0 ° C. or more, more preferably 25 ° C. or more from the viewpoint of excellent solubility of the component (b) in a solvent (such as water). The temperature of the reaction system is preferably 80 ° C. or less, more preferably 70 ° C. or less, and still more preferably 65 ° C. or less from the viewpoint of easily suppressing side reactions. The reaction time is, for example, 30 minutes.

In the reaction of the second step, for example, the component (a) and the component (c) are added to the reaction product obtained in the first step to cause a condensation reaction to obtain a bisphenol resin. The temperature of the reaction system is preferably 75 ° C. or more, more preferably 85 ° C. or more, from the viewpoint of excellent reactivity of the components (a), (b) and (c) and from the viewpoint of reduction of side reaction products. C. or higher, more preferably 92.degree. C. or higher. The temperature of the reaction system is preferably 100 ° C. or less, more preferably 98 ° C. or less, still more preferably 96 ° C. or less, from the viewpoint of easily suppressing side reactions. The reaction time is, for example, 5 to 20 hours.

The content of the bisphenol-based resin may be 0.01% by mass or more, 0.05% by mass or more, or 0.1% by mass or more, 2% by mass or less, or 1% by mass, based on the total mass of the negative electrode active material. % Or less or 0.5 mass% or less.

Lignin sulfonic acid (salt) is lignin sulfonic acid or a salt thereof in which a part of lignin degradation product is sulfonated. Lignin sulfonic acid (salt) has a structural unit derived from lignin as a structural unit derived from a phenolic compound and also has a sulfonic acid group or a sulfonate group. The lignin sulfonic acid (salt) has, for example, a structure in which a sulfonic acid group or a sulfonate group is bonded to a carbon atom at the α position adjacent to a phenylene group. The salt of lignin sulfonic acid may be, for example, a sodium salt, a potassium salt, a magnesium salt or a calcium salt.

The lignin sulfonic acid (salt) is obtained, for example, by neutralizing the black liquor remaining after the wood chips are digested to take out the cellulose with sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide, etc. Can.

The weight average molecular weight of lignin sulfonic acid (salt) is preferably 3,000 or more, from the viewpoint of further suppressing the elution of lignin sulfonic acid (salt) from the electrode to the electrolytic solution in the lead storage battery and obtaining further excellent cycle characteristics. More preferably, it is 7,000 or more, more preferably 8,000 or more. The weight average molecular weight of lignin sulfonic acid (salt) is preferably 70000 or less, more preferably 50000 or less, still more preferably 40000 or less, particularly preferably 30000 or less, very preferably 20000, from the viewpoint of excellent dispersibility of the electrode active material. It is below. From these viewpoints, the weight average molecular weight of lignin sulfonic acid (salt) is preferably 3000 to 70000, more preferably 3000 to 50000, still more preferably 3000 to 40000, particularly preferably 7000 to 30000, and very preferably 8000 to 20000. It is. The weight average molecular weight of lignin sulfonic acid (salt) can be measured by the same method as the weight average molecular weight of bisphenol resin.

The content of lignin sulfonic acid (salt) may be 0.01% by mass or more, 0.05% by mass or more, or 0.1% by mass or more, and 2% by mass or less based on the total mass of the negative electrode active material It may be 1% by mass or less or 0.5% by mass or less.

The negative electrode active material 15 may further contain a carbon material as an additive. That is, the negative electrode 11 may further contain a carbon material in the negative electrode active material 15. The carbon material may contain, for example, carbon black, graphite or the like, and preferably contains carbon black from the viewpoint of being able to further suppress liquid reduction. Examples of carbon black include furnace black, channel black, acetylene black, thermal black and ketjen black.

The content of the carbon material may be 0.1% by mass or more, 0.5% by mass or more, 1.0% by mass or more, or 1.5% by mass or more, based on the total mass of the negative electrode active material, 3 .5 mass% or less, 3.0 mass% or less, 2.5 mass% or less, or 2.0 mass% or less.

The negative electrode active material 15 may further contain barium sulfate, reinforcing short fibers and the like as an additive. That is, the negative electrode 11 may further contain barium sulfate, reinforcing short fibers and the like in the negative electrode active material 15. Examples of reinforcing staple fibers include acrylic fibers, polyethylene fibers, polypropylene fibers, polyethylene terephthalate fibers and the like. The content of barium sulfate may be, for example, 0.5% by mass or more and 3.0% by mass or less based on the total mass of the negative electrode active material. The content of reinforcing short fibers may be, for example, 0.05% by mass or more and 0.3% by mass or less based on the total mass of the negative electrode active material.

The positive electrode active material 17 contains at least PbO ₂ as a Pb component, and may further contain a Pb component other than PbO ₂ (for example, PbSO ₄ ) and an additive, if necessary.

The content of the Pb component may be 90% by mass or more or 95% by mass or more, and may be 99% by mass or less or 98% by mass or less based on the total mass of the positive electrode active material.

Examples of the additive include carbon materials (excluding carbon fibers) and reinforcing staple fibers (acrylic fibers, polyethylene fibers, polypropylene fibers, polyethylene terephthalate fibers, etc.). Examples of the carbon material include carbon black and graphite. Examples of carbon black include furnace black, channel black, acetylene black, thermal black and ketjen black.

The negative electrode side strap 18 connecting the negative electrodes 11 to each other is formed of an alloy containing Pb and Sn (hereinafter referred to as “Pb—Sn-based alloy”) from the viewpoint of suppressing liquid reduction. The content of Pb is 85 mass% or more, 90 mass% or more, 92 mass% or more, 95 mass% or more, 98 mass% or more, or 99 mass% or more, based on the total mass of the Pb-Sn alloy. You may

The content of Sn is preferably 1% by mass or more, more preferably 2% by mass or more, based on the total mass of the Pb--Sn alloy from the viewpoint of improving the strength of the alloy and suppressing corrosion of the alloy. Preferably it is 5 mass% or more. The content of Sn is preferably 15% by mass or less, more preferably 10% by mass or less, still more preferably 8% by mass or less, based on the total mass of the Pb—Sn-based alloy, from the viewpoint of further suppressing liquid reduction. is there.

The Pb—Sn-based alloy may further contain other components such as As, Se, etc. in addition to Pb and Sn. The content (total amount) of the other components may be 0.1% by mass or more and 1% by mass or less based on the total mass of the Pb—Sn-based alloy.

Similarly to the negative electrode side strap 18, the positive electrode side strap 19 connecting the positive electrodes 12 may be formed of a Pb—Sn based alloy, or may be formed of a lead alloy other than the Pb—Sn based alloy. The positive side strap 19 is preferably made of the same alloy as the negative side strap 18.

The lead storage battery 1 described above is suitably used as a lead storage battery for an idling stop system car or for a micro hybrid car. That is, one embodiment of the present invention is an application of the above-described lead storage battery 1 to an idling stop system car or an application to a micro hybrid car.

The lead storage battery 1 described above is manufactured by, for example, a manufacturing method including an electrode manufacturing process for obtaining an electrode (a negative electrode and a positive electrode) and an assembly process for assembling a component including the electrode to obtain the lead storage battery 1.

In the electrode manufacturing process, for example, after holding the negative electrode active material paste on the negative electrode current collector 14, aging and drying are performed to obtain the unformed negative electrode 11, and the positive electrode current collector 16 holds the positive electrode active material paste. Then, the unformed positive electrode 12 is obtained by aging and drying under the conditions described above.

The negative electrode active material paste contains, for example, lead powder, an additive, a solvent (eg, water or an organic solvent) and sulfuric acid (eg, dilute sulfuric acid). The negative electrode active material paste is obtained, for example, by mixing lead powder and an additive to obtain a mixture, and then adding a solvent and sulfuric acid to the mixture and kneading.

The positive electrode active material paste contains, for example, lead powder, optionally added additives, a solvent (for example, water or an organic solvent) and sulfuric acid (for example, dilute sulfuric acid). The positive electrode active material paste may further contain red lead (Pb ₃ O ₄ ) from the viewpoint of shortening the formation time.

The lead powder is, for example, a lead powder manufactured by a ball mill type lead powder manufacturing machine or a Burton pot type lead powder manufacturing machine (in the ball mill type lead powder manufacturing machine, a mixture of a powder of main component PbO and scaly metallic lead Can be mentioned.

Aging may be performed for 15 to 60 hours in an atmosphere at a temperature of 35 to 85 ° C. and a humidity of 50 to 98% RH. Drying may be performed at a temperature of 45-80 ° C. for 15-30 hours.

In the assembly process, for example, the obtained negative electrode plate and positive electrode plate are stacked via the separator 13, and the current collecting portion of the electrode of the same polarity is welded with a strap to obtain an electrode group. This electrode group is disposed in a battery case to produce an unformed lead-acid battery. Next, dilute sulfuric acid is put into an unformed lead storage battery, and direct current is applied to form a battery. Subsequently, the lead storage battery 1 is obtained by adjusting the specific gravity (20 ° C.) of sulfuric acid after formation to an appropriate specific gravity of the electrolytic solution. The specific gravity (20 ° C.) of sulfuric acid used for formation may be 1.15 to 1.25. The specific gravity (20 ° C.) of sulfuric acid after formation is preferably 1.25 to 1.33, more preferably 1.26 to 1.30. The formation conditions and the specific gravity of sulfuric acid can be adjusted according to the size of the electrode. The chemical conversion treatment may be performed in the assembly process or may be performed in the electrode manufacturing process (tank formation).

Hereinafter, the present invention will be more specifically described by way of examples. However, the present invention is not limited to the following examples.

Example 1
(Preparation of battery case)
The battery case which consists of a box with an upper surface open | release, and the inside was divided into six cell rooms by the partition was prepared.

(Production of positive electrode)
With respect to the lead powder, 0.25 mass% (based on the total mass of the lead powder) of acrylic fiber as a reinforcing staple fiber was added and dry mixed. Next, 3% by mass of water and 30% by mass of dilute sulfuric acid (specific gravity 1.55) were added to the obtained mixture containing lead powder, and the mixture was kneaded for 1 hour to prepare a positive electrode active material paste. In preparation of the positive electrode active material paste, addition of dilute sulfuric acid (specific gravity 1.55) was performed stepwise in order to avoid a rapid temperature rise. In addition, the compounding quantity of water and dilute sulfuric acid is a compounding quantity on the basis of the total mass of lead powder and a staple for reinforcement.

The positive electrode active material paste was filled in an expanded current collector produced by subjecting a rolled sheet made of a lead alloy to expand processing, and then it was aged for 24 hours in an atmosphere with a temperature of 50 ° C. and a humidity of 98%. Then, it dried at the temperature of 50 degreeC for 16 hours, and produced the positive electrode which has an unformed positive electrode active material.

(Fabrication of negative electrode)
Lead powder was used as a raw material of the negative electrode active material. A mixture of sodium lignin sulfonate (trade name: Vanillex N, manufactured by Nippon Paper Industries Co., Ltd.) and furnace black (trade name: Vulcan XC, manufactured by Cabot Co., Ltd.) was added to lead powder and then dry mixed. Next, after adding water, it knead | mixed. Subsequently, while mixing little by little diluted sulfuric acid having a specific gravity of 1.280, the mixture was kneaded to prepare a negative electrode active material paste. In addition, content of lignin sulfonate sodium and a furnace black was mix | blended so that all might be 0.2 mass% on the basis of the total mass of the negative electrode active material after formation.

The negative electrode active material paste was filled in an expanded current collector made by expanding a rolled sheet made of a lead alloy, and then aged for 24 hours in an atmosphere with a temperature of 50 ° C. and a humidity of 98%. Thereafter, the resultant was dried to prepare a negative electrode having an unformed negative electrode active material.

(Assembly of battery)
An unformed negative electrode was inserted into a polyethylene separator processed into a bag shape. Next, five unformed positive electrodes and six unformed negative electrodes inserted in the bag-like separator were alternately laminated. Subsequently, the ear parts of the electrodes of the same polarity were welded to produce an electrode plate group by a cast-on-strap (COS) method. A Pb—Sn-based alloy (Pb content: 98 mass%, Sn content: 2 mass%) was used for the strap on the negative electrode side.

Six electrode plate groups were prepared, and inserted into the battery case to assemble an EN standard 12 V cell battery (rank performance: 370, size: LN2). At this time, as the lid, the lid having the exhaust chamber of the above-described embodiment shown in FIGS. 3 to 5 was used. Thereafter, a sulfuric acid solution with a specific gravity of 1.230 was injected, and formation was performed at a constant current of 10.4 A for 20 hours. The specific gravity of the electrolytic solution (sulfuric acid solution) after formation was adjusted to 1.28 (20 ° C.).

Example 2
A lead-acid battery was manufactured in the same manner as Example 1, except that scale-like graphite (manufactured by Nippon Graphite Industry Co., Ltd., trade name: ACB) was used instead of the furnace black in the preparation of the negative electrode. In addition, content of scale-like graphite was mix | blended so that it might be 1.5 mass% on the basis of the total mass of the negative electrode active material after formation.

Example 3
In the preparation of the negative electrode, Example 1 was used except that bisphenol-based resin (condensate of bisphenol, aminobenzene sulfonic acid and formaldehyde, Nippon Paper Industries Co., Ltd., trade name: Bisparz P 215) was used instead of sodium lignin sulfonate. A lead storage battery was produced in the same manner as in. In addition, content of bisphenol-type resin was mix | blended so that it might be 0.2 mass% on the basis of the total mass of the negative electrode active material after formation.

Example 4
A lead-acid battery was produced in the same manner as in Example 2 except that, in the preparation of the negative electrode, a bisphenol resin having the same type and amount as in Example 3 was used instead of sodium lignin sulfonate.

Comparative Example 1
Lead was prepared in the same manner as in Example 4 except that a Pb—Sb alloy (Pb content: 98 mass%, Sb content: 2 mass%) was used instead of the Pb—Sn alloy for the negative electrode side strap. A storage battery was made.

<Characteristics evaluation>
Below, liquid reduction suppression and DCA performance were evaluated about the lead storage battery of an Example and a comparative example. The results are shown in Table 1. In addition, evaluation of each performance was performed by relatively evaluating the measurement result of Comparative Example 1 as 100.

(Reduction of liquid)
A constant voltage overcharge was performed at 14.4 V for 42 days at an ambient temperature (water bath temperature) of 60 ° C. The liquid reduction suppression was evaluated by measuring the mass of the lead storage battery before and after this charge, and comparing the mass difference (the amount of liquid reduction due to overcharge (the amount of liquid reduction)). It can be said that the smaller the amount of liquid reduction, the better in terms of liquid reduction suppression.

(DCA performance)
The DCA performance was evaluated by an evaluation method according to the Dynamic Charge Acceptance (DCA) test described in EN standard BS EN 50342-6: 2015. The average current values during charging standardized by the conversion equation are compared, and the larger the average current value, the better the DCA performance.

DESCRIPTION OF SYMBOLS 1 ... Lead storage battery, 2 ... Battery case, 3 ... Lid, 4 ... 1st lid part, 5 ... 2nd lid part, 10 ... Electrode group, 11 ... Negative electrode, 12 ... Positive electrode, 22 ... Cell chamber, 400 ... Exhaust chamber components, D1, D2, D3, D4, D5, D6 ... exhaust chamber, h ... reflux hole.

Claims

A battery case having a cell chamber and having an open upper surface,
An electrode group and an electrolytic solution accommodated in the cell chamber;
And a lid closing the opening.
The lead storage battery, wherein the electrode group includes a plurality of negative electrodes and a plurality of positive electrodes, and the plurality of negative electrodes are connected by a strap formed of an alloy containing Pb and Sn.
The lid is a first lid, a second lid provided on the first lid, and an exhaust formed between the first lid and the second lid. Have a room,
The lead storage battery according to claim 1, wherein a reflux hole for refluxing the electrolytic solution into the cell chamber is provided on a bottom wall of the first lid part separating the exhaust chamber and the cell chamber.
The lead acid battery according to claim 1, wherein the negative electrode contains a resin having a structural unit derived from a phenolic compound.
The lead acid battery according to claim 3, wherein the structural unit comprises a structural unit derived from a bisphenol-based compound.
The lead acid battery according to claim 3, wherein the structural unit comprises a structural unit derived from lignin.
The lead-acid battery according to any one of claims 1 to 5, wherein the negative electrode contains a carbon material.
The lead acid battery according to claim 6, wherein the carbon material comprises carbon black.