lead-acid battery

Abstract

Lead-acid battery, including: a negative electrode material, wherein the negative electrode material contains an organic anti-shrinkage agent, and The organic anti-shrinkage agent is water-soluble and has an average particle size of not less than 0.1 µm and not more than 9 µm in sulfuric acid with a relative density of 1.25.

Description

[0001] The present invention relates to a lead-acid battery. STATE OF THE ART

[0002] A negative electrode material of a lead-acid battery contains an organic anti-shrinkage agent (expander), such as lignosulfonic acid or a sulfonated bisphenol condensation product. Patent document 1 JP H08-287916 A discloses that the high-rate discharge performance at low temperatures and the lifetime of a lead-acid battery can be improved by an organic anti-shrinkage agent. Patent document 1 suggests that lignosulfonic acid has a low molecular weight and is therefore readily eluted from a negative electrode plate into an electrolyte solution and oxidized at the positive electrode plate to escape.Patent document 1 discloses that when using a mixture of sulfonic acid salt of a styrene-divinylbenzene copolymer as a cation exchange resin and lignosulfonic acid, a suitable high-rate discharge performance at low temperature is maintained until the end of the lifetime due to the chemically stable sulfonic acid salt of the styrene-divinylbenzene copolymer.

[0003] Patent document 2 (JP 4 135 788 B2) discloses an additive for a lead-acid battery containing particulate lignin with a particle size of 0.01 to 0.8 µm. Patent document 2 indicates that the additive can reactivate a lead-acid battery that has been used for one year.

[0004] The S-element content of the organic anti-shrinkage agent refers to the content of sulfonic acid groups, and in this context, patent document 3 (JP 3 385 879 B2) indicates that fluctuations in high-rate discharge performance can be reduced when the sulfonation ratio of lignosulfonic acid is 90% or higher. Patent document 4 (JP 2013 - 41 848 A) suggests that using a bisphenol condensation product with an S-element content of 6 to 10 wt% instead of lignosulfonic acid improves charge acceptance. It is noted that this is due to the lower lead content compared to lignosulfonic acid. 2+ -This is due to the ion adsorption capacity of the bisphenol condensation product.

[0005] A sulfonation ratio of 90% in lignosulfonic acid is equivalent to approximately 3700 µmol / g in terms of the sulfur content per unit mass of the organic anti-shrinkage agent. A sulfur content of 6 to 10% by mass in the bisphenol condensation product is equivalent to 1875 µmol / g to 3125 µmol / g in terms of the sulfur content per unit mass of the organic anti-shrinkage agent.

[0006] Patent document 5 discloses an additive for a lead-acid battery to prevent a reduction in electrical capacity due to long-term use. Patent document 6 describes a method for producing a negative battery paste. DOCUMENTS ON THE STATE OF TECHNICAL PATENT DOCUMENTS Patent document 1: JP H08 - 287 916 A Patent document 2: JP 4 135 788 B2 Patent document 3: JP 3 385 879 B2 Patent document 4: JP 2013 - 41 848 A Patent document 5: JP 4 135 788 B2 Patent document 6: US 2003 0 180 613 A1 SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] Currently, a state in which lignosulfonic acid exists as a typical organic anti-shrinkage agent in a negative electrode plate is not clearly known. The present inventors found that lignosulfonic acid aggregates in sulfuric acid and thus exhibits a larger particle size in sulfuric acid than in neutral water. Accordingly, a discussion of the average particle size, average molecular weight, and the like of lignosulfonic acid in an environment other than sulfuric acid is of minor importance. It is understood that the lignosulfonic acid is present in contact with an electrolyte solution in a negative electrode plate. Furthermore, the present inventors found that the effect of lignosulfonic acid varies depending on the average particle size of the lignosulfonic acid in sulfuric acid.Furthermore, the present inventors found that the mean pore size of a negative electrode material varies depending on the average particle size of lignosulfonic acid in sulfuric acid. In other words, lignosulfonic acid with a large average particle size increases the mean pore size of a negative electrode material. The present inventors confirmed that the average particle size in sulfuric acid is also important for other organic anti-shrinkage agents. Thus, the present inventors found that by regulating the average particle size of an organic anti-shrinkage agent in sulfuric acid, the pore size of a negative electrode material can be regulated to control the properties of high-rate discharge at low temperatures and resistance to high temperatures, which led to the present invention.

[0008] One object of the present invention is to improve the original high-rate discharge performance at low temperature and to reduce the deterioration of the high-rate discharge performance at low temperature due to the effects of high temperatures.

[0009] Another object of the present invention is to reduce the resistance in a negative electrode material of a lead-acid battery.

[0010] An additional objective of the present invention is to improve the original value of the discharge power of 0.2 CA. MEANS TO SOLVENT THE PROBLEM

[0011] A feature of the lead-acid battery of the present invention is that a negative electrode material contains an organic anti-shrinkage agent which is water-soluble and has an average particle size of not less than 0.1 µm and not more than 9 µm in sulfuric acid with a relative density of 1.25.

[0012] Another feature of the lead-acid battery of the present invention is that a negative electrode material contains an organic anti-shrinkage agent which is water-soluble, and the organic anti-shrinkage agent, when extracted from the negative electrode material with an alkaline aqueous solution, has an average particle size of not less than 0.1 µm and not more than 9 µm in sulfuric acid with a relative density of 1.25.

[0013] Another feature of the lead-acid battery of the present invention is that a negative electrode material contains an organic anti-shrinkage agent which is water-soluble under neutral or basic conditions (pH: 7 or above), and the organic anti-shrinkage agent, when extracted from the negative electrode material with an alkaline aqueous solution, has an average particle size of not less than 0.1 µm and not more than 9 µm in sulfuric acid with a relative density of 1.25.

[0014] If the negative electrode material contains an organic anti-shrinkage agent with an average particle size of not less than 0.1 µm and not more than 9 µm in sulfuric acid with a relative density of 1.25, the mean pore size of the negative electrode material is, for example, 1.5 µm when the average particle size is 0.9 µm. The organic anti-shrinkage agent content is preferably not less than 0.05 wt% and not more than 0.5 wt% per 100 wt% of the negative electrode material.

[0015] The organic anti-shrinkage agent to be used is water-soluble. Alternatively, the organic anti-shrinkage agent to be used is water-soluble under neutral or alkaline conditions (pH 7 or above). A sulfonic acid salt of a styrene-divinylbenzene copolymer is not water-soluble and does not form aggregates. Specifically, the organic anti-shrinkage agent is, for example, lignosulfonic acid; however, it could be sulfomethylated Kraft lignin or a synthetic polymer anti-shrinkage agent, such as polyacrylamide tert-butylsulfonic acid. Such a component may be in the form of an acid or in the form of a salt, such as a sodium salt.

[0016] To measure the average particle size of the organic anti-shrinkage agent, an aqueous solution of organic anti-shrinkage agent with a concentration of 1 to 10 mg / ml by volume is diluted 20-fold with sulfuric acid having a relative density of 1.26, resulting in a sulfuric acid solution with a relative density of 1.25. The aqueous solution of organic anti-shrinkage agent is obtained by taking electrode material from a negative electrode plate of a lead-acid battery, washing the electrode material with water to remove sulfuric acid, and then dissolving the electrode material in an alkaline solution, such as 1.0 M (1 mol / l) aqueous sodium hydroxide (NaOH) solution, to extract the organic anti-shrinkage agent.The sample, obtained by diluting the aqueous solution of organic anti-shrinkage agent with sulfuric acid 20-fold, is measured while being stirred with a magnetic stirrer using a batch-type cell at 25°C in a laser diffraction / distribution particle size analyzer LA-950 V2, manufactured by HORIBA, Ltd., to determine the volume-based average particle size. Coexisting ions, such as lead ions, aluminum ions, and sodium ions, have only a minor influence on the measured value of the average particle size.

[0017] To determine the mean pore size of the negative electrode material, the pore size distribution is measured over a range of 0.01 µm to 1000 µm using a mercury penetration-type pore size distribution meter, and the volume-based mean value is calculated. The content of sulfonic acid groups in the organic anti-shrinkage agent is determined by performing a neutralization titration, while the electrical conductivity is measured using an aqueous solution of an organic compound previously prepared as an acid.

[0018] When lignosulfonic acid (hereinafter referred to as lignin) is hydrolyzed in sulfuric acid at high temperature, the particle size of the lignin in sulfuric acid can decrease ( Fig.1) It is found that the particle size of lignin in sulfuric acid can be reduced by increasing the number of hydrophilic functional groups, for example, hydroxyl groups, and that the molecular weight of the lignin does not significantly affect the particle size of the lignin in sulfuric acid. If lignin with a small average particle size is used in sulfuric acid, a negative electrode material with a small pore size is obtained, and if lignin with a large average particle size is used in sulfuric acid, a negative electrode material with a large pore size is obtained. Fig. 2) Using a negative electrode material with a small pore size results in high-rate discharge power at low temperatures. The pore size of the negative electrode material is regulated by the average particle size of lignin in sulfuric acid.

[0019] When sulfuric acid is added to an aqueous lignin solution, the lignin sediments to form a supernatant with low absorption, and the sedimented lignin exists in the form of aggregated colloids. This suggests that the particle size of the colloidal particles of the aggregated lignin is determined as a function of the sulfuric acid concentration ( Fig. 3).

[0020] When a lignin-containing sulfuric acid solution is heated, the particle size of the lignin increases ( Fig. 4) When a lead-acid battery is overcharged at high temperature, the pore size of the negative electrode material increases ( Fig.5) When the lead-acid battery is exposed to high temperatures through high-temperature overcharging, etc., the particle size of the lignin increases accordingly, and the pore size of the negative electrode material also increases. If lignin with a large particle size is used in sulfuric acid, the high-rate discharge performance at low temperatures is significantly reduced after exposure to high-temperature overcharging.

[0021] There is an optimal range for the average particle size of lignin, and the high-rate discharge performance at low temperature does not improve with lignin having an extremely small average particle size (Table 1 and Fig.6) Thus, the average particle size of lignin in sulfuric acid is not less than 0.1 µm and not more than 9 µm, more preferably not less than 0.4 µm and not more than 9 µm, most preferably not less than 0.4 µm and not more than 8 µm (Table 1, Table 2, Fig. 6 and Fig. 7).

[0022] Studies regarding lignin also apply to other organic anti-shrinkage agents, and if the average particle size in sulfuric acid is not less than 0.1 µm and not more than 9 µm, a lead-acid battery is obtained whose initial high-rate discharge performance at low temperature is excellent and which exhibits a small reduction in high-rate discharge performance at low temperature even when exposed to high temperatures (Table 3). For example, to reduce the average particle size of the organic anti-shrinkage agent in sulfuric acid, it is effective to increase the number of hydrophilic functional groups per monomer molecule or per backbone.

[0023] In the present invention, the average particle size of the organic anti-shrinkage agent in sulfuric acid is optimized to improve the original value of the high-rate discharge performance at low temperature (also referred to as high-rate performance at low temperature) and to reduce a reduction in the high-rate discharge performance at low temperature due to exposure to high temperature.

[0024] A feature of the present invention is a lead-acid battery comprising: a negative electrode plate; a positive electrode plate; and an electrolyte solution, wherein a negative electrode material contains an organic anti-shrinkage agent and the negative electrode material has a concentration of 0.3 mg / cm². 3 or contains more than one S-element in the organic shrinkage material.

[0025] A feature of the present invention is a negative electrode plate of a lead-acid battery, wherein the negative electrode plate comprises: a negative electrode material containing an organic anti-shrinkage agent; and a current collector, wherein the negative electrode material contains 0.3 mg / cm² 3 or contains more than one S-element in the organic anti-shrinkage agent.

[0026] Increasing the S-element content per unit volume of the negative electrode material reduces its resistance, leading to improved charge acceptance and improved high-rate discharge performance at low temperatures ( Fig. 12 and Table 9). A reduction in resistance can be observed when the S-element content of the negative electrode material is 0.3 mg / cm². 3or more, and a reduction in resistance can still be observed when the S-element content of the negative electrode material is 0.4 mg / cm² 3 or more. The dependence on the sulfur element content decreases at 1.5 mg / cm³. 3 or more, and decreases further at 2.3 mg / cm² 3 or more, and therefore the S element content is preferably 1.5 mg / cm³ 3 or less, in particular preferably 2.3 mg / cm² 3 Accordingly, the sulfur element content is preferably not less than 0.3 mg / m³. 3 and not more than 2.3 mg / cm² 3 , in particular preferably not more than 0.4 mg / cm² 3 and not less than 1.5 mg / cm² 3 The S element in the organic anti-shrinkage agent is crucial, and the S element in barium sulfate etc. is irrelevant for the present invention.

[0027] The present invention provides a lead-acid battery comprising: a negative electrode plate; a positive electrode plate; and an electrolyte solution, wherein the negative electrode material contains an organic anti-shrinkage agent and the sulfur content of the organic anti-shrinkage agent is 4000 µmol / g or more. The sulfur content is particularly preferably not less than 4000 µmol / g and not more than 6000 µmol / g, and most preferably not less than 4500 µmol / g and not more than 6000 µmol / g. An S-element content of not less than 4000 µmol / g and not more than 6000 µmol / g means that the S-element content of the organic anti-shrinkage agent is not less than 128 mg / g and not more than 192 mg / g, and an S-element content of 4500 µmol / g means that the S-element content of the organic anti-shrinkage agent is 144 mg / g.

[0028] The present invention provides a negative electrode plate for a lead-acid battery, the negative electrode plate comprising: a negative electrode material containing an organic anti-shrinkage agent; and a current collector, wherein the sulfur content of the organic anti-shrinkage agent is 4000 µmol / g or more. The sulfur content is particularly preferably not less than 4000 µmol / g and not more than 6000 µmol / g, and most preferably not less than 4500 µmol / g and not more than 6000 µmol / g.

[0029] When the amount of sulfur in the organic anti-shrinkage agent is increased, the initial value of the high-rate discharge performance at low temperature increases, and the ratio of the deterioration of the high-rate discharge performance at low temperature after the high-temperature durability test decreases when the sulfur element content is 4000 µmol / g or more (see Table 4, Table 5, Fig. 8 and Fig.9) Therefore, in the present invention, the S-element content of the organic anti-shrinkage agent is adjusted to 4000 µmol / g or more. - the original value of the high-rate discharge power at low temperature is improved, and - the ratio of high-rate discharge power at low temperature is reduced in a high-temperature resistance test.

[0030] Investigating the discharge time of 0.2 CA, where CA is a nominal capacity at a 5-hour discharge rate, shows that the discharge time of 0.2 CA improves until the amount of S reaches 6000 µmol / g. However, if the amount of S exceeds 6000 µmol / g, the discharge time of 0.2 CA decreases ( Fig.8 and Table 4). Thus, the sulfur element content of the organic anti-shrinkage agent is adjusted to not less than 4000 µmol / g and not more than 6000 µmol / g to improve the original discharge time value of 0.2 CA. The effect of the sulfur element in the organic anti-shrinkage agent is particularly high when the sulfur element content is 4500 µmol / g or more.

[0031] In lignosulfonic acid, it is not easy to adjust the sulfur content to 4000 µmol / g or above, and therefore it is preferred to use a synthetic organic anti-shrinkage agent, such as a bisphenol condensation product containing a sulfonic acid group, a sulfonyl group, or the like. However, a condensation product of a bisphenyl compound other than phenol, for example, a condensation product of N,N'-(sulfonyldi-4,1-phenylene)bis(1,2,3,4-tetrahydro-6-methyl-2,4-dioxopyrmidine-5-sulfonamide), can be used. For example, a condensation product containing formaldehyde, such as bisphenol A, S, or F, which contains a sulfonic acid group, can be used as a bisphenol condensation product, and bisphenol S has a sulfonyl group (-SO₂-) in addition to the sulfonic acid group, thus increasing the sulfur content.The sulfonic acid group does not have to be directly bonded to the phenyl group in a bisphenol, and, for example, as described in patent document 4, an alkyl chain can be bonded to a bisphenyl as an alkyl aminobenzenesulfonic acid.

[0032] The total content of the sulfur element in the organic anti-shrinkage agent is important, and groups containing a stable sulfur element in the negative electrode plate of the lead-acid battery include, for example, a sulfonic acid group and a sulfonyl group. Therefore, it is preferable for the sulfur element to be present as one of these groups. The performance as an organic anti-shrinkage agent depends only slightly on whether the sulfur element is present as a sulfonic acid group or as a sulfonyl group (see Table 7).

[0033] The mechanism by which the sulfur element content influences the high-rate discharge performance at low temperature and a discharge duration of 0.2 CA can be understood as follows. Particles of the organic anti-shrinkage agent are cross-linked to form colloidal particles, and electron-accepting and high-polarity groups, such as sulfonic acid and sulfonyl groups, can be present on the surfaces of the colloidal particles. As a result, the association of the organic anti-shrinkage agent is delayed, reducing the particle size of the colloidal particles. Consequently, the pore size of the negative electrode material in which the organic anti-shrinkage agent is dispersed is reduced.The present inventors determined the colloidal particle size of the organic anti-shrinkage agent and the pore size of the negative electrode material and confirmed that the pore size decreased with an increase in the S-element content (Table 6, . Fig. 10 and Fig. 11).

[0034] The present invention also has the following features: 1. A negative electrode plate of a lead-acid battery, wherein the negative electrode plate contains a negative electrode material, the negative electrode material contains an organic anti-shrinkage agent, and the organic anti-shrinkage agent is water-soluble and has an average particle size of not less than 0.1 µm and not more than 9 µm in sulfuric acid with a relative density of 1.25; 2. a negative electrode plate of a lead-acid battery, wherein the negative electrode plate contains a negative electrode material, the negative electrode material contains an organic anti-shrinkage agent, the organic anti-shrinkage agent is water-soluble, and the organic anti-shrinkage agent, after extraction from the negative electrode material with an aqueous alkaline solution, has an average particle size of not less than 0.1 µm and not more than 9 µm in sulfuric acid with a relative density of 1.25; 3. A negative electrode plate of a lead-acid battery, wherein the negative electrode plate contains a negative electrode material, the negative electrode material containing an organic anti-shrinkage agent, the organic anti-shrinkage agent being water-soluble under neutral or basic conditions (pH: 7 or more), and the organic anti-shrinkage agent, after extraction from the negative electrode material with a 1 M (1 mol / l) aqueous sodium hydroxide (NaOH) solution, having an average particle size of not less than 0.1 µm and not more than 9 µm in sulfuric acid with a relative density of 1.25; 4. the negative electrode plate of a lead-acid battery according to one of features 1 to 3, wherein the average particle size of the organic anti-shrinkage agent in sulfuric acid with a relative density of 1.25 is not less than 0.4 µm and not more than 9 µm; 5. the negative electrode plate of a lead-acid battery according to one of features 1 to 3, wherein the average particle size of the organic anti-shrinkage agent in sulfuric acid with a relative density of 1.25 is not less than 0.4 µm and not more than 8 µm; 6. the negative electrode plate of a lead-acid battery according to one of features 1 to 5, wherein the negative electrode material contains lignosulfonic acid hydrolyzed in sulfuric acid; 7. a method for producing the negative electrode plate of a lead-acid battery according to feature 6, wherein the lignosulfonic acid is hydrolyzed in sulfuric acid and subsequently introduced into the negative electrode material; 8. A negative electrode plate of a lead-acid battery, wherein the negative electrode plate contains a negative electrode material, the negative electrode material contains an organic anti-shrinkage agent, the negative electrode material contains an S-element in the organic anti-shrinkage agent, and the organic anti-shrinkage agent contains the S-element in an amount of 0.3 mg or more per unit volume (1 cm³). 3 ) of the negative electrode material; 9. the negative electrode plate of a lead-acid battery according to feature 8, wherein the organic anti-shrink agent contains the S-element in an amount of 0.4 mg or more per unit volume (1 cm³). 3 ) of the negative electrode material; 10. a negative electrode plate of a lead-acid battery, wherein the negative electrode plate contains a negative electrode material, wherein the negative electrode material contains an organic anti-shrinkage agent and the organic anti-shrinkage agent contains 4000 µmol / g or more of the sulfur element (S-element); 11. the negative electrode plate of a lead-acid battery according to one of features 8 to 10, wherein the content of the sulfur element (S-element) in the organic anti-shrinkage agent is not less than 4000 µmol / g and not more than 6000 µmol / g; 12. the negative electrode plate of a lead-acid battery according to one of features 8 to 10, wherein the content of the sulfur element (S-element) in the organic anti-shrinkage agent is not less than 4500 µmol / g and not more than 6000 µmol / g; 13. the negative electrode plate according to one of features 8 to 12, wherein the organic anti-shrinkage agent is a synthetic organic anti-shrinkage agent; 14. the negative electrode plate of a lead-acid battery according to one of features 8 to 13, wherein the organic anti-shrinkage agent contains an S-element consisting of at least one sulfonic acid group and one sulfonyl group; 15. the negative electrode plate of a lead-acid battery according to one of features 8 to 14, wherein the organic anti-shrinkage agent is a bisphenol condensation product containing a sulfur element (S element); 16. the negative electrode plate of a lead-acid battery according to one of features 1 to 15, wherein the mean pore size of the negative electrode material is not less than 0.3 µm and not more than 8.0 µm; 17. the negative electrode plate of a lead-acid battery according to one of features 1 to 15, wherein the mean pore size of the negative electrode material is not less than 0.6 µm and not more than 8.0 µm; 18. the negative electrode plate of a lead-acid battery according to one of features 1 to 15, wherein the mean pore size of the negative electrode material is not less than 0.6 µm and not more than 7.5 µm; 19. The negative electrode plate of a lead-acid battery according to any one of features 1 to 18, wherein the negative electrode material contains the organic anti-shrinkage agent in an amount of not less than 0.05 wt% and not more than 0.5 wt%.

[0035] In the description, the entire washed and dried electrode plate, from which a current collector has been removed, is an electrode material, and the electrode material contains additives such as a conductive material, a reinforcing material, and an anti-shrinkage agent. In one example, the electrode material is referred to simply as the active material, and the electrode material is identical to the active material. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a graphical representation showing the particle size distributions of expanders (organic anti-shrinkage agents) in sulfuric acid, where expander A corresponds to a conventional example and expander B corresponds to an example. Fig. Figure 2 is a graphical representation showing the relationships between the differential pore volume of a negative active material after formation and the type of expander. Fig.Figure 3 is a graphical representation showing the relationships between the amount of expander precipitated from an expander-sulfuric acid solution and the sulfuric acid concentration. Fig. Figure 4 is a graphical representation showing the particle size distributions of expanders A and B in sulfuric acid at 65°C and in sulfuric acid at 25°C. Fig. Figure 5 is a graphical representation showing the relationships between the differential pore volume of a negative active material after high-temperature overload and the type of expander. Fig. Figure 6 is a graphical representation showing relationships between the colloidal particle size of an organic anti-shrinkage agent in sulfuric acid and the high-rate discharge performance at low temperature. Fig.Figure 7 is a graphical representation showing the relationships between the colloidal particle size of an organic anti-shrinkage agent in sulfuric acid and the mean pore size of an active material. Fig. Figure 8 is a characteristic graphical representation showing the relationships between the S-element content in an organic anti-shrinkage agent and the original performance. Fig. Figure 9 is a characteristic graphical representation showing a relationship between the S-element content in an organic anti-shrinkage agent and the high-rate discharge performance at low temperature after a high-temperature overload. Fig. Figure 10 is a characteristic graphical representation showing a relationship between the S-element content in an organic anti-shrinkage agent and the mean pore size in a negative active material. Fig.Figure 11 is a characteristic graphical representation showing a relationship between the S-element content and the colloidal particle size in sulfuric acid in an organic anti-shrinkage agent. Fig. Figure 12 is a characteristic graphical representation that shows a relationship between the S-element content per unit volume and the resistance value in a negative active material. WAY AND WAY TO EXECUTIVE THE INVENTION

[0036] An optical example of the invention of the present application is shown below. In an embodiment of the invention of the present application, the example can be suitably modified according to the average knowledge of a person skilled in the art and the disclosure of the prior art. EXAMPLE Preliminary test

[0037] Lignosulfonic acid was hydrolyzed in sulfuric acid with a relative density of 1.25 to 160°C in an autoclave. The hydrolysis temperature was preferably 140°C or above. Lignosulfonic acid that was not hydrolyzed was designated Expander A, and Lignosulfonic acid that was hydrolyzed was designated Expander B. A lead powder as the main component, 0.1 wt% expander, 0.15 wt% carbon black, 0.3 wt% barium sulfate, and 0.1 wt% reinforcing material were formed into a paste with sulfuric acid such that it was incorporated into a negative electrode material, and a lead alloy grid was filled with the paste to obtain an unshaped positive electrode plate. A lead powder and 0.1 wt% of a reinforcing material were formed into a paste with sulfuric acid, and a lead alloy grid was filled with the paste to obtain an unshaped positive electrode plate.The negative electrode plate was wrapped with a polyethylene separator, and an electrolyte solution was added to create a reservoir, resulting in a filled lead-acid battery. The characteristics of the lead-acid battery were measured. The use of expanders with different average particle sizes in sulfuric acid is significant, and other conditions, particularly the presence / absence and content of barium sulfate and the presence / absence and content of carbon, such as soot, can be arbitrarily determined.

[0038] Fig. Figure 1 shows the particle size distributions of expanders A and B in sulfuric acid with a relative density of 1.25 at 25°C. The average bulk particle size was 0.9 µm for expander B and 10 µm for expander A.

[0039] Fig.Figure 2 shows the pore size distribution of a negative active material after formation. The mean pore size with respect to volume was 1.5 µm for expander B and 9.0 µm for expander A, and in expander B, which had a small particle size, the pore size of the active material was also small.

[0040] Fig.Figure 3 shows the relationship between the amount of precipitated expander and the sulfuric acid concentration when a sulfuric acid solution of each of expanders A and B was stirred and left to stand overnight. In expander A, sedimentation associated with aggregation began at a sulfuric acid concentration of approximately 0.8 M (mol / L), whereas in expander B, sedimentation did not occur until a sulfuric acid concentration of approximately 4 M (mol / L) was reached. This suggests that a lignin expander aggregates in sulfuric acid, and the particle size of the colloidal particles of aggregated lignin depends on the sulfuric acid concentration.

[0041] Fig.Figure 4 shows the particle size distributions of the expander in sulfuric acid with a relative density of 1.25 at 65°C. The average particle size was 15 µm for expander A and 3 µm for expander B. The average particle size of the expander increased at high ambient temperatures. When the pore size distribution of the negative active material was measured after a high-temperature overload test, in which a battery was charged for 20 days at 60°C, the values ​​shown in Fig. The results shown in Figure 5 were obtained. The pore size of the negative active material increased in both Expander A and Expander B, but Expander B exhibited a smaller pore size than Expander A.

[0042] This suggests that expander particles (colloidal particles of the aggregated organic anti-shrinkage agent) form a steric hindrance to prevent the disappearance of small pores. A performance test on a lead-acid battery revealed that expander B, which has a small average particle size, provides superior high-rate discharge performance at low temperatures and superior resistance to high-temperature overcharging than expander A, which has a large average particle size. Attempt 1

[0043] Lignin (lignosulfonic acid) with an average particle size of 0.05 µm to 10 µm in sulfuric acid was prepared by varying the hydrolysis time in the same manner as in the preliminary experiment. The lignin can be added in the form of the acid or in the form of a salt, such as sodium. Unhydrolyzed lignin (with an average particle size of 10 µm in sulfuric acid) was also provided. Using these lignins, 55D23-type lead-acid batteries were manufactured by a conventional process in the same manner as in the preliminary experiment. The lignin content in the negative active material was 0.1 wt%. The lignin content is preferably 0.05 wt% to 0.5 wt%. Each lead-acid battery was charged, and the duration of constant current discharge at 300 A was measured at -15°C and defined as the high-rate discharge duration at low temperature.The charging process at 2.4 A was then continued for 10 days in a water bath at 60°C. The high-rate discharge time at low temperature was subsequently measured again, and the ratio of these times was defined as the initial low-temperature capacity retention ratio. Furthermore, the pore size distribution of the negative active material was measured after the high-temperature overload test, and the volume-based mean was determined. The results are shown in Table 1 and Table 2. The colloidal particle size in each table corresponds to the average particle size in sulfuric acid with a relative density of 1.25, and the colloidal particle size in Table 2 corresponds to the value before the high-temperature overload test. [Table 1] Table 1 Initial HR performance at low temperature Colloidal particle size / µm 0,05 0,1 0,4 0,8 1,6 3 6 8 10 High-rate discharge time at low temperature / s 130 180 195 202 212 220 215 208 195 Original mean pore size of the active material / µm 0,15 0,3 0,6 1,2 1,8 3 6 7,5 9 [Table 2] Table 2 HR performance at low temperature after high-temperature overload Colloidal particle size / µm 0,05 0,1 0,4 0,8 1,6 3 6 8 10 High-rate discharge time at low temperature / s 111 155 166 174 187 194 176 156 137 Original capacity retention rate / % 85 86 85 86 88 88 82 75 70 Average pore size of the active material / µm 0,3 0,6 1,6 2,8 4,7 7,6 13 16 19

[0044] From Table 1 and Fig. In section 6, it was shown that with an average particle size of lignin in sulfuric acid of 9 µm or less, the high-rate discharge time at low temperature increases, and this feature is maintained down to an average particle size of 0.1 µm, more preferably 0.4 µm. From Table 2 and Fig.In section 7, it was shown that with an average lignin particle size in sulfuric acid of 9 µm or less, the reduction ratio of the high-rate discharge time at low temperature can be reduced by applying high-temperature overload. Furthermore, it was found that the average lignin particle size in sulfuric acid can be reduced to decrease the mean pore size of the active material after exposure to high-temperature overload.It has been found that with an average particle size of lignin in sulfuric acid of not less than 0.1 µm and not more than 9 µm, more preferably of not less than 0.4 µm and not more than 9 µm, most preferably of not less than 0.4 µm and not more than 8 µm, higher performance is achieved than with an average particle size of lignin in sulfuric acid of 10 µm or above, either for the original value of the high-rate discharge performance at low temperature or after exposure to high-temperature overload. Organic anti-shrinkage agents other than lignin

[0045] Investigations were carried out regarding the following three synthetic organic anti-shrinkage agents: Polyacrylic acid (average molecular weight: 100,000; average particle size of 25 µm in sulfuric acid with a relative density of 1.25); Polymerization product of the sodium salt of polyacrylamide tert-butylsulfonic acid (ATBS polymer: ATBS is a registered trademark); and sulfomethylated kraft lignin.

[0046] Regarding the polymerization product of the sodium salt of polyacrylamide tert-butylsulfonic acid (ATBS polymer), three products with mean molecular weights of 50,000, 75,000, and 100,000 exhibited mean particle sizes of 8.0 µm, 6.0 µm, and 4.0 µm, respectively, in sulfuric acid with a relative density of 1.25. Thus, the decreasing order of magnitude of the mean particle size was inversely proportional to that of the molecular weight. In the ATBS polymer, the ratio of the backbone to the sulfonic acid groups was 1:1.

[0047] Sulfomethylated kraft lignin is obtained by adding formaldehyde and a sulfite to kraft lignin and treating the mixture under pressure at high temperature. In sulfomethylated kraft lignin, a sulfonic acid group (of the H-type or Na-type) is introduced as -CH₂-SO₃H(Na) via a methylene group. Sulfomethylated kraft lignin differs from conventional ligninsulfonic acid in the position of the sulfonic acid group. The amount of sulfonic acid groups per basic backbone was regulated to fall into the range of 0.05 to 0.4 by changing the amounts of formaldehyde and a sulfite, i.e., the conditions for sulfomethylation with an average molecular weight set to 12,000, so that the average particle size in sulfuric acid with a relative density of 1.25 was regulated to fall into the range of 1.4 µm to 17.0 µm.

[0048] With the exception that, instead of conventional lignosulfonic acid, 0.1 wt% of each of the aforementioned organic anti-shrinkage agents was included in the negative active material, the same procedure as in the preliminary test and the trial was carried out to produce a lead-acid battery, and the initial high-rate discharge power at low temperature and the value after the high-temperature overload test were determined. The results are shown in Table 3 along with data from the conventional example using lignosulfonic acid (lignin). [Table 3] Table 3 Colloidal particle size of each organic component and electrode power Name of the substance Lignosulfonic acid Polyacrylic acid ATBS sodium polymerization product * Sulfomethylated Kraft Lignin ** Average molecular weight 13000 1000000 50000 75000 100000 12000 12000 12000 12000 12000 12000 Quantity of sulfonic acid groups compared to basic backbone 0,13 - 1 1 1 0,05 0,08 0,1 0,15 0,25 0,4 Colloidal particle size / µm 10,0 25,0 8,0 6,0 4,0 17,0 14,0 12,0 8,0 4,2 1,4 High-rate discharge time at low temperature (originally) / s 195 188 211 213 219 135 152 178 212 218 216 High-rate discharge time at low temperature (after overcharging) / s 137 85 156 177 191 74 91 121 161 187 192 Original capacity retention ratio / % 70 45 74 83 87 55 60 68 76 86 89 Original mean pore size of inactive material / µm 9 >20 7,0 5,6 4,1 18,5 13,5 11,0 7,0 4,3 1, 9 * ATBS is a registered trademark.** Sulfomethylated kraft lignin is obtained by sulfonating kraft lignin with formaldehyde and a sulfite and differs from conventional lignosulfonic acid at the position of the sulfonic acid group.

[0049] In each organic anti-shrinkage agent, the average particle size in sulfuric acid with a relative density of 1.25 was adjusted to 9 µm or less to achieve the following effect: - High-rate discharge performance at low temperatures can be improved; and - even after exposure to high temperature overcharging, the high-rate discharge power at low temperature is high, and the high-rate discharge power retention ratio at low temperature can increase. Experiment 2: Production of the lead-acid battery

[0050] A lead powder, an organic anti-shrinkage agent consisting of a bisphenol condensation product, carbon black, barium sulfate, and a synthetic fiber-reinforcing material were mixed in water and sulfuric acid to obtain a negative active material paste. The resulting negative active material (more precisely, a negative electrode material) contained 0.15 wt% of the organic anti-shrinkage agent, 0.2 wt% carbon black, 1.0 wt% barium sulfate, and 0.05 wt% of the synthetic fiber-reinforcing material. Preferred concentrations of each component are as follows: the organic anti-shrinkage agent content is not less than 0.08 wt% and not more than 0.25 wt%, and the carbon black content is 1.0 wt% or less, or the carbon black can be omitted or replaced by another carbon, such as lamellar graphite.Preferably, the barium sulfate content is not less than 0.5 wt% and not more than 2.0 wt%, and the synthetic fiber-reinforcing material content is not less than 0.03 wt% and not more than 0.2 wt%. An expanded grid consisting of a Pb-Ca-Sn-based alloy was filled with a paste of negative active material, and drying and curing were carried out to obtain an unshaped negative electrode plate.

[0051] In this example, a condensation product of sulfonic acid group-containing bisphenol A with formamide and a condensation product of sulfonic acid group-containing bisphenol S with formaldehyde were used as organic anti-shrinkage agents. The conditions for sulfonation were further intensified, increasing the average number of sulfonic acid groups per bisphenol molecule compared to the initial reaction. Sulfonation was carried out after condensation of the mixture of bisphenols A, F, and S. In this way, the sulfur content was adjusted to a range of 3000 µmol / g to 7500 µmol / g. One condensation product derived from bisphenol A contains one sulfonic acid group, and another derived from bisphenol A contains one sulfonic acid group and one sulfonyl group. Additionally, a lignosulfonic acid with a sulfur content of 600 µmol / g was provided as a comparison.The type of lead powder, the manufacturing conditions, the red lead content, and so on can be determined arbitrarily, and a third component, such as a very small amount of the element Sb, can also be added.

[0052] Lead powder and a synthetic fiber-reinforcing material (0.1 wt% based on the amount of positive active material formed) were mixed in water and sulfuric acid to obtain a positive active material paste. An expanded grid made of a Pb-Ca-Sn-based alloy was filled with the paste, and drying and curing were carried out to obtain an unshaped positive electrode plate.

[0053] A cell was formed from five negative electrode plates and four positive electrodes, with the negative electrode plates surrounded by a microporous, bag-shaped polyethylene separator. The cell was contained within a polypropylene container, resulting in a liquid-type vehicle battery. The nominal capacity at a 5-hour discharge rate (CA) is 26 Ah, and the voltage is 12 V. The battery is not limited to automotive use and can be used anywhere. It can be either a liquid-type or a valve-regulated battery. Measurement methods

[0054] The organic anti-shrinkage agent content and the sulfur element content in the negative active material, as well as the pore size of the negative electrode material, are measured as follows. A fully charged lead-acid battery is disassembled, a negative electrode plate is removed and washed with water to remove the sulfuric acid component, and its dry weight is measured. An active material is separated from the negative electrode plate and immersed in a 1 mol / L aqueous sodium hydroxide (NaOH) solution to extract an organic anti-shrinkage agent. The anti-shrinkage agent content is determined using a previously prepared calibration curve and absorbance obtained with an ultraviolet / visible (UV / Vis) absorption spectrometer. The aqueous sodium hydroxide (NaOH) solution of the organic anti-shrinkage agent obtained by extraction from the active material is desalted, concentrated, and dried.A sulfur element in 0.1 g of the organic shrinkage agent is converted to sulfuric acid using an oxygen combustion piston method. The eluate is titrated with barium perchlorate, using thorin as an indicator to determine the titer, and the sulfur element content in the organic shrinkage agent is calculated from the titer. For the dried negative active material, the pore size distribution is determined by a mercury penetration method, and the volume-based mean is defined as the mean pore size. Here, areas with a measured pore size of 100 µm or above are considered gaps between active material particles rather than pores and are not included within the pores. The volume of the active material is determined by subtracting the volume of the pores with a measured pore size of 100 µm or above from the apparent volume. Performance of the lead-acid battery

[0055] For each lead-acid battery, the initial high-rate discharge power at low temperature (time (seconds) required for the terminal voltage to decrease to 6.0 V at a discharge current of 150 A at -15°C) and the time required for the terminal voltage to decrease to 10.5 V at a discharge current of 0.2 CA were measured. The results are presented in Fig. 8 and Table 4 shown. [Table 4] Table 4 Relationships between the S-element content in the organic shrinkage agent and the original performance S element content / µmol / g 3000 3500 4000 4500 5000 5500 6000 6500 7000 7500 600* High-rate discharge time at low temperature / s 150 162 170 178 185 188 195 197 200 200 153 Discharge time of 0.2 CA / h 4,8 5,4 6,0 6,3 6,5 6,4 5,6 4,8 4,2 4,0 4,8 * The sample with an S-element content of 600 µmol / g consists of lignosulfonic acid and is shown as a comparison example.

[0056] The high-rate discharge power at low temperature increased with increasing sulfur content, reaching an upper limit of approximately 200 seconds. Above 6000 µmol / g sulfur content, the high-rate discharge power no longer increased significantly, even with further increases in sulfur content. The discharge time of 0.2 CA was high at sulfur content levels between 4000 µmol / g and 6000 µmol / g, and reached its maximum at sulfur content levels between 4500 µmol / g and 5500 µmol / g.

[0057] The lead-acid battery, whose initial characteristics had been determined, was subjected to a high-temperature overcharge by a charge of 2.5 A for 240 hours at 65°C, and the high-rate discharge power at low temperature was subsequently measured. The ratio of the high-rate discharge power at low temperature after a high-temperature overcharge to the initial value of the high-rate discharge power at low temperature is shown in Fig. 9 and Table 5 shown. [Table 5] Table 5 - HR performance at low temperature after high-temperature overload S element content / µmol / g 3000 3500 4000 4500 5000 5500 6000 6500 7000 7500 600* High-rate discharge time at low temperature / s 75 102 128 142 167 173 185 187 190 192 77 Discharge time-retention ratio / % 50 63 75 80 90 92 95 95 95 96 50 * The sample with an S-element content of 600 µmol / g consists of lignosulfonic acid and is shown as a comparison example.

[0058] It was shown that increasing the S-element content improves the high-rate discharge performance at low temperature after a high-temperature overload and increases the discharge time retention ratio.

[0059] These results showed that when the organic anti-shrinkage agent contains a larger amount of sulfur than before, the sulfur content is in such a range that - both the original high-rate discharge performance at low temperature and the high-rate discharge performance at low temperature after a high-temperature overload can be improved, and - the discharge time can be increased by 0.2 CA. The sulfur content in the organic anti-shrink agent must be between 4000 µmol / g and 6000 µmol / g. If the sulfur content is between 4500 µmol / g and 6000 µmol / g, the resulting lead-acid battery will exhibit excellent performance in both high-rate discharge at low temperatures and high-rate discharge at low temperatures after high-temperature overcharging.

[0060] The pore size distribution of the formed negative active material was measured. The same negative electrode plate as the one used in the lead-acid battery performance test was fabricated, a negative active material was separated from the formed negative electrode plate, and the pore size distribution was measured using a mercury penetration method. The organic anti-shrinkage agent was dispersed at a concentration of 0.002 wt% in sulfuric acid with a relative density of 1.25 at 25°C to obtain a colloidal solution, and the colloidal particle size distribution was measured using a laser light scattering method. The volume-based mean pore size versus the sulfur element content is calculated in [reference missing]. Fig. Figure 10 shows that the average volume-based colloidal particle size versus the S-element content is calculated in Fig.11 shown, and both are shown together in Table 6. [Table 6] Table 6: S-element content versus mean pore size of the negative active material and colloidal particle size of the organic anti-shrinkage agent in sulfuric acid S element content / µmol / g 3000 3500 4000 4500 5000 5500 6000 6500 7000 7500 600* Average pore size of the active material (original) / µm 13,0 8,0 7,0 4,5 1,2 1,1 0,6 0,4 0,2 0,1 12 Colloidal particle size (25°C) / µm 12 7,9 6,7 4,0 1,0 0,8 0,5 0,1 <0,1 <0,1 10 * The sample with an S-element content of 600 µmol / g consists of lignosulfonic acid and is shown as a comparison example.

[0061] When the sulfur content was increased, the colloidal particle size and the mean pore size decreased. Sulfuric acid groups or sulfonyl groups with high polarity and electron acceptance can be present on the surfaces of the colloidal particles, and when the concentration of these groups is increased, the electrostatic repulsion between the sulfonyl groups, etc., is enhanced. Therefore, it can be assumed that the colloidal particle size of the organic anti-shrinkage agent decreased with increasing sulfur content. The particle size of the organic anti-shrinkage agent can affect the pore size distribution of the negative active material, since the organic anti-shrinkage agent is dispersed in the negative active material, and it can be assumed that the pore size decreased with decreasing the colloidal particle size of the organic anti-shrinkage agent.It can be observed that by reducing the pore size compared to before, both the original high-rate discharge performance at low temperature and the high-rate discharge performance at low temperature after high-temperature overload improved, and the discharge time of 0.2 CA changed under the influence of the pore size.

[0062] The sulfur element in the organic anti-shrinkage agent can be present as a sulfonic acid group or as a sulfonyl group. By changing the ratio of bisphenol A and bisphenol S to the sulfur element content in the organic anti-shrinkage agent, which is set at 5000 µmol / g, the ratio of the sulfur element content derived from sulfonyl groups to the sulfur element content derived from sulfonic acid groups changed. The results in this case are shown in Table 7. The results did not depend significantly on whether the sulfur element was derived from a sulfonyl group or from a sulfonic acid group. The same results were obtained even when the sulfur element content was changed by condensation and sulfonation while simultaneously changing the mixing ratio of bisphenols A, S, and F. [Table 7] S element content / µmol / g 5000 Sulfonyl group-derived sulfur element content / µmol / g 700 1400 2100 Content of sulfonic acid group-derived S-element / µmol / g 4300 3600 2900 Original high-rate discharge time duration at low temperature / s 186 185 189 Discharge time of 0.2 CA / h 6,5 6,5 6,5 High-rate discharge time at low temperature after high-temperature overcharge / s 169 167 170 Discharge time-retention ratio / % 91 90 90 Colloidal particle size (25°C) / µm 1,0 1,0 1,0 Concentration of the organic anti-shrinkage agent

[0063] The concentration of the organic anti-shrinkage agent in the negative active material is preferably not less than 0.08 wt% and not more than 0.20 wt%. The results of varying the concentration of the organic anti-shrinkage agent in three steps—0.10 wt%, 0.15 wt%, and 0.20 wt%—using the organic anti-shrinkage agent in the middle row of Table 7 (the sulfur element content is 5000 µmol / g, the sulfonyl-derived sulfur element content is 1400 µmol / g, and the sulfonic acid-derived sulfur element content is 3600 µmol / g) are shown in Table 8. Both the initial low-temperature high-rate discharge performance and the low-temperature discharge performance after high-temperature overload improved slightly with increasing anti-shrinkage agent concentration, but the difference was not statistically significant.The duration of the discharge 0.2 CA did not depend on the concentration of the organic anti-shrinkage agent. [Table 8] Table 8 S-E element content / µmol / g 5000 Sulfonyl group-derived sulfur element content / µmol / g 1400 Content of sulfonic acid group-derived S-element / µmol / g 3600 Salary / Mass % 0,10 0,15 0,20 Original high-rate discharge time duration at low temperature / s 182 185 188 Discharge time of 0.2 CA / h 6,5 6,5 6,5 High-rate discharge time at low temperature after high-temperature overcharge / s 155 167 169 Discharge time duration - Retention ratio / % 85 90 90 Colloidal particle size (25°C) / µm 1,0 1,0 1,0

[0064] S-element content per unit volume of negative active material

[0065] It was observed that increasing the S-element content per unit volume of the negative active material decreased its resistance. Changing the density of the negative active material paste altered its density after formation within a range of 2.8 g / cm³. 3 up to 3.8 g / cm³ 3The concentration of the organic anti-shrinkage agent in the negative active material varied within a range of 0.08 wt% to 0.25 wt%, and the sulfur element content of the organic anti-shrinkage agent varied within a range of 600 µmol / g to 7000 µmol / g. The resistance value of the fully charged negative active material was determined using a four-wire measurement method, while the sulfur element content per unit volume of the negative active material was determined as described above within a range of 0.15 mg / cm³. 3 up to 2.5 mg / cm² 3 was changed. The results are in Fig. Figure 12 and Table 9 show that a synthetic organic anti-shrinkage agent consisting of a bisphenol condensation product was used, with the exception of the conventional example in which lignin (S-element content 600) was used. jimol / g) was used. Resistance is indicated by a relative value based on the value in the comparison example, which is set to 100%. [Table 9] Table 9 Conventional Example S-element content (mg / cm³) 3 ) 0,15 0,2 0,3 0,4 0,8 1 1,5 2 2,3 2,5 Total amount of S in the molecule (µmol / g) 600 1500 3000 4000 4500 4000 6000 6000 7000 7000 Content of the anti-shrinkage agent in inactive material (mass %) 0,2 0,1 0,08 0,08 0,15 0,2 0,2 0,25 0,25 0,25 Resistance of the active material* 100 99 97 96 93,5 92,5 91 90 89,8 89,6 * Relative value based on the value in the conventional example, which is set to 100.

[0066] Increasing the sulfur element content per unit volume of the negative active material decreases the resistance, leading to improved charge acceptance and high-rate discharge performance at low temperatures. Results obtained by varying the type of organic anti-shrinkage agent, the concentration of the sulfur element in the organic anti-shrinkage agent, and the concentration of the organic anti-shrinkage agent showed that the resistance depended solely on the sulfur element content, as shown in Fig. 12 shown.

[0067] Fig.Figures 12 and Table 9 show that with an S-element content of the negative active material of 0.3 mg / cm³ 3 or more significantly reduces the resistance of the negative active material, and if the S-element content is 0.4 mg / cm³ 3 The resistance decreases further as the sulfur content increases. The dependence on the sulfur element content decreases at 1.5 mg / cm³. 3 or above, and decreases further at 2.3 mg / cm² 3 or more. Accordingly, the sulfur element content is preferably 1.5 mg / cm³. 3 or below, in particular preferably 2.3 mg / cm² 3 or below. The total sulfur content is preferably not less than 0.3 mg / cm³. 3 and not more than 2.3 mg / cm² 3 , in particular preferably not more than 0.4 mg / cm² 3 and not less than 1.5 mg / cm² 3 . Addition

[0068] Bisphenol A and bisphenol S are used in the example; however, a condensation product of sulfonated bisphenol F or the like can be used. It is not necessary for the sulfonic acid group and the sulfonyl group to be directly bonded to the phenyl group in a bisphenol, and, as mentioned in Patent Document 2, an alkyl chain, etc., can be bonded to a bisphenol as an alkyl aminobenzenesulfonic acid, etc. The organic anti-shrinkage agent is not limited to a bisphenol condensation product containing a sulfonic acid group, a sulfonyl group, or the like, and, for example, N,N'-(sulfonyldi-4,1-phenylene)bis(1,2,3,4-tetrahydro-6-methyl-2,4-dioxopyrimidine-5-sulfonamide) can be used. Furthermore, the sulfonic acid group can be in the form of an acid or in the form of a salt, such as a sodium salt.

[0069] The bisphenol condensation product contains a large number of hydroxyl groups, which are further polarized under the influence of sulfonyl and sulfonic acid groups. This increases the charge density on the surfaces of the colloidal particles containing the anti-shrinkage agent. As the charge density increases, the particle size of the colloidal particles decreases. Consequently, the average pore size decreases, the high-rate discharge performance at low temperatures improves, and the discharge time of 0.2 CA changes.

Claims

[1] Lead-acid battery, comprising: a negative electrode material, wherein the negative electrode material contains an organic anti-shrinkage agent, and The organic anti-shrinkage agent is water-soluble and has an average particle size of not less than 0.1 µm and not more than 9 µm in sulfuric acid with a relative density of 1.

25. [2] Lead-acid battery, comprising: a negative electrode material, wherein the negative electrode material contains an organic anti-shrinkage agent, the organic anti-shrinkage agent is water-soluble and The organic anti-shrinkage agent, after extraction from the negative electrode material with an aqueous alkaline solution, has an average particle size of not less than 0.1 µm and not more than 9 µm in sulfuric acid with a relative density of 1.

25. [3] Lead-acid battery, comprising: a negative electrode material, wherein the negative electrode material contains an organic anti-shrinkage agent, the organic anti-shrinkage agent is water-soluble under neutral or alkaline conditions (pH: 7 or more) and The organic anti-shrinkage agent, after extraction from the negative electrode material with a 1 M (1 mol / l) aqueous sodium hydroxide (NaOH) solution, exhibits an average particle size of not less than 0.1 µm and not more than 9 µm in sulfuric acid with a relative density of 1.

25. [4] Lead-acid battery according to any one of claims 1 to 3, wherein the average particle size of the organic anti-shrinkage agent in sulfuric acid with a relative density of 1.25 is not less than 0.4 µm and not more than 9 µm. [5] Lead-acid battery according to any one of claims 1 to 3, wherein the average particle size of the organic anti-shrinkage agent in sulfuric acid with a relative density of 1.25 is not less than 0.4 µm and not more than 8 µm. [6] Lead-acid battery according to any one of claims 1 to 5, wherein the negative electrode material contains lignosulfonic acid hydrolyzed in sulfuric acid. [7] Method for producing the lead-acid battery according to claim 6, wherein the lignosulfonic acid is hydrolyzed in sulfuric acid and subsequently introduced into the negative electrode material. [8] Lead-acid battery, comprising: a negative electrode plate; a positive electrode plate; and an electrolyte solution, wherein the negative electrode plate contains a negative electrode material, the negative electrode material contains an organic anti-shrinkage agent, the negative electrode material contains a sulfur element (S-element) in the organic anti-shrinkage agent and the organic anti-shrink agent contains the sulfur element (S-element) in an amount of 0.3 mg or more per unit volume (1 cm³). 3 ) of the negative electrode material. [9] Lead-acid battery according to claim 8, wherein the organic anti-shrinkage agent contains the sulfur element (S-element) in an amount of 0.4 mg or more per unit volume (1 cm³). 3 ) of the negative electrode material. [10] Lead-acid battery, comprising: a negative electrode plate; a positive electrode plate; and an electrolyte solution, wherein the negative electrode plate contains a negative electrode material, the negative electrode material contains an organic anti-shrinkage agent, and the organic anti-shrinkage agent contains 4000 µmol / g or more of the sulfur element (S element). [11] Lead-acid battery according to any one of claims 8 to 10, wherein the sulfur element (S-element) content in the organic anti-shrink agent is not less than 4000 µmol / g and not more than 6000 µmol / g. [12] Lead-acid battery according to any one of claims 8 to 10, wherein the sulfur element (S-element) content in the organic anti-shrink agent is not less than 4500 µmol / g and not more than 6000 µmol / g. [13] Lead-acid battery according to any one of claims 8 to 12, wherein the organic anti-shrink agent is a synthetic organic anti-shrink agent. [14] Lead-acid battery according to any one of claims 8 to 13, wherein the organic anti-shrinkage agent comprises an S-element consisting of at least one sulfonic acid group and one sulfonyl group. [15] Lead-acid battery according to any one of claims 8 to 14, wherein the organic anti-shrink agent is a bisphenol condensation product containing a sulfur element (S element). [16] Lead-acid battery according to any one of claims 1 to 15, wherein the mean pore size of the negative electrode material is not less than 0.3 µm and not more than 8.0 µm. [17] Lead-acid battery according to any one of claims 1 to 15, wherein the mean pore size of the negative electrode material is not less than 0.6 µm and not more than 8.0 µm. [18] Lead-acid battery according to any one of claims 1 to 15, wherein the mean pore size of the negative electrode material is not less than 0.6 µm and not more than 7.5 µm. [19] Lead-acid battery according to any one of claims 1 to 18, wherein the negative electrode material contains the organic anti-shrink agent in an amount of not less than 0.05 wt% and not more than 0.5 wt%.

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