Lead-acid battery

Abstract

The present invention addresses the problem in which when a lead-acid battery is used in a low temperature region, said lead-acid battery having a plurality of cell chambers arranged along the lamination direction of laminates constituting electrode plate groups housed in the cell chambers, the negative electrode plates constituting the electrode plate groups stored in the cell chambers at both ends in the lamination direction are more easily affected by low temperatures than the negative electrode plates constituting the electrode plate groups stored in the cell chambers other than the cell chambers at both ends in the lamination direction, and thus high rate electrical discharge performance of the lead-acid battery itself may become insufficient.　The present invention is characterized in that the BET specific surface area X of the negative electrode plates of the laminates constituting the electrode plate groups housed in the cell chambers at both ends in the lamination direction is 1.00 m2 / g or less, the BET specific surface area Y of the negative electrode plates constituting the electrode plate groups housed in the cell chambers other than the cell chambers at both ends in the lamination direction is at least 0.50 m2 / g and less than 1.00 m2 / g, and the ratio of X / Y is more than 1.00 and at most 1.60.

Description

lead acid battery

[0001] The present invention relates to a lead-acid battery.

[0002] In recent years, automotive lead-acid batteries have been subjected to increasingly harsh operating conditions due to the increasing number of electrical components and improved fuel economy. Therefore, automotive lead-acid batteries are required to withstand such harsh conditions. In particular, idle-stop vehicles (ISS vehicles) have rapidly become widespread. In ISS vehicles, the engines are started frequently, resulting in repeated high-current discharges from the lead-acid battery. In such cases, if the high-rate discharge performance of the lead-acid battery is insufficient, the battery voltage may drop when restarting the engine after an idle-stop, making it impossible to restart. In particular, the high-rate discharge performance of the battery deteriorates in low-temperature environments, making the above-mentioned problem more pronounced. Therefore, improving the high-rate discharge performance at low temperatures has become an important issue in recent years, so that batteries can be used in low-temperature regions where temperatures are below freezing.

[0003] For example, Patent Document 1 describes a plate pack pressure of 50.0 kg / dm ２ or more, and the specific surface area of ​​the active material is 5.0 m ２ / g to 8.0m ２ / g, and 0.80 m for negative electrode active material ２ / g to 1.4m ２ / g, it is possible to achieve both output characteristics during low-temperature rapid discharge and deep discharge life characteristics. Furthermore, it is stated that the battery output tends to increase with an increase in the specific surface area of ​​the active material in both the negative and positive electrodes.

[0004] However, in a lead-acid battery having multiple cell chambers arranged along the stacking direction of the stack of plates housed in the cell chambers, the negative plates of the plate assembly housed in the cell chambers at both ends of the stacking direction, which are more susceptible to the effects of the outside air, are more susceptible to the effects of low temperatures than the negative plates of the plate assembly housed in the cell chambers other than the ends of the stacking direction. Therefore, in low-temperature regions, the high-rate discharge performance of the cells at both ends of the stacking direction is lower than that of the cells other than the ends of the stacking direction, and the high-rate discharge performance of the lead-acid battery itself may become insufficient.

[0005] Japanese Patent Application Laid-Open No. 2003-338312

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a lead-acid battery having excellent high-rate discharge performance, particularly a lead-acid battery having excellent high-rate discharge performance at low temperatures so that it can be used in low-temperature regions.

[0007] In order to solve the above problems, one aspect of the present invention is a lead-acid battery having the following configurations (a) to (e): (a) a battery case having a plurality of cell chambers separated by partition walls, and a plate assembly housed in each of the plurality of cell chambers; (b) the plate assembly has a stack of a plurality of alternately arranged positive and negative plate sheets and a separator disposed between the positive and negative plate sheets, and the plurality of cell chambers are arranged along the stacking direction of the stack; (c) the BET specific surface area X of the negative plate constituting the plate assembly housed in the cell chambers at both ends of the stacking direction of the stack is 1.00 m ２ (d) The BET specific surface area Y of the negative electrode plate constituting the electrode plate group housed in the cell chamber other than both ends of the stacking direction of the laminate is 0.50 m ２ / g or more 1.00m ２ (e) The ratio X / Y is greater than 1.00 and equal to or less than 1.60.

[0008] In the lead-acid battery according to the present invention, the BET specific surface area X of the negative electrode plate constituting the electrode plate group housed in the cell chamber at both ends of the stacking direction of the stack is 1.00 m ２ / g or less, and the BET specific surface area Y of the negative electrode plate constituting the electrode plate group housed in the cell chamber other than both ends of the stacking direction of the stack is 0.50 m ２ / g or more 1.00m ２ / g and the ratio X / Y is greater than 1.00 and not greater than 1.60, the high-rate discharge performance of the cells at both ends in the stacking direction of the stack, which are susceptible to the effects of low temperatures, is improved, and the high-rate discharge performance of the lead-acid battery itself at low temperatures is also improved.

[0009] Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the following embodiments. In the following embodiments, technically preferable limitations are imposed for carrying out the present invention, but these limitations are not essential requirements for the present invention.

[0010] The lead-acid battery of this embodiment includes a battery case having six cell chambers separated by partition walls, a plate assembly housed in each of the six cell chambers, and an electrolyte injected into each of the six cell chambers. The plate assembly has a stack of alternating positive and negative electrode plates and separators disposed between the positive and negative electrode plates, and the six cell chambers are arranged in the stacking direction of the stack.

[0011] The positive electrode plate is a positive electrode current collector having a lattice substrate and tabs protruding above the lattice substrate, and a positive electrode mixture containing a positive electrode active material is held on the positive electrode current collector.The negative electrode plate is a negative electrode current collector having a lattice substrate and tabs protruding above the lattice substrate, and a negative electrode mixture containing a negative electrode active material is held on the negative electrode current collector.

[0012] The BET specific surface area X of all negative plates constituting the electrode plate group housed in the cell chambers at both ends of the stacking direction (hereinafter referred to as end cells) is 1.00 m ２ / g or less, and the BET specific surface area Y of all negative electrode plates constituting the electrode plate group housed in the cell chambers other than those at both ends in the stacking direction (hereinafter referred to as middle cells) is 0.50 m ２ / g or more 1.00m ２ / g, and the ratio X / Y is greater than 1.00 and not greater than 1.60.

[0013] The distance between adjacent positive and negative electrode plates, i.e., the inter-plate distance, is substantially equal to the thickness of the separator. In this embodiment, the separator is a ribbed separator, and the thickness of the separator (the sum of the separator base thickness and rib height) is 0.6 mm or more and 1.1 mm or less. In other words, the inter-plate distance in the electrode plate assemblies housed in the end cells and the middle cell is 0.6 mm or more and 1.1 mm or less. The thickness of the separator does not change between a state in which the end cell laminate and the middle cell laminate are housed in the cell chamber and subjected to surface pressure, and a state in which they are removed from the cell chamber and exposed to atmospheric pressure.

[0014] The electrolyte is dilute sulfuric acid containing aluminum ions at a concentration of 0.02 mol / L or more and 0.2 mol / L or less.

[0015] [Manufacturing Method] The lead-acid battery of this embodiment can be manufactured, for example, by the following method. First, lead powder containing lead monoxide as a main component, cut polyester fiber, water, and sulfuric acid are mixed together to prepare a positive electrode mixture paste. The obtained positive electrode mixture paste is applied to and filled onto the entire surface of the grid-shaped substrate portion of the positive electrode current collector plate, thereby obtaining a positive electrode filled plate. Then, the mixture is aged and dried to obtain a pre-chemically aged positive electrode plate.

[0016] Next, a negative electrode mixture for the end cell and a negative electrode mixture for the middle cell are prepared by mixing lead powder containing lead monoxide as the main component, cut polyester fiber, carbon black, lignin, barium sulfate, water, and sulfuric acid. To ensure that the specific surface area of ​​the end cell negative electrode plate after chemical conversion is larger than that of the middle cell negative electrode plate, the water content and sulfuric acid content during preparation of the negative electrode mixture paste for the end cell are larger than those of the middle cell negative electrode plate. Then, through the same process as for the positive electrode, a pre-chemically aged end cell negative electrode plate and a pre-chemically aged middle cell negative electrode plate are obtained.

[0017] Next, the pre-chemically aged positive electrode plates were placed in a polyethylene separator bag, and five separators containing the pre-chemically aged positive electrode plates and six pre-chemically aged negative electrode plates were alternately stacked to obtain pre-chemically aged end cell laminates and middle cell laminates. In this process, the end cell laminate used the pre-chemically aged negative electrode plates, and the middle cell laminate used the pre-chemically aged negative electrode plates.

[0018] Next, the laminate is cast using a COS (cast-on-strap) casting machine to form positive straps by connecting the lugs of the positive aged plates together and negative straps by connecting the lugs of the negative aged plates together, and positive intermediate poles, negative intermediate poles, positive poles, and negative poles are formed to obtain electrode plate assemblies. The resulting electrode plate assemblies are then placed in the respective cell compartments of a battery case. At this time, end cell laminates before chemical conversion are placed in the end cells, and middle cell laminates before chemical conversion are placed in the middle cells.

[0019] Next, the positive and negative intermediate poles, which face each other across the partition wall separating the cell chambers of the battery case, are resistance-welded at the through-holes in the partition wall, electrically connecting adjacent cells in series. Next, the top surface of the battery case and the bottom surface of the lid are thermally melted, and the lid is placed on the battery case and secured to the battery case by thermal welding. When placing the lid on the battery case, the positive and negative poles are passed through the through-holes in the bushings insert-molded into the lid. The positive and negative poles, which protrude from the through-holes in the bushings, are then heated with a burner or similar device to integrate them with the bushings, forming the positive and negative terminals. This completes the assembly of the lead-acid battery. Next, electrolyte (sulfuric acid with aluminum sulfate added) is injected into each cell chamber through the filling holes in the lid, followed by sealing the filling holes, as is typical. The battery is then chemically formed to obtain a lead-acid battery.

[0020] [Actions and Effects] In the lead-acid battery of this embodiment, the BET specific surface area X of all negative electrode plates constituting the electrode plate group housed in the end cell is 1.00 m ２ / g or less, and the BET specific surface area Y of all negative electrode plates constituting the electrode plate group housed in the middle cell is 0.50 m ２ / g or more 1.00m ２ / g, the ratio X / Y is greater than 1.00 and equal to or less than 1.60, the distance between the electrodes is 0.6 mm or more and 1.1 mm or less, and the aluminum ion concentration of the electrolyte is 0.02 mol / L or more and 0.2 mol / L or less.

[0021] First, the BET specific surface area X of all negative electrodes constituting the electrode plate group housed in the end cell is 1.00 m ２ / g or less, and the BET specific surface area Y of all negative electrode plates constituting the electrode plate group housed in the middle cell is 0.50 m ２ / g or more 1.00m ２ / g and the ratio X / Y is greater than 1.00 and not greater than 1.60, the reaction area in the negative electrode plate of the end cell that is susceptible to low temperatures is large, resulting in superior CCA and low-temperature discharge duration compared to when this value and ratio are outside this range.

[0022] Furthermore, by setting the inter-electrode distance to 0.6 mm or more and 1.1 mm or less, the internal resistance of the battery is reduced compared to when the value is outside this range, and discharge performance can be further improved.

[0023] Furthermore, by setting the aluminum ion concentration in the electrolyte to 0.02 mol / L or more and 0.2 mol / L or less, the lead sulfate produced during discharge becomes finer than when the concentration is outside this range, which makes it easier for the reduction reaction of lead sulfate to proceed during charge, thereby particularly improving charge acceptance.

[0024] [Fabrication of Test Batteries] Lead-acid batteries of Examples 1 to 9 and Comparative Examples 1 to 6 were fabricated using the conventionally known methods described in the embodiments, as lead-acid batteries having the same structure as the lead-acid battery of the present embodiment. Specifically, the test batteries were JIS K42 size lead-acid batteries with an operating voltage of 12 V and a 20-hour rate capacity of 30 Ah.

[0025] Example 1 First, a positive electrode mixture paste was prepared by kneading lead powder containing lead monoxide as the main component, cut polyester fiber, water, and sulfuric acid. The resulting positive electrode mixture paste was applied to and filled onto the entire surface of a grid-shaped substrate portion of a current collector plate made of a Pb—Ca—Sn alloy, thereby obtaining a positive electrode filled plate. Subsequently, the positive electrode filled plate was aged and dried in a conventional manner, yielding a pre-chemically aged positive electrode plate.

[0026] Next, lead powder containing lead monoxide as the main component, cut polyester fiber, carbon black, lignin, barium sulfate, water, and sulfuric acid were mixed to prepare a negative electrode mixture for the end cell and a negative electrode mixture for the middle cell. In this case, the negative electrode mixture for the end cell was prepared so that the BET specific surface area of ​​the negative electrode plate after chemical formation was 1.00 m. ２ For the negative electrode mixture for the medium cell, the BET specific surface area of ​​the negative electrode plate after formation was set to 0.97 m / g. ２ The amounts of water and sulfuric acid mixed into the paste were adjusted so that the sintering ratio was 1 / g. This paste was filled into a current collector made of a Pb-Ca-Sn alloy, and then aged and dried in a conventional manner to prepare anode aged plates for end cells and anode aged plates for a middle cell before chemical conversion.

[0027] Next, the pre-chemically treated positive electrode aged plates were placed in a polyethylene pouch-shaped separator, and five separators containing the pre-chemically treated positive electrode aged plates and six pre-chemically treated negative electrode aged plates for the end cell were alternately stacked to form two pre-chemically treated end cell stacks. The resulting end cell stacks were then cast using a COS-type casting machine to form positive electrode straps by connecting the edge portions of the positive electrode aged plates together and negative electrode straps by connecting the edge portions of the negative electrode aged plates together, as well as forming positive electrode intermediate poles, negative electrode intermediate poles, positive electrode poles, and negative electrode poles, thereby obtaining two end cell electrode plate assemblies.

[0028] In this case, a pouch-shaped separator was used in the end cell electrode plate assembly and the middle cell electrode plate assembly so that the distance between the electrodes was 0.7 mm.

[0029] Next, five separators containing pre-chemically aged positive electrode plates and six pre-chemically aged negative electrode plates for the middle cell were alternately stacked to form four pre-chemically aged middle cell stacks. The four resulting middle cell stacks were subjected to the same process as for preparing the end cell electrode assembly to obtain four middle cell electrode assembly. Next, the end cell electrode assembly was placed in the end cell of a JIS K42-sized monoblock polypropylene battery case, and the middle cell electrode assembly was placed in the middle cell.

[0030] Next, the positive and negative intermediate poles, which faced each other across the partition wall separating the cell chambers of the battery case, were connected by resistance welding at the through holes provided in the partition wall. In this state, a pre-chemical electrode group was placed in each cell chamber of the battery case. The battery case and lid in this state were thermally welded together using the method described in this embodiment, thereby obtaining a pre-chemical lead-acid battery of Example 1.

[0031] Next, 340 mL of an electrolyte solution consisting of dilute sulfuric acid with a specific gravity of 1.23 and aluminum sulfate dissolved therein to give an aluminum concentration of 0.18 mol / L was added to each cell before chemical formation. Next, the battery was subjected to chemical formation with a charge amount of 214% of the theoretical capacity of the positive electrode, and the BET specific surface area of ​​the negative electrode plate of the end cell was adjusted to 1.00 m. ２ / g, and the BET specific surface area of ​​the negative electrode plate of the middle cell is 0.97 m ２ The lead acid battery of Example 1 having a capacitance of 1 / g was obtained.

[0032] (Example 2) The BET specific surface area of ​​the negative electrode plate of the end cell was 1.00 m２ / g, and the BET specific surface area of ​​the negative electrode plate of the middle cell is 0.80 m ２ The lead acid battery of Example 2 was obtained in the same manner as in Example 1, except that the amounts of water and sulfuric acid in preparing the paste were adjusted so that the ZnO content was 1 / g.

[0033] (Example 3) The BET specific surface area of ​​the negative electrode plate of the end cell was 1.00 m ２ / g, and the BET specific surface area of ​​the negative electrode plate of the middle cell is 0.70 m ２ The lead acid battery of Example 3 was obtained in the same manner as in Example 1, except that the amounts of water and sulfuric acid in preparing the paste were adjusted so that the ZnO content was 1 / g.

[0034] (Example 4) The BET specific surface area of ​​the negative electrode plate of the end cell was 0.90 m ２ / g, and the BET specific surface area of ​​the negative electrode plate of the middle cell is 0.60 m ２ The lead acid battery of Example 4 was obtained in the same manner as in Example 1, except that the amounts of water and sulfuric acid in preparing the paste were adjusted so that the ZnO content was 1 / g.

[0035] (Example 5) The BET specific surface area of ​​the negative electrode plate of the end cell was 0.84 m ２ / g, and the BET specific surface area of ​​the negative electrode plate of the middle cell is 0.80 m ２ The lead acid battery of Example 5 was obtained in the same manner as in Example 1, except that the amounts of water and sulfuric acid in preparing the paste were adjusted so that the ZnO content was 1 / g.

[0036] (Example 6) The BET specific surface area of ​​the negative electrode plate of the end cell was 0.80 m ２ / g, and the BET specific surface area of ​​the negative electrode plate of the middle cell is 0.60 m ２ The lead acid battery of Example 6 was obtained in the same manner as in Example 1, except that the amounts of water and sulfuric acid in preparing the paste were adjusted so that the ZnO content was 1 / g.

[0037] (Example 7) The BET specific surface area of ​​the negative electrode plate of the end cell was 0.80 m ２ / g, and the BET specific surface area of ​​the negative electrode plate of the middle cell is 0.50 m ２ The lead acid battery of Example 7 was obtained in the same manner as in Example 1, except that the amounts of water and sulfuric acid in preparing the paste were adjusted so that the ZnO content was 1 / g.

[0038] (Example 8) The BET specific surface area of ​​the negative electrode plate of the end cell was 0.63 m ２ / g, and the BET specific surface area of ​​the negative electrode plate of the middle cell is 0.50 m ２ The lead acid battery of Example 8 was obtained in the same manner as in Example 1, except that the amounts of water and sulfuric acid in preparing the paste were adjusted so that the ZnO content was 1 / g.

[0039] (Example 9) The BET specific surface area of ​​the negative electrode plate of the end cell was 0.52 m ２ / g, and the BET specific surface area of ​​the negative electrode plate of the middle cell is 0.50 m ２ A lead acid battery of Example 9 was obtained in the same manner as in Example 1, except that the amounts of water and sulfuric acid in preparing the paste were adjusted so that the ZnO content was 1 / g.

[0040] (Comparative Example 1) The BET specific surface area of ​​the negative electrode plate of the end cell was 1.10 m ２ / g, and the BET specific surface area of ​​the negative electrode plate of the middle cell is 0.80 m ２ A lead acid battery of Comparative Example 1 was obtained in the same manner as in Example 1, except that the amounts of water and sulfuric acid in preparing the paste were adjusted so that the ZnO content was 1 / g.

[0041] (Comparative Example 2) The BET specific surface area of ​​the negative electrode plate of the end cell and the negative electrode plate of the middle cell was 1.00 m ２ A lead acid battery of Comparative Example 2 was obtained in the same manner as in Example 1, except that the amounts of water and sulfuric acid in preparing the paste were adjusted so that the ZnO content was 1 / g.

[0042] (Comparative Example 3) The BET specific surface area of ​​the negative electrode plate of the end cell was 1.00 m ２ / g, and the BET specific surface area of ​​the negative electrode plate of the middle cell is 0.60 m ２ A lead acid battery of Comparative Example 3 was obtained in the same manner as in Example 1, except that the amounts of water and sulfuric acid in preparing the paste were adjusted so that the ZnO content was 1 / g.

[0043] (Comparative Example 4) The BET specific surface area of ​​the negative electrode plate of the end cell and the negative electrode plate of the middle cell was 0.70 m ２ A lead acid battery of Comparative Example 4 was obtained in the same manner as in Example 1, except that the amounts of water and sulfuric acid in preparing the paste were adjusted so that the ZnO content was 1 / g.

[0044] (Comparative Example 5) The BET specific surface area of ​​the negative electrode plate of the end cell was 0.70 m ２ / g, and the BET specific surface area of ​​the negative electrode plate of the middle cell is 0.80 m ２ A lead acid battery of Comparative Example 5 was obtained in the same manner as in Example 1, except that the amounts of water and sulfuric acid in preparing the paste were adjusted so that the ZnO content was 1 / g.

[0045] (Comparative Example 6) The BET specific surface area of ​​the negative electrode plate of the end cell was 0.50 m ２ / g, and the BET specific surface area of ​​the negative electrode plate of the middle cell is 0.40 m ２ A lead acid battery of Comparative Example 6 was obtained in the same manner as in Example 1, except that the amounts of water and sulfuric acid in preparing the paste were adjusted so that the ZnO content was 1 / g.

[0046] [Evaluation of Physical Properties of Negative Electrode Mixture] In Examples 1 to 9 and Comparative Examples 1 to 6, the prepared lead-acid batteries were disassembled, and the physical properties of the negative electrode mix after chemical formation (fully charged) were evaluated. Specifically, the electrode plate group was removed from the cell chamber and disassembled, and the negative electrode plate was removed. Thereafter, the negative electrode plate was washed with water and dried, and the negative electrode mix was separated from the lattice-shaped substrate portion. The BET specific surface area was measured using a high-performance specific surface area / pore distribution measurement device (Shimadzu Corporation, micromeritics ASAP2020).

[0047] [Battery Testing and Evaluation] The obtained lead-acid batteries of Examples 1 to 9 and Comparative Examples 1 to 6 were subjected to the rated cold cranking current (CCA) as specified in JIS D5306:2021 1.00.3 and the high-rate discharge characteristic test (-15°C) as specified in JIS D5301:2019 C.4, and low-temperature discharge duration was measured. Specifically, the batteries were fully charged and then placed in a thermostatic chamber at -18°C for 24 hours. Thereafter, the batteries were discharged at a discharge current of 330 A for 30 seconds, and the terminal voltage at 30 seconds was recorded. The CCA was calculated by substituting the current value and the voltage at 30 seconds into the following formula: CCA = (11.5 - 7.2) / (11.5 - V １ ) × A １ V １ : 30 seconds after discharge, A １ : discharge test current

[0048] Next, the fully charged batteries were placed in a thermostatic chamber at -15°C for 16 hours. Thereafter, they were discharged at a discharge current of 150A until the terminal voltage reached 6V, and the discharge duration [minutes] until the terminal voltage dropped to 6V was measured. These test results, namely the BET specific surface areas X and Y of the end and middle cells, the ratio X / Y of the end cell specific surface area to the middle cell specific surface area, CCA, and low-temperature discharge duration of the lead-acid batteries of Examples 1 to 9 and Comparative Examples 1 to 6, are shown in Table 1.

[0049] The CCA values ​​for the lead-acid batteries of Examples 1 to 9 and Comparative Examples 1 to 6 are relative values ​​when the CCA of Comparative Example 4, a conventional example, is taken as 100%. The low-temperature discharge duration is a relative value when the discharge duration (3.0 minutes) specified in 40B19 of JIS D5301:2019 Table B.1 Type List is taken as 100%. Regarding the evaluation based on the test results, if the CCA (relative value) was greater than 100% and the low-temperature discharge duration (relative value) was greater than 100%, it was marked as "Good." If the CCA (relative value) was 100% or less, or the low-temperature discharge duration (relative value) was 100% or less, it was marked as "Poor."

[0050]

[0051] As shown in Table 1, the BET specific surface area X of the negative electrode plate of the end cell is 1.00 m ２ / g or less, and the BET specific surface area Y of the negative electrode plate of the middle cell is 0.50 m ２ / g or more 1.00m ２ / g and the ratio X / Y of the end cell is greater than 1.00 and not greater than 1.60, the lead-acid battery has a large reaction area in the negative electrode plate of the end cell that is susceptible to the effects of low temperatures, and therefore has excellent CCA and low-temperature discharge duration compared to the conventional example (Comparative Example 4).

[0052] On the other hand, the BET specific surface area X of the negative electrode plate of the end cell is 1.00 m ２ / g, the CCA is insufficient, and the BET specific surface area Y of the negative electrode plate of the middle cell is 0.50 m ２ A lead-acid battery having a capacitance of less than 1 / g tends to have an insufficient duration of low-temperature high-rate discharge.

[0053] Furthermore, if X / Y is less than 1.00, the low-temperature effect on the end cells with a small specific surface area of ​​the negative electrode plate is large, resulting in insufficient high-rate discharge performance at low temperatures.If X / Y is more than 1.60, the difference in the specific surface area of ​​the negative electrode plate between the end cells and the middle cell becomes too large, resulting in insufficient high-rate discharge performance at low temperatures.

Claims

1. A battery comprising: a battery case having a plurality of cell chambers separated by partition walls; a plate assembly housed in each of the plurality of cell chambers; and an electrolyte injected into each of the plurality of cell chambers, wherein the plate assembly has a stack consisting of a plurality of alternatingly arranged positive and negative electrode plates and separators disposed between the positive and negative electrode plates, the plurality of cell chambers are arranged along the stacking direction of the stack, and the BET specific surface area X of the negative electrode plate constituting the plate assembly housed in the cell chambers at both ends of the stacking direction of the stack is 1.00 m ２ / g or less, and the BET specific surface area Y of the negative electrode plate constituting the electrode plate group housed in the cell chamber other than both ends of the stacking direction of the stack is 0.50 m ２ / g or more 1.00m ２ / g or less, and the ratio X / Y is greater than 1.00 and not greater than 1.

60.

2. A lead-acid battery according to claim 1, wherein the distance between adjacent positive and negative electrode plates is 0.6 mm or more and 1.1 mm or less.

3. A lead-acid battery according to claim 1 or 2, wherein the electrolyte is dilute sulfuric acid containing aluminum ions at a concentration of 0.02 mol / L or more and 0.2 mol / L or less.

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