JP6582386B2 - Lead acid battery - Google Patents

Description

  The present invention relates to a lead-acid battery.

  Lead storage batteries are widely used for industrial use and consumer use because of their reliability and low price. In particular, there is a great demand for lead storage batteries for automobiles (so-called batteries).

  In recent years, as an effort to protect the environment and improve fuel efficiency, the development of an idling stop start (hereinafter abbreviated as ISS) vehicle that stops the engine when the vehicle stops and restarts the vehicle when starting is accelerated. Lead storage batteries installed in ISS cars frequently start and stop the engine, increasing the number of large current discharges at start-up, requiring electric power to be supplied to electrical components while the vehicle is stopped, and increasing the discharge load. The vehicle is charged by an alternator, which stops when the vehicle is stopped because the engine is used as a power source. Under these usage conditions peculiar to the ISS, the lead-acid battery is used in a state where it is not completely charged, that is, in a partially charged state (PSOC).

  When a lead-acid battery is used in the PSOC state, a problem that does not occur in a situation where the battery is used in a conventional full charge state occurs. This is known as a so-called ear-thinning phenomenon in which the current collector (ear part) of the negative electrode grid is discharged and the thickness of the current collector decreases. When the earburn phenomenon occurs, the resistance of the current collector increases, the charge / discharge characteristics of the lead-acid battery deteriorate, and the cycle life performance deteriorates.

  In Patent Document 1, a lead-tin alloy layer is provided on the surface of the ear portion of the negative electrode lattice body, and the negative electrode active material after full charge is contained in an amount of 0.25 to 0.75% by mass of carbon. A technique for suppressing skinnyness is disclosed.

Republished WO2010 / 032782

  The negative electrode plate is produced by filling an active material paste into a negative electrode grid. The active material paste is prepared by mixing an organic additive, carbon, and barium sulfate with lead powder, adding water and dilute sulfuric acid, and kneading. Carbon or a carbon material is added as a conductive auxiliary agent.

  Usually, in a lead storage battery, 0.1 to 0.3 mass% of carbon is contained with respect to the negative electrode active material after full charge. When the amount of carbon is increased by 0.5% by mass or more, the active material paste becomes hard, it becomes difficult to fill the negative electrode lattice body, filling failure occurs, and the yield decreases.

  In order to make the active material paste have an appropriate hardness, there is a method of increasing the amount of water by increasing the amount of water added during the kneading. However, in the negative electrode plate with an increased amount of paste water, the active material shrinks due to the release of water in the aging and drying steps after filling, and cracks occur on the surface of the negative electrode plate. In such a state, the active material falls off in the subsequent battery assembly process. Therefore, it is not preferable to increase the paste water content.

  An object of the present invention is to alleviate the ear burn of the negative electrode current collector without changing the paste specifications.

  Therefore, the present invention has the following configuration in order to solve the above problems.

1st invention WHEREIN: In the lead storage battery which accommodates the electrode group which laminated | stacked the positive electrode plate and the negative electrode plate alternately via the separator in a battery case, the total surface area of the said positive electrode plate is set to S, and the volume of the said electrode plate group is set to V. When S / V is 3.95 cm ⁻¹ or more, the active material amount of the positive electrode plate is X, and the active material amount of the negative electrode plate is Y, X / Y is 1.35 or more. And

According to a second invention, in the first invention, S / V is 4.2 cm ⁻¹ or more and X / Y is 1.45 or more.

  According to the present invention, it is possible to relieve the earring of the negative electrode current collector without changing the paste specifications, and it is possible to obtain a lead storage battery having excellent cycle life characteristics.

It is a figure which shows the electrode group of this invention. It is a figure which shows an expanded lattice body. It is a figure which shows a positive electrode plate. It is a figure which shows a microporous polyethylene sheet. It is a figure which puts a negative electrode plate in a bag separator. It is a figure which shows a battery case. It is a figure which shows a battery.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

(Lattice)
As the lattice body, the expanded lattice body 1 shown in FIG. 2 expanded by cutting a lead-calcium-tin alloy sheet was used. The dimensions excluding the current collector 2 are 145 mm wide, 115 mm high, and 1.5 mm thick for the positive electrode, and 145 mm wide, 115 mm high, and 1.3 mm thick for the negative electrode. The current collector 2 is also called an ear.

(Positive electrode plate)
An active material paste is prepared by adding slurry and water and dilute sulfuric acid prepared by mixing and reacting lead tan with a lead oxidation degree of 90% to dilute sulfuric acid to lead powder with an oxidation degree of 70% produced by the ball mill method. . The active material paste is filled into the positive electrode expanded lattice 1 and after aging and drying by a conventional method, the positive electrode plate 3 shown in FIG. 3 is obtained. In FIG. 2, the portion filled with the active material paste is a filling portion 4.

(Negative electrode plate)
Carbon powder, lignin powder, and barium compound powder are added and mixed as additives to lead powder having a degree of oxidation of 70% produced by the ball mill method. Subsequently, water and dilute sulfuric acid are added and kneaded to prepare an active material paste. The active material paste is filled into the negative electrode expanded lattice and aged and dried by a conventional method to form a negative electrode plate.

(Bag separator)
FIG. 4 shows a microporous polyethylene sheet 6. A separator rib 7 is provided on one side of the polyethylene sheet 6 in the longitudinal direction. The thickness of the base portion of the polyethylene sheet 6 is 0.2 mm, and the total thickness including the rib 7 is 0.8 mm. The polyethylene sheet 6 is cut into a length of 235 mm and a width of 152 mm and folded in half. Subsequently, both sides are mechanically sealed or heat-welded and processed into a bag separator 8 as shown in FIG.

(Strap formation and electrode plate group)
As shown in FIG. 5, the negative electrode plate 5 is put in the bag separator 8, and the seven positive electrode plates and the eight negative electrode plates wrapped in the bag separator are alternately laminated. The current collector 2 of each of the positive electrode and the negative electrode is welded by a cast on strap method to form a welded portion, that is, a strap 9 shown in FIG.
As the alloy composition of the strap 9, a lead-antimony alloy or a lead-tin alloy can be used.

(Battery case)
FIG. 6 shows a battery case 11 made of polypropylene. The battery case 11 is divided into six sections by a partition wall 12 and a cell chamber 13 is provided. The electrode plate group 10 is also called a single cell, which has only a battery capacity of 2V. In order to drive an electric component for automobiles by stepping up or down a DC voltage of 12V, six electrode plate groups 10 are connected in series to be 2V × 6 = 12V. Therefore, six cell chambers 13 are required.
A plurality of ribs 14 are provided in the height direction of the battery case 11 on both surfaces of the partition wall 12 of the battery case 11 and inner wall surfaces of both end surfaces of the battery case 11. The rib 14 has a role of appropriately pressing the electrode plate group.

(Production of battery)
The electrode plate group 10 is inserted into the cell chamber 13 of the battery case 11, and the straps 9 between adjacent electrode plate groups are welded by partition wall welding. A polypropylene lid 15 is heat-welded to the battery case 11 to produce a battery 16 shown in FIG. In the electrode plate group 10 accommodated in the cell chambers at both ends shown in FIG. This is for connection to the positive terminal 17A and the negative terminal 17B protruding from the lid 15.

  Subsequently, dilute sulfuric acid, which is an electrolytic solution, is injected from the injection port 18 corresponding to the cell chamber 13 of the lid 15 and energized for 20 hours at an ambient temperature of 40 ° C. and a current of 25 A to form a battery case. After the formation of the battery case, the electrolyte solution level was adjusted to produce an 80D23 type battery defined by JIS D5301.

(Total surface area of positive electrode plate, volume of electrode plate group)
The total surface area of the positive electrode plate 3 is the surface area of the portion of the positive electrode plate 3 involved in power generation in the unit cell that is the smallest unit of the lead storage battery, that is, the electrode plate group 10 accommodated in the cell chamber 13. It is the sum. In FIG. 3, the total number of the surface areas of the front and back surfaces of the positive electrode plates excluding the current collecting part 2 and the unfilled part of the active material paste is the number of positive electrode plates constituting the electrode group 10. It is multiplied.
That is, the total surface area S of the positive electrode plate per electrode plate group 10 is given by (Equation 1) from FIG. In the present invention, [cm ² ] is used as the unit of S.
S = (filling part width × filling part height) × 2 × number of positive electrode plates (Equation 1)
The volume of the electrode plate group 10 is a portion of the electrode plate group accommodated in one cell, which is the minimum unit of the lead storage battery, and does not include the current collector 2 and the strap 9. This is the apparent volume calculated from the external dimensions including the protruding portion not in contact with the rib and the height of the ribs 7 on both end faces of the electrode plate group 10.

That is, the volume V of the electrode plate group 10 is given by (Equation 2) from FIG. In the present invention, [cm ³ ] is used as a unit of V.
V = electrode group width × electrode group thickness × electrode group height (Equation 2)
(Amount of active material)
The amount of active material is the total amount of active material after the formation of the battery case, and is a value obtained by subtracting the total mass of the grid from the total mass of the electrode plate.

  That is, the positive electrode active material amount is obtained by multiplying the active material amount of one positive electrode plate 3 by the number of positive electrode plates constituting the electrode plate group 10. The amount of negative electrode active material is obtained by multiplying the amount of active material of one negative electrode plate 4 by the number of negative electrode plates constituting the electrode plate group 10.

(Evaluation test)
The following tests are performed on the battery in a 25 ° C. environment.
(A) Constant current discharge at a current of 59 A for 59 seconds.
(A) Constant current discharge at a current of 300 A for 1 second.
(C) Constant current / constant voltage charging at a constant voltage of 14.0 V and a limiting current of 100 A for 1 minute.
(D) Charging / discharging is repeated with (a) to (c) as one cycle.
The battery life is determined when the first-second current in (b) becomes 7.2 V or less.

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

(Example 1)
In the 80D23 type battery, S / V was produced as follows.
From (Equation 1), S = (14.5 × 11) × 2 × 7 = 2233 [cm ² ]
From (Expression 2), V = 14.5 × 3.36 × 11.6 = 565 [cm ³ ]
Therefore, S / V is 3.95 cm ⁻¹ .
X / Y was made to be 1.35.

(Example 2)
In Example 1, a battery having S / V of 3.95 cm ⁻¹ and X / Y of 1.4 was produced.

Example 3
In Example 1, a battery having S / V of 3.95 cm ⁻¹ and X / Y of 1.45 was produced.

Example 4
In Example 1, a battery having S / V of 3.95 cm ⁻¹ and X / Y of 1.47 was manufactured.

(Example 5)
In Example 1, a battery having S / V of 4.1 cm ⁻¹ and X / Y of 1.35 was produced.

(Example 6)
In Example 1, a battery having S / V of 4.1 cm ⁻¹ and X / Y of 1.4 was produced.

(Example 7)
In Example 1, a battery having S / V of 4.1 cm ⁻¹ and X / Y of 1.45 was produced.

(Example 8)
In Example 1, a battery having S / V of 4.1 cm ⁻¹ and X / Y of 1.47 was manufactured.

Example 9
In Example 1, a battery having S / V of 4.2 cm ⁻¹ and X / Y of 1.35 was produced.

(Example 10)
In Example 1, a battery having S / V of 4.2 cm ⁻¹ and X / Y of 1.4 was produced.

(Example 11)
In Example 1, a battery having S / V of 4.2 cm ⁻¹ and X / Y of 1.45 was produced.

Example 12
In Example 1, a battery having S / V of 4.2 cm ⁻¹ and X / Y of 1.47 was manufactured.

(Example 13)
In Example 1, a battery having S / V of 4.3 cm ⁻¹ and X / Y of 1.35 was produced.

(Example 14)
In Example 1, a battery having S / V of 4.3 cm ⁻¹ and X / Y of 1.4 was produced.

(Example 15)
In Example 1, a battery having S / V of 4.3 cm ⁻¹ and X / Y of 1.45 was produced.

(Example 16)
In Example 1, a battery having S / V of 4.3 cm ⁻¹ and X / Y of 1.47 was manufactured.

(Comparative Example 1)
In Example 1, a battery having S / V of 3.95 cm ⁻¹ and X / Y of 1.33 was produced.

(Comparative Example 2)
In Example 1, a battery having S / V of 4.1 cm ⁻¹ and X / Y of 1.33 was produced.

(Comparative Example 3)
In Example 1, a battery having S / V of 4.2 cm ⁻¹ and X / Y of 1.33 was produced.

(Comparative Example 4)
In Example 1, a battery having S / V of 4.3 cm ⁻¹ and X / Y of 1.33 was produced.

(Comparative Example 5)
In Example 1, a battery having S / V of 3.9 cm ⁻¹ and X / Y of 1.35 was produced.

(Comparative Example 6)
In Example 1, a battery having S / V of 3.9 cm ⁻¹ and X / Y of 1.4 was produced.

(Comparative Example 7)
In Example 1, a battery having S / V of 3.9 cm ⁻¹ and X / Y of 1.45 was produced.

(Comparative Example 8)
In Example 1, a battery having S / V of 3.9 cm ⁻¹ and X / Y of 1.47 was manufactured.

(Comparative Example 9)
In Example 1, a battery having S / V of 3.9 cm ⁻¹ and X / Y of 1.33 was produced.

  Table 1 shows the results of the number of cycles when performing a life test of these lead storage batteries.

It turns out that Examples 1-16 using this invention are excellent in the number of life cycles. In order to verify the life mode, when each battery was disassembled with the life cycle number of Comparative Example 9, the thickness of the current collecting part (ear part) was the smallest in Comparative Example 9, and Examples 11, 12, 15, and 16 were the most. It was thick. Than this,
In the present example, it can be said that the burn-up of the negative electrode current collector can be alleviated and the cycle life characteristics have been improved.

Although it is not clear, the ratio of the total surface area of the positive electrode plate to the electrode group volume (S / V) is not less than 3.95 cm ⁻¹ , and it is considered that the increase in overvoltage during charging is moderated. . Moreover, it is considered that the ratio of the positive electrode active material to the negative electrode active material (X / Y) is 1.35 or more, so that lead sulfate generated at the negative electrode ear is completely reduced to metallic lead. In particular, it is considered that when the surface area of the positive electrode plate is increased, the resistance is decreased and the overvoltage is further lowered. Therefore, the S / V is preferably 4.2 cm ⁻¹ or more. Further, since it is considered that the negative electrode is reduced at a sufficiently low potential by increasing the amount of the active material of the positive electrode, X / Y is preferably 1.45 or more.

In addition, although the upper limit is not prescribed | regulated in this invention, the upper limit of S / V is 5.2 cm < ^-1 > and the upper limit of X / Y is 1.6 for practical use of a lead storage battery.

In the present invention, although the upper limit value of S / V is not specified, the upper limit is preferably 5.2 cm ⁻¹ for practical use of the lead storage battery.

  In the above embodiment, the S / V was changed by adjusting the thickness of the electrode plate. However, the S / V was also changed by changing the thickness of the expanded lattice 1, the base thickness of the polyethylene sheet 6, and the height of the rib 7. It can also be changed.

1. Expanded lattice, 2. 2. current collector; Positive electrode plate, 4. Filling section, 5. Negative electrode plate, 6. 6. a polyethylene sheet; Ribs, 8. Bag separator, 9. Strap, 10. 10. Electrode plate group, Battery case, 12. Partition, 13. Cell chamber, 14. Ribs, 15. Lid, 16. Battery, 17A. Positive terminal, 17B. Negative electrode terminal, 18. Injection port

Claims (2)

In a lead storage battery in which a battery case in which a group of electrode plates in which a positive electrode plate and a negative electrode plate are alternately stacked via a separator is housed in a battery case, when the total surface area of the positive electrode plate is S and the volume of the electrode plate group is V, S / V is less 3.95Cm ^-1 or 5.2 cm ^-1, and an active material of the positive electrode plate X, when the amount of active material of the negative electrode plate was Y, X / Y is 1.35 or more Lead acid battery characterized by being 1.47 or less . According to claim 1, lead-acid batteries S / V is at 4.2 cm ^-1 or more, and, X / Y is equal to or is on 1.45 or more.