JP2015008151A - Lead-acid battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress accumulation of lead sulphate due to the repetition of idling stop while increasing capacity, such as a 5 hour rate capacity, of a lead-acid battery.SOLUTION: A lead-acid battery includes a positive electrode plate, a negative electrode plate, and an electrolyte containing sulfuric acid and aluminum ions. The mass ratio between a negative electrode active material of the negative electrode plate and a positive electrode active material of the positive electrode plate is 0.6 or more and 0.85 or less, and the aluminum ion concentration in the electrolyte is 0.02 mol/L or more and 0.2 mol/L or less. Accordingly, a lead-acid battery high in capacity and excellent in idling stop life can be obtained.

Description

  The present invention relates to a lead storage battery.

  In an idling stop vehicle, a charge control vehicle, etc., the opportunity to charge the storage battery is limited. On the other hand, as seen in restarting the engine after the idling stop, the electric power taken out from the storage battery is increasing. For this reason, a high capacity lead acid battery is required. The inventor examined increasing the capacity of the storage battery, such as the 5-hour rate capacity, by increasing the amount of the positive electrode active material of the lead storage battery than the amount of the negative electrode active material. However, when the mass ratio of the negative electrode active material amount to the positive electrode active material amount is 0.85 or less, the low-temperature high-rate discharge performance is lowered, and a large amount of lead sulfate accumulates on the negative electrode due to repeated idling stops. Therefore, it is necessary to maintain the low temperature and high rate discharge performance while increasing the capacity of the lead storage battery and to suppress the accumulation of lead sulfate due to repeated idling stops.

Here is related prior art. Patent Document 1 (WO2007 / 036979)
・ When aluminum ions are included in the electrolyte of lead-acid batteries, accumulation of lead sulfate on the negative electrode is suppressed,
・ It is said that when lithium ion is included in the electrolyte of a lead storage battery, the 5-hour rate capacity increases.
However, in the experiments by the inventors, inclusion of lithium ions in the electrolytic solution did not increase the 5-hour rate capacity of the storage battery.

WO2007 / 036979

  An object of the present invention is to suppress the accumulation of lead sulfate due to repeated idling stops while increasing the capacity of the lead-acid battery such as the 5-hour rate capacity.

  The present invention provides a lead storage battery including a positive electrode plate, a negative electrode plate, and an electrolyte solution containing sulfuric acid and aluminum ions, wherein a mass ratio of the negative electrode active material of the negative electrode plate to the positive electrode active material of the positive electrode plate is 0.6 or more and 0.85 or less And the aluminum ion concentration in the electrolyte is 0.02 mol / L or more and 0.2 mol / L or less.

  According to the inventor's experiment, the mass ratio between the negative electrode active material and the positive electrode active material is 0.6 or more and 0.85 or less, and the aluminum ion concentration in the electrolytic solution is 0.02 mol / L or more and 0.2 mol / L or less. A lead-acid battery having a large capacity such as a time rate capacity and a small amount of lead sulfate accumulated in the negative electrode can be obtained. When the influence of each element is examined individually, the capacity of the storage battery is increased by setting the mass ratio of the negative electrode active material and the positive electrode active material to 0.85 or less. On the other hand, when the mass ratio of the negative electrode active material to the positive electrode active material is less than 0.6, the low-temperature high-rate discharge performance is degraded. Therefore, the mass ratio of the negative electrode active material to the positive electrode active material is set to 0.6 or more.

  When the aluminum ion concentration is less than 0.02 mol / L, the accumulation of lead sulfate on the negative electrode can be suppressed only slightly, while at 0.02 mol / L or more, the accumulation of lead sulfate can be sufficiently suppressed. Moreover, when the aluminum ion concentration exceeds 0.2 mol / L, the low-temperature high-rate discharge performance deteriorates. Therefore, the aluminum ion concentration is set to 0.02 mol / L or more and 0.2 mol / L or less.

  The lithium ion concentration in the electrolyte is, for example, 0.01 mol / L or less.

  When the mass ratio of the negative electrode active material to the positive electrode active material is 0.7 or more and 0.8 or less, as shown in Table 1, the capacity of the lead storage battery such as the 5-hour rate capacity can be particularly increased.

  Examples of the present invention will be shown below. In carrying out the present invention, the embodiments can be appropriately changed in accordance with common sense of those skilled in the art and disclosure of prior art.

  Using a Pb—Ca—Sn alloy, a positive electrode lattice and a negative electrode lattice were produced by a rotary expanding method. The composition of the lattice is arbitrary, and instead of the rotary expanding method, a reciprocating expanding method, a gravity casting method or the like may be used.

Synthetic resin fiber was added to lead powder produced by a ball mill method as a positive electrode active material according to a conventional method, pasted with water and dilute sulfuric acid, filled into a positive electrode lattice, aged and dried to obtain an unformed positive electrode plate. Similarly, synthetic resin fiber, BaSO ₄ , lignin and carbon black are added to the lead powder produced by the ball mill method as the negative electrode active material according to a conventional method, and the mixture is pasted with water and dilute sulfuric acid, filled into the negative electrode lattice, aged and dried. To obtain an unformed negative electrode plate. When filling the paste, the paste mass was changed and filled so that the mass ratio of the active material on the negative electrode side to the positive electrode side was 7 steps of 1,0.9,0.85,0.8,0.75,0.6,0.55. . An active material mass ratio of 1 and 0.9 corresponds to the conventional example, and 0.85 to 0.55 is a range in which the mass ratio is smaller than that of the conventional example. Further, when changing the mass ratio of the active material, the total mass of the negative electrode active material and the positive electrode active material was kept constant so that the mass of the storage battery did not change. The mass of the active material means the mass of the active material separated from the negative electrode plate and the positive electrode plate after the storage battery is disassembled in the state after chemical conversion, the negative electrode plate and the positive electrode plate are washed with water to remove sulfuric acid, and then dried. . The mass ratio of the negative electrode active material to the positive electrode active material is not the mass ratio of the active material per electrode plate, but the total mass of the negative electrode active material in a plurality of negative electrode plates in the same cell and the plurality of positive electrodes It is a ratio with the mass of the total positive electrode active material in a board. The manufacturing method and manufacturing conditions of lead powder are arbitrary, and the additive to lead powder is also arbitrary.

  The unformed negative plate was wrapped with a polyethylene porous separator, and the unformed negative plate and the unformed positive plate were alternately stacked. Next, the ears of the negative electrode plate of the laminate were connected to each other with a strap, and the ears of the positive electrode plate were connected to each other with a strap to obtain an unformed element. Six sets of elements are housed in series in a battery case, water is added, and dilute sulfuric acid containing aluminum ions in the range of 0 to 0.3 mol / L and lithium ions in the range of 0 to 0.3 mol / L is added. A lead-acid battery of the Q-55 type was obtained by forming a battery with a quantity of electricity according to In addition, it may replace with battery case formation and tank formation etc. may be performed.

  Aluminum ions were added as aluminum sulfate and lithium ions were added as lithium sulfate. However, the addition form is arbitrary as long as it is a salt, oxide, hydroxide or the like soluble in dilute sulfuric acid. In addition to dilute sulfuric acid, aluminum ions, and lithium ions, the electrolytic solution may contain, for example, 0.02 mol / L or less of sodium ions, potassium ions, magnesium ions, and the like. Each storage battery was produced by processing the same material under the same conditions except that the mass ratio of active material, aluminum ion concentration, and lithium ion concentration were different. The electrolytic solution injected into the battery case is a solution in which aluminum sulfate and lithium sulfate are dissolved in dilute sulfuric acid having a specific gravity of 1.230 at 20 ° C.

  Three lead storage batteries were prepared for each mass ratio of the negative electrode active material to the positive electrode active material and the combination of the aluminum ion and lithium ion contents of the electrolyte, and are defined in 9.5.2b) of JIS D 5301: 2006 5 The time rate capacity (5 hR capacity) was measured, and then a high rate discharge characteristic test specified in JIS D 5301: 2006 9.5.3b) was performed. In the high rate discharge characteristic test, the time until the terminal voltage drops to 6V is measured while discharging at a predetermined current value in an environment of -15 ° C. Since this is for testing high rate discharge performance at low temperature, it was conducted as a test for low temperature high rate discharge performance. Next, an idle stop life test of SBA S 0101: 2006, which is a standard of the battery industry association, was performed. In the idling stop life test, a cycle consisting of 59 seconds at 45A and 1 second at 300A and 60 seconds at a charging voltage of 14V (limit current 100A) is performed, and left for 40 to 48 hours every 3600 cycles. . When the terminal voltage becomes less than 7.2V during 300A discharge, it is considered as the life. Here, the conditions for the idling stop life test were changed, the lead storage battery was disassembled after 18,000 cycles, and the amount of lead sulfate accumulated in the negative electrode was measured.

  As described above, the 5 hR capacity, the low temperature high rate discharge duration, and the amount of lead sulfate accumulated on the negative electrode were measured. The performance of each lead storage battery is shown in Table 1 as a relative value with the performance of the sample A1 of the comparative example having a mass ratio of the negative electrode active material and the positive electrode active material being 100% as an average value of three batteries Show.

  As is clear from Table 1, when the mass ratio between the negative electrode active material and the positive electrode active material is smaller than 1, the 5hR capacity increases, and the 5hR capacity becomes maximum when the mass ratio is 0.75 and is particularly large at 0.7 or more and 0.85 or less. 5hR capacity is obtained. However, in an electrolyte solution containing neither aluminum ions nor lithium ions, the low-temperature high-rate discharge performance and the idling stop life performance are lowered by making the mass ratio less than 1. On the other hand, for example, when 0.1 mol / L of aluminum ions and lithium ions are contained in the electrolytic solution, the low-temperature high-rate discharge performance and the idling stop life performance are improved. For example, if the electrolyte contains 0.1 mol / L each of aluminum ions and lithium ions, combining the low-temperature high-rate discharge performance and idling stop life performance of samples with a mass ratio of 0.85 or less and 0.6 or more, the electrolyte is aluminum It is equivalent to sample A3 containing 0.1 mol / L each of ions and lithium ions and having a mass ratio of 0.9. Therefore, in the example based on the sample A3 of the comparative example, the 5 hR capacity is increased while maintaining the low temperature high rate discharge performance and the idling stop life performance.

  Examining the effect of aluminum ion concentration, 0.01 mol / L as in sample A7 is insufficient to improve the idling stop life performance, and 0.02 mol / L as in sample A8, the idling stop life performance is significantly improved. The Therefore, the aluminum ion concentration is 0.02 mol / L or more. On the other hand, when the aluminum ion concentration is 0.3 mol / L as in sample A10, the low-temperature high-rate discharge performance is remarkably lowered, and the idling stop life performance is peak. Therefore, the aluminum ion concentration is 0.02 mol / L or more and 0.2 mol / L or less.

  Examining the effect of lithium ion concentration, the low temperature high rate discharge performance is insufficient at 0.01 mol / L as in sample A11, and the low temperature high rate discharge performance is significantly improved at 0.02 mol / L as in sample A12. The Accordingly, the lithium ion concentration is set to 0.02 mol / L or more. Increasing the lithium ion concentration from 0.02 mol / L to 0.2 mol / L improves the low-temperature, high-rate discharge performance, but exceeding 0.2 mol / L does not improve the performance of the storage battery (Samples A14 and A15) . Therefore, the lithium ion concentration is set to 0.02 mol / L to 0.3 mol / L, preferably 0.02 mol / L to 0.2 mol / L.

  As seen in Sample A29, if the mass ratio of the negative electrode active material to the positive electrode active material is reduced to 0.55, even if each 0.1 mol / L aluminum ion and lithium ion are contained, the low temperature high rate discharge performance is insufficient. It becomes. This is presumably because the mass ratio of the negative electrode active material and the positive electrode active material was too small, and the chemical conversion property of the positive electrode active material was lowered.

  In the present invention, it is possible to increase the capacity such as the 5-hour rate capacity of the lead storage battery while maintaining the idling stop life performance.

The present invention relates to a lead-acid battery comprising a positive electrode plate, a negative electrode plate, a polyethylene porous separator, and a liquid electrolyte containing sulfuric acid and aluminum ions, and a negative electrode active material for the negative electrode plate and a positive electrode active material for the positive electrode plate a mass ratio of 0.7 to 0.85 and, and aluminum ion concentration in the electrolyte 0.02 mol / L or more 0.2 mol / L Ri der hereinafter the electrolyte lithium ion concentration is less than 0.01 mol / L characterized in that there.

According to the inventor's experiment, the mass ratio between the negative electrode active material and the positive electrode active material is 0.6 or more and 0.85 or less, and the aluminum ion concentration in the electrolytic solution is 0.02 mol / L or more and 0.2 mol / L or less. A lead-acid battery having a large capacity such as a time rate capacity and a small amount of lead sulfate accumulated in the negative electrode can be obtained. When the influence of each element is examined individually, the capacity of the storage battery is increased by setting the mass ratio of the negative electrode active material and the positive electrode active material to 0.85 or less. On the other hand, when the mass ratio of the negative electrode active material to the positive electrode active material is less than 0.6, the low-temperature high-rate discharge performance is degraded. Therefore, the mass ratio of the negative electrode active material to the positive electrode active material is set to 0.6 or more. Furthermore, when the mass ratio of the negative electrode active material to the positive electrode active material is 0.7 or more, the capacity of the lead storage battery such as the 5-hour rate capacity can be particularly increased, so this mass ratio is set to 0.7 or more and 0.85 or less.

The lithium ion concentration in the electrolyte is 0.01 mol / L or less .

Examining the effect of lithium ion concentration, the low temperature high rate discharge performance is insufficient at 0.01 mol / L as in sample A11, and the low temperature high rate discharge performance is significantly improved at 0.02 mol / L as in sample A12. The Increasing the lithium ion concentration from 0.02 mol / L to 0.2 mol / L improves the low-temperature, high-rate discharge performance, but exceeding 0.2 mol / L does not improve the performance of the storage battery (Samples A14 and A15) . However, an electrolyte containing lithium ions exceeding 0.01 mol / L is not included in the present invention.

Claims (3)

In a lead storage battery comprising a positive electrode plate, a negative electrode plate, and an electrolyte containing sulfuric acid and aluminum ions,
The mass ratio of the negative electrode active material of the negative electrode plate to the positive electrode active material of the positive electrode plate is 0.6 or more and 0.85 or less, and the aluminum ion concentration in the electrolyte is 0.02 mol / L or more and 0.2 mol / L or less. Lead acid battery.   The lead acid battery according to claim 1, wherein the electrolyte has a lithium ion concentration of 0.01 mol / L or less.   The lead acid battery according to claim 1 or 2, wherein a mass ratio of the negative electrode active material to the positive electrode active material is 0.7 or more and 0.8 or less.