JP4509660B2 - Lead acid battery - Google Patents

Description

  The present invention relates to a lead-acid battery.

Traditionally, lead-acid batteries for automobiles, called SLI batteries, have been used as a power source for motors that have been installed in more than 100 high-end cars, including starter start-up, lighting, and ignition at start-up. Since the engine drives the generator to supply power except for starting the starter at that time, the lead-acid battery was not discharged so deeply. Moreover, since the lead storage battery is often placed in a fully charged state by charging from a generator, it has been required to be resistant to overcharging. At the same time, the lead storage battery is required to have a maintenance-free property that suppresses the decrease in the electrolyte due to gas generation during overcharge and eliminates the need for rehydration. The alloy constituting the porous substrate of the positive electrode is made of Pb—Sb alloy to Pb. -Changed to Ca alloy.
In recent years, automobiles are strongly required to improve fuel consumption and reduce exhaust gas. With this, the usage conditions of lead-acid batteries using an alloy substrate made of a Pb-Ca alloy as a positive electrode porous substrate have changed greatly. I came. That is, one of the use conditions is an idling stop that stops the engine while the vehicle is stopped by a signal or the like. Since the power supply from the generator is also stopped when the engine is stopped, the electric power during this time is provided by the discharge of the lead storage battery. Therefore, it has been deeply discharged compared to the conventional case. As a result, the lead-acid battery was used in a deep charge / discharge state, and the life was significantly shortened. One of the causes is that the positive electrode substrate alloy is changed from a Pb—Sb alloy to a Pb—Ca alloy.
That is, when the positive electrode substrate alloy is a Pb—Sb alloy, pentavalent Sb ions generated by oxidation of the substrate form a strong α-PbO ₂ layer at the interface between the substrate and the active material, While maintaining the adhesion of the active material, high conductivity was ensured. In addition to this, pentavalent Sb ions act on the active material to gel a part thereof, thereby strengthening the bonding between the active material particles.
On the other hand, when the positive electrode substrate alloy is a Pb—Ca alloy, the binder action as seen in Sb is weak, and the interface between the substrate and the active material is peeled off and sulfuric acid as an electrolyte enters. As a result, lead sulfate, which is a non-conductor, was produced and the conductivity was significantly impaired. Further, when left in a discharged state, a phenomenon that the capacity is not recovered due to the same cause appeared. Further, when deep charge / discharge was repeated, the active material softened and reached the end of life about half the number of times when the Pb—Sb alloy was used.
Therefore, for the purpose of obtaining a binder effect similar to that obtained when a Pb-Sb alloy is used for a positive electrode plate made of a Pb-Ca alloy having such disadvantages, for example, JP-A-49-71429. In Japanese Patent Laid-Open No. 63-148556, Sb is attached to a formed anode plate. In Japanese Patent Laid-Open No. 53-75444, a positive electrode including a storage body that releases antimony in a positive electrode active material is disclosed in Japanese Patent Laid-Open No. Therefore, it has been proposed to form a Pb—Sb—Sn alloy layer on at least one surface of the Pb—Ca alloy lattice. These additions of Sb according to the disclosed invention achieved the above objectives. However, the application of Sb, although a trace amount, lowered the hydrogen overvoltage of the negative electrode, resulting in a decrease in the electrolyte due to gas generation during charging, and the maintenance-free property was impaired.
Furthermore, in order to solve the above-mentioned problem of imparting Sb to such a Pb—Ca-based alloy, the interface between the substrate and the active material and the binding force between the active material particles are the same as those of Sb without imparting Sb. An invention relating to a lead storage battery that is maintained and has maintenance-free properties has been proposed in Japanese Patent Laid-Open No. 3-145061.
The invention described in this publication uses a lattice body in which a lead-bismuth-based alloy layer is provided on at least a part of a lattice base material for a positive electrode, thereby improving the life characteristics of repeating deep discharge while maintaining maintenance-free properties. Although it was measured, the effect of improving the binding property between the interface between the substrate and the active material and the active material particles was insufficient.
On the other hand, a non-antimony-based lead alloy containing tin is used as a lattice and an alkali metal ion is added to the electrolyte for the purpose of improving capacity recovery by charging a lead storage battery left for a long time after discharge. A lead-acid battery characterized by being present and a non-antimony alloy containing Ca and Sn as a lattice body, and an alkaline earth metal ion and an alkali metal ion coexist in the electrolytic solution, and at the lattice-active material interface Lead storage batteries characterized by forming an α-PbO ₂ film are disclosed in Japanese Patent Publication No. 57-32873, Japanese Patent Publication No. 7-242243, and the like.
However, although the inventions disclosed in these documents have achieved the above-mentioned object, further effects such as adhesion at the interface between the substrate and the active material and the binding property between the particles of the active material can be obtained. There wasn't.
The inventor of the present application first specifies the content of each of Ca, Sn, Al, and Ba in Japanese Patent Application Laid-Open No. 2003-306733 as a Pb—Ca-based alloy for a lead-acid battery substrate. A lead alloy for lead-acid batteries and a lead-base alloy further containing at least one selected from a specific amount of silver, bismuth, and thallium, respectively. An invention relating to a lead-acid battery using an ordinary electrolyte filled with an active material has been disclosed. However, in the present invention, an alloy substrate having both improved corrosion resistance and mechanical strength using these lead-based alloys, and in addition to such characteristics, it is stable and long-term even under severe conditions at high temperatures. A lead storage battery that can withstand use can be provided, but as a result of testing, the lead alloy lattice has a high corrosion resistance. The binding was found to be low.
JP-A-49-71429 Japanese Patent Laid-Open No. 53-75444 JP-A 63-148556 Japanese Patent Laid-Open No. 3-145061 Japanese Patent Publication No.57-32873 JP-A-4-206150 JP 2003-306733 A

The present invention eliminates the disadvantages of the inventions described in Patent Documents 1 to 7 above, uses a Pb—Sb alloy porous substrate, and has good adhesion between the porous substrate and the active material and good bonding between the active material particles. , and the and maintaining maintenance-free property乍Ra, and an object thereof is to provide a lead-acid battery with improved cycle life and capacity recovery.

The present invention provides a lead-acid battery that achieves the above-mentioned object. As described in claim 1, a positive electrode plate comprising a porous substrate made of a Pb-Ca alloy and filled with a positive electrode active material containing calcium. And a combination of an electrolytic solution containing aluminum ions.
The present invention, in the above invention, by comprising a combination of an electrolytic solution containing a positive electrode and A Rumi ion formed by filling a positive electrode active material containing calcium and tin into a porous substrate made of Pb-Ca alloy Features.

According to the present invention, as will be clarified later, lead is obtained by combining a positive electrode plate made by filling a positive electrode active material containing calcium on a porous substrate made of a Pb-Ca alloy and an electrolyte containing aluminum ions. When forming a storage battery, a lead storage battery comprising a combination of a positive electrode plate formed by filling a porous substrate made of a Pb-Ca alloy with a positive electrode active material not containing calcium and an electrolytic solution not containing aluminum ions, Pb-Ca Lead-acid battery in which a positive electrode plate made by filling a porous substrate made of an aluminum alloy with a positive electrode active material containing calcium and an electrolytic solution not containing aluminum ions, or calcium on a porous substrate made of a Pb-Ca alloy Compared to lead-acid batteries, which are a combination of a positive electrode plate filled with a positive electrode active material not contained and an electrolyte containing aluminum ions, And improved capacity recovery property, lead-acid battery is obtained and has a maintenance-free property.
Further, in the present invention, when a positive electrode plate obtained by filling a porous substrate made of a Pb—Ca alloy with a positive electrode active material containing calcium and tin is combined with an electrolytic solution containing aluminum ions , lead-acid battery having a maintenance-free properties of cycle life and the capacity recovery property is further improved Ru obtained.

As a porous substrate such as a lattice used for manufacturing the positive electrode of the lead storage battery of the present invention, a conventionally known lead-based alloy made of various Pb—Ca alloys can be selected and used. In addition, when using the Pb—Ca alloy disclosed in Patent Document 7 above, a lead storage battery having excellent corrosion resistance and mechanical strength, and being able to withstand long-term use stably under high temperature and severe conditions. Can be manufactured. In addition, an electrode substrate can be manufactured by a desired method such as a gravity casting method, a continuous casting method, a rolling / working method using the lead-based alloy for a lead-acid battery. An embodiment will be described.
That is, in more detail, an electrode substrate such as a lattice substrate is manufactured using the above-described desired manufacturing method using the Pb—Ca alloy having excellent corrosion resistance and mechanical strength as a material. The alloy composition is 0.02 wt% or more and less than 0.05 wt% calcium, 0.4 wt% or more and 2.5 wt% or less of tin, and aluminum is 0.005 wt% or more and 0.04 wt%. % Or less, barium is 0.002% by weight or more and 0.14% by weight or less, and the balance is lead. Hereinafter, this is referred to as a first substrate.
In addition to the above compositional alloy, 0.005 wt% or more and 0.07 wt% or less silver, 0.01 wt% or more and 0.10 wt% or less bismuth, 0.001 wt% or more and 0.05 wt% or more. By including at least one selected from thallium or less of% or less, it is possible to obtain a porous substrate with further improved mechanical strength and improved creep rupture strength at high temperature. Hereinafter, this is referred to as a second substrate.

  According to one embodiment of the present invention, a porous substrate such as a lattice body made of a conventional desired Pb—Ca alloy is preferably filled in the pores of the porous substrate of the first substrate or the second substrate. At least one kind of powder selected from salts such as sulfate, carbonate, bicarbonate, phosphate, borate, etc. is added to and mixed with normal cathode active material, that is, lead powder for cathode as calcium The calcium-containing positive electrode active material prepared by caulking is filled to produce the positive electrode plate of the present invention. In such a case, calcium can secure a conductivity between the porous substrate and the interface between the active materials and improve adhesion, and at the same time, a positive electrode plate with improved binding between the active material particles can be obtained. Hereinafter, this is referred to as a first positive electrode plate.

Further, according to another embodiment of the present invention, at least one powder of the above calcium material and metal in the same positive electrode active material as above in the pores of the porous substrate made of the same Pb-Ca alloy as described above. Among the tin materials composed of tin compounds such as tin and tin salts, the positive electrode active material containing both components prepared by adding and mixing at least one kind of powder, for example, tin sulfate powder, is filled, The positive electrode plate of the present invention is prepared. This is a second positive electrode plate. In such a case, as will be clarified later, when the second positive electrode plate is used, a positive electrode plate having an effect further improved as compared with the first positive electrode plate can be obtained. Although the reason for the improvement of the positive electrode plate as described above is not clear, calcium is inferior to antimony but has a function of stabilizing α-PbO ₂ at the substrate-active material interface. In the case where tin coexists therewith, it is considered that the same effect is produced when tin is doped to improve conductivity and substantially improve the adhesion at the interface, and α-PbO ₂ doped with calcium is an oxidation catalyst. This is thought to be due to the stabilization of highly conductive SnO ₂ . Also for the active material particles, the surface that reacts with the sulfuric acid aqueous solution that is the electrolytic solution is β-PbO ₂ , but since the inside is α-PbO _2, it is considered that there are similar effects. Further, since neither calcium nor tin has an effect of impairing maintenance-free properties like antimony, a maintenance-type lead storage battery can be obtained advantageously using the first positive electrode plate or the second positive electrode plate.

  Furthermore, according to the present invention, as described above, while preparing the first positive electrode plate or the second positive electrode plate, as a sulfuric acid electrolytic solution used for a lead storage battery, an aluminum material such as aluminum sulfate is added to the electrolytic solution. An electrolytic solution containing the aluminum ions is prepared by dissolution. In order to prepare such an electrolytic solution, various aluminum compounds soluble in an electrolytic solution such as metallic aluminum and aluminum sulfate are used as an aluminum material, and this is added to and dissolved in a normal sulfuric acid electrolytic solution to obtain the aluminum ion of the present invention. A containing electrolyte solution is prepared. The effect of aluminum ions is not clear, but it is not limited to suppressing the decrease in the sulfate ion concentration in the electrolyte when left in a discharge, and the lead sulfate crystals produced on the positive and negative electrodes are coarsened and densified. It has the effect of suppressing and significantly improving the charge acceptance at the time of recovery charging, and particularly when the lead storage battery is manufactured in combination with the first positive electrode plate or the second positive electrode plate of the present invention, its cycle life. And a significant improvement in capacity recovery.

  That is, according to the present invention, a positive electrode plate is formed by filling a porous substrate made of a PB-Ca alloy with, for example, a positive electrode active material containing calcium or calcium and tin in the first substrate or the second substrate. By constructing a lead storage battery comprising a combination of one positive electrode plate or second positive electrode plate and an electrolyte solution containing aluminum ions as a sulfuric acid electrolyte solution, as will be clarified later, calcium is used as the active material. Lead acid battery comprising a positive electrode plate not containing tin and tin and a sulfuric acid electrolyte solution not containing aluminum ions, a positive electrode plate containing calcium or calcium and tin in the filled positive electrode active material, and a sulfuric acid electrolyte solution not containing aluminum ions Lead acid battery and a positive electrode plate containing no calcium or calcium and tin in the active material and sulfuric acid containing aluminum ions Compared to lead-acid battery comprising a combination of a solution liquid, it is possible allowed to significantly increase both the capacity recovery characteristics after left in the cycle life and long discharge state, the lead-acid battery is obtained maintainability is maintained.

Next, detailed examples of the present invention will be described together with comparative examples.
As the porous substrate made of a Pb—Ca alloy, the alloy belonging to the second substrate, that is, the alloy composition is 0.04% by weight of calcium, 1.0% by weight of tin, 0.015% by weight of aluminum, 0. A cast-type substrate by a book mold was manufactured using an alloy consisting of 008 wt%, bismuth 0.05 wt%, the balance lead and inevitable materials. Casting was performed at a rate of 15 sheets per minute. The cast substrate was heat-treated at 120 ° C. for 3 hours and age hardened.
On the other hand, as shown in the following Table 1, calcium sulfate alone or calcium sulfate and tin sulfate are added to the lead powder for the positive electrode in various amounts, and various positive electrode active materials are added and mixed. Each of the positive electrode pastes produced and prepared by a known method is filled in each of the porous substrates obtained by the age-hardening treatment, and then heated in an atmosphere of 40 ° C. and 95% humidity for 24 hours, followed by drying. Thus, each positive electrode unformed plate was produced. As shown in Table 1 below, each electrode plate group formed by combining a negative electrode non-formed plate and a polyethylene separator produced by a known method is housed in each battery case. Then, after injecting each sulfuric acid electrolyte solution prepared by changing the addition amount from the one not added with aluminum sulfate, formation of a battery was performed, and a D23 size 12V battery with a 5-hour rate capacity of 50 Ah was produced.
In addition, the quantity of calcium and tin shows the addition amount in metal conversion, and aluminum shows the addition amount in sulfate conversion.
Using these batteries, a heavy load test was performed in accordance with JIS D 5301, and the cycle life (number of times) was measured. Separately from this, each of the above batteries was subjected to a discharge standing test at 60 ° C. for 4 weeks, and the capacity recoverability (%) after discharge was measured. The results are shown in Table 1.

In Table 1, it is clear from Comparative Example 1 that the cycle life and capacity recoverability of a lead storage battery comprising a combination of a positive electrode plate containing no calcium and tin and a sulfuric acid electrolyte containing no aluminum ions are the lowest. . Moreover, it turns out that aluminum, calcium, and tin do not contribute to the improvement effect of a cycle life and capacity | capacitance as a component of a Pb-Ca-type alloy substrate.
Further, as is clear from Comparative Example 2, when combined with a positive electrode containing calcium in the active material and an electrolytic solution not containing aluminum ions, it is recognized that the cycle life is somewhat improved when compared with Comparative Example 1. .
As is clear from Comparative Example 3, when the positive electrode containing tin and the electrolytic solution not containing aluminum ions are combined in the active material, the capacity recovery is slightly improved when compared with Comparative Example 1, but the cycle There is no improvement in life.
Further, from Comparative Example 4, even when aluminum is added to the electrolytic solution, if calcium or / and tin are not added to the positive electrode active material, no improvement in cycle life is observed, and there is almost no improvement effect on capacity recovery. I understand that.
Further, it can be seen from Comparative Example 5 that even when calcium and tin are added to the positive electrode active material, when aluminum ions are not present in the electrolytic solution, no significant improvement in cycle life and capacity recoverability is observed.
On the other hand, as apparent from Examples 1 to 13, cycle life and capacity recoverability are started only by adding calcium alone or both calcium and tin to the positive electrode active material and adding and dissolving an aluminum material in the electrolyte. It can be seen that there is a marked improvement in both.
Further, as apparent from Examples 3 to 5, when the addition amount of aluminum is made constant and the addition amount of calcium and tin is increased, an improvement in cycle life and capacity recoverability is observed with the increase. I understand.
Thus, the positive electrode plate using the Pb-Ca-based alloy substrate used in the above-described examples of the present invention has the above-described properties of having excellent corrosion resistance, mechanical strength, and creep rupture strength at high temperatures. It can be seen that the combination of the positive electrode active material containing the additive of the present invention and the electrolytic solution can improve the cycle life and capacity recovery, and provide a lead-acid battery maintaining maintenance-free characteristics.

The aluminum material as the additive has been shown in the case where the sulfate is added, but any compound that is soluble in an aqueous sulfuric acid solution or water may be used. For example, the respective carbonate, bicarbonate, phosphorus It can be added as a compound such as acid salt, borate, hydroxide, aluminate. Further, calcium and tin as additives may be respective oxides. Moreover, you may add these as the aqueous solution.
In addition, the addition amount of calcium is preferably 1.5% by weight or less with respect to the positive electrode active material in terms of metal. When it exceeds 1.5% by weight, the utilization factor and the discharge voltage tend to decrease. The amount of tin added is preferably 1.0% by weight or less with respect to the positive electrode active material in terms of metal, as in the case of calcium. The amount of aluminum added is preferably 2 to 50 g or less per 1 liter of sulfuric acid electrolyte in terms of sulfate. When it exceeds 50 g / l, the electric conductivity is lowered, and a tendency to deteriorate the rapid discharge characteristics at low temperature is recognized.

  In addition, using the above-mentioned second substrate or an alloy substrate made of a Pb—Ca—Sn alloy, these porous substrates are made to contain calcium alone or both components of calcium and tin in the same manner as in the above examples. When each lead storage battery is configured to include each positive electrode plate filled with a positive electrode active material and a sulfuric acid electrolyte solution containing aluminum in the above-mentioned addition amount in the same manner as in the above embodiment. The same results as in the above example were obtained.

  As described above, as is apparent from the test results, the positive electrode plate in which the positive electrode active material mixed with calcium or calcium and tin is filled in the porous substrate made of the Pb-Ca alloy and the aluminum ion added and dissolved are included. The lead storage battery comprising the electrolytic solution provides a lead storage battery having a long life and improved capacity recovery after being left for a long time while maintaining maintenance-free properties. Thus, the lead-acid battery of the present invention maintains maintenance-free properties, and has superior capacity recovery after being left in a charge / discharge cycle life or discharge state for a long period of time compared to the conventional case. Longer life is achieved in deep DOD applications such as cycle use, and in particular, it can be applied to lead-acid batteries for automobiles and can contribute to the expansion of the use of lead-acid batteries.

Claims (2)

  A lead-acid battery comprising a combination of a positive electrode plate formed by filling a porous substrate made of a Pb-Ca alloy with a positive electrode active material containing calcium and an electrolytic solution containing aluminum ions. Lead according to claim 1, characterized by comprising a combination of an electrolytic solution containing a positive electrode and A Rumi ion formed by filling a positive electrode active material containing calcium and tin into a porous substrate made of pb-Ca alloy Storage battery.