JP6332670B2 - Method for producing lead-acid battery - Google Patents

Description

  The present invention relates to a method for manufacturing a lead storage battery.

  Lead storage batteries are widely used because of their reliability, low price, and the like, and in particular, there is a great demand for lead storage batteries for automobiles, so-called batteries.

  The appearance of a lead storage battery (hereinafter referred to as a battery) is shown in FIG. In the battery, the battery case 1 and the lid 2 are thermally welded, and two terminals 3 (for positive electrode and for negative electrode) project from the upper surface of the lid 2. The battery case 1 is hollow and is divided into six sections (cells) by partition walls. Each cell accommodates a group of electrode plates formed by alternately laminating positive electrode plates, separators, and negative electrode plates and welding current collecting portions of the same polarity. A liquid injection port 4 is provided on the upper surface of the lid 2 corresponding to each of the compartments.

  In order to make the battery usable, that is, ready for charging and discharging, container formation is required. This is a process of injecting a predetermined amount of dilute sulfuric acid having a specific gravity from the injection port 4 of FIG. 1, connecting an electric wire to the terminal 3, and applying a direct current. This is by electrolyzing an unformed positive electrode plate and negative electrode plate in dilute sulfuric acid and changing the unformed active material of the positive electrode plate to lead dioxide and the unformed active material of the negative electrode plate to spongy lead by oxidation / reduction. Is. Battery case formation is an important process for generating an active material that determines the charging performance and discharging performance of a battery.

  Since lead-acid batteries for automobiles are mass-produced products, improvement in production efficiency is required. Battery case formation is required to be completed in as short a time as possible. For this reason, it is common to energize a battery case by passing a large current, but the battery generates heat due to reaction heat. As a result, a desired active material could not be generated, resulting in a decrease in battery performance.

  As the above countermeasure, Patent Document 1 proposes an invention that suppresses heat generation of the battery by energizing the battery case and repeating ON-OFF at short time intervals to improve the initial capacity of the battery.

Japanese Patent Laid-Open No. 5-121069

  In recent years, automobiles that have introduced an idling stop start (hereinafter referred to as ISS) system have been put into practical use due to increasing environmental awareness. Automobiles that have introduced the ISS system stop the engine while the vehicle is temporarily stopped. For this reason, electrical components such as air conditioners must be driven by batteries while the engine is temporarily stopped. In addition, the battery must start the engine more frequently than the conventional automobile in order to stop the engine while waiting for a signal and repeat the subsequent engine start. Then, since the discharge amount of the battery increases from the charge amount by the engine, the battery becomes in a state of insufficient charge, resulting in a short life. Therefore, the ISS battery is required to have charging performance, particularly charge acceptance performance.

  In the invention of Patent Document 1, although the initial capacity is increased, that is, the discharge performance is improved, the charge performance is not improved.

  An object of this invention is to provide the manufacturing method of the lead storage battery which reviewed the battery case formation process and improved charge acceptance performance.

Therefore, the present invention has the following configuration in order to solve the above problems.
In a battery formation in which dilute sulfuric acid is injected into a lead-acid battery including a positive electrode plate containing an unformed positive electrode active material and a negative electrode plate containing an unformed negative electrode active material, and direct current is passed, A time zone in which energization is stopped is set in each of the first stage in which the applied amount is between 40 and 80% and the second stage in which the applied amount is between 125 and 165%. Time to stop the energization, to energized to 0.5-1.5 hours der respectively is, voltage application amount resume energization after a time period to stop the energization in said second step is greater than 165% It is characterized by that.

  Conventionally, due to the rise in battery temperature, the charge acceptance performance has been reduced due to a decrease in the specific surface area (by the BET method) of the positive electrode active material (lead dioxide) after conversion. As described above, the temperature rise of the battery can be suppressed by stopping energization for a predetermined time at a predetermined stage during the formation of the battery case. As a result, a decrease in the specific surface area of the positive electrode active material (lead dioxide) after chemical conversion is suppressed, and a decrease in charge acceptance performance can be suppressed.

  As mentioned above, according to this invention, the manufacturing method of the lead acid battery which improved charge acceptance performance can be provided.

It is a perspective view which shows the external appearance of a lead storage battery.

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

(Production of electrode plate)
First, a predetermined amount of calcium and tin are dissolved in lead so as to have a predetermined alloy composition. A slab is produced by casting the lead alloy in a mold. The slab is continuously rolled to produce a rolled lead alloy sheet.
Next, slits in the longitudinal direction of the rolled lead alloy sheet are sequentially inserted in both the left and right regions excluding the central portion in the width direction of the rolled lead alloy sheet, and then expanded (expanded) in the width direction of the rolled lead alloy sheet. A grid is formed. While cutting this to a predetermined dimension, the undeveloped portion at the center in the width direction of the rolled lead alloy sheet is punched to obtain an expanded lattice.
Next, water and dilute sulfuric acid are added to and kneaded with lead powder containing lead oxide as a main component to produce a paste active material for a positive electrode. This pasty active material is filled into an expanded lattice, and a positive electrode plate is produced through aging and drying. The active material at this time is called an unformed positive electrode active material.
Similarly, an additive (lignin, barium sulfate, carbon material) is added to and mixed with lead powder containing lead oxide as a main component, and then water and dilute sulfuric acid are added and kneaded to prepare a paste active material for a negative electrode. Is made. This paste-like active material is filled in the network part of the expanded lattice, and aging and drying are performed to produce a negative electrode plate. The active material at this time is referred to as an unformed negative electrode active material.

(Production of bag-shaped separator)
The polyethylene porous sheet is cut into a predetermined size and folded in half. Subsequently, both side edges are joined by heat welding or mechanical seal to produce a bag-like separator.

(Battery assembly)
A negative electrode plate is inserted into the bag-shaped separator. The negative electrode plate accommodated in this bag-like separator is alternately combined with the positive electrode plate to produce an electrode plate group of 6 positive electrode plates / 7 negative electrode plates. Subsequently, the current collectors of the positive electrode plate and the negative electrode plate are welded by a cast-on strap (COS) method to form an electrode plate group. The six electrode plate groups are housed in a polypropylene battery case 1 shown in FIG. 1, and a lid 2 is placed over the battery case 1 and thermally welded.

(Battery formation)
The battery is placed in an empty water tank and immersed in water up to about 80% of the battery height. A heater is installed in the aquarium so that the temperature can be controlled even in cold conditions such as in winter. In addition, a water flow pump is placed in the water tank to create a circulating water flow, and the temperature in the water tank is made uniform. Water tank temperature is managed at 38-42 degreeC suitable for chemical conversion reaction.
Dilute sulfuric acid is injected from an injection port 4 provided in the lid 2. The specific gravity of the diluted sulfuric acid to be injected is 1.230 (converted to 20 ° C., the same applies hereinafter), and the injection volume is 630 ml / cell. The temperature of the diluted sulfuric acid to be injected is not particularly limited, but is preferably close to the water bath temperature. When injected, the dilute sulfuric acid permeates into the porous unformed active material, and at the same time, the dilute sulfuric acid and the unformed active material react to generate heat.
The battery after injection is allowed to stand for about 0.5 to 1 hour before energization is started. This is because it takes a certain amount of time for the dilute sulfuric acid to penetrate into the unformed active material. In the case of standing for more than 1 hour, the reaction between the dilute sulfuric acid and the unformed active material proceeds excessively, and an unformed active material that is not easily oxidized / reduced is formed.
An electric wire (not shown) is connected to the terminal 3 of the battery after standing, and a direct current is applied for a predetermined time to form a battery case. As will be described in detail below, a time zone during which no energization is performed for a predetermined time is provided in each of the first stage in which the amount of power applied reaches a predetermined value and the subsequent second stage. After the formation of the battery case, the electrolyte specific gravity is adjusted to 1.280, and a 75D23 battery according to JIS D5301 is manufactured.

(Electricity charged)
The amount of electricity defined in the present invention is the ratio of the amount of electricity charged during formation of the battery case (energization current A × energization time h = Ah) to the theoretical electric capacity (Ah) of the positive electrode active material. Is%. Usually, since the unformed positive electrode active material is more electrolyzed than the unformed negative electrode active material, the ratio of the amount of charge to the theoretical electric capacity of the positive electrode active material is adopted.

  The theoretical electric capacity is obtained by multiplying the amount of unformed positive electrode active material (g) in the electrode plate group by the unit theoretical capacity 4.463 (Ah / g).

(Evaluation test)
The procedure for evaluating the charge acceptability of an ISS battery is shown below. A battery in a fully charged state, that is, SOC (State of Charge) 100% is placed in an ambient temperature of 25 ° C., and after the battery temperature is stabilized, it is discharged at a current rate of 5 hours to reach a state of SOC 90%. Subsequently, the battery is charged at a constant voltage with a voltage of 14.0 V and a limiting current of 100 A, and the charge acceptability is evaluated by the amount of charged electricity up to 5 seconds after the start of charging.

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

Example 1
After the injected battery is allowed to stand for 1 hour, a direct current (current value 23 A) is applied. As a first step, the energization is stopped for 0.5 hours when the amount of electric charge reaches 40% (2.5 hours after the energization starts). The energization is resumed after the stop, and the energization is stopped for 0.5 hours at the time when the applied amount reaches 125% (8 hours after the energization is started) as the second stage. The energization is resumed after the stop, and the energization is terminated when the power application amount reaches 250%. At this time, the energization time is 16 hours in total, and the energization stop time is 1 hour in total. After the formation of the battery case, the specific gravity of the electrolyte was adjusted to 1.280.

(Examples 2-9)
A battery was fabricated in Example 1 with the energization stop time after the first stage and the energization stop time after the second stage set as shown in Table 1, respectively.

(Examples 10 to 17)
In Example 1, the battery was manufactured with the amount of power applied as 60% as the first stage, and the energization stop time after the first stage and the energization stop time after the second stage as set in Table 1.

(Examples 18 to 26)
In Example 1, the battery was manufactured by setting the amount of power application as 80% as the first stage and setting the energization stop time after the first stage and the energization stop time after the second stage as set in Table 1.

(Examples 27 to 35)
In Example 1, the amount of electricity charged was 60% as the first stage, the amount of electricity charged was 145% as the second stage, and the energization stop time after the first stage and the energization stop time after the second stage were set as shown in Table 1. Was made.

(Examples 36 to 44)
In Example 1, the amount of electricity charged was 60 as the first stage, the amount of electricity charged was 145% as the second stage, and the energization stop time after the first stage and the energization stop time after the second stage were set as shown in Table 2. Produced.

(Examples 45-53)
In Example 1, the battery is assumed to have a power application amount of 80% as the first stage, a power application quantity of 145% as the second stage, and the energization stop time after the first stage and the energization stop time after the second stage as set in Table 2. Was made.

(Examples 54 to 62)
In Example 1, the battery was manufactured by setting the amount of electricity applied as 165% as the second stage, and setting the energization stop time after the first stage and the energization stop time after the second stage as set in Table 2.

(Examples 63 to 71)
In Example 1, the amount of electricity applied was 60% as the first stage, the amount of electricity applied was 165% as the second stage, and the energization stop time after the first stage and the energization stop time after the second stage were set as shown in Table 2. Was made.

(Examples 72 to 80)
In Example 1, the amount of electricity applied was 80% as the first stage, the amount of electricity applied was 165% as the second stage, and the energization stop time after the first stage and the energization stop time after the second stage were set as shown in Table 3. Was made.

(Comparative Example 1)
After the injected battery is allowed to stand for 1 hour, a direct current (current value 23 A) is continuously energized. The energization is terminated when the amount of electric charge reaches 250% (16 hours). A battery having an electrolyte specific gravity adjusted to 1.280 after the formation of the battery was prepared.

  If the energization is stopped before the amount of electric charge reaches 40% as the first stage, the reaction heat of dilute sulfuric acid and the unformed active material and the resistance heat generation due to the energization are not yet stable, which is not preferable. In addition, if the energization is stopped after the applied amount exceeds 80% in the first stage or the energization is stopped before reaching the applied amount of 125% in the second stage, the reduction reaction of the negative electrode unformed active material is interrupted. Therefore, it is not preferable. Furthermore, even if the energization is stopped after the applied amount exceeds 165% in the second stage, the effect of suppressing the battery temperature is hardly observed, which is not preferable.

  If the time for stopping energization after each of the first stage and the second stage is less than 0.5 hours, the effect of suppressing the battery temperature rise is not sufficient, which is not preferable. In addition, when the time for stopping energization after each of the first stage and the second stage exceeds 1.5 hours, dilute sulfuric acid reacts with the unformed active material in the middle of formation, and the unformed activity that is difficult to be oxidized / reduced. This is not preferable because a substance is formed.

  Tables 1 to 3 show the results obtained by subjecting each of the above batteries to a charge acceptance evaluation test and measuring the amount of charge until 5 seconds after the start of charging. The amount of charged electricity was a relative evaluation with Comparative Example 1 as 100.

  From the results shown in Tables 1 to 3, all of the present examples had a charge electricity amount exceeding 100, and the charge acceptance performance was improved. In particular, the charge electricity amount of Example 40 was high, and this was because an active material having a high specific surface area was obtained while suppressing an increase in battery temperature.

  As described above, by the method for producing a lead storage battery according to the present invention, a battery having excellent charge acceptance performance can be obtained.

1. Battery case, 2. Lid, 3. Terminal, 4. Injection port

Claims (1)

In a battery formation in which dilute sulfuric acid is injected into a lead-acid battery including a positive electrode plate containing an unformed positive electrode active material and a negative electrode plate containing an unformed negative electrode active material, and direct current is passed, A time zone for stopping energization is set in each of the first stage in which the amount of electric charge is between 40 and 80% and the second stage in which the amount of electric charge is between 125 and 165%, and the energization is stopped. time is 0.5-1.5 hours der respectively is, characterized that you energizing current in the second stage to the voltage application amount resume energization after a time period to stop exceeds 165 percent of A method for manufacturing a lead-acid battery.

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