JP2005353559A - Lead acid battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To add an organic polymer to an electrolyte solution automatically over a long time for making the activity of a negative electrode active material of a lead acid battery maintained for a long time. <P>SOLUTION: The lead acid battery comprises a container provided in the electrolyte solution having dilute sulfuric acid as the main component, the container having a gap communicating with the electrolyte solution. The container is filled with the organic polymer that dissolves in the electrolyte solution and is capable of raising a hydrogen overvoltage of the negative electrode, when charging is performed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a lead-acid battery that can withstand long-term use as compared with conventional lead-acid batteries.

  Conventionally, as a method for recovering the characteristics of a lead-acid battery that has deteriorated due to long-term use, the present inventors have incorporated a specific organic polymer, such as polyvinyl alcohol or polyacrylic, in the electrolyte, which has the effect of increasing the hydrogen overvoltage of the negative electrode. A method for recovering the capacity and internal resistance of a lead-acid battery by adding an acid ester, lignin or the like has been invented (for example, JP 2001-313064 A). However, these organic polymers added to the electrolyte solution gradually oxidize and disappear at the positive electrode when charging and discharging are repeated, and the effect gradually decreases, so it was necessary to add these organic polymers every year. . Further, it has been impossible to add an organic polymer in a sealed lead-acid battery that does not require replenishment of an electrolyte.

  The present invention automatically replenishes the organic polymer into the electrolyte solution little by little for a long period of time, thereby replenishing the organic polymer that has been oxidized and disappeared at the positive electrode and maintaining the characteristics of the lead-acid battery for an extremely long period of time. It is what.

  The present invention relates to an electrolyte containing dilute sulfuric acid as a main component or an electrolyte containing 0.01 to 0.2 wt% of an organic polymer containing sulfuric acid as a main component and capable of increasing the hydrogen overvoltage of a negative electrode during charging. And a container having a gap communicating with the electrolytic solution, and the container is filled with an organic polymer (hereinafter referred to as “organic polymer”) that dissolves in the electrolytic solution and can increase the hydrogen overvoltage of the negative electrode during charging. Lead acid battery, and an electrolyte containing 0.01 to 0.2% by weight of an organic polymer containing dilute sulfuric acid as a main component or an organic polymer containing sulfuric acid as a main component and capable of increasing the hydrogen overvoltage of the negative electrode during charging. A lead storage battery in which the organic polymer solid is brought into contact with the electrolyte, which has a very low solubility rate in the electrolyte and can increase the hydrogen overvoltage of the negative electrode during charging when dissolved in the electrolyte. It is.

  Preferably, the container having a gap communicating with the electrolytic solution is a lead storage battery composed of any one of glass fiber, polyethylene resin, polypropylene resin, and fluororesin, and the organic polymer is polyvinyl alcohol, polyacrylic acid, A lead acid battery comprising at least one of the group consisting of polyacrylic acid ester and lignin, wherein the organic polymer solid is polyvinyl alcohol, and the organic polymer solid is present in the negative electrode or the negative electrode surface It is the lead acid battery which is the structure which adhered to.

  The organic polymer used in the present invention acts on the surface of the negative electrode during charge / discharge in a lead storage battery using dilute sulfuric acid as an electrolyte, and has the effect of remarkably reducing the lead particles that are the active material of the negative electrode. The lead particles produced by the electrochemical reaction in the presence of this organic polymer are extremely active compared to the conventional lead particles produced by mechanical methods such as the Shimadzu ball mill method and the molten lead method. In addition, fine lead particles as a new substance are synthesized.

  The organic polymer used in the present invention is preferably present in an amount of 0.001 to 0.5% in the electrolytic solution. Even if a large amount of the organic polymer is added at a time, it foams during charging and overflows from the battery case, Therefore, it is not preferable because it is oxidized in 1 to 2 years. In order to maintain the effect of the organic polymer for a long period of time, it is desirable to add the organic polymer to the electrolyte automatically in small amounts so as to supplement the amount oxidized at the positive electrode.

  As a means for this, the inventors filled these organic polymers into a container having a gap communicating with the electrolyte of the lead storage battery, and when the container was immersed in the electrolyte, Once absorbed and gelled, most of it stays in the container, and part of the gel gradually diffuses into the electrolyte of the lead-acid battery through a gap communicating with the electrolyte of the container, leading to a long-term lead-acid battery. It has been found that the concentration of the organic polymer in the electrolyte solution can be maintained at a required value. Further, if the organic polymer solid substance that can increase the hydrogen overvoltage of the negative electrode during charging is present in the battery in the state of being in contact with the electrolyte when dissolved in the electrolyte, the solubility rate in the electrolyte is extremely slow. The organic polymer concentration in the electrolyte of the lead-acid battery can be increased over a long period of time by replenishing the organic polymer that gradually dissolves into the electrolyte and replenishes the organic polymer that is decomposed by the oxidation reaction at the positive electrode during charging. It has been found that the required value can be maintained. By these methods, when a container filled with an organic polymer is incorporated into the battery at the time of manufacturing the lead acid battery, or when an organic polymer solid substance having a very low solubility rate is present in the battery in contact with the electrolyte, A long life of 10 years or more can be expected as a calculated value from the diffusion rate or dissolution rate of the organic polymer.

  As a container having a gap communicating with the electrolyte solution of the lead storage battery used in the present invention, a container of any shape that can withstand the dilute sulfuric acid of the electrolyte solution can be used, a bag made of glass fiber, a polyethylene resin A bag or tube made of polypropylene resin or fluororesin can be preferably used. The size of the void provided in the container may be appropriately selected according to the degree of polymerization of the organic polymer, the concentration of the organic polymer in the electrolytic solution, the usage environment of the lead battery, and the like.

  Further, in the present invention, in order to further promote the refinement of the lead particles of the negative electrode in addition to the organic polymer in the container having a gap communicating with the electrolyte of the lead storage battery, the particle diameter is 0.1 to 5 micrometers. Fine particles such as carbon, lignin, and barium sulfate, and fine particles such as sodium sulfate, indium sulfate, and tin sulfate may be added.

  For example, as shown in FIG. 1, a flat bag 1 of cloth woven with glass fiber is filled with organic polymer powder 2 as a form in which a container having a gap communicating with the electrolyte of a lead storage battery is filled. Can be sandwiched between the negative electrode 4 and the separator 5 of the sealed battery 3. The bag 1 may be disposed on a part of the surface of the negative electrode 4 as shown in FIG. In some sealed batteries, the electrolyte exists only inside the porous separator and the electrode, and hardly exists between the battery case and the electrode. A method of sandwiching a container containing an organic polymer between the negative electrode and the separator is an extremely effective method for adding an organic polymer. In the case of a battery having a liquid stopper hole 6 in the upper part of the battery, as shown in FIG. 3, an organic polymer powder is filled in a polypropylene resin container 7 having a plurality of holes having a diameter of 0.1 to 0.01 mm. May be inserted into the upper space in the battery case 8 through the liquid stopper hole 6.

  Examples of organic polymer solids that have a very slow solubility rate in the electrolyte and can increase the hydrogen overvoltage of the negative electrode during charging when dissolved in the electrolyte include polyvinyl alcohol molded into plates, granules, and fibers. For example, Ecomaty AX manufactured by Nippon Synthetic Chemical Industry Co., Ltd. can be suitably used. By sticking these organic polymer solids on the negative electrode surface or using them in a state where they are interposed in the negative electrode active material, the organic polymer gradually elutes into the electrolyte, and the concentration falls within a substantially constant range. As a result, the effect of making the lead particles, which are the active material of the negative electrode, extremely fine can be maintained for a long period of time and the battery life can be extended.

  Cross section   Container layout on the negative electrode surface   Cross section

Explanation of symbols

1: Fabric bag 1 woven with glass fiber
2: Organic polymer powder 3: Sealed battery 4: Negative electrode 5: Separator 6: Liquid stopper hole 7: Polypropylene resin container 8: Battery case

Claims (6)

  In an electrolyte containing dilute sulfuric acid as a main component or in an electrolyte containing 0.01 to 0.2% by weight of an organic polymer containing sulfuric acid as a main component and capable of increasing the hydrogen overvoltage of the negative electrode during charging A lead-acid battery comprising: a container having a gap communicating with the container; and the container is filled with an organic polymer that can be dissolved in the electrolyte and increase a hydrogen overvoltage of the negative electrode during charging.   2. The lead acid battery according to claim 1, wherein the container having a gap communicating with the electrolytic solution is made of any one of glass fiber, polyethylene resin, polypropylene resin, and fluororesin.   3. The lead acid battery according to claim 1, wherein the organic polymer includes at least one of the group consisting of polyvinyl alcohol, polyacrylic acid, polyacrylic acid ester, and lignin.   In an electrolyte containing dilute sulfuric acid as a main component or in an electrolyte containing 0.01 to 0.2% by weight of an organic polymer containing sulfuric acid as a main component and capable of increasing the hydrogen overvoltage of the negative electrode during charging A lead-acid battery characterized in that it has a very slow solubility rate in contact with an organic polymer solid that can increase the hydrogen overvoltage of the negative electrode during charging when dissolved in the electrolyte.   5. The lead acid battery according to claim 4, wherein the organic polymer solid is polyvinyl alcohol.   6. The lead-acid battery according to claim 4 or 5, wherein the organic polymer solid is present in the negative electrode or attached to the negative electrode surface.

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