阅读说明：本技术 铅蓄电池的电极体及使用电极体的铅蓄电池 (Electrode body for lead-acid battery and lead-acid battery using the same ) 是由 加藤英明 于 2018-10-12 设计创作，主要内容包括：本发明的目的在于,通过使用铝或其合金形成铅蓄电池的各结构部件的基材,且在其基材表面形成多层的镀层,实现铅蓄电池的轻量化、小型化及提高单位质量的能量密度。而且,为了防止在多层的镀层内产生针孔,对基材(22)表面进行平坦化处理、或形成其膜厚为10μm以上的镀钎料层、或层叠化学性质类似的第四族金属。另外,在正极电极板及负极电极板中,通过利用电解化成法在最表面的镀铅层形成活性物质层(24),提高铅蓄电池的充放电效率,并且大幅降低活性物质层(24)的脱落。(the invention aims to realize the light weight and the miniaturization of a lead storage battery and the improvement of energy density per unit mass by forming a base material of each structural component of the lead storage battery by using aluminum or an alloy thereof and forming a plurality of layers of plating layers on the surface of the base material. In order to prevent the occurrence of pinholes in the multi-layer plating layer, the surface of the base material (22) is subjected to a planarization treatment, or a solder plating layer having a film thickness of 10 μm or more is formed, or a group IV metal having similar chemical properties is laminated. In addition, in the positive electrode plate and the negative electrode plate, the active material layer (24) is formed on the lead-plated layer on the outermost surface by an electrolytic formation method, so that the charge and discharge efficiency of the lead storage battery is improved, and the falling-off of the active material layer (24) is greatly reduced.)

1. An electrode body of a lead-acid battery, which constitutes a positive electrode plate or a negative electrode plate of the lead-acid battery, comprising:

A base material composed of aluminum or an aluminum alloy,

A solder plating layer coating the substrate,

And the lead plating layer coats the solder plating layer.

2. The electrode body of a lead storage battery according to claim 1,

The thickness of the solder plating layer is more than 10 μm.

3. The electrode body of a lead storage battery according to claim 1,

A tin plating layer is formed between the base material and the solder plating layer.

4. The electrode body of a lead storage battery according to claim 3,

The tin plating layer has a film thickness of 1 μm or more.

5. The electrode body of a lead storage battery according to any one of claims 1 to 4,

The lead-plated layer has at least a first lead-plated layer covering the solder-plated layer and a second lead-plated layer covering the first lead-plated layer,

The first lead plating layer is composed of a plating film denser than the second lead plating layer.

6. The electrode body of a lead storage battery according to any one of claims 1 to 5,

And an active material layer is formed on the surface of the lead-plated layer.

7. A lead-acid battery is characterized in that,

The electrode body according to any one of claims 1 to 6 is used as a positive electrode plate and a negative electrode plate.

Technical Field

The present invention relates to an electrode assembly for a lead-acid battery and a lead-acid battery using the electrode assembly.

Background

Lead storage batteries are widely used for automobiles, industries, and the like, and are inexpensive and highly reliable as a result of years of experience. In general, in a lead-acid battery, a positive electrode plate and a negative electrode plate as a power generating element are stacked via a separator to form an electrode plate group, and the positive electrode plate and the negative electrode plate are connected by an electrode plate group bar. A positive electrode terminal and a negative electrode terminal were attached to both ends of the electrode plate assembly bar, and a battery was constructed using dilute sulfuric acid as an electrolyte. In general, in a lead storage battery called a paste type, in manufacturing a positive electrode plate and a negative electrode plate, a lead powder made of lead oxide and metallic lead, water, and a dilute sulfuric acid are mixed, or a reinforcing agent such as a fiber is mixed with these materials, and the mixture is filled into a lead alloy grid as an active material. Then, the plate is preheated, dried, cured and dried to produce an unformed paste active material type plate.

The electrode plate groups are inserted into an electrolytic cell together with sulfuric acid having a specific gravity of 1.28 to 1.30 through a chemical conversion step to form a single cell having a nominal voltage of 2.0V. In addition, in an automobile, a six-tank battery cell is connected as a battery having a nominal voltage of 12V.

In recent years, due to the increasing awareness of environmental protection, in particular, in the automobile industry that produces a large number of vehicles, in addition to the improvement in fuel efficiency through the reduction in weight of vehicles, the development of environmentally compatible vehicles that promote the reduction in exhaust gas has been actively pursued. In the process of development, lithium ion batteries have a problem of high safety and low cost. On the other hand, in lead-acid batteries, there is a great problem as to whether or not the batteries contribute to an improvement in fuel economy by achieving a reduction in weight through an improvement in durability and a reduction in the amount of lead used as a metal having a high specific gravity. In the lead-acid battery, a dust collector is prepared in the manufacturing process of the positive electrode plate and the negative electrode plate, but since fine-powdered lead powder is often used, fundamental improvement of the entire manufacturing process in a plan view is a problem in the future.

However, in a positive electrode plate and a negative electrode plate of a lead storage battery of the related art, which are represented by paste type, an active material in which a lead powder composed of fine powdery lead oxide and metallic lead is mixed is filled in a lattice made of a lead alloy and is manufactured in a state of being solidified by boiling. Therefore, the mass of the lead-acid battery has been increased, and there is a problem in durability such as the detachment of the active material due to vibration when used for a long time in the automobile industry, in addition to the problem of the working environment in the manufacturing process.

As a conventional technique for reducing the weight of a lead-acid battery, patent document 1 is known in which burrs generated in an electrode group bar are mechanically removed. Patent document 2 discloses a multipolar plate using a plate bonded with an active material held in a conductive fiber. Patent document 3 is also known in which weight reduction is performed using an electrode grid having a composite structure of a lead plate and a resin plate. Patent document 4 discloses a method of coating an active material on a carbon foam. Patent document 5 discloses an electrode plate in which an anti-corrosion layer of gold, silver, nickel, or the like is formed on a conductive substrate made of plastic or glass fiber coated with aluminum, magnesium, copper, or graphite, and a lead-plated layer is formed on the outermost layer, followed by application of an active material paste. Further, as a technique for thinning the lead-acid battery of the related art, the following non-patent documents are published. However, even when these techniques are used, they are not sufficient in terms of a large reduction in weight and thickness.

disclosure of Invention

Technical problem to be solved by the invention

However, the above-mentioned method of reducing the weight is not sufficient in terms of reducing the weight of the lead storage battery including the positive electrode terminal, the negative electrode terminal, and the electrode group strip, including the weight reduction and thickness reduction of the positive electrode plate and the negative electrode plate themselves, in view of the reduction of the weight of the lead storage battery, which is limited to the reduction of the number of parts of the electrode group strip, the use of the lead powder rolled plate, the positive electrode plate, and the like.

As a measure for reducing the weight and thickness, it is conceivable to replace the current collector grid made of a lead alloy with a base material made of aluminum or an alloy thereof having a low specific gravity and to laminate a lead-plated layer on the base material. However, there is a problem that pinholes generated when a plating process is performed on the surface of a base material or the like cannot be suppressed, and an electrolyte of dilute sulfuric acid corrodes the base material through the pinholes, and a desired discharge time cannot be obtained, and it is difficult to use the electrolyte as an electrode plate of a lead-acid battery.

In patent document 5, pinholes are formed in the lead plating layer, and in order to prevent the dilute sulfuric acid from penetrating into the substrate through the pinholes, the pinholes are closed with peanut oil or the like after the lead plating, and then the active material paste is applied. That is, in patent document 5, the generation of pinholes cannot be suppressed, the production process is complicated, and it is difficult to cope with mass production.

The present invention has been made in view of the above-described conventional drawbacks, and an object thereof is to provide an electrode assembly for a lead-acid battery and a lead-acid battery using the same, which are fundamentally pushed over the concept of the conventional lead-acid battery manufacturing method under a new idea, and which are made of aluminum or an alloy thereof having a low specific gravity to form a positive electrode plate, a negative electrode plate, and the like, and a plating layer of lead, a lead alloy, and the like is formed on the surface thereof by using a plating technique, thereby achieving weight reduction, thickness reduction, and durability improvement.

Means for solving the problems

In the present invention, in order to achieve the above object, the positive electrode plate and the negative electrode plate are made of aluminum or an alloy thereof, and lead or a lead alloy having at least a certain thickness is uniformly laminated on the surface by a plating method. Then, in order to impart the functions as a positive electrode plate or a negative electrode plate, a current is periodically reversed by dilute sulfuric acid, oxidation and reduction are repeated to form a positive electrode or a negative electrode active material on the surface of the lead-plated layer, and after sufficiently washing with water, drying and aging are performed to constitute a lead storage battery as the positive electrode plate or the negative electrode plate. In addition, the positive electrode terminal, the negative electrode terminal, and the electrode plate group bar, which are components other than the positive electrode plate and the negative electrode plate, are also manufactured in the same manner using aluminum materials, and a lead-plated layer made of at least lead or a lead alloy is laminated on the surface thereof, so that the lead-acid battery as a whole is reduced in weight without performing a chemical conversion treatment using dilute sulfuric acid.

in the present invention, a solder plating layer having a thickness of 10 μm or more is formed as a pinhole preventing layer on the surface of a base material made of aluminum or an alloy thereof, and a lead plating layer having a constant thickness is laminated on the surface of the solder plating layer. Then, the current is periodically reversed by dilute sulfuric acid, and oxidation and reduction are repeated to form a positive electrode plate or a negative electrode plate in which a positive electrode or a negative electrode active material is formed on the surface of the lead-plated layer. The positive electrode terminal, the negative electrode terminal, and the electrode plate group bar, which are components of the lead-acid battery other than the positive electrode plate and the negative electrode plate, are also made of aluminum materials, and a solder plating layer and a lead plating layer are formed on the surfaces thereof.

In the present invention, a tin plating layer made of tin or a tin-lead alloy as a group iv metal is formed as a pinhole preventing layer on the surface of a base made of aluminum or an alloy thereof, and a solder plating layer and a lead plating layer are laminated on the surface of the tin plating layer to a predetermined thickness. Then, in order to impart the functions as a positive electrode plate or a negative electrode plate, the current is periodically reversed by dilute sulfuric acid, and oxidation and reduction are repeated to form a positive electrode plate or a negative electrode plate in which a positive electrode or a negative electrode active material is formed on the surface of the lead-plated layer. The positive electrode terminal, the negative electrode terminal, and the electrode plate group bar, which are components of the lead-acid battery other than the positive electrode plate and the negative electrode plate, are also manufactured in the same manner using aluminum materials, and a tin-plated layer, a solder-plated layer, and a lead-plated layer are formed on the surfaces thereof.

Effects of the invention

As is apparent from the above description, the following effects are obtained in the present invention.

(1) The positive electrode plate, the negative electrode plate, the positive electrode terminal, the negative electrode terminal, and the electrode plate group bar are made of aluminum or an alloy thereof having a low specific gravity, and the aluminum substrate is protected by uniformly laminating a lead-plated layer made of at least lead or a lead alloy on the surface thereof, so that the weight can be reduced. Alternatively, the positive electrode plate and the negative electrode plate are plated with lead and then electrolytically converted with dilute sulfuric acid to produce a positive electrode active material or a negative electrode active material, thereby imparting charge and discharge characteristics. Further, the battery capacity is reduced with the reduction in thickness of the positive electrode plate and the negative electrode plate, and the amount of sulfuric acid having a specific gravity of 1.01 to 1.30, preferably 1.25 to 1.30 can be reduced. Therefore, the capacity of the entire lead-acid battery can be reduced, and the overall weight can be reduced. The present technology is an epoch-making method of plating a light aluminum material with lead or a lead alloy to reduce the amount of lead used in a lead storage battery, and periodically reversing the polarity in a dilute sulfuric acid solution after plating, thereby forming a positive electrode active material or a negative electrode active material on the surface, which fundamentally reverses the conventional concept.

(2) The positive electrode plate and the negative electrode plate are produced by laminating a lead-plated layer composed of at least lead or a lead alloy, which is a constituent element of an active material, on a sheet made of aluminum or an alloy thereof by using a plating technique. The lead-plated layer made of lead or a lead alloy is an electrochemically strong laminated film, and can prevent the positive electrode active material and the negative electrode active material from falling off due to vibration or the like, as compared with the conventional method in which a mixed active material is filled in a lead alloy grid and is solidified by boiling. Therefore, the durability of the positive electrode plate and the negative electrode plate can be improved. Further, the current collector lattice made of a conventional lead alloy can be replaced with aluminum or an alloy thereof having a low specific gravity, thereby achieving a reduction in weight. Further, since the lead-plated film laminated on the surface can be used as a positive electrode active material or a negative electrode active material by chemical conversion treatment, the lead powder mixture is filled in the lead alloy lattice, and the omission and the significant weight reduction can be achieved as compared with the conventional method.

(3) In the plating step and apparatus, in addition to the recovery of the plating solution caused by the natural falling in the recovery tank after the plating, the recovery solution by the spray cleaning in the next step is concentrated and returned to the recovery tank to be concentrated again. This can alleviate dilution by entrainment of washing water from the preceding step, and can recycle the lead compound, thereby achieving resource saving.

(4) A solder plating layer for preventing the occurrence of pinholes is formed on the surface of a base material made of aluminum or an aluminum alloy. Further, by forming the solder plating layer to have a film thickness of at least 10 μm, the recessed portions such as scratches and scratches formed on the surface of the substrate are appropriately buried in the solder plating layer, thereby preventing pinholes from being formed in the lead plating layer. As a result, the diluted sulfuric acid in the active material producing step and the diluted sulfuric acid in the electrolyte used in the lead-acid battery prevent the base material from being etched through the pinholes, thereby achieving weight reduction and thickness reduction of the positive electrode plate and the negative electrode plate and improving the energy density per unit mass of the lead-acid battery.

(5) A tin-plated layer made of tin or a tin-lead alloy of a group IV metal for preventing the occurrence of pinholes is formed on the surface of a base material made of aluminum or an aluminum alloy. Further, the tin-plated layer is a film excellent in covering properties (embedding properties), and by setting the film thickness as the tin-plated layer to 1 μm or more, concave portions such as scratches and scratches formed on the surface of the base material are appropriately embedded by the tin-plated layer, and pinholes are prevented from being formed in the lead-plated layer. As a result, the diluted sulfuric acid in the step of forming the active material layer and the diluted sulfuric acid in the electrolyte used in the lead-acid battery prevent the base material from being etched through the pinholes, thereby achieving weight reduction and thickness reduction of the positive electrode plate and the negative electrode plate and improving the energy density per unit mass of the lead-acid battery.

(6) The lead plating layer formed on the surface of the base material is formed by laminating at least 2 plating layers, wherein the lower lead plating layer is a dense plating layer, and the upper lead plating layer is a rough plating layer. With this laminated structure of the lead-plated layer, the adhesion and corrosion resistance of the plating layer can be improved by the dense lead-plated layer in the lower layer, and the surface area of the active material layer can be increased and the charge/discharge characteristics can be improved by the rough lead-plated layer in the upper layer.

Drawings

Fig. 1 is a perspective view illustrating an electrode plate manufactured by laminating a lead-plated layer on a thin plate manufactured from aluminum or an alloy material thereof according to a first embodiment of the present invention;

Fig. 2 is a cross-sectional view illustrating a lead-plated layer laminated on a thin plate made of aluminum or an alloy material thereof according to a first embodiment of the present invention;

FIG. 3 is a view for explaining the steps from the lead plating or lead alloy plating of the first embodiment of the present invention to the generation of active materials by dilute sulfuric acid electrolysis;

FIG. 4 is a perspective view illustrating a plate electrode for forming an electrode made of aluminum or an alloy material thereof according to a first embodiment of the present invention;

FIG. 5 is a substitute photograph of a drawing showing a 200 times magnified lead laminate plating surface without pinholes of the first embodiment of the present invention;

FIG. 6 is a photograph showing the surface of a positive electrode produced by anodizing a lead-plated lead in dilute sulfuric acid according to the first embodiment of the present invention enlarged by 200 times;

FIG. 7 is a photograph showing the surface of a negative electrode produced by cathodic electrolysis in dilute sulfuric acid after lead plating according to the first embodiment of the present invention, magnified by 200 times;

Fig. 8 is a graph showing the change in voltage and time during discharge of a single cell formed by alternately combining six negative electrodes with five positive electrodes of the first embodiment of the present invention covered with separators;

fig. 9 is a photograph showing an alternative drawing, which is an enlarged 200-fold view of a surface of a general lead used as a comparative example of the first embodiment of the present invention;

FIG. 10 is a photograph showing a positive electrode surface of a Strong series battery SXG40B19, made by Nippon Kogyo electric Co., Ltd., enlarged by 200 times;

FIG. 11 is a substitute photograph showing the cathode electrode surface of Strong series battery SGX40B19 manufactured by New Kilo electric corporation enlarged by 200 times, which is used as a comparative example of the first embodiment of the present invention;

FIG. 12 is a substitute photograph for drawings of an electrode grid before lead paste filling with a lead-antimony alloy of the prior art used as a comparative example of the first embodiment of the present invention;

Fig. 13 is a perspective view (a) and a sectional view (B) illustrating an electrode body of a lead-acid battery according to a second embodiment of the present invention;

Fig. 14 is a diagram for explaining a discharge test of a lead-acid battery using an electrode body of the lead-acid battery according to the second embodiment of the present invention;

Fig. 15 is a perspective view (a) and a sectional view (B) illustrating an electrode body of a lead-acid battery according to a third embodiment of the present invention;

Fig. 16 is a diagram for explaining a discharge test of a lead-acid battery using the electrode body of the lead-acid battery according to the third embodiment of the present invention.

Detailed Description

the process of the first embodiment of the present invention will be described below, but the method of plating is not limited to the process of the present invention as long as it does not exceed the gist of the present invention. In the electrode plate 11 shown in fig. 1 and 2, reference numeral 1 denotes a lead plating layer having a coarse composition, reference numeral 2 denotes a lead plating layer having a dense composition, reference numeral 3 denotes a lead alloy plating layer having a dense composition, reference numeral 4 denotes a thin plate made of aluminum or an alloy thereof, reference numeral 5 denotes a lead alloy plating layer having a dense composition, reference numeral 6 denotes a lead plating layer having a dense composition, and reference numeral 7 denotes a lead plating layer having a coarse composition. In fig. 3, reference numeral 4 denotes a thin plate made of aluminum or an alloy thereof, reference numeral 3 denotes a dense lead alloy plating layer, reference numeral 2 denotes a dense lead plating layer, reference numeral 1 denotes a rough lead plating layer for increasing the surface area, reference numeral 8 denotes a positive electrode active material generation layer by anodic electrolysis of dilute sulfuric acid, and reference numeral 9 denotes a negative electrode active material generation layer by cathodic electrolysis of dilute sulfuric acid. The dense plating layer in the present embodiment is a plating layer having a plating crystal grain size of 50nm or more and less than 5 μm, preferably 1 μm or less, and the rough plating layer is a plating layer having a plating crystal grain size of 5 μm or more and less than 50 μm.

In the following description, pure aluminum of type a1050 or a1100, or aluminum alloys of type a5052, a5058, a6061, and a7075, available from japan light metal co.

(step 1)

the aluminum plate of fig. 4 was used to produce the electrode plate by the process of fig. 3, and the inner surface portion of the plating layer was a plating layer made of lead or a lead alloy having a dense composition, thereby achieving improvement in adhesion and corrosion resistance. The outer surface of the plating layer is a plating layer made of lead or a lead alloy having a rough surface area to improve charge and discharge characteristics,

(step 2)

In general, since the surface of aluminum is covered with a strong oxide film and a plating layer having good adhesion cannot be formed, the adhesion of the plating layer is improved by applying an appropriate primer treatment to the surface of aluminum before forming the plating layer made of lead or a lead alloy. As the surface treatment, a method such as an anodic oxidation treatment, an electroless nickel plating treatment, or a tin replacement plating treatment can be selected. In this step, the electroless nickel plating treatment is applied to activate the plated surface, thereby improving the adhesion of the lead-plated layer made of lead or a lead alloy.

(step 3)

the substrate-treated aluminum plate is subjected to any one of a silicon fluoride bath, a perfluoro bath, an organic acid bath, or a plurality of baths combining them. This time, a plurality of perfluoro baths of different concentrations are used, a plating bath containing 0.1 to 5g/L of an organic additive such as gelatin or peptone is used for improving uniform electrodeposition, lead or a lead alloy having a purity of 99.99% is used as an anode, uniform stirring is performed at a current density of 0.5 to 20A/dm2, shaking is added thereto, and energization is performed for 60 to 150 minutes, thereby laminating a lead plating layer having no pinholes on an aluminum plate. The thickness of the lead-plated layer composed of at least lead or a lead alloy to be laminated can be set to 200 μm or more by changing the concentration, the energization time, the temperature, the current density, and the current waveform, but the thickness of the lead-plated layer is set to 30 to 200 μm together with the positive electrode plate and the negative electrode plate in consideration of the uniformity of the surface and the increase in the mass. The positive electrode terminal, the negative electrode terminal, and the electrode group bar were also plated to the same thickness.

Here, the lead-plated layer made of lead is a plated layer containing lead with a purity of 99.99% or more in the metal composition thereof, and the lead-plated layer made of a lead alloy is a plated layer containing lead with a purity of 95% or more in the metal composition thereof, preferably a plated layer containing lead with a purity of 97% or more, more preferably a plated layer containing lead with a maximum purity of 99%, and the same applies to the following description.

(step 4)

At least in the lead-plated layer in which lead or a lead alloy is laminated, the final plated surface is a rough lead-plated film so as to increase the surface area, and the charge/discharge characteristics of the positive electrode active material and the negative electrode active material produced by electrolytic formation of dilute sulfuric acid are improved. As a method for chemical conversion treatment for producing a positive electrode active material and a negative electrode active material after plating, a lead plate or an insoluble electrode is continuously fed with dilute sulfuric acid having a specific gravity of 1.01 to 1.30 at a current density of 0.1 to 10A/dm 2. Then, the current is reversed every 6 to 12 hours, and the anode is finally turned off in the positive electrode plate, thereby depositing a dark brown positive electrode active material on the surface of the lead-plated layer. In the negative electrode plate, a gray negative electrode active material is deposited on the surface of the lead-plated layer by the same method so as to finally become a cathode. The positive electrode plate and the negative electrode plate having the active material formed thereon are washed with running water and dried with hot air, and then left to stand naturally for 24 hours or more to be aged as a positive electrode plate and a negative electrode plate.

(step 5)

The positive electrode terminal, the negative electrode terminal, and the electrode plate assembly strip were not subjected to chemical conversion treatment for plating in the same manner as the negative electrode plate in order to maintain corrosion resistance to corrosion by dilute sulfuric acid mist.

(step 6)

Five positive electrode plates on which positive electrode active materials were formed were covered with each separator, and six negative electrode plates on which negative electrode active materials were formed were alternately stacked, and a positive electrode terminal and a negative electrode terminal were attached to the stack to produce a single cell. After dilute sulfuric acid with a specific gravity of 1.01-1.30 is injected into the single cell, the single cell is placed until heat generation stops, and then the single cell is charged at a constant voltage of 2.2-2.7V for more than 24 hours to prepare a single cell with a nominal voltage of 2V.

(step 7)

As shown in fig. 8, after completion of the charging, a 2.5V, 0.5A bulb was connected to the single cell to light the bulb, and a discharge test was performed.