JPH0754714B2 - Thin lead acid battery and manufacturing method thereof - Google Patents

Description

TECHNICAL FIELD The present invention relates to a lead acid battery and a manufacturing method thereof, and more particularly to a thin lead acid battery having a high capacity and a long life and a manufacturing method thereof.

[Prior Art] Conventional lead-acid batteries generally use a grid body filled with an active material paste as a positive electrode plate and a negative electrode plate.
The lattice body functions as a holder for the active material and also serves as a current collector. Such a lattice body is usually manufactured by casting, and an alloy containing lead as a main component is used in place of pure lead as a forming material for the purpose of improving mechanical strength.

With the spread of small devices such as portable devices in recent years, such lead-acid batteries are required to be thin.

As a conventional thin lead-acid battery, generally, the positive electrode plate and the negative electrode plate as described above are arranged in the battery case such that their main surfaces face each other with a separator interposed therebetween, and the battery case is filled with an electrolyte. What you have done is known. In such an electrode stack type thin lead-acid battery, since the respective members such as the positive electrode plate, the separator and the negative electrode plate are laminated in the thickness direction of the storage battery, the total thickness of the battery is the sum of the thicknesses of the respective members. There was a limit even if the thickness of each member was reduced and the battery as a whole was made thinner.

Japanese Patent Application Laid-Open No. 1-132064 discloses an improved thin lead-acid battery by the present applicant. This thin lead-acid battery is of an electrode parallel type in which a comb-shaped positive electrode plate and a negative electrode plate are arranged on the same plane. For example, as shown in FIG. A positive electrode plate made of a comb-shaped positive electrode current collector 2 and a positive electrode active material 3 and a negative electrode plate made of a negative electrode current collector 4 and a negative electrode active material 5 having substantially the same shape as the positive electrode current collector 2 are provided. The space between the end faces of the positive electrode plate and the negative electrode plate is filled with the electrolyte 6 containing sulfuric acid. The other battery case substrate 7 seals the entire battery to form a thin lead acid battery.

In the thin lead-acid battery having such a configuration, the positive electrode plate, the negative electrode plate, and the electrolyte between the both electrode plates are arranged on the same plane of the case substrate 1, so that the electrodes, the electrolyte, and the like are attached to the thickness of the battery. It is possible to make the battery thinner without impairing its life, as compared with a lead-acid battery of the electrode stacking type stacked in the direction.

Next, a method of manufacturing the conventional electrode parallel type thin lead-acid battery shown in FIG. 1 will be described with reference to FIGS. 2 (a), (b) and (c).

First, as shown in FIG. 2 (a), a comb-shaped positive electrode current collector 2 and negative electrode current collector 4 are formed on the main surface of the case substrate 1 at predetermined intervals. And fix them with an adhesive or the like. Next, a negative electrode mask 11 having a comb-shaped opening 10 having the same shape as the planar shape of the negative electrode current collector 4 is covered on the main surface of the case substrate 1. Then
After placing the negative electrode active material paste 12 on the negative electrode mask 11,
The plate 13 is moved in the direction of arrow A, for example, and the negative electrode active material paste 12 is applied onto the negative electrode current collector 4 through the opening 10 of the negative electrode mask 11 and printed.

Next, after removing the negative electrode mask 11, the positive electrode current collector 5 is formed on the main surface of the case substrate 1 as shown in FIG.
The positive electrode mask 15 having the comb-shaped opening 14 having the same shape as the planar shape of the above can be covered. Then, the above-mentioned negative electrode active material paste 12
In the same manner as the coating of the positive electrode active material paste 16, the positive electrode active material paste 16 is placed on the positive electrode mask 15, and then the plate 17 is moved, for example, in the direction of arrow A so that the positive electrode active material paste 16 passes through the opening 14 of the positive electrode mask 15 Print on the current collector 5 for printing.

Next, after removing the positive electrode mask 15, the printed positive and negative electrode active materials are subjected to an aging treatment and a chemical conversion treatment, washed with water and dried to form a positive electrode plate and a negative electrode plate, respectively. Next, as shown in FIG. 2 (c), the electrolyte 6 is injected into the space between the positive and negative electrode plates using a dropper 18 or the like. After that, the case substrate 7 is covered on the case substrate 1 and the peripheral portions of the case substrates 1 and 7 are sealed to obtain a thin lead acid battery.

However, the parallel electrode type thin lead-acid battery thus obtained does not have a large capacity as compared with the conventional lead-acid battery, so the positive and negative electrode active materials are made thicker to reduce the thickness and extend the service life. Efforts have been made to increase battery capacity without compromising battery power.

[Problems to be Solved by the Invention] However, in order to increase the battery capacity in this way, when a comb-shaped current collector for positive and negative electrodes is coated with a thicker active material than ever, the width of the current collector is reduced. Since the amount of active material is larger than
Adhesion between the current collector and the active material is insufficient, which causes local or full dropout failure of the active material. In particular,
Such defective removal of the active material frequently occurs during the chemical conversion treatment, and there is a drawback that the production yield is significantly reduced.

In addition, when such a thin lead-acid battery is actually operated as a finished product, the active material is locally peeled from the current collector and the life characteristics are deteriorated, or the active material is locally dropped. And there are often failures such as short circuit between electrodes,
There was a problem that greatly impaired reliability.

Therefore, for the purpose of preventing the above-mentioned peeling / falling failure of the active material, a treatment method of preliminarily blasting the surface of the current collector to increase the adhesive force with the active material was used. However,
This measure is also for the active material formed thicker than before,
It has not been possible to obtain a sufficient effect on the occurrence of peeling / falling failure. On the other hand, as a method of preventing the active material from peeling off, the width of the current collector is made wider than the conventional width,
Although there is a method of increasing the capacity by increasing the amount of active material, there is a drawback that the flat area of the thin lead storage battery becomes large, which is against the demand for downsizing of the device.

An object of the present invention is to provide a thin lead acid battery having a high capacity and a long life, which can prevent the active material from peeling off from the current collector even when the active material is applied thickly, and a manufacturing method thereof. It is in.

[Means for Solving the Problems] In order to achieve such an object, the thin storage battery of the present invention is composed of a lead or lead alloy current collector and an active material adhered to the current collector surface. In the thin lead-acid battery having the electrode plate, the current collector surface has a plurality of protrusions.

Further, the thin lead-acid battery of the present invention comprises a film-shaped first case substrate, a lead or lead alloy current collector fixed on the surface of the first case substrate, and a positive electrode current collector. A positive electrode plate composed of a positive electrode active material adhered to the surface of the electric body, and made of lead or lead alloy fixed on the surface of the film-shaped second case substrate so as to face the positive electrode plate. A negative electrode plate composed of a negative electrode current collector and a negative electrode active material in close contact with the surface of the negative electrode current collector, and an electrolyte filled in a space between the positive electrode plate and the negative electrode plate. In a thin lead-acid battery in which peripheral portions of the case substrates are joined to each other, an epoxy resin layer is formed on a surface of the current collector on the case substrate side, and the epoxy resin layer is formed on the epoxy resin layer. Chlorinated polypropylene layer containing maleic anhydride skeleton or maleic anhydride At least one layer of a mixed composition layer of a chlorinated polypropylene containing a skeleton and diglycidyl ether is formed, and a plurality of protrusions are provided on the surface of each current collector on the active material side. Characterize.

Further, the thin lead-acid battery of the present invention is a film-shaped first case substrate, and a comb-shaped lead or lead alloy positive electrode for positive electrodes which is fixed in combination with each other on the surface of the first case substrate. A current collector and a negative electrode current collector, a positive electrode plate and a negative electrode plate composed of the positive electrode active material and the negative electrode active material, which are in close contact with the surfaces of the positive electrode current collector and the negative electrode current collector, and the positive electrode plate And a film-shaped second case substrate fixed on the surface of the negative electrode plate, and an electrolyte filled in the space between the positive electrode plate and the negative electrode plate, and the respective peripheral edges of the both case substrates. In a thin lead-acid battery in which the parts are joined to each other, an epoxy resin layer is formed on the surface of each current collector on the case substrate side, and chlorine containing a maleic anhydride skeleton is formed on the epoxy resin layer. Polypropylene layer or maleic anhydride At least one layer of a mixed composition layer of chlorinated polypropylene and diglycidyl ether containing a case is formed, and a plurality of protrusions are provided on the surface of the active material side of each current collector. Characterize.

Furthermore, the method for manufacturing a thin lead acid battery of the present invention comprises a step of forming a plurality of protrusions on one surface of a plate material made of lead or a lead alloy to manufacture a positive electrode current collector and a negative electrode current collector, respectively.
A step of forming an active material layer by adhering an active material to the surface of each current collector on which the protrusion is formed, and forming an epoxy resin layer on the surface opposite to the surface of the current collector on which the protrusion is formed. ,
A step of forming at least one layer of a chlorinated polypropylene layer containing a maleic anhydride skeleton or a mixed composition layer of a chlorinated polypropylene containing a maleic anhydride skeleton and diglycidyl ether on the epoxy resin layer; A step of fixing each of the current collectors to a different case substrate through at least one of the epoxy resin layer and the chlorinated polypropylene layer containing the maleic anhydride skeleton or the mixed composition layer; And a step of joining the active material layers of the current collectors to each other with an electrolyte interposed therebetween, and then joining the peripheral portions of the case substrates to each other.

Furthermore, the method for manufacturing a thin lead storage battery of the present invention comprises a step of forming a plurality of protrusions on one surface of a plate material made of lead or lead alloy to manufacture a positive electrode current collector and a negative electrode current collector, respectively, A step of forming an active material layer by closely adhering an active material to the surface of the current collector on which the projection is formed, and forming an epoxy resin layer on the surface opposite to the surface of the current collector on which the projection is formed. A step of forming at least one layer of a chlorinated polypropylene layer containing a maleic anhydride skeleton or a mixed composition layer of a chlorinated polypropylene containing a maleic anhydride skeleton and diglycidyl ether on the epoxy resin layer, and The two current collectors are separated from each other through the epoxy resin layer and at least one layer of the chlorinated polypropylene layer containing the maleic anhydride skeleton or the mixed composition layer. A step of fixing the first case substrate to the first case substrate so as to be separated from the first case substrate; a step of filling a space between the current collectors with an electrolyte; and a step of fixing the first case substrate through the both current collectors and the electrolyte. After facing the two case substrates, the peripheral portions of the both case substrates are joined to each other.

[Operation] In the present invention, since the binding force between the current collector and the active material can be improved by the plurality of protrusions provided on the current collector surface, the active material is surely peeled off or dropped from the current collector surface. Can be prevented. It is also possible to prevent the falling defect of the active material, which frequently occurs during the production of the conventional thin lead acid battery, particularly during the chemical conversion treatment, and improve the production yield. In addition, it is possible to prevent local peeling and dropping of the active material even during operation of the thin lead acid battery, improve the life characteristics, and prevent short circuit between electrodes. Furthermore, since the binding force between the current collector and the active material is improved, the amount of the active material can be increased and the capacity can be increased.

Further, in the present invention, an epoxy resin layer having high adhesive strength on the surface of the current collector on the side of the case substrate, and a chlorinated polypropylene layer or maleic anhydride containing a maleic anhydride skeleton chemically bonded to the epoxy resin layer. Mixed composition of chlorinated polypropylene containing acid skeleton and diglycidyl ether (hereinafter abbreviated as MA-containing chlorinated polypropylene)
Since the adhesive layer including at least one of the layers is provided, the adhesive strength between the current collector and the case substrate can be increased.
If the case substrate is made of polypropylene resin, sufficient adhesive strength can be obtained at a temperature below the melting point of polypropylene, so it is possible to prevent displacement of the electrodes and prevent thermal deformation of the case substrate. Is.

Furthermore, since the epoxy resin has excellent sulfuric acid resistance,
Prevents electrolyte from entering the case substrate side of the current collector, suppresses oxidative corrosion of the current collector, and shortens battery life even if the thickness of the electrode is thin, aiming for longer life You can

[Examples] Hereinafter, the details of the present invention will be described by examples with reference to the drawings.

(Embodiment 1) An embodiment of a method of manufacturing an electrode laminated type thin lead-acid battery of the present invention will be described with reference to FIGS. 3 (a) to 3 (d).

First, a plate material 20 made of lead or a lead alloy having a thickness of 0.2 mm is provided between a hole forming plate 21 and a pressing plate 22 made of stainless steel having a plurality of cylindrical concave holes as shown in FIG. 3 (a). After being sandwiched, the plate member 20 is pressed / stretched into the holes of the hole forming plate 21 by the pressure stretching means to form a plurality of columnar projections 23 on the surface of the plate member 20 as shown in FIG. 3 (b). did. Here the cylindrical protrusion 23
Is formed by pressing / stretching the plate member 20 into a cylindrical shaving portion formed on the surface of the cylindrical concave hole forming plate 21.

Next, an epoxy adhesive layer 24 is applied and cured on the surface of the plate member 20 opposite to the surface on which the projections 23 are formed, and a chlorinated polypropylene resin layer 25 is further applied on the epoxy adhesive layer 24 and applied at room temperature. After drying, flat plate-shaped positive electrode current collector 26 and negative electrode current collector 27 were formed by a method such as punching. Subsequently, the positive electrode current collector produced as shown in FIG. 3 (c).
26 was fixed to a sheet-shaped case substrate 28, and the negative electrode current collector 27 was fixed to a case substrate 29 having the same shape as the case substrate 28 by thermocompression bonding.

Next, as shown in FIG. 3D, the positive electrode active material 30 and the negative electrode active material 31 were printed at a maximum thickness of 1 mm on the projection forming surfaces of the positive electrode current collector 26 and the negative electrode current collector 27, respectively. Next, both active materials 30 and 31 were subjected to usual aging and chemical conversion treatments, and then washed with water and dried. Further, an electrolyte 32 is placed in the gap between both active materials 30 and 31, and finally, a third
As shown in FIG. 3D, the case substrate 28 and the other case substrate 29 having the function of the lid are superposed on each other, and
The circumference of 28 and 29 is sealed by thermocompression bonding, and the thickness is 3m.
A thin lead-acid battery of m or less was completed.

(Embodiment 2) An embodiment of a method for manufacturing an electrode parallel type thin lead-acid battery of the present invention will be described with reference to FIGS. 2 (a) to (c) and FIG.

Similar to the first embodiment, the cylindrical concave hole forming plate 21 is used, and a plurality of cylindrical projections 23 are formed on the surface of the plate material 20 made of lead or lead alloy.
4 is formed from a plate material made of lead or a lead alloy having protrusions 23 by a method such as punching after forming an epoxy resin, applying and curing epoxy adhesive on the back surface, and applying and drying chlorinated polypropylene. A comb-shaped positive electrode current collector 40 and negative electrode current collector 41 were formed as shown in FIG.

Next, as shown in FIG. 4, the positive electrode current collector 40 and the negative electrode current collector 41 were separated from each other and fixed by thermocompression bonding on the same plane of the sheet-shaped case substrate 1. Thereafter, as shown in FIGS. 2 (a) and 2 (b), a positive electrode collector is prepared by a method similar to the method for manufacturing a thin lead storage battery disclosed in Japanese Patent Application Laid-Open No. 1-132064 shown in FIG. Current collector 40 and collector for negative electrode
The positive electrode active material 12 and the negative electrode active material 16 were printed on 41 with a maximum thickness of 2 mm. Further, the positive and negative electrode active materials were subjected to usual aging treatment and chemical conversion treatment, washed with water and dried to form a positive electrode plate and a negative electrode plate, respectively. Next, as shown in FIG. 2 (c), the electrolyte 6 is injected into the space between the positive and negative electrode plates, and finally, the other case substrate 7 having the same shape and material having the function of a lid is overlapped, and both cases are The peripheral portions of the substrates 1 and 7 were sealed by thermocompression bonding to complete a thin lead acid battery having a thickness of 3 mm or less.

(Example 3) In substantially the same manner as in Example 1, a plate material 20 made of flat lead or lead alloy having a thickness of 0.2 mm was formed into a plurality of striped concave grooves as shown in Fig. 5 (a). It is sandwiched between the groove forming plate 43 made of stainless steel and the pressing plate 22 and is pressed / stretched by the pressing / stretching means, and the surface of the plate material 20 made of lead or lead alloy is shown in FIG.
And a striped protrusion 44 as shown in (c). Here, the striped protrusions 44 are formed by pressing and stretching the plate member 20 on the striped shavings formed on the surface of the striped groove forming plate 43. After that, as in Examples 1 and 2, after applying and curing epoxy adhesive and chlorinated polypropylene and drying on the surface opposite to the surface on which the projections are formed, a flat plate is formed by a method such as punching. Then, a comb-shaped positive electrode current collector and negative electrode current collector were formed, and thereafter, electrode stack type and electrode parallel type thin lead acid batteries were produced by the same method as in the first and second examples. As the pressurizing / stretching means used in each of the above examples,
For example, a press molding machine, a desktop press machine, a stretching machine and the like are suitable.

(Example 4) A plurality of lead or lead alloy projections prepared in advance were fixed to an arbitrary position on the surface of a plate-shaped or comb-shaped current collector for positive and negative electrodes with an adhesive. In the same manner as in Examples 1 and 2, the electrode lead type and the electrode parallel type thin lead acid batteries were assembled.

The shape of the protrusion takes into consideration the adhesiveness between the battery capacity and the active material,
In the shape of a stake with a pointed or rectangular cross section as shown in Fig. 6,
The height of the protrusions was about half the thickness of the active material layer to be printed. In Examples 1 and 2, since the thickness of the active material layer was about 2 mm, the thickness of the protrusion was set to about 1 mm. As the adhesive, an epoxy adhesive having excellent sulfuric acid resistance or a conductive epoxy adhesive containing lead or lead alloy particles is desirable.

The protrusions in this case may be formed by melting lead or lead alloy on the surface of each current collector with a soldering iron or the like.

The shape of the protrusions may be spherical, needle-like, lattice-like, polygonal columnar, or conical in addition to FIG. 6, and the material of the protrusions is the same as that of the current collector that does not adversely affect the battery reaction. It is preferably lead or a lead alloy.

In addition, the method of manufacturing the protrusion basically does not change depending on the shape of the protrusion.

In each of the above examples, the chlorinated polypropylene resin layer
Instead of 25, the MA-containing chlorinated polypropylene resin layer described above can be used.

Further, as the case substrate, the back surface of the case substrate may be a polypropylene layer satisfying thermocompression bonding property, strength,
In consideration of the water vapor barrier property, it is preferable to have a multi-layer laminate film structure using polypropylene, polyethylene terephthalate, polyvinylidene chloride, Al or the like and having a thickness of about 0.1 mm.

In addition, each of the above-described embodiments exemplifies the technical idea of the present invention, and does not limit the gist and application range of the present invention. Further, although a flat plate-like plate material is used as the current collector in each of the above-described embodiments, a foil-like plate may be used.

(Comparative Example 1) Based on a conventional method for manufacturing a thin lead-acid battery, a flat plate-shaped lead or lead alloy plate material having a thickness of 0.2 mm was used to form a flat plate-shaped or comb-shaped positive electrode without forming protrusions on the surface of the plate material. The current collector for the negative electrode and the current collector for the negative electrode were punched out, and thereafter, Example 1 and Example 2 were performed.
In the same manner as above, an electrode stack type and an electrode parallel type thin lead acid battery were assembled.

(Characteristic Confirmation Test) The characteristics of thin lead-acid batteries according to Examples 1 to 4 and Comparative Example 1 described above were examined.

(1) In the thin lead acid batteries according to Examples 1 to 4, there was no defect of the active material falling off from the current collector during the aging / chemical formation process of the manufacturing process, but in the case of Comparative Example 1, it was localized. Dropout was observed.

(2) When a charge / discharge test was performed on Examples 1 to 4 and Comparative Example 1, in all cases of Examples 1 to 4, 100
The initial capacity was maintained at 50% or more after the cycle, but in the case of Comparative Example 1, the capacity decreased to 50% or less of the initial capacity after 30 cycles.

The charging / discharging conditions are 2.45V constant voltage charging, current limit 100mA,
It was charged for 8 hours, rested for 1 hour after charging, discharge current was 200 mA, and discharge end voltage was 75V.

(3) The adhesive strength between the current collector and the case substrate in Examples 1 to 4 was practically sufficient, and the current collector did not drop off from the case substrate.

As described above, according to the thin lead acid battery of the present invention,
Since the plurality of protrusions formed on the surface of the current collector can improve the binding force between the current collector and the active material, the active material can be reliably prevented from peeling off from the surface of the current collector. It is also possible to prevent the falling defect of the active material, which frequently occurs during the production of the conventional thin lead acid battery, particularly during the chemical conversion treatment, and improve the production yield. In addition, it is possible to prevent local peeling and dropping of the active material even during operation of the thin lead acid battery, improve the life characteristics, and prevent short circuit between electrodes. Furthermore, since the binding force between the current collector and the active material is improved, the amount of the active material can be increased and the capacity can be increased.

Further, according to the present invention, the adhesive strength between the current collector and the case substrate can be increased by the adhesive layer composed of the epoxy resin layer and the MA-containing chlorinated polypropylene layer. If the case substrate is made of polypropylene resin, sufficient adhesive strength can be obtained at a temperature below the melting point of polypropylene, so it is possible to prevent displacement of the electrodes and prevent thermal deformation of the case substrate. Is.

Furthermore, since the epoxy resin has excellent sulfuric acid resistance,
Prevents the invasion of the electrolyte into the case substrate side of the current collector, suppresses oxidative corrosion of the current collector, and does not shorten the battery life even if the thickness of the electrode is thin, aiming for longer life You can

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view showing a structure of a thin lead acid battery, and FIGS. 2 (a) to (c) are exploded perspective views showing a manufacturing process of a conventional thin lead acid battery. 3 (a) to 3 (d) are schematic configuration diagrams for explaining an example of a method for manufacturing an electrode laminated type thin lead acid battery of the present invention, and FIG. 4 is an electrode parallel type thin lead acid battery of the present invention. 5 is a perspective view showing an example of the structure of the current collector used in FIG. 5, FIGS. FIG. 6 is a cross-sectional view showing another example of the structure of the current collector used in the thin lead acid battery of the present invention. 1 ... Case substrate, 2 ... Positive electrode current collector, 3 ... Positive electrode active material, 4 ... Negative electrode current collector, 5 ... Negative electrode active material, 6 ...
Electrolyte, 7 ... Case substrate, 10 ... Opening, 11 ... Anode mask, 12 ... Anode active material paste, 13 ... Plate, 14 ...
Opening part, 15 ... Positive electrode mask, 16 ... Positive electrode active material paste, 17 ... Plate, 18 ... Dropper, 20 ... Plate material, 21 ... Hole forming plate, 22 ... Press plate, 23 ... Projection, 24 ... Epoxy adhesive layer, 25 ... Chlorinated polypropylene resin layer, 26 ...
… Positive electrode plate, 27 …… Negative electrode plate, 28 …… Sheet-shaped case substrate,
29 …… Sheet case substrate, 30 …… Cathode active material, 31 ……
Negative electrode active material, 32 ... Electrolyte, 40 ... Positive electrode current collector, 41 ...
… Negative electrode current collector, 43 …… Groove forming plate, 44 …… Protrusion, 45 ……
Protrusion.

Front page continuation (72) Inventor Minoru Takahashi 1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corp. Telephone Co., Ltd. (56) Reference JP-A-62-103989 (JP, A) JP-A-1-132064 (JP, A) Actual Kaihei 2-84265 (JP, U)

Claims (4)

[Claims] 1. A film-shaped first case substrate, a positive electrode current collector made of lead or lead alloy fixed on the surface of the first case substrate, and a surface of the positive electrode current collector. A positive electrode plate composed of a positive electrode active material adhered to a negative electrode, and a lead or lead alloy negative electrode current collector fixed on the surface of a film-shaped second case substrate so as to face the positive electrode plate. And a negative electrode plate composed of a negative electrode active material adhered to the surface of the negative electrode current collector, and an electrolyte filled in a space between the positive electrode plate and the negative electrode plate, the both case substrates In a thin lead-acid battery in which the respective peripheral portions are joined to each other, an epoxy resin layer is formed on the case substrate side surface of each current collector, and a maleic anhydride skeleton is formed on the epoxy resin layer. Contains a chlorinated polypropylene layer containing or a maleic anhydride skeleton At least one layer of a mixed composition layer of chlorinated polypropylene and diglycidyl ether is formed, and a plurality of protrusions are provided on the surface of the current collector on the active material side. Thin lead acid battery. 2. A film-shaped first case substrate, and a comb-shaped lead or lead alloy positive electrode current collector and negative electrode, which are fixed in combination with each other on the surface of the first case substrate. A current collector, a positive electrode plate and a negative electrode plate composed of a positive electrode active material and a negative electrode active material, which are in close contact with the surfaces of the positive electrode current collector and the negative electrode current collector, and on the surfaces of the positive electrode plate and the negative electrode plate. A film-shaped second case substrate fixed to, and an electrolyte filled in the space between the positive electrode plate and the negative electrode plate, the respective peripheral portions of both case substrates are bonded to each other. In the thin lead-acid battery, the epoxy resin layer is formed on the surface of the current collector on the side of the case substrate, and the chlorinated polypropylene layer or maleic anhydride layer containing a maleic anhydride skeleton is formed on the epoxy resin layer. Salt containing an acid skeleton Characterized in that at least one layer of a mixed composition layer of modified polypropylene and diglycidyl ether is formed, and a plurality of protrusions are provided on the surface of each current collector on the active material side. Lead acid battery. 3. A step of forming a plurality of protrusions on one surface of a plate material made of lead or a lead alloy to manufacture a positive electrode current collector and a negative electrode current collector, respectively, and forming the protrusions of each current collector. A step of forming an active material layer by closely adhering the active material to the surface of the current collector, and forming an epoxy resin layer on the surface opposite to the projection forming surface of each of the current collectors, and then forming maleic anhydride on the epoxy resin layer. A step of forming at least one layer of a chlorinated polypropylene layer containing an acid skeleton or a mixed composition layer of a chlorinated polypropylene containing a maleic anhydride skeleton and diglycidyl ether; A step of fixing to a different case substrate through a resin layer and at least one layer of a chlorinated polypropylene layer containing the maleic anhydride skeleton or the mixed composition layer, A method of manufacturing a thin lead-acid battery, comprising the steps of facing the active material layers of the current collectors with an electrolyte in between, and then joining the peripheral portions of the case substrates to each other. 4. A step of forming a plurality of protrusions on one surface of a plate material made of lead or a lead alloy to manufacture a positive electrode current collector and a negative electrode current collector, respectively, and forming the protrusions of each current collector. A step of forming an active material layer by closely adhering the active material to the surface of the current collector, and forming an epoxy resin layer on the surface opposite to the projection forming surface of each of the current collectors, and then forming maleic anhydride on the epoxy resin layer. A step of forming at least one layer of a chlorinated polypropylene layer containing an acid skeleton or a mixed composition layer of a chlorinated polypropylene containing a maleic anhydride skeleton and diglycidyl ether; The first case is so arranged that the current collectors are separated from each other through at least one of the resin layer and the chlorinated polypropylene layer containing the maleic anhydride skeleton or the mixed composition layer. A step of adhering to the substrate; a step of filling a space between the current collectors with an electrolyte; and a step of facing the first case substrate to a second case substrate through the current collectors and the electrolyte. And a step of joining the peripheral portions of the both case substrates to each other, the method of manufacturing a thin lead storage battery.