JPH04188568A - Thin-form lead-acid battery and manufacture thereof - Google Patents

Abstract

PURPOSE:To prevent segregation and slipping-off of active substance from a current collector and provide a resultant battery with a high capacity and long life by furnishing a plurality of projections on the surface of the current collector made of Pb or Pb alloy. CONSTITUTION:Epoxy type adhesive agent layer 24 is applied to that surface of a plate material 20 which is situated opposite the surface where projections 23 are formed, followed by hardening process, and thereover a layer 25 of chlorinated polypropylene resin is applied. The resultant is left for drying at room temp., and a current collector 26 for pos. electrode and a one 27 for neg. electrode are accomplished in the form of a flat plate. A pos. electrode active substance 30 and neg. electrode active substance 31 are printed on each projection-equipped surface to a max. thickness of 1mm, which is subjected to maturing and chemical formation process, and an electrolyte 32 is arranged in the gap between these to active substances 30, 31. Thereby the bond of the current collector and active substance is enhanced by a plurality of projections provided on the surface of current collector, which prevents segregation and slipping-off of the active substance from the surface of current collector certainly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a lead-acid battery and a manufacturing method thereof, and more particularly to a high-capacity, long-life thin lead-acid battery and a manufacturing method thereof.

[Prior Art 1] A conventional lead-acid battery generally uses a lattice body filled with an active material paste as a positive electrode plate and a negative electrode plate.

The lattice 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 whose main component is lead instead of pure lead is used as the 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 made thinner.

Conventional thin lead-acid batteries generally have a positive electrode plate and a negative electrode plate as described above arranged in a battery case so that their main surfaces face each other with a separator in between, and an electrolyte in an N battery case. It is known that it is filled with In such thin lead-acid batteries of laminated electrode type, each of the positive electrode plate, separator, negative electrode plate, etc. is laminated in the thickness direction of the battery, so the overall thickness of the battery is equal to the thickness of each member. This is comparable to the sum of the thicknesses, so even if the thickness of each member was made thinner and the overall thickness of the battery could be made thinner, there was a limit.

Japanese Unexamined Patent Publication No. 1-132064 discloses an improved thin lead-acid battery by the present applicant. This thin lead-acid battery is of a parallel electrode 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. 1,
On the surface of one film-like case substrate, there is a positive electrode plate consisting of a substantially comb-shaped positive electrode current collector 2 and a positive electrode active material 3, and a negative electrode current collector 4 having approximately the same shape as the positive electrode current collector 2; A negative electrode plate made of a negative electrode active material 5 is provided, and an electrolytic plate 6 containing sulfuric acid is provided in the space between each end face of the positive electrode plate and the negative electrode plate.
is filled. The entire battery is sealed by the other film-like case substrate 7 to form a thin lead-acid battery.

In a thin lead-acid battery with such a configuration, the positive electrode plate, the negative electrode plate, and the electrolyte between these plates are arranged on the same plane of the case substrate 1, so that the electrodes, electrolyte, etc. are aligned in the thickness direction of the battery. Compared to lead-acid batteries with stacked electrodes, they can be made thinner without sacrificing service life.

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

First, as shown in FIG. 2(a), a comb-shaped positive electrode current collector 2 and a negative electrode current collector 4 are formed on the main surface of the case substrate l with a predetermined interval between the two current collectors. Combine them so that they fit together and fix them with adhesive, etc. Next, a negative electrode mask 11 having a comb-shaped opening 10 having the same planar shape as the negative electrode current collector 4 is placed over the main surface of the case base @1. Next, after placing the negative electrode active material paste 12 on the negative electrode mask 11, the plate 13 is moved, for example, along the six directions of arrows, and the negative electrode active material base 1-12 is placed in the opening J of the negative electrode mask IJ.
It is applied to the negative electrode current collector 4■ through O and printed.

Next, after removing the negative electrode mask 11, as shown in FIG.
As shown in FIG. 2, a positive electrode mask 15 having a comb-shaped opening 14 having the same planar shape as the positive electrode current collector 5 can be placed over the main surface of the case substrate l. Next, in the same way as applying the negative electrode active material paste 12 described above, the positive electrode active material paste 16 is applied.
After placing the positive electrode mask 15 on the soil, the plate 17 is moved, for example, along the six directions of the arrows, and the positive electrode active material paste 16 is applied onto the positive electrode current collector 5 through the opening 14 of the positive electrode mask 15 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, and then washed with water and dried to form a positive electrode plate and a negative electrode plate, respectively. Next, as shown in FIG. 2(c), electrolyte 6 is injected into the space between the positive and negative electrode plates using a dropper 18 or the like. Thereafter, the case substrate 7 is placed over the case substrate 1, and the peripheral edges of both case substrates 1 and 7 are sealed to obtain a thin lead-acid battery.

However, since conventional lead-acid batteries do not have a large capacity, the thin lead-acid batteries with parallel electrodes obtained in this way are made thinner and longer by forming the positive and negative electrode active materials even thicker. Efforts are being made to increase battery capacity without compromising longevity.

[Problem to be Solved by the Invention 1] However, in order to increase the battery capacity, when a thicker active material is applied to the comb-shaped current collector for positive and negative electrodes than before, the width of the current collector becomes Because the amount of active material is larger compared to
Adhesion between the current collector and the active material is insufficient, resulting in failure of the active material to fall off locally or over the entire surface. especially,
Such defects in active material falling off occur frequently during chemical conversion treatment, which has the disadvantage of significantly lowering manufacturing yield.

In addition, when such a thin lead-acid battery is actually operated as a finished product, the active material may locally peel off from the current collector, deteriorating the life characteristics, or the active material may fall off locally. Failures such as short circuits between electrodes often occur due to
There was a problem that significantly reduced reliability.

Therefore, in order to prevent the active material from peeling off or falling off as described above, a treatment method has been used in which the surface of the current collector is subjected to a blast treatment in advance to increase the adhesion to the active material. However,
This measure also applies to active materials formed thicker than before.
It has not been possible to obtain a sufficient effect on the occurrence of peeling/falling failures. On the other hand, as a method to prevent this active material from peeling off or falling off, the width of the current collector is made wider than the conventional width.
There is a method of increasing the capacity by increasing the amount of active material, but this has the disadvantage that the flat area of the thin lead-acid battery becomes large, which goes against the demand for more compact devices.

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

[Means for Solving the Problems 1] In order to achieve such an object, the thin lead-acid battery of the present invention is composed of a current collector made of lead or a lead alloy and an active material closely adhered to the surface of the current collector. In the thin lead-acid battery having a flat electrode plate, the current collector surface has a plurality of protrusions.

Further, the thin lead-acid battery of the present invention includes a film-like 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 positive electrode current collector made of lead or lead alloy. A positive electrode plate composed of a positive electrode active material adhered to the surface of the electric body, and a lead or lead alloy made of lead or lead alloy fixed to the surface of a film-like second case substrate so as to face the positive electrode plate. A negative electrode plate comprising a negative electrode current collector, a negative electrode active material closely 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. , in the thin lead-acid battery in which the respective peripheral edges of both the case substrates are joined to each other, an epoxy resin layer is formed on the case substrate side surface of each of the current collectors, and an epoxy resin layer is formed on the epoxy resin layer. At least one layer of a chlorinated polypropylene layer containing a maleic anhydride skeleton or a mixed composition layer of chlorinated polypropylene containing a maleic anhydride skeleton and diglycidyl ether is formed, and the activation of each of the current collectors is formed. A feature is that a plurality of protrusions are provided on the material side surface.

Furthermore, the thin lead-acid battery of the present invention includes a film-like first case substrate, and a comb-shaped positive electrode made of lead or lead alloy that is combined and fixed to the surface of the first case substrate. A positive electrode plate and a negative electrode plate each comprising a current collector, a negative electrode current collector, a positive electrode active material and a negative electrode active material that are in close contact with the surfaces of the positive electrode current collector and negative electrode current collector, and the positive electrode plate. and a second case substrate in the form of a film 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 peripheral edge of each of the case substrates. In a thin lead-acid battery in which parts are joined to each other, an epoxy resin layer is formed on the case substrate side surface of each current collector, and chlorine containing a maleic anhydride skeleton is formed on the epoxy resin layer. At least one layer of a chlorinated polypropylene layer or a mixed composition layer of chlorinated polypropylene containing a maleic anhydride skeleton and diglycidyl ether is formed, and a plurality of protrusions are formed on the active material side surface of each current collector. It is characterized by being provided with.

Furthermore, the method for manufacturing a thin lead-acid battery of the present invention includes forming a plurality of protrusions on one surface of a plate made of lead or lead alloy to manufacture a current collector for a positive electrode and a current collector for a negative electrode, respectively;
A step of closely adhering an active material to the protrusion-formed surface of each of the current collectors to form an active material layer, and forming an epoxy resin layer on the opposite surface of the protrusion-formed surface of each of the current collectors. ,
forming at least one layer of a chlorinated polypropylene layer containing a maleic anhydride skeleton or a mixed composition layer of chlorinated polypropylene and diglycidyl ether containing a maleic anhydride skeleton on the epoxy resin layer; Each current collector is fixed to a first different case substrate through the epoxy resin layer and at least one of the chlorinated polypropylene layer containing a maleic anhydride skeleton or the mixed composition layer. The process of
The method is characterized in that it includes a step of joining the peripheral edges of both the case substrates to each other after the active material layers of both the current collectors are opposed to each other with an electrolyte interposed therebetween.

Furthermore, the method for manufacturing a thin lead-acid battery of the present invention includes a step of forming a plurality of protrusions on one surface of a plate made of lead or lead alloy to manufacture a positive electrode current collector and a negative electrode current collector, respectively; A step of closely adhering an active material to the surface on which the protrusions are formed of the current collector to form an active material layer, and forming an epoxy resin layer on the surface opposite to the surface on which the protrusions are formed of each of the current collectors. 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; Both current collectors are separated from each other through the epoxy resin layer, at least one of the chlorinated polypropylene layer containing a maleic anhydride skeleton, or the mixed composition layer, so that the image aggregates are separated from each other. a step of fixing the first case substrate to the case substrate; a step of filling the space between the two current collectors with an electrolyte; and a step of making the first case substrate face the second case substrate via both the current collectors and the electrolyte. The method is characterized in that it further includes a step of joining the peripheral edge portions of both the case substrates to each other.

[Function] In the present invention, the bonding force between the current collector and the active material can be improved by the plurality of protrusions provided on the current collector surface, so that peeling and falling off of the active material from the current collector surface can be prevented. This can be reliably prevented. It is also possible to improve the manufacturing yield by preventing the failure of the active material to fall off, which frequently occurs during the manufacturing of conventional thin lead-acid batteries, especially during chemical conversion treatment. Further, even during operation of a thin lead-acid battery, it is possible to prevent local peeling and falling off of the active material, improve life characteristics, and prevent short circuit between electrodes. Furthermore, since the bonding force between the current collector and the active material is improved, the amount of the two active materials can be increased, and a high capacity can be achieved.

In addition, in the present invention, an epoxy resin layer with high adhesive strength is provided on the surface of the current collector on the case substrate side, and a chlorinated polypropylene layer containing a maleic anhydride skeleton or a maleic anhydride layer is chemically bonded to the epoxy resin layer. Since an adhesive layer consisting of at least one layer of a mixed composition of chlorinated polypropylene containing an acid skeleton and diglycidyl ether (hereinafter abbreviated as MA-containing chlorinated polypropylene),
The adhesive strength between the current collector and the case substrate can be increased. When the case substrate is made of polypropylene resin, sufficient adhesive strength can be obtained at a temperature below the melting point of polypropylene, making it possible to prevent electrode displacement and thermal deformation of the case substrate. It is.

Furthermore, since epoxy resin has excellent sulfuric acid resistance,
It prevents electrolyte from entering the case substrate side of the current collector, suppresses oxidation corrosion of the current collector, and prevents shortening of battery life even if the electrode thickness becomes thinner. be able to.

[Example 1] Hereinafter, details of the present invention will be explained by an example with reference to the drawings.

(Example 1) An example of the method for manufacturing an electrode stacked 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 lead alloy with a thickness of 0.2 mm is placed between a hole forming plate 21 made of stainless steel having a plurality of cylindrical concave holes and a pressing plate 22, as shown in FIG. 3(a). After sandwiching the plate material 20 between the holes, the plate material 20 is formed into the hole-formed plate 2 by means of pressure stretching
3 (b) on the surface of the plate material 20.
A plurality of cylindrical protrusions 23 were formed as shown in FIG. Here, the cylindrical protrusion 23 is formed by pressing and stretching the plate material 20 into a cylindrical cut-out 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 opposite side of the plate material 20 to the side on which the projections 23 are formed, and then a chlorinated polypropylene resin layer 25 is overlaid and applied on the epoxy adhesive layer 24 at room temperature. After drying, a flat plate-shaped positive electrode current collector 26 and negative electrode current collector 27 are formed by punching or other methods.
was formed. Subsequently, the positive electrode current collector 26 prepared as shown in FIG. 3(C) was placed on a sheet-like case substrate 28, and the negative electrode current collector 27 was placed on a case substrate 2 having the same shape as the case substrate 28.
9 by thermocompression bonding.

Next, as shown in FIG. 3(d), a positive electrode active material 3 is placed on each protrusion-forming surface of the positive electrode current collector 26 and the negative electrode current collector 27.
0 and negative electrode active material 31 were printed with a maximum thickness of 1 mm. Next, these active materials 30 and 31 were subjected to normal aging and chemical conversion treatment, and then washed with water and dried.

Furthermore, an electrolyte 32 is placed in the gap between both active materials 30 and 31, and finally, as shown in FIG. 3(d), the case substrate 28 and the other case substrate 29 having a lid function are overlapped, The peripheral portions of both case substrates 28 and 29 were sealed by thermocompression bonding to complete a thin lead-acid battery having a thickness of 3 mm or less.

(Example 2) An example of the method for manufacturing a thin lead-acid battery of parallel electrode type according to the present invention will be described with reference to FIGS. 2(a) to fc) and FIG. 4.

As in Example 1, using the cylindrical concave hole forming plate 21,
A plurality of cylindrical projections 23 are formed on the surface of a plate material 20 made of lead or lead alloy, and an epoxy adhesive is applied to the back surface of the projections 23.
After hardening treatment and coating and drying treatment of chlorinated polypropylene, a comb-shaped positive electrode current collector 40 as shown in FIG. A negative electrode current collector 41 was formed.

Next, as shown in FIG. 4, the positive electrode current collector 40 and the negative electrode current collector 41 were fixed to each other on the same plane of the sheet-like case substrate 1 by thermocompression bonding while being separated from each other. Then the second
The manufacturing method shown in FIG. 2 (
As shown in a) and (b), the positive electrode active material 12 and the negative electrode active material 16 were printed on the positive electrode current collector 40 and the negative electrode current collector 41 to a maximum thickness of 211 Ilm. Further, the positive and negative electrode active materials were subjected to normal aging treatment and chemical conversion treatment, and then washed with water and dried to form a positive electrode plate and a negative electrode plate, respectively. Next, as shown in FIG. 2(C), electrolyte 6 is injected into the space between the positive and negative electrode plates, and finally, the other case substrate 7 of the same shape and material, which functions as a lid, is placed on top of the other, and both cases are closed. The peripheral portions of the substrates 18 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 almost the same manner as in Example 1, a flat lead or lead alloy plate 2o with a thickness of 0.2 mm was formed into a plurality of striped concave shapes as shown in FIG. 5(a). It is sandwiched between a stainless steel groove forming plate 43 having grooves and a holding plate 22, and is pressed and stretched by a pressure stretching means to form the surface of the lead or lead alloy plate 20 as shown in FIG. 5(b) and Striped projections 44 as shown in (c)
form. Here, the striped protrusions 44 are formed in striped grooves formed on the surface of the striped concave groove forming plate 43 on the plate material 2o.
It is formed by applying pressure and stretching. after that,
As in Examples 1 and 2, after coating and curing the epoxy adhesive and coating and drying the chlorinated polypropylene on the surface opposite to the surface on which the protrusions are formed, a flat plate and a comb are formed by punching or other methods. A current collector for a positive electrode and a current collector for a negative electrode were formed in the following shapes, and thereafter thin lead-acid batteries of an electrode stack type and an electrode parallel type were manufactured in the same manner as in the first and second examples. As the pressurizing/stretching means used in each of the above-mentioned Examples, for example, a press molding machine, a bench press machine, a stretching machine, etc. are suitable.

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

The shape of the protrusion is determined by considering battery capacity and adhesion with the active material.
Shaped into a pointed or rectangular pile shape as shown in Figure 6,
The height of the protrusions was approximately half the thickness of the active material layer to be printed. In Examples 1 and 2, the thickness of the active material layer was approximately 2 mm, so the thickness of the protrusion was approximately 1 mm. The adhesive 2 is preferably an epoxy adhesive having excellent sulfuric acid resistance or a conductive epoxy adhesive containing lead or lead alloy particles.

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

In addition to the shape shown in Figure 6, the shape of the protrusion may be spherical, needle-like, grid-like, polygonal columnar, or conical. Preferably it is lead or a lead alloy.

Furthermore, the method of manufacturing the protrusions does not fundamentally change at all depending on the shape of the protrusions.

In each of the two examples, the above-mentioned HA-containing chlorinated polypropylene resin layer can be used in place of the chlorinated polypropylene resin layer 25.

Furthermore, as for the case substrate, it is sufficient that the back side of the case substrate is a polypropylene layer that satisfies thermocompression bondability, strength,
In consideration of water vapor barrier properties, it is preferable to have a multilayer laminate film structure of about 0.1 mm thick using polypropylene, polyethylene terephthalate, polyvinylidene chloride, etc.

Furthermore, the above-mentioned embodiments exemplarily illustrate the technical idea of the present invention, and do not limit the gist and scope of the present invention. Further, in each of the above-described embodiments, a flat plate material was used as the current collector, but a foil-like material may also be used.

(Comparative Example 1) Based on the conventional manufacturing method of thin lead-acid batteries, a plate made of lead or lead alloy with a thickness of 0.2mm is made into a flat plate or comb shape without forming any protrusions on the plate surface. The positive electrode current collector and the negative electrode current collector were punched out, and then the electrode lamination type and electrode parallel type thin lead-acid batteries were assembled in the same manner as in Example 1 and Example 2.

(Test on Characteristics) The characteristics of the 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 of Examples 1 to 4, there was no failure of the active material to fall off from the current collector during the aging and chemical formation process of the manufacturing process, but in the case of Comparative Example 1, there was no failure of the active material to fall off from the current collector. Falling off was observed.

(2) When a charge/discharge test was conducted on Examples 1 to 4 and Comparative Example 1, in the cases of Examples 1 to 4, 50% or more of the initial capacity was maintained even after 100 cycles. On the other hand, in the case of Comparative Example 1, the capacity decreased to 50% or less of the initial capacity after 30 cycles.

The charging and discharging conditions are 2.45V constant voltage charging, current limit 1
00 mA, charging for 8 hours, charging connection for 1 hour, discharge current of 200 mA, and discharge end voltage of 1.75 V.

(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 come off from the case substrate.

[Effects of the Invention j As explained above, according to the thin lead-acid battery of the present invention,
Since the plurality of protrusions formed on the current collector surface can improve the bonding force between the current collector and the active material, it is possible to reliably prevent the active material from peeling off or falling off from the current collector surface. It is also possible to improve the manufacturing yield by preventing the failure of the active material to fall off, which frequently occurs during the manufacturing of conventional thin lead-acid batteries, especially during chemical conversion treatment. Further, even during operation of a thin lead-acid battery, it is possible to prevent local peeling and falling off of the active material, improve life characteristics, and prevent short circuit between electrodes.

Furthermore, since the bonding 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 consisting of the epoxy resin layer and the MA-containing chlorinated polypropylene layer. When the case substrate is made of polypropylene resin, sufficient adhesive strength can be obtained at a temperature below the melting point of polypropylene, making it possible to prevent electrode displacement and thermal deformation of the case substrate. It is.

Furthermore, since epoxy resin has excellent sulfuric acid resistance,
Prevents electrolyte from entering the case substrate side of the current collector, suppresses oxidation corrosion of the current collector, and extends battery life without shortening battery life even if the electrode thickness becomes thinner. I can do it.

[Brief explanation of the drawing]

Figure 1 is an exploded perspective view showing the structure of a thin lead-acid battery, Figures 2 (a) to (c) are exploded perspective views showing the manufacturing process of a conventional thin lead acid battery, and Figures 3 (a) to ( d) is a schematic configuration diagram for explaining an example of the manufacturing method of the electrode stacked type thin lead acid battery of the present invention, and Figure 4 is a diagram showing the current collector used in the electrode parallel type thin lead acid battery of the present invention. A perspective view showing an example of the structure, FIGS. 5(a) to 5(c) are schematic configuration diagrams for explaining another example of the method for manufacturing a thin lead-acid battery of the present invention, and FIG. FIG. 3 is a cross-sectional view showing another example of the structure of a current collector used in a lead-acid battery. DESCRIPTION OF SYMBOLS 1... Case substrate, 2... Current collector for positive electrode, 3... Positive electrode active material, 4... Current collector for negative electrode, 5... Negative electrode active material, 6... Electrolyte, 7 ... Case substrate, 10... Opening, 11... Negative electrode mask, 12... Negative electrode active material paste, 13... Plate, 14... Opening, 15... Positive electrode mask. 16... Positive electrode active material paste, 17... Plate, 18... Dropper, 20... Plate material, 21... Hole forming plate, 22... Holding plate, 23... Protrusion, 24... ... Epoxy adhesive layer, 25... Chlorinated polypropylene resin layer, 26... Positive electrode plate, 27... Negative electrode plate, 28... Sheet-like case substrate, 29... Sheet-like case substrate, 30... Positive electrode active material, 31... Negative electrode active material, 32... Electrolyte, 40... Current collector for positive electrode, 41... Current collector for negative electrode, 43... Groove forming plate, 44...Protrusion, 45...Protrusion. Patent applicant Nippon Telegraph and Telephone Corporation

Claims (1)

[Claims] 1) A thin lead-acid battery having an electrode plate composed of a current collector made of lead or a lead alloy and an active material closely adhered to the current collector surface, the current collector surface having a plurality of A thin lead-acid battery characterized by having protrusions. 2) A first case substrate in the form of a film, a positive electrode current collector made of lead or lead alloy fixed on the surface of the first case substrate, and a positive electrode current collector fixed on the surface of the positive electrode current collector. a positive electrode plate made of a positive electrode active material; a negative electrode current collector made of lead or lead alloy fixed on the surface of a film-like second case substrate so as to face the positive electrode plate; and the negative electrode. a negative electrode plate made of a negative electrode active material that is in close contact with a surface of a 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 whose peripheral parts 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 contained on the epoxy resin layer. At least one layer of a chlorinated polypropylene layer or a mixed composition layer of chlorinated polypropylene containing a maleic anhydride skeleton and diglycidyl ether is formed, and a plurality of layers are formed on the active material side of each current collector. A thin lead-acid battery characterized by being provided with protrusions. 3) A film-like first case substrate, and a comb-shaped lead or lead alloy positive electrode current collector and negative electrode current collector that are combined and fixed to each other on the surface of the first case substrate. and a positive electrode plate and a negative electrode plate composed of a positive electrode active material and a negative electrode active material that are in close contact with the surfaces of the positive electrode current collector and the negative electrode current collector, and a positive electrode plate and a negative electrode plate that are fixed on the surfaces of the positive electrode plate and the negative electrode plate. a thin film-like second case substrate; and an electrolyte filled in a space between the positive electrode plate and the negative electrode plate, and the peripheral edges of both the case substrates are joined to each other. In a lead-acid battery, an epoxy resin layer is formed on the case substrate side surface of each current collector, and a chlorinated polypropylene layer containing a maleic anhydride skeleton or a maleic anhydride skeleton is formed on the epoxy resin layer. At least one layer of a mixed composition of chlorinated polypropylene and diglycidyl ether contained therein is formed, and a plurality of protrusions are provided on the active material side surface of each current collector. A thin lead-acid battery. 4) A step of manufacturing a positive electrode current collector and a negative electrode current collector by forming a plurality of protrusions on one surface of a lead or lead alloy plate material, and forming a plurality of protrusions on one surface of a plate material made of lead or a lead alloy, and forming a plurality of protrusions on the surface of each of the current collectors on which the protrusions are formed. After forming active material layers by closely adhering the active materials, and forming an epoxy resin layer on the surface opposite to the protrusion forming surface of each of the current collectors,
forming at least one layer of a chlorinated polypropylene layer containing a maleic anhydride skeleton or a mixed composition layer of chlorinated polypropylene containing a maleic anhydride skeleton and diglycidyl ether on the epoxy resin layer; fixing each of the current collectors to different case substrates via the epoxy resin layer and at least one of the chlorinated polypropylene layer containing the maleic anhydride skeleton or the mixed composition layer; A method for manufacturing a thin lead-acid battery, comprising the step of: arranging the active material layers of both current collectors to face each other with an electrolyte interposed therebetween, and then joining peripheral portions of both case substrates to each other. 5) A step of forming a plurality of protrusions on one surface of a plate made of lead or lead alloy to produce a positive electrode current collector and a negative electrode current collector, respectively; After forming active material layers by closely adhering the active materials, and forming an epoxy resin layer on the surface opposite to the protrusion forming surface of each of the current collectors,
forming at least one layer of a chlorinated polypropylene layer containing a maleic anhydride skeleton or a mixed composition layer of chlorinated polypropylene containing a maleic anhydride skeleton and diglycidyl ether on the epoxy resin layer; The two current collectors are separated from each other through the epoxy resin layer, at least one 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; a step of filling an electrolyte in the space between the two current collectors; and a step of fixing the first case substrate to the second case substrate via the two current collectors and the electrolyte. A method for manufacturing a thin lead-acid battery, comprising the step of: facing each other, and then joining the peripheral edges of both case substrates to each other.