JP3006283B2 - Laminated batteries - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated type dry battery,
More specifically, the present invention relates to an integrated processing of a negative electrode zinc and a conductive carbon film of the zinc-carbon bonded electrode (hereinafter, referred to as a bonded electrode), and a stacked battery using the same.

[0002]

2. Description of the Related Art In general, a stacked manganese dry battery represented by a 6F22 type has a structure shown in FIG. 6 cells 7
A wax is applied to the outer periphery where the positive electrode current collector plate 5 is stacked on the uppermost portion, and the contents covered with the PVC tube 4 are arranged on the upper and lower portions, respectively, with the terminal plate 3 and the bottom plate 9 being arranged. Temporarily tightened.

The unit cell shown in FIG. 2 is housed in a cell grommet of a PVC tube 12 with a separator 13 separating a bonding electrode 14 in which a zinc plate and a conductive carbon film are integrated and a positive electrode mixture 11.

A conventional carbon-bonded electrode for a stacked manganese dry battery has a configuration as shown in FIG. In FIG.
Reference numeral 15 denotes a conductive carbon coating, and reference numeral 16 denotes a zinc plate. As shown in FIG. 5, in the conventional bonding electrode, a flexible sheet-like conductive carbon film 20 formed by kneading a synthetic resin and a large amount of carbon powder on one surface of a zinc sheet 19 forming a negative electrode and reducing the thickness by a rolling roll. The manufacturing method of bonding was adopted. In particular, this manufacturing method is applied to one surface of the conductive carbon coating 20 to which an adhesive such as polyvinyl isobutyl alcohol is added in advance.
An organic solvent such as xylene for dissolving the conductive carbon film was applied and pressed against the zinc sheet 19, and then punched into a predetermined shape by a press.

[0005]

In the structure of such a conventional coupling electrode, the adhesion between the conductive carbon film and the zinc plate is as follows.
It is performed only by a synthetic resin as a binder and a binder which has been melted out by applying an organic solvent such as xylene and has been added to the conductive carbon film in advance. However, at the same time, the carbon powder in the conductive carbon coating also separates from the coating and acts to increase the conductivity of the adhesive layer, but due to the release action of carbon itself and the inertness of the surface, the conductive carbon coating is It has the disadvantage that the adhesion to the zinc plate is significantly weakened. As shown in Table 1, this phenomenon is remarkable when the bonding electrode is stored for a long time, and the weak bonding between the conductive carbon coating and the zinc plate is directly reflected in the resistance of the bonding electrode. Resulting in.

[0006]

[Table 1]

[0007] In Table 1, especially in the case of the bonding electrode stored at 45 ° C, the conductive carbon coating and the zinc plate easily peeled off after storage.

On the other hand, a stacked manganese dry battery has a structure in which a plurality of the same unit cells are stacked to obtain a high voltage, but the unit cells are connected via a conductive carbon film on one surface of a coupling electrode. Needless to say, the coupling electrode itself is required to have a low resistance stably over time. Particularly in heavy load discharge performance, the resistance of the coupling electrode is greatly affected, and the coupling having the lowest possible resistance is required. Electrodes are preferred.

Therefore, the present invention is to provide a material in which the zinc plate of the bonding electrode and the conductive carbon film are firmly adhered and the adhesion is stable over time. It is an object of the present invention to provide a coupling electrode having a stable resistance.

[0010]

SUMMARY OF THE INVENTION In order to solve such problems, the present invention provides a method of bonding a zinc sheet and a conductive carbon film to a thermosetting resin-based adhesive such as an epoxy resin or a urethane resin. It is diluted with an organic solvent such as acetone together with a predetermined curing agent, applied to one surface of the conductive carbon film and adhered to a zinc sheet, and furthermore, an adhesive layer between the zinc sheet and the conductive carbon film forms an electric insulator. Preliminarily dilute the thermosetting resin-based adhesive and the curing agent in an organic solvent to increase the conductivity of the adhesive layer so that the bonding electrode occupied by the thermosetting resin-based adhesive does not have a high resistance. In this case, a certain amount of fine metal powder of an electric good conductor is added.

[0011]

According to this structure, the resistance of the coupling electrode of the present invention can be reduced by the presence of the fine metal powder of the electric conductor between the conductive carbon film and the zinc plate. In addition, since these are firmly bonded with a thermosetting resin-based adhesive, the bonding strength and resistance can be stabilized with time.

[0012]

Embodiments of the present invention will be described below with reference to the tables.

(Table 2) shows an example of the composition of the conductive carbon film used in the examples, and (Table 3) shows the adhesive liquid to be applied to the conductive carbon film shown in (Table 2) before adding the metal fine powder. Are shown below.

[0014]

[Table 2]

[0015]

[Table 3]

With respect to the conductive carbon coating of (Table 2) and the adhesive liquid of (Table 3), each of which was added with metal fine powder,
A coupling electrode was constructed based on the examples shown in (Table 4), and the change over time in the resistance was shown in (Table 5). FIG. 4 shows an enlarged sectional view of the coupling electrode according to the present invention.

In FIG. 4, reference numeral 15 denotes a conductive carbon film,
Reference numeral 6 denotes a zinc plate, and reference numeral 17 denotes an adhesive made of an epoxy resin, a curing agent, and the like, into which a fine metal powder such as a fine nickel powder 18 is added. In Table 4, the addition rate is
It is a weight ratio with respect to the adhesive liquids 1 to 3 in (Table 3). Further, as the metal fine powder used in the examples, nickel was obtained by a carbonyl method capable of obtaining a fine powder of high purity, and other metals used were obtained by electrolysis and pulverization.

[0018]

[Table 4]

[0019]

[Table 5]

As is clear from Table 5, the resistances of the coupling electrodes of Examples 2 to 11 constituted according to the present invention are all superior to those of the conventional coupling electrodes, including the change with time.
In Example 1, although strong adhesion was achieved with the epoxy resin, the resistance value was stable over time because no metal fine powder was added, but the value was extremely high. Was. More specifically, the particle diameter of the metal fine powder added to the adhesive liquid in Examples 2 to 5 is preferably less than 10 μm. If the particle diameter is larger than that, the resistance is high even if the same weight is added. Even when the metal fine powder was added and dispersed in the liquid, the metal fine powder settled remarkably, making it difficult to apply uniformly.

Further, the epoxy resin used in the present embodiment,
Good adhesion was observed for both the urethane resin adhesive and the urethane resin adhesive.

Regarding the metal fine powder to be added,
Although it was recognized that a low resistance can be realized for all of gold, silver, copper, and nickel, as shown in Comparative Examples 1 to 3, metals having a lower resistance than nickel have a higher resistance value.

The addition rate of these metal fine powders is suitably at least 10% by weight based on the total weight of the resin and the curing agent. There is a problem of an increase in cost due to an increase in the amount of used.

Further, the following 6F22 type stacked manganese dry battery was constructed using the coupling electrode constructed according to the embodiment of the present invention, immediately after the construction, and after storage at room temperature for one year, at 45 ° C.
Under the three conditions after storage for three months, constant current discharge was continuously performed at 50 mA, and the discharge time until the battery voltage reached 5.4 V is shown in (Table 6).

Dry cell A: A 6F22-type laminated dry battery comprising the conventional coupling electrodes shown in Table 5. Dry battery B ... 6 composed of the coupling electrode of Example 3 of (Table 5)
F22 type dry battery.

Dry cell C: A 6F22 type laminated dry battery comprising the coupling electrodes of Example 8 in (Table 5).

[0027]

[Table 6]

As is clear from Table 6, the laminated manganese dry battery constituted by the coupling electrode according to the embodiment of the present invention has a low resistance and is stable over time.
It was recognized that the heavy-load discharge performance was improved and the storability was also improved as compared with the conventional dry battery.

[0029]

According to the present invention, when the conductive carbon film and zinc are integrated with each other in the bonding electrode of the laminated manganese dry battery, gold, silver or the like is used for the thermosetting resin adhesive such as epoxy resin or urethane resin. By adding a relatively noble, highly conductive metal fine powder such as copper, nickel, etc. and bonding them together, it enables strong adhesion and realizes low resistance. The present invention provides an excellent bonding electrode which can stabilize the dry battery, and using these, it is possible to improve the heavy load discharge performance of the dry battery and further improve the storage stability.

In the present invention, the metal fine powder is used to increase the conductivity of the adhesive layer, but from this viewpoint, even if a carbon fine powder such as graphite or carbon black is used,
Similarly, the conductivity of the adhesive layer can be increased to provide a bonding electrode with low resistance.However, since the surface of the carbonaceous fine powder is inert and the fine powder itself has mold release properties, the conductive carbon coating and the zinc plate can be used. Has a characteristic that the adhesion of the electrode is unstable over time and the resistance of the coupling electrode gradually increases during storage.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a structural example of a stacked manganese dry battery to which the present invention is applied.

FIG. 2 is a cross-sectional view of a structural example of a unit cell constituting a stacked manganese dry battery to which the present invention is applied.

FIG. 3 is an enlarged sectional view of a conventional coupling electrode.

FIG. 4 is an enlarged sectional view of a coupling electrode according to the present invention.

FIG. 5 is a schematic view of an apparatus for manufacturing a coupling electrode according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Positive electrode mixture 13 Separator 14 Carbon-zinc bonding electrode 15 Conductive carbon film 16 Zinc plate 17 Adhesive (epoxy resin and hardener) 18 Nickel fine powder

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01M 6/46 H01M 4/06

Claims (3)

(57) [Claims] 1. A stacked battery comprising a plurality of unit cells each comprising a positive electrode mixture, a separator and a zinc-carbon binding electrode, wherein the zinc-carbon binding electrode comprises a plate-like zinc negative electrode,
A laminated dry battery in which a synthetic resin and a conductive carbon film mainly composed of carbon are integrated with an adhesive to which conductive metal fine powder is added. 2. The stacked dry battery according to claim 1, wherein the conductive metal fine powder is at least one of gold, silver, copper, and nickel having a particle size of 10 μm or less. 3. The laminated dry battery according to claim 1, wherein the amount of the conductive metal fine powder added to the adhesive is 10 to 50% by weight.