JP4794184B2 - Method for producing electrode plate for alkaline storage battery - Google Patents

Description

The present invention relates to a method for manufacturing an electrode plate for an alkaline storage battery in which blades used in a portion where an active material is present and a portion where no active material is present are changed.

In recent years, as devices have become increasingly portable and cordless, there is an increasing demand for secondary batteries that are small, lightweight, and have high energy density as these power supplies. In particular, a high-capacity and inexpensive secondary battery is demanded, and there is a strong demand for cost reduction of alkaline storage batteries represented by nickel-hydrogen storage batteries, nickel-cadmium storage batteries and the like, and improvement in market reliability.

Under such circumstances, paste type electrode plates capable of high-density filling of active materials have become mainstream as electrode plates for alkaline storage batteries capable of high density and high capacity. As the paste-type electrode plate, generally, a sponge-like porous metal substrate (hereinafter simply referred to as a foam metal substrate) or a perforated thin steel plate having three-dimensionally continuous fine pores such as foam metal and felt metal. (Hereinafter, simply referred to as a porous substrate in the present application) and the like, a plate original plate in which a paste-like kneaded material mainly composed of an active material is applied and filled into a core material is cut into a predetermined size. The electrode plate is cut by a “punching method” in which the plate is punched with a press die.

As a technique using a punching method, a core material made of three-dimensional foam metal is filled with an active material before pressing, and all the parts except for the part that becomes the core material exposed part are subjected to press work, and almost halved. A method (Patent Document 1) in which a desired shape is formed in a punching process through compression, an active material removal process, and formation of a current collector is performed.

JP 2002-343345 A

However, in the punching method as described in Patent Document 1, since the active material layer filled with the active material of the electrode plate original plate is directly cut, the life of the blade is shortened, and operations such as polishing of the blade edge or replacement of the blade edge are frequently performed. There is a problem that it is necessary for the maintenance and the maintenance is troublesome. Further, since the electrode plate original plate coated with the active material is directly cut, burrs and protrusions are easily generated on the end face and cannot be completely removed. When trying to construct a plate group by laminating with other polar plates through a separator using such a plate, the separator breaks through the return burr or protrusion on the end face of the plate, resulting in this A slight short circuit occurs between the positive electrode and the negative electrode.

Under such circumstances, it is desirable to provide a method for manufacturing an electrode plate that extends the tool life and prevents burrs and protrusions from returning to the end face of the electrode plate.

The present invention provides an electrode plate for an alkaline storage battery in which an active material layer filled with an active material in a core material and a plain part not filled with an active material are formed, and this is cut to produce an electrode plate of a predetermined shape. A portion where the active material is present at the cut portion is cut with a shear blade, and a portion where no active material is present is punched with a press blade.

The active material layer filled with the active material in the core material and the plain part not filled with the active material are formed, the active material layer is cut with a shear blade, and the plain part is pressed with a press blade, thereby extending the tool life and maintenance. The timing can be greatly improved, and the return burr and protrusion generated on the short surface of the electrode plate can be eliminated.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

The feature of the present invention is that the portion where the active material is present at the cutting portion is cut with a shear blade, and the portion where the active material is not present is punched out with a press blade, thereby extending the tool life and reducing the return burr on the short plate surface. This prevents the formation of protrusions. 1 and 2 are explanatory views of an electrode plate manufacturing apparatus used in the method of the present invention, which are a shear cutting machine and a press machine, respectively. 3 shows the shape of the electrode plate original plate cut by the cutting machine of FIG. 1, FIG. 4 shows the shape of the press blade of the press machine of FIG. 2, and FIG. 5 shows the shape of the electrode plate after pressing.

FIG. 1 is an explanatory view of a shear cutting machine for carrying out the method of the present invention. 1 is a shear cutting machine, 11 is a drive device, 12 is an upper shear blade, 13 is a lower shear blade, 14 is a base to which the lower shear blade 13 is attached, 15 is a control device for changing the speed of the drive roller, 16 Denotes a drive roller, and 17 denotes a feed roller. The paste-type electrode plate of the present invention can be applied to either a positive electrode plate or a negative electrode plate, and the following description will be made using a cadmium electrode plate that is a negative electrode plate.

Reference numeral 3 denotes an electrode plate original plate formed by forming an active material layer filled with an active material in a long core material and a plain part not filled with the active material, and an organic viscous material such as cadmium oxide active material powder or polyvinyl alcohol (PVA). Binders, nylon fibers, acrylic fibers and other reinforcing agents are kneaded together with an organic solvent such as ethylene glycol to make a paste, and this is applied to both sides of a core consisting of a conductive porous substrate plated with nickel. It is dried and wound into a roll.

A driving device 11 is installed at the upper center of the shear cutting machine 1, and a flat plate-shaped upper shear blade 12 having a sharp tip is attached to the driving device 11, and a flat plate having a blade portion at a corner so as to face it. A lower shear blade 13 is attached to the base 14. These shear blades are those in which the upper shear blade 12 descends and meshes with the lower shear blade 13 to be cut linearly. Further, the lower shear blade 13 is attached by screwing a bolt to a threaded portion (not shown) provided on the base 14, and can be exchanged. Further, a feed roller control device 15 is installed at the upper portion of the entrance of the cutting machine 1 (on the side where the electrode plate original plate is transferred). A large number of feed rollers 17 are installed under the control device 15 so as to face each other, and are transported while sandwiching the electrode plate 3 between the drive roller 16 and the feed roller 17 of the control device 15 so as to be wound into a roll. It can be cut in a state perpendicular to the shearing blade by correcting the wrinkle of the electrode plate 3 with a wrinkle and keeping it horizontal. The drive roller 16 below the feed roller control device 15 is provided opposite to the feed roller 17 below the feed roller 17 in the vicinity of the upper and lower shear blades 12 and 13, but is opposed to all the feed rollers. May be provided.

A belt conveyor 5 is disposed in front of the upper and lower shear blades 12 and 13, and a partition 6 is provided at the tip of the belt conveyor.

Using such a shear cutting machine, the electrode plate original plate 3 wound in a roll shape is unwound and the electrode plate original plate 3 is sandwiched between the feed roller control device 15 and the feed roller 16 to the upper upper and lower shear blades 12 and 13 in front. The upper shear blade 12 is lowered by the driving device 11 when it passes through the upper and lower shear blades 12 and 13 by a predetermined distance, and is engaged with the lower shear blade 13 to cut the electrode plate original plate 3 to a predetermined width. The original cutting plate 4 cut to the predetermined width falls on the front belt conveyor 5 and is conveyed. At this time, since there is a partition 6 at the tip of the belt conveyor 5, the original cutting plate 4 does not fall from the conveyor 5.

The cut original plate 4 is shown in FIG. The portions indicated by the hatched portions are formed in two rows on the left and right with an active material layer 41 in which a large number of openings in the core material are filled with the active material. The other part is a plain part 42 of the core material not filled with the active material. The central plain portion 42 is formed to be slightly wider. The cutting original plate 4 had no burrs or protrusions at the cut portion.
Then, the cutting original plate 4 is transferred to the next press machine.

FIG. 2 is an explanatory diagram of a press for carrying out the method of the present invention. Reference numeral 2 denotes a press, 21 denotes a driving device, 22 denotes a punch, and 23 denotes a die.

A driving device 21 is installed at the upper front of the press machine 2, a punch 22 formed integrally with the lower portion of the driving device 21 is attached, and a die 23 is attached below the punch 22 so as to face the punch 22. The punch 22 and the die 23 constitute a press blade. The press machine 2 obtains the electrode plate 7 having a predetermined shape as shown in FIG. 5 by the punch 22 being lowered by the driving device 21 and meshingly pressed with the die 23. FIG. 4 is a top view of the die 23, which is formed to protrude in the same shape as the predetermined shape of the electrode plate to be obtained. In this press machine, since two electrode plates are punched from one cutting original plate 4, two dies 23 are formed. Then, a punch 22 having a predetermined shape having a wide area shown by a hatched portion in FIG. 4 is lowered from above and meshes with the die 23.

Using such a press 2, the cutting original plate 4 is put on the die 23 one by one by the operator, and the punch 22 is lowered by the driving device 21 that operates when the operator presses the switch, and is attached to the lower part. The electrode plate is obtained by meshing with the formed die 23 and punching only the uncoated portion 42 of the original cutting plate 4 into a predetermined shape. The electrode plate 7 punched into a predetermined shape is taken out by the operator, and is repeatedly performed by newly placing the original cutting plate 4 on the die 23. In addition, as shown in FIG. 5, the two electrode plates 7 can be obtained by one press. Reference numeral 71 denotes an ear portion of the electrode plate 7.

Conventionally, the production of the electrode plate has been performed only by punching using only a press machine, and the wear of the press blade where the active material is applied has been severely caused, resulting in an early life of the press blade. This also caused burrs and protrusions on the cut surface of the electrode plate. In the present invention, by changing the blade between the active material layer and the plain portion, it is possible to reduce the wear of the blade and extend the replacement time, and it is possible to prevent burrs and protrusions generated in the cut surface of the electrode plate. . It should be noted that the press blade in the case of being manufactured only with a conventional press machine had to be replaced by polishing the blade edge every time punching was performed about 10,000 times. There was no need to replace it about 30,000 times. Conventionally, a pressing margin is required when pressing, but according to the method of the present invention, the pressing margin is not required, and the yield is improved by 5% compared with the punching of the conventional press only.

In addition, although the porous board used the electrode plate of a present Example, the same effect is acquired also when a foam metal is used.

Explanatory drawing of the electrode plate manufacturing apparatus (shear cutting machine) which shows one Embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing of the electrode plate manufacturing apparatus (press machine) which shows one Embodiment of this invention. The shape of the electrode board cut | judged using the shear blade which shows one Embodiment of this invention. The shape of the press blade which shows one Embodiment of this invention. The processing shape of the electrode plate which shows one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shear cutting machine 11 Driving device 12 Upper shear blade 13 Lower shear blade 2 Press machine 21 Driving device 22 Punch 23 Die 3 Electrode plate original plate 4 Cutting original plate 41 Active material layer 42 Plain part 5 Belt conveyor

Claims (1)

In the manufacturing method of an electrode plate for an alkaline storage battery in which an active material layer filled with an active material in a core material and a plain portion not filled with an active material are formed and the electrode plate having a predetermined shape is manufactured by cutting the active material layer. A method for producing an electrode plate for an alkaline storage battery, wherein a portion where an active material is present is cut with a shear blade, and a portion where no active material is present is punched with a press blade.