JPH11260375A - Battery active material holding material and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-cost battery active material holding material with high strength, low electrical resistance, high active material holding force, and provide its manufacturing method. SOLUTION: A battery active material holding material is manufactured in such a way that a plurality of slits 2 are formed in the surroundings of the center point of a piece of metal plate 1, and by pressing the vicinity of the center point, the slit parts are raised up to form a lath mesh-shaped cylinder part 34. By forming the lath mesh-shaped cylinder with raised up slit parts, active material holding performance is increased, and capacity drop caused by the coming off of an active material is decreased. Since the surface area is larger than a metal net, a punched sheet, a thin plate, or the like, high current collecting efficiency is obtained, and the capacity of the battery can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active material holding material for a positive electrode and a negative electrode used in a secondary battery (for example, a lithium secondary battery) and a method for producing the same.

[0002]

2. Description of the Related Art An active material holding material used in a battery has a role as a current collector for extracting current from the active material, a role to hold and fix the active material, and a strength member to prevent breakage during battery assembly. There are roles.

Conventionally, a metal net, a punched sheet, a thin plate or a porous body has been used as a battery active material holding material having such a role.

[0004]

However, when the opening degree is increased in order to secure the active material holding power, the mesh and the punched sheet are insufficient in conductivity and strength, and are increased in thickness to compensate for this. However, there is a disadvantage that battery capacity is sacrificed.

Further, a thin plate requires a large amount of an active material binder in order to secure the active material holding power, and thus has a disadvantage in that the battery capacity is sacrificed.

[0006] Further, after plating a metal material on a base material such as urethane foam or non-woven fabric, or after adhering a metal powder,
Each of the porous metal bodies obtained by sintering has a drawback that the production method is complicated and the production cost is high.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned drawbacks of the prior art, and it is an object of the present invention to provide a low-cost battery active material holding material having high strength, low electric resistance and excellent holding power for an active material, and a method for manufacturing the same. For the purpose of providing.

[0008]

In order to achieve the above object, the present invention comprises a single metal plate, a plurality of slits are formed around one point on the metal plate, and the center is formed. The present invention provides a battery active material holding material, wherein a gap between the slits is caused by pressing the vicinity, and the slits are formed as a lath net-like cylindrical portion.

Further, the present invention is characterized in that a plurality of slits are formed around one point on one metal plate as a center, and by pressing the vicinity of the center, the gap between the slits is caused to occur. It is intended to provide a method for producing a battery active material holding material, wherein the portion is formed as a lath net-like cylindrical portion.

In the holding member and the method of manufacturing the holding member, preferably, a plurality of the cylindrical portions are provided on the metal plate. Also,
The thickness of the metal plate is preferably 200 μm or less. Further, preferably, a metal material is plated on the metal plate.

[0011]

An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a perspective view schematically showing one embodiment of a battery active material holding material 10 according to the present invention. As shown in FIG. 1, the battery active material holding material 10
Has a large number of slits 2 formed on a metal plate 1,
A lath net-like cylindrical portion 3 formed by raising the slit portion is provided, and a metal material is plated on the metal plate 1.

The metal plate 1 is made of iron, stainless steel, nickel,
Aluminum, copper, etc., slit 2
Can be formed by press working or the like. Also,
The metal material to be plated on the metal plate 1 is nickel, chromium,
It can be copper or an alloy thereof.

An embodiment of a method for manufacturing the battery active material holding material 10 will be described below. As shown in FIG. 2, a circular hole 4 having a diameter of 1 mm is formed in the metal plate 1. 1mm curved slit 2
Are formed at equal intervals in the circumferential direction. In addition, slit 2
Is appropriately selected in consideration of the degree of formation of the lath net-like tubular portion 3 described later.

Next, as shown in FIG. 3, the periphery of the slit 2 of the metal plate 1 in which the slit 2 is formed is pushed down to raise the slit forming portion into a conical shape, thereby forming the mesh tubular portion 3.
The shape of the slit 2 may be any shape as long as it can form the lath net-like tubular portion 3. For example, in addition to the curve as in the present embodiment,
It may be a straight line. Further, it is also possible to form a multi-stage cylindrical portion by making each slit discontinuous at a position equidistant from the center and making it intermittent. FIG. 1 shows an example in which each slit is interrupted at two places. In addition, it is preferable that the center hole 4 has a diameter of 3 mm or less in order to maintain the holding performance of the active material and minimize the decrease in conductivity. The hole 4 can be polygonal in addition to circular.

The plating of a metal material is performed for the purpose of exhibiting conductivity and contact resistance, and is particularly effective when iron or stainless steel is used as the metal plate 1. For example, when an iron foil having a thickness of 50 μm is used as the metal plate 1, 3
It is preferable to coat nickel with a thickness of about μm by plating.

FIG. 4 is a schematic view of a facility for continuously producing the battery active material holding material 10. The metal plate on the roll is introduced into the press-cutting machine 5, where the slit 2 is formed.
Next, the reticulated tubular portion 3 is formed by the roll 6 having projections on the peripheral surface. Next, the metal plate 1 is introduced into the metal surface treatment tank 7 and the entire surface of the metal plate 1 on which the reticulated tubular portion 3 is formed is coated with a metal material by plating. Next, it is wound up in a roll through a post-treatment process such as a washing treatment tank 8 and finally a drying treatment machine 9.

[0017]

The battery active material holding material according to the present invention is formed from a single metal plate, a plurality of slits are formed around a single point on the metal plate, and a central portion thereof is pressed. By doing so, the slit portions are raised to form a lath net-like cylindrical portion, so that the active material holding performance is excellent, and the capacity decrease due to the falling off of the active material is small. Also,
Since the surface area is larger than that of a metal net, a punched sheet, a thin plate, or the like, high current collection efficiency can be obtained, and the capacity of the battery can be improved.

Further, the battery active material holding material according to the present invention comprises:
Since it is formed from a metal plate, it has high strength, and there is almost no possibility of breakage in a working operation in a continuous coating facility for active materials and a battery assembly facility.

Further, since it is manufactured by a simple manufacturing method, there is an advantage that the cost is low.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing one embodiment of a battery active material holding material according to the present invention.

FIG. 2 is a plan view showing a metal plate in a state where slits are formed in one embodiment of the method for manufacturing a battery active material holding material according to the present invention.

FIG. 3 is a perspective view showing a state in which a mesh tubular portion is formed on the metal plate shown in FIG. 2;

FIG. 4 is a front view schematically showing an embodiment of a facility for continuously producing a battery active material holding material according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal plate 2 Slit 3 Reticulated tube part 4 Hole 5 Press cut machine 6 Roll 7 Metal surface treatment tank 8 Cleaning treatment tank 9 Drying machine 10 Battery active material holding material

Claims (8)

[Claims] 1. A single metal plate is formed, a plurality of slits are formed around one point on the metal plate as a center, and a slit strip portion is raised by pressing the vicinity of the center to form a lath. A battery active material holding material having a net-like cylindrical portion. 2. The battery active material holding material according to claim 1, wherein a plurality of the cylindrical portions are provided on the metal plate. 3. The battery active material holding material according to claim 1, wherein the thickness of the metal plate is 200 μm or less. 4. The battery active material holding material according to claim 1, wherein a metal material is plated on the metal plate. 5. A plurality of slits are formed around one point on one metal plate around the center, and by pressing the vicinity of the center, a slit portion is raised to form a lath net-like cylindrical portion. A method for producing a battery active material holding material, comprising: 6. The method according to claim 5, wherein a plurality of the cylindrical portions are provided on the metal plate. 7. The method for producing a battery active material holding material according to claim 5, wherein the thickness of the metal plate is 200 μm or less. 8. The method for producing a battery active material holding material according to claim 5, wherein a metal material is plated on the metal plate.