JPH06111824A - Metal-lithium attached metal collector and manufacture thereof - Google Patents

Abstract

PURPOSE:To improve the yield rate of metal lithium, by arranging resin in a fixed pattern on the metal surface of a resin film on which metal is coated or metal foil, and press-fitting metal lithium to the part where the resin is not arranged. CONSTITUTION:A resin film 3 of at least 2-layer constitution composed of adhesive, and on which plural holes are provided at a fixed pattern, is in thermally bonded onto a metal collector 1. Then, when a metal lithium block 4 (rodlike lithium or thick lithium foil, etc., having the same width as or a little smaller than that after rolling) is arranged at a tip part in a rolling roller proceeding direction in respective holes of the film 3, and is rolled by a rolling roller 6 via a resin film 5 for preventing lithium adhering after one end is pressed to be temporarily fixed and the metal lithium block 4 is press-fitted, as metal lithium foil 7, to the surface of the collector 1. This can improve the yield rate of metal lithium.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal current collector with metal lithium for use in a thin battery having a negative electrode active material of metal lithium used in the fields of electronic equipment, toys, accessories and the like, and a negative electrode current collector thereof. The present invention relates to a method for forming metallic lithium on a substrate.

[0002]

2. Description of the Related Art Metallic lithium used in a conventional thin battery is formed by cutting a rolled metallic lithium foil into a predetermined size by means such as half-cutting and then depositing it on a metal plate serving as a current collector. By transferring, a metal current collector with metal lithium was formed. However, in such a method, lithium is not always cut at all points during the half cut,
There was a case where a partly stuck portion was generated, and during transfer, it was cut in the middle and not transferred to a predetermined shape.
In addition, the frame adhesive is placed in advance on the metal current collector,
Moreover, when the thickness of the adhesive was thicker than the thickness of the metallic lithium foil to be transferred, the transfer could not be performed.
The biggest problem is the low yield when producing metallic lithium foil, which is about 100 continuous metallic lithium blocks.
There is a loss of about 20% in rolling to the μ thickness.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to improve the yield of metallic lithium and to easily dispose it on a metallic current collector. And to provide a metal current collector with metallic lithium that enhances adhesion and a method for manufacturing the same.

[0004]

Means for Solving the Problems The present invention achieves the above-mentioned object. For a metal current collector with metallic lithium, a resin film or a metal foil coated with metal is coated with a resin in a fixed pattern on the metal surface. The metal lithium is pressure-bonded to a portion without the resin, the resin is a resin film made of an adhesive in a plurality of layers and a step is provided, and the upper surface of the metal lithium is the adhesive. The same level as or slightly lower than the stepped portion of the resin film made of the agent,
The crimping force of the peripheral edge of the metallic lithium is smaller than the crimping force of the central portion, a plurality of crimping portions of the metallic lithium are provided on the metal surface, and the total crimping area on the metallic surface of the metallic lithium is 0. As for the method for producing a metal current collector with metallic lithium, for example, it is 6% or more. For the method of producing a metal current collector with metal lithium, a resin consisting of a resin film or a resin consisting of an adhesive in which holes are formed with a certain pattern on the metal surface of a metal foil After adhering the film, a metallic lithium ingot is placed in the hole, and the metallic lithium ingot is rolled by a rolling roll in the length direction of the metal surface and pressure-bonded to the metal surface, or the metal is inserted in the hole. Simultaneously with or after the placement of the lithium foil, the metal lithium foil is hit on the metal lithium foil surface and pressure-bonded onto the metal surface, and the metal lithium mass is placed in the hole and rolled until the metal lithium is rolled. mass That at least part of which is crimped to the metal surface by pressing, striking the metal lithium foil hammer - characterized in such that exerted by the press, but they by solving the aforementioned problems.

[0005]

According to the first aspect of the invention, a series of metal current collectors provided with an adhesive and to which metal lithium is pressure-bonded can be obtained, and the steps during battery production can be continuously and rapidly automated. According to the second and third aspects, another battery element (that is, a positive electrode active material, an electrolyte, etc.) can be arranged at a position where there is a thickness difference between the adhesive and metallic lithium. According to the fourth aspect, the electric conductivity of the peripheral portion of the metallic lithium is reduced to reduce the charging current density, suppress the formation of dendrites of metallic lithium, and prevent damage to the battery due to an internal short circuit. According to the fifth aspect, it is possible to disperse the pressure bonding of metallic lithium to the metal surface and to achieve both electrical contact and mechanical holding. According to the sixth aspect, the minimum necessary pressure bonding for electrical contact and mechanical holding of metallic lithium is performed, and the pressure bonding process step is reliably and simplified. According to claim 7, a lithium metal lump is placed on a metal current collector to which an adhesive having holes is formed in a predetermined pattern in a predetermined shape is adhered and rolled to obtain a predetermined shape (a shape corresponding to the shape of the hole). A metallic lithium foil is obtained, and the problems due to transfer are eliminated. An arbitrary foil thickness can be obtained by adjusting the amount of metallic lithium ingot and the thickness during rolling. Further, the yield of the metallic lithium ingot is further improved.
In addition, handling of metallic lithium becomes easy. Further, in the case where there is a large step between the adhesive and the metallic lithium, crimping and fixing by hitting the metallic lithium foil is a simple and reliable method from the viewpoint of electrical contact and holding with the current collector. According to the eighth aspect, the positional deviation is prevented, and the processing speed of rolling and press-bonding to a predetermined shape of metallic lithium is improved. In addition, the accuracy of processing into a predetermined shape is improved. According to claim 9, high speed automation of the pressure fixing process of metallic lithium can be achieved.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. (Example 1) A metal current collector with metallic lithium and a method for manufacturing the same will be described. Metal current collector 1 (width: about 300 mm, thickness: about 2
0 μ, material: copper foil, stainless steel foil, nickel foil, resin film on which copper is vapor deposited, and the like can be used. ) On a fixed pattern with holes 2 (shape; square,
Vertical and horizontal lengths: about 2.5 cm and about 2.3 cm, depth: about 0.4 mm) and a resin film 3 (at least two layers) made of an adhesive provided at equal intervals (about 6 mm). Structure: First layer resin film 3'and second layer resin film 3 ", structure of each resin film: Modified PP-core material PET
Or, three layers of aluminum foil-modified PP, thickness; first layer resin film 3'is about 0.1 mm, second layer resin film 3 "is about 0.3 mm, shape of each hole; first layer resin film 3 'Is about 2.3 cm, the second layer resin film 3''is about 2.3 cm.
FIG. 1 (each pattern is enlarged in FIG. 1) shows a planar state when 5 mm) is heat-bonded. FIG. 2 shows a sectional view in the length direction at that time (the same applies to the width direction). It is preferable that the upper surface of the second layer resin film 3 ″ made of an adhesive is provided with a release paper for preventing contamination. Further, the adhesive may be a fluid resin, and after the metallic lithium is placed. It is also possible to arrange the fluid resin in a fixed pattern.Next, a method of arranging metallic lithium by a rolling roll is outlined in the sectional view of FIG. A metallic lithium ingot 4 (such as rod-shaped lithium having a width equal to or slightly smaller than the width after rolling or a thick lithium foil) is arranged at the tip of the resin film 3 in each hole 2 in the traveling direction, and one end After being pressed and temporarily fixed, it is rolled by a rolling roll 6 through a resin film 5 for preventing lithium adhesion such as PET, and at the same time, a metal lithium foil 7 is pressure-bonded to the surface of the metal current collector 1. Rolling and rolling of electric body 1 The metal lithium foil 7 is formed on the metal current collector 1 by rotating the rolling roll 6. In this case, when the surface of the rolling roll 6 is resin-processed to prevent metal lithium from adhering, Although the rolling surface is slightly deformed due to processing, it is not possible to obtain a predetermined thickness at one time and it is necessary to roll several times, but it is necessary to arrange the lithium adhesion preventing resin film 5 by another mechanism. Next, the crimping of the metal lithium foil onto the surface of the metal current collector by hitting will be described (Example 2) As shown in the cross-sectional view of Fig. 4, the same hole 2 shape as that produced in Example 1 was used. A resin film 3 made of an adhesive having a copper foil 8 was deposited on the resin film 9 by vapor deposition and bonded to the metal current collector surface of the hole 2 with a metal lithium foil 10 (shape: about 2.3 mm square, Thickness: about 0.1 mm)
Were collectively placed in a plurality of holes by a transfer device such as a robot. Next, an impact mark (about 110 mm) having a diameter of about 5 mm is formed in the central portion of the metallic lithium foil 10 arranged by the hammer-press device 11.
This is equivalent to dropping a g weight from a height of about 9 cm. ) Is applied and crimped (a portion corresponding to the black portion 12 in the figure)
did.

[0007] The yield of metallic lithium was improved to about 98% by the above production. About 2% of the defects were due to the deviation of the hole shape of the resin film made of the adhesive. It was improved by about 18% compared to the conventional one. Electrical contact was maintained by setting the total pressure-bonded area to 0.6% or more of the total surface area. If it is 0.6% or less, the electrical resistance of the current collector (for example, what was about 0.62Ω increases to about 0.87Ω or more) and the charge / discharge characteristics deteriorate. On the other hand, when it is 0.6% or more, the electrical resistance of the current collector is in the range of about 0.57 Ω to about 0.62 Ω, which is almost stable. In addition, when a battery having a lower pressure-bonding force on the periphery of metallic lithium was assembled into a battery, formation of dendrites of metallic lithium on the periphery was not observed even when charged at a current density of about 3.6 times that of a conventional battery. By setting the metal lithium to be equal to or lower than the stepped portion of the resin film made of an adhesive, the peripheral portions of the battery element on the positive electrode side and the battery element on the negative electrode side are separated, and an internal short circuit is prevented. In addition, when rolling a metallic lithium ingot by the inclination angle of the stepped portion,
The movement of the smoother becomes smooth and the surface of the metallic lithium after rolling becomes smooth.

[0008]

As described above, the present invention has the following effects. (1) The yield of metallic lithium is improved by about 18%. (2) The placement of metallic lithium is facilitated. (3) Adhesion to the current collector is improved because pressure is applied simultaneously with rolling. (4) Internal short circuit can be prevented. (5) Suppress the dendrite short of lithium. (6) Increased productivity. Note that the present invention is not limited to those shown in the examples, but the shape of each current collector, the resin film material / thickness, the shape of the holes, the pattern shape / number, the amount of metallic lithium mass,
The shape, thickness / width / length / corner shape of the metallic lithium foil, pressure-bonding method by hitting, single area, etc. are not particularly limited and may be changed depending on the application.

[Brief description of drawings]

FIG. 1 is a plan view of a metal current collector to which a resin film made of an adhesive according to the present invention is adhered.

FIG. 2 is a cross-sectional view of a main part in the length direction of FIG.

FIG. 3 is a cross-sectional view showing a metallic lithium foil formation state according to the present invention.

FIG. 4 is a cross-sectional view showing a state of pressure-bonding formation by hitting a foil of metallic lithium according to the present invention.

[Explanation of symbols]

 1 Metal Current Collector 2 Holes 3 Resin Film Made of Adhesive 4 Metal Lithium Lump 6 Rolling Roll 7 10 Metal Lithium Foil 8 Copper Foil 9 Resin Film 11 Hammer Press Machine 11 12 Crimping Section

Claims (9)

[Claims] 1. A metal lithium comprising a resin film or a metal foil coated with a metal, the resin being arranged in a fixed pattern on a metal surface, and the metal lithium being pressure-bonded to a portion without the resin. Attached metal current collector. 2. The metal current collector with metal lithium according to claim 1, wherein the resin is a resin film made of an adhesive and is made up of a plurality of layers, and a step is provided. 3. The metallic current collector with metallic lithium according to claim 1, wherein the upper surface of the metallic lithium is at the same level as or slightly lower than the step portion of the resin film made of the adhesive. 4. The metal current collector with metallic lithium according to claim 1, wherein the pressure of the peripheral edge of the metallic lithium is smaller than the pressure of the central portion. 5. The metal current collector with metal lithium according to claim 1, wherein a plurality of the pressure-bonded portions of the metal lithium are provided on the metal surface. 6. The total pressure-bonded area on the metal surface of the metallic lithium is 0.6% or more.
A metal current collector with the described metal lithium. 7. A metal film coated with a metal or a metal foil is adhered with a resin film made of an adhesive in which holes are formed with a certain pattern on the metal surface of the metal foil, and a lithium metal block is placed in the holes. Further, a metal lithium block is rolled by a rolling roll in the length direction of the metal surface and pressure-bonded to the metal surface, or at the same time as or after the metal lithium foil is placed in the hole, on the metal lithium foil surface. A method for producing a metal current collector with metal lithium, which comprises hitting a metal lithium foil onto a metal surface by pressure. 8. The lithium metal according to claim 7, wherein at least a part of the lithium metal block is pressed onto the metal surface by pressing before the metal lithium block is placed in the hole and rolled. Method for manufacturing a metal collector having an electrode. 9. The method for producing a metal current collector with metal lithium according to claim 7, wherein the impact of the metal lithium foil is applied by a hammer press.