JP2766515B2 - Button type lithium battery - Google Patents

Description

The present invention relates to a large-capacity button-type lithium battery,
In particular, the present invention relates to a structure in which the assembling accuracy is improved and a sufficient amount of the nonaqueous electrolytic solution can be secured.

<< Conventional Technology >> As a means for securing a large battery capacity of a button-type lithium battery, there is a structure in which the thickness is larger than that of a general button-type battery.

As a problem in the production of this type of battery, firstly, there is a problem in assembling, particularly a deformation problem in a case where a negative electrode terminal plate is crimped to a positive electrode can.

That is, even in this type of battery, the positive electrode can is bent inward and caulked around the outer periphery of the sealing gasket, and the peripheral edge of the negative electrode terminal plate is placed inside the sealing gasket, similarly to a conventional thin button-type lithium battery. Is involved in
At this time, the pressure applied in the vertical direction of the positive electrode can causes deformation, and the sealing may not be sufficient.

Also, the second problem is that it is necessary to ensure the absolute amount of the non-aqueous electrolyte as much as the thickness is large, and when the positive electrode mixture is injected in a state where the positive electrode mixture is housed in the positive electrode can as in the related art, If an attempt is made to ensure a sufficient amount of liquid, the liquid absorption time will be long, and the production efficiency will decrease.

As a technique for solving the first problem, for example, JP-A-58-177895 is disclosed.

This technology forms a flange on the inside of the upper part and
The positive electrode mixture is integrally molded inside the U-shaped ring,
The L-shaped part is used as a receiving base for the sealing gasket, and the caulking pressure is received at this part to prevent deformation of the positive electrode can.

Further, if this technology is developed to provide a gap between the outer periphery of the ring and the inner periphery of the positive electrode can, and a non-aqueous electrolyte can be injected into this portion, the amount of the electrolyte can be secured. .

《Problems to be solved by the invention》 However, in this structure, if a gap is formed between the positive electrode can and the positive electrode mixture, the function as a pedestal for the sealing gasket becomes unstable, and the separator for the positive electrode mixture becomes unstable. It is also difficult to perform positioning at the time of installation and positioning of the positive electrode mixture with respect to the positive electrode can, which is liable to occur during caulking, and the assembly is not always completed in an ideal state.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to improve the assembling accuracy, improve the sealing performance, and secure the required amount of electrolyte.

<< Means for Solving the Problems >> In order to achieve the above object, the present invention provides a first metal ring having a flange formed on the bottom periphery, a positive electrode mixture formed inside the first ring, A metal second ring fitted to the outer periphery of one ring and forming a flange on the upper peripheral edge, a positive electrode can containing the first and second rings and the positive electrode mixture, A negative electrode lithium laminated on the upper side via a separator, and a negative electrode terminal plate fixed to the opening of the positive electrode can by caulking via a sealing gasket; the inner periphery of the positive electrode can and the first and second rings; The upper and lower flanges defined a space for an electrolyte reservoir communicating with the positive electrode mixture.

<< Operation >> According to the above configuration, the positive electrode mixture can be accurately positioned inside the positive electrode can by the upper and lower flanges provided on each of the first and second rings.

Also, if the liquid is injected into the space defined by the flange of each ring and the inner circumference of the positive electrode can, this part can be used as an electrolyte reservoir, and the injected non-aqueous electrolyte can pass through this part inside the positive electrode mixture. Gradually penetrates.

Each flange receives pressurizing force during crimping, and especially the flange located on the upper side functions as a receiving base for the sealing gasket, so the positive electrode can is bent inward from this part as a starting point, and the sealing by crimping is performed. Done.

<< Embodiment >> Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is an exploded perspective view, and FIGS. 2 (a) to (e) are cross-sectional views showing an assembling sequence.

In the figure, reference numeral 1 denotes a shallow cylindrical positive electrode can with an open top, and 2 denotes a positive electrode can 1 via a synthetic resin sealing gasket 3.
The negative electrode terminal plate 4 is caulked and fixed to the inner peripheral portion of the opening, 4 is a positive electrode mixture mainly composed of manganese dioxide formed in a flat cylindrical shape, 5 is formed in a disk shape, and 5 The lithium negative electrode 6 provided on the inner surface is a separator made of a nonwoven fabric interposed between the positive electrode mixture 4 and the lithium negative electrode 5.

The height of the positive electrode can 1 is formed higher than that of a normal button-type battery, and a net-shaped positive electrode current collector 1a is formed on the inner bottom surface thereof.
Are integrally fixed.

As shown in FIG. 2 (a), the positive electrode mixture 4 is integrally formed inside a first ring 7 made of metal in advance.

Further, in an assembling process described later, a second ring 8 made of metal is fitted around the outer periphery of the first ring.

The first ring 7 includes a cylindrical portion 7a, a flange 7b integrally formed on a bottom peripheral edge of the cylindrical portion 7a, and a through hole 7c formed by cutting out a plurality of locations between the flange 7b and the cylindrical portion 7a.

The diameter of the flange 7a is substantially equal to the inner diameter of the positive electrode can 1. Therefore, when the positive electrode mixture 4 is installed inside the positive electrode can 1 as shown in FIG. 2 (b), the positive electrode mixture 4 is positioned at the center of the positive electrode can 1,
A gap d corresponding to the protrusion of 7b is formed between the outer peripheral portion of the cylindrical portion 7a and the inner peripheral portion of the positive electrode can 1.

Then, the non-aqueous electrolyte 9 is primarily injected through the nozzle 10 or the like with the portion of the gap d as an electrolyte pool, and then, as shown in FIG. It is fitted on the outer periphery of the ring 7.

The second ring 8 has a cylindrical portion 8a fitted to the outer periphery of the cylindrical portion 7a of the first ring 7, a flange 8b formed on the outer periphery of the upper portion of the cylindrical portion 8a, and several cutouts at the lower portion of the cylindrical portion 8a. It consists of the formed through hole 8c. The diameter of the portion of the flange 8a is substantially equal to the inner diameter of the positive electrode can 1.

Therefore, the non-aqueous electrolyte 9 is placed in a rectangular space defined by the upper and lower flanges 7b, 8b, the outer periphery of the cylindrical portion 8a and the inner periphery of the positive electrode can 1 by fitting the second ring 8 and the first ring 7 together. Is contained, the contained electrolyte 9
Gradually penetrates into the inside of the positive electrode mixture 4 through the through holes 7c and 8c.

When the cylindrical portion 8a is fitted, the upper portion of the cylindrical portion 8a forms a step which is one step higher than the surface of the positive electrode mixture 4, and due to this step, the separator 6 is installed as shown in FIG. Perform positioning at the time.

After the separator 6 is installed, use the nozzle from above the separator 6.
When the secondary injection of the non-aqueous electrolyte 9 is carried out via 10 or the like, the non-aqueous electrolyte 9 is impregnated in the separator 6, and the non-aqueous electrolyte 9 temporarily injected is dissipated or not permeated. Is supplemented.

Thereafter, the negative electrode terminal plate 2 having the sealing gasket 3 and the lithium electrode 5 provided on the inner surface thereof around the upper opening of the positive electrode can 1.
When the outer periphery of the positive electrode can 1 is bent inward and caulked, the sealing is completed as shown in FIG. 2 (e), and the inside of the battery is sealed.

During crimping, a pressing force is applied in the vertical direction of the positive electrode can 1, and if the height of the positive electrode can 1 is high, the bending state becomes unstable by itself, but the flange 8 b of the second ring 8 Since the upper and lower flanges 7b and 8b receive the entire pressurizing force, the positive electrode can 1 is bent inward from the outer peripheral edge of the flange 8b as a base, thereby improving the shape accuracy and sealing performance. You will keep it.

<< Effects of the Invention >> As described in detail in the above embodiments, in the button-type lithium battery according to the present invention, the assembly accuracy and the sealing performance when the thickness is increased in order to secure a large battery capacity are sufficiently improved. Can be secured.

According to the present invention, the space formed between the ring and the positive electrode can can be used as an electrolyte reservoir, and a sufficient amount of nonaqueous electrolyte can be injected into this portion in a short time. There are advantages such as high efficiency.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a button-type lithium battery according to the present invention, and FIGS. 2 (a) to (e) are cross-sectional views for explaining the assembling order of the battery. DESCRIPTION OF SYMBOLS 1 ... Positive electrode can 2 ... Negative electrode terminal plate 3 ... Sealing gasket 4 ... Positive electrode mixture 5 ... Lithium negative electrode 6 ... Separator 7 ... First ring 7a, 8a ... Cylindrical part 7b, 8b ... Flange 8: Second ring 9: Non-aqueous electrolyte

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Goe Yoshioka 5-36-11 Shimbashi, Minato-ku, Tokyo Inside Fuji Electric Chemical Co., Ltd. (56) References Real-life sho 59-12473 (JP, U) Kaisho 55-17298 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01M 6/16

Claims (1)

(57) [Claims] 1. A first metal ring having a flange formed on the bottom periphery, a positive electrode mixture integrally formed inside the first ring, a first ring fitted to the outer periphery of the first ring, and a top ring formed on the top periphery. A second metal ring formed with a flange;
The positive electrode can containing the second ring and the positive electrode mixture, the negative electrode lithium laminated on the upper part of the positive electrode mixture via a separator, and caulked and fixed to the opening of the positive electrode can via a sealing gasket. A button-type lithium battery comprising: a negative electrode terminal plate; and a space for an electrolyte reservoir communicating with the positive electrode mixture is defined by an inner periphery of the positive electrode can and upper and lower flanges of the first and second rings. battery.