JP2973442B2 - Coin type non-aqueous electrolyte battery and method of manufacturing the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a coin-type non-aqueous electrolyte battery and a method for manufacturing the same.

[Summary of the Invention]

The present invention provides a coin-type non-aqueous electrolyte battery using a battery container in which a negative electrode can and a positive electrode can are sealed via an insulating seal, and has a hole at the bottom of the positive electrode can, for sealing the hole. It is a battery with excellent heavy load characteristics having a stopper body, using a positive electrode can having a hole at the bottom of the can, disposing negative electrode pellets, separators, positive electrode pellets at predetermined positions, and forming a negative electrode can and a positive electrode can. After sealing through an insulating sealing, the inside of the battery container is depressurized, and then the electrolyte is sufficiently injected through the hole to the inside of the battery container, and then the hole is sealed with a plug. can get.

[Conventional technology]

A so-called non-aqueous electrolyte battery using lithium as a negative electrode active material and a non-aqueous electrolyte as an electrolyte is known as a battery having excellent storage stability with less self-discharge, and particularly having a long life of 5 to 10 years. It has been widely used as an electronic wristwatch that requires time use and various memory backup batteries. More recently, applications have expanded to devices requiring a large current, such as card-type radios, and accordingly, demands for coin-type nonaqueous electrolyte batteries having excellent heavy load characteristics have been increasing.

In general, the load characteristics of a coin-type non-aqueous electrolyte battery are greatly influenced by the amount of the electrolyte. Therefore, in order to obtain a coin-type non-aqueous electrolyte battery having excellent heavy load characteristics, inject as much electrolyte as possible. It is considered desirable. But,
It is very difficult to inject a necessary and sufficient amount of electrolyte in a short time because the positive electrode pellet and the separator have a low liquid absorption rate. For example, a coin-type non-aqueous electrolyte battery having a structure shown in FIG. 4 is conventionally known, and is manufactured as follows. Lithium is punched into a disk, and this is used as a negative electrode pellet 41. Also, heat-treated manganese dioxide,
A mixture of graphite and polytetrafluoroethylene powder is compression-molded into a disk shape, which is used as a positive electrode pellet. First, the negative electrode pellet 41 is pressed into close contact with the negative electrode can 43. Then, a separator 44 made of a non-woven fabric cut out in a circular shape is overlaid on the negative electrode pellet 41, a plastic sealing gasket 45 is further placed thereon, and an electrolytic solution is dropped from above. And on this, the positive electrode pellet
42 is placed thereon, and the electrolytic solution is dropped again. Finally, a positive electrode can 46 is covered thereon, and the end is caulked and sealed to obtain a battery.

[Problems to be solved by the invention]

However, in the above-mentioned method, even if a large amount of the electrolytic solution is dripped, the electrolytic solution cannot overflow even to the corners of the battery even if the electrolyte overflows. The present invention has been proposed in view of the above situation, and an object of the present invention is to provide a coin-type nonaqueous electrolyte battery capable of sufficiently injecting an electrolyte solution into every corner of a battery container, and a method of manufacturing the same.

[Means for solving the problem]

According to the present invention, a negative electrode pellet made of lithium or a lithium alloy, a positive electrode pellet formed by compression-molding a positive electrode active material, and a separator are housed in a battery container consisting of a negative electrode can and a positive electrode can, and the negative electrode can and the positive electrode can are insulated. A coin-type nonaqueous electrolyte battery sealed via a sex seal having a hole in the bottom of the positive electrode can and a plug for closing the hole.

Further, the present invention provides a negative electrode pellet made of lithium or a lithium alloy in contact with the inside of the negative electrode can, a positive electrode pellet formed by compression molding the positive electrode active material is disposed in contact with a positive electrode can having a hole at the bottom, and a separator The negative electrode pellet and the positive electrode pellet are arranged so as to be separated from each other, and after sealing the battery container including the negative electrode can and the positive electrode can through an insulating seal, the inside of the battery container is depressurized, And a process of injecting an electrolyte through a hole provided in the positive electrode can and then sealing the hole with a plug. The above object is achieved by the present invention.

As the negative electrode active material according to the present invention, for example, lithium,
A conductive polymer such as lithium alloy and polyacetylene, and a carbon material such as coke can be used. On the other hand, as the positive electrode active material, for example, a transition metal compound such as manganese dioxide or vanadium pentoxide, or a transition metal chalcogen compound such as iron sulfide can be used. As the electrolyte, for example, a non-aqueous electrolyte obtained by dissolving a lithium salt as an electrolyte in a non-aqueous solvent such as an organic solvent is used. Here, the organic solvent is not particularly limited, but, for example, propylene carbonate, ethylene carbonate, 1.2-dimethoxyethane, 1.2-diethoxyethane, γ-butyrolactone, tetrahydrofuran, 1.3-dioxofuran, 4-methyl-1.3 A single solvent such as dioxofuran, diethyl ether, sulfolane, methylsulfolane, acetonitrile, propionitrile, or a mixture of two or more solvents can be used. Any thing also electrolytes of known conventionally may be _{used, LiClO 4, LiAsF 6, LiPF} 4, LiB (C 6 H 5) 4, LiCl,
LiBr, CH ₃ SO ₃ Li, CF ₃ SO ₃ Li and the like.

[Action]

By closing the hole at the bottom of the positive electrode can with a plug, exhausting the inside of the battery container through the hole, reducing the pressure, injecting the electrolyte, and then sealing the hole with the plug,
A sufficiently large amount of electrolyte can be injected into every corner of the battery container, and as a result, a coin-type nonaqueous electrolyte battery having excellent heavy load characteristics can be obtained.

〔Example〕

Hereinafter, examples of the present invention and comparative examples according to the related art will be described with reference to the drawings.

Example 1 FIG. 1 is a schematic sectional view showing a battery structure according to an example of the present invention, FIG. 2 is a schematic perspective view of a perforated positive electrode can with a hole at the bottom used in the example of the present invention, and FIG. 3 is a schematic perspective view of the plug used in the embodiment. Embodiments will be described with reference to these drawings. A 1 mm thick lithium sheet was punched out into a disk shape with an outer diameter of 19.5 mm.
And Also, 89 parts by weight of heat-treated manganese dioxide, 9 parts by weight of graphite, and 2 parts by weight of polytetrafluoroethylene powder were mixed, compression-molded, and had an outer diameter of 19.5 mm and a thickness of 3 m.
m and a disk weight of 2.6 g, which were used as positive electrode pellets 12. First, the negative electrode pellet 11 was made of a negative electrode can made of stainless steel.
13 and adhered. A separator 14 made of a nonwoven fabric cut out in a circular shape was stacked on the negative electrode pellet 11, and a plastic sealing gasket 15 was further placed thereon. Then, a positive electrode pellet 12 is placed thereon, and a diameter of the stainless steel is placed on the bottom center made of stainless steel as shown in FIG.
A perforated positive electrode can 16 provided with a 2 mm hole was covered, and the end was crimped and sealed. Next, the suction nozzle was brought into close contact with the hole of the positive electrode can, and the inside of the battery can was evacuated to reduce the pressure. Then, the electrolytic solution was injected from the electrolytic solution pump. Next, a plug 17 made of stainless steel in the shape of a convex disk as shown in FIG. 3 is attached to this hole, and this portion (welded portion 18) is joined and sealed by a method of laser welding. This was designated as coin-type nonaqueous electrolyte battery A.

Here, the shape of the plug 17 was a convex disk, the diameter of the convex portion was large enough to fit into the hole of the positive electrode can, and the height was approximately the thickness of the positive electrode can. By doing so, the plug
When the device 17 is provided in the hole, the height of the upper surface of the convex portion of the plug 17 is almost equal to the height of the inner surface of the bottom of the positive electrode can 16, and the bonding area can be increased, so that the accuracy of the joint sealing is improved. I was able to. In this embodiment, the joining is performed by a laser welding method, but another method, for example, a method using an adhesive may be used.

Before assembling the battery A, the weight of each component other than the electrolyte was measured, and the weight of the completed battery was subtracted to obtain the amount of the injected electrolyte. there were.

Comparative Example FIG. 4 is a schematic sectional view showing a battery structure of a comparative example. A comparative example will be described below with reference to FIG. Each of the negative electrode pellet 41 and the positive electrode pellet 42 was produced in the same manner as in the example. First, insert the negative electrode pellet 41 into the negative electrode can.
Pressed against 43 to make it adhere. Then, a separator 44 made of a nonwoven fabric cut out in a circular shape was stacked on the negative electrode pellet 41, a plastic sealing gasket 45 was further placed thereon, and an electrolytic solution was dropped from above the separator 44. Then, the positive electrode pellet 42 is placed thereon, and the electrolytic solution is further dropped again. Finally, except that there is no hole thereon, a battery can 46 having the same shape and the same size as the positive electrode can 16 used in the embodiment is used. It was covered, and the end was crimped and sealed to obtain a coin-type non-aqueous electrolyte battery B. Before assembling the battery B, the weight of each part other than the electrolyte was measured, and the weight of the injected electrolyte was calculated by subtracting these weights from the weight of the completed battery, and the amount was 480 mg. Was.

From these results, the battery A of the example was different from the battery B of the comparative example.
This indicates that nearly 30% of the electrolyte could be injected compared to that of. Next, the discharge characteristics of the battery A and the battery B when constant-resistance discharge was performed under a heavy load of 500 ohms were measured. The results are shown in FIG. From this figure, set the cutoff voltage to 2.
When the battery discharge capacity is calculated assuming 0 V, the discharge capacity of the battery B is 425 mAH, whereas the discharge capacity of the battery A is 475 mAH.
The battery A of the example in which a large amount of the electrolyte solution could be injected has a discharge capacity improved by 10% or more compared to the battery B of the comparative example.

〔The invention's effect〕

According to the present invention, a coin-type nonaqueous electrolyte battery having excellent heavy load characteristics can be provided, and its industrial value is great.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing the structure of a coin-type nonaqueous electrolyte battery according to an embodiment of the present invention, FIG. 2 is a schematic perspective view of a perforated positive electrode can used in the embodiment, and FIG. FIG. 4 is a schematic cross-sectional view showing a structure of a coin-type non-aqueous electrolyte battery of a comparative example, and FIG. 5 is a schematic cross-sectional view of a battery A of the example and a comparative example. FIG. 9 is a discharge characteristic diagram measured for a battery B. 11 Negative electrode pellet 12 Positive electrode pellet 13 Negative electrode can 14 Separator 15 Sealing gasket 16 Positive positive electrode can 17 Plug body 18 Weld

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01M 2/02 H01M 2/36

Claims (4)

(57) [Claims] 1. A negative electrode pellet made of lithium or a lithium alloy, a positive electrode pellet obtained by compression-molding a positive electrode active material, and a separator are accommodated in a battery container consisting of a negative electrode can and a positive electrode can. A coin-type non-aqueous electrolyte battery sealed via an insulating seal, comprising: a hole in the bottom of the positive electrode can; and a plug for closing the hole. Electrolyte battery. 2. The coin-type nonaqueous electrolyte battery according to claim 1, wherein an outer peripheral edge of the separator is sandwiched between a negative electrode can and an insulating seal. 3. A negative electrode pellet made of lithium or a lithium alloy is placed in contact with a negative electrode can, and a positive electrode pellet formed by compression-molding a positive electrode material is placed in contact with a positive electrode can having a hole at the bottom. After disposing the negative electrode pellet and the positive electrode pellet so as to be separated from each other, and sealing the battery container including the negative electrode can and the positive electrode can through an insulating seal, the inside of the battery container is depressurized. A method for producing a coin-type non-aqueous electrolyte battery, comprising: a step of injecting an electrolyte through a hole provided in a positive electrode can, and a step of sealing the hole with a plug thereafter. 4. The method according to claim 4, wherein the outer periphery of the separator is sandwiched between the negative electrode can and the insulating seal when the battery container including the negative electrode can and the positive electrode can is sealed through the insulating seal. The method for manufacturing a coin-type nonaqueous electrolyte battery according to claim 3, wherein