JPS635177Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a sealed battery, particularly a battery in which a power generation element consisting of a positive electrode, a light metal negative electrode, and an organic electrolyte is sealed within a battery case.

Generally, metal fluorides, oxides, or chlorides are used as positive electrode active materials, and lithium,
In so-called organic electrolyte batteries that use active light metals such as magnesium and aluminum in combination with organic electrolytes, metal parts that make up parts such as positive electrode current collectors, lead plates, sealing plates, etc. that come into contact with the positive electrode inside the battery, etc. When metals such as iron, nickel, and copper are used in the battery, these metals often dissolve in a type of electrochemical reaction with the positive electrode, significantly deteriorating battery performance. For this reason, high-purity aluminum, which is resistant to organic electrolytes, is used in the areas mentioned above.
Titanium and tantalum are used. There was an assembly sealing plate mainly made of synthetic resin using these metal plates, as shown in FIG.

That is, as shown in the exploded view shown in FIG. 3, the assembled sealing plate 1 shown in FIG. Rivet terminal 3 consisting of
With the head 3a inside the battery, insert the washer 4 with a tab made of titanium in a fitted state, and attach a rivet leg 3b protruding to the outside of the battery with a material that is easy to work with, can be welded, and is strong, such as iron. A nickel-plated washer 5 is fitted into the body, and the leg portion 3b is caulked and deformed to integrate the washer 5 with the sealing body 2. Further, a terminal cap 6 made of nickel-plated iron is spot-welded to the washer 5 so as to surround the rivet leg 3b which has been deformed by caulking. FIG. 4 is a half sectional view showing the completed assembled sealing plate 1.

When the opening of the battery case 7 is sealed with the assembled sealing plate 1 having such a structure as shown in FIG. head 3
Electrical continuity is ensured by making surface contact with a by caulking deformation pressure. Therefore, if a thin oxide film is already formed on the head of the aluminum rivet during use, or if the battery is used in a cold atmosphere, the synthetic resin sealing body 2 may shrink in diameter and thickness, causing the rivet head to shrink. There was a problem in that the contact between the portion 3a and the washer 4 became loose, making it impossible to obtain sufficient battery output.

In this invention, a rivet made of aluminum with a titanium washer press-fitted into the large diameter part of the shaft is inserted into a through hole provided in the center of a synthetic resin sealing plate so that its head is located inside the battery. A cap mounting washer that is easy to weld is fitted to the rivet leg protruding from the rivet leg, and the washer is integrated into the sealing plate by caulking and deforming the rivet leg, and the terminal cap is attached to this washer so as to surround the deformed leg. The main purpose of this project is to solve the drawbacks of the conventional technology and stabilize battery quality by using an assembled sealing plate that is welded together. The present invention will be described in detail below based on examples.

In Fig. 1, 9 is an assembly sealing plate that is a feature of the present invention, 10 is an aluminum rivet with a diameter larger than the other parts at the base of the shaft, and 11 is an aluminum rivet with a diameter larger than the head of the aluminum rivet. It is a thick titanium washer. 12 is a positive electrode plate made of carbon fluoride as an active material and coated on a metal net, 13 is a negative electrode plate made of lithium, and 14 is a positive electrode 12 and a negative electrode 13.
A separator made of an electrolyte-resistant non-woven fabric was interposed between the two, and γ-butyrolactone in which a lithium salt such as lithium borofluoride was dissolved was used as the organic electrolyte. 7 is a battery case made of nickel-plated iron that also serves as a cathode terminal. Next, assemble the sealing plate 9
I will explain in detail. In the exploded view shown in Fig. 5, 2 is a sealing plate made of electrolyte-resistant thermoplastic resin plate and having a through hole 2a in the center. An annular convex portion 2b is provided around the upper surface of the sealing plate in order to increase the sealing plate. Reference numeral 10 denotes a rivet made of aluminum that is resistant to electrolyte and has excellent workability, and the base portion 10a of the shaft portion is made larger in diameter than the other portions, and this large diameter portion is press-fitted into the washer 11 made of titanium. Figure 6 A,
B and C show assembly drawings of this part, and Fig. 7 shows the inner diameter A of the washer 11 and the large diameter part 10a of the rivet shaft.
shows the relationship with the diameter B, where B is 0.1 to 0.5 larger than A.
It is formed larger in mm. The head 10b of this rivet 10 is placed inside the battery, and its shaft is inserted into the through hole 2a of the polypropylene sealing body, and the leg 10c is fitted with a cap mounting washer 5 made of nickel-plated iron that is easy to weld. The washer 5 is integrated into the sealing body 2 by caulking and deforming the portion 10c, and a terminal cap 6 made of the same material as the washer 5, that is, iron plated with nickel, is attached to the washer 5.
It consists of spot welding. FIG. 8 shows a half-sectional view of the completed assembled sealing plate 9, in which the titanium washer 11 press-fitted into the large diameter portion 10a of the shaft portion of the aluminum rivet 10 ensures reliable electrical conduction, and the rivet head The positive titanium lead 8 can be spot-welded directly to the washer 11, which has a larger diameter than the washer 10b and is thicker than the conventional one.

Therefore, by press-fitting the large diameter part of the base of the shaft of the aluminum rivet 10 into the inner diameter part of the titanium washer 11, the electrical and physical fixation of both is ensured, and the surface of the aluminum rivet or the titanium washer is secured. Even if an oxide film were formed on the inner diameter part of the rivet, the deformation of the large diameter part of the rivet during press-fitting would strip it off, resulting in extremely good electrical continuity. Moreover, even if the polypropylene sealing plate 2 contracts in cold weather, the rivet 10 and washer 11 are in a press-fit relationship, so that contact failure will not occur. 9A and 9B are half-sectional views showing another example of the aluminum rivet according to the present invention.
In addition to the one with d, we also use one in which the entire shaft is tapered so that the diameter gradually decreases from the base to the tip, as shown in b, so that the outer diameter B of the shaft tip is smaller than the inner diameter A of the washer 11. It is possible.

To assemble the battery, a power generation element formed by spirally winding a separator 14 interposed between a positive electrode plate 12 and a negative electrode plate 13 is inserted into the battery case 7, and a stepped portion is inserted near the open end of the battery case 7. 15, and after completing the electrolyte injection, connect the titanium lead 8 of the positive electrode plate 12 to the titanium washer 11 attached to the sealing plate 9 with rivets by a method such as ultrasonic welding, and then attach the assembled sealing plate 9 to the battery case. 7, the opening 16 of the case 7 is bent inward, and the annular protrusion 2b of the sealing plate 2 is tightened.

In addition, the lead 8 of the positive electrode plate 12 is connected to the titanium washer 1.
In addition to the method described above, the lead 8 may be attached to the washer 11 by stacking it on the flat surface of the edge protruding from the rivet head of the washer 11 and connecting it by a method such as spot welding.

According to this example, the aluminum rivet and the titanium washer were press-fitted, so there was no possibility of loosening between them, and there was no chance of short circuits occurring inside or outside the battery, or if the battery was stored at a high temperature of 80°C for 24 hours. Even in this case, as shown in FIG. 10, there is almost no increase in the internal resistance of the battery, and it can be expected that the battery will exhibit superior high-temperature storage characteristics compared to the conventional product shown in FIG. 11. The number of samples was 100 in each case. In addition, the reason for using aluminum for the rivets is that titanium and tantalum have poor workability as rivets, and it is difficult to form the large diameter part of the shaft with good dimensional accuracy and crimping the leg side due to its characteristics. Aluminum rivets should be used because sufficient caulking strength cannot be obtained for various reasons, poor adhesion with the resin sealing plate and washers may reduce airtightness, and the material is expensive. According to
The above-mentioned drawbacks of titanium and tantalum could be eliminated. Furthermore, by press-fitting the large diameter part of the rivet shaft into a titanium washer, this part can be ensured to be airtight and liquid-tight, and the aluminum rivet legs, which are easy to swage, can be used to attach the cap mounting washer to the outside of the sealing plate. It can be caulked to the sealing plate, and even if you use the iron plated with nickel, which is normally used for cap mounting washers,
Since the washer is located outside the battery, it does not undergo an electrochemical reaction with the positive electrode and be consumed. In addition, since the terminal cap is also the same, by using nickel-plated iron, which is commonly used, compared to the conventional example, it is possible to secure electrical continuity by press-fitting the aluminum rivet and titanium washer. It is possible to improve the welding strength when spot welding the terminal cap to its mounting washer, improve the caulking workability of the rivet, and improve the electrical conductivity of the positive electrode lead lead-out portion.

[Brief explanation of drawings]

Fig. 1 is a sectional view of the main parts of a sealed organic electrolyte battery according to an embodiment of the present invention, Fig. 2 is a sectional view of the main parts of a conventional similar battery, and Fig. 3 is an exploded view of the assembled sealing plate used in the conventional battery. Fig. 4 is a half-sectional view of the completed assembly, Fig. 5 is an exploded view of the assembled sealing plate used in the battery of the present invention, and Fig. 6 A, B, and C show aluminum rivets and titanium washers. Figure 7 is a diagram showing the dimensional relationship between the large diameter part of the rivet's shaft and the inside diameter of the washer before press-fitting, Figure 8 is a half-sectional view showing the completed assembled sealing plate, Figure 9 is a diagram showing the press-fit assembly of the rivet. Figures A and B are half-sectional views showing other examples of aluminum rivets according to the present invention, Figure 10 is a diagram showing the storage characteristics of the battery according to the invention, and Figure 11 is a diagram showing the storage characteristics of a conventional battery. . 2...Synthetic resin sealing plate, 2a...Through hole, 5...
Cap mounting washer, 6...terminal cap,
8... Positive electrode lead, 9... Assembly sealing plate, 10...
Aluminum rivet, 10a... Large diameter part of rivet shaft, 10b... Rivet head, 10c...
The leg portion of the rivet to be caulked, 11...Titanium washer, A...Inner diameter of the washer, B...Diameter of the large diameter portion of the rivet.

Claims (1)

[Scope of claims for utility model registration] (1) Positive electrode 12, light metal negative electrode 13, separator 14
and an assembled seal mainly consisting of a power generation element made of an organic electrolyte, a battery case 7 housing this power generation element, and a sealing plate made of a synthetic resin having electrolyte resistance for sealing the opening of the battery case 7. The assembly sealing plate 9 is composed of an aluminum rivet 10 having a large diameter head 10b at one end of a shaft portion 10a and a caulking leg portion 10c at the other end, and a shaft portion of this rivet. A titanium washer 11 into which the large diameter part is press-fitted, a synthetic resin sealing plate 2 with the rivet shaft part inserted into the central through hole 2a from the inside to the outside, and the leg part 10 of the rivet.
The cap mounting washer 5 is fitted onto the cap mounting washer 5 and the leg portion 10 c is integrated onto the sealing plate 2 by the caulking deformation of the leg portion 10 c, and the leg portion 10 is deformed by caulking of the rivet.
Washers 5 for cap mounting surround c.
A sealed battery consisting of a terminal cap 6 welded to the terminal cap 6. (2) The titanium washer 11 into which the large diameter portion of the shaft portion of the aluminum rivet 10 is press-fitted has a larger diameter than the rivet head 10b, and is suitable for utility model registration to which one electrode lead of the power generation element is connected. Sealed batteries as described in scope 1.