JPS6345759A - Cylindrical nonaqueous electrolyte battery - Google Patents

Abstract

PURPOSE:To prevent internal short circuit at the end by removing positive active material from the winding end of a positive plate to expose a metal supporter, and fixing a metal plate to the exposed part of the metal supporter. CONSTITUTION:A part of positive active material 1 is removed to expose a metal supporter 2, and a metal plate 3 is fixed to the supporter by spot-welding. Since the burr of the metal supporter and warp at the end of the metal supporter have a harmful effect on the outside, the metal plate 3 is fixed to surface, which is faced to the outside in winding, of the positive plate. The metal plate is extruded from the end of the metal supporter so as to cover its end. A folded metal plate may be used as the metal plate 3, and the inside of the folded part is butted to the winding end of the positive plate so as to cover the end and make positioning easy. Since the both sides of the metal plate, on which welding terminals are placed, are flat, spot welding job is made easy. Problems generating internal short circuit are reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a positive electrode plate for a cylindrical non-aqueous electrolyte battery.

[Conventional technology]

Conventionally, in cylindrical batteries in which elongated positive and negative electrode plates are spirally wound with a separator in between, the positive electrode plate is made by supporting a positive electrode active material on a porous metal support such as wire mesh, punched metal, lath metal, etc. Because of its use, the positive electrode plate had rebound resistance against bending. Therefore, a force directed outward was particularly exerted at the end of the winding. On the other hand, since this positive electrode plate was formed into a long length and then used for punching, cutting, etc. into a predetermined shape, cracks were generated on the metal support during punching and cutting.

Therefore, when the metal support material formed at the end of the positive electrode plate is pressed outward, it penetrates through the separator and comes into contact with the negative electrode plate and the battery container holding the negative electrode terminal, causing an internal short circuit. There were drawbacks. Furthermore, a similar phenomenon occurred when the ends of the support were folded back even when no breakage occurred. Therefore, an adhesive tape made of electrolyte such as polypropylene was attached to the winding end of the positive electrode plate as a protective measure.

[Problem that the invention seeks to solve]

However, since adhesive tapes do not have sufficient strength to correct burrs, folded edges at the ends of the support, etc., the adhesive tape must be thick enough to absorb the height of burrs, etc. In addition, if the positive electrode active material adheres to the attachment part, the adhesiveness of the tape will deteriorate because the positive electrode active material is originally in powder form, so the positive electrode active material in the core part had to be completely removed. . Furthermore, since non-aqueous electrolyte batteries do not like trace amounts of moisture,
It was necessary to manufacture batteries in a glove box with an atmosphere of argon, dry air, etc. from which moisture had been removed.

Furthermore, since the positive electrode plate also contains adsorbed water, bound water, etc., it was necessary to perform a heating dehydration treatment before transporting it into the glove box. The temperature is generally about 200° C. to 300° C., which is a temperature that adhesive tapes made of resin, polypropylene, etc. cannot withstand.

Therefore, the adhesive tape must be attached after the positive electrode plate has been heated and dehydrated, that is, in a glove box, and this work is extremely difficult.

In order to solve these conventional drawbacks, the present invention creates a highly reliable cylinder with no internal short circuit at the end by fixing a metal plate to the end of the winding of the positive electrode plate by spot explosion welding or the like. The purpose of the present invention is to provide a type non-aqueous electrolyte battery.

[Means for Solving the Problems] 'The present invention provides a positive electrode active material mainly composed of manganese dioxide, graphite fluoride, iron sulfide, etc., on a porous metal support such as gold silk, punched metal, or lath metal. A long positive electrode plate carrying lithium,
A long negative electrode plate made of a light metal such as sodium is spirally wound with a separator interposed therebetween, and is stored in a battery container along with an electrolyte solution in which a supporting electrolyte such as lithium perchlorate is dissolved in a non-aqueous solvent. , a cylindrical nonaqueous electrolyte battery with a sealed opening, in which the positive electrode active material at the end of the winding of the positive electrode plate is removed to expose the metal support, and the exposed part of the metal support is removed from the outside of the winding. This is a cylindrical non-aqueous electrolyte battery characterized by having a metal plate fixed to it by spot explosion welding or the like.

[Effect]

As described above, the present invention is achieved by fixing a metal plate to the winding end of the positive electrode plate by spot explosion welding or the like, (a) to improve the strength against breakage, folding of the end of the support, etc. It is sufficient that the thickness of the metal plate is approximately 0.0111 mm or more.

(b) The removal of the positive electrode active material from the metal plate fixing portion may be incomplete.

(c) Spot welding can be performed before the positive electrode plate is heated and dehydrated, that is, outside the glove box.

etc., the workability is much easier than the conventional technology. Note that the material of the metal plate used only needs to be stable within the battery, and there is a wide range of choices, such as various types of stainless steel, titanium, tungsten, etc.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the winding end of the positive electrode plate according to the present invention. A portion of the positive electrode active material 1 is removed to expose the metal support 2, and a metal plate 3 is fixed thereto by spot blast welding. Since the edges of the metal support 2, the folds at the ends of the support, etc. mainly exert a negative effect on the outside, the metal plate 3 only needs to be fixed to the surface facing outside when the positive electrode plate is wound. . Its length is such that it extends from the end of the metal support 2 so as to cover the end of the metal support 2. Further, the metal plate 3 may be one metal plate bent in two as shown in FIG. 2, with the folded part facing the end of the winding of the positive electrode plate, as shown in FIG. Place it on the inside of the folded part so as to cover the end part,
It becomes easy to align the two. Furthermore, when spot welding,
Since both surfaces of the metal plate on which the spot terminals are brought into contact are flat, the work in step 7 is also facilitated. Furthermore, in both of the above examples, the width may be equal to the width of the electrode plate, but by making it larger, it is possible to cover the cracks that occur at the upper and lower ends near the ends of the metal support. It is possible to improve its reliability. Also, the end of winding υ of the metal plate
Internal short circuits due to the corners of the metal plate can be prevented by making the corners of the metal plate arcuate as shown in Figure 3 or rounded as shown in Figure 4 to avoid sharp edges. It is possible to reduce the risk, and furthermore, by fixing the metal plate so that the edges are directed inward when forming the metal plate, its reliability can be improved.

Below, an example in which the present invention is applied to a cylindrical manganese dioxide-lithium non-aqueous electrolyte battery will be explained in comparison with a conventional one. Figure 5 shows the winding end of the positive electrode plate.
A positive electrode active material 51 such as manganese dioxide, graphite as a conductive agent, and a binder such as polytetra 70 loethane is supported on a support 52 made of lath metal of S'VS304 to form a positive electrode plate.

The positive electrode active material is removed from the end by a width of 5 nO to expose the support 52. Here, the metal plates illustrated in FIG. 3 are solidified by spot welding as the invention product [A] and the second
For comparison, the two-folded υ metal plate solidified by spot welding is the product of the present invention CB), with a thickness of Q, 9
A conventional product (CD) was attached with a 5 mm polypropylene adhesive tape, and a conventional product (D) was attached with a 0.2 nm thick polypropylene tape, and 100 prototypes of each were produced. Table 1 shows the results of investigating the number of peeled pieces of the polypropylene adhesive tape and metal plate at that time. Furthermore, the product of the present invention (A
) and [B] are both SM'5304 with a thickness of Q and Qlmm. When the peeling state of conventional products (C) and (D) was examined, it was found that the positive electrode active material powder that could not be completely removed was attached to the adhesive surface of the tape. This defective product was made into a non-defective product by removing the adhesive tape and turning it over 9 times to completely remove the positive electrode active material powder. next,
Batteries were assembled using each of the positive electrode plates, and 30 of each were subjected to a vibration test and a free fall test. Table 2 shows the number of internal short circuits that occurred at that time. The presence or absence of an internal short circuit was confirmed by the change in open circuit voltage before and after arming. Furthermore, when conventional polypropylene adhesive tapes (CD, CD) were used, some internal short circuits occurred during battery assembly, so the number of such tapes is also listed in Table 2.
4 Table 1 Table 2 [Effects of the Invention] As described above, the present invention can provide a cylindrical non-aqueous electrolyte battery that greatly improves manufacturing workability and has extremely high reliability.

[Brief explanation of drawings]

FIG. 1 is a developed view of the positive electrode plate and metal plate of the present invention, and FIG. 2 is a developed view of the positive electrode plate when a two-folded metal plate is used. FIGS. 3 and 4 are diagrams of a metal plate cut into corners. FIG. 5 is a perspective view of the winding end of the positive electrode plate. ], 51... Positive electrode active material 2, 52... Support 3
...metal plate

Claims (4)

[Claims] (1) A long positive electrode plate in which a positive electrode active material is supported on a porous metal support and a long negative electrode plate made of a light metal are spirally wound with a separator interposed therebetween, and then placed in a non-aqueous solvent. In a cylindrical non-aqueous electrolyte battery that is housed in a battery container with an electrolytic solution containing dissolved electrolyte and sealed, the positive electrode active material at the winding end of the positive electrode plate is removed to expose the metal support. ,
A cylindrical non-aqueous electrolyte battery characterized in that a metal plate is fixed to the exposed metal support. (2) The metal plate is one metal plate bent into two,
2. The cylindrical non-aqueous electrolyte battery according to claim 1, wherein the bent portion covers a winding end of the positive electrode plate. (3) The cylindrical nonaqueous electrolyte battery according to claim 1 or 2, wherein the width of the metal plate is equal to or larger than the width of the positive electrode plate. (4) The cylindrical nonaqueous electrolyte battery according to claim 1, 2, or 3, wherein at least the corners of the metal plate in the winding end direction have a shape that is not sharp. .