JPS6247954A - Manufacture of bobbin type nonaqueous electrolyte battery - Google Patents

Abstract

PURPOSE:To produce such a bobbin type nonaqueous electrolyte battery that is less in an internal short and excellent in capacity, by bending symmetrical end edges of a separator to the inner side of a negative pole metallic plate and holding both these end edges after being overlapped with each other, while holding the lower end edge, forming it into a cylindrical form, and inserting it into a cylindrical positive pole. CONSTITUTION:A separator 50 is opened wide and a negative electrode metallic plate 40 is superposed on it. Symmetrical end edges of the separator 50 are bent to the inner side, and each tip part of both these end edges is overlapped with each other and held fast with thermal deposition or a bonding agent. In addition, a double-folded part of the separator 50 projected to the lower end side are held fast with each other by means of the thermal deposition or the bonding agent. Next, The negative electrode 40 covered with the separator 50 is formed into cylindrical form, inserting it into a cylinder hole of a cylindrical positive electrode.

Description

Detailed Description of the Invention (Field of Industrial Application) This invention relates to a bobbin-type non-aqueous electrolyte having a structure in which a negative electrode made of a light metal such as lithium is loaded in a cylindrical positive (separator) via a separator. Relating to battery manufacturing methods.

(Prior Art) Conventionally, as a non-aqueous electrolyte battery, one having a bobbin-shaped structure as shown in FIG. 2 is known.

' In the battery shown in Figure IS2, a cylindrical negative electrode 14. Separator 169
A power generation element consisting of a cylindrical positive electrode 18 is arranged coaxially in this order from the center, and a non-aqueous electrolyte 22 is poured inside.

The open end of the battery case 12 has a negative 4t formed in a dish shape.
It is sealed by the i terminal plate 26, a thin metal plate 30 applied to the inside of the negative terminal plate 26, and a synthetic resin gasket 28 fitted around these. Note that the negative vent plate 26 is provided with a cutting blade piece 26a that is cut and raised with a gas center hole 261], and the tip of this cutting blade piece 26a protrudes into the center of the thin metal plate 30. ing.

This 4''1 is a rupture prevention structure that is activated when the internal gas pressure of the battery increases abnormally.

Since the negative electrode 4 is a cylindrical metal plate made of lithium or the like, a current collector 24 and a lead plate 32 are bonded to the inner surface thereof. The lead plate 32 electrically connects the negative electrode 14 and the negative terminal plate 26.

The separator 1G is made of a nonwoven fabric made of polypropylene or the like, and is wrapped around the outer periphery of the cylindrical negative electrode 14 one or more times.

This type of battery is manufactured by first loading a cylindrical positive electrode 18 inside a battery case 12, and then loading a cylindrical negative electrode 14 with a separator 16 wound around its outer periphery into a cylindrical hole of the positive electrode 18. As shown in the figure, the width of the separator 1G is sufficiently larger than the height of the cylindrical negative electrode 14, and the separator 16 largely protrudes above and below the negative electrode 14. This is negative electrode 1
This is to reliably isolate the positive electrode 4 and the positive electrode 18 to prevent internal short circuits.

Conventionally, a separator 16 is wrapped around the outer periphery of a cylindrical negative electrode 14, and the separator 16 protruding from the lower end is folded inward as shown by reference numeral 16a in the figure. By folding the lower edge 16a of the separator 16 inward and wrapping the lower edge of the negative 8i14 in this way, the separator 1
6, the lower end of the negative electrode 14 is aligned with the battery case 1.
2 and can reliably prevent internal short circuits.

(Problems to be Solved by the Invention) In the above-mentioned conventional technology, the work of folding the lower edge 16a inward in an orderly manner after wrapping the separator 16 around the cylindrical negative electrode 14 is troublesome, which is a factor that hinders productivity improvement. It was one of the

'Especially when the separator 16 is allowed to protrude significantly from the lower end of the negative electrode 14, it becomes extremely troublesome to neatly fold the lower end 16a inward. Therefore, the protrusion of the separator 16 cannot be made so large.

If the separator 16 does not protrude too much and its lower edge 16a is not properly folded into the inside of the negative electrode 14, when inserting the negative electrode 14 and separator 16 into the cylindrical hole of the positive electrode 18. , separator 16
The lower end edge 16a tends to slide up due to the upward tensile force acting on the negative electrode 140, and the lower end portion of the negative electrode 140 may be exposed. This tends to cause internal short circuits, leading to the production of defective products.

Due to the above, some attempts have been made in the past to form a separator into a bag shape with a bottom, insert a cylindrical negative electrode into the bag, and then insert both into the cylindrical i'E electrode. It is being

However, in this structure and manufacturing method, the number of manufacturing steps is increased because the separator is formed into a bag shape. Also, insert the negative electrode into the separator, insert the separator J5 into the positive electrode and the negative (tree 1;
A! The J-beam process becomes troublesome. In addition, in order to improve the close contact between the negative electrode and the separator, the size of the bag-shaped separator was made smaller, and J-3
＜, it is difficult to insert the negative electrode, and the separator is likely to break during insertion.

If the adhesion between the negative electrode and the separator is not good, the electrical characteristics will deteriorate.

This invention was made in view of the above-mentioned conventional problems, and its purpose is to improve the workability of assembling the negative electrode and separator parts in a bobbin type non-aqueous electrolyte battery having the basic structure as described above. Moreover, it is an object of the present invention to provide a manufacturing method that prevents internal short circuits from occurring due to improper attachment of separators.

(Means for Solving the Problems) Therefore, in the present invention, a large square separator is superimposed on the outer surface of a square negative electrode metal plate, and the left and right edges of the separator are connected to the inner surface of the negative electrode metal plate. At the same time, the lower edges of the separators that protrude from the lower end side of the negative electrode metal plate and overlap each other are attached, and then the negative electrode metal wrapped with the separator is attached. The plate was formed into a cylindrical shape with the inner surface facing inside, and this cylindrical object was inserted into the cylindrical body (water).

(Function) The negative electrode metal plate is completely wrapped in the separator,
Since it is formed into a cylindrical shape in this state, the adhesion between the separator and the negative electrode is good, and a part of the separator does not shift from the f1 pole (Example) Figure 1 (Δ) (B) and (C) are process diagrams showing examples of the fruiting colors of the method for manufacturing a bobbin type non-aqueous separator cell according to the present invention.

In FIG. 1, numeral 33 indicates a rectangular negative electrode metal plate, and 50 indicates a rectangular separator having dimensions sufficiently larger than the negative electrode metal plate 40. In FIG. The negative electrode metal plate 40 is made of a light metal such as lithium, and is later wound into a cylindrical shape, with a 1-node plate 41 and a current collector 42 being joined (1) to the inner surface of the negative electrode metal plate 40 .

The separator 50 is made of a polypropylene non-woven fabric, etc. First, as shown in FIG. (Also, place the outer surface side of the separator 50 on the separator 50.)
In the stacked state, the cenometer 5 protrudes from each of the four sides of the negative electrode metal plate 40 by a predetermined distance. In particular, the length of the separator 50 is more than twice the length of the negative electrode metal plate 40.

Next, as shown in FIG. 1(B), the left and right edges of the separator 50 that protrude to the left and right of the negative metal plate 4O are bent toward the inner surface of the negative metal plate 40, and the tip portions of both edges are bent. overlap each other.

Then, both ends of the separator 50 whose widths are joined together are fixed by heat sealing or adhesive. The X mark with the symbol @51 in the figure indicates a fixed portion.

When the left and right edges of the separator 50 are folded inward as described above, the separators 50 that have been protruding above and below the negative electrode metal plate are also stacked in two sheets. Among these upper and lower protruding parts, the two overlapping parts of the separator 50 protruding toward the lower end are fixed to each other by heat sealing or adhesive. The X mark with the reference numeral 52 in the figure indicates the fixed portion.

Through the above steps, the negative electrode metal plate 40 is completely wrapped in the separator 50. Next, the cylindrical negative electrode 40 covered with the separator 50 is formed into a cylindrical shape as shown in FIG. 1(C). For example, a cylindrical winding core is applied to the state shown in FIG. 1(B), and the winding core is deformed so that the negative electrode metal plate 40 covered with the separator 50 is brought into close contact with the winding core.

Through the above steps, a cylindrical negative electrode covered with a separator is completed. On the other hand, although not shown, a cylindrical positive electrode is loaded in a metal case as in the conventional case, and the cylindrical object shown in FIG. 1(C) is inserted into the cylindrical hole of the cylindrical positive electrode. .

The bobbin type non-aqueous electrolyte battery is assembled using the same process as before.

In addition, as the separator 50 in the present invention, a material obtained by stacking thin non-woven fabrics or the like as many times as necessary may be used.

(Effects of the Invention) As explained in detail above, according to the manufacturing method of the present invention, the work of wrapping the negative metal plate with the separator is very simple, and the negative metal plate is completely covered with the separator. , there are no exposed or easily exposed areas. Furthermore, since the separator and the negative electrode metal plate are integrally formed into a cylindrical shape, the working process is simplified. Moreover, the adhesion between the separator and the negative electrode becomes better. In other words, a bobbin type non-aqueous electrolyte battery with excellent performance and less internal short circuits can be manufactured with a high yield using a rational manufacturing method that is easier to work with than conventional methods.

[Brief explanation of drawings]

Fig. 1 (△), (B), and (C) are perspective views showing the main steps of the manufacturing method according to an embodiment of the present invention, and Fig. 2 is a typical conventional structure of a bobbin type non-aqueous electrolyte battery. It is a sectional view showing old. 12... Battery case 14... Cylindrical negative electrode 16... Separator 18...
・Cylindrical positive electrode 40...Negative electrode metal plate 41...
... Lead plate 42 ... Current collector 50
...Separator 51, 52...Separator 50 fixed portion Patent applicant Fuji Electrochemical Co., Ltd. Agent
Patent Attorney - Kensuke Shiro Figure 1 (B) Figure 1 (C)

Claims (1)

[Claims] (1) A method for manufacturing a bobbin-type non-aqueous electrolyte battery in which a cylindrical negative electrode is arranged in a cylindrical hole of a cylindrical positive electrode with a separator interposed therein, in which a larger Square-shaped separators are overlapped, and the left and right edges of the separators are bent toward the inner surface of the negative electrode metal plate, and both edges are overlapped and fixed. The lower edge of the separator is fixed, and then the negative electrode metal plate wrapped with the separator is formed into a cylindrical shape with the inner surface facing inside, and this cylindrical object is inserted into the cylindrical positive electrode. A method for manufacturing a bobbin type non-aqueous electrolyte battery characterized by: