JPS6235460A - Negative electrode plate of cylindrical nonaqueous electrolyte battery - Google Patents

Abstract

PURPOSE:To improve discharge characteristic by providing a metal thin film forming the recessed and projected portions at the end part of negative electrode plate. CONSTITUTION:A metal thin plate 2 which will be used as the collector forms the recessed and projected portions with the embossing finish. This negative plate 3 is wound like an eddy with a separator to form a electrode group. In this case, a metal thin plate 2 is located at the outside of metal lithium 1, exposed to the outer most circumference of the electrode group, the outer most circumference of electrode group is desirably covered and the projected part is located outside. Thereby, the electrode group is accurately inserted into the battery case, electrical contact with battery case is improved, winding of electrode group is not loosened. Thereby, internal resistance of battery may be reduced and application coefficiency of active substance may also be improved and the discharge characteristic may also be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement of a negative electrode plate of a spirally folded electrode group of a cylindrical non-aqueous electrolyte battery.

[Conventional technology]

Conventionally, in this type of battery, a separator is interposed between long positive and negative electrode plates, and the electrodes are wound in a C spiral shape, and the current collector of one electrode plate is exposed at the outermost periphery of the wound electrode group. , battery container 1; inserting (from the second, exposed current collector and 4
It was brought into contact with the inner wall of the pond container to establish electrical conduction.

However, when inserting the electrode group into the battery container (= when the two touch each other, it becomes difficult and impossible to insert the electrode group.) If the electrode group is inserted, the separator may fold back, the electrode active material may be missing, or the electrode group may not be inserted near the outer periphery of the electrode group, resulting in damage to the electrode group. Therefore, in general, the outside diameter of the magnetic pole group is made smaller than the inside diameter of the battery container by about one inch, so that the two do not touch each other when inserted. The contact between the body and the inner wall of the battery container becomes insufficient and unstable, and the winding of the electrode group becomes loose, resulting in poor adhesion between the electrodes, which increases the internal resistance of the battery and reduces the utilization rate of the active material. This caused a decline in the
As described in Japanese Patent No. 772, a method has been proposed in which a wound electrode group is housed in a spring that can be actuated laterally and then inserted into a battery container.

[Problem that the invention seeks to solve]

However, although the above method provides good contact between the spring and the battery container, the winding of the electrode group becomes loose, resulting in poor adhesion between the electrodes, resulting in the same problems as described above. In addition, since springs are expensive, the cost increases, and the space where the springs are located is wasted, so
Volumetric efficiency also deteriorated.

On the other hand, Japanese Utility Model Application Publication No. 58-134863 discloses a method in which a thin metal plate is placed at the end of the winding of the current collector of the magnetic pole, and this thin metal plate covers the outermost periphery of the sulfuric pole group and contacts the inner wall of the battery container. is proposed. This method increases the contact area with the battery container, so the conductivity (although improved in two ways)
There was a problem that the winding of the electrode group could not be avoided.

The present invention provides a cylindrical nonaqueous electrolyte battery with excellent discharge performance without reducing volumetric efficiency by improving the shape of the negative electrode current collector.

[Means for Solving the Problems] The present invention provides a long separator between a long positive electrode plate and a negative electrode plate, and the negative electrode plate is placed on the outermost periphery of the electrolyte battery. A negative electrode plate having a thin metal plate with an uneven portion attached to the end of the winding of the plate is used in a cylindrical non-aqueous electrolyte battery.

[Effect]

By using the negative electrode plate of the cylindrical non-aqueous electrolyte battery of the present invention, when the electrode group is inserted into the battery container, the apex of the convex portion formed on the negative electrode current collector comes into contact with the battery container, so that the resistance at the time of insertion is is small, and the convex part has spring properties in the lateral direction, so there is no deformation of the two-spiral electrode group during insertion. By covering, weak members such as electrode plates and separators can be completely protected.For this reason, the inside diameter of the battery container is C; The diameter can be made slightly smaller and the outer diameter of the convex part slightly larger, increasing the volumetric efficiency.In addition, by increasing the volumetric efficiency, the contact pressure of the convex part of the metal sheet increases, resulting in good electrical contact. Therefore, the internal resistance of the battery becomes smaller.

Further, the winding of the wound electrode group does not become loose, and the discharge performance can also be improved.

〔Example〕

The negative electrode plate of the cylindrical non-aqueous electrolyte battery of the present invention will be explained with reference to the drawings. FIG. 1 shows an elongated negative electrode plate of the present invention, where 1 is a metal lithium plate and 2 is a metal thin plate serving as a current collector.

This thin metal plate 2 may have uneven parts formed by embossing, or may have an inverted V-shaped C shape as shown in FIG. Two incisions are made and the tip rises to form an uneven surface. This negative electrode plate 3 is wound together with a positive electrode plate and a separator (in two spirals to form an electrode group. At this time, the metal thin plate 2
is located outside the metal lithium 1, and the outermost periphery of the electrode group (=
It is exposed, preferably covers the outermost periphery of the magnetic pole group, and is bent so that the convex portion faces outward. In particular, the inverted V-shaped notch as shown in Figure 2 (a) should be placed on the outside (in the case of a raised protrusion, the direction without the notch, that is, the
'Force direction is the direction of insertion into the battery container. The metal thin plate covering the outermost periphery of the spiral electrode group is pressed into close contact with the metal lithium plate 1, and the outer diameter of the recesses in the metal thin plate covering the electrode plate group is the same as that of the battery container. It is wound so that the outer diameter of the convex part is slightly larger than the inner diameter.

〔Effect of the invention〕

As described above, by attaching a thin metal plate with a concave and convex portion to the end of the winding of the negative electrode plate of the spirally wound electrode group (two turns), the electrode group can be inserted into the battery container accurately (two times). As a result, electrical contact with the battery container is improved, the winding of the electrode group is prevented from loosening, the internal resistance of the battery can be reduced, the utilization rate of materials can be improved, and the discharge performance can be improved.

[Brief explanation of the drawing]

Figure 1 is a front view of an embodiment of the negative electrode plate of the cylindrical non-aqueous electrolyte battery of the present invention, and Figures 1 and 12 show the negative electrode plate to attached thin metal plate. -x' line sectional view. l...Metal lithium plate 2...Metal thin plate 3...Negative electrode plate

Claims (4)

[Claims] (1) In a cylindrical non-aqueous electrolyte battery that is spirally wound with a separator interposed between long positive and negative electrode plates and filled in a battery container with electrolyte, at the end of the winding of the negative electrode plate, A negative electrode plate for a cylindrical non-aqueous electrolyte battery, characterized in that a thin metal plate having an uneven portion is attached thereto. (2) The negative electrode plate for a cylindrical nonaqueous electrolyte battery according to claim 1, wherein the uneven portion of the thin metal plate is formed by embossing and is convex toward the outside. (3) The uneven portion of the thin metal plate is cut in an inverted V shape, leaving at least the lower side, and the cut protrudes outward. Negative electrode plate of cylindrical non-aqueous electrolyte battery. (4) Claims 1 and 2, characterized in that the thin metal plate completely covers the outermost periphery of the spiral electrode group.
A negative electrode plate for a cylindrical non-aqueous electrolyte battery according to item 1 or 3.