JPH07142049A - Nonaqueous electrolyte battery - Google Patents

Abstract

PURPOSE:To eliminate the sudden voltage drop in the last stage of discharge, and take out sufficiently discharge capacity of a negative electrode plate by arranging an insulating part whose part comes into contact with a positive electrode current collecting lead plate in the lengthwise direction of a surface coming into contact with positive and negative electrode plates of a separator and from a battery separator function is eliminated. CONSTITUTION:A positive electrode plate 2 is cut off in a specific dimension by press- fitting paste obtained by mixing a conductive agent in manganese dioxide being a positive electrode active material to a current collecting body. On the other hand, a negative electrode plate 1 is formed by cutting off lithium being a negative electrode active material in a specific dimension. For example, an insulating part 3a by a polypropylene insulating tape having the width of about 1mm is arranged in the lengthwise direction of a separator 3 composed of a polypropylene microporous film having the thickness of 10 to 50mu. A part of this insulating part 3a comes into contact with a positive electrode current collecting lead plate 2a. These positive electrode plate 2 and negative electrode plate 1 are wound in a spiral shape through the separator 3, and a battery is formed. In this constitution, the sudden voltage drop in the last stage of discharge like an ordinary battery is eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spiral electrode in which a positive electrode plate having a positive electrode active material held on a current collector and a negative electrode plate made of a light metal such as lithium or a lithium alloy are wound around a separator. The present invention relates to a non-aqueous electrolyte battery including a plate group.

[0002]

2. Description of the Related Art Positive and negative electrode plates are provided with a strip-shaped negative electrode plate having a light metal such as lithium as an active material and a strip-shaped positive electrode plate having manganese dioxide as an active material as described in Japanese Utility Model Laid-Open No. 63-133065. The spirally wound non-aqueous electrolyte battery with a separator has a high energy density, is suitable for high rate discharge, and has a feature of low self-discharge, and thus is used in many applications. There is.

In recent years, as the applications of this spiral type non-aqueous electrolyte battery have expanded, the usage conditions have been diversified such as not only high-rate discharge but also low-rate discharge and combined use of the two. Even in such a case, it is necessary to obtain a large capacity (sufficient reaction efficiency).

[0004]

In the conventional spiral non-aqueous electrolyte battery, as shown in FIG. 4, the positive and negative electrode plates have a large reaction area so that sufficient reaction efficiency can be obtained at high rate discharge. The negative electrode current collecting lead plate 1a fixed to a part of the plate 1 was provided at a position slightly inward from the outermost peripheral portion 2b of the positive electrode plate 2.

In this case, in the low rate discharge, the light metal of the negative electrode plate 1 is consumed and becomes thinner as the discharge progresses. As shown in FIG. 5, in the structure of the electrode plate group, in the negative electrode plate 11, a portion 11f in which the discharge reaction proceeds rapidly and a portion 11 in which the discharge reaction proceeds slowly.
s occurs.

As a result, the portion 11f where the discharge reaction proceeds rapidly
However, since the light metal of the negative electrode plate 11 is consumed quickly, the light metal of the negative electrode plate 11 and the negative electrode current collecting lead plate 11a are disconnected at the end of the discharge, and the discharge reaction is interrupted. Reference numeral 11a denotes a negative electrode current collecting lead plate, and 11c denotes a portion not facing the positive electrode plate 2 or the positive electrode current collecting lead plate 2a.
The light metal of the negative electrode 11 is scarcely consumed in the portion opposed to.

As a result, since the light metal in the portion 11s where the discharge proceeds slowly is not used as the negative electrode active material, it is impossible to discharge the amount of the capacity originally possessed by the battery, and the low rate discharge characteristic at the end of discharge is inferior. Was.

The present invention solves such a problem, and an object of the present invention is to provide a non-aqueous electrolyte battery capable of sufficiently taking out the capacity of the negative electrode plate originally possessed.

[0009]

In order to solve this problem, a non-aqueous electrolyte battery of the present invention has a spiral electrode in which a strip negative electrode plate and a strip positive electrode plate are wound with a separator interposed therebetween. In the body, the separator is a positive electrode plate, a non-aqueous electrolyte battery provided with a non-ion-permeable insulating portion continuous in the longitudinal direction in contact with at least the positive electrode current collector lead plate on the surface in contact with the negative electrode plate. is there.

[0010]

With this structure, the non-aqueous electrolyte battery of the present invention has a structure in which a part of the separator made of a microporous synthetic resin film is in contact with the positive and negative electrode plates in the longitudinal direction of the surface in contact with the positive and negative electrode plates. Since at least one insulating portion is provided, the micropores of the separator are blocked at this insulating portion, and the permeation of ions is hindered. Is blocked,
Only the part of the negative electrode active material was consumed and remained, and as a result, all the active materials constituting the negative electrode plate and the negative electrode current collecting lead plate were electrically connected until the discharge reaction was completely completed. The state will be maintained. In addition, the same effect is exerted on the insulating portion that comes into contact with the outermost peripheral portion of the positive electrode plate.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A non-aqueous electrolyte battery according to an embodiment of the present invention will be described in detail below with reference to the drawings.

The positive electrode plate 2 is obtained by pressing a paste prepared by mixing manganese dioxide, which is a positive electrode active material, with a conductive agent onto a current collector and cutting the paste into a predetermined size.

The negative electrode plate 1 is made by cutting lithium, which is a negative electrode active material, into a predetermined size. As shown in FIG. 1, the separator 3 has a width of about 1 m / m in the longitudinal direction of the separator 3 made of a polypropylene microporous film having a thickness of 10 to 50 μm.
Insulation part 3a by m insulation tape made of polypropylene
Is provided. In FIG. 1, the positive electrode plate 2 having the positive electrode current collecting lead plate 2a wound so as to face the separator 3 is shown by a dotted line, but a part of the insulating portion 3a is in contact with the positive electrode current collecting lead plate 2a. There is. Then, the positive electrode plate 2 and the negative electrode plate 1 are spirally wound with the separator 3 in between. A battery A of this example was manufactured using this electrode plate group.
For comparison, Comparative Battery B was manufactured under the same conditions except that a separator having no insulating portion was used. As the electrolytic solution, a solution obtained by dissolving lithium trifluoromethanesulfonate in a mixed solvent of propylene carbonate and dimethyoxyethane was used.

FIG. 2 shows the discharge characteristics when the battery A of this example and the comparative battery B were discharged under a load of 200Ω at room temperature.

As shown in FIG. 2, in the battery A of this example, no sharp voltage drop was observed at the end of discharge, but in the comparative battery B, a sharp voltage drop was found at point P at the end of discharge. Next, at point P in FIG. 2, that is, at the time when the voltage of the comparative battery B drastically dropped, both batteries A and B were disassembled, and the state of the negative electrode plate of both batteries was examined. FIG. 3 shows the negative electrode plate 1 of the battery A of this example, and FIG. 5 shows the negative electrode plate 11 of the battery B of the comparative example.
3A and 3B show cross sections near the positive electrode current collector lead plate 2a and the outermost peripheral portion 2b in the longitudinal direction.

The negative electrode plate 1 of the battery A of this embodiment shown in FIG.
Is the insulating part 3 of the separator 3 with the insulating tape applied.
The lithium of the negative electrode plate 1 in the portion facing a is remaining, and the remaining lithium is separated from the negative electrode current collecting lead plate 1a in a portion where the negative electrode current collecting lead plate 1a is not attached. Since they are connected continuously, the discharge reaction is in a continuous state. However, in the negative electrode plate 11 of the comparative battery B shown in FIG.
The lithium in the portion where a was not attached was separated from the negative electrode current collector lead plate 11a. 3 and 5, the dotted line shows the initial state of the negative electrode plate.

Also, when the insulating portion is provided on the surface of the separator which is in contact with the outermost peripheral portion of the positive electrode plate, the same effect as that of the battery A of this embodiment was obtained. In addition, although an insulating tape made of polypropylene was used as the insulating material in this example, the same effect was obtained by printing the insulating material by a printing method other than the tape.

[0018]

As is apparent from the above description of the embodiments, according to the non-aqueous electrolyte battery of the present invention, a part of the positive electrode current collecting lead plate is formed in the longitudinal direction of the surface of the separator in contact with the positive and negative electrode plates. The negative electrode active material that has been separated from the conventional negative electrode current collector lead plate at the end of discharge by providing an insulating portion that does not have continuous ion permeability in at least one or more locations in contact with, in other words, eliminates the separator function of the battery, Since it can be electrically connected to the negative electrode current collecting lead plate, a rapid voltage drop at the end of discharge can be eliminated, and the discharge capacity of the negative electrode plate can be sufficiently taken out, and its practical value is extremely large.

[Brief description of drawings]

FIG. 1 is a front view showing a state in which a separator provided with an insulating portion made of an insulating tape in an embodiment of the present invention faces a positive electrode plate.

FIG. 2 is a diagram showing discharge characteristics of a battery of this example and a comparative battery.

FIG. 3 is a cross-sectional view showing the state of the negative electrode plate at the end of discharge of the battery of this example.

FIG. 4 is a top view of an electrode plate group formed by spirally winding a non-aqueous electrolyte battery.

FIG. 5 is a cross-sectional view showing the state of the negative electrode plate of the comparative battery at the end of discharge.

[Explanation of symbols]

1 11 Negative Electrode Plate 1a 11a Negative Electrode Current Collection Lead Plate 1c 11c Part Not Facing Positive Electrode Plate or Part Facing Positive Electrode Current Collection Lead Plate 11f Discharge Reaction Fast Part 11s Discharge Reaction Slow Part 2 Positive Plate 2a Positive electrode current collecting lead plate 2b Outermost part of positive electrode plate 3 Separator 3a Insulating part (without ion permeability)

Claims (2)

[Claims] 1. A spirally wound electrode body in which a strip-shaped negative electrode plate and a strip-shaped positive electrode plate are wound around a separator, wherein the separator is at least a positive electrode collector lead plate at a surface in contact with the positive electrode plate and the negative electrode plate. A non-aqueous electrolyte battery provided with a continuous insulating portion having no ion permeability in the longitudinal direction in contact therewith. 2. The non-aqueous electrolyte battery according to claim 1, wherein the insulating portion contacts the outermost peripheral portion of the positive electrode plate.