JP3082551B2 - Non-aqueous electrolyte battery and its manufacturing method - Google Patents

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 in which a positive electrode active material is held on a current collector and a negative electrode plate made of a light metal such as lithium or a lithium alloy are wound via a separator. The present invention relates to a nonaqueous electrolyte battery including a plate group.

[0002]

2. Description of the Related Art Conventionally, a strip-shaped negative electrode plate using a light metal such as lithium as an active material and a strip-shaped positive electrode plate using manganese dioxide or the like as an active material, as described in Japanese Utility Model Application Laid-Open No. 63-133305, are provided. The non-aqueous electrolyte battery, in which the negative electrode plate is spirally wound with a separator interposed therebetween, has the features of high energy density, suitable for high-rate discharge, and low self-discharge. Have been.

However, in recent years, as the applications of the spiral type non-aqueous electrolyte battery have expanded, not only high-rate discharge but also low-rate discharge and a combination of both have been used. Even in such a case, it is necessary to obtain a large capacity (sufficient reaction efficiency).

[0004]

The conventional spiral type non-aqueous electrolyte battery has a large negative electrode plate reaction area, as shown in FIG. 4, so that a sufficient reaction efficiency can be obtained in efficient discharge. Negative electrode current collecting lead plate 1a fixed to a part of 1
At a position slightly inward from the outermost peripheral portion 2 e of the positive electrode, which is the terminal end of the positive electrode plate 2.

In this case, in the low-rate discharge, as the discharge proceeds, the light metal of the negative electrode plate 1 is consumed and becomes thinner. As shown in FIG. 5, at this time, due to the configuration of the electrode plate group, a portion 11f in which the discharge reaction proceeds rapidly and a portion 11s in which the discharge reaction proceeds slowly occur in the negative electrode plate 1.

As a result, the portion 11f where the discharge reaction proceeds rapidly
In this case, the consumption of the light metal of the negative electrode plate 11 is accelerated, so that at the end of the discharge, the connection of the light metal of the negative electrode plate 11 to the negative electrode current collecting lead plate 11a is cut off, and the discharge reaction is interrupted. 11a is a negative electrode current collecting lead plate, 11c is a portion not facing the positive electrode plate 2 or a positive electrode current collecting lead plate 2a.
The light metal of the negative electrode 11 is hardly 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, the discharge of the capacity originally possessed by the battery cannot be performed, and the low rate discharge characteristic at the end of discharge is inferior. Was.

An object of the present invention is to solve such problems and to provide a nonaqueous electrolyte battery capable of sufficiently taking out the capacity of the originally held negative electrode plate and a method of manufacturing the same.

[0009]

In order to solve this problem, a non-aqueous electrolyte battery according to the present invention comprises a strip-shaped negative electrode plate using a light metal as an active material and a strip-shaped positive electrode containing manganese dioxide as a main active material. The plate and the spiral electrode body wound around a separator, the positive electrode plate, the negative electrode plate, low activity of manganese dioxide continuous at least at one or more locations in the longitudinal direction of the surface in contact with the separator A non-aqueous electrolyte battery provided with a strip portion and a method for manufacturing the same.

[0010]

According to this structure, the nonaqueous electrolyte battery of the present invention has an activity of continuous manganese dioxide in which a portion of the positive electrode plate contacts the negative electrode plate and the separator in the longitudinal direction, and a part thereof contacts the positive electrode current collecting lead plate. Since at least one or more low-band portions are provided, the reaction of the portions of the negative electrode plate and the positive electrode plate facing each other via the band-like portions is inhibited, and the negative electrode active material remains without being consumed only in that portion. As a result, all the active materials constituting the negative electrode plate and the negative electrode current collecting lead plate are kept electrically connected until the discharge reaction is completely completed. In addition, since the low-activity portion of manganese dioxide is formed by laser light irradiation, the activity can be extremely efficiently reduced only in a necessary portion, and the loss of capacity can be minimized.

[0011]

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

FIG. 6 shows the processing steps of the positive electrode plate used in the battery of the present invention. For the positive electrode plate 2, 8 parts by weight of a conductive agent and 2 parts by weight of a binder were mixed with 90 parts by weight of manganese dioxide as a positive electrode main active material. The paste is pressed into a current collector and cut into a certain size, and is irradiated with a laser beam 4 in the longitudinal direction and locally heated to 450 ° C. or more, preferably 500 to 600 ° C., to thereby reduce the activity of Mn. _{A 2O3} strip 2b is provided. In FIG. 6, reference numeral 5 denotes a laser processing nozzle, and reference numeral 6 denotes an assist gas supply pipe.

The negative electrode plate is obtained by cutting lithium as a negative electrode active material into a certain size. Although FIG. 1 shows the positive electrode plate 2 having the positive current collector lead plate 2a which is wound by facing the negative electrode plate 1, a portion of the strip portion 2b of the low Mn _2O3-activity is the positive current collector lead It is in contact with the plate 2a. Then, the positive electrode plate 2 and the negative electrode plate 1 are spirally wound via a separator 3 made of a microporous polypropylene film having a thickness of 25 μm. Using this electrode group, a battery A of this example was produced. As the electrolytic solution, a solution prepared by dissolving lithium trifluoromethanesulfonate at a concentration of M / 1 in an equal volume mixed solvent of propylene carbonate and dimethoxyethane was used.

FIG. 2 shows that the batteries A to D of this embodiment and the comparative battery E (without laser beam irradiation) were kept at room temperature for 20 minutes.
It shows the discharge characteristics when discharging with a load of 0Ω.

FIG. 2 shows that in the batteries A to D of this embodiment, no sharp voltage drop was observed at the end of discharge.
In the comparative battery E, a sharp voltage drop was observed at the point P at the end of discharging. Next, at point P in FIG. 2, that is, at the time when the voltage of the comparative battery E suddenly dropped, the batteries A and E were disassembled, respectively, and the state of the negative electrode plates of both batteries was examined.

FIG. 3 shows the negative electrode plate 1 of the battery A of this embodiment, and FIG.
Shows a cross section near the longitudinal positive electrode current collecting lead plate 2a and the outermost peripheral portion 2e of the negative electrode plate 11 of the battery E of the comparative example.

The negative electrode plate 1 of the battery A of this embodiment shown in FIG.
Is the lithium 1 in the portion opposed to the low-activity band-like portion.
b, and the remaining part of the lithium is continuously connected to the part of the lithium that is being separated without the negative electrode current collecting lead plate 1a being attached to the negative electrode current collecting lead plate 1a. Is in a continuous state.
However, in the negative electrode plate 11 of the comparative battery E shown in FIG. 5, the portion of the lithium to which the negative electrode current collecting lead plate 11a was not attached was separated from the negative electrode current collecting lead plate 11a. still,
3 and 5, the dotted lines show the initial state of the negative electrode plate.
Further, the surface temperature of manganese dioxide by laser light irradiation in this example is 450 to 500 ° C. for A, and 500 to 55 B for B.
The test was performed at 0 ° C, C was set at 550 to 600 ° C, and D was set at 600 to 650 ° C. The laser apparatus used was a carbon dioxide laser, and non-oxidizing high-purity nitrogen gas was used as an assist gas. Output 5W
However, the temperature was raised to the above-mentioned temperature by changing the processing speed (mm / sec). The output of the laser was 5 W in the embodiment, but the above processing can be performed without any problem if the output is 3 to 8 W. If it is 8 W or more, the conductive agent in the positive electrode may ignite, and if it is 3 W or less, the above temperature condition cannot be achieved.

[0018]

As is clear from the above description of the embodiment,
According to the non-aqueous electrolyte battery of the present invention, the negative electrode plate of the positive electrode plate, in the longitudinal direction of the surface in contact with the separator, a part of the continuous low manganese dioxide band-shaped portion in contact with the positive electrode current collecting lead plate is formed. By providing at least one place,
The negative electrode active material, which had been separated from the negative electrode current collector lead plate at the end of discharge, can be electrically connected to the negative electrode current collector lead plate, eliminating the sudden voltage drop at the end of discharge and discharging the negative electrode plate. The capacity can be taken out sufficiently.
In addition, since heat treatment can be locally performed by using laser light, unnecessary portions are not heat-treated, so that loss of capacity can be minimized.

In this embodiment, an example of a carbon dioxide gas laser is shown. However, the inventor has confirmed that a similar effect can be obtained by setting the output of a YAG laser to 10 to 30 W from the output characteristics. As described above, the practical value is extremely large.

[Brief description of the drawings]

FIG. 1 is a front view of a positive electrode plate provided with a band portion having low activity in one embodiment of the present invention.

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

FIG. 3 is a cross-sectional view of the vicinity of a negative electrode current collecting lead plate in a longitudinal direction showing a state of a negative electrode plate at the end of discharging of the battery of the present embodiment.

FIG. 4 is a top view of a spirally wound electrode plate group of a nonaqueous electrolyte battery.

FIG. 5 is a cross-sectional view of the vicinity of a negative electrode current collecting lead plate in a longitudinal direction showing a state of the negative electrode plate at the end of discharging of a comparative battery.

FIG. 6 is a process diagram of a positive electrode plate according to one embodiment of the present invention.

[Explanation of symbols]

 1, 11 Negative electrode plate 1a, 11a Negative electrode current collecting lead plate 2 Positive electrode plate 2a Positive electrode current collecting lead plate 2b Low activity manganese dioxide strip 2e Positive electrode outermost peripheral part 3 Separator 4 Laser 5 Laser processing nozzle 6 Assist gas supply pipe

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01M 4/06-4/08 H01M 6/16

Claims (5)

(57) [Claims] A strip-shaped negative electrode plate using a light metal as an active material;
In a spiral electrode body in which a band-shaped positive electrode plate containing manganese dioxide as a main active material is wound via a separator, the positive electrode plate is at least one position in the longitudinal direction of a surface in contact with the negative electrode plate and the separator. A non-aqueous electrolyte battery provided with a continuous low-activity manganese dioxide strip as described above. 2. The non-aqueous electrolyte battery according to claim 1, wherein the positive electrode current collecting lead plate fixed to a part of the positive electrode plate is in contact with a band-like portion having low manganese dioxide activity. 3. A method for producing a non-aqueous electrolyte battery, comprising irradiating a laser beam to a surface of a positive electrode plate as a method for providing a band-shaped portion having low activity of manganese dioxide. 4. The method for producing a non-aqueous electrolyte battery according to claim 3, wherein the laser beam irradiation is a carbon dioxide gas laser or YAG. 5. The method for producing a non-aqueous electrolyte battery according to claim 4, wherein the laser light output is 3 to 8 W for a carbon dioxide gas laser and 10 to 30 W for a YAG laser.