JP3114466B2 - Non-aqueous electrolyte battery - 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 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 via a separator. The present invention relates to a nonaqueous electrolyte battery including a plate group.

[0002]

A negative electrode plate and manganese dioxide or the like of the strip of light metal such as lithium, such as the Related Art Japanese Utility Model 63-133065 JP an active material provided with a band-like positive electrode plate and the active material, through the separator Positive and negative plates are spirally wound
Non-aqueous electrolyte cell has a high energy density, suitable for high rate discharge, and are used in many applications because it has a feature that the self-discharge is small.

[0003] In recent years, as the applications of the spiral type nonaqueous electrolyte battery have expanded, not only use at high rate discharge but also use conditions at low rate discharge and use of a combination of both have diversified. 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 and positive electrode reaction area as shown in FIG. 4 so that a sufficient reaction efficiency can be obtained in 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 such a battery using a light metal, as the discharge proceeds, the light metal of the negative electrode plate 1 is consumed and becomes thinner. As shown in FIG. 5, when the negative electrode plate 11 is wound
At the position inward from the outer periphery of the positive electrode plate,
Dispose the negative electrode current collector 11a closer to the winding center than the winding end.
And the discharge efficiency is improved. However, low rate discharge
Due to the configuration of the electrode plate group, a portion 11f where the discharge reaction proceeds rapidly and a portion 11s where the discharge reaction proceeds slowly occur in the negative electrode plate 11.

As a result, the portion 11f where the discharge reaction proceeds rapidly
In this case, since the light metal of the negative electrode plate 11 is consumed quickly, the connection between the light metal of the negative electrode plate 11 and the negative electrode current collecting lead plate 11a is cut off at the end of the discharge, and the discharge reaction is interrupted. In the portion 11s where the discharge reaction proceeds slowly,
11c is a portion where the reaction proceeds particularly slowly,
Both sides are portions not facing the positive electrode plate 2 or portions facing the positive electrode current collecting lead plate 2a . In this part ,
The light metal of the negative electrode 11 is hardly consumed.

As a result, a portion 11s where the discharge reaction proceeds slowly
Although the current collecting lead plate 1 is in a dischargeable state,
The connection with 1a is disconnected, and the remaining light metal is not used as the negative electrode active material . For this reason, there was a problem that the discharge of the capacity originally possessed by the battery could not be performed, and the low-rate discharge characteristics at the end of discharge were poor.

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 held.

[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 plate having a separator. A non-aqueous electrolyte battery provided with a spiral electrode body wound around
Thus, the separator has a surface in contact with the positive electrode plate and the negative electrode plate .
It is characterized by having an insulating portion disposed along the longitudinal direction and at least in contact with the positive electrode current collector lead plate, and preventing transmission of ions .

[0010]

With this configuration, the non-aqueous electrolyte battery of the present invention has a continuous structure in which a part of the separator made of a microporous synthetic resin film is in contact with the positive and negative electrode current collector lead plates in the longitudinal direction of the surface in contact with the positive and negative electrode plates. Because at least one or more insulating portions are provided in the insulating portion, micropores of the separator are blocked in the insulating portion, and the permeation of ions is hindered. Is inhibited,
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 electrically connected until the discharge reaction is completely completed. State will be maintained. In addition, the same effect is exerted on the insulating portion in 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 one embodiment of the present invention will be described below in detail with reference to the drawings.

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

The negative electrode plate 1 is obtained by cutting lithium as a negative electrode active material into a certain 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 made of polypropylene insulation tape
Is provided. In FIG. 1, a positive electrode plate 2 having a positive electrode current collecting lead plate 2a wound opposite to the separator 3 is indicated by a dotted line, but a part of the insulating portion 3a is in contact with the positive electrode current collecting lead plate 2a. I have. The positive electrode plate 2 and the negative electrode plate 1 are spirally wound with a separator 3 interposed therebetween. Using this electrode group, a battery A of this example was produced.
For comparison, a comparative battery B was prepared 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 dimethoxyethane was used.

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

FIG. 2 shows that the battery A of the present embodiment did not show a sharp voltage drop at the end of discharge, whereas the comparative battery B showed a sharp voltage drop at point P at the end of discharge. Next, at point P in FIG. 2, that is, when the voltage of the comparative battery B sharply dropped, both batteries A and B 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 the present example, and FIG. 5 shows the negative electrode plate 11 of the battery B of the comparative example.
2 shows a cross section near the positive current collecting 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 to which the insulating tape is applied.
a of the negative electrode plate 1 in the portion facing the negative electrode current collector a, and the remaining portion of the lithium is separated from the part of the lithium that is being separated because the negative electrode current collector lead plate 1a is not attached and the negative electrode current collector lead plate 1a. Because of the continuous connection, the discharge reaction can be continued. However, the negative electrode plate 11 of the comparative battery B shown in FIG.
The portion of lithium to which a was not attached was separated from the negative electrode current collecting lead plate 11a. 3 and 5, the dotted lines show the initial state of the negative electrode plate.

The same effect as that of the battery A of the present embodiment was obtained when an insulating portion was provided on the surface of the separator in contact with the outermost peripheral portion of the positive electrode plate. 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 or the like in addition to the tape.

[0018]

As is apparent from the above description of the embodiment, according to the nonaqueous electrolyte battery of the present invention, the separator is formed along the longitudinal direction of the surface in contact with the positive and negative electrode plates, and at least > A part of the ion- permeable lead
By providing an insulating part that inhibits , in other words, an insulating part that has lost the separator function of the battery, the negative electrode active material that has conventionally been separated from the negative electrode current collector lead plate at the end of discharge,
Since it can be electrically connected to the negative electrode current collector lead plate, it can eliminate a sharp voltage drop at the end of discharge and sufficiently take out the discharge capacity of the negative electrode plate, and its practical value is extremely large.

[Brief description of the drawings]

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

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

FIG. 3 is a cross-sectional view showing the state of the 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 non-aqueous electrolyte battery;

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

[Explanation of symbols]

Reference Signs List 1 11 Negative electrode plate 1a 11a Negative electrode current collecting lead plate 1c 11c Part not facing positive electrode plate or part facing positive electrode current collecting lead plate 11f Part where discharge reaction proceeds fast 11s Part where discharge reaction proceeds slowly 2 Positive plate 2a Positive electrode current collecting lead plate 2b Outermost peripheral portion of positive electrode plate 3 Separator 3a Insulated part (no ion permeability)

Continuation of the front page (56) References JP-A 5-43465 (JP, U) JP-A 4-49454 (JP, U) (58) Fields surveyed (Int. Cl. ⁷ , DB name) H01M 2 / 18 H01M 6/16

Claims (2)

(57) [Claims] 1. A non-aqueous electrolyte battery comprising a spiral electrode body in which a strip-shaped negative electrode plate and a strip-shaped positive electrode plate using a light metal as an active material are wound with a separator interposed therebetween.
The heater extends in the longitudinal direction of the surface in contact with the positive electrode plate and the negative electrode plate, and
At least the positive current collector lead plate and is arranged to abut One
Characterized in that it has an insulating part that blocks the transmission of ions
Non-aqueous electrolyte battery to be. 2. The non-aqueous electrolyte battery according to claim 1, wherein the insulating portion is in contact with the outermost peripheral portion of the positive electrode plate.