JP2008097964A - Nonaqueous electrolyte solution battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte solution battery with improved productivity through prevention of damage of a cathode due to winding, in winding a cathode plate with high cathode active material density. <P>SOLUTION: In the nonaqueous electrolyte solution battery made by housing an electrode plate group structured by winding an anode plate and a cathode plate with an electrode mixture coated on either face of a collector through a separator, and electrolyte solution in a case, the cathode is provided with a coated part covered with the electrode mixture and a non-coated part without coating of the electrode mixture and with the collector exposed. A lead for current collection is connected to the non-coated part, and an insulation tape is arranged at an interface part of the coated part and the non-coated part, with the insulation tape having a paste agent face existing only at one side end of the base material face, and pasted only to the non-coated part. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a non-aqueous electrolyte battery, and more particularly to a shape of an insulating tape and a method for attaching the insulating tape.

  In the conventional non-aqueous electrolyte battery, the risk of heat generation due to micro short-circuits increases due to the increase in capacity, and the positive electrode active material density increases due to the increase in capacity, so that the positive electrode plate becomes hard and being wound. The reliability and productivity were reduced due to damage.

  Therefore, various countermeasures against micro short-circuits and damage during winding have been proposed.

For example, in a structure in which the mixture is not coated on the current collector of the positive electrode plate and faces the negative electrode mixture or the negative electrode core material via the separator, it faces the negative electrode mixture or the negative electrode core material. It has been proposed to protect the current collector by sticking an insulating tape on the current collector of the positive electrode plate. (See Patent Document 1 or Patent Document 2)
Alternatively, as a countermeasure against damage during winding, an approach has been made to prevent breakage during winding by providing a spot-like recess in the bent portion of the positive electrode plate. (See Patent Document 3)
JP 2006-179370 A Japanese Patent Laid-Open No. 2004-247064 JP 2003-346883 A

  However, in the conventional method of protecting with an insulating tape, for example, by bending and winding the positive electrode active material layer at the winding leading portion, the mixture inside the winding at the winding leading portion is compressed. By fixing the stress applied to the agent on the adhesive surface of the insulating tape, there is a problem that the total stress may concentrate on the current collector side and break.

  In addition, even in the method using spotted recesses, there is an easily damaged portion at the boundary between the mixture surface and the current collector surface. It was not possible to reduce the productivity of high-capacity products.

  An object of the present invention is to provide a non-aqueous electrolyte battery in which the positive electrode plate having a high density of the positive electrode active material is wound to prevent the positive electrode from being damaged by winding and the productivity is improved.

  In order to solve these conventional problems, the nonaqueous electrolyte battery of the present invention is an electrode in which a negative electrode plate coated with an electrode mixture on both sides of a current collector and a positive electrode plate are wound via a separator. In a non-aqueous electrolyte battery prepared by housing a plate group and an electrolyte in a case, the positive electrode has no coating part covered with the electrode mixture and no coating of the electrode mixture, and a current collector The uncoated portion is exposed, a lead for current collection is connected to the uncoated portion, and an insulating tape is arranged at the boundary between the coated portion and the uncoated portion, and the insulating tape The paste surface is present only at one end of the substrate surface, and the paste surface is attached only to the uncoated portion.

  With this configuration, it is possible to prevent the positive electrode plate from being damaged by the mixture compressive stress, so that productivity can be improved.

  At this time, the shape of the insulating tape is composed of a base material surface and a paste surface, the paste surface is disposed only on one end of the base material surface, and the portion covered with the mixture of the positive electrode plate and the current collector It is preferable that a paste surface is provided on the core part of the boundary part on the inner side of the winding, and a base material surface is provided on the mixture part, at least at the winding head side of the boundary part where the body is exposed.

  By using the insulating tape of the present invention, the positive electrode plate active material layer at the winding head portion is bent and wound, so that the mixture inside the winding portion at the winding head portion is compressed and applied to the mixture at that time By fixing the stress with the tape, the total stress was concentrated on the current collector side and it was damaged, but by not placing the adhesive material on the mixture part, the mixture collapsed due to the compressive stress of the mixture, and the tape direction Since the stress is dispersed, damage can be prevented and the productivity of high capacity products can be improved.

  According to the present invention, a non-aqueous electrolyte battery with improved productivity can be provided without causing damage to the positive electrode plate during winding of the positive electrode plate having a high positive electrode active material density.

  An insulating tape according to the present invention is shown in FIGS. 1 (a) and 1 (b), and a conventional insulating tape is shown in FIGS. 5 (a) and 5 (b). FIG. 1A is a front view, and FIG. 1B is a side view thereof. 1 (a) and 1 (b), the shape of the insulating tape is composed of a base material surface 1 and a paste surface 2, and is composed of a portion having the paste surface and a portion consisting only of the base material surface.

  FIGS. 2A and 2B show the state of the winding leading portion where the tape is attached to the positive electrode plate. FIG. 2A is a front view, and FIG. 2B is a side view thereof. The current collector 3 is provided with a current collecting lead 4 and a tape glue surface 2. And only the base material surface 1 is arranged on the mixture surface 5, and the tape glue surface 2 is not arranged. As shown in FIGS. 2 (a) and 2 (b), in the present embodiment, the tape of the present invention is arranged on the inner surface with respect to the winding direction 6, and the conventional tape is arranged on the outer surface. is doing.

  FIG. 3A shows a cross-sectional view when the positive electrode plate is wound. The positive electrode plate is wound along the R shape of the winding core. At that time, a compressive stress 7 is applied to the mixture inside the winding. A tensile stress 8 is applied to the current collector. The compressive stress 7 increases as the R shape decreases, that is, the compressive stress increases as the leading portion of the winding becomes. And when the adhesive surface of the insulating tape covers the mixture surface of the inner surface of the winding leading portion as shown in FIG. 3B, the mixture is fixed, so the mixture cannot be compressed, The load stress 9 is applied to the current collector. Therefore, if the breaking limit of the current collector is exceeded with respect to load stress and tensile stress, the positive electrode plate is damaged. Therefore, if the paste surface is not arranged on the mixture as shown in FIG. 3C, the mixture collapses in the direction of 10 due to the compressive stress 7 generated during winding. By breaking in this direction, the load stress 9 can be reduced, so that the current collector can be prevented from being damaged. Therefore, the productivity can be improved in winding a positive electrode having a high density and a high thickness as in a high-capacity product.

In this example, KAW-4BTQH-M manufactured by Minato Corporation was used as the winding machine. As shown in FIG. 4, the winding core uses a winding core 11 of φ3.5, is mainly composed of LiCoO ₂ , and the active material density is 3200 Kg / m ³ , 3400 Kg / m ³ , 3500 Kg / m ³ , The current collector used was aluminum (JIS product number, A3003), a thickness of 15 μm, a positive electrode plate having a mixture part thickness of 80 μm on one side was used, and a negative electrode plate mainly composed of carbon was used as the negative electrode plate. . The separator used was a polyethylene separator manufactured by Asahi Kasei Corporation. In the present invention, the insulating tape is a 16 mm wide tape, and the width of the adhesive surface is 10 mm. Moreover, the conventional tape set the tape width to 16 mm, and set the covering margin to the mixture surface to 3 mm. Then, 1000 cells are wound for each positive electrode plate, and the number of breakage occurrences and the operation rate at that time are shown in Table 1.

（表１）より本発明の絶縁テープを使用することにより、捲回における集電体破損による正極板の破損を防ぐことができ、生産性を向上できることを確認した。

From Table 1, it was confirmed that by using the insulating tape of the present invention, it was possible to prevent the positive electrode plate from being damaged due to the current collector breakage during winding, and to improve productivity.

  The reason for this is that the tape adhesive surface was not placed on the inner surface of the winding material at the beginning of the winding, so that the mixture collapsed due to the compressive stress generated by winding and the load stress on the current collector was reduced. As a result, no damage was caused even when a high-density positive electrode plate was used.

  The cylindrical non-aqueous electrolyte battery manufactured by the method for manufacturing a cylindrical non-aqueous electrolyte battery with good productivity of the present invention is useful for a power source of an inexpensive consumer portable device.

(A) Schematic front view of the insulating tape of the present invention, (b) Schematic side view of the insulating tape of the present invention (A) A schematic front view of a positive electrode plate to which the insulating tape of the present invention is attached, (b) a schematic side view of FIG. (A) Schematic diagram of stress generated when winding a positive electrode plate, (b) Schematic diagram of stress generated when winding a positive electrode plate coated with a conventional insulating tape, (c) Insulation of the present invention Schematic diagram of stress generated when winding a positive electrode plate coated with tape Schematic diagram of the core used in the examples of the present invention (A) Schematic front view of conventional insulating tape, (b) Schematic side view of conventional insulating tape

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base material surface of insulating tape 2 Glue surface of insulating tape 3 Current collector 4 Current collecting lead 5 Mixture surface 6 Winding direction 7 Compressive stress 8 Tensile stress 9 Load stress 10 Collapse direction of mixture 11 Core

Claims (1)

In a non-aqueous electrolyte battery created by housing a negative electrode plate coated with an electrode mixture on both sides of a current collector and a positive electrode plate through a separator, and containing a wound electrode plate group and an electrolyte in a case,
The positive electrode has a coated portion covered with the electrode mixture and an uncoated portion where the current collector is not exposed without application of the electrode mixture, and the uncoated portion is used for current collection. A lead is connected, and an insulating tape is further arranged at a boundary portion between the coated portion and the uncoated portion, and the insulating tape has a paste surface only on one end portion of the substrate surface, and the paste A non-aqueous electrolyte battery characterized in that the surface is attached only to the uncoated part.

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