JP2001052680A - Nonaqueous secondary battery and manufacture of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly provide the standard or specified position, size, shape or the like of lead terminals within a range of allowable error by connecting lead terminal materials having the size and shape larger than the size and shape of a specified lead terminal, to an electrode. SOLUTION: In this nonaqueous secondary battery 11, lead terminal materials 12a, 12b made of, for example, metallic thin plates, are respectively led through from a positive electrode and a negative electrode of a battery body. These lead terminal materials 12a, 12b have the size and shape sufficiently larger than those of specified, that is, target lead terminals in the battery, and formed on an area over a range sufficiently including the leading-through position of the lead terminals. After the formation of the nonaqueous secondary battery 11 of this constitution, the lead terminal materials 12a, 12b are respectively corrected and cut corresponding to the specified lead-through position, mutual interval (d), size and shape at a proper time or in a proper process to manufacture the specified lead terminals 13a, 13b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a non-aqueous secondary battery and a non-aqueous
Next, it relates to a method for manufacturing a battery.

[0002]

2. Description of the Related Art A secondary battery is used as a power source for driving a portable electronic device or the like for the purpose of economy and resource saving, and the use thereof has been rapidly expanding in recent years. Also, with the miniaturization and high performance of electronic devices, batteries used are required to be small, light, and high in capacity.

Conventionally, lead batteries, nickel cadmium batteries, and the like have been used as secondary batteries, but these have not overcome problems relating to energy density and weight. On the other hand, in recent years, non-aqueous lithium secondary batteries with high energy density have been put to practical use. This non-aqueous lithium secondary battery has an electrochemical structure in which lithium in the positive electrode is occluded in the negative electrode through the electrolytic solution during charging, and lithium in the negative electrode is occluded in the positive electrode through the electrolytic solution during discharging. It utilizes a reversible reaction. In other words,
Charge and discharge are performed by lithium flowing between the positive electrode and the negative electrode.

In a non-aqueous lithium secondary battery, a non-aqueous solvent in which a lithium salt is dissolved in an electrolyte is used. In order to prevent the leakage of the electrolyte, an exterior body such as a rigid steel pipe is used. The use of hard cells was essential. However, as described above, the main devices on which non-aqueous lithium secondary batteries are mounted are small portable devices. For example, products such as portable personal computers are becoming thinner, and accordingly, secondary batteries used are also smaller. Since these batteries are required to be lightweight and thin, it is extremely difficult to achieve these requirements with a secondary battery using a hard cell such as a steel pipe as described above.

As a battery that solves these problems, recently, a battery called a polymer lithium secondary battery, or simply a polymer battery or a gel battery, has been actively developed. The basic configuration of this battery is as shown in FIG. 7, which shows a schematic configuration of a cross section of a part of the battery main body, in which the battery main body 1 includes a positive electrode current collector 2 and a positive electrode active material layer 3.
The negative electrode active material layer 6 is coated on the positive electrode 4 coated with
The negative electrode 7 coated with is configured such that the coated surfaces of the active material layers face each other via a gel layer 8, and the gel layer 8 is impregnated with an electrolytic solution.

As described above, by adopting a structure in which the electrolyte is impregnated in the gel layer, liquid leakage is avoided, thereby avoiding the use of the hard cell, that is, the rigid outer package as described above. For example, a cover film is coated with an aluminum laminate film. Further, as lead terminals derived from both electrodes of the battery main body, tab terminals made of a thin metal plate (metal foil) are used to achieve lighter weight and smaller size.

[0007]

As described above, a non-aqueous secondary battery such as a polymer battery has a structure that is advantageous in terms of lightness, small size, and thinness. After welding the lead terminals to both electrodes,
Since the battery body is manufactured by stacking both electrodes and further spirally winding, the final lead-out positions of the lead terminals are likely to vary, and the mutual positional relationship, dimensions, shape, etc. are specified or specified. May deviate from the permissible error range due to the position, size, and shape of the device, resulting in inconvenience such as lowering of the yield.

In the method of manufacturing a non-aqueous secondary battery and a non-aqueous secondary battery according to the present invention, the lead terminals of the non-aqueous secondary battery are set to a standard or a specified position, size, shape, etc., accurately within an allowable error range. To be able to

[0009]

A non-aqueous secondary battery according to the present invention has a structure in which a lead terminal material having a size and a shape larger than a specified lead terminal in size and shape is connected to its electrode.

Further, the non-aqueous secondary battery according to the present invention has a structure in which an exterior body is covered, and the free end of the lead terminal material of the above-mentioned battery main body is led out from the exterior body.

The present invention also relates to a method of manufacturing a non-aqueous secondary battery in which a lead terminal is led out from an electrode of a battery main body. A step of connecting a lead terminal material having a sufficiently large shape, and thereafter, a cutting step of correcting and cutting the lead terminal material into a prescribed lead terminal lead-out position, mutual positional relationship, dimensions, and shape are performed.

As described above, in the present invention, a battery having an outer package or a battery having an outer package is not provided by employing a configuration in which a lead terminal material larger than a prescribed lead terminal is led out from the battery body. In the battery in the state, a lead terminal specified by cutting the lead terminal material can be obtained. That is, this cutting enables not only the required size and shape, but also the adjustment of the substantial lead-out position and the lead terminal interval.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a non-aqueous secondary battery according to the present invention and a method for manufacturing the same will be described with reference to FIGS. 1 and 2 for a polymer non-aqueous gel secondary battery. The battery 11 has a structure similar to that shown in FIG. 7, and includes a lead terminal material 1 made of, for example, a metal thin plate including both electrodes, that is, a positive electrode and a negative electrode.
2a and 12b are derived. These lead terminal materials 12
“a” and “12b” are formed in an area whose size and shape are defined, that is, are sufficiently larger than the prescribed lead terminals of the intended battery, and are sufficiently large to include the lead-out positions of the intended lead terminals. These lead terminal materials 12a and 12b are formed by cutting out from a thin metal plate by punching or the like.

The battery 11 having this configuration is the same as the battery 11
At an appropriate point in time or after the process is completed, the lead terminal materials 12a and 12b are corrected so as to have a prescribed lead-out position, mutual distance d, size, and shape, respectively, as shown in FIG. By cutting, the specified lead terminals 13a and 13b are manufactured.

In another embodiment, as shown in FIG. 3, for example, as shown in a perspective view of FIG. 3, the battery body 1 from which the above-mentioned lead terminal materials 12a and 12b are led out is used as an exterior body. The cover film 14 is provided. In this case, the lead terminal materials 12a and 12b are led out from the cover film 14 and these terminal materials 12a and 12b are led out.
As shown in FIG. 4, the lead terminals 13a and 13b are cut so as to have prescribed lead-out positions, mutual positional relationships, dimensions and shapes, respectively, thereby producing prescribed lead terminals 13a and 13b.

As described with reference to FIG. 7, the basic structure of the battery body 1 is such that the positive electrode 4 in which the positive electrode active material layer 3 is adhered to the positive electrode current collector 2 and the negative electrode active material layer 6 having a negative electrode 7 adhered thereto. Then, the positive electrode 4 and the negative electrode 7 are overlapped on the main surfaces on the side where the positive electrode active material layer 3 and the negative electrode active material layer 6 are applied, respectively, via a gel layer 8 containing an electrolytic solution. It can be.

As the constituent material of each part of the non-aqueous gel secondary battery according to the present invention, the constituent material of each part in the conventional non-aqueous gel secondary battery can be used.

Next, an example of one embodiment of a method for manufacturing the non-aqueous gel secondary battery according to the present invention will be described. The positive electrode 4 and the negative electrode 7 are each coated with an active material on one side of each of the current collectors 2 and 5 or on both sides (not shown).

The positive electrode 4 is manufactured by applying a positive electrode active material layer 13 to one or both surfaces of a positive electrode current collector 2 made of, for example, an Al foil and drying the same. The positive electrode active material layer 13 has a positive electrode active material of a lithium metal oxide compound represented by a general formula LiM _x O _y (M is a metal, x and y are a composition ratio of a metal M and oxygen O, respectively), and a conductivity. A positive electrode active material paint is prepared by dispersing a conductive agent such as acetylene black for raising the ink, together with a binder such as polyvinylidene fluoride, and applying it to one or both surfaces of the positive electrode current collector 12 described above. ,dry. This coating can be performed, if necessary, to obtain a desired density.

The negative electrode 17 is made of, for example, a current collector 15 made of copper foil.
The negative electrode active material layer 16 is applied to one or both surfaces of the substrate and dried. The negative electrode active material layer 16 is prepared by dispersing a low crystallization carbon powder or a high crystallization graphite powder together with a binder such as polyvinylidene fluoride as a carbon material for storing lithium ions to prepare a negative electrode active material paint. This is applied to one or both surfaces of the above-mentioned negative electrode current collector 17 and dried.
Also in this case, pressing can be performed as necessary to obtain a desired density.

The active material layer 5 and the active material layer 5 in the positive electrode 4 and the negative electrode 7 are formed in a limited manner except for the attachment portion of the lead terminal.

On the other hand, the gel layer 8 can be composed of a resin, a solvent for swelling the resin, and an electrolyte. Examples of the resin in this case include polyvinylidene fluoride, hexafluoropropylene-vinylidene fluoride copolymer, polyacrylonitrile, and the like, and γ-butyl lactone, ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate as solvents. Can be used. As the electrolyte, a lithium salt such as lithium hexafluorophosphate, lithium perchlorate, lithium tetrafluoroborate, or the like can be used.

Since the gel layer 8 is jelly-like and inferior in fluidity at room temperature, the gel layer 8 is generally made into a liquid state by applying a temperature and coated on the respective active material layers 3 and 6 of the electrodes, ie, the positive electrode and the negative electrode 4 and 7. Is done. In this way, the respective elongated electrode raw materials constituting the electrodes 4 and 7 each having the gel layer 8 formed thereon are produced.

Thereafter, these raw materials are cut into required widths and lengths, that is, cut or punched to form a positive electrode 4 and a negative electrode 7 whose essential parts are shown in perspective view in FIG. Then, for example, strip-shaped lead terminal materials 12a and 12b made of, for example, an Al foil and a Cu foil are attached to the ends of the positive electrode 4 and the negative electrode 7 where the active material layer is not formed, respectively. Welds projecting from one side edge of. Then, the positive electrode 4 and the negative electrode 7 are bonded so that the sides having the respective gel layers 8 are directly overlapped with each other, or as shown by a broken line in FIG. 7, in order to avoid physical contact between the bipolar active material layers, It can also be bonded with a separator 9 interposed. Examples of the separator 9 include a microporous film made of polyethylene or polypropylene.

In this way, the laminated long body in which the positive electrode and the negative electrode are overlapped is wound up as shown in FIG.
The battery 11 is constituted by, for example, a flat spiral wound body from which the lead terminal materials 12a and 12b are led out.

Further, the battery 11 thus configured can be covered with a cover film 14 as shown in a perspective view in FIG. This cover film 1
Numeral 4 is, for example, a laminate film in which an aluminum film is sandwiched between a thermoplastic resin film and a heat-resistant resin film. The cover film 14 is folded in two with the thermoplastic resin inside, and these two are folded. The free ends of the lead terminal materials 12a and 12b are sandwiched between the cover films 14 so as to be led out of the cover film 14, and pressed to increase the adhesion between the gel layers of the two electrodes. The periphery other than the bent edge is sealed by thermocompression bonding.

In the cover film 14, for example, a concave portion having an inner shape corresponding to the outer shape of the battery main body 1 is formed in advance in a half portion of the folded half by so-called deep drawing molding. Is folded, the cover film 14 is folded in two, the battery body 1 is sandwiched between the two, and the above-described press is performed to bring the cover film 33 into close contact with the battery body 11. Then, in this state, a sealing portion 14a is formed along the periphery of the battery main body 11 other than the bent portion of the cover film 33 in an airtight manner by, for example, thermocompression bonding, and the battery main body 1 is sealed.

When the lead terminal materials 12a and 12b are led out from the cover film 14, the lead terminal materials 12a and 12b are cut to form, for example, lead terminals 13a and 13b shown in FIG. The battery 11 is constructed.

Now, as shown in a schematic plan view of FIG. 6, lead terminals 1 having predetermined widths A and B, respectively.
3a and 13b, and distances from one edge of the cover film 14 to the lead terminals 13a and 13b are C and D, respectively, where A = B = 5 mm and C = 25 m.
Each of the batteries obtained by the above-described method of the present invention when m and D = 15 mm are set as target values, and each target when a lead terminal manufactured to have a target value from the beginning is provided as in the conventional method. Variations in the values are shown in comparison with Table 1.

[0030]

[Table 1]

From Table 1, it can be seen that, according to the present invention, especially the lead-out position of the lead terminal can be set accurately. That is, as described above, the cover film 1
In the case where the lead terminals 4 are provided, in particular, the lead-out positions of lead terminals and the mutual relationship vary greatly. Since the dimensions and shapes are corrected, they can be selected accurately.

In Table 1, the state in which the cover film 14 is provided is compared. For example, as shown in FIG. 2, the position setting, shape, and dimensions of the lead terminals are accurately determined in a state in which the cover film 14 is not covered. The same effect can be obtained when required.

Although the above-described example is a case where the present invention is applied to a polymer battery, the same effect can be obtained by applying the present invention to a battery in which lead terminals are derived from a metal thin film.

[0034]

As described above, the non-aqueous system 2 according to the present invention
The secondary battery is provided with a lead terminal material larger than the size and shape of these lead terminals so as to include the lead position of each lead terminal led out from the battery body or the outer package (cover film) 14. Things,
In the method of manufacturing a non-aqueous secondary battery according to the present invention, the lead terminal material having such a configuration is finally cut into target lead terminals. It is possible to obtain a lead terminal whose size, shape, and the like, such as the lead-out position, interval, and lead-out length, are accurately selected within an allowable error range.

Therefore, according to the non-aqueous secondary battery and the method of manufacturing the same according to the present invention, the target battery can be manufactured with a good yield, and the lead terminals of the battery can be accurately derived. There are advantages such as improvement, and even in assembling the device into various devices, assuring assembly of the device and facilitating mechanization of the assembly.

[Brief description of the drawings]

FIG. 1 is a schematic external view of an example of a non-aqueous secondary battery according to the present invention.

FIG. 2 is a schematic external view of an example of a state in which lead trimming of a non-aqueous secondary battery according to the present invention has been performed.

FIG. 3 is a schematic external view of another example of a non-aqueous secondary battery according to the present invention.

FIG. 4 is a schematic external view of another example of a state in which a lead terminal of a non-aqueous secondary battery according to the present invention has been trimmed.

FIG. 5 is a configuration diagram of an example of an electrode forming apparatus used in the method for manufacturing a non-aqueous secondary battery according to the present invention.

FIG. 6 is a plan view for explaining electrode accuracy of the non-aqueous secondary battery according to the present invention.

FIG. 7 is a schematic perspective view of a main part of an example of a battery main body of the non-aqueous secondary battery according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Battery main body, 2 ... Positive electrode collector, 3 ... Positive electrode active material layer, 4, ... Positive electrode, 5 ... Negative electrode current collector, 6 ...
..Negative electrode active material layer, 7 ... Negative electrode, 12a, 12b
・ Lead terminal material, 13a, 13b ... lead terminal, 1
4 ... Cover film (exterior)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Osamu Yamaura 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Sonny Inc. 1-1 F-term in Sony Energy Tech Co., Ltd. (reference) 5H022 AA09 AA18 BB02 BB11 CC05 CC12 CC16 CC27 5H029 AJ14 AK03 AL06 AL07 AM00 AM03 AM07 AM16 BJ04 CJ04 CJ05 DJ05 EJ01 HJ04

Claims (4)

[Claims] 1. A non-aqueous secondary battery characterized in that a lead terminal material having a size and shape larger than a specified lead terminal is led out from an electrode of a battery body. 2. The exterior body is covered by extending a free end of the lead terminal material to the outside.
3. The non-aqueous secondary battery according to 1. 3. A method for manufacturing a non-aqueous secondary battery in which a lead terminal is led out from an electrode of a battery main body, wherein the electrode constituting the battery main body has a lead terminal having a size and a shape larger than that of the lead terminal. A non-aqueous secondary battery, comprising: a step of connecting materials; and a cutting step of correcting and cutting the lead terminal material to a prescribed lead terminal lead-out position, mutual positional relationship, dimensions, and shape. Manufacturing method. 4. A step of leading the free end of the lead terminal material to the outside and covering the exterior body with the battery main body to which the lead terminal material is connected, and after the exterior body covering step, The method for producing a non-aqueous secondary battery according to claim 3, wherein the cutting step is performed on a lead terminal material.