JPH0521086A - Electrode and battery using this - Google Patents

Abstract

PURPOSE:To provide a new electrode arrangement structure for improving charging/discharging characteristics of battery and electrode of a thin battery, an angular battery, a layer-built cell, a flat battery, and a cylindrical battery, by improving adhesion of positive and negative plates, between which a separator is placed, and by preventing displacement. CONSTITUTION:A battery is composed of a negative electrode plate 63 and a positive electrode plate 61, between which a separator 62 is placed, or which is enveloped in a bag-like separator 62. The battery is formed out of at least two electrode plates of the same type, and the positive electrode plate 61 and the negative electrode plate 63 are alternately woven in like a fabric, which forms a single or multilayered structure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to thin batteries, prismatic batteries,
For laminated batteries, flat-plate batteries, cylindrical batteries, etc., it relates to the arrangement of electrodes, especially for improving the adhesion of the positive and negative electrode plates with a separator interposed and preventing misalignment, charging and discharging of batteries and electrodes. It contributes to the improvement of characteristics.

[0002]

2. Description of the Related Art Conventionally, a battery is basically positive and negative electrodes are opposed to each other with a separator interposed therebetween, and the negative plate is immersed in an electrolytic solution or the separator contains an electrolytic solution.
The negative electrode plate did not cross the different electrode plates alternately. For example, in a thin battery, a pair of positive and negative electrode plates (battery power generating elements) with a separator interposed between a positive electrode and a negative electrode terminal plate, which also serve as collector plates, respectively, and the peripheral portions of both terminal plates are surrounded by a frame-shaped insulating seal. A method of sealing with a body (Fig. 1), a method of stacking positive and negative plates alternately for a laminated battery and collecting current collecting terminals from positive and negative plates (Fig. 2), a separator for a cylindrical battery. It was a system in which a pair of positive and negative electrodes opposed to each other with the separator sandwiched therebetween was wound with an intervening separator between them (FIG. 3). Here, the reference numerals in FIGS.
Is a positive electrode plate, 2 is a separator, 3 is a negative electrode plate, 4 is a positive electrode terminal outer plate, 5 is a negative electrode terminal outer plate, 6 is a sealing insulating film, 11 is a positive electrode plate, 12 is a separator, 13 is a negative electrode plate, and 17 is a positive electrode. Terminal plate, 18 is a negative terminal plate, 21 is a positive plate, 22 is a separator,
23 is a negative electrode plate.

[0003]

In order to maximize the capacity of the electrode active material and to exert a sufficient discharge capacity as a primary battery and sufficient charge / discharge characteristics and cycle characteristics as a secondary battery, the electrode must be The compatibility with the electrolytic solution and the adhesion of the positive and negative electrodes through the separator are important. In a thin battery that adopts a method in which a pair of positive and negative electrodes of the related art face each other with a separator sandwiched between them, a bending stress or the like was applied at the time of manufacturing even if the positive and negative electrodes were well adhered with the separator sandwiched. In this case, the bipolar plates are distorted and the adhesiveness gradually deteriorates as shown in FIG. In FIG. 4, reference numeral 31 is a positive electrode plate 32, a separator, and 33 a negative electrode plate. In addition, since a lithium thin battery uses an organic electrolyte, if a heat fusion method, a pulse heating method, or a laser welding sealing method is used for sealing, part of the organic electrolyte remains gasified and remains in the battery system. As in the case where bending stress is applied, the adhesion between the positive and negative electrode plates via the separator may deteriorate. In the cylindrical battery that adopts the spiral winding method shown in FIG. 4, the radius of curvature becomes smaller toward the center of the winding, and a larger strain is applied. Therefore, the strain applied to the positive and negative electrode plates is not constant, and the adhesion is also small. It wasn't constant. In a completely sealed battery system in which a separator is impregnated with an electrolytic solution, if the positive electrode sandwiching the separator and the negative electrode plate adhesion are poor, the internal resistance of the battery increases and the battery capacity and cycle characteristics deteriorate. or,
When the adhesion is non-uniform, a large current is likely to flow in a strongly adhered place, which causes a decrease in capacity and a short circuit due to the non-uniform reaction in the battery system.

[0004]

SUMMARY OF THE INVENTION The present invention is a battery comprising positive and negative electrode plates with a separator interposed or wrapped between them. The positive and negative electrode plates are made of two or more identical electrode plates, and the positive and negative electrode plates are woven. The present invention relates to an electrode having a woven structure, wherein the electrode having the structure is used as each layer, and the positive electrode and the negative electrode are configured to alternately overlap with each other, and the electrode has a multilayer or laminated structure. About.
A specific battery is a thin battery, a prismatic battery, a laminated battery, a flat battery, or a cylindrical battery which is formed by spirally winding, in which a part or all of the electrodes thus formed is provided.

In order to solve the problems of the prior art as described above, the present invention comprises at least two or more identical electrode plates in a battery from a positive or negative electrode plate through a separator or wrapped in a bag-shaped separator. The positive electrode plate and the negative electrode plate have a structure in which they are woven alternately in a woven form. Here, the positive and negative plates can be applied to any battery system, such as NiCd battery system, sealed lead battery system, nickel hydrogen secondary battery system, manganese hydrogen secondary battery system, lithium primary and lithium secondary battery system, etc. Can adapt to. Further, a separator, for example, a non-woven fabric of an olefinic resin such as polyethylene or polypropylene, a non-woven fabric obtained by hydrophilically treating these, or a microporous and liquid-retaining material made of these materials, a composite thereof, a cellulosic non-woven fabric, or a nylon non-woven fabric. Etc., and the optimum one can be selected for each battery system.

The operation of the present invention will be described with reference to FIGS. In each figure, 41 and 51 are positive plates, 42 and 52 are separators, and 43 and 53 are negative plates, but the negative plates 43 and 53 are in the bags of the separators 42 and 52, and there is no direct contact between different electrodes. There is no short circuit. The negative electrode plates 43, 53 and the positive electrode plates 41, 51 contained in the bags of the separators 42, 52 have a structure in which they are alternately woven, and the positive electrode plate current collecting terminal 47 and the negative electrode plate current collecting terminal 48, Connected to 58. These materials can also be selected according to each battery system, and materials such as nickel, titanium, and stainless steel that are not corroded by the electrolytic solution are considered.
It is also possible to use by immersing in the electrolytic solution with this electrode arrangement configuration, from the viewpoint of industrial practical application and sealing, it is desirable that the separators 42, 52 impregnate the electrolytic solution,
Therefore, the above-mentioned materials are selected according to each battery system. Also, when stacking, by stacking different layers of positive and negative electrode plates so that they overlap with each other, positive and negative electrode plates are laminated facing each other on the front and back of one electrode plate,
There is no loss of current efficiency. Further, as shown in FIG. 7, if the sheets are alternately folded back, a positive and negative electrode woven arrangement sheet can be laminated. In FIG. 7, reference numeral 61 is a positive electrode plate, 62 is a separator, 63 is a negative electrode plate, 67 is a positive electrode terminal, and 68.
Is a negative electrode terminal. By this action, even if mechanical stress such as bending stress is applied to the positive and negative electrode woven sheet, the positive and negative electrodes can be kept in good contact with each other through the separator while dispersing the stress. Further, when the positive and negative electrode woven arrangement sheets are spirally wound, the stress is dispersed, and the positive and negative electrodes can be tightly wound while preventing the positional displacement of the electrodes while maintaining good adhesion between the positive and negative electrodes. It will be possible. Therefore, the internal resistance of the battery can be kept low even when external bending stress is applied.

The effect of protecting the negative electrode with the separator in this way is that the deterioration during use of the battery is more due to the electrode loss than the electrochemical deterioration due to ion inflow and outflow. In addition to the electrode loss due to the bending stress and mechanical strain described above, in the secondary battery, electrode loss occurs due to ion ingress / egress, and short circuit occurs due to dendrites. If each power source is separated by the separator as in the present invention, such a phenomenon is less likely to occur.

As described above, although a great effect is exhibited at the time of use, the internal resistance of the battery and the energy density per volume at the initial stage are not much different from the conventional products. The following table shows the comparison results for thin batteries, which show good performance.

[Table 1] It is considered that this is because the ratio of the separator is very small as compared with the amount of the active material that effectively works on the battery performance such as the electrode and the electrolytic solution.

[0009]

【Example】

(Example) An example in which the present invention is applied to a non-aqueous electrolyte lithium secondary battery will be described below with reference to the drawings. still,
The invention is not limited to this example only. In FIG. 8, 71 is a positive electrode plate, 72 is a separator, 73 is a negative electrode plate, 74 is a positive electrode terminal outer plate made of stainless steel (SUS 304, thickness 0.05 mm), and 75 is a negative electrode terminal outer plate also made of stainless steel. is there. 76A is a sealing insulating film, 76B is a sealing insulating film, 77 is a positive electrode terminal plate, and 78 is a negative electrode terminal plate. Insulating films 76A and 76B made of maleic acid-modified polyethylene resin are attached to predetermined peripheral portions of the positive electrode terminal outer plate 74 and the negative electrode terminal outer plate 75 by hot pressing. First, a positive electrode plate 71 made of a battery positive electrode mixture whose main component is chromium oxide supported on a stainless wire mesh.
2 sheets are each inserted into a bag-shaped separator 72 made of polypropylene micro-polous resin sheet (thickness: 0.05 mm), and the separator is impregnated with an electrolyte solution of propylene carbonate containing 1 mol / l of lithium perchlorate. The two positive electrode plates are connected by the positive electrode terminal plate 77. Similarly, two negative electrode plates 73 made of a nickel porous substrate coated with carbon that reversibly charges and discharges lithium are inserted into two bag-shaped separators and connected with negative electrode terminal plates 78 to impregnate the separators with an electrolytic solution. . As shown in FIGS. 8A and 8B, the positive electrode terminal plate 77 and the positive electrode terminal outer plate 74 are stacked alternately,
Place the negative electrode terminal 78 on the negative electrode terminal plate 75 by spot welding and place them, and while pressing the entire surface, pulse the frame part where the insulating film is adhered to the peripheral portions of the positive electrode terminal outer plate 74 and the negative electrode terminal outer plate 75 in advance. Heated to 180 ° C with a heating device, melt the maleic acid-modified polyethylene coating film, and then cool and solidify to form an insulating sealing body, and integrate the positive electrode terminal outer plate 74 and the negative electrode terminal outer plate 75 into a complete battery. And The positive electrode of the battery,
A bending test was carried out to evaluate the adhesion between the separator and the negative electrode, and the increase in internal resistance and the increase in discharge capacity of the battery after the bending test were used as indexes. The bending test was performed using a bending tester for a card as shown in the upper part of FIG. Here, reference numerals in FIG. 10 are 90 for a bending test card, 91 for a bending tester test card mount, 92 for a PVC plate, 93 for a test battery, 94 for a stainless steel plate, and 99 for a bending tester 90R head. . 75 mm wide table
A card 90 is placed on 91, a 90R head 99 is moved up and down by a motor and pressed against the card, and repeated bending tests are performed. The frequency of pressing the head is 100 times /
Minutes. As shown in FIG. 10, a test battery 93 was set between a PVC plate (0.58 mm) 92 and a stainless plate (SUS 304, 0.1 mm) 94 by sticking to a double-sided adhesive tape. The bending test was performed 20000 times. Table 1 and FIGS. 11 and 12 show the measurement results of the internal resistance and the discharge capacity. It is confirmed that the examples according to the present invention have an electrode arrangement configuration that is excellent in the adhesion between the positive electrode, the separator and the negative electrode and in the bending stress resistance that the various properties are superior to the comparative examples described below.

(Comparative Example) Next, a comparative example will be shown. In FIG. 9, reference numerals 81 are a positive electrode plate, 82 is a separator, 83 is a negative electrode plate, 84 is a positive electrode terminal outer plate, 85 is a negative electrode terminal outer plate, and 86A is Sealing insulation film,
86B is a sealing insulating film. In the examples, the positive electrode, the separator, and the negative electrode are not arranged alternately in the structure,
As shown in FIG. 9, a negative electrode, a separator, and a positive electrode were simply laminated in this order, and a battery having the same sealing method and the same material as that of Example except that the separator thickness was 0.10 mm was prepared. The same bending test and measurement of internal resistance and discharge capacity were performed. After bending test, positive electrode, separator,
The adhesion of the negative electrode became insufficient, the internal resistance increased, and the discharge capacity decreased. Table 1 and FIGS. 11 and 12 show the measurement results of the internal resistance and the discharge capacity.

[Table 2]

[0011]

According to the present invention, for example, in a thin battery, the adhesion of the positive electrode, the separator and the negative electrode can be improved, and the flexibility of the internal structure of the battery against bending stress can be improved. Since the resistance can be lowered, a good discharge capacity can be maintained and a battery that is strong against bending stress can be provided.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a thin battery.

FIG. 2 is a conceptual diagram of electrode stacking of a stacked battery.

FIG. 3 is a conceptual diagram of spirally winding a battery power generation element.

FIG. 4 is a conceptual diagram of poor adhesion of a battery power generation element due to bending stress.

FIG. 5 is a basic conceptual diagram of an electrode arrangement configuration of the present invention.

FIG. 6 is a conceptual diagram of stacking of the electrode arrangement constituent sheets of the present invention.

FIG. 7 is a stacking diagram of the electrode arrangement component sheet according to the present invention, which is folded back.

FIG. 8 is a schematic view of an oblique structure of the thin battery of the example.

FIG. 9 is a schematic view of an oblique structure of a thin battery of a comparative example.

FIG. 10 is a schematic cross-sectional view (a) of the head of the bending tester, the test-like card and the mounting table thereof, and an oblique configuration explanatory view of the bending test card. (B)

FIG. 11 is a discharge capacity curve of an example and a comparative example before a bending test.

FIG. 12 is a discharge capacity curve of an example and a comparative example after a bending test.

[Explanation of symbols]

1 Positive plate 2 separator 3 Negative electrode plate 4 Positive terminal outer plate 5 Negative electrode terminal outer plate 6 Sealing insulation film 11 Positive plate 12 separators 13 Negative electrode plate 17 Positive terminal plate 18 Negative electrode terminal plate 21 Positive plate 22 Separator 23 Negative electrode plate 31 Positive plate 32 separator 33 Negative electrode plate 41 Positive plate 42 separator 43 Negative electrode plate 47 Positive terminal plate 48 negative terminal plate 51 Positive plate 52 separator 53 Negative electrode plate 58 Negative electrode terminal plate 61 Positive plate 62 separator 63 Negative electrode plate 67 Positive terminal plate 68 Negative terminal plate 71 Positive plate 72 separator 73 Negative electrode plate 74 Positive terminal outer plate 75 Negative electrode terminal outer plate 76A sealing insulation film 76B Sealing insulation film 77 Positive terminal plate 78 Negative electrode terminal plate 81 Positive plate 82 separator 83 Negative plate 84 Positive terminal outer plate 85 Negative electrode terminal outer plate 86A sealing insulation film 86B sealing insulation film 90 Bending test card 91 Bending test machine Test card placement table 92 PVC board 93 test battery 94 stainless steel plate 99 Bending tester 90R head

Continuation of front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location H01M 10/40 Z 8939-4K

Claims (2)

[Claims] 1. A battery comprising a positive electrode plate and a negative electrode plate with a separator interposed or wrapped in the separator.
An electrode composed of one or more sheets of the same electrode plate, having a structure in which these positive and negative electrode plates are alternately woven into a woven fabric, and having a single-layer, multi-layer or laminated structure. 2. A thin battery, a prismatic battery, a laminated battery, a flat battery, and a cylindrical battery formed by spirally winding, having a part or all of the electrode having the structure of claim 1.