JPH05121099A - Thin form battery - Google Patents

Abstract

PURPOSE:To reduce heat emission and enhance the heat radiating efficiency by folding a positive electrode electrocity collecting body to retain a positive electrode active substance and a negative electricity collecting body to retain a negative electrode active material upon putting one over the other in such a way that their active material surfaces face each other. CONSTITUTION:The surface of a positive electrode electricity collecting body (of stainless steel) is subjected to screen printing with a positive electrode active material chiefly containing manganese dioxide, while the surface of a negative electrode active material (of stainless steel) undergoes screen printing with a negative electrode active substance consisting of lithium. Further these surfaces of collecting bodies are screen printed with a highpolymer solid electrolyte in such a way as enclosing the surfaces, wherein the solid electrolyte is prepared by adding lithium perchlorate to polyethylene oxide. The two collecting bodies are folded upon putting one over the other in such a way that their active substance surfaces are facing each other, wherein the ends of folding form respective electricity collection parts 8, 9, which are connected with the battery vessel in terms of electrodes. The inside where the collecting bodies are put one over the other and the inside of the battery are sealed decompressedly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin battery used in the field of equipment requiring high power, automobiles and small electronic equipment.

[0002]

2. Description of the Related Art Conventionally, this type of thin battery has a structure as shown in FIG. 7, in which a positive electrode current collector is provided above and below a power generating element in which a positive electrode active material layer, an electrolyte layer and a negative electrode active material layer are layered. A body-cum-battery and a negative electrode current-collector-cell were arranged, and the adhesive resin and the current-collector-cell were integrated.

[0003]

In such a conventional structure, when a plurality of batteries are stacked in order to obtain high power, heat during energization is accumulated between the stacks, which may deteriorate the battery performance.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and a positive electrode current collector that holds a positive electrode active material and a negative electrode current collector that holds a negative electrode active material are each provided with an active material surface. Are folded so that they face each other, and both ends are folded (A and B parts; areas where the active material is not held)
Are the respective current collectors, and the current collectors are electrically connected to the battery container, the positive electrode current collector and the negative electrode current collector are superposed, and the inside is vacuum-sealed, and / or the inside of the battery container. Was sealed under reduced pressure, the folding width of the positive electrode current collector and the negative electrode current collector that were overlapped was 3 mm to 50 mm, and the positive electrode current collector and the negative electrode current collector were 0.2 mm to 2.5 m.
m (preferably 0.5 mm to 1.5 mm) are shifted and overlapped and folded, and the shifted portion is used as a current collector,
The current collector is a vapor-deposited film, and the electrical connection between the current collector and the inner surface of the battery container is performed by ultrasonic waves or electromagnetic induction through solder, which reduces the amount of heat generation and improves heat dissipation efficiency. The purpose of the present invention is to provide a thin battery with high reliability and high reliability. In the present invention, in order to achieve the above object, the battery container was further sealed under reduced pressure.
In such a thin battery, the current collection distance is short, heat is easily radiated from the current collector, and the current collector can be continuously processed and can be cut as required, so that it can be manufactured with high productivity. ..

[0005]

EXAMPLES Details of the present invention will be described below with reference to examples. As shown in FIG. 1, a positive electrode current collector 1 (stainless steel current collector) having a width W of about 50 mm has a positive electrode active material 2 containing manganese dioxide as a main component on both surfaces (width of about 1.5 mm in the figure). Screen printing is performed with a width of about 47.5 mm in a region (B region) excluding the A region and the C region having a width of about 1 mm), and perchlorinated with polyethylene oxide so as to cover the surface of the positive electrode active material 2. The polymer solid electrolyte 3 to which lithium acid was added was also screen printed. Next, a polypropylene-based thermoadhesive resin 4 having a width of about 0.8 mm was applied or adhered to the inside of the area A and the inside of the area C. Similarly to the positive electrode current collector 1, a negative electrode current collector 5 (stainless steel current collector) having a width of about 50 mm is provided with a negative electrode active material 6 made of lithium at both ends (width A in the figure is about 1.5 mm). Screen printing with a width of about 47.5 mm is performed in a region (B region) excluding the region and the C region having a width of about 1 mm), and further, polyethylene oxide is coated with lithium perchlorate so as to cover the surface of the negative electrode active material 6. Solid electrolyte 3
Was also screen printed. Next, in the same manner as described above, the polypropylene-based thermoadhesive resin 5 having a width of about 0.8 mm was applied or adhered to the inside of the area A and the inside of the area C. The region A of the positive electrode current collector 1 and the region C of the negative electrode current collector 5 processed in this way and the region C of the positive electrode current collector 1 and the region A of the negative electrode current collector 5 face each other (B regions face each other). And the polypropylene-based thermoadhesive resin 4 was heat-sealed to each other under reduced pressure, and the inside of the current collector was hermetically sealed under reduced pressure. The sectional state at that time is shown in FIG. Next, as shown in FIG. 3, the stacked collector 7 shown in FIG. 2 was folded so that the bending width BW was about 10 mm. At this time, the positive electrode current collecting terminal 8 and the negative electrode current collecting terminal 9 are formed.

Further, as shown in FIG. 4, a positive electrode battery container (also serving as a positive electrode terminal) 10 in which a conductive material is arranged on a surface in contact with the positive electrode current collecting portion 8 and a surface in contact with the negative electrode current collecting portion 9 are electrically conductive materials. Negative electrode battery container (also serves as the negative electrode terminal) 1
The positive electrode battery container 10 and the negative electrode battery container 11 were each surrounded by the current collector 7 folded at 1, and each corner of the positive electrode battery container 10 and the negative electrode battery container 11 was vacuum-sealed with an electrically insulating material (for example, a thermoadhesive resinous substance). FIG. 5 shows a cross-sectional perspective view of the state after the sealing is taken along the line AA ′ in FIG.

The positive electrode current collector 8 is ultrasonically bonded to the positive electrode terminal 12 to which the solder 13 for stainless steel is previously bonded on the inner surface, and then is housed in a battery container and electrically insulated (for example, a heat-adhesive resinous material). It may be sealed under reduced pressure. Negative electrode current collector 9
The same applies to.

Table 1 shows the maximum values of the battery surface temperature when the battery according to the embodiment of the present invention and the battery having the conventional structure were charged and discharged.

[0009]

As described above, the battery of the present invention can reduce the temperature rise during energization. Further, the internal resistance of the battery of the present invention was reduced by about 9% as compared with the conventional battery.

[0011]

INDUSTRIAL APPLICABILITY As described above, the present invention can provide a thin battery with high productivity and high reliability, and therefore its industrial value is extremely large.

[Brief description of drawings]

FIG. 1 is a perspective view of a current collector of a thin battery of the present invention.

FIG. 2 is a perspective view of a cross section when the current collectors of the thin battery of the present invention are stacked.

FIG. 3 is a perspective view of a bent state of a current collector of the thin battery of the present invention.

FIG. 4 is a state diagram when the current collector of the thin battery of the present invention is stored in a battery container.

FIG. 5 is a cross-sectional view of the thin battery current collector of the present invention housed in a battery container.

FIG. 6 is a diagram showing another connection state of the collector terminals and the terminals of the thin battery of the present invention.

FIG. 7 is a perspective view of a conventional battery.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Positive electrode current collector 2 Positive electrode active material 3 Polymer solid electrolyte 4 Thermal adhesive resin 5 Negative electrode current collector 6 Negative electrode active material 7 Current collector 8 Positive electrode current collector 9 Negative electrode current collector 10 Positive electrode battery container 11 Negative electrode battery container 12 terminals 13 solder

Claims (8)

[Claims] 1. A thin battery comprising a power generation element in which a positive electrode active material, an electrolyte layer and a negative electrode active material are layered, and a positive electrode current collector holding the positive electrode active material and a negative electrode current collector holding the negative electrode active material. A thin battery characterized in that the active material surfaces face each other and are folded, and the folded both ends serve as respective current collecting portions, and the current collecting portions are electrically connected to a battery container. 2. The thin battery according to claim 1, wherein the positive electrode current collector and the negative electrode current collector are overlapped with each other and the inside is vacuum-sealed. 3. The thin battery according to claim 1, wherein a folded width of the positive electrode current collector and the negative electrode current collector which are overlapped with each other is 3 mm to 50 mm. 4. The positive electrode current collector and the negative electrode current collector are 0.2 mm to
The thin battery according to claim 1 or 2, wherein the thin battery is shifted by 2.5 mm, folded and overlapped, and the shifted portion is used as a current collector. 5. The positive electrode current collector and the negative electrode current collector are 0.5 mm to
3. The thin battery according to claim 1, wherein the thin battery is displaced by 1.5 mm and is folded and overlapped, and the shifted portion is used as a current collector. 6. The thin battery according to claim 1, wherein the current collector is a vapor deposition film. 7. The thin battery according to claim 1, wherein the electrical connection between the current collector and the inner surface of the battery container is connected by ultrasonic waves or electromagnetic induction via solder. 8. The thin battery according to claim 1, wherein the inside of the battery container is hermetically sealed under reduced pressure.