JP2000285881A - Thin battery and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize miniaturization and a thinner form of a battery by forming a generating cell obtained by laminating one or more sets of generating elements having a layer structure of a positive electrode current collector, a positive electrode active material, an electrolyte, a negative electrode active material and a negative electrode current collector so as to have a partially cut rectangular form in a plan view. SOLUTION: In a battery 1, a generating cell 2 has a simple rectangular plane form having a partially cut part 2' in the inner part, or a simple rectangular plane form having a partially cut part on the profile. A cutout part 3' having the cut plane form may be circular, elliptic, and polygonal without being limited to the rectangular form. A printed board of substantially the same form with an electronic part or a module consisting of the electronic part on board is arranged in the cutout part 3' of the battery 1, whereby the thickness as the apparatus corresponds to the thicker one, compared with the thickness of the battery 1 and the thickness of the functional electronic circuit or electronic part, and the thinning of the apparatus can be realized to save the space.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an IC card, an IC
The present invention relates to a thin battery used for thin electronic devices such as paper, a thin notebook personal computer, a mobile phone, and an information terminal, and a manufacturing method thereof.

[0002]

2. Description of the Related Art In recent years, in the fields of life, culture, medical care, and information communication, such as automatic ticket gates, automatic toll collection, FA production lines, entrance / exit management, health management, and mobile communication systems, mobile phones with built-in IC chips and thin batteries. IC cards and the like are attracting attention. Conventional cylindrical batteries and prismatic batteries are those in which a power generation element is spirally wound and housed in a robust metal housing, filled with an organic electrolyte, and hermetically sealed. It cannot be used as a power supply for thin devices such as cards. For this reason, small and thin batteries have attracted attention.
As such batteries, ultra-thin circular coin batteries and rectangular sheet-like polymer batteries are expected. Also,
In the field of portable small information and communication equipment such as notebook computers and mobile phones, the market demands higher capacity, lighter weight, thinner, and smaller batteries. Therefore, a high capacity sheet polymer battery is expected. Since the area of the power generation cell cannot be sufficiently secured with a coin battery, it is difficult to increase the capacity.
In a sheet-shaped polymer battery, a higher capacity can be easily realized by increasing the area of the sheet.

[0003] In general, there is an example in which an ultra-thin coin battery is mounted on an IC card, and a part of the IC card is cut out to provide a battery accommodating chamber, and a coin battery is inserted therein ().

Japanese Patent Application Laid-Open No. HEI 5-16619 discloses a device in which a rectangular sheet-shaped polymer secondary battery is mounted on at least one card surface of an IC card body. In this example, a polymer battery having a size of 50% to 100% of the card surface is attached to one or both sides of the card.

Japanese Patent Application Laid-Open No. 9-2608 discloses an example in which a rectangular sheet-like battery is mounted on a flexible wiring board.
There is No. 03 (). It is stated that the battery-mounted wiring board is flexible as a whole and can be folded and incorporated in electronic devices, for example, thereby contributing to downsizing of the electronic devices.

Japanese Patent Application Laid-Open No. 10-218 discloses an example in which a plurality of rechargeable batteries are attached to a wall surface or an empty space of a device.
No. 96 (). By effectively utilizing the space formed by the housing as a place where the secondary battery system is incorporated, the size and weight of the device can be reduced.

[0007] Since the electrolyte of a coin battery is a liquid, it is necessary to provide a rigid and rigid battery housing for safety. Even if it is an ultra-thin coin battery, the thickness of the battery, the degree of freedom of its shape, and its battery capacity are required. Has limitations. Further, a polymer battery is known as a bendable battery in which a rectangular power generation cell made of a polymer having a gel electrolyte is casingd with an aluminum laminated film, and is airtight and depressurized so as not to be externally affected by moisture or the like. ing.

[0008]

However, as described above, in the case where an ultra-thin coin battery is inserted into an IC card, since the exterior needs strength, the battery tends to be thick, and the thickness of the card tends to be large. However, there is a problem that the thickness of the battery is limited by the thickness of the battery, and the thickness of the card cannot be made smaller than the thickness of the battery. Furthermore, with the advancement of functions and the long-term use of IC cards, coin batteries are not expected to meet market demands for higher capacity batteries.

Further, as described above, a sheet-shaped solid polymer battery is provided on the IC card main body from 50% of the card surface to 1%.
In a structure in which the IC card is attached at a size of 00%, the thickness of the IC card is the sum of the thickness of the IC card body and the thickness of the solid polymer battery, and a thin IC card cannot be obtained.

[0010] Further, as described above, when the size of the mounting device is reduced by folding and incorporating a rectangular sheet-shaped battery on a flexible wiring board, the thickness of the flexible wiring board and the thickness of the rectangular battery are reduced. The total thickness results in the inability to reduce the thickness of the device, and the bending is limited, so that it is not versatile, or a solid battery using a solid electrolyte that cannot be bent cannot be mounted.

Further, as described above, if the space formed by the housing is effectively used as a place for mounting the secondary battery system by attaching the secondary battery to the wall surface of the device or the empty space, Is limited and not universal.

FIG. 7 shows a conventional thin battery. In FIG. 7, reference numeral 1 denotes a sheet-shaped polymer battery or a thin solid battery. Reference numeral 2 denotes the outer shape of the power generating element, and its cross section is formed by laminating at least one set of a power generating element (not shown) in which a positive electrode current collector, a positive electrode active material, an electrolyte, a negative electrode active material, and a negative electrode current collector are layered. It consists of rectangular stacked power generation elements. These power generating elements are manufactured to a desired size by cutting a sheet-shaped molded body.

As shown in FIG. 7, when there are an electronic component 5 mounted on the printed circuit board 4 and a printed circuit board, electronic component, module 5 and the like mounted on the mounting board 4 of the device, the thickness of the battery 1 is defined as t1. Assuming that the thickness of the functional electronic circuit or the electronic component 5 is t2, the thickness of the device is the total thickness of t1 and t2, and the thickness of the device is larger.
There is also wasted space. This means that, as shown in FIG. 8, even if the functional electronic circuit or the electronic component 5 to be mounted exists not at the center of the printed circuit board 4 but at the end, the thickness of the battery 1 is set to t1 and the functional electronic circuit or Assuming that the thickness of the electronic component 5 and the like is t2, the thickness of the device is the total thickness of t1 and t2, and the thickness of the device is further increased, resulting in useless space.

An object of the present invention is to provide a thin and large-area sheet-shaped polymer battery suitable for a thin device and a high capacity of a power supply, and to make the mounted device thin and small. is there.

[0015] Another object of the present invention is to provide a thin and small-sized mounting device especially for a solid-state battery in which at least one element of the power generation cell is solid and inorganic and thin. It is in.

[0016]

Means for Solving the Problems In the thin battery of the present invention, at least one set of a power generating element in which a positive electrode current collector, a positive electrode active material, an electrolyte, a negative electrode active material, and a negative electrode current collector are layered is stacked. In a thin battery including a power generation cell, the shape of the power generation cell in plan view is a shape in which a part of a rectangular shape is missing.

Further, in the above-mentioned thin battery, when a functional electronic circuit and / or an electronic component is provided, it is provided in a portion where the power generation cell is missing.

In the above-mentioned thin battery, if there is a convex portion on the exterior body of the mounted equipment, the thin battery is disposed in the chipped portion of the power generation cell.

Furthermore, it is desirable that the electrolyte of the power generation cell is a gel electrolyte or a solid electrolyte.

Further, in the method for manufacturing a thin battery according to the present invention, the shape of the power generation cell in which the positive electrode current collector, the positive electrode active material, the electrolyte, the negative electrode active material, and the negative electrode current collector are partly layered is partially omitted. In the method of manufacturing a thin battery having the above, the chipped portion of the power generation cell is formed by punching or die pressurization.

[0021]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a plan view showing an embodiment of a thin battery 1 according to the present invention, FIG. 2 is a cross-sectional view taken along the line AA ′, and FIG. 4 is an exploded view.

As shown in FIG. 3, the power generation cell 2 includes a positive electrode current collector 2a, a positive electrode active material 2b, an electrolyte 2c, and a negative electrode active material 2c.
d, a stacked structure including a power generating element in which one set (FIG. 3 (a)) or more (FIG. 3 (b)) of power generating elements in which the negative electrode current collectors 2e are layered is stacked. As shown in FIG. 2, the exterior 3 is a protective case for protecting the power generation cell 2 and is made of a metal film or sheet laminated with a resin for hermetic sealing. Is also good. Although not shown, a lead terminal is connected to the current collector.

The thin battery 1 according to the present invention comprises a power generation cell 2
Unlike the conventional example of FIG. 7 in which the planar shape of the power generating cell 2 is a simple rectangular shape, as shown in FIG.
Alternatively, as shown in FIG. 5, the power generating cell 2 is characterized in that the power generating cell 2 has a planar shape 2 having a part 2 ′ in which a simple rectangular outline is partially missing. The production of these irregular shapes is characterized by punching or press punching after forming each sheet of the power generating element or after laminating them.

The materials of the positive electrode active material, the negative electrode active material, and the solid electrolyte of the power generation cell 2 include, for example, lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium vanadium oxide, manganese dioxide,
Examples thereof include metal lithium, lithium alloy, carbon-based materials such as graphite and coke, niobium pentoxide, lithium titanium oxide, lithium transition metal composite nitride, PEO (polyethylene oxide), lithium phosphate, and the like. An electron conductive material such as carbon and acetylene black, and an additive such as a polymer binder and a lithium salt may be mixed and used.

Examples of the positive electrode current collector and the negative electrode current collector include metal foils of metal sheets made of aluminum, copper, stainless steel, nickel and the like. As the exterior body 3, insulating polyethylene terephthalate (PET) or polyethylene (P) is used in order to impart electrical insulation and decorative properties to the outer surface.
A laminated film obtained by laminating a metal sheet as in E) is used, and a protective coat such as resin or inorganic glass may be used.

The power generation cell 2 of the present invention has a structure in which at least one set of power generation elements in which a positive electrode current collector, a positive electrode active material, an electrolyte, a negative electrode active material, and a negative electrode current collector are layered is stacked. Thus, the generated voltage can be increased or the generated current can be increased. The power generation cell 2 of the present invention is particularly effective in the case of a rigid body, but is also effective in the case of flexibility. An example of the former is an all-solid-state battery in which the power generation cells are based on an inorganic material, and an example of the latter is a polymer battery in which the power generation cells are based on an organic material.

The missing planar shape 3 'in FIGS. 1 and 5
Is not necessarily rectangular, but may be circular, elliptical, polygonal, or the like. These shapes can be arbitrarily and easily formed by forming a mixture of the active material, the polymer binder, the electronic conductive material, and the like into a metal tape by tape forming by a doctor blade method or the like, and then punching and forming. . In the case of a polymer battery, it can be manufactured by adding and infiltrating a lithium salt or the like into a punched tape molded product, and then, in the case of a solid battery, it can be manufactured by firing and sintering a raw punched tape molded product.

As shown in FIGS. 4 and 6, a printed circuit board 4 on which electronic components having substantially the same shape and a module 5 composed of electronic components are mounted in the chipped portion 3 'of the battery 1 as a device. Is thicker than the thickness t1 of the battery and the thickness t2 of the functional electronic circuit or electronic component 5, and can be made thinner than before. As described above, it is apparent that the device can be made thinner, space can be saved, and the device can be downsized.

A printed circuit board, an electronic module, an optical module, an opto-electronic module, an antenna, a coil, a capacitor, a transformer, a spare battery, and the like can be disposed as functional electronic circuits or electronic components 5 in the missing portion 3 '. As a result, space saving of the device can be realized, and miniaturization and thinning can be realized. In addition, when there is a protrusion (convex portion) inside the outer case of the portable device, the space inside the outer case can be effectively used by mounting the case so that the protrusion is located in the missing part of the present invention. As a result, space saving of the device is realized, and miniaturization and thinning can be realized.

As shown in FIGS. 4 and 6, a functional electronic circuit and an electronic component 5 are mounted on the printed wiring board 4, and the functional electronic circuit and the electronic component 5 are cut off so as not to overlap with the functional electronic circuit and the electronic component 5. By simultaneously mounting the thin battery 1 having the formed portion 3 ', the size of the device can be reduced, and the thickness and size of the device can be reduced.

[0031]

EXAMPLES Example 1 A sheet-shaped polymer battery having a card size and a shape as shown in FIG. 1 was produced. First, lithium cobalt oxide (LiCoO ₂ ) was used as an active material for the positive electrode.
After mixing 11% by weight of acetylene black as an additive for imparting electronic conductivity and 9% by weight of polyvinylidene fluoride (hereinafter referred to as PVDF) as a binder, N-methyl-2-pyrrolidone (hereinafter referred to as "N-methyl-2-pyrrolidone") was added to the mixture. NMP) was added and mixed to prepare a paste for forming a positive electrode.

On the other hand, 80% by weight of lithium manganese oxide (Li ₄ Mn ₅ O ₁₂ ) as an active material constituting the negative electrode, 11% by weight of acetylene black as an additive for imparting electronic conductivity, and 9% of PVDF were used. After mixing by weight, NMP was added to and mixed with this mixture to prepare a positive electrode forming paste.

Next, an aluminum foil having a thickness of 20 μm was used as a current collector, and a paste for forming a positive electrode and a paste for forming a negative electrode were applied on the aluminum foil, dried sufficiently, and the solvent was removed. To make the thickness of the positive electrode 12
The thickness was adjusted to be 0 μm, and the thickness of the negative electrode was adjusted to be 100 μm.

On the other hand, 90% by weight of lithium titanium oxide (Li ₄ Ti ₅ O ₁₂ ) and 1% of PVDF were used as a solid electrolyte.
After mixing 0% by weight, NMP was added to the mixture and mixed to prepare a solid electrolyte forming paste.

Next, the obtained paste for forming a solid electrolyte is applied to a positive electrode or a negative electrode, and is sufficiently dried to remove the solvent.
Was adjusted.

In the solid polymer electrolyte to be impregnated and cured in the laminate, 92 wt% of monomeric polyethylene oxide and 8 wt% of LiBF ₄ as a solute were dissolved. Since LiBF ₄ is hard to dissolve directly in polyethylene oxide, it was previously dissolved in N-methyl-2-pyrrolidone and then mixed with monomeric polyethylene oxide. This mixture was impregnated into the above-mentioned laminate, and NMP was evaporated and dried at a predetermined temperature, and then impregnated with a solid polymer electrolyte and polymerized.

After the thus obtained electrode and the electrode on which the solid electrolyte was applied were cut out to a size of 80 mm × 50 mm, the central portion was cut into a shape shown in FIG.
Press punching was performed to a size of mm × 15 mm. These were vacuum-dried at a temperature of 120 ° C. for 2 hours, and then the two electrodes were attached to each other to form a laminate, which was further roll-pressed to improve the adhesion.

Next, an aluminum sheet laminated on both sides with polyethylene (PE) has a thickness of 120 to 150 μm.
m, two sheets each having a size of 85 × 53 mm were overlapped and heat-sealed to form a bag.

A laminate composed of the positive electrode current collector, the positive electrode active material, the electrolyte, the negative electrode active material, and the negative electrode current collector is inserted into the bag-shaped laminate film, and the outer periphery 3 and the inner periphery 3 ′ of the laminate film are inserted. Was heat-sealed at the same time, and the inside was evacuated at the same time to produce an air-tight power generation cell. Here, a 11 mm × 11 mm size corresponding to the outer circumference 3 ′ of FIG. 1 was cut out at the center of the bag-like laminate to produce a thin battery having the shape of FIG. The thickness of the battery thus obtained was about 0.5 mm.

Next, the thickness for the IC card is about 0.3 mm.
An electronic component consisting of a printed board having a thickness of 0.2 mm and mounting the IC chip was prepared. This electronic component has a total thickness of about 0.5 mm and a size of 10 mm × 10 mm.
Met.

Thus, when the battery 1 and the electronic component 5 were arranged as shown in FIG. 4, the total thickness was 0.5 mm which was not different from the respective thicknesses.

Incidentally, in the case of the conventional example, the total thickness was 1.0 mm which is the sum of the respective thicknesses.

Finally, a polyethylene / aluminum structure having a thickness of about 100 μm and a size of 85 × 5
An IC card is entirely covered with a 3 mm base sheet and a cover sheet.

[Embodiment 2] The shape shown in FIG.
An all-solid thin battery of mm × 20 mm size was produced.

First, lithium cobalt oxide (LiCoO ₂ ) was used as an active material for the positive electrode at 80% by weight, natural graphite as an additive for imparting electronic conductivity was 10% by weight, and Li ₂ having lithium ion conductivity was used. O-B ₂ O ₃
After 10% by weight of -ZnO glass was mixed, it was stamped and formed into the surface shape shown in FIG. 5 to obtain a formed form of a positive electrode active material body.
The formed body was fired at 550 ° C. in the air to produce a sintered body electrode. The produced positive electrode active material is about 20 m in size.
mx 20 mm, thickness about 0.2 mm. In addition, the size of the cutout portion of the surface shape was about 5 mm × 5 mm. On the other hand, 80% by weight of lithium manganese oxide (Li ₄ Mn ₅ O ₁₂ ) is used as an active material constituting the negative electrode, 10% by weight of natural graphite is used as an additive for imparting electronic conductivity, and lithium ion conductivity is provided. Li ₂ O-B
After 10% by weight of ₂ O ₃ -ZnO glass was mixed, the mixture was punched and formed into the surface shape shown in FIG. 5 to obtain a formed negative electrode active material body. The formed body was fired at 550 ° C. in the air to produce a sintered body electrode. The prepared negative electrode active material has a size of about 2
The size was 0 mm × 20 mm and the thickness was about 0.2 mm. In addition,
The size of the cutout portion of the surface shape was about 5 mm × 5 mm.

On the other hand, 90% by weight of lithium titanium oxide (Li ₄ Ti ₅ O ₁₂ ) and 1 part of PVDF were used as a solid electrolyte.
After mixing 0% by weight, NMP was added to the mixture and mixed to prepare a solid electrolyte forming paste.

Next, the obtained paste for forming a solid electrolyte is applied to a positive electrode or a negative electrode, and is sufficiently dried.
Is removed, and the thickness of the solid electrolyte is increased
m.

In the solid polymer electrolyte to be impregnated and cured in the laminate, 92 wt% of polyethylene oxide in a monomer state and 8 wt% of LiBF _{4 serving} as a solute were dissolved. Since LiBF ₄ is hard to dissolve directly in polyethylene oxide, it was previously dissolved in N-methyl-2-pyrrolidone and then mixed with monomeric polyethylene oxide. This mixture was impregnated into the above-mentioned laminate, and NMP was evaporated and dried at a predetermined temperature, and then impregnated with a solid polymer electrolyte and polymerized.

The electrode thus obtained and the electrode on which the solid electrolyte is applied are vacuum-dried at a temperature of 120 ° C. for 2 hours, and then the two electrodes are bonded together to form a laminate. Improved.

Next, the aluminum sheet was laminated on both sides with polyethylene (PE) to a thickness of 120 to 150 μm.
m, two sheets each having a size of 25 × 25 mm were overlapped and heat-sealed to form a bag.

A laminate composed of the positive electrode current collector, the positive electrode active material, the electrolyte, the negative electrode active material, and the negative electrode current collector is inserted into the bag-like laminate film, and the outer periphery 3 and the inner periphery 3 ′ of the laminate film are formed. The vicinity was heat-sealed, and at the same time, the inside was evacuated to produce an air-tight power generation cell. Here, a size of about 5 mm × 5 mm corresponding to the exterior 3 ′ of FIG. 5 was cut out at the end of the bag-like laminate to produce a thin battery having the shape of FIG. The thickness of the battery thus obtained was about 0.5 mm.

Next, a module having a thickness of about 0.5 mm made of electronic parts such as resistors and capacitors having a thickness of about 0.5 mm was prepared. Thus, when the battery and the module were arranged as shown in FIG. 6, the total thickness was about 0.5 mm which was not different from the respective thicknesses.

Incidentally, in the case of the conventional example, the total thickness was 1 mm which is the sum of the respective thicknesses.

[0054]

According to the thin battery of the present invention, the flat surface of a power generating cell comprising one or more sets of stacked power generating elements in which a positive electrode current collector, a positive electrode active material, an electrolyte, a negative electrode active material, and a negative electrode current collector are stacked in layers. Since the shape seen is a shape with a part of the rectangular shape missing, by arranging functional electronic circuits, functional parts, and an exterior body in this missing part, it is possible to make it thinner and smaller as a battery-mounted device Can be realized.

In the method for manufacturing a thin battery according to the present invention,
Since the chipped portion of the power generation cell is formed by punching or pressurized mold generation, the chipped portion can be arbitrarily and easily formed.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of a thin battery according to the present invention.

FIG. 2 is a sectional view taken along line AA ′ of FIG. 1;

FIG. 3 is a view showing a state in which one or more sets of power generating elements of the thin battery according to the present invention are stacked.

FIG. 4 is an exploded view showing an embodiment of the thin battery according to the present invention.

FIG. 5 is a view showing another embodiment of the thin battery according to the present invention.

FIG. 6 is an exploded view showing another embodiment of the thin battery according to the present invention.

FIG. 7 is a view showing a conventional thin battery.

FIG. 8 is an exploded view showing a conventional thin battery.

FIG. 9 is a view showing another conventional thin battery.

[Explanation of symbols]

2 ‥‥‥ power generation cell, 3 ‥‥‥ exterior, 3 '‥‥‥ notch

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Yoko Mishima 3-5-chome, Seika-cho, Soraku-gun, Kyoto Prefecture Inside the Central Research Laboratory, Kyocera Corporation (72) Inventor Shinji Magome 3-chome, Seika-cho, Soraku-gun, Kyoto 5 Kyocera Corporation Central Research Laboratory (72) Inventor Makoto Osaki 3-chome, Seika-cho, Soraku-gun, Kyoto Prefecture 5-5-2 Kyocera Corporation Central Research Laboratory (72) Inventor Tohru Hara, Kyodai, Soraku-cho, Kyoto Prefecture 3-5-5 Kyocera Corporation Central Research Laboratory F term (reference) 5H011 AA06 AA07 BB03 DD07 5H024 AA02 CC04 DD01 FF21 5H028 AA07 BB00 CC02 5H029 AJ00 AK03 AL03 AM00 AM16 BJ04 CJ01 CJ04 EJ12

Claims (5)

[Claims] 1. A thin battery comprising a power generating element in which at least one set of a power generating element in which a positive electrode current collector, a positive electrode active material, an electrolyte, a negative electrode active material, and a negative electrode current collector are layered is stacked. A thin battery wherein the shape in plan view is a shape in which a part of a rectangular shape is missing. 2. The thin battery according to claim 1, wherein a functional electronic circuit and / or an electronic component is disposed in a part where the power generation cell is missing. 3. The thin battery according to claim 1, wherein a projecting portion of an exterior body of the mounted device is provided in a part where the power generation cell is missing. 4. The power generation cell according to claim 1, wherein the electrolyte is a gel electrolyte or a solid electrolyte.
Or the thin battery according to 3. 5. A method of manufacturing a thin battery having a shape in which a part of a power generation cell in which a positive electrode current collector, a positive electrode active material, an electrolyte, a negative electrode active material, and a negative electrode current collector are layered is partially missing.
A method for manufacturing a thin battery, wherein the chipped portion of the power generation cell is formed by punching.