JPH1140182A - Secondary battery, secondary battery with solar battery and watch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately use a secondary battery with a solar cell, which is a combination of a secondary battery and a solar cell, for a power source for a watch such as a wristwatch, while obtaining sufficient charging and discharging capacity when using the secondary battery as a power source for a watch. SOLUTION: In a secondary battery 10 in a center part of which a through- hole 14 is provided, while an inner periphery sealing material 17a is provided between a positive electrode can 15 and a negative electrode can 16 around the through-hole 14, an outer periphery sealing material 17b is provide between peripheral parts of the positive electrode can 15 and the negative electrode can 16. The secondary battery 10 is combined with a solar battery 20, and a driving axis 31 in a watch movement 30 is inserted into the through-hole of the secondary battery to drive a pointer 32 of the watch.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a secondary battery having a through-hole in the center, a solar battery-equipped secondary battery combining solar batteries for charging the secondary battery, and a secondary battery such as this. The present invention relates to a timepiece using a secondary battery with a solar cell as a power supply, and more particularly to a secondary battery or a secondary battery with a solar cell that can be suitably used as a power supply for a watch such as a wristwatch.

[0002]

2. Description of the Related Art Conventionally, in a timepiece such as a wristwatch, a timepiece with a solar cell using a solar cell as a power source for operating the timepiece movement has been known. If the clock movement is operated only with the generated power, the clock will stop in dark places etc.
A device has been developed in which a solar battery and a secondary battery are combined, the power generated by the solar battery is charged in the secondary battery, and the clock movement is operated by the secondary battery in a dark place or the like.

Here, when a solar cell and a secondary battery are used in combination as a power source for a watch such as a wristwatch,
In general, as shown in FIG. 1, a clock movement 3 is provided on the back side of a solar cell 2 used for a dial or the like, and the secondary battery 1 is incorporated in a part of the clock movement 3.

However, when the secondary battery 1 is incorporated in a part of the timepiece movement 3 as described above, while the thickness of the secondary battery 1 is increased to some extent, the diameter of the secondary battery 1 is reduced, and The capacity for accommodating the positive electrode material and the negative electrode material inside the battery 1 has been reduced.

[0005] For this reason, the energy density of the secondary battery 1 becomes low, and a sufficient charge / discharge capacity cannot be obtained. If the watch with a solar battery is left in a dark place for a long time, the watch stops. In addition, in order for the secondary battery 1 to have a sufficient charge / discharge capacity, it is necessary to further increase the thickness of the secondary battery 1, and the thickness of the entire solar cell watch is increased. There was a problem that would be.

As a battery for a timepiece, Japanese Patent Application Laid-Open No.
As disclosed in JP-A-158274, there is proposed a watch movement in which a donut-shaped battery is provided on the outer peripheral side of the timepiece movement.

However, in the case of such a donut-shaped battery, the difference between the inner diameter and the outer diameter of the battery is so small that the battery cannot be sufficiently filled with the positive electrode material or the negative electrode material, and the capacity of the battery cannot be increased. There was a problem that there was little.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a secondary battery used as a power source for a timepiece such as a wristwatch, and a secondary battery with a solar cell in which this secondary battery and a solar cell are combined. It is an object of the present invention to solve various problems, and in using a secondary battery as a power source for a watch,
In addition to ensuring sufficient charge / discharge capacity, this secondary battery and a secondary battery with a solar cell obtained by combining this secondary battery and a solar cell can be suitably used as a power source for a watch such as a wristwatch. The task is to make

[0009]

According to a second aspect of the present invention, there is provided a secondary battery having a through-hole formed in a central portion to solve the above-mentioned problems.
An inner peripheral sealing material was provided between the positive electrode can and the negative electrode can around the through hole, and an outer peripheral sealing material was provided between the peripheral portions of the positive electrode can and the negative electrode can.

Further, as in the secondary battery according to the first aspect, an inner peripheral sealing material is provided between the positive electrode can and the negative electrode can around the through hole, and an outer peripheral sealing material is provided between the peripheral portions of the positive electrode can and the negative electrode can. When the sealing material is provided, the inner peripheral sealing material and the outer peripheral sealing material prevent moisture from entering the secondary battery, and prevent the electrolyte solution in the secondary battery from leaking or evaporating. become.

According to a fourth aspect of the present invention, when a drive shaft of a timepiece movement for rotating a timepiece hand is inserted into a through hole in the above-mentioned secondary battery, the timepiece can move the timepiece as in the prior art. The capacity of the positive electrode and the negative electrode housed inside this secondary battery can be made larger than when the battery is incorporated in a part of the battery or when the battery is provided on the outer peripheral side of the watch movement. As a result, it can be suitably used as a power source for a timepiece.

Further, in the above secondary battery, a second aspect of the present invention is the second aspect.
As shown in (2), when the ratio (D / d) of the inner diameter D of the outer peripheral sealing material to the outer diameter d of the inner peripheral sealing material is 7/3 or more, the internal volume of the secondary battery increases. Thus, the volume of the positive electrode and the negative electrode housed inside the secondary battery can be increased, and a sufficient charge / discharge capacity can be obtained.

Various methods can be used to charge the secondary battery.
As shown in the figure, when this secondary battery is combined with a solar battery that charges the secondary battery, the secondary battery is charged by the solar battery, which is further used as a power source for a watch such as a wristwatch. It can be used suitably.

Here, as such a secondary battery, various types of secondary batteries that have been conventionally used can be used.
In order to prevent the electrolyte from leaking out or evaporating from the inside of the secondary battery, it is preferable to use a solid electrolyte secondary battery as the secondary battery, especially when the thickness is reduced. In order to obtain a high charge-discharge capacity, it is preferable to use a solid electrolyte secondary battery using lithium as an active material.

In such a solid electrolyte secondary battery using lithium as an active material, the positive electrode material constituting the positive electrode is, for example, manganese dioxide, lithium-containing manganese oxide, lithium-containing cobalt oxide, lithium-containing cobalt oxide, or the like. Vanadium oxide, lithium-containing nickel oxide, lithium-containing iron oxide, lithium-containing chromium oxide, lithium-containing titanium oxide, and the like can be used.

Examples of the negative electrode material constituting the negative electrode include carbon materials such as lithium metal, lithium alloy, graphite capable of occluding and releasing lithium ions, coke, and fired organic materials, SnO ₂ , SnO, and TiO 2. ₂ , Nb ₂
A metal oxide such as O ₃ having a lower potential than the positive electrode material can be used.

As the solid electrolyte, for example, a polymer material such as polyethylene oxide, polypropylene oxide, or a derivative of polyethylene oxide containing a lithium salt, or a non-aqueous electrolyte obtained by dissolving a lithium salt in an organic solvent is used. A gel-like material impregnated with polyacrylonitrile, polymethyl methacrylate, or the like can be used.

Examples of the lithium salt to be contained in the above-mentioned polymer material or non-aqueous electrolyte include lithium trifluoromethanesulfonate, lithium trifluoromethanesulfonimide, lithium trifluoromethanesulfonate methide and lithium hexafluorophosphate. , Lithium hexafluoroarsenate, lithium tetrafluoroborate and the like can be used.

Examples of the organic solvent used for the non-aqueous electrolyte include ethylene carbonate, propylene carbonate, butylene carbonate, vinylene carbonate, cyclopentanone, sulfolane, dimethyl sulfolane, 3-methyl-1,3-oxazolidine. -2-one, γ-butyrolactone, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, methyl propyl carbonate, butyl methyl carbonate, ethyl propyl carbonate, butyl ethyl carbonate, dipropyl carbonate, 1,2-dimethoxyethane, tetrahydrofuran, Solvents such as methyltetrahydrofuran, 1,3-dioxolan, methyl acetate, and ethyl acetate can be used alone or in combination of two or more.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a secondary battery according to an embodiment of the present invention and a case where a secondary battery with a solar cell in which this secondary battery is combined with a solar cell used in a timepiece will be specifically described, and a comparative example will be described. Thus, it will be clarified that a sufficient charge / discharge capacity can be obtained in the secondary battery according to the embodiment of the present invention. The secondary battery, the secondary battery with a solar cell, and the timepiece according to the present invention are not particularly limited to those shown in the following examples, and may be implemented by appropriately changing the scope of the invention without changing the gist thereof. You can do it.

(Embodiment 1) In this embodiment, FIG.
As shown in (1), a secondary battery 10 having a flat coin shape and having a through hole 14 in the center thereof was manufactured using the positive electrode 11, the negative electrode 12, and the solid electrolyte 13 manufactured as described below.

Here, when producing the positive electrode 11, lithium-containing cobalt dioxide LiCoO is used as the positive electrode material.
₂ , LiCoO ₂ , a carbon powder as a conductive agent, and a fluororesin powder as a binder were 85: 1.
A slurry was prepared in a weight ratio of 0: 5.
Then, this slurry was applied on a positive electrode current collector having a diameter of 16 mm by a doctor blade method, and then this was heat-treated at 100 ° C. in a vacuum to have an overall thickness of about 1 mm.
A positive electrode 11 having a thickness of 00 μm was obtained.

In producing the negative electrode 12,
A graphite powder having an average particle size of 10 μm was used as the negative electrode material, and the graphite powder and polyvinylidene fluoride as a binder were mixed in 9 parts.
A slurry was prepared so as to have a weight ratio of 5: 5. Then, the slurry was applied on a negative electrode current collector having a diameter of 16 mm, and then heat-treated at 150 ° C. to obtain a negative electrode 12 having an overall thickness of about 90 μm.

In preparing the solid electrolyte 13, polyethoxypropylene glycol acrylate having a molecular weight of about 1,000 and lithium perchlorate LiClO
_{And 4} were mixed at a weight ratio of 94: 6 and applied on the positive electrode 11 so as to have a thickness of 50 μm.
Irradiation was performed under the conditions of 00 kV and an irradiation dose of 2 Mrad to polymerize the above-mentioned polyethoxypropylene glycol acrylate, thereby forming a solid electrolyte 13 on the above-mentioned positive electrode 11.

Then, the above-mentioned negative electrode 12 was overlaid on the solid electrolyte 13 thus formed on the positive electrode 11, and in this state, a hole having a diameter of 5 mm was provided in the center thereof.

Next, in a disk-shaped positive electrode can 15 or negative electrode can 16 made of SUS having a diameter of 20 mm and a thickness of 60 μm, an inner circumference made of a modified polypropylene having a diameter of 5 mm is provided at the center. A sealing material 17a is provided, and an outer peripheral sealing material 17b made of a modified polypropylene having a ring shape having an inner diameter of 16 mm and an outer diameter of 20 mm is provided around the inner peripheral sealing material 17a and the outer peripheral sealing material 1a.
The positive electrode 11, the solid electrolyte 13, and the negative electrode 12, each having a hole having a diameter of 5 mm in the center as described above, are fitted between the positive electrode 11, the solid electrolyte 13, and the negative electrode 12 as described above. It was sandwiched between the positive electrode can 15 and the negative electrode can 16.

Next, with the positive electrode 11, the solid electrolyte 13, and the negative electrode 12 sandwiched between the positive electrode can 15 and the negative electrode can 16 as described above, the inner peripheral sealing material 17a made of modified polypropylene is used. The outer peripheral sealing material 17b is heated, and the inner peripheral sealing material 17a and the outer peripheral sealing material 17b are welded and sealed to the positive electrode can 15 and the negative electrode can 16, and thereafter, a through hole having a diameter of 1 mm is formed at the center thereof. 14 was punched out to produce a secondary battery 10 having a thickness of 300 μm. In addition,
In the case of the secondary battery 10 manufactured in Example 1, the ratio (D / d) of the inner diameter D of the outer peripheral sealing material 17b to the outer diameter d of the inner peripheral sealing material 17a is 16/5.

Then, the secondary battery 10 thus manufactured is
When using in a watch such as a wristwatch, as shown in FIG. 3, this secondary battery 10 is combined with a solar battery 20 that charges the secondary battery 10,
In a through hole 14 provided in the center of the secondary battery 10,
The drive shaft 31 of the timepiece movement 30 is inserted to drive the hands 32 of the timepiece.

Comparative Example 1 In Comparative Example 1, as shown in FIG. 4, a positive electrode 1a, a negative electrode 1b, a solid electrolyte 1
c, the size of the sealing material 1d, the positive electrode can 1e, and the size of the negative electrode can 1f are respectively different from those of the secondary battery 10 in the first embodiment.
Use the same material as above, with a diameter of 10mm and a thickness of 300μ
m was prepared.

The secondary battery 1 is accommodated in a part of the timepiece movement 3, as shown in FIG.

Next, with respect to each of the secondary batteries 10 and 1 produced in Example 1 and Comparative Example 1, at a temperature of 25 ° C. and at a charging current of 0.2 mA / cm ² , a charge termination voltage of 3. After charging to 2V, a discharge current of 0.
Discharge was performed at ² mA / cm ² to a discharge end voltage of 2.75 V, and the energy density of each of the secondary batteries 10 and 1 was measured. The results are shown in Table 1 below.

[0032]

[Table 1]

As is apparent from the results, the energy density of the secondary battery 10 of Example 1 was remarkably improved as compared with the secondary battery 1 of Comparative Example 1.

As a result, when the secondary battery 10 of the first embodiment is charged by the solar cell 20 as described above, the charge amount is larger than that of the comparative example, and the battery is left in a dark place for a long time. Even so, the clock never stopped.

Next, the secondary battery 1 in the first embodiment is described.
0, each secondary battery was prepared by changing only the ratio (D / d) of the inner diameter D of the outer peripheral sealing material to the outer diameter d of the inner peripheral sealing material, and was manufactured in the same manner as described above. The respective energy densities were measured, and the results are shown in Table 2 below.

[0036]

[Table 2]

As a result, the energy density is improved as the value of D / d is increased.
When the value of is set to 7/3 or more, a secondary battery having a high energy density can be obtained.

(Example 2) In Example 2, in the secondary battery 10 of Example 1 described above, instead of the above-mentioned solid electrolyte 13, a porous polyethylene was placed between the above-mentioned positive electrode 11 and the above-mentioned negative electrode 12. Of ethylene carbonate and diethyl carbonate in a ratio of 1: 1.
LiClO _{4 in} a mixed solvent mixed at a volume ratio of 1 mol
A non-aqueous electrolyte dissolved at a ratio of 1 / l was injected.

Then, when the secondary battery in Example 1 is compared with the secondary battery in Example 2,
Although the energy densities were all high, the liquid of Example 2 slightly leaked when stored at 60 ° C. for 2 months.

Therefore, the secondary battery using the solid electrolyte as in Example 1 could be used stably for a long time without fear of liquid leakage.

[0041]

As described above in detail, in the secondary battery according to the first aspect of the present invention, the inner peripheral sealing material is provided between the positive electrode can and the negative electrode can around the through hole, and the positive electrode can and Since the outer peripheral sealing material is provided between the peripheral portions of the negative electrode can, the inner peripheral sealing material and the outer peripheral sealing material may cause moisture to infiltrate into the secondary battery, or cause leakage of the electrolyte in the secondary battery. Evaporation is suppressed, and when the drive shaft of the timepiece movement for rotating the timepiece hand is inserted through the through-hole in this rechargeable battery, the rechargeable battery can be used as a conventional watch movement. The capacity of the positive electrode and the negative electrode housed inside this secondary battery can be made larger than when the battery is incorporated in a part of the battery or when the battery is provided on the outer peripheral side of the watch movement. La Te, now can be suitably used as a power source of the watch.

In particular, as in the secondary battery according to the second aspect,
Inner diameter D of outer peripheral sealing material with respect to outer diameter d of inner peripheral sealing material
When the ratio (D / d) is 7/3 or more, the internal volume of the secondary battery increases, and the positive electrode and the negative electrode housed in the secondary battery can be increased.
A sufficient charge / discharge capacity has been obtained.

Further, when the above secondary battery is combined with a solar battery for charging the secondary battery, the secondary battery is charged by the solar battery. It can be more suitably used as a power source for a timepiece.

[Brief description of the drawings]

FIG. 1 is an explanatory plan view of a conventional timepiece with a solar cell.

FIG. 2 is a schematic explanatory view of a secondary battery used in Example 1 of the present invention.

FIG. 3 is a schematic explanatory view showing a state in which a secondary battery and a solar battery are combined and used for a timepiece in the first embodiment of the present invention.

FIG. 4 is a schematic explanatory view of a secondary battery used in Comparative Example 1.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Secondary battery 14 Through hole 15 Positive electrode can 16 Negative electrode can 17a Inner peripheral sealing material 17b Outer peripheral sealing material 20 Solar cell 30 Watch movement 31 Drive shaft 32 Clock hand d Outside diameter of inner sealing material D Inner diameter of outer sealing material

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI H01M 16/00 H01M 16/00 (72) Inventor Toshiyuki Noma 2-5-5 Keihanhondori, Moriguchi-shi, Osaka SANYO ELECTRIC (72) Inventor Koji Nishio 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd.

Claims (5)

[Claims] 1. A secondary battery having a through hole in the center thereof, wherein an inner peripheral sealing material is provided between the positive electrode can and the negative electrode can around the through hole, and the positive electrode can and the negative electrode are provided. A secondary battery comprising an outer peripheral sealing material provided between a can and a peripheral portion. 2. The secondary battery according to claim 1, wherein
A secondary battery, wherein the ratio (D / d) of the inner diameter D of the outer peripheral sealing material to the outer diameter d of the inner peripheral sealing material is 7/3 or more. 3. The secondary battery according to claim 1 or 2,
A secondary battery with a solar battery, which is combined with a solar battery that charges the secondary battery. 4. A timepiece using a secondary battery as a power supply according to claim 1 or 2, wherein a drive shaft of a timepiece movement for rotating a timepiece hand is inserted into a through hole in the secondary battery. A watch that features. 5. A timepiece using the secondary battery with a solar cell according to claim 3 as a power supply, wherein a drive shaft of a timepiece movement for rotating a timepiece hand is inserted into a through hole of the secondary battery. A clock characterized by the following.