JP2713419B2 - Photo secondary battery - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a function of a solar cell that generates a photovoltaic voltage and a function of a normal secondary battery, and in particular, functions as an uninterruptible power supply for driving various power consuming devices. The present invention relates to an optical secondary battery having:

2. Description of the Related Art There have been proposed many power supply devices that can be used as a power source regardless of day and night by storing solar energy as electric power (Masao Kaneko, Electronics P9).
7-104, Showa 59). However, those currently in practical use store power generated by solar cells in secondary batteries,
Although this is a two-device integrated type that is intended to be used at night, this type has a complicated and large device configuration because the power generation portion and the charging portion are independent of each other.

On the other hand, the present inventors have proposed a photo secondary battery having both functions of a solar cell that generates a photovoltaic voltage with a single element and a normal secondary battery (Japanese Patent Application No. 61-92711).

SUMMARY OF THE INVENTION However, in the above-mentioned photo secondary battery, since the photovoltaic voltage generating portion and the secondary battery portion are connected in parallel in terms of electric circuit, when the secondary battery portion is not sufficiently charged, light is irradiated by light irradiation. Most of the electric power generated in the electromotive voltage generating portion is used for charging the secondary battery portion. Therefore, the current flowing through the external load connected in parallel to this was extremely small immediately after the start of light irradiation.

Means for Solving the Problems A solar cell part composed of a photovoltaic voltage generating element and a secondary battery part composed of the first battery active material electrode, the second battery active material electrode and the solid electrolyte layer are combined. In the photorechargeable battery, at least one of the first battery active material electrode and the second battery active material electrode is made of a copper chevrel compound, and the solid electrolyte layer is made of a copper ion conductive material. Connect an external load to the battery part in series,
The secondary battery portion is charged while a current is applied to the external load by the solar cell portion, and when there is no light irradiation, both ends of the external load are connected to the second electrode and the third electrode, respectively. The above problem is solved by an optical secondary battery characterized by flowing a current to a load.

Further, the above problem can also be solved by using one of the battery active material electrodes as a silver chevrel compound and the solid electrolyte layer as a silver ion conductive material.

Operation With the structure of the photo secondary battery as described above, at the time of light irradiation, the external load and the secondary battery portion are connected in series in terms of circuit. Therefore, all the electric power generated in the photovoltaic voltage generating portion by the light irradiation passes through the external load, and the problem described in the conventional example does not occur.

Example (Example 1) FIG. 1 is a cross-sectional view showing the structure of a photo secondary battery according to an example of the present invention. ITO consisting of a compound of In ₂ O ₃ and SnO ₂ was deposited at three places on a glass substrate 1 having a size of 20 × 20 mm and a thickness of 1 mm, one of which was a transparent electrode 2, and the other was a current collecting electrode 8 and 10. Next, after forming an amorphous silicon layer 3 on the transparent electrode 2 by a CVD method to a thickness of 0.04 μm, B was doped as an impurity to give a P-type semiconductor characteristic. Further, the I-type amorphous silicon layer 4 is continuously formed by the CVD method.
Form 0.4 μm. A copper metal layer 5 having a thickness of 10 μm was formed by vacuum heating evaporation so as to be connected to the I-type amorphous silicon layer and the current collecting electrode 8. Next, on the current collecting electrode 10 formed simultaneously with the transparent electrode 2, a copper chevrel compound layer 7 represented by Cu ₂ Mo ₆ S _7.8 was formed by RF sputtering to a thickness of 10 μm, and finally by the vacuum heating evaporation method. A solid electrolyte layer 6 represented by RbCu ₄ I _1.75 Cl _3.25 which is a copper ion conductive material was formed to a thickness of 1 μm, and the whole was coated with an epoxy resin 9 to obtain a battery A of this example. The operation mechanism of the battery A thus created will be described below. In the battery of the present embodiment, the semiconductor electrode described in claim 1 is a PI junction type amorphous silicon,
The battery active material electrode is a metal copper layer 5, and the second battery active material electrode is a copper chevrel layer 7. Since metallic copper has a work function smaller than that of amorphous silicon, the PI
When light is applied to the bonding surface between the amorphous silicon and the metal copper, a photovoltaic voltage is generated, and the transparent electrode 2, the P-type amorphous silicon layer 3, the I-type amorphous silicon layer 4, the metal copper layer 5, and the collecting electrode 8 A solar cell is constructed in which the transparent electrode 2 is positive and the current collecting electrode 8 is negative. On the other hand,
In the element of this configuration, a secondary battery portion is configured by the current collecting electrode 8, the metal copper layer 5, the solid electrolyte layer 6, the copper chevrel compound layer 7, and the current collecting electrode 10. Therefore, the transparent electrode 2 and the collecting electrode
When an external load is connected between 10 and the amorphous silicon portion is irradiated with light, the above-described solar cell portion, secondary battery portion, and external load are connected in series, so that the secondary battery portion is charged. Further, the external load can be driven.
When light irradiation is not performed at night or the like, connect an external load between the collecting electrodes 8 and 10 and use the charged power at the time of light irradiation to use as an uninterruptible power supply day and night. Can be.

As a comparative example, a battery in which a photovoltaic voltage generating portion and a secondary battery portion were connected in parallel in an electric circuit was prepared. FIG. 2 shows a cross-sectional view thereof. ITO is deposited in a U-shape on a glass substrate 11 having a size of 20 × 20 mm and a thickness of 1 mm, and one end is a transparent electrode 12 and the other is a negative current collecting electrode 13, and at the same time, a positive current collecting electrode 14 is also provided. Created. Next, a CdS layer 1 is formed on the transparent electrode 12.
5 was formed to a thickness of 10 μm by a vacuum heating evaporation method. Further continuously, the Cu ₂ S layer 16 is formed by the CdS by the vacuum heating evaporation method.
10 μm was formed so as to be connected to the layer 15 and the positive electrode current collecting electrode 14. A 10 μm-thick metallic copper layer 17 was formed on the current collecting electrode 13 formed simultaneously with the transparent electrode 12 by vacuum heating evaporation. Finally, RbCu ₄ I _1.75 Cl by the vacuum heating evaporation method
A solid electrolyte layer 18 represented by _3.25 was formed to a thickness of 1 μm, and the whole was coated with an epoxy resin 19 to obtain a battery B of a comparative example.

The tests described below were performed on the batteries A and B prepared by the above method. First, a fixed resistance of 10 kΩ was used as an external load.
Terminals 8 and 10 when light is blocked, and terminals 13 and 14 for battery B
And flowing to an external load while intermittently irradiating light was measured. FIG. 3 shows the results. The vertical axis shows the value of the current flowing to the external load, and the horizontal axis shows the elapsed time.
The light source used was a 1000 lux white fluorescent lamp, and irradiation and non-irradiation were repeated at a cycle of 2 hours.

As is clear from FIG. 3, in the battery B of the present example, the up and down movement of the current flowing to the external load when switching between light irradiation and non-irradiation was very large in the battery B of the comparative example. It can be said that this variation is small, and the problem of the conventional example has been solved by this.

(Example 2) Instead of the copper chevrel compound Cu ₂ Mo ₆ S _7.8 in the battery A of Example 1 and the battery B of the comparative example, a silver chevrel compound Ag was used.
Battery structure and preparation method are the same except that ₂ Mo ₆ S ₈ , RbAg ₄ I ₅ which is a silver ion conductive material instead of RbCu ₄ I _1.75 Cl _3.25 as solid electrolyte, and metallic silver instead of metallic copper The same performance evaluation test as that of Example 1 was performed on the battery C of the example. The result is shown in FIG. As can be seen, the battery C of the present embodiment also sufficiently functions as an uninterruptible power supply.

(Example 3) As a structure of a photovoltaic voltage generating portion, an MIS (Metal Insulat
or Semiconductor Metal Insulator Battery D having a photovoltaic voltage generation structure was prepared. The battery configuration and fabrication method are the same as Battery A, but MI
In order to obtain an S-type structure, a metal oxide insulating layer represented by Cu ₂ O is formed to a thickness of 5 nm between the I-type amorphous silicon layer 4 and the metal copper layer 5 in FIG. This metal oxide insulating layer was formed by heating and depositing copper metal in an oxygen atmosphere at an oxygen pressure of 1.5 × 10 ⁻² torr. On the other hand, the same performance evaluation test as in Example 1 was performed. The results are shown in FIG. It can be seen that the battery D of the third embodiment also has the same performance as the battery A of the first embodiment.

Embodiment 4 In this embodiment, the first surface of the NP junction type semiconductor electrode is
A battery E in which the battery active material electrodes were bonded was prepared.

FIG. 6 is a sectional view showing the structure of a battery according to an embodiment of the present invention. 100x100mm size, 1mm thick glass substrate 2
Electrode material consisting of In, Ag, and carbon on 0
One portion was screen printed, and one was a semiconductor electrode 21 and the other was a positive electrode current collecting electrode 22 and a negative electrode current collecting electrode 23. Next, an N-type CdS layer 24 is formed so as to have a contact portion with the semiconductor electrode 21.
Was screen-printed and dried in an infrared drying oven at a temperature of 120 ° C. to form a thin film having a thickness of 25 μm. Next, a Cu ₂ S layer 25 was formed thereon to a thickness of 50 μm by the screen printing method, and then dried at a temperature of 120 ° C. in the infrared drying oven. Further, a copper chevrel compound layer 26 represented by Cu ₂ Mo ₆ S _7.8 was formed thereon by a screen printing method to have a thickness of 100 μm so as to be in contact with the positive electrode current collecting electrode 22, and was used as a first battery active material electrode. The above-mentioned copper chevrel compound Cu ₂ M is also provided on the collecting electrode 23.
The o ₆ S _7.8 layer 27 was set to the second battery active material electrode to 100μm formed. Then, it is fired at 650 ° C in a nitrogen atmosphere. Finally RbCu ₄
After forming a solid electrolyte layer 28 represented by I _1.75 Cl _3.25 by 50 μm by the above screen printing method, the whole was annealed at 130 ° C. in a dry nitrogen atmosphere, and finally, the whole was coated with an epoxy resin 29 to form a solid electrolyte layer of the present embodiment. Battery F was used.

On the other hand, the same performance evaluation test as in Example 1 was performed. However, a load resistance of 1 kΩ was used. The results are shown in FIG.

(Example 5) In this example, a battery F having a photovoltaic voltage generation structure was formed by joining a P-type semiconductor electrode and a battery active material electrode having N-type semiconductor characteristics.

FIG. 8 is a sectional view showing the structure of an all-solid-state photovoltaic secondary battery according to an embodiment of the present invention. Size 20 × 20mm, thickness 1m
ITO was vapor-deposited at three places on a glass substrate 30 of m, and one was a transparent electrode 31 and the other was a positive electrode current collecting electrode 32 and a negative electrode current collecting electrode 33. Next, P-type CuInSe ₂ was formed as a semiconductor electrode layer 34 on the transparent electrode 31 by RF sputtering to a thickness of 0.05 μm, and a first battery active material electrode layer 35 represented by N-type Cu _1.6 S was further formed thereon. 10 μm was formed by a vacuum heating evaporation method. Next, Cu ₂ M was deposited on the positive electrode current collecting electrode 32 by RF sputtering.
copper Chevrel compound layer 36 represented by o ₆ S _7.8 to 10μm formed, RbCu ₄ I _1.75 Cl _3.25 finally by the vacuum heating deposition
A solid electrolyte layer 37 of 10 μm was formed, and the whole was coated with an epoxy resin 38 to obtain a battery F of this example. Reference numeral 39 denotes a positive electrode lead terminal made of ITO which was simultaneously formed when the transparent electrode was formed, and the first battery active material electrode 35 was formed.
Is electrically contacted. On the other hand, the same performance evaluation test as in Example 1 was performed. The results are shown in FIG. As can be seen from this, it can be said that the battery G of this embodiment also sufficiently functions as an uninterruptible power supply.

Effect of the Invention As described above, when the structure of the photorechargeable battery of the present invention is used, at the time of light irradiation, the external load and the secondary battery portion are connected in series in terms of circuit, and are generated at the photovoltaic voltage generation portion by light irradiation. Since all electric power passes through the external load, a large current can flow through the external load even during light irradiation.

[Brief description of the drawings]

1 is a structural diagram of a battery A of Example 1 of the present invention, FIG. 2 is a structural diagram of a battery B of a comparative example of Example 1, FIG. 3 is a characteristic diagram of Example 1, and FIG. Fig. 5 is a characteristic diagram of the second embodiment of the present invention, Fig. 5 is a characteristic diagram of the third embodiment of the present invention, Fig. 6 is a structural diagram of the fourth embodiment of the present invention, and Fig. 7 is a characteristic diagram of the fourth embodiment. , 8th
FIG. 9 is a structural diagram of a fifth embodiment of the present invention, and FIG. 9 is a characteristic diagram of the fifth embodiment. DESCRIPTION OF SYMBOLS 1 ... Glass base, 2 ... Transparent electrode, 3 ... P-type amorphous silicon layer, 4 ... I-type amorphous silicon layer, 5 ... Metal copper layer, 6 ... Solid electrolyte layer, 7 ... Copper chevrel compound Layers, 8 current collecting electrodes, 9 epoxy resin, 10 current collecting electrodes, 11 glass substrate, 12 transparent electrodes, 13 negative current collecting electrodes, 14 positive current collecting electrodes, 15 ……
CdS layer, 16 Cu2S, 17 Copper metal, 18 Solid electrolyte layer, 19 Epoxy resin, 20 Glass substrate, 21 Semiconductor electrode, 22 Positive current collecting electrode, 23 ... negative electrode current collector electrode, 24 ... CdS, 25 ... Cu2S, 26 ... copper chevrel compound layer, 27 ... copper chevrel compound layer, 28 ... solid electrolyte layer, 29 ... epoxy resin, 30 ... glass substrate , 31 ... Transparent electrode, 32 ... Positive current collecting electrode, 33 ... Negative current collecting electrode, 34
... CuInSe2 layer, 35 ... Cu2S, 36 ... Copper chevrel compound layer, 37 ... Solid electrolyte layer, 38 ... Poxy resin.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Tadashi Soson 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. In-company (56) References JP-A-61-91975 (JP, A) JP-A-62-47973 (JP, A) JP-A-63-241863 (JP, A) Jpn. )

Claims (2)

(57) [Claims] 1. A transparent substrate, a first electrode and a second electrode provided separately on the transparent substrate.
And a third electrode, a photovoltaic voltage generating element provided on the transparent substrate and laminated on the first electrode, and a photovoltaic voltage generating element provided on the transparent substrate and And a first battery active material electrode laminated on a second electrode; a second battery active material electrode provided on the transparent substrate and laminated on a third electrode; And a solid electrolyte layer laminated on the first battery active material electrode and the second battery active material electrode, wherein the solar cell portion comprising the photovoltaic voltage generating element and the first
In a photo-rechargeable battery having both a battery active material electrode, a second battery active material electrode, and a solid electrolyte layer, a photovoltaic secondary battery comprising: a first battery active material electrode and a second battery active material electrode; At least one is made of a copper chevrel compound, and the solid electrolyte layer is made of a copper ion conductive material, and the light source irradiates the external load in series with the secondary battery portion,
The solar cell portion charges the secondary battery portion while passing a current to the external load, and when there is no light irradiation, both ends of the external load are connected to a second electrode and a third electrode, respectively. An optical secondary battery, wherein a current flows to the external load by a secondary battery portion. 2. A transparent substrate, a first electrode and a second electrode separately provided on the transparent substrate.
And a third electrode, a photovoltaic voltage generating element provided on the transparent substrate and laminated on the first electrode, and a photovoltaic voltage generating element provided on the transparent substrate and And a first battery active material electrode laminated on a second electrode; a second battery active material electrode provided on the transparent substrate and laminated on a third electrode; And a solid electrolyte layer laminated on the first battery active material electrode and the second battery active material electrode, wherein the solar cell portion comprising the photovoltaic voltage generating element and the first
In a photo-rechargeable battery having both a battery active material electrode, a second battery active material electrode, and a solid electrolyte layer, a photovoltaic secondary battery comprising: a first battery active material electrode and a second battery active material electrode; One is made of a silver chevrel compound, and the solid electrolyte layer is made of a silver ion conductive material. At the time of light irradiation, the external load is connected in series to the secondary battery portion, and the external load is connected to the external load by the solar cell portion. The secondary battery portion is charged while a current is flowing, and when there is no light irradiation, both ends of the external load are connected to a second electrode and a third electrode, respectively, and a current is applied to the external load by the secondary battery portion. An optical secondary battery characterized by flowing electricity.