JP3730164B2 - All-solid-state battery and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an all solid state battery comprising a primary battery or a secondary battery and a method for producing the same.
[0002]
[Prior art]
As electronic devices become smaller and lighter, batteries tend to be smaller and lighter. At present, secondary batteries using a liquid electrolyte as in the past have not been reduced gradually. Instead of these, batteries using solid electrolytes have been attracting attention, and since they are solid, thin films can be formed by sputtering, vapor deposition, CVD, etc., and thinning of batteries has been achieved. (For example, JP-A-10-284130 and JP-A-59-60866). However, the terminals for taking out from the positive and negative electrodes of these all solid-state batteries are mostly single cells, as in the case of conventional batteries, when the case is the positive electrode or the negative electrode, and the cap is the counter electrode, And a case (JP-A-3-80964, JP-A-4-112460, JP-A-11-102675, etc.), and taking out with a belt-like lead terminal (JP-A-6-203826, JP-A-7-220754, JP-A-8 -162151), and the method of taking out terminals in the case of a plurality of cells is insufficient.
[0003]
[Problems to be solved by the invention]
Patterning is necessary to achieve parallel connection by stacking all-solid-state batteries as described above, and patterning is required for large batteries, and metal masks can be used when forming positive electrode, solid electrolyte, and negative electrode films. If it is a battery, it will be compatible with a mask using photolithography technology. Further, as the number of stacked cells increases, the extraction of electrode terminals becomes more complicated, the patterning technology becomes more advanced, and the cost increase is inevitable. In addition, when trying to realize multiple cells by individually connecting single cells of all solid state batteries, parallel and series connection is possible by connecting metal leads connected to each single cell, but other than power generation elements This leads to an increase in the proportion of leads, which hinders the downsizing of devices equipped with batteries. Further, in the case of a coin type having a case and a cap as electrode terminals without a lead terminal, series connection is possible by stacking, but parallel connection is impossible. As described above, all-solid-state batteries can be reduced in size and thickness, but in the case of a plurality of cells by parallel connection of single cells, the size is increased, which hinders the reduction of the size of the device. .
[0004]
The present invention provides an all-solid-state battery that can eliminate such problems and can easily realize parallel connection and series connection of a plurality of cells by simply stacking single cells, and a method for manufacturing the same. With the goal.
[0005]
[Means for Solving the Problems]
The all-solid-state battery of the present invention includes a power generation element in which a positive electrode, a solid electrolyte, and a negative electrode are stacked, sandwiched between insulating substrates, and each of the positive electrode and the negative electrode is provided on both outer surfaces of the insulating substrate. An all-solid-state battery in which an insulating substrate is provided with a contact hole connecting the current collector and the extraction electrode and a through hole connecting the same polarity of the extraction electrodes,
A part of the side surface of the all-solid-state battery is fixed and integrated with a conductive paste, and the electrode terminal can be taken out from the side surface.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described with reference to the accompanying drawings. FIG. 1 shows a structural cross-sectional view of an all solid state battery of a reference example of the present invention, and FIG. 2 shows a structural cross-sectional view in which a plurality of them are stacked. Figure 3 is a sectional view showing a structure of an all-solid-state battery of the invention according to claim 1, FIG. 4 is a sectional view showing a structure of an all-solid-state battery of the invention according to claim 3. FIG. 5 is a cross-sectional view showing the configuration of the all solid state battery of the invention according to claim 4 .
[0007]
In the reference example of the present invention, as shown in FIG. 1, an insulating substrate c having a metal pattern b (extraction electrode) and a contact hole n is arranged vertically, and a positive electrode current collector h, a positive electrode d, and a solid electrolyte e are interposed therebetween. , A negative electrode f, and a negative electrode current collector i are disposed to sandwich the power generation element g, and either the positive or negative electrode of the power generation element g, for example, the current collector i is covered with an insulating substrate c as shown in FIG. And the other current collector h is electrically connected to one of the metal patterns b on the insulating substrate c covering the metal pattern b and the contact hole n. The power generation element is sealed by bonding the upper and lower insulating substrates c, and the metal pattern b connected by the contact hole n on the front surface of the sealing body is connected by the contact hole n on the back surface. No metal pattern b A all solid state battery of a structure that is conductive with a metal pattern b via the through hole a penetrating an insulating substrate c sandwiching the power generating element g.
[0008]
According to this all-solid-state battery, there are a positive electrode terminal and a negative electrode terminal by an extraction electrode on the upper surface of the single cell, and a positive electrode terminal and a negative electrode terminal are also present on the lower surface. Parallel connection is easily possible, and the proportion of leads other than the power generation element is small, so that it does not hinder the reduction in the size of devices equipped with batteries. In addition, since the sealing and lead attachment can be performed at the same time, the number of assembly process steps can be reduced.
[0009]
In addition, a reference example of the present invention is an all solid state battery in which the above-described single cells are stacked and integrated. FIG. 2A shows a case where a plurality of single cells are stacked and connected in parallel, and the plurality of cells are integrated by an adhesive k. Even in this case, both the positive electrode terminal and the negative electrode terminal exist in the same surface of the upper surface and the lower surface, and the terminal can be easily taken out from either the upper or lower surface.
[0010]
FIG. 2 (b) shows the above-described single cells stacked and connected in series with the left and right being switched. In this case, it is possible to connect in series only by stacking a plurality of single cells, and either one of the upper surface and the lower surface of the integrated cell is one of the positive and negative electrode take-out terminals, and the other surface is either one. It becomes an electrode lead-out terminal, and it is possible to freely select which of the upper and lower surfaces is a positive terminal or a negative terminal.
[0011]
In the first aspect of the invention, as shown in FIG. 3, a part of the side surface of the all-solid-state battery formed into a plurality of cells by the parallel connection is fixed and integrated with the conductive paste m, and the electrode terminal is formed from the side surface. This is an all-solid-state battery characterized in that it can be taken out. According to this all solid-state battery, it is possible to easily take out the terminal from the side surface in addition to the top and bottom surfaces of the all solid state battery in which a plurality of single cells are stacked and integrated.
[0012]
In the invention according to claim 3 , as shown in FIG. 4, a plurality of power generation elements g are arranged inside the above-described insulating substrate c, and each power generation element g is connected in parallel by metal wiring inside the substrate (shown) or It is an all solid state battery characterized by being connected in series. According to this all-solid-state battery, a single cell is not sandwiched between two insulating substrates as described above, but a plurality of cells are sandwiched between two insulating substrates. A solid battery can be provided.
[0013]
The invention according to claim 4 is characterized in that when a plurality of the above-mentioned single cells are connected in parallel or in series, a wiring portion for electrically connecting each single cell is engaged. (FIG. 5). The wiring portions that are in phase contact also serve as the metal pattern b of the lead-out electrode, and stepped portions in opposite directions are formed on the opposing surfaces of the contacting wiring portions so as to mesh with each other. According to the all solid state battery, when a plurality of single cells are stacked and integrated, they can be stacked without causing misalignment.
[0014]
The invention according to claim 5 is an all solid state battery characterized in that the insulating substrate is a resin substrate, a ceramic substrate or a glass substrate. By using these insulating substrates, the all solid state battery according to claims 1 to 4 can be provided.
[0015]
The invention according to claim 6 is a method for manufacturing an all-solid-state battery. After the power generation element g is sandwiched between the insulating substrates c, a hole is formed by a small-diameter drill and filled with a conductive paste to form a through hole a. It is characterized by doing. By forming the through hole a after sandwiching the power generation element g, the electrode extraction terminals on the front and back surfaces of the sandwiched upper and lower insulating substrates c can be surely electrically connected to each other. The through hole a can be formed by other methods such as laser.
[0016]
As the solid electrolyte thin film material used here, a silver ion conductive solid electrolyte, a copper ion conductive solid electrolyte, a lithium ion conductive solid electrolyte, or a proton conductive solid electrolyte can be used. When a lithium ion conductive solid electrolyte thin film is used, the electrode material thin film includes Li _x CoO ₂ , Li _x NiO ₂ , Li _x Mn ₂ O ₄ , Li _x TiS ₂ , Li _x MoS ₂ , and Li _x MoO. ₂ , Li _x V ₂ O ₅ , Li _x V ₆ O ₁₃ , metallic lithium, Li _3/4 Ti _5/3 O _{4 and} other compounds that are usually used in lithium batteries can be used in combination depending on the desired battery voltage. Examples of the lithium ion conductive solid electrolyte include Li ₂ S—SiS ₂ , Li ₃ PO ₄ —Li ₂ S—SiS ₂ , LiI—Li ₂ S—SiS ₂ , LiI, LiI—Al ₂ O ₃ , Li ₃ N, _{Li 3 N-LiI-LiOH,} Li 2 O-SiO 2, Li 2 O-B 2 O 3, LiI-Li 2 S-P 2 O 5, LiI-Li 2 S-B 2 S 3, Li 3.6 Si 0.6 _{P 0.4 O 4, LiI-Li} 3 PO 4 can -P ₂ S ₅ or the like is used. In the case of using the copper ion conductor is a solid electrolyte thin film, it is possible to use metal _{Cu, Cu 2 S, Cu x} TiS 2, Cu 2 Mo 6 S 7.8 or the like. As the copper ion conductive solid electrolyte, RbCu ₄ I _1.5 Cl _3.5 , CuI—Cu ₂ O—MoO ₃ , Rb ₄ Cu ₁₆ I ₇ Cl ₁₃ or the like can be used. When a silver ion conductor is used for the solid electrolyte thin film, metal Ag, Ag _0.7 V ₂ O ₅ , Ag _x TiS ₂ or the like can be used. The silver ion conductor _{α-AgI, Ag 6 I 4} WO 4, C 6 H 5 NHAg 5 I 6, AgI-Ag 2 O-MoO 3, AgI-Ag 2 O-B 2 O 3, AgI-Ag 2 O-V ₂ O ₅ or the like can be used. If the battery to be formed when further using the proton conductive solid electrolyte of the nickel hydrogen battery is, TiFe the negative _{electrode, ZnMn 2, ZrV 2, ZrNi} 2, CaNi 5, LaNi 5, MmNi 5, Mg 2 Ni, mg ₂ Cu, the positive electrode may be used Ni (OH) _2. As the proton conductor, LaMg _0.5 Ce _0.5 O ₃ , La ₂ Zr ₂ O ₇ , α-Al ₂ O ₃ or the like can be used.
[0017]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0018]
(Example 1)
6 to 8 are sectional views in order of steps of the forming method according to the present invention. First, as shown in FIG. 6A, a metal mask 2 made of SUS304 is placed on a metal aluminum plate 1 having a size of 15 mm × 15 mm and a thickness of 300 μm. The metal mask 2 is patterned with a size of 8 mm × 5 mm. Thereafter, as shown in FIG. 6B, a LiCoO ₂ positive electrode active material 3 is sputtered. The sputtering conditions were 200 W power, Ar / O ₂ = 3/1 with 20 SCCM, 20 mTorr, and a film thickness of 5 μm, followed by annealing at 400 ° C. for 2 hours, and then Li ₂ S—SiS ₂ —Li. _{3 A} PO ₄ solid electrolyte film 4 is formed with a thickness of 2 μm, and a graphite negative electrode active material film 5 is formed thereon with a thickness of 5 μm, and sequentially laminated by a laser ablation method. The conditions of laser ablation are laser: YAG laser 266 nm, energy density: 2025 mJ / cm ² , repetition frequency 10 Hz, shot number: 36000, substrate temperature: 800 ° C., 10 ⁻² Torr. At that time, patterning is performed with a metal mask in the same manner as the formation of the positive electrode active material film (FIG. 6C). The purpose of heating the lithium cobalt oxide film at a relatively high temperature is to improve the battery characteristics by improving the ionic conductivity by crystallizing the film.
[0019]
Further, a metal copper film 6 as a negative electrode current collector is formed thereon with a thickness of 1 μm by a vacuum vapor deposition method to complete a power generation element (FIG. 6 (4)). Next, the metal mask 2 is removed as shown in FIG. Subsequently, as shown in FIG. 7 (1), the insulating substrate 7 having the patterned copper thin film 8 is opened with a 1 mm diameter drill (FIG. 7 (2)), and contact holes 9 are formed by filling with Ag paste. (FIG. 7 (3)), and the power generation element (1, 3-6) is pasted thereon with an Ag paste (FIG. 7 (4)). At this time, the metal aluminum plate 1 that is the current collector of the power generation element is electrically connected to the copper thin film (electrode extraction terminal) 8 that is the extraction electrode through the contact hole 9. Next, as shown in FIG. 8 (1), the peripheral portion of the power generation element is coated with an epoxy resin 10 (manufactured by Nitto Denko: LSS520), and an insulating substrate having a copper thin film 8 and a contact hole 9 produced in the same manner as described above. 7 was applied, and thermocompression bonded under conditions of 100 ° C., 10 minutes, 1 kgf / cm ² , the epoxy resin 10 was cured and sealed, and a unit cell was obtained. Subsequently, as shown in FIG. 8 (2), a hole penetrating the front and back of the unit cell was opened with a drill, and the opening was filled with Ag paste as shown in FIG. At this time, the copper thin film on the surface of the unit cell and the copper thin film on the back surface are electrically connected. This was stacked in four layers, and the periphery was hardened with an epoxy adhesive 12 (manufactured by Bantico Co., Ltd .: Araldite) to obtain an all-solid-state battery (FIG. 9).
[0020]
The battery thus produced was able to charge and discharge normally and a capacity of 800 μAh was obtained.
[0021]
(Example 2)
The manufacturing method was the same as in Example 1, and a solid electrolyte battery was fabricated using a ceramic substrate having a nickel film on an insulating substrate and having a plurality of through holes. The substrate was manufactured by Kyocera, and was obtained upon request. The size is a 15 mm × 15 mm 300 μm thick alumina substrate with 10 through holes of 10 μm formed in the battery formation region and filled with solder. The substrate 7 in FIG. 8 (3) is an alumina ceramic substrate.
[0022]
The battery produced in this manner was normally charged and discharged in the same manner as in Example 1, and a capacity of 800 μAh was obtained.
[0023]
(Example 3)
A cell completed in the same manufacturing method as in Example 1 (corresponding to FIG. 8 (3)) is stacked in four layers, two places around it are silver paste, and the other part is an epoxy resin (Varian made in USA) An all-solid battery was obtained by hardening with Toll Seal). Thereby, an all-solid-state secondary battery capable of taking out electrode terminals from the side surface was obtained (FIG. 3).
[0024]
The battery thus produced was able to charge and discharge normally and a capacity of 800 μAh was obtained.
[0025]
(Example 4)
The manufacturing method is the same as that of the first embodiment, and two power generation elements are arranged on an insulating wiring substrate which is an insulating substrate, and the insulating wiring substrate is placed thereon. At this time, the two power generating elements are arranged in parallel by the upper and lower patterned copper thin films. These were stacked in four layers and solidified with a surrounding epoxy resin (manufactured by Varian, USA: Toll Seal) to obtain an all-solid-state battery. As a result, an all solid state battery in which the electrode terminals can be taken out from the front and back surfaces was obtained (FIG. 4).
[0026]
The battery produced in this way was able to charge and discharge normally and a capacity of 1600 μAh was obtained.
[0027]
(Example 5)
Unit cells completed in the same manner as in Example 1 (corresponding to FIG. 8 (3)) are stacked in four layers so that the individual cells are opposite to each other when viewed from the cross section. An all-solid-state battery was obtained by solidifying with a system resin (manufactured by Varian, USA: Toll Seal). Thereby, the series connection of the cells was realized, and a voltage of 16 V was obtained (FIG. 10).
[0028]
(Example 6)
The manufacturing method is the same as in Example 1, and a part of the patterned copper thin film (electrode extraction terminal) having a thickness of 50 μm is etched to 10 μm. Since the other part of the copper thin film (electrode extraction terminal) is 50 μm, it is a copper-clad insulating substrate provided with a step of 40 μm on the copper thin film (electrode extraction terminal). The steps were stacked in four layers so as to engage with each other, and the periphery thereof was solidified with an epoxy resin (manufactured by Varian, USA: Toll Seal) to obtain an all-solid-state battery. As a result, an all-solid-state battery in which electrode terminals can be taken out from the front and back surfaces without causing a stacking deviation was obtained (FIG. 5). The copper thin film was etched by using polyimide tape (Kapton tape) to cover the portions that do not require etching, dipping in a nitric acid aqueous solution (1: 1 = H ₂ O: HNO ₃ ), and peeling off the tape.
[0029]
The battery thus produced was able to charge and discharge normally and a capacity of 800 μAh was obtained.
[0030]
(Example 7)
The manufacturing method was the same as in Example 1, and an all solid secondary battery in which the positive electrode active material was lithium manganate, the solid electrolyte was Li ₂ S—SiS ₂ —Li ₃ PO ₄ , and the negative electrode active material was graphite was obtained. As Li ion solid electrolyte, Li ₂ O—SiO ₂ , Li ₂ O—B ₂ O ₃ , Li—Li ₂ S—P ₃ O ₅ , LiI—Li ₂ S—B ₂ S ₃ , Li _3.6 Si _0.6 P _0.4 O _4, etc. _{LiI-Li 3 PO 4 -P 2} S 5 were also effective.
[0031]
【The invention's effect】
According to the all-solid-state battery of claim 1, since the positive electrode terminal and the negative electrode terminal by the extraction electrode are present on the upper surface of the single cell, and the positive electrode terminal and the negative electrode terminal are similarly present on the lower surface, the single cell Parallel connection can be easily achieved simply by stacking. In addition, since the sealing and lead attachment can be performed at the same time, the number of assembly process steps can be reduced. Further, the electrode terminal can be taken out from the side surface of the all fixed battery by the conductive paste.
[0032]
According to the all-solid-state battery of Claim 2, there exists an effect similar to Claim 1.
[0033]
According to the all solid state battery of the third aspect , in addition to the same effect as that of the first aspect, since the plurality of cells are sandwiched between the insulating substrates, a thinned, high capacity, high voltage all solid state battery can be provided.
[0034]
According to the all solid state battery of the fourth aspect, when a plurality of single cells are stacked and integrated, they can be stacked without causing misalignment.
[0035]
According to the all-solid-state battery of Claim 5, there exists an effect similar to Claim 1.
[0036]
According to the method for manufacturing an all-solid-state battery according to claim 6 , by forming the through hole after the power generation element is sandwiched between the insulating substrates, the electrode extraction terminals on the front and back surfaces of the sandwiched upper and lower insulating substrates can be reliably Electrical continuity can be obtained.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a battery in a reference example of the present invention.
2A is a cross-sectional view of a state in which a plurality of batteries are stacked and connected in parallel, and FIG. 2B is a cross-sectional view of a state in which a plurality of batteries are stacked and connected in series.
FIG. 3 is a cross-sectional view of a state in which a plurality of batteries according to an embodiment of the present invention are stacked and a part of a side surface is fixed with a conductive paste.
FIG. 4 is a cross-sectional view of a state in which a plurality of batteries are sandwiched between insulating substrates.
FIG. 5 is a cross-sectional view of a state in which a plurality of batteries are stacked in a shape in which electrode take-out terminals can be engaged with each other.
FIG. 6 is a cross-sectional view showing a manufacturing process of the power generating element of the battery in one embodiment of the present invention.
FIG. 7 is a cross-sectional view showing a process for manufacturing an insulating substrate of a battery in one embodiment of the present invention.
FIG. 8 is a cross-sectional view of a wiring process in a battery manufacturing process.
FIG. 9 is a cross-sectional view of a state in which a plurality of unit cells are stacked and connected in parallel.
FIG. 10 is a cross-sectional view of a state in which a plurality of unit cells are stacked and connected in series.
[Explanation of symbols]
a Through hole b Metal pattern (electrode extraction terminal)
c Insulating substrate d Positive electrode e Solid electrolyte f Negative electrode g Power generation element h Positive electrode current collector i Negative electrode current collector k Adhesive m Conductive paste n Contact hole 1 Metal aluminum plate (positive electrode current collector)
2 Metal Mask 3 Positive Electrode Active Material 4 Solid Electrolyte 5 Negative Electrode Active Material 6 Metal Copper Film (Negative Electrode Current Collector)
7 Insulating substrate 8 Copper thin film (electrode extraction terminal)
9 Contact hole 10 Resin 11 Through hole 12 Resin

Claims (6)

A power generation element in which a positive electrode, a solid electrolyte, and a negative electrode are laminated is sandwiched between insulating substrates, and each of the positive electrode and the negative electrode is provided on both outer surfaces of the insulating substrate, and current collection of the positive electrode and the negative electrode of the power generation element a all-solid-state battery in which a through-hole in the insulating substrate for connecting the same poles of the contact hole and the take-out electrode connected body and the take-out electrode,
An all solid state battery, wherein a part of a side surface of the all solid state battery is fixed and integrated with a conductive paste, and an electrode terminal can be taken out from the side surface.   2. An all solid state battery characterized in that the all solid state battery according to claim 1 is a single cell, and a plurality of them are stacked and integrated. It said insulating substrate inside the power generating element is more juxtaposed, all solid state battery connected in parallel or in series the connected claim 1, wherein each of the power generating element is a metal wire inside the insulating substrate. The all solid state battery of claim 2, wherein the contact wiring portion is shaped to mate to provide electrical continuity between the unit cells provided on the surface of the single cell. 2. The all solid state battery according to claim 1, wherein the insulating substrate is a resin substrate, a ceramic substrate, or a glass substrate. A power generation element in which a positive electrode, a solid electrolyte, and a negative electrode are laminated is sandwiched between insulating substrates, and each of the positive electrode and the negative electrode is provided on both outer surfaces of the insulating substrate, and current collection of the positive electrode and the negative electrode of the power generation element a all-solid-state cell production method of having a through-hole in the insulating substrate for connecting the same poles of the contact hole and the take-out electrode connected body and the take-out electrode, the through hole is the said power generating element A method for producing an all-solid-state battery, comprising: forming a hole in the insulating substrate after filling the substrate with an insulating substrate, and filling the conductive substrate with a conductive paste.

Images