JP3197246B2 - Lithium ion conductive glass ceramics and batteries and gas sensors using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lithium ion conductive glass ceramic having high ionic conductivity, being thermally and chemically stable, and easy to manufacture.

[0002]

2. Description of the Related Art In recent years, the progress of electronics has been remarkable, and miniaturization, weight reduction, and high performance of electronic equipment have been rapidly progressing. Therefore, there is a strong demand for the development of batteries with high energy density and long life as power supplies for these devices.
In particular, expectations for lithium-ion batteries are increasing day by day.

[0003] Since lithium element has the highest redox potential of Li / Li ⁺ among all metals and has a very small mass per mole, a lithium battery can obtain a higher energy density than other batteries. it can. Further, by using the lithium ion conductive solid electrolyte, the electrolyte portion can be made thinner, the battery itself can be made thinner and lighter, and the energy density per volume can be greatly improved.

At present, lithium-ion batteries that have been put into practical use have an organic electrolyte, which makes it difficult to reduce the size and thickness of the battery, and in addition, there is a concern about danger of liquid leakage and ignition. . If it is replaced with an inorganic solid electrolyte, it is considered that an all solid state battery with high reliability and stability can be constructed.

[0005] Carbon dioxide gas generated by the combustion of fossil fuels is a major cause of the greenhouse effect, which has recently become a problem. Therefore, it is necessary to continuously monitor the concentration of carbon dioxide gas. Therefore, the establishment of these detection systems is increasing in importance in order to maintain a comfortable living environment of human society in the future.

[0006] Currently, the carbon dioxide gas detection system put into practical use is generally of the type utilizing infrared absorption, but has the disadvantage that the device is large and expensive and is susceptible to contamination. Therefore, recently, research on a compact carbon dioxide gas sensor using a solid electrolyte has been actively conducted. Among them, many studies using a lithium ion solid electrolyte have been reported.

However, in order to realize these, it is essential to develop a solid electrolyte which has high conductivity, is chemically stable, and is resistant to heat. To date, solid electrolytes having high conductivity and exceeding 10 ⁻³ S / cm at room temperature include Li ₃ N single crystals [Applied Physics].
Letters, 30 (1977) p. 621-62
2], LiI-Li ₂ SP ₂ S ₅ [Solid Sta
te Ionics, 5 (1981) p. 663], L
iI-Li ₂ S-SiS ₄ [J. Solid State
Chem. , 69 (1987) p. 252], LiI
_{-Li 2 S-B 2 S 3} [Mat. Res. Bull. , 1
8 (1983) p. 189] -based glasses are known, but these materials have drawbacks that they are difficult to produce, have poor chemical stability, and are weak to heat. In particular, when used as an electrolyte for solid state batteries, the decomposition voltage is low,
It has a fatal disadvantage that a high terminal voltage cannot be obtained.

On the other hand, since the lithium oxide solid electrolyte does not have the above-mentioned drawbacks and has a decomposition voltage higher than 3 V, there is a high possibility of practical use if it shows a high conductivity at room temperature. It is known that the conductivity of oxide glass is increased by increasing the concentration of lithium ions. However, even if a rapid quenching method is used for the purpose of vitrification, for example, the increase in the concentration of lithium ions is limited, and even if the conductivity at room temperature is high, it does not reach 10 ⁻⁶ S / cm.

Japanese Patent Application Laid-Open No. Hei 8-239218 discloses a gas sensor using a lithium ion conductive glass thin film. The conductivity of the lithium ion conductive glass thin film thus obtained is from 1.7 × 10 ^-7 to 6 × 10 ^-7. .1 × 10 ^-7 S / cm
It is not high, but something with higher conductivity is needed.

Many examples of oxide ceramics (sintered bodies) having high lithium ion conductivity have been reported. For example, Li ₄ GeO ₄ —Li ₃ VO ₄ system is 4 × 10 ⁻⁵ S / cm [Mat. Res. Bull. , 1
5 (1980) p. _{1661], Li 1-X M} X Ti 2-X (P
O ₄ ) ₃ (M = Al, Ga, Cr, etc.) is 7 × 10 ⁻⁴ S / c
m [J. Electrochem. Soc. , 137
(1990) P.A. 1023], Li _{1 + X} Al _X Ge _2-X (P
O ₄ ) ₃ system is 1.3 × 10 ^-4 S / cm [Proceedi
ngs of 8th international
meeting on lithium battery
ies, June 16-21, 1996, Nagoy
a, Japan, P .; 316 to 317] at room temperature. Compared to oxide glass, oxide ceramics are advantageous in terms of conductivity, but have the disadvantage that the manufacturing process is complicated, moldability is poor, and thinning is difficult.

[0011]

As described above, the conventional lithium ion solid electrolyte has low conductivity,
There were problems that handling was difficult and thinning was difficult. The present invention solves these problems, and provides a glass ceramic having a high lithium ion conductivity at room temperature, and further aims to realize a high-performance lithium battery or gas sensor using the glass ceramic. I have.

[0012]

As described above, a conductivity of the order of 10 ^-4 S / cm has been found in ceramics at room temperature. However, there are pores and grain boundaries that cannot be eliminated in ceramics. Their presence leads to reduced conductivity. If glass ceramics containing conductive crystals can be obtained, pores can be eliminated and grain boundaries are expected to be improved.
It can be expected to obtain a solid electrolyte having higher conductivity. Furthermore, in the case of glass ceramics, various shapes and thin films can be obtained by utilizing the properties of glass, and therefore, there are greater practical advantages than ceramics manufactured by a sintering method.

The inventor of the present invention has conducted intensive studies based on such a concept, and as a result, has found that P ₂ O ₅ , SiO ₂ , GeO ₂ , T
A glass containing iO ₂ , ZrO ₂ , M ₂ O ₃ (where M is one or two selected from Al and Ga) and a Li ₂ O component is prepared, and subjected to a heat treatment step to form a conductive crystal. Li
_{1 + X M X (Ge 1} -Y Ti Y) 2-X (PO 4) 3 (0 <X ≦ 0.
8,0 ≦ Y <1.0) from the glass, succeeded in obtaining a glass ceramic having a high lithium ion conductivity at room temperature, and a lithium battery and a gas sensor using the same were excellent. It has been found that it exhibits characteristics.

That is, according to the first aspect of the present invention, in the lithium ion conductive glass ceramic, m
ol%, P ₂ O ₅ 35 to 40%, SiO ₂ 0 to 15%, GeO ₂ 0 <to 50%, TiO ₂₀ to <50%, provided that GeO ₂ + TiO ₂ 25 to 50%, ZrO _{2 0 ~ 10%, M 2 O} 3 0.5 ~ 15%, however, M = Al, molten glass containing composition of one or Li ₂ 0 10 ~ 25%, the range of selected from the Ga Cast and get
By heat-treating the raw _{glass, Li 1 + X M X (} G
e _1-Y Ti _Y ) _2-X (PO ₄ ) ₃ (0 <X ≦ 0.8, 0 ≦ Y <
1.0) are characterized in that it is obtained to precipitate a crystalline phase, an invention according to claim 2, in _{mol%, P 2 O 5 35} ~ 40%, SiO 2 0 ~ 15%, GeO 2 0 < _{~ 50%, TiO 2 0 ~} <50%, _{however, GeO 2 + TiO 2 25 ~} 50%, ZrO 2 0 ~ 10%, M 2 O 3 0.5 ~ 15%, however, M = Al, in the Ga One or two selected from the group consisting of Li ₂ 010 to 25%, a raw glass having a composition in the range of from 25% to 50 %.
Through physical _{process, Li 1 + X M X (} Ge 1-Y Ti Y) 2-X (P
O ₄ ) ₃ (0 <X ≦ 0.8, 0 ≦ Y <1.0)
Lithium ion conductive glass ceramic obtained
And the conductivity at room temperature ^exceeds 10 ^-4 S / cm.
Lithium ion conductive glass cell
It is characterized by being Lamix, and is described in claim 3.
Placing the invention, in _{mol%, P 2 O 5 35} ~ 40%, SiO 2 0 ~ 15%, GeO 2 0 <~ 50%, TiO 2 0 ~ <50%, _{however, GeO 2 + TiO 2 25 ~} 50 _{%, ZrO 2 0 ~ 10%} , M 2 O 3 0.5 ~ 15%, where, M = Al, 1 kind or two kinds selected from among _{Ga Li 2 0 10 ~ 25%} , the composition in the range of After melt molding the raw glass contained, heat treatment
Through physical _{process, Li 1 + X M X (} Ge 1-Y Ti Y) 2-X (P
O ₄ ) ₃ (0 <X ≦ 0.8, 0 ≦ Y <1.0)
Lithium ion conductive glass ceramic obtained
And the raw glass is B, In, Sc, Fe, C
trivalent metals such as r (except Al and Ga) and Mg, C
The amount of divalent metal such as a, Sr, Ba, Zn is 10 mol%
A lithium ion conductive glass characterized by the following:
It is characterized by being ceramics,

According to a fourth aspect of the present invention, there are provided, in mol%, 35 to 40% of P ₂ O ₅ , 0 to 15% of SiO _2, 0 to 45% of GeO ₂ , and ₂₀ to <45% of TiO ₂ , A raw glass containing a composition in the range of GeO ₂ + TiO ₂ 25 to 45%, ZrO ₂ 0 to 10%, Al ₂ O ₃ 0.5 to 15%, and Li ₂ O 10 to 25% is melt-molded. After a heat treatment step, Li _{1 + X} Al _X (Ge _1-Y Ti _Y ) _2-X (PO
_{4) 3 (0 <X ≦} 0.8,0 ≦ Y <1.0) has been characterized Rukoto obtained to precipitate a crystalline phase,

According to a fifth aspect of the present invention, there is provided, in mol%, 35 to 40% of P ₂ O ₅ , 0 to 15% of SiO _2, 0 to 45% of GeO ₂ , and ₂₀ to <45% of TiO ₂ , A raw glass containing a composition of GeO ₂ + TiO ₂ 25 to 45%, ZrO ₂ 0 to 10%, Ga ₂ O ₃ 0.5 to 15%, and Li ₂ O 10 to 25% is melt-formed, After a heat treatment step, Li _{1 + X} Ga _X (Ge _1-Y Ti _Y ) _2-X (PO
_{4) 3 (0 <X ≦} 0.8,0 ≦ Y <1.0) has been characterized Rukoto obtained to precipitate a crystalline phase,

According to a sixth aspect of the present invention, there is provided a solid electrolyte for a lithium battery, wherein the lithium ion conductive glass ceramic according to the first to fifth aspects is used.

According to a seventh aspect of the present invention, in the solid electrolyte for a gas sensor, the lithium ion conductive glass ceramic according to the first to fifth aspects is used.

According to an eighth aspect of the present invention, in a lithium battery, the lithium ion conductive glass ceramic according to the first to fifth aspects is used as a solid electrolyte.

According to a ninth aspect of the present invention, in the gas sensor, the lithium ion conductive glass ceramic according to the first to fifth aspects is used as a solid electrolyte.

The composition of the glass ceramic of the present invention can be expressed on an oxide basis, similarly to the original glass. The reason why the composition of the glass ceramic is limited as described above will be described below.

[0022] After melt cooling raw glass containing the composition described above through a heat treatment _{process, Li 1 + X M X (} Ge 1-Y Ti Y)
Precipitating _2-X (PO ₄ ) ₃ (0 <X ≦ 0.8, 0 ≦ Y <1.0) crystal phase to obtain dense glass ceramics that cannot be obtained with conventional ceramics In addition, the glass ceramic exhibits very high lithium ion conductivity at room temperature. In the composition region other than the _{Li 1 + X M X (Ge} 1-Y Ti Y) 2-X (PO 4) 3 crystal phase precipitates but, since the rate is very low, to conductivity less practical Difficult to apply.

Among the above components, M ₂ O ₃ (M = A
One or two selected from l and Ga) is an important component in improving the melting property and thermal stability of glass, and adding 0.5 to 15% of this M ₂ O ₃ component As a result, the melting property and thermal stability of the glass were improved, and more surprisingly, the conductivity of the glass ceramic after the heat treatment also showed a conductivity exceeding 10 ⁻⁴ S / cm in a wide composition range. If the M ₂ O ₃ content is less than 0.5%,
Despite vitrification, the melting property and thermal stability of the glass are poor. If it exceeds 15%, the melting property is rather reduced, and the conductivity of the glass ceramic after the heat treatment is significantly reduced, and the conductivity is 10 ^-6. S / cm or less. In addition, the M
A more preferred range for the ₂ O ₃ component is 1 to 14%, and a particularly preferred range is 3 to 12%.

GeO ₂ is an essential component for the formation of glass and is also a constituent of the conductive crystalline phase. The higher the amount of GeO _{2, the} easier it is to form glass,
If the amount is less than 25 mol%, the effect is small, so that desired characteristics cannot be obtained. On the other hand, if the amount exceeds 50 mol%, the conductive crystal phase hardly precipitates. GeO ₂ is TiO ₂
And the substitution rate can be up to almost 100%. In addition, the substitution also improves the Li ion conductivity. From these, GeO ₂ = 0 <＜ 50
%, TiO ₂ = 0 to <50%, provided that GeO ₂ + TiO ₂
= 25-50%. A preferable range _{is, GeO 2 = 0 <~45%} , TiO 2 = 0~ <45%,
However, GeO ₂ + TiO ₂ = 25 to 45%, and particularly preferred ranges are GeO ₂ = 0 <〜40% and TiO ₂ = 0.
<40%, provided that GeO ₂ + TiO ₂ = 28 to 40%.

The addition of SiO ₂ can enhance the thermal stability of the raw glass, and at the same time, contributes to improving the Li ⁺ ion conductivity by dissolving Si ⁴⁺ ions in the crystal phase. However, if the amount exceeds 15%, the conductivity is rather reduced, so that it must be 15% or less. Note that a preferable range is 13% or less, and a particularly preferable range is 10% or less.

The addition of ZrO ₂ has the effect of promoting the formation of this crystal phase. But when the amount exceeds 10%,
The devitrification resistance of the raw glass is remarkably reduced, making it difficult to produce a uniform raw glass. In addition, the conductivity is also rapidly reduced, so that the raw glass must be 10% or less. Note that a preferable range is 8% or less, and a particularly preferable range is 5% or less.

Part of the Al or Ga component is B, In, S
trivalent metals such as c, Fe, Cr, etc. and Mg, Ca, Sr,
It is possible to substitute with a divalent metal such as Ba or Zn, but their amount should be 10 mol% or less. If it is added more, the production of raw glass becomes difficult,
Alternatively, the conductivity is significantly reduced.

It is also possible to add As ₂ O ₃ , Sb ₂ O ₃ , Ta ₂ O ₃ , CdO, PbO, etc. in order to further improve the melting property of the glass, but the amount thereof is 3%. The following should be restricted: If more is added, the conductivity will decrease significantly with the amount of addition.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION The lithium ion conductive glass ceramic of the present invention can be produced by the following method. That is, after a predetermined amount of each starting material is weighed and uniformly mixed, it is put into a platinum crucible and heated and melted in an electric furnace. In heating and melting, first, the raw material is decomposed at 700 ° C., and the gas components are evaporated. Next, 1300-1450 ° C
Then, the temperature is raised for 1 to 2 hours to dissolve.
Thereafter, the molten glass is cast on an iron plate to produce a plate-like glass. The glass obtained in this way is
Heat treatment at 000 ° C. for 12 to 24 hours. Through the above _{steps, Li 1 + X M X (} Ge 1-Y Ti Y) 2-X (PO 4) 3 was precipitated as a main crystal phase, high lithium ion conductivity, the glass ceramic can be obtained.

[0030]

EXAMPLES The present invention will be described below with reference to specific examples, but the present invention is not limited to these examples.

[Example 1] NH ₄ H ₂ PO ₄ ,
GeO ₂ , Al (OH) ₃ , and Li ₂ CO ₃ are used. These P ₂ O ₅ = 37.5% in mol%, GeO ₂ = 35.
It is weighed so as to have a composition of 0%, Al ₂ O ₃ = 7.5%, and Li ₂ O = 20.0%, mixed uniformly, put into a platinum crucible and melted by heating in an electric furnace. Here, first, 7
The raw material is decomposed at 00 ° C. to evaporate CO ₂ , NH ₃ and H ₂ O components. Next, the temperature was raised to 1300 ° C.
Dissolve for 5 hours. Thereafter, the molten glass is cast on a pre-warmed iron plate to produce a uniform plate-like glass. Then, annealing was performed at 520 ° C. for 2 hours to remove distortion of the glass. The glass thus obtained was sized 20 mm x 2
After cutting to 0 mm and polishing both sides, a heat treatment was performed at 750 ° C. for 12 hours to obtain a dense glass ceramic. The precipitated crystal phase was analyzed by powder X-ray diffraction to obtain Li
It was confirmed that it was _{1 + X} Al _X Ge _2-X (PO ₄ ) ₃ . FIG. 1 shows an X-ray diffraction pattern of this glass ceramic. The glass ceramic is 4.0 × 10 ^-4 S at room temperature
/ Cm.

[Example 2] NH ₄ H ₂ PO ₄ ,
GeO ₂ , Ga ₂ O ₃ , and Li ₂ CO ₃ are used. These P ₂ O ₅ = 37.5% in mol%, GeO ₂ = 40.0
%, Ga ₂ O ₃ = 5.0%, and Li ₂ O = 17.5%, are weighed so as to be uniformly mixed, then put into a platinum crucible and melted by heating in an electric furnace. Here, first, 70
The raw material is decomposed at 0 ° C. to evaporate CO ₂ , NH ₃ and H ₂ O components. Next, the temperature was raised to 1300 ° C.
Dissolve for time. Thereafter, the molten glass is cast on a pre-warmed iron plate to produce a uniform plate-like glass. Then, annealing was performed at 510 ° C. for 2 hours to remove distortion of the glass. The glass thus obtained was sized 20 mm × 20
After being cut into mm and polishing both sides, a heat treatment was performed at 800 ° C. for 12 hours to obtain a dense glass ceramic. The precipitated crystal phase was analyzed by powder X-ray diffraction to obtain Li
It was confirmed to be _{1 + X} Ga _X Ge _2-X (PO ₄ ) ₃ . Its glass ceramics is 2.0 × 10 ^-4 S / cm at room temperature
High conductivity.

Example 3 NH ₄ H ₂ PO ₄ ,
GeO ₂ , TiO ₂ , Al ₂ O ₃ and Li ₂ CO ₃ are used.
These P ₂ O ₅ = 37.5% in mol%, GeO ₂ = 3
0.0%, TiO ₂ = 10%, Al ₂ O ₃ = 5.0%, L
It is weighed so as to have a composition of i ₂ O = 17.5%, mixed uniformly, and then placed in a platinum crucible and heated and melted in an electric furnace. Here, the raw material is first decomposed at 700 ° C.
O _2, NH _3, evaporate of H ₂ O component. Then 1400 ° C
And melt at that temperature for 1.5 hours. afterwards,
The molten glass is cast on a pre-warmed iron plate to produce a uniform plate-like glass. Then, annealing was performed at 540 ° C. for 2 hours to remove distortion of the glass. The glass thus obtained was cut into a size of 20 mm × 20 mm, and both sides were polished, and then heat-treated at 850 ° C. for 12 hours to obtain a dense glass ceramic. The precipitated crystal phase was analyzed by powder X-ray diffraction to obtain Li _{1 + X} Al _X (Ge _2-Y T
i _Y ) _2-X (PO ₄ ) ₃ . The glass ceramic showed a high conductivity of 2.0 × 10 ⁻⁴ S / cm at room temperature.

[Examples 4 to 10] Samples of Examples 4 to 10 were produced in the same manner as in Example 2. Tables 1 and 2 show the composition and the conductivity at room temperature in each example.
The conductivity of the glass ceramic was measured in the range of 10 ^{−2 to} 3 × 10 ⁺⁷ Hz by the AC impedance, and the resistance of the sample (the sum of the resistance of the particles and the grain boundary) was obtained from the Cole-Cole plot. The conductivity was calculated according to the equation σ = (t / A) (1 / R). (Σ: conductivity, t: sample thickness, A: electrode area, R: sample resistance)

[0035]

[Table 1]

[0036]

[Table 2]

[Embodiment 11] As a typical embodiment of a lithium battery, FIG. 2 shows an example (cross-sectional view) of a flat battery using the lithium ion conductive glass ceramics of Embodiment 4 as a solid electrolyte. This battery includes a negative electrode can 6, a negative electrode current collector 4 (a conductive thin film and a thin plate of aluminum or stainless steel or the like are used), a negative electrode 2, a lithium ion conductive glass ceramic 1, a positive electrode 3, and a positive electrode current collector 5.
(A conductive thin film and a thin plate of aluminum, stainless steel, etc. are used.), A positive electrode can 7, an insulating filler 8 (made of polypropylene), and the like. The positive and negative electrodes 2 and 3 face each other via a lithium ion conductive glass ceramic and are accommodated in a case where positive and negative electrode cans 6 and 7 are formed. Positive electrode 3
Is connected to the positive electrode can 7 via the positive electrode current collector 5, and the negative electrode 2 is connected to the negative electrode can 6 via the negative electrode current collector 4. Chemical energy generated inside the battery can be taken out from both terminals of the positive electrode can and the negative electrode cans 6 and 7 as electric energy. As for members constituting the battery according to the present invention, various materials conventionally used can be used other than the substances described above except for the solid electrolyte portion.

Here, the thickness of the lithium ion conductive glass ceramic must be thin, at least 1 mm.
Or less, preferably 0.5 mm or less. Various materials have been proposed and announced for the material of the positive electrode 3, and typical examples include LiCoO ₂ and Li _{1 + X} V ₃ O ₈ . Similarly, various ideas and announcements have been made for the material of the negative electrode 2, and typical examples thereof include Li ₄ Ti ₅ O ₁₂ and carbon.

The positive and negative poles 2 and 3 formed on opposite surfaces of the lithium ion conductive glass ceramic,
Regarding the collector electrodes 4 and 5 formed on the positive and negative poles, a previously prepared electrode is sequentially superimposed and attached, or the poles and the current collector are ion-sputtered, CVD,
A method of forming sequentially by a screen printing method, a coating method, a sol-gel method, an ion plating method, an ion beam evaporation method, an MBE method, a vacuum evaporation method, an electron beam evaporation method, or the like can also be used.

In the comparative examples, titanium oxide: 1.7 mol,
Lithium carbonate: 0.7 mol, ammonium phosphate: 3.
0 mol, aluminum oxide: 0.2 mol was mixed in an agate mortar, pressed and formed into pellets, and then 900 ° C.
Baked for 2 hours, and the obtained baked product was again pulverized in an agate mortar, passed through a 400-mesh sieve, pressed into a pellet, sintered at 1000 ° C. for 2 hours, and processed into a thin plate. Was used as a solid electrolyte. FIG. 4 shows an efficiency discharge characteristic diagram of the battery of FIG. 2 and a battery using the solid electrolyte of the comparative example.

Embodiment 12 As a typical embodiment of the gas sensor, FIG. 3 shows an example (cross-sectional view) of a carbon dioxide gas sensor using the lithium ion conductive glass ceramic of Embodiment 4 as a solid electrolyte. L according to the above embodiment
After polishing both upper and lower surfaces of the i-ion conductive glass ceramic to a thickness of 1 to 2 mm, preferably 1 mm or less, more preferably 0.5 mm or less, a metal carbonate layer, preferably lithium carbonate or A mixture of lithium carbonate and another carbonate is formed by an ion sputtering method.

Next, a platinum mesh connected with a lead wire is attached to this surface, and a carbonate layer is formed again to fix the platinum mesh. On the other surface, a platinum thin film formed by a vapor deposition method is formed, and a lead wire is connected to the platinum thin film. Since this sensor generates an electromotive force between the electrodes due to the dissociation equilibrium of the carbonate by the carbon dioxide in the carbon dioxide gas mixture, the carbon dioxide concentration can be known from the measurement of the electromotive force. .

The method of forming the carbonate layer and the electrode layer is not limited to the above, but may be CVD, screen printing, coating, sol-gel, ion plating, ion beam evaporation, MBE, vacuum evaporation. Can be formed by an electron beam evaporation method or the like. FIG. 5 shows the electromotive force characteristics of this gas sensor due to the partial pressure of carbon dioxide at room temperature.

[0044]

As described above, the lithium ion conductive glass-ceramic according to the present invention has a very high lithium ion conductivity, is easy to produce, is chemically stable, and is thermally strong, and thus has a high battery (fuel) capacity. It can be applied to various electrochemical devices, including batteries and gas sensors.

[Brief description of the drawings]

FIG. 1 shows an X-ray diffraction pattern of the glass ceramic of Example 1.

FIG. 2 is a view showing a typical structure of a lithium battery using a lithium ion solid electrolyte according to Embodiment 2 of the present invention.

FIG. 3 is a view showing a typical structure of a gas sensor using a lithium ion solid electrolyte according to Embodiment 2 of the present invention.

4 is an efficiency discharge characteristic diagram of the battery shown in FIG.

5 is an electromotive force characteristic diagram of the gas sensor shown in FIG. 3 at a room temperature at a partial pressure of carbon dioxide gas.

[Explanation of symbols]

 1, lithium ion conductive glass ceramics 2, negative electrode 3, positive electrode 4, negative electrode current collector 5, positive electrode current collector 6, negative electrode can 7, positive electrode can 8, insulating filler 9, metal carbonate 10, electrode 11, lithium Ion conductive glass ceramics 12, electrode 13, lead wire 14, lead wire 15, package material

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI H01M 8/02 G01N 27/58 Z (56) References JP-A-5-139781 (JP, A) JP-A-3-123848 ( JP, A) JP-A-2-302307 (JP, A) Imanaka, et al. , "Lithium conduc ting amorphous sol id electrolytes ob tained by explosio n method", Solid St ate Ionics, 62 (3,4), 1993, p167-171 (58) investigated the field (Int.Cl. ^7, DB name) C03C 1/00-14/00 H01B 1/00-1/24 H01M 6/00-6/22 G01N 27/406 JOIS WPI INSPEC

Claims (9)

(57) [Claims] 1. mol%, P ₂ O ₅ 35 to 40%, SiO ₂ 0 to 15%, GeO ₂ 0 to 50%, TiO ₂₀ to <50%, provided that GeO ₂ + TiO ₂ 25 to 50 %, ZrO ₂ 0 to 10%, M ₂ O ₃ 0.5 to 15%, where M = one or two kinds of Li ₂ 010 to 25% selected from Al and Ga. Cast the molten glass containing
By heat-treating the raw _{glass, Li 1 + X M X (} G
e _1-Y Ti _Y ) _2-X (PO ₄ ) ₃ (0 <X ≦ 0.8, 0 ≦ Y <
1.0) characterized in that it can be obtained by precipitating a crystal phase,
Lithium ion conductive glass ceramics. 2. In mol%, P _Two O _Five  35-40%, SiO _Two  0 to 15%, GeO _Two  0 <~ 50%, TiO _Two  0 to <50%, However, GeO _Two + TiO _Two  25-50%, ZrO _Two  0-10%, M _Two O _Three  0.5 to 15%, However, M = one or two selected from Al and Ga Li _Two 0 10 to 25%, The raw glass containing the composition in the range of
Through the process, Li _{1 + X} M _X (Ge _1-Y Ti _Y ) _2-X (P
O _Four ) _Three (0 <X ≦ 0.8, 0 ≦ Y <1.0)
Lithium ion conductive glass ceramic obtained
And the conductivity at room temperature is 10 ^-4 S / cm
Lithium ion transmission Conductive glass
Ceramics. 3. mol%, P _Two O _Five  35-40%, SiO _Two  0 to 15%, GeO _Two  0 <~ 50%, TiO _Two  0 to <50%, However, GeO _Two + TiO _Two  25-50%, ZrO _Two  0-10%, M _Two O _Three  0.5 to 15%, However, M = one or two selected from Al and Ga Li _Two 0 10 to 25%, The raw glass containing the composition in the range of
Through the process, Li _{1 + X} M _X (Ge _1-Y Ti _Y ) _2-X (P
O _Four ) _Three (0 <X ≦ 0.8, 0 ≦ Y <1.0)
Lithium ion conductive glass ceramic obtained
And the raw glass is B, In, Sc, Fe, C
trivalent metals such as r (except Al and Ga) and Mg, C
The amount of divalent metal such as a, Sr, Ba, Zn is 10 mol%
A lithium ion conductive glass characterized by the following:
Ceramics. 4. In mol%, P ₂ O ₅ 35 to 40%, SiO ₂ 0 to 15%, GeO ₂ 0 <to 45%, TiO ₂₀ to <45%, provided that GeO ₂ + TiO ₂ 25 to 45 _{%, ZrO 2 0 ~ 10%} , Al 2 O 3 0.5 ~ 15%, Li 2 0 10 ~ 25%, a raw glass containing the composition in the range of, after melt molding, through a heat treatment process, Li _{1 + X} Al _X (Ge _1-Y Ti _Y ) _2-X (PO
_{4) 3} (0 <a X ≦ 0.8,0 ≦ Y <1.0), wherein Rukoto obtained to precipitate a crystalline phase, as claimed in claim 1 to 3 <br /> lithium ion conductivity Glass ceramics. 5. In mol%, P ₂ O ₅ 35 to 40%, SiO ₂ 0 to 15%, GeO ₂ 0 <to 45%, TiO ₂ 0 to <45%, provided that GeO ₂ + TiO ₂ 25 to 45 _{%, ZrO 2 0 ~ 10%} , Ga 2 O 3 0.5 ~ 15%, Li 2 0 10 ~ 25%, a raw glass containing the composition in the range of, after melt molding, through a heat treatment process, Li _{1 + X} Ga _X (Ge _1-Y Ti _Y ) _2-X (PO
_{4) 3 (0 <X ≦} 0.8,0 ≦ Y <1.0) , characterized in Rukoto obtained to precipitate a crystal phase, lithium ion conductive glass ceramics according to claims 1 3. 6. A lithium ion conductive glass ceramic according to claim 1, wherein the lithium ion conductive glass ceramic is used.
Solid electrolyte for lithium batteries. Characterized by using the 7. lithium ion conductive glass ceramics according to claims 1 to 3,
Solid electrolyte for gas sensors. 8. A lithium battery, wherein the lithium ion conductive glass ceramic according to claim 1 is used as a solid electrolyte. 9. A gas sensor using the lithium ion conductive glass ceramic according to claim 1 as a solid electrolyte.