JP2004193112A - Solid electrolyte and all-solid battery using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress deterioration of charge / discharge characteristics, storage characteristics, charge / discharge cycle characteristics, etc. due to reduction of phosphorus atoms in a secondary battery using a solid electrolyte composed of lithium nitride phosphate.
SOLUTION: A solid electrolyte is constituted by incorporating a transition metal element into lithium nitride phosphate. The transition metal element is at least one selected from the following group: Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo Ru, Ag, Ta, W, Pt, Au The content of metal element is 1 to 50 atomic% based on phosphorus atom.

Description

  The present invention relates to an all solid state battery, particularly to a solid electrolyte used for an all solid state thin film lithium secondary battery.

  In recent years, with the development of portable devices such as personal computers and mobile phones, the demand for batteries as power sources has become extremely large. In particular, lithium secondary batteries have been actively studied in various fields as batteries capable of obtaining a high energy density because lithium has a small atomic weight and a large ionization energy.

  In the batteries used for these applications, since a liquid is used for the electrolyte, it is difficult to completely solve problems such as electrolyte leakage. Further, regarding the lithium secondary battery, since the energy density is high, the battery may generate heat when an abnormality occurs in the battery. Therefore, it is necessary that the electrolyte be nonflammable.

  One solution to these problems is an all-solid battery that uses a solid electrolyte instead of a liquid electrolyte. Since all components of the battery are solid, not only the reliability of the battery is improved, but also the battery can be made smaller and thinner. Therefore, even in the case of a lithium secondary battery, development of an all-solid lithium secondary battery that is an all-solid battery using a solid electrolyte composed of a non-combustible solid material is desired.

As a solid electrolyte used in an all-solid lithium secondary battery, for example, lithium halide, lithium nitride, lithium oxyacid salt, and derivatives thereof are known. In particular, lithium nitride phosphate (Li _x PO _y N _z : x = 2.8, 3z + 2y = 7.) Obtained by introducing nitrogen N into lithium orthophosphate (Li ₃ PO ₄ ) reported in Patent Document 1. 8) has an extremely high Li ion conductivity of 1 to 2 × 10 ⁻⁶ S / cm irrespective of the oxide-based material. It is used for all-solid-state thin-film lithium secondary batteries, which are power supplies for micro devices such as electronic tags.
U.S. Pat. No. 5,597,660

However, lithium nitrate phosphate (Li _x PO _y N _z ), which is a solid electrolyte described in Patent Document 1, reacts with moisture and deteriorates when left in a humid atmosphere, resulting in a significant decrease in ionic conductivity. There is a problem of doing. This deterioration originated from the reduction of the phosphorus atom (P) from +5 and the decomposition of lithium nitride phosphate.

  When such deterioration occurs, in the all-solid lithium secondary battery, the electrochemical characteristics such as charge / discharge characteristics, storage characteristics, and charge / discharge cycle characteristics deteriorate. Therefore, an object of the present invention is to provide a solid electrolyte which suppresses the reduction of phosphorus atoms in lithium nitride phosphate as much as possible and is hardly deteriorated.

  In order to solve the above-mentioned problems, the present invention provides a solid electrolyte comprising lithium phosphate and a transition metal element (atom).

The transition metal element is at least one selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Ag, Ta, W, Pt, and Au. It is preferred that
The content of the transition metal element is preferably 1 to 50 atomic% based on phosphorus atoms.

  Further, the present invention also relates to an all solid state battery using the above solid electrolyte.

  According to the present invention as described above, by using a solid electrolyte made of lithium nitride phosphate containing a transition metal, it is possible to suppress electrochemical property deterioration in a humid atmosphere.

The solid electrolyte according to the present invention is configured such that lithium nitride phosphate (Li _x PO _y N _z ) contains a transition metal element T. Therefore, the solid electrolyte according to the present invention has the formula (1):
Li _a PO _b N _c -T _d (1)
(Where a = 2.6 to 3.0, b = 3.0 to 4.0, c = 0.1 to 0.6, d = 0.01 to 0.50).

  Here, in the solid electrolyte represented by the formula (1), the valences of lithium atom (Li), phosphorus atom (P), oxygen atom (O) and nitrogen atom (N) are +1 valence, +5 valence, respectively. They are -2 and -3. Since the transition metal element T is incorporated in the lithium nitride phosphate in a metal state, it can be regarded as having zero valence.

In the solid electrolyte according to the present invention, the transition metal element may be contained in lithium nitride phosphate (Li _x PO _y N _z ) in a state of a compound such as a transition metal oxide or a transition metal nitride.

When the transition metal element is present as a transition metal oxide, the solid electrolyte according to the present invention has the formula (2):
_{Li a PO b N c -T d} O e (2)
(Where a = 2.6-3.0, b = 3.0-4.0, c = 0.1-0.6, d = 0.01-0.50, e = 0.005- 0.175).

When the transition metal element is present as a transition metal nitride, the solid electrolyte according to the present invention has the formula (3):
_{Li a PO b N c -T d} N e (3)
(Where a = 2.6-3.0, b = 3.0-4.0, c = 0.1-0.6, d = 0.01-0.50, e = 0.003- 0.12).

  If the solid electrolyte made of lithium nitride phosphate alone is left in a humid atmosphere, it easily reacts with moisture to cause deterioration, resulting in reduced ionic conductivity. This is because some phosphorus atoms (P) contained in lithium nitride phosphate are reduced from +5 valence during the production of the lithium nitride phosphate thin film.

  On the other hand, in the solid electrolyte according to the present invention, by including the transition metal element, the transition metal element having a higher reducing property than the phosphorus atom (P) and capable of easily changing the valence is preferentially used. Is reduced to Thereby, the phosphorus atoms in the lithium nitride phosphate can be maintained in a +5 valence state.

  The solid electrolyte according to the present invention made of lithium nitride phosphate containing a transition metal element can be manufactured by a thin film manufacturing method using a vacuum device, similarly to conventional lithium nitride phosphate. Of course, a method other than the manufacturing method using a vacuum device may be used.

  As a typical method for manufacturing a thin film using a vacuum apparatus, a method in which a vapor deposition method and ion beam irradiation for introducing nitrogen ions are combined is exemplified. Examples of the vapor deposition method include a sputtering method in which a target is sputtered with nitrogen (N2) by means of a magnetron or a high frequency wave, a resistance heating vapor deposition method in which a vapor deposition source is heated and vapor-deposited by a resistor, and a vapor deposition source which is heated by an electron beam. Examples include an electron beam evaporation method for vapor deposition, and a laser ablation method for vapor deposition by heating a vapor deposition source with a laser.

Here, in order to produce the solid electrolyte according to the present invention, it is necessary to use a target or a vapor deposition source for introducing a transition metal element other than lithium orthophosphate (Li ₃ PO ₄ ) as the target or the vapor deposition source. is there.

  That is, for example, in the case of a sputtering method, a lithium orthophosphate target and a transition metal element target are used. In the case of, for example, a resistance heating evaporation method, an electron beam evaporation method, or a laser ablation method, a lithium orthophosphate evaporation source and a transition metal evaporation source are used. However, it is also possible to use a target or an evaporation source in which a transition metal element is mixed at a predetermined mixing ratio with a lithium orthophosphate target or an evaporation source.

  Further, the evaporation can be performed by combining two kinds of evaporation methods, a resistance heating evaporation method using lithium phosphate as an evaporation source and an electron beam evaporation method using a transition metal as an evaporation source.

  Further, the transition metal element T may be used as an evaporation source as it is, but as the transition metal evaporation source, for example, a transition metal oxide or a transition metal nitride is used for evaporation, and the transition metal element Alternatively, it may be introduced as a nitride. In particular, since the transition metal element is already oxidized in the transition metal oxide, it is very easy to be reduced, which is convenient.

  Typical examples of the transition metal element T here include titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), and copper. (Cu), zirconium (Zr), niobium (Nb), molybdenum (Mo), ruthenium (Ru), silver (Ag), tantalum (Ta), tungsten (W), platinum (Pt), gold (Au), etc. Is mentioned. Of course, other transition metal elements can be used as long as the effects of the present invention are not impaired. The transition metal element to be contained is not limited to one kind, but may be two or more kinds.

  The content of the transition metal element T in the solid electrolyte according to the present invention is desirably 1 to 50 atomic% with respect to phosphorus atoms (P) in lithium nitride phosphate constituting the solid electrolyte.

If the amount is less than 1 atomic%, the reduction of phosphorus atoms cannot be sufficiently suppressed, and if it exceeds 50 atomic%, the skeleton structure of lithium nitride phosphate is broken. This is because the ionic conductivity of the solid electrolyte may decrease and the electron conductivity may increase. When a solid electrolyte with increased electron conductivity is used for a solid electrolyte layer of a thin-film secondary battery, there is a problem that the solid electrolyte layer tends to self-discharge in a charged state.
Further, the solid electrolyte according to the present invention is preferably in the form of a thin film, and the film thickness can be appropriately controlled, but is preferably 0.1 to 10 μm.

  FIG. 2 shows a configuration of a typical all solid-state thin film lithium secondary battery as an all solid state battery including the solid electrolyte according to the present invention. This battery includes a first current collector 22, a first electrode 23, a solid electrolyte 24, a second electrode 25, and a second current collector 26 on a substrate 21. Although the first electrode is a positive electrode layer and the second electrode is a negative electrode layer here, the first electrode may be a negative electrode layer and the second electrode may be a positive electrode layer.

  In this battery, a first current collector 22, a first electrode 23, a solid electrolyte 24, a second electrode 25, and a second current collector 26 were stacked in this order from a substrate 21 by a thin film manufacturing method using a vacuum device. Things. Of course, a method other than the method for producing a thin film using a vacuum device may be used. Further, it is effective to use a resin or an aluminum laminate film on the second current collector 26 as a protective layer of the battery. The thickness of the protective layer is usually 10 μm or more. It is possible to reduce the thickness to a state where there is no.

  As the substrate 21, an electrically insulating substrate such as alumina, glass, and a polyimide film, a semiconductor substrate such as silicon, and a conductive substrate such as aluminum and copper can be used. Here, since it is better that the surface roughness of the surface of the substrate is small, it is useful to use a mirror surface plate or the like. When a semiconductor substrate such as silicon is used, other electric elements such as a display element and a memory element may be simultaneously formed and wired in the semiconductor substrate.

  As the first current collector 22 to be first manufactured on the substrate 21, a material having electron conductivity such as platinum, platinum / palladium, gold, silver, aluminum, copper, or ITO (indium-tin oxide film) is used. . As a current collector, a material other than the above materials may be used as long as it has electron conductivity and does not react with the first electrode. Examples of a method for manufacturing the first current collector include a sputtering method, a resistance heating evaporation method, an ion beam evaporation method, and an electron beam evaporation method. However, when a conductive material such as aluminum, copper, or stainless steel is used for the substrate 21, the first current collector 22 is not required.

The positive electrode layer serving as the first electrode 23 is not limited as long as it is a material used as a positive electrode active material of a lithium secondary battery. In particular, lithium cobalt oxide (LiCoO ₂ ), lithium nickel oxide (LiNiO ₂ ), lithium manganate (LiMn ₂ O ₄ ), or vanadium oxide (V ₂ ), which is a transition metal oxide, currently used for a positive electrode of a lithium secondary battery. O ₅ ), molybdenum oxide (MoO ₃ ), and titanium sulfide (TiS ₂ ) are preferably used. As a method for manufacturing the positive electrode, a sputtering method, a resistance heating evaporation method, an ion beam evaporation method, an electron beam evaporation method, a laser ablation method, a chemical vapor deposition method, or the like can be used.

As described above, a solid electrolyte composed of lithium nitride phosphate (Li _x PO _y N _z ) and the transition metal element T is used as the solid electrolyte 24.

  The negative electrode layer serving as the second electrode 25 is not limited as long as it is a material used as a negative electrode active material of a lithium secondary battery. In particular, carbon materials (C) such as graphite and hard carbon currently used for a negative electrode of a lithium secondary battery, tin alloy (Sn), lithium cobalt nitride (LiCoN), lithium metal (Li) or lithium alloy (for example, , LiAl) or the like. As a method for manufacturing the negative electrode, a sputtering method, a resistance heating evaporation method, an ion beam evaporation method, an electron beam evaporation method, a laser ablation method, or the like can be used.

  As the second current collector 26, similarly to the first current collector 22, a material having electron conductivity such as platinum, platinum / palladium, gold, silver, aluminum, copper, ITO, or a carbon material is used. As a current collector, a material other than the above-mentioned materials may be used as long as it has electron conductivity and does not react with the solid electrolyte 24 or the second electrode 25. As a method for manufacturing the second current collector 26, a sputtering method, a resistance heating evaporation method, an ion beam evaporation method, an electron beam evaporation method, or the like can be used.

  It is also possible to stack a plurality of such all solid state batteries.

Further, the configuration of a typical all solid-state thin film lithium secondary battery has been described as an all solid state battery including the solid electrolyte according to the present invention, but the present invention is not limited to this all solid state thin film lithium secondary battery.
Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited thereto.

<< Examples 1 to 16 and Comparative Example 1 >>
In order to evaluate the effect of the transition metal element in the solid electrolyte according to the present invention, as described below, a solid electrolyte thin film (Li _2.8 PO _3.45 N _0.3 -T _0.2 ) made of lithium nitride phosphate containing a transition metal element Was prepared. In addition, an experimental cell including the obtained solid electrolyte thin film as a solid electrolyte layer was manufactured.

  FIG. 1 shows a schematic cross-sectional view of an experimental cell manufactured in this example. As shown in FIG. 1, the experimental cell was composed of a silicon substrate 11, a platinum current collector layer 12, a solid electrolyte layer 13, and a platinum current collector layer 14.

  First, as a first step, a metal mask having a window (20 mm × 10 mm) is put on a predetermined position of a mirror-finished silicon substrate 11 having a surface roughness of 30 nm or less and made of platinum by RF magnetron sputtering. A film was formed, and a platinum current collector layer 12 having a thickness of 0.5 μm was formed.

  As a second step, the dimensions of the metal mask were changed to 15 mm × 15 mm, and a lithium nitride phosphate thin film was formed on the platinum current collector layer 12 by RF magnetron sputtering for 2 hours to form a solid having a thickness of 1.0 μm. The electrolyte layer 13 was produced.

At this time, two kinds of lithium orthophosphate and transition metal element T shown in Table 1 were used as targets, and nitrogen (N ₂ ) was used as a sputtering gas. The conditions of the RF magnetron sputtering method were set to a chamber internal pressure of 2.7 Pa, a gas introduction amount of 10 sccm, and a power of 200 w of a lithium orthophosphate target. The RF power of the lithium orthophosphate target and the transition metal element T target was controlled such that the content of the transition metal element with respect to the phosphorus atom was 20 atomic%.

  Thereafter, as a third step, a metal mask having a window of 10 mm × 10 mm is arranged on the solid electrolyte layer 13 so as not to protrude from the solid electrolyte layer 13, and a film made of platinum is formed by RF magnetron sputtering. Then, a platinum current collector layer 14 having a thickness of 0.5 μm was formed.

  A storage test was performed on the experimental cell manufactured by the above method at 20 ° C. for 2 weeks. In the test, the experimental cell was stored in a thermostat at 20 ° C. installed in a room having a relative humidity of 50%.

In order to examine the change over time in the ion conductivity, the AC impedance of the experimental cell was measured immediately after preparation, after storage for 1 day, after storage for 2 days, after storage for 1 week, and after storage for 2 weeks. The AC impedance measurement was performed with an equilibrium voltage of zero, an amplitude of ± 10 mV, and a frequency range from 10 ⁵ Hz to 0.1 Hz. The results are shown in Table 1. In addition, the ionic conductivity was shown as an index with respect to the impedance immediately after preparation of the experimental cell as 100.

From the results shown in Table 1, in the solid electrolyte according to the present invention comprising lithium nitride phosphate containing a transition metal element, no significant change in ionic conductivity due to storage is observed. However, in the conventional solid electrolyte containing no transition metal element, the ionic conductivity is largely reduced by storage.
From the above, it can be seen that it is effective to use the solid electrolyte according to the present invention comprising lithium nitride phosphate containing a transition metal element.

<< Examples 17 to 24 >>
In this example, an experiment was performed in the same manner as in Example 1 except that tungsten (W) was used as a transition metal element and the content of tungsten relative to phosphorus atoms (P) was changed to the value shown in Table 2. A cell was fabricated and evaluated.
The impedance measurement was performed in the same manner as in Example 1 except that the impedance measurement was performed immediately after the production of the experimental cell and after storage for 2 weeks. Further, in order to examine the electron conductivity, a voltage of +1.0 V from the equilibrium voltage was applied to the experimental cell immediately after the fabrication, and the current flowing after one hour was measured. Table 2 shows the electron conductivity ratio, which is the ratio of the electron conductivity to the ionic conductivity. The results are shown in Table 2.

According to the results shown in Table 2, when the content of the transition metal element is 1 atomic% or more, no significant change in ionic conductivity due to storage is observed. However, when the content of the transition metal element is 0.5 atomic%, the ionic conductivity is greatly reduced by storage. When the content of the transition metal element is 50 atomic% or less, the electron conductivity ratio is very low, but when it exceeds 50 atomic%, the electron conductivity ratio becomes large.
From the above, it can be seen that in the solid electrolyte according to the present invention comprising lithium nitride phosphate containing a transition metal element, the content of the transition metal element with respect to phosphorus atoms is preferably 1 to 50 atomic%.

<< Example 25 >>
In this example, an experimental cell was fabricated and evaluated in the same manner as in Example 1, except that zirconium (Zr) was used as the transition metal element. Table 3 shows the results.

From the results shown in Table 3, in the solid electrolyte according to the present invention comprising lithium nitride phosphate containing zirconium as a transition metal element, no significant change in ionic conductivity due to storage is observed.
From the above, it can be seen that it is effective to use the solid electrolyte according to the present invention made of lithium nitride phosphate containing zirconium.

<< Example 26 and Comparative Example 2 >>
In this example, a test battery described below was manufactured to evaluate an all-solid battery using a solid electrolyte containing lithium nitride phosphate and a transition metal element.
In this example, an all-solid-state battery having the configuration shown in FIG. 2 was manufactured. Here, the substrate 21 is a silicon substrate, the first current collector 22 is a current collector layer, the first electrode 23 is a positive electrode layer, the solid electrolyte 24 is a solid electrolyte layer containing lithium nitride phosphate and a transition metal, and the second electrode Reference numeral 25 denotes a negative electrode layer, and second current collector 26 denotes a current collector layer.

  As a first step, a metal mask having windows (20 mm × 12 mm) is placed on necessary portions on a mirror-oxidized mirror-finished silicon substrate 21 having a surface roughness of 30 nm or less, and then a platinum thin film is formed by RF magnetron sputtering. Was formed to form a first current collector layer 22 having a thickness of 0.5 μm.

As a second step, a metal mask is changed to 10 mm × 10 mm, a lithium cobalt oxide (LiCoO ₂ ) thin film is formed on the first current collector layer 22 by RF magnetron sputtering for 2 hours, and a positive electrode layer having a thickness of 1 μm is formed. No. 23 was produced. At this time, argon and oxygen were used as the sputtering gas, the chamber internal pressure was 2.7 Pa, the gas introduction amounts were 7.5 sccm and 2.5 sccm, respectively, and the power of the lithium cobalt oxide target was 200 W.

  Next, as a third step, a metal mask is changed to 15 mm × 15 mm, a lithium nitride phosphate thin film is formed on the positive electrode layer 23 by RF magnetron sputtering for 2 hours, and a solid electrolyte layer 24 having a thickness of 1 μm is formed. did.

At this time, two kinds of lithium phosphate, lithium orthophosphate, and tungsten (W) were used as transition metal elements, and nitrogen (N ₂ ) was used as a sputtering gas. The conditions of the RF magnetron sputtering method were set to a chamber internal pressure of 2.7 Pa, a gas introduction amount of 10 sccm, and a power of lithium orthophosphate target of 200 W. The RF power of the tungsten target was controlled such that the tungsten content relative to the phosphorus atoms was 20 atomic%. Here, Comparative Example 2 was performed without using tungsten.

  As a fourth step, the metal mask was changed to 10 mm × 10 mm, and a lithium metal thin film was formed on the solid electrolyte layer 24 by a resistance heating vapor deposition method to produce a negative electrode layer 25 having a thickness of 0.5 μm.

  Thereafter, as a fifth step, the metal mask was changed to 20 mm × 12 mm, and a copper thin film was formed on the negative electrode layer by RF magnetron sputtering so as to completely cover the negative electrode layer 25 without contacting the first current collector layer 22. The second current collector layer 26 having a thickness of 1.0 μm was formed.

  The test battery produced by the above method was subjected to a two-week storage test. In the test, the test batteries were stored in a 20 ° C. constant temperature bath installed in a room where the relative humidity was 50%.

In order to evaluate the improvement in water resistance, the test battery was subjected to AC impedance measurement immediately after the production and after storage for 2 weeks. The AC impedance measurement was performed using an amplitude of ± 10 mV and a frequency range from 10 ⁵ Hz to 0.1 Hz with the balanced voltage set to zero, and the internal impedance of the test battery was determined from the results. The results are shown in Table 4. The internal impedance was shown as an index with respect to the impedance immediately after the production of the test battery as 100.

  From the results shown in Table 4, in the test battery using the solid electrolyte according to the present invention containing lithium nitride phosphate and the transition metal oxide, no significant change in the internal impedance due to storage was observed. However, in a test battery using a conventional solid electrolyte containing no transition metal element, the internal impedance is increased because the solid electrolyte is deteriorated by storage.

  From the above, it can be seen that the all-solid-state battery using the solid electrolyte according to the present invention containing lithium nitride phosphate and the transition metal element is effective in a humid atmosphere. Therefore, by using the solid electrolyte of the present invention, it becomes possible to obtain an all-solid battery that does not require a commonly used protective film. Further, it is possible to form and wire other electric elements in the silicon substrate.

<< Examples 27-44 >>
In this example, molybdenum (Mo), titanium (Ti), and zirconium (Zr) were used as transition metal elements, respectively, and the contents of molybdenum, titanium, and zirconium with respect to the phosphorus atom (P) are shown in Tables 5 to 7. An experimental cell was prepared and evaluated in the same manner as in Example 1 except that the value was changed.
The impedance measurement was performed in the same manner as in Example 1 except that the impedance measurement was performed immediately after the production of the experimental cell and after storage for 2 weeks. Further, in order to examine the electron conductivity, a voltage of +1.0 V from the equilibrium voltage was applied to the experimental cell immediately after the fabrication, and the current flowing after one hour was measured. Tables 5 to 7 show the electron conductivity ratio, which is the ratio of the electron conductivity to the ionic conductivity. The results are shown in Tables 5 to 7, respectively.

According to the results shown in Tables 5 to 7, when the content of the transition metal element is 1 atomic% or more, no significant change in ionic conductivity due to storage is observed. However, when the content of the transition metal element is 0.5 atomic%, the ionic conductivity is greatly reduced by storage. When the content of the transition metal element is 50 atomic% or less, the electron conductivity ratio is very low, but when it exceeds 50 atomic%, the electron conductivity ratio becomes large.
From the above, it can be seen that in the solid electrolyte according to the present invention comprising lithium nitride phosphate containing a transition metal element, the content of the transition metal element with respect to phosphorus atoms is preferably 1 to 50 atomic%.

  If the solid electrolyte according to the present invention is used, an all-solid-state battery having a high energy density suitable for a power supply of a portable device such as a personal computer and a mobile phone, an ultra-small device such as an IC card or an electronic tag, especially an all-solid-state thin film lithium secondary battery You can get a battery.

FIG. 2 is a schematic sectional view of an experimental cell manufactured in an example of the present invention. It is a schematic sectional view of a test battery in the present invention.

Explanation of reference numerals

Reference Signs List 11 silicon substrate 12 platinum current collector layer 13 solid electrolyte layer 14 platinum current collector layer 21 substrate 22 first current collector 23 first electrode 24 solid electrolyte 25 second electrode 26 second current collector

Claims (4)

  A solid electrolyte comprising lithium nitride phosphate containing a transition metal element.   The transition metal element is at least one selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Ag, Ta, W, Pt, and Au. The solid electrolyte according to claim 1, wherein:   3. The solid electrolyte according to claim 1, wherein the content of the transition metal element is 1 to 50 atomic% based on phosphorus atoms.   An all-solid battery comprising the solid electrolyte according to claim 1.

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