JP2021026836A - Positive electrode mixture material - Google Patents

Abstract

To provide a positive electrode mixture material capable of improving the discharge capacity of a battery.SOLUTION: A positive electrode mixture material for an all-solid-state battery includes: a positive active material having S element; a sulfur-containing compound having a P element and an S element; a lithium halide represented by LiX (X is at least one halogen element selected from the group consisting of F, Cl and Br); and a conductive aid, in which the molar ratio of the lithium halide to the sulfur-containing compound is 0.21 to 0.44.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to a positive electrode mixture.

With the rapid spread of information-related devices such as personal computers, video cameras and mobile phones, and communication devices in recent years, the development of batteries used as their power sources has been emphasized. In addition, the automobile industry and the like are also developing high-output and high-capacity batteries for electric vehicles or hybrid vehicles.
Development of a lithium-sulfur battery using sulfur as a positive electrode active material is underway. Sulfur has a characteristic that the theoretical capacity is as high as 1675 mAh / g. Further, in the field of lithium-sulfur batteries, attempts have been made to improve the utilization rate of sulfur and increase the charge / discharge capacity of lithium-sulfur batteries.

Patent Document 1 discloses a positive electrode mixture capable of improving the utilization rate of sulfur and increasing the charge / discharge capacity of a sulfur battery.

Patent Document 2 describes a positive electrode combination that can be suitably used for the positive electrode mixture layer of an all-solid-state lithium-sulfur battery that maximizes the excellent physical properties of sulfur and has an excellent charge / discharge capacity per positive electrode mixture. The material is disclosed.

Japanese Unexamined Patent Publication No. 2019-033067 Japanese Unexamined Patent Publication No. 2015-176849

Higher capacity batteries are required. This disclosure has been made in view of the above circumstances.
The main purpose is to provide a positive electrode mixture capable of improving the discharge capacity of a battery.

In the present disclosure, it is represented by a positive electrode active material having an S element, a sulfur-containing compound having a P element and an S element, and LiX (X is at least one halogen element selected from the group consisting of F, Cl and Br). Contains lithium halide and a conductive additive,
Provided is a positive electrode mixture for an all-solid-state battery, characterized in that the molar ratio of the lithium halide to the sulfur-containing compound is 0.21 to 0.44.

The present disclosure can provide a positive electrode mixture capable of improving the discharge capacity of a battery.

It is sectional drawing which shows an example of the all-solid-state battery used in this disclosure. It is a graph which shows the relationship between the mol ratio of LiX to the sulfide-containing substance and the discharge capacity of the all-solid-state battery at 1C rate.

In the present disclosure, it is represented by a positive electrode active material having an S element, a sulfur-containing compound having a P element and an S element, and LiX (X is at least one halogen element selected from the group consisting of F, Cl and Br). Contains lithium halide and a conductive additive,
Provided is a positive electrode mixture for an all-solid-state battery, characterized in that the molar ratio of the lithium halide to the sulfur-containing compound is 0.21 to 0.44.

As positive electrode material for all-solid-state battery, comprising a cathode active material having a S element as a substitute for expensive lithium sulfide (Li 2 _S), a sulfur-containing compound having a P element and S elements, and a conductive additive When Li is inserted into the mixed material, the ionic conductivity of the mixed material in the state where Li is inserted is low, so that there is a problem that it is difficult to discharge at a high current after the initial charge of the battery. By adding a specific lithium halide to the mixture, the researchers can improve the ionic conductivity of the mixture and improve the discharge capacity of the battery (particularly the discharge capacity at 1 C rate). I found.

1. 1. Positive electrode active material The positive electrode active material has an S element. Various materials can be adopted as the positive electrode active material having the S element. For example, the positive electrode active material may be elemental sulfur. The elemental sulfur include, for example, S ₈ sulfur. S ₈ sulfur, alpha sulfur (rhombic sulfur), beta sulfur (monoclinic sulfur), gamma sulfur may have three crystalline form of (monoclinic sulfur), but may be any crystalline form.

The amount of the positive electrode active material contained in the positive electrode mixture is not particularly limited, and may be appropriately determined according to the target battery performance. For example, the positive electrode mixture may contain 10% by mass or more and 80% by mass or less of the positive electrode active material. The lower limit may be 15% by mass or more, 20% by mass or more, or 25% by mass or more. The upper limit may be 70% by mass or less, or 60% by mass or less. If the content of the positive electrode active material is too large, the ionic conductivity and the electron conductivity in the positive electrode layer of the battery may be insufficient.

A part or all of the positive electrode active material may be dissolved in a sulfur-containing compound described later. In other words, the positive electrode mixture may contain a solid solution of the positive electrode active material and the sulfur-containing compound. Further, the S element in the positive electrode active material and the S element in the sulfur-containing compound may have a chemical bond (SS bond).

2. 2. Sulfur-containing compound The positive electrode mixture in the present disclosure contains at least a sulfur-containing compound having a P element and an S element as a sulfur-containing compound. The positive electrode mixture may contain only a sulfur-containing compound having a P element and an S element, and further contains a sulfur-containing compound having another element (for example, Ge, Sn, Si, B or Al) and an S element. It may be contained. In the latter case, the positive electrode mixture may contain a sulfur-containing compound having a P element and an S element as the main component of the sulfur-containing compound. Specifically, the total amount of the sulfur-containing compound contained in the positive electrode mixture may be 100% by mass, and the sulfur-containing compound having P element and S element may be contained in an amount of 50% by mass or more and 100% by mass or less.

When the battery is discharged, Li ions are conducted from the negative electrode layer to the positive electrode layer via the solid electrolyte layer, but the Li ions that reach the positive electrode layer react with the positive electrode active material and discharge products with low ionic conductivity (for example,). , it may result in _Li 2 S). Therefore, when the sulfur-containing compound is not present in the positive electrode layer, the ionic conductivity of the discharge product is low, so that the ionic conduction path in the positive electrode layer is insufficient, and the discharge reaction may be difficult to proceed. On the other hand, when the sulfur-containing compound is present in the positive electrode layer, the discharge reaction proceeds because the sulfur-containing compound secures an ion conduction path in the positive electrode layer even if the ionic conductivity of the discharge product is low. Cheap.

The sulfur-containing compound can take various forms in the positive electrode mixture. For example, the positive electrode mixture may contain a sulfur-containing compound having a structure having an ortho composition. That is, the sulfur-containing compound may have an ortho structure of P element. Specifically, the ortho structure of the P element is a PS ₄ structure.
Further, the sulfur-containing compound may have an ortho structure of an M element (M is, for example, Ge, Sn, Si, B or Al). Examples of the ortho structure of the M element include a GeS ₄ structure, a SnS ₄ structure, a SiS ₄ structure, a BS ₃ structure, and an AlS ₃ structure.
On the other hand, sulfur-containing compounds, it may contain sulfide P element (e.g. P _{2 S 5).}
Further, the sulfur-containing compound may have a sulfide of M element (M _x S _y ). Here, x and y are integers that give electrical neutrality to S depending on the type of M. Examples of the sulfide (M _x S _{y ) include GeS 2} , SnS ₂ , SiS ₂ , B ₂ S ₃ , and Al ₂ S ₃ . Further, these sulfides may be, for example, residues of starting materials.

Further, as described above, the S element in the sulfur-containing compound and the S element in the positive electrode active material may have a chemical bond (SS bond). In particular, it is preferable that the S element in the ortho structure and the S element in the positive electrode active material have a chemical bond (SS bond).
The amount of the sulfur-containing compound contained in the positive electrode mixture is not particularly limited, and may be appropriately determined according to the target battery performance. For example, the positive electrode mixture may contain a sulfur-containing compound in an amount of 10% by mass or more and 80% by mass or less. The lower limit may be 15% by mass or more, 20% by mass or more, or 25% by mass or more. The upper limit may be 70% by mass or less, or 60% by mass or less. If the content of the sulfide-containing substance is too large, the content of the positive electrode active material is relatively small, and a positive electrode mixture having a sufficient capacity may not be obtained.

3. 3. Conductive Auxiliary Agent The conductive auxiliary agent has a function of improving the electronic conductivity of the positive electrode mixture. Further, it is presumed that the conductive auxiliary agent functions as a reducing agent that reduces elemental sulfur (positive electrode active material), for example, when mechanical milling is performed on a raw material mixture. The conductive auxiliary agent may be dispersed in the positive electrode mixture.

Examples of the conductive auxiliary agent include carbon materials and metal materials. Examples of the carbon material include vapor-grown carbon fiber (VGCF), acetylene black, activated carbon, furnace black, carbon nanotubes, ketjen black, graphene and the like. In the positive electrode mixture, two or more kinds of conductive auxiliaries may be mixed and used.
The amount of the conductive auxiliary agent contained in the positive electrode mixture is not particularly limited, and may be appropriately determined according to the target battery performance. For example, the positive electrode mixture may contain 5% by mass or more and 50% by mass or less of the conductive auxiliary agent. The lower limit may be 10% by mass or more. The upper limit may be 40% by mass or less. If the content of the conductive auxiliary agent is too large, the content of the positive electrode active material is relatively small, and a positive electrode mixture having a sufficient capacity may not be obtained.

4. Lithium Halogenate Lithium halide may be at least one lithium halide selected from the group consisting of LiF, LiCl and LiBr, and may be at least one of LiCl and LiBr.
In the positive electrode mixture, the molar ratio of lithium halide to the sulfur-containing compound in the positive electrode mixture is 0.21 to 0.44. By containing lithium halide within the above range in the positive electrode mixture, the ionic conductivity of the positive electrode mixture can be improved and the discharge capacity of the battery can be improved.

5. Positive Electrode Mixture The positive electrode mixture in the present disclosure may contain only a positive electrode active material, a sulfur-containing compound, lithium halide and a conductive auxiliary agent, and may further contain other materials such as a binder.
Examples of the binder include acrylonitrile-butadiene rubber (ABR), butadiene rubber (BR), polyvinylidene fluoride (PVdF), styrene-butadiene rubber (SBR), and the like. The content of the binder in the positive electrode mixture is not particularly limited.
The shape of the positive electrode mixture may be powdery, agglomerates formed by aggregating and bonding a plurality of particles, or other shapes. Various shapes can be adopted depending on the form of the target battery and the like.

6. Method for Producing Positive Electrode Mixture The method for producing a positive electrode mixture in the present disclosure is at least (1) from a positive electrode active material having an S element, a sulfur-containing compound having a P element and an S element, and LiX (X is F, Cl and Br). A preparatory step for preparing a raw material containing lithium halide and a conductive auxiliary agent represented by (at least one halogen element selected from the above group), and (2) a mixing step for mixing the raw materials to obtain a positive electrode mixture. Has.

(1) Preparation step In the preparation step, a positive electrode active material having an S element, a sulfide containing a P element and an S element, and LiX (X is at least one halogen element selected from the group consisting of F, Cl and Br). This is a step of preparing a raw material containing lithium halide represented by) and a conductive auxiliary agent. The raw material may be produced by oneself or purchased from another person.

The raw material may contain only the positive electrode active material, the sulfide-containing substance, lithium halide and the conductive auxiliary agent, and may further contain other materials.

As described above, the positive electrode active material may be elemental sulfur. Elemental sulfur preferably has high purity.
The sulfur-containing compound, for _example, P 2 _{S 5.} The raw material may contain only the sulfide-containing substance of the P element as the sulfide-containing substance, or may further contain the sulfide-containing substance of another element. Examples of sulfide-containing substances of other elements include GeS ₂ , SnS ₂ , SiS ₂ , B ₂ S ₃ , and Al ₂ S ₃ . The raw material may contain only one type of sulfide containing other elements, or may contain two or more types.
The lithium halide and the conductive auxiliary agent are as described above, and the description thereof will be omitted here.

The contents of the positive electrode active material, the sulfide-containing substance, the lithium halide and the conductive auxiliary agent in the raw material are the same as the contents of the positive electrode active material, the sulfide-containing substance, the lithium halide and the conductive auxiliary agent in the above-mentioned positive electrode mixture. Can be a quantity.

(2) Mixing Step The mixing step is a step of mixing the raw materials to obtain a positive electrode mixture. The means for mixing the raw materials is not particularly limited. For example, the raw materials may be mixed by mechanical milling. Mechanical milling makes it easier to amorphize the raw material.

The mechanical milling is not particularly limited as long as it is a method of mixing the positive electrode mixture while applying mechanical energy, and examples thereof include a ball mill, a vibration mill, a turbo mill, a mechanofusion, and a disc mill. From the viewpoint of facilitating the amorphization of the raw material, a planetary ball mill may be adopted.

The mechanical milling may be a dry mechanical milling or a wet mechanical milling. Examples of the liquid used for wet mechanical milling include those having an aprotic property such that hydrogen sulfide is not generated. Specific examples thereof include aprotic liquids such as polar aprotic liquids and non-polar aprotic liquids.

The conditions for mechanical milling are appropriately set so as to obtain a desired positive electrode mixture. For example, when a planetary ball mill is used, the raw material mixture and the crushing balls are added to the container, and the treatment is performed at a predetermined base rotation speed and time. The base rotation speed may be, for example, 200 rpm or more, 300 rpm or more, or 500 rpm or more. On the other hand, the rotation speed of the base plate is, for example, 800 rpm or less, and may be 600 rpm or less. The processing time of the planetary ball mill is, for example, 30 minutes or more, and may be 5 hours or more. On the other hand, the processing time of the planetary ball mill is, for example, 100 hours or less, and may be 60 hours or less. Examples of the material of the container and the crushing ball used in the planetary ball mill include ZrO ₂ and Al ₂ O ₃ . The diameter of the crushing ball is, for example, 1 mm or more and 20 mm or less. Mechanical milling is preferably performed in an inert gas atmosphere (for example, Ar gas atmosphere).

7. All-solid-state battery FIG. 1 is a schematic cross-sectional view showing an example of an all-solid-state battery used in the present disclosure.
As shown in FIG. 1, the all-solid-state battery 100 includes a positive electrode 16 including a positive electrode layer 12 and a positive electrode current collector 14, a negative electrode 17 including a negative electrode layer 13 and a negative electrode current collector 15, and a positive electrode layer 12 and a negative electrode layer 13. A solid electrolyte layer 11 is provided between the two.

The positive electrode layer is made of the above-mentioned positive electrode mixture.
The thickness of the positive electrode layer is not particularly limited, but may be, for example, 0.1 μm or more and 1000 μm or less.
The basis weight of the positive electrode layer is not particularly limited ^{, but may be, for example, 3 mg / cm 2} or more, 4 mg / cm ² or more, or 5 mg / cm ² or more. There may be.
The positive electrode layer can be easily formed by, for example, pressing the above-mentioned positive electrode mixture.

The negative electrode layer is a layer containing at least a negative electrode active material.
The negative electrode active material may have a Li element. Examples of such a negative electrode active material include elemental lithium or a lithium alloy. Examples of the lithium alloy include a Li-In alloy.
The negative electrode layer may contain at least one of a solid electrolyte, a conductive auxiliary agent and a binder, if necessary. The solid electrolyte may be appropriately selected from the solid electrolytes that can be contained in the solid electrolyte layer described later. The conductive auxiliary agent and the binder may be appropriately selected from the conductive auxiliary agents and the binder that can be contained in the above-mentioned positive electrode mixture.
The thickness of the negative electrode layer is not particularly limited, but may be, for example, 0.1 μm or more and 1000 μm or less.
The negative electrode layer can be easily formed, for example, by pressing the above-mentioned negative electrode active material or the like. Alternatively, a foil made of the above material may be used as the negative electrode layer.

The solid electrolyte layer is a layer containing at least a solid electrolyte, and may contain a binder, if necessary.
Examples of the solid electrolyte include a sulfide-based solid electrolyte, an oxide-based solid electrolyte, a nitride-based solid electrolyte, and a halide-based solid electrolyte. Among them, a sulfide-based solid electrolyte is preferable.
The sulfide-based solid electrolyte preferably has a Li element, an A element (A is at least one of P, Ge, Si, Sn, B and Al), and an S element. The sulfide-based solid electrolyte may further contain a halogen element. Examples of the halogen element include F element, Cl element, Br element and I element, and F element, Cl element and Br element are preferable. Further, the sulfide-based solid electrolyte may further have an O element.
Examples of the sulfide-based solid electrolyte include Li ₂ S-P ₂ S ₅ , Li ₂ S-P ₂ S ₅ -Li I, Li ₂ S-P ₂ S _5- GeS ₂ , Li ₂ S-P ₂ S ₅ -Li ₂ O, Li ₂ S-P ₂ S ₅ -Li ₂ O-LiI, Li ₂ S-P ₂ S ₅ -LiI-LiBr, Li ₂ S-SiS ₂ , Li ₂ S-SiS _2- LiI, Li ₂ S-SiS _2- LiBr, Li ₂ S-SiS _2- LiCl, Li ₂ S-SiS _2- B ₂ S _3- LiI, Li ₂ S-SiS _2- P ₂ S _5- LiI, Li _{2 SB 2} S ₃ , Li ₂ SP ₂ S _{5- Z m} S _n (where m and n are positive numbers; Z is either Ge, Zn or Ga), Li ₂ S-GeS ₂ , Li ₂ S-SiS _{2 -Li 3} PO ₄ , Li ₂ S-SiS _{2 -Li x} MO _y (where x, y are positive numbers, M is P, Si, Ge, B, Al, Ga or In. Either.) Can be mentioned.
As the solid electrolyte, one kind alone or two or more kinds can be used. When two or more kinds of solid electrolytes are used, two or more kinds of solid electrolytes may be mixed, or two or more layers of each solid electrolyte may be formed to form a multilayer structure.
The proportion of the solid electrolyte contained in the solid electrolyte layer is not particularly limited, but may be, for example, 50% by volume or more, 70% by volume or more, or 90% by volume or more. There may be. The binder used for the solid electrolyte layer may be appropriately selected from the binders that can be contained in the above-mentioned positive electrode mixture.
The thickness of the solid electrolyte layer is not particularly limited, but may be, for example, 0.1 μm or more and 1000 μm or less. The solid electrolyte layer can be easily formed, for example, by pressing the above-mentioned solid electrolyte or the like.

Examples of the material of the positive electrode current collector include SUS, aluminum, nickel, iron, titanium and carbon. On the other hand, examples of the material of the negative electrode current collector include SUS, copper, nickel and carbon.
The positive electrode current collector and the negative electrode current collector may be, for example, foil-shaped or mesh-shaped.

The all-solid-state battery includes, if necessary, a positive electrode, a negative electrode, and an exterior body that houses the solid electrolyte layer.
The shape of the exterior body is not particularly limited, and examples thereof include a laminated type.
The material of the exterior body is not particularly limited as long as it is stable to the electrolyte, and examples thereof include resins such as polypropylene, polyethylene, and acrylic resin.

The all-solid-state battery in the present disclosure may be a sulfur battery. The sulfur battery means a battery using elemental sulfur as a positive electrode active material. The all-solid-state battery in the present disclosure may be a lithium-sulfur battery (LiS battery). The all-solid-state battery may be a primary battery or a secondary battery, but the latter is preferable. This is because it can be repeatedly charged and discharged, and is useful as an in-vehicle battery, for example. The secondary battery also includes the use as a primary battery of the secondary battery (use for the purpose of discharging only once after charging).
Examples of the shape of the all-solid-state battery include a coin type, a laminated type, a cylindrical type, and a square type.

The method for producing the all-solid-state battery of the present disclosure is not particularly limited, and a conventionally known method can be adopted.

(Example 1)
(Preparation of positive electrode mixture)
Elemental sulfur S (positive electrode active material, manufactured by Pure _Chemical), P 2 _{S 5} (sulfur-containing compound) was prepared LiBr (lithium halide) and VGCF (conductive additive). These were weighed so as to have the mass ratio shown in Table 1, and each raw material was kneaded in an agate mortar for 15 minutes to obtain a raw material. The obtained raw material was put into a container of a planetary ball mill (45 cc, _{manufactured by ZrO 2} ), and further, a ZrO ₂ ball (φ = 4 mm, 96 g) was put into the container, and the container was completely sealed. This container is attached to a planetary ball mill machine (P7 made by Fritsch), and a cycle of 1 hour mechanical milling (base rotation speed 500 rpm), 15 minutes stop, 1 hour mechanical milling (base plate rotation speed 500 rpm), 15 minutes stop in reverse rotation. Was repeated, and mechanical milling was performed for a total of 48 hours. As a result, a positive electrode mixture was obtained.

(Manufacturing of all-solid-state battery)
100 mg of a solid electrolyte was placed in a 1 cm ^{2 ceramic mold and pressed at 1 ton / cm 2} to obtain a solid electrolyte layer. ^{7.8 mg (weight: 7.8 mg / cm 2} ) of the positive electrode mixture was put on one side thereof and pressed at 6 ton / cm ² to prepare a positive electrode layer. A lithium metal foil, which is a negative electrode layer, was placed on the opposite side thereof ^{and pressed at 1 ton / cm 2} to obtain a power generation element. An Al foil (positive electrode current collector) was placed on the positive electrode layer side, and a Cu foil (negative electrode current collector) was placed on the negative electrode layer side. As a result, an all-solid-state battery was obtained.

[Example 2 and Comparative Examples 1 to 5]
A positive electrode mixture and an all-solid-state battery were obtained in the same manner as in Example 1 except that each raw material was weighed so as to have the mass ratio shown in Table 1. In Comparative Examples 4 to 5, LiI was used instead of LiBr.

(Charge / discharge test)
A charge / discharge test was performed on the all-solid-state batteries obtained in Examples 1 and 2 and Comparative Examples 1 and 5. The charge / discharge test was performed according to the following procedure. The temperature environment is 25 ° C., and 1C corresponds to ^{4.56 mA / cm 2.}
(1) Discharge to 1.5V at 0.1C, pause for 10 minutes (2) Charge to 3.1V at 0.1C, pause for 10 minutes, discharge to 1.5V at 0.1C, pause for 10 minutes, 5 cycles in total (3) Charge to 3.1V at 0.1C, pause for 10 minutes, discharge to 1.5V at 0.33C, pause for 10 minutes, discharge to 1.5V at 0.1C, pause for 10 minutes (4) ) Charge to 3.1V at 0.1C, pause for 10 minutes, discharge to 1.5V at 1C, pause for 10 minutes, discharge to 1.5V at 0.1C, pause for 10 minutes

FIG. 2 shows the relationship between the mol ratio of LiX to the sulfide-containing substance obtained in the above procedure (4) and the discharge capacity of the all-solid-state battery at the 1C rate.
As shown in FIG. 2, by adding LiBr so that the mol ratio to the sulfide-containing substance is 0.21 to 0.44 as compared with Comparative Example 1 in which LiX is not added, the discharge capacity of the battery at 1C It became clear that
This, Br ^- is that incorporated into the structure of P _{2 S} 5 _{(sulfur-containing} compound), Br ^- is considered to have contributed to the improvement of lithium ion conductivity.
On the other hand, in Comparative Examples 2 and 3 in which the mol ratio of LiBr to the sulfide-containing substance exceeded 0.44, the effect of improving the discharge capacity at 1C was not observed.
It the content of LiBr in the positive electrode material is too large, Br to P 2 _S 5 in the structure of _{(sulfur-containing} compound) ^- beyond the solid solubility limit of, LiBr is in the positive-electrode composite as a high resistance element It is thought that this is because it remains.
Further, in Comparative Examples 4 to 5 to which LiI was added, no improvement in the discharge capacity was observed.
This is because the ionic radius of ^{Br −} was about the same as ^{that of S 2-} , while the ionic radius of ^{I −} was larger than that ^{of S 2-,} _{and it went into the structure of P 2} S ₅ (sulfide-containing). This is thought to be because it is difficult to dissolve in solid solution.

As described above, the discharge capacity improving effect by LiX addition, ^{S 2-of} elemental sulfur (positive electrode active material) is in conjunction with the solid solution within the structure of _P 2 _{S 5} (sulfur-containing compound), LiX anionic species It is considered that this contributed to the improvement of the ionic conductivity of the positive electrode mixture by being dissolved in the structure _{of P 2} S _{5 (sulfide-containing sulfide).}
Examples of the LiX species to be added include LiCl and LiF in addition to the above. Table 2 shows the ionic radii of the LiX anion. The ionic radius of Cl ^{− is about the same as that of S 2-,} and it is presumed that the same effect as when LiBr is added can be obtained. Since the ionic radius of ^{F − is smaller than that of S 2-,} it is presumed that the same effect as when LiBr is added can be obtained.

11 Solid electrolyte layer 12 Positive electrode layer 13 Negative electrode layer 14 Positive electrode current collector 15 Negative electrode current collector 16 Positive electrode 17 Negative electrode 100 All-solid-state battery

Claims (1)

A positive electrode active material having an S element, a sulfur-containing compound having a P element and an S element, and lithium halide represented by LiX (X is at least one halogen element selected from the group consisting of F, Cl and Br). , Containing conductive aid,
A positive electrode mixture for an all-solid-state battery, characterized in that the molar ratio of the lithium halide to the sulfur-containing compound is 0.21 to 0.44.