JP6524785B2 - All solid battery - Google Patents

Description

  The present invention relates to, for example, an all-solid-state battery capable of suppressing an increase in battery temperature at the time of a short circuit.

  With the rapid spread of information related devices such as personal computers, video cameras and mobile phones and communication devices in recent years, development of a battery excellent as a power source is regarded as important. In addition, in fields other than information-related equipment and communication-related equipment, for example, in the automobile industry, development of lithium ion batteries as batteries used for electric vehicles and hybrid vehicles is in progress.

Since lithium batteries currently on the market use an electrolytic solution containing a flammable organic solvent, a structure for attachment of a safety device for preventing temperature rise at the time of short circuit and short circuit prevention is required. On the other hand, a lithium battery in which the battery is totally solidified by changing the electrolytic solution to a solid electrolyte layer does not use a flammable organic solvent in the battery, so the safety device can be simplified, and the manufacturing cost and productivity It is considered to be excellent. Furthermore, among the all-solid-state batteries, the all-solid-state battery using a sulfide solid electrolyte material has an advantage of excellent Li ion conductivity.
For example, Patent Document 1 discloses an all-solid battery using a sulfide solid electrolyte material which is a sulfided glass having a high crystallization temperature.

  For example, Patent Document 2 discloses a non-aqueous electrolyte battery having a separator containing an inorganic compound capable of releasing water of crystallization as a technique for suppressing a temperature rise during a short circuit in a lithium battery using an electrolytic solution. ing. Further, Patent Document 3 discloses a non-aqueous electrolyte battery including a gas generating agent on the surface or inside of at least one of a positive electrode active material layer, an electrolyte layer, and a negative electrode active material layer. Patent Document 4 discloses a non-aqueous electrolyte battery having an active material layer containing a material whose electric resistance increases at high temperature.

  Patent Document 5 discloses an all solid battery in which a sulfide solid electrolyte is coated with a liquid substance such as silicone oil. The invention described in Patent Document 5 aims to suppress the generation of hydrogen sulfide. Patent Document 6 discloses a nonflammable solid electrolyte containing a sulfide solid electrolyte and a silicone compound. The invention described in Patent Document 6 aims to provide an essentially noncombustible solid electrolyte.

JP, 2013-037896, A Unexamined-Japanese-Patent No. 2010-073528 JP, 2008-226807, A JP, 2011-029079, A JP, 2009-117168, A JP, 2008-103243, A

In the all-solid-state battery using a sulfide solid electrolyte material, for example, it is required to suppress an increase in battery temperature at the time of a short circuit.
The present invention has been made in view of the above situation, and its main object is to provide an all-solid-state battery capable of suppressing an increase in battery temperature at the time of a short circuit, for example.

  In order to achieve the above object, in the present invention, a sulfide solid electrolyte is formed between a positive electrode layer containing a positive electrode active material, a negative electrode layer containing a negative electrode active material, and the positive electrode layer and the negative electrode layer. A solid electrolyte layer containing a material, wherein the positive electrode layer, the solid electrolyte layer or the negative electrode layer contains an organic material, and the organic material is hydroxylated at a temperature of 80.degree. C. or more An all-solid-state battery is provided, which is a material generating a group or a carbonyl group.

  According to the present invention, when the positive electrode layer, the solid electrolyte layer, or the negative electrode layer contains an organic material, the organic material forms a hydroxyl group or a carbonyl group, for example, when the battery temperature reaches 80 ° C. or more at the time of shorting. Do. By reacting the generated hydroxyl group or carbonyl group with the sulfide solid electrolyte material, the ion conductivity in the layer (for example, the ion conductivity of the solid electrolyte layer) can be decreased to increase the cell resistance. Can. Therefore, the short circuit current can be reduced, and the heat generation due to the short circuit current can be suppressed, so that the rise of the battery temperature can be suppressed.

  The all-solid-state battery of the present invention has an effect of being able to suppress an increase in battery temperature at the time of short circuit, for example.

It is a schematic sectional drawing which shows an example of the all-solid-state battery of this invention. It is explanatory drawing explaining the effect of the all-solid-state battery of this invention. It is a flowchart explaining the generation | occurrence | production process of the malfunction of the battery at the time of the short circuit in the conventional all solid battery, and the process of suppressing the malfunction of the battery at the time of the short circuit in the all solid battery of this invention.

Hereinafter, the details of the all-solid-state battery of the present invention will be described.
FIG. 1 is a schematic cross-sectional view showing an example of the all-solid-state battery of the present invention. The all-solid battery 10 shown in FIG. 1 is formed between a positive electrode layer 1 containing a positive electrode active material, a negative electrode layer 2 containing a negative electrode active material, and a positive electrode layer 1 and a negative electrode layer 2, and a sulfide solid electrolyte material And a solid electrolyte layer 3 containing In addition, the all-solid-state battery 10 generally includes a positive electrode current collector 4 that collects current from the positive electrode layer 1 and a negative electrode current collector 5 that collects current from the negative electrode layer 2. In the present invention, the organic material is characterized in that the material produces a hydroxyl group or a carbonyl group at a temperature of 80 ° C. or more.

  “The organic material produces a hydroxyl group or a carbonyl group” means that the organic material undergoes a chemical reaction such as decomposition to generate (release) a compound having a hydroxyl group or a carbonyl group, or a hydroxyl group Alternatively, it means that an organic material having a carbonyl group undergoes a phase transition such as melting and sublimation. In addition, the organic material may have both the chemical reaction and the phase transition described above.

  According to the present invention, when the positive electrode layer, the solid electrolyte layer, or the negative electrode layer contains an organic material, the organic material forms a hydroxyl group or a carbonyl group, for example, when the battery temperature reaches 80 ° C. or more at the time of shorting. Do. By reacting the generated hydroxyl group or carbonyl group with the sulfide solid electrolyte material, the ion conductivity in the layer (for example, the ion conductivity of the solid electrolyte layer) can be decreased to increase the cell resistance. Can. Therefore, the short circuit current can be reduced, and the heat generation due to the short circuit current can be suppressed, so that the rise of the battery temperature can be suppressed.

  Further, according to the present invention, for example, when the battery temperature becomes equal to or higher than the operating temperature due to a short circuit, it is possible to suppress abnormal heat generation due to a further rise in battery temperature. Here, the operating temperature of the all-solid-state battery is usually less than 80.degree.

  In the conventional all solid-state battery, for example, the reason why the battery temperature rises at the time of short circuit is as follows. That is, compared to the time of normal battery use, a high current starts to flow between the positive electrode layer and the negative electrode layer at the time of short circuit, and Joule heat due to the short circuit is generated. If the high current continues to flow in the all-solid-state battery, the Joule heat generation amount will be large. In addition, the generated heat is accumulated in the all solid battery (Joule heat accumulation). The heat accumulated in this way raises the battery temperature.

  On the other hand, in the all-solid-state battery of the present invention, the positive electrode layer, the solid electrolyte layer or the negative electrode layer is a mixture layer containing an organic material. Such an all-solid-state battery has a higher current (short-circuit current) between the positive electrode layer 1 and the negative electrode layer 2 at the time of a short circuit (FIG. 2 (b)) compared to the normal battery use (FIG. 2 (a)). ) Starts to flow and Joule heat is generated due to the short circuit. However, when the battery temperature reaches 80 ° C. or more, the organic material generates a hydroxyl group or a carbonyl group. By reacting the hydroxyl group or the carbonyl group with the sulfide solid electrolyte material, for example, the ion conductivity of the solid electrolyte layer 3 can be reduced, and the battery resistance of the all-solid battery 10 can be increased (see FIG. 2 (c). In addition, the battery reaction can be suppressed. Therefore, the short circuit current can be reduced, and the Joule heat can be reduced. In addition, the heat accumulated in the all solid battery becomes small, and the rise of the battery temperature can be suppressed.

  As described above, in the conventional all solid-state battery, the battery temperature rises due to heat storage caused by the high current continuing to flow at the time of the short circuit (FIG. 3A). On the other hand, in the all solid battery of the present invention, at the time of a short circuit, a hydroxyl group or a carbonyl group is formed from an organic material at a temperature of 80 ° C. or more, and the battery resistance is increased by reacting with a sulfide solid electrolyte material. It can be done. Therefore, since the short circuit current can be reduced, an increase in battery temperature can be suppressed (FIG. 3 (b)).

  If the battery temperature rises during a short circuit, for example, there is a problem that the decomposition of the solid electrolyte material is caused and the battery performance (capacitance performance and output performance) is degraded.

  Traditionally, all-solid-state batteries are recognized to be safer than liquid-based batteries. In general, all-solid-state batteries have lower battery performance than liquid-based batteries. Therefore, the current situation is that studies on the safety of all solid state batteries have not been sufficiently conducted. On the other hand, since the battery performance of the all solid battery is improved daily, it is necessary to study the safety.

  Hereinafter, the structure of the all-solid-state battery of this invention is demonstrated.

1. Organic Material The organic material used in the present invention is a material that forms a hydroxyl group or a carbonyl group at a temperature of 80 ° C. or higher.
The organic material refers to a material having at least a (-CH-) bond. In addition, the organic material is a material that does not substantially react with the sulfide solid electrolyte material at a temperature of less than 80 ° C. The phrase "does not substantially react" means that the organic material does not react with the sulfide solid electrolyte material to such an extent that the battery reaction of the all solid battery is not inhibited at a temperature of less than 80 ° C.

  The formation temperature of the hydroxyl group or the carbonyl group is usually 80 ° C. or higher, may be 100 ° C. or higher, or may be 120 ° C. or higher. Moreover, as a production | generation temperature of the said hydroxyl group or a carbonyl group, it is 400 degrees C or less, for example.

  The organic material may be a material that generates a compound having a hydroxyl group or a carbonyl group by a chemical reaction such as decomposition at a temperature of 80 ° C. or higher, and is an organic material having a hydroxyl group or a carbonyl group, It may be a material that undergoes a phase transition such as melting or sublimation at a temperature of 80 ° C. or higher.

  As a compound which has a hydroxyl group, alcohol can be mentioned, for example. The alcohol may be, for example, an alcohol having 5 or less carbon atoms, or may be an alcohol having 3 or less carbon atoms. Specific examples of the alcohol include propanol such as methanol, ethanol, 1-propanol, 2-propanol and the like.

  As an organic material which generate | occur | produces alcohol, polyethylene is mentioned as an organic material which generate | occur | produces methanol, for example.

  As a compound which has a carbonyl group, a ketone can be mentioned, for example. The ketone may be, for example, a ketone having 5 or less carbon atoms, or may be a ketone having 3 or less carbon atoms. Examples of such ketones include acetone, methyl ethyl ketone, diethyl ketone and the like.

  As an organic material which generate | occur | produces a ketone, an organic acid salt can be mentioned, for example. Moreover, as an organic acid salt, an acetate and a formate can be mentioned, for example. Moreover, as a metal used for an organic acid salt, an alkaline earth metal can be mentioned, for example. Among the alkaline earth metals, calcium is preferred. As a specific organic material, calcium acetate is mentioned, for example. Calcium acetate produces acetone by heating to 400 ° C. or higher. Moreover, EVA resin (ethylene-vinyl acetate copolymer resin) can be mentioned as an organic material which generate | occur | produces a ketone.

  Moreover, as an organic material which has a hydroxyl group and carries out phase transition, saccharides can be mentioned, for example. Examples of saccharides include xylitol, mannitol, erythritol, and galacitol. For example, mannitol, erythritol, xylitol, and galactose are melted by heating to 95 ° C. or higher.

Moreover, as an organic material which has a carbonyl group and carries out phase transition, saccharides can be mentioned, for example. As saccharides, glucose can be mentioned, for example. For example, glucose melts at 146 ° C.
Moreover, as an organic material which has a carbonyl group and carries out phase transition, oxalic acid dihydrate and malonic acid can be mentioned. For example, oxalic acid dihydrate melts at 101 ° C and malonic acid melts at 135 ° C.

  In the present invention, only one type of the organic material described above may be used, or two or more types may be used in combination. By selecting the organic material, it is possible to adjust the temperature range in which the rise of the battery temperature can be suppressed.

Moreover, the hydroxyl group or carbonyl group produced | generated from an organic material reacts with a sulfide solid electrolyte material. Also, for example, when the sulfide solid electrolyte material has an anion structure of ortho composition (for example, PS ₄ ^3- structure), it is preferable that the hydroxyl group or the carbonyl group react with the anion structure of ortho composition.

  The organic material is contained in the positive electrode layer, the solid electrolyte layer or the negative electrode layer. The organic material is not particularly limited as long as it is contained in at least one of the positive electrode active material layer, the solid electrolyte layer, and the negative electrode layer. Among them, it is preferable that the sulfide solid electrolyte material and the organic material be disposed in contact with each other. For example, at the time of a short circuit, the hydroxyl group or carbonyl group generated from the organic material can be easily reacted with the sulfide solid electrolyte material.

The organic material is preferably contained, for example, in the solid electrolyte layer. When the solid electrolyte layer contains an organic material, the content of the organic material is, for example, preferably 5% by weight or more, more preferably 10% by weight or more, and 20% by weight or more. Is more preferred. The content of the organic material is, for example, preferably 50% by weight or less, more preferably 40% by weight or less, and still more preferably 30% by weight or less. If the content of the organic material is small, it may be difficult to sufficiently suppress the rise in the temperature rise of the battery. If the content of the organic material is large, the content of the sulfide solid electrolyte material is relatively large. This is because the battery performance may decrease during normal use because the amount is reduced.
When the organic material is contained in the solid electrolyte layer, for example, it is preferable that the organic material be uniformly mixed in the solid electrolyte layer. This is because the sulfide solid electrolyte material and the organic material can be easily reacted at a temperature of 80 ° C. or more, and the resistance of the solid electrolyte layer can be easily increased.

  On the other hand, when the positive electrode layer or the negative electrode layer contains an organic material, the content of the organic material is, for example, preferably 5% by weight or more, more preferably 10% by weight or more, and 20% by weight It is more preferable that it is more than. The content of the organic material is, for example, preferably 40% by weight or less, more preferably 30% by weight or less, and still more preferably 25% by weight or less. If the content of the organic material is small, it may be difficult to sufficiently suppress the rise in the rising temperature of the battery. If the content of the organic material is large, the positive electrode active material or the negative electrode active material is relatively Since the content of H decreases, the battery performance during normal use may decrease.

  When the organic material is contained in the positive electrode layer or the negative electrode layer, the organic material may be uniformly mixed in the positive electrode layer or the negative electrode layer, or may be provided so as to be distributed more on the solid electrolyte layer side. . For example, when a sulfide solid electrolyte material is contained in the positive electrode layer or in the negative electrode layer, hydroxyl generated from the organic material is obtained by uniformly mixing the organic material in the positive electrode layer or in the negative electrode layer. This is because the group or the carbonyl group can be easily reacted with the sulfide solid electrolyte material. On the other hand, when the organic material is provided so as to be distributed more on the solid electrolyte layer side of the positive electrode layer or the negative electrode layer, the hydroxyl group generated from the organic material at the interface of the solid electrolyte layer and the positive electrode layer or the negative electrode layer Or, it is because the carbonyl group and the sulfide solid electrolyte material can be easily reacted.

2. Solid Electrolyte Layer The solid electrolyte layer in the present invention is formed between the positive electrode layer and the negative electrode layer, and contains a sulfide solid electrolyte material. The solid electrolyte layer preferably contains the above-described organic material.

As the sulfide solid electrolyte material, for example, one having Li ion conductivity is used. As the sulfide solid electrolyte material, for _{example, LiI-Li 2 S-SiS} 2, LiI-Li 2 S-P 2 O 5, LiI-Li 3 PO 4 -P 2 S 5, Li 2 S-P 2 S _{5, Li 3 PS 4, Li} 2 S-P 2 S 5, Li 2 S-P 2 S 5 -LiI, Li 2 S-P 2 S 5 -Li 2 O, Li 2 S-P 2 S 5 -Li _{2 O-LiI, 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 S-B 2 S 3, Li 2 S-P 2 S 5 -Z m S n ( however, m, n is a positive number. Z is, Ge, Zn, one of _{Ga.), Li 2 S-} GeS 2 _{Li 2 S-SiS 2 -Li 3} PO 4, Li 2 S-SiS 2 -Li x MO y ( provided that, x, y is a positive number .M is, P, Si, Ge, B , Al, Ga, In Or the like). Note that the description of “Li ₂ S—P ₂ S ₅ ” means a sulfide solid electrolyte material formed using a raw material composition containing Li ₂ S and P ₂ S _5, and the same applies to other descriptions. is there. In particular, the sulfide solid electrolyte material is preferably a material having Li ₂ S-P ₂ S ₅ as a main component. Further, the sulfide solid electrolyte material preferably contains halogen (F, Cl, Br, I). The sulfide solid electrolyte material is preferably mainly composed of an anion structure of ortho composition ((PS ₄ ^3- structure). As a sulfide solid electrolyte material having an anion structure of ortho composition, for example, li ₃ PS _{4 and, xLiI · (100-x)} (0.75Li 2 S · 0.25P 2 S 5) (x is 0 <x <30) include those of the PS ₄ skeleton such.

When the sulfide solid electrolyte material is a Li ₂ S-P ₂ S ₅ system, the ratio of Li ₂ S and P ₂ S ₅ is, in molar ratio, Li ₂ S: P ₂ S ₅ = 50: 50 It is preferable to be in the range of 100: 0, and in particular, it is preferable that Li ₂ S: P ₂ S ₅ = 70: 30 to 80:20.

The sulfide solid electrolyte material may be a sulfide glass, a crystallized sulfide glass, or a crystalline material obtained by a solid phase method. The sulfide glass can be obtained, for example, by subjecting the raw material composition to mechanical milling (ball mill etc.). The crystallized sulfide glass can be obtained, for example, by heat-treating the sulfide glass at a temperature higher than the crystallization temperature. In addition, the ion conductivity (for example, Li ion conductivity) at a normal temperature (25 ° C.) of the sulfide solid electrolyte material is, for example, preferably 1 × 10 ⁻⁵ S / cm or more, and 1 × 10 ⁻⁴ S It is more preferable that it is / cm or more. The ionic conductivity can be measured by an alternating current impedance method.

Examples of the shape of the sulfide solid electrolyte material in the present invention include particle shapes such as spherical and elliptical shapes, and thin film shapes. When the sulfide solid electrolyte material is in the form of particles, the average particle diameter (D ₅₀ ) is not particularly limited, but is preferably 40 μm or less, more preferably 20 μm or less, and 10 μm or less It is further preferred that It is because it becomes easy to aim at the filling rate improvement in a positive electrode layer. On the other hand, the average particle diameter is preferably 0.01 μm or more, and more preferably 0.1 μm or more. In addition, an average particle diameter can be determined with a particle size distribution analyzer, for example.

  The content of the sulfide solid electrolyte material in the solid electrolyte layer is, for example, preferably in the range of 10% by weight to 100% by weight, and more preferably in the range of 50% by weight to 100% by weight.

  The solid electrolyte layer formed by this step may be formed of a fluorine-containing binder such as polyvinylidene fluoride (PVdF) or polytetrafluoroethylene (PTFE), acrylate butadiene rubber (ABR), if necessary, in addition to the above-mentioned materials. Etc. may be contained. The thickness of the solid electrolyte layer is, for example, preferably in the range of 0.1 μm to 1000 μm, and more preferably in the range of 0.1 μm to 300 μm.

3. Positive Electrode Layer The positive electrode layer in the present invention is a layer containing at least a positive electrode active material, and may contain at least one of a solid electrolyte material, a conductive material, and a binder as needed. In addition, the positive electrode layer may contain an organic material.

The kind of positive electrode active material is suitably selected according to the kind of all the solid batteries, for example, an oxide active material, a sulfide active material, etc. are mentioned. As the oxide active material, for example, a rock salt layered active material such as LiCoO ₂ , LiMnO ₂ , LiNiO ₂ , LiVO ₂ , LiNi _1/3 Co _1/3 Mn _1/3 O ₂ , LiMn ₂ O ₄ , LiNi _{0. 5} Spinel type active materials such as Mn _1.5 O ₄ , olivine type active materials such as LiFePO ₄ and LiMnPO ₄ , Si-containing active materials such as Li ₂ FeSiO ₄ and Li ₂ MnSiO _{4, and the} like. As the oxide active material other than the above, for example, _Li 4 _Ti 5 _{O 12} is used.

The surface of the positive electrode active material may be coated with a coat layer. This is because the reaction between the positive electrode active material and the sulfide solid electrolyte material can be suppressed. As the material of the coating layer, for _example, a _{LiNbO 3, Li 3 PO 4,} Li ion conductive oxide such as LiPON. The average thickness of the coating layer is, for example, preferably in the range of 1 nm to 20 nm, and more preferably in the range of 1 nm to 10 nm.

Examples of the shape of the positive electrode active material include particles and thin films. When the positive electrode active material is in the form of particles, its average particle diameter (D ₅₀ ) is, for example, preferably in the range of 1 nm to 100 μm, and more preferably in the range of 10 nm to 30 μm. When the average particle size of the positive electrode active material is too small, the handling property may be deteriorated. On the other hand, when the average particle size is too large, it may be difficult to obtain a flat positive electrode layer. It is.

  Although content of the positive electrode active material in a positive electrode layer is not specifically limited, For example, it is preferable to exist in the range of 40 weight%-99 weight%.

  The positive electrode layer preferably contains a sulfide solid electrolyte material in addition to the positive electrode active material. About the specific example of a sulfide solid electrolyte material, since it is the same as that of the sulfide solid electrolyte material mentioned above, the description here is abbreviate | omitted.

  The content of the sulfide solid electrolyte material in the positive electrode layer used in the present invention is, for example, preferably in the range of 1 wt% to 90 wt%, and in the range of 10 wt% to 80 wt%. More preferable.

  The positive electrode layer in the present invention may further contain at least one of a conductive material and a binder in addition to the above-described positive electrode active material and solid electrolyte material. Examples of the conductive material include acetylene black, ketjen black, carbon nanotubes, carbon fibers (VGCF) and the like. Examples of the binder include fluorine-containing binders such as polyvinylidene fluoride (PVdF) and polytetrafluoroethylene (PTFE), styrene butadiene rubber (SBR), butadiene rubber (BR) and the like. The thickness of the positive electrode layer is different depending on the configuration of the desired all solid battery, but is preferably, for example, in the range of 0.1 μm to 1000 μm.

4. Negative Electrode Layer The negative electrode layer in the present invention is a layer containing at least a negative electrode active material, and may contain at least one of a solid electrolyte material, a conductive material, and a binder, as required.

Examples of the negative electrode active material include a metal active material, a carbon active material, and an oxide active material. Examples of the metal active material include In, Al, Si and Sn. On the other hand, examples of the carbon active material include meso carbon micro beads (MCMB), highly oriented graphite (HOPG), hard carbon, soft carbon and the like. As oxide active material may include, for example _{Nb 2 O 5, Li 4 Ti} 5 O 12, SiO and the like.

  The negative electrode layer preferably contains a sulfide solid electrolyte material in addition to the negative electrode active material. The second sulfide solid electrolyte material is the same as the contents described above.

  The conductive material and the binder used in the negative electrode layer are the same as in the case of the positive electrode layer described above. Moreover, it is preferable that the thickness of a negative electrode layer exists in the range of 0.1 micrometer-1000 micrometers, for example.

5. Other Configurations The all-solid-state battery obtained by the present invention at least has a positive electrode layer, a negative electrode layer, and a solid electrolyte layer. Furthermore, usually, it has a positive electrode current collector for collecting current of the positive electrode active material, and a negative electrode current collector for collecting current of the negative electrode active material. Examples of the material of the positive electrode current collector include SUS, aluminum, nickel, iron, titanium, carbon and the like. On the other hand, as a material of the negative electrode current collector, for example, SUS, copper, nickel, carbon and the like can be mentioned. The thickness, shape, and the like of the positive electrode current collector and the negative electrode current collector are preferably selected appropriately in accordance with the application and the like of the all-solid battery. Further, as the battery case used in the present invention, a battery case used for a general all-solid-state battery can be used, and examples thereof include a battery case made of SUS and the like. In the all-solid-state battery obtained by the present invention, the power generation element may be formed inside the insulating ring, or may be sealed by an outer package. As an exterior body, what is used for a general battery can be used, for example, an aluminum laminate film etc. can be mentioned. The all-solid-state battery may be a single-layer battery, or may be a stacked battery in which a plurality of single-layer batteries are stacked.

6. All-Solid-State Battery The all-solid-state battery (all-solid lithium battery) obtained by the present invention may be a primary battery or a secondary battery, but among them, a secondary battery is preferable. This is because it can be repeatedly charged and discharged, and is useful, for example, as a vehicle-mounted battery. When the all-solid-state battery obtained by the present invention is used as a vehicle-mounted battery, target vehicles include an electric vehicle equipped with a battery and not equipped with an engine, and a hybrid vehicle equipped with both a battery and an engine. Examples of the shape of the all-solid-state battery obtained by the present invention include coin-type, laminate-type, cylindrical and square-type and the like.

  The present invention is not limited to the above embodiment. The above embodiment is an exemplification, and it has substantially the same configuration as the technical idea described in the claims of the present invention, and any one having the same function and effect can be used. It is included in the technical scope of the invention.

  Hereinafter, the present invention will be more specifically described by way of examples.

[Experimental Example 1]
(Synthesis of sulfide solid electrolyte material)
Lithium sulfide (Li ₂ S), diphosphorus pentasulfide (P ₂ S ₅ ) and lithium iodide (LiI) were used as starting materials. Next, in a glove box under an Ar atmosphere (dew point -70 ° C.), Li ₂ S and P ₂ S ₅ become a molar ratio of 75Li ₂ S · 25P ₂ S ₅ (Li ₃ PS ₄ , ortho composition) As weighed. Next, LiI was weighed so that LiI would be 10 mol%. 2 g of this mixture is put into a container (45 cc, made of ZrO ₂ ) of a planetary ball mill, dehydrated heptane (water content 30 ppm or less, 4 g) is put, and further ZrO 2 balls (φ = 5 mm, 53 g) are put, container Completely sealed (Ar atmosphere). This container was attached to a planetary ball mill (P7, manufactured by Fritsch), and was subjected to 40 cycles of treatment for 1 hour and mechanical milling at rest for 15 minutes at a table rotation speed of 500 rpm. The resulting sample was then dried on a hot plate to remove heptane to obtain a sulfide solid electrolyte material. The composition of the obtained sulfide solid electrolyte material was 10 LiI · 90 (0.75 Li ₂ S · 0.25 P ₂ S ₅ ).

(Pulverization and crystallization of sulfide solid electrolyte material)
The synthesized sulfide solid electrolyte material was micronized and crystallized by the following method to obtain a sulfide solid electrolyte material having an average particle diameter of 1.7 μm.

The total weight of the sulfide solid electrolyte material, dehydrated heptane (manufactured by Kanto Chemical Co., Ltd.) and dibutyl ether is 10 g, and the ratio of the weight of the sulfide solid electrolyte material to the total weight is 10% by weight Prepared. The sulfide solid electrolyte material, dehydrated heptane and dibutyl ether, and 40 g of ZrO ₂ balls (φ 0.6 mm) were charged into a 45 ml ZrO ₂ pot, and the pot was completely sealed (Ar atmosphere). The pot was attached to a planetary ball mill (P7, manufactured by Fritsch), and wet mechanical milling was performed for 20 hours at a revolution speed of 150 rpm for pulverizing the sulfide solid electrolyte material into fine particles.

  By placing 1 g of the finely divided sulfide solid electrolyte material on the aluminum petri dish and holding it on a hot plate heated to 180 ° C. for 2 hours, the particulate sulfide can be obtained. The solid electrolyte material was crystallized.

[Experimental Example 2]
25 g of the sulfide solid electrolyte material obtained in Experimental Example 1 and 25 g of ethanol (C ₂ H ₅ OH) were weighed and left in the same container in a state of being sufficiently mixed. One week later, ethanol was evaporated to collect a powder of sulfide solid electrolyte material (SE powder).

[Experimental Example 3]
The same as in Experimental Example 2 except that acetone was used instead of ethanol.

[Evaluation]
(Li ion conductivity measurement)
The following evaluation cell was produced.
A predetermined amount of the obtained sulfide solid electrolyte material was weighed, and molded at 4.3 tons in an insulated container having a cross-sectional area of 1 cm ² to form pellets with a thickness of 0.5 mm. A metal rod was brought into contact with the top and bottom of the pellet, and fixed at a predetermined pressure so that the top and bottom would not be short-circuited, to obtain an evaluation cell.
The prepared evaluation cell was adjusted to 25 ° C., and then the Li ion conductivity was measured by an alternating current impedance method. The measurement was carried out under the conditions of an applied voltage of 5 mV and a measurement frequency range of 0.01 MHz to 1 MHz. The resistance value of 100 kHz was read, corrected by the thickness, and converted to lithium ion conductivity.
The results are shown in Table 1.

(Raman spectroscopy measurement)
The resulting sulfide solid electrolyte material was measured by Raman spectroscopy, but PS ₄ structure peaks was confirmed that in Examples 1 main skeleton, PS ₄ structure peaks in Examples 2 and 3 was not confirmed .

  As shown in Table 1, it was confirmed that the resistance of the sulfide solid electrolyte material significantly increases and the Li ion conductivity decreases by contacting with ethanol and acetone.

1 ... positive electrode layer 2 ... negative electrode layer 3 ... solid electrolyte layer 4 ... positive electrode current collector 5 ... negative electrode current collector 10 ... all solid battery

Claims (1)

An all solid battery comprising a positive electrode layer containing a positive electrode active material, a negative electrode layer containing a negative electrode active material, and a solid electrolyte layer formed between the positive electrode layer and the negative electrode layer and containing a sulfide solid electrolyte material And
The positive electrode layer, the solid electrolyte layer, or the negative electrode layer contains an organic material,
The organic material is, at 80 ° C. or higher, Ri materials der to generate a hydroxyl group or a carbonyl group,
The organic material that generates the hydroxyl group is at least one selected from xylitol, mannitol, erythritol, and galacitol,
The organic material to produce the carbonyl group, calcium acetate, ethylene - vinyl acetate copolymer resin, glucose, oxalic acid dihydrate, all-solid-state cell according to at least one Der wherein Rukoto selected from malonic acid .

Images