KR20140073400A - Solid battery - Google Patents

Abstract

The present invention provides a solid battery comprising a cathode, an anode, and a solid electrolyte layer disposed between the cathode and the anode. At least the cathode of the cathode and the anode, and the solid electrolyte layer include a sulfide-based solid electrolyte. The sulfide-based solid electrolyte has amorphous forms and crystal forms. The ratio of the amorphous forms (A) is higher than the ratio of the crystal forms (A′) in the sulfide-based solid electrolyte included in at least the cathode of the cathode and the anode. The ratio of the amorphous forms (B) is higher than the ratio of the crystal forms (B′) in the sulfide-based solid electrolyte included in the solid electrolyte layer.

Description

Solid battery {Solid battery}

≪ / RTI >

A solid-state battery using a solid electrolyte as a lithium ion secondary battery is known. The solid-state battery includes an electrode (positive electrode and negative electrode) formed on both surfaces of a solid electrolyte layer including a solid electrolyte and a solid electrolyte layer, and a current collector joined to each electrode.

In solid-state batteries, solid electrolytes are generally mixed with each electrode. As a solid electrolyte, a sulfide-based solid electrolyte having excellent lithium ion conductivity has been used.

Japanese Patent Application Laid-Open No. 2008-103281 discloses a solid battery using an amorphous / crystalline sulfide solid electrolyte in the solid electrolyte layer between the anode and the cathode. Japanese Patent Laid-Open No. 2008-103282 discloses a solid-state battery using an amorphous / crystalline sulfide-based solid electrolyte in a solid electrolyte of a positive electrode and / or a negative electrode.

One aspect is to provide a solid battery having improved discharge capacity and cycle characteristics.

On one side

anode; cathode; And a solid electrolyte layer disposed between the anode and the cathode,

At least an anode and a solid electrolyte layer of the anode and the cathode include a sulfide-based solid electrolyte,

Wherein the sulfide-based solid electrolyte comprises an amorphous substance and a crystalline substance,

Wherein the ratio (A) of the amorphous substance in the sulfide-based solid electrolyte contained in at least one of the positive electrode and the negative electrode is higher than the ratio (A ') of the crystalline substance,

A solid electrolyte in which a ratio (B) of an amorphous body in a sulfide-based solid electrolyte contained in a solid electrolyte layer is lower than a ratio (B ') of a crystalline body is provided.

According to one aspect of the present invention, it is possible to provide a solid battery having improved discharge capacity and cycle characteristics by setting the crystal structure of the solid electrolyte in the positive electrode, the negative electrode, and the electrolyte layer to an appropriate range.

1 is a cross-sectional view of a solid-state battery structure according to one exemplary embodiment.
Description of the Related Art
1: solid battery 2: anode current collector
3: Adhesive layer 4: anode layer
5: solid electrolyte layer 6: cathode layer
7: anode current collector 10: anode
20: cathode

Hereinafter, the solid state battery according to the exemplary embodiments will be described in more detail.

Sulfide-based solid electrolytes generally include amorphous (amorphous) solid electrolytes which are generally treated by mechanical milling (MM) of lithium sulfide (Li ₂ S) and sulfurized phosphorus (P ₂ S ₅ ) As a glass structure crystallized by firing, there is a solid electrolyte of crystalline type (crystalline substance). The former is flexible and has a lithium ion conductivity of 10 ^-4 S / cm, whereas the latter is rigid, but has a lithium ion conductivity of 10 ^-3 S / cm, which is one digit larger than the amorphous type.

In order to improve the output characteristics of the solid-state battery, it is preferable to use a crystalline type in which the lithium ion conductivity is high and the discharge capacity of the battery can be increased. However, charging / discharging of the solid state battery involves expansion / contraction of the electrode active material, The use of a solid electrolyte causes pores at the interface between the electrode active material and the crystalline solid electrolyte, which becomes a high-resistance layer, deteriorating the charge-discharge cycle characteristics of the solid-state battery.

As a result of the inventors' earnest study, it has been found that by controlling the ratio of the amorphous structure in the solid electrolyte in the positive electrode and the negative electrode and the ratio of the amorphous structure in the solid electrolyte in the solid electrolyte layer, And the generation of pores at the interface between the solid electrolyte and the solid electrolyte can be suppressed and the deterioration of the cycle characteristics of the battery can be prevented.

By using a flexible amorphous solid electrolyte in combination with the crystalline solid electrolyte and the positive electrode and / or the negative electrode, voids can be prevented from occurring at the interface between the electrode active material and the solid electrolyte at the time of charging and discharging.

On the other hand, since the solid electrolyte layer receives only the stress accompanying the change in volume from the positive electrode and the negative electrode in the charging and discharging process, the volume change of the solid electrolyte itself hardly occurs. Therefore, it is possible to use a large amount of a crystalline solid electrolyte having a higher ionic conductivity than the amorphous solid electrolyte in the solid electrolyte layer. As described above, since a large amount of amorphous solid electrolyte is contained in the anode and / or a cathode and a crystalline solid electrolyte is contained in the solid electrolyte layer, the gap of the active material-solid electrolyte Can be prevented.

That is, the solid battery according to an embodiment includes a positive electrode; cathode; And a solid electrolyte layer disposed between the anode and the cathode, wherein at least an anode and a solid electrolyte layer of the anode and the cathode include a sulfide-based solid electrolyte, and the sulfide-based solid electrolyte includes an amorphous substance and a crystalline substance , The ratio (A) of the amorphous body in the sulfide-based solid electrolyte contained in at least one of the positive electrode and the negative electrode is higher than the ratio (A ') of the crystalline body, and the ratio of the amorphous body in the sulfide- (B) is lower than the ratio (B ') of the crystalline body.

The sulfide-based solid electrolyte is necessarily contained in the anode and may be selectively contained in the cathode. The ratio (A ') of the crystalline body in the anode means a portion occupied by the crystalline body in the total weight of the amorphous body and the crystalline body contained in the cathode. In addition, the ratio (A) of the amorphous body in the anode means the amount occupied by the amorphous body in the total weight of the amorphous body and the crystalline body contained in the anode. The same applies to the solid electrolyte layer.

In the solid electrolyte, the ratio (A) of the amorphous material in the solid electrolyte contained in at least the positive electrode and the negative electrode may be higher than the ratio (B) of the amorphous material in the solid electrolyte included in the solid electrolyte layer.

For example, when the cathode does not include the solid electrolyte, the ratio (A) of the amorphous body in the solid electrolyte of the anode is larger than the ratio (A) of the amorphous body in the solid electrolyte. In the case where the anode includes the solid electrolyte, The ratio (A) of the amorphous body in the solid electrolyte is higher than the ratio (B) of the amorphous body in the solid electrolyte in the solid electrolyte layer.

For example, a solid electrolyte layer having a positive electrode and a negative electrode, and a solid electrolyte existing between the positive electrode and the negative electrode, wherein the positive electrode and the negative electrode each include a solid electrolyte, and the solid electrolyte includes amorphous and crystalline (A) of the amorphous body in the solid electrolyte of the positive electrode when the negative electrode does not include a solid electrolyte and a ratio (A) of the amorphous body in the solid electrolyte of the positive electrode to the solid The ratio (A) of the amorphous body in the electrolyte to the ratio (B) of the amorphous body in the solid electrolyte of the solid electrolyte layer can be set in the following relationship.

0 &lt; B < A < 1

For example, in the solid-state battery, the ratio (A) of the amorphous body in the solid electrolyte contained in at least the positive electrode of the positive electrode and the negative electrode and the ratio (B) of the amorphous body in the solid electrolyte included in the solid electrolyte layer are as follows Can be set.

0.1? B? A? 0.9

For example, in the solid-state battery, the ratio (A) of the amorphous body in the solid electrolyte contained in at least the positive electrode of the positive electrode and the negative electrode and the ratio (B) of the amorphous body in the solid electrolyte of the solid electrolyte layer are Can be set in relation.

0.1 < B < 0.5 &lt; A &

If the ratio (B) of the amorphous substance in the solid electrolyte layer of the solid electrolyte layer is less than 0.1, the flexibility of the solid electrolyte is not sufficient. If the ratio is more than 0.5, the proportion of the crystalline substance is low, Can be lowered. When the ratio (A) of the amorphous body in the solid electrolyte in the positive electrode and the negative electrode is 0.5 or less, the proportion of the amorphous material decreases and the electrode active material expands and shrinks with the charge and discharge of the battery, If the ratio exceeds 0.9, the ratio of the crystalline body may be lowered and the discharge capacity may be lowered.

For example, the ratio (A) of the amorphous body in the solid electrolyte contained in the positive electrode or in the positive electrode and the negative electrode in the solid battery may be 0.5 < A < 0.9. For example, in the solid electrolyte, the ratio (A) of the amorphous body to the positive electrode or the solid electrolyte contained in the positive electrode and the negative electrode may be 0.7 <A <0.9. For example, the ratio (A) of the amorphous body in the solid electrolyte contained in the positive electrode or the positive electrode and the negative electrode in the solid electrolyte may be 0.75 < A < 0.85.

For example, in the solid electrolyte, the ratio (B) of the amorphous body in the solid electrolyte contained in the solid electrolyte layer may be 0.1 < B < 0.5. For example, the ratio (B) of the amorphous body in the solid electrolyte contained in the solid electrolyte layer in the solid-state battery may be 0.1 < B < 0.3. For example, in the solid electrolyte, the ratio (B) of the amorphous body in the solid electrolyte contained in the solid electrolyte layer may be 0.15 < B < 0.25.

In the solid-state battery, the solid electrolyte may be formed from a sulfide-based solid electrolyte. For example, the sulfide-based solid electrolyte may be formed from a mixture of lithium sulfide and dihydrogen sulfide.

For example, in the solid-state battery, the ratio (A1) of lithium sulfide in the solid electrolyte contained in the positive electrode may be higher than the ratio (B1) of lithium sulfide in the solid electrolyte contained in each of the negative electrode and the solid electrolyte layer. The ratio (A1) of lithium sulfide in the positive electrode means a content of lithium sulfide in the total moles of lithium sulfide and pentoxide contained in the positive electrode. The same applies to the negative electrode and the solid electrolyte layer.

For example, in the solid-state battery, the ratio (A1) of lithium sulfide in the solid electrolyte contained in the positive electrode and the ratio (B1) of lithium sulfide in the solid electrolyte contained in each of the negative electrode and the solid electrolyte layer can satisfy the following relationship .

0.6? B1 <A1? 0.85

For example, in the solid-state battery, the ratio (A1) of lithium sulfide in the solid electrolyte contained in the anode may be 0.70? A1? 0.85. For example, in the solid battery, the ratio (A1) of lithium sulfide in the solid electrolyte contained in the anode may be 0.75? A1? 0.85. For example, in the solid electrolyte contained in the anode, lithium sulfide and hydrogen peroxide can be mixed in a molar ratio of 8.5: 1.5 to 7: 3.

For example, the ratio (B1) of lithium sulfide contained in each of the anode and the solid electrolyte layers in the solid-state battery may be 0.60? B <0.75. For example, the ratio (B1) of lithium sulfide contained in each of the negative electrode and the solid electrolyte layer in the solid-state battery may be 0.65? B <0.75. For example, lithium sulfide and hydrogen peroxide can be mixed in a molar ratio of 6: 4 to 7.5: 2.5 in the solid electrolyte contained in each of the negative electrode and the solid electrolyte layer.

Hereinafter, the solid-state battery will be described in more detail with reference to the drawings.

<1. Configuration of solid battery>

First, the configuration of the solid-state battery 1 according to one embodiment will be described with reference to Fig. The solid-state battery 1 includes a positive electrode collector 2, an adhesive layer 3, a positive electrode layer 4, a solid electrolyte layer 5, a negative electrode layer 6, and a negative electrode collector 7 . The positive electrode 10 of the solid electrolyte battery 1 is constituted by the adhesive layer 3 and the positive electrode layer 4 and the negative electrode layer 6 constitutes the negative electrode 20 of the solid electrolyte battery 1. Further, the solid-state battery 1 may not include the adhesive layer 3.

The anode current collector 2 may be any conductive material, and may be composed of, for example, aluminum, stainless steel, and nickel-plated steel.

The adhesive layer 3 is for binding the positive electrode collector 2 and the positive electrode layer 4 together. The adhesive layer 3 may include an adhesive layer conductive material, a first binder, and a second binder. The adhesive layer conductive material is not particularly limited as long as it is a carbon black such as Ketjen black or acetylene black, graphite, natural graphite, artificial graphite and the like, as long as it enhances the conductivity of the adhesive layer 3, Can be mixed and used.

The first binder is, for example, a non-polar resin having no polar functional group. Therefore, the first binder is inert to a highly reactive solid electrolyte, particularly, a sulfide-based solid electrolyte. The sulfide-based solid electrolyte is known to be active for functional groups having polar structures such as acids, alcohols, amines, and ethers. The first binder is for binding to the anode layer 3. If the anode layer 4 contains the first binder or the like, the first binder in the adhesive layer 3 is the adhesive layer 3 And the anode layer 4 and the first binder in the anode layer 4 can be strongly bonded to the anode layer 4 by interdiffusion with the first binder in the anode layer 4. [ Therefore, the positive electrode layer 4 may contain the first binder.

Examples of the first binder include styrene-based thermoplastic urethanes such as SBS (styrene-butadiene block copolymer), SEBS (styrene-ethylene-butadiene-styrene block copolymer), and styrene-styrene butadiene- (Styrene-butadiene rubber), BR (butadiene rubber), NR (natural rubber), IR (isoprene rubber), EPDM (ethylene-propylene-diene terpolymer), and partial hydrides thereof Complete hydrides can be exemplified. Examples of the binder resin include, but are not limited to, polystyrene, polyolefin, olefinic thermoplastic elastomer, polycycloolefin, silicone resin, and the like, and any resin that can be used as a binder in the art as a non- Do.

The second binder is a binder excellent in binding property to the positive electrode collector 2 than the first binder. For example, a binder film obtained by applying a binder solution to the positive electrode collector 2 and drying the same, is used as a binder from the positive electrode current collector 2 The strength required for peeling can be judged by measuring with a commercially available peeling tester. The second binder is, for example, a polar functional group-containing resin having a polar functional group, and can strongly bind to the positive electrode collector 2 through a hydrogen bond or the like. However, since the second binder often has high reactivity with respect to the sulfide-based solid electrolyte, it is not included in the anode layer 4.

Examples of the second binder include NBR (nitrile rubber), CR (chloroprene rubber), partial hydrides thereof, or complete hydrides, copolymers of polyacrylic esters, PVDF (polyvinylidene fluoride) , VDF-HFP (vinylidene fluoride-hexafluoropropylene copolymer), and carboxylic acid modified products thereof, CM (chlorinated polyethylene), polymethacrylic acid ester, polyvinyl alcohol, ethylene-vinyl alcohol copolymer , Polyimide, polyamide, polyamideimide, and the like. The first binder may be a polymer obtained by copolymerizing a monomer having carboxylic acid, sulfonic acid, phosphoric acid, or the like, but is not limited thereto. Any polar resin that can be used as a binder in the related art It is possible.

The content of the adhesive layer conductive material is not particularly limited as long as the content ratio of the adhesive layer conductive material, the first binder and the second binder is, for example, The content of the first binder may be 3 to 30 wt% based on the total weight of the adhesive layer 3 and the content of the second binder may be 2 to 20 wt% based on the total weight of the adhesive layer 3.

The anode layer 4 may include a sulfide-based solid electrolyte, a cathode active material, and a cathode layer conductive material. The anode layer conductive material may be a material such as an adhesive layer conductive material.

The sulfide-based solid electrolyte contains at least lithium sulfide as a first component and is synthesized from at least one compound selected from the group consisting of silicon sulfide, phosphorus sulfide and boron sulfide as a second component, and particularly, Li ₂ SP ₂ S ₅ Lt; / RTI &gt; The sulfide-based solid electrolyte may contain a sulfide such as SiS ₂ , GeS ₂ or B ₂ S _{3 in} addition to Li ₂ SP ₂ S ₅ , which is known to have higher lithium ion conductivity than other inorganic compounds. The solid electrolyte may further contain an inorganic solid electrolyte to which Li ₃ PO ₄ , a halogen, a halogen compound or the like is added to an inorganic solid electrolyte consisting of a combination of Li ₂ SP ₂ S ₅ , SiS ₂ , GeS ₂ , B ₂ S ₃ , An electrolyte may be used.

The sulfide-based solid electrolyte may be produced from lithium sulfide and / or sulfur sulfide (P ₂ S ₅ ) or lithium sulfide with a single phosphorus or a single sulfur, or lithium sulfide, sulfur phosphorus, group phosphorus and / or sulfur .

Lithium sulfide for producing the sulfide-based solid electrolyte can be industrially available, but may be high purity.

For example, lithium sulfide has a total content of 0.15% by mass or less, more preferably 0.1% by mass or less, and the content of lithium N-methylaminobutyrate in the lithium salt of the sulfur oxide is 0.15% by mass or less, May be 0.1 mass% or less.

When the total content of the sulfur oxide in the lithium salt is 0.15 mass% or less, the solid electrolyte obtained by the dissolution quenching method or the mechanical milling method may be a glassy solid electrolyte (complete amorphous body). That is, when the total content of the sulfur oxide in the lithium salt exceeds 0.15 mass%, there is a possibility that a crystalline product having a low ionic conductivity is obtained. In addition, such a crystalline product is not changed by heat treatment, and thus a solid electrolyte having high ion conductivity may not be obtained.

When the content of lithium N-methylaminobutylate is 0.15 mass% or less, the heat capacity of the lithium N-methylaminobutylate does not deteriorate the cycle performance of the lithium battery.

Therefore, by using the lithium sulfide in which the impurities are reduced as described above, a solid electrolyte having high ion conductivity can be obtained.

The lithium sulfide (Li ₂ S) used for the production of the high ionic conductivity solid electrolyte is not particularly limited as long as it can reduce the impurities. For example, lithium hydroxide and hydrogen sulfide are reacted in an aprotic organic solvent at 0 to 150 ° C to produce lithium hydrosulfide (LiSH), and then the reaction solution is heated to 150 to 200 ° C to remove hydrogen sulfide (H ₂ S) A method of directly producing lithium sulfide by reacting lithium hydroxide and hydrogen sulfide at 150 to 200 ° C in an aprotic organic solvent, a method of reacting lithium hydroxide and a sulfur source in a gaseous state at a temperature of 130 to 445 ° C, and the like Can be used.

The method of purifying lithium sulfide is not particularly limited. For example, lithium sulfide is washed with an organic solvent at a temperature of 100 캜 or higher. The organic solvent used for washing is preferably an aprotic polar solvent, and further, the aprotic organic solvent used for preparing lithium sulfide and the aprotic polar organic solvent used for cleaning may be the same. Examples of the aprotic polar organic solvent used for washing include non-fluorinated polar organic compounds such as an amide compound, a lactam compound, a urea compound, an organic sulfur compound, and a cyclic organic phosphorus compound. It can be suitably used as a single solvent or a mixed solvent. For example, N-methyl-2-pyrrolidone (NMP) may be selected.

The amount of the organic solvent used for washing is not particularly limited, and the number of times of washing is not particularly limited, but may be two or more times. The cleaning can be carried out under an inert gas such as nitrogen or argon.

The washed lithium sulfide is dried at a temperature equal to or higher than the boiling point of the organic solvent used for washing at atmospheric pressure or reduced pressure for 5 minutes or more, for example, for about 2 to 3 hours or more under an inert gas atmosphere such as nitrogen, Can be manufactured.

P ₂ S ₅ can be used without any particular limitation as far as it is industrially produced and sold. However, instead of P ₂ S ₅ , it is also possible to use (P) and a unitary sulfur (S) which are groups of a corresponding molar ratio. The group phosphorus (P) and the group sulfur (S) can be used without particular limitation, as long as they are industrially produced and sold.

The mixing molar ratio of the lithium sulfide to the sulfur and / or the group sulfur and / or the sulfur and / or the sulfur may be, for example, 50:50 to 80:20, for example, 60:40 to 80:20. For example, a molar ratio of Li ₂ S: P ₂ S ₅ = 70: 30 to 80:20.

The sulfide-based solid electrolyte can be obtained by dissolving and mixing Li ₂ S and P ₂ S ₅ in a predetermined ratio by heating to a dissolution temperature or higher, holding the mixture for a predetermined time, and quenching it (dissolution quenching method) . Further, Li ₂ SP ₂ S ₅ can be obtained by treating by mechanical milling.

The ratio A1 of the lithium sulfide in the solid electrolyte in the anode may be set so that 0.6? B1 < A1? 0.85 with respect to the ratio (B1) of the lithium sulfide in the solid electrolyte and the solid electrolyte in each of the above- have. The mixing ratio of Li ₂ SP ₂ S ₅ is 70/30? (Lithium sulfide / sulfur pentafluoride)? 85/15 in the anode and is 60/40? (Lithium sulfide / lithium sulfide) in each of the solid electrolyte layer and the cathode, And the molar ratio (D) of lithium sulfide and lithium sulfide in each of the solid electrolyte layer and the cathode in the positive electrode is in the range of 60/40? D < C &lt; / = 85/15.

In addition to the sulfide-based solid electrolyte as the solid electrolyte, a lithium ion conductor composed of an inorganic compound may be additionally contained as a solid electrolyte. Examples of such a lithium ion conductor, for example, Li3N, LISICON, LIPON (Li 3 + y PO 4-x N x), Thio-LISICON (Li 3.25 Ge 0.25 P 0.75 S 4), Li 2 O-Al 2 O 3 _- TiO _{2 -} P ₂ O ₅ (LATP).

The solid electrolyte may have a structure such as amorphous, glassy, crystalline (crystallized glass), or the like. When the solid electrolyte is a sulfide-based solid electrolyte made of Li ₂ SP ₂ S ₅ , the lithium ion conductivity of the amorphous material is 10 ^-4 S / cm. On the other hand, the lithium ion conductivity of the crystalline material is 10 ^-3 S / cm.

The sulfide-based solid electrolyte in each of the positive electrode, the negative electrode and the electrolyte layer may be composed of a mixture of an amorphous substance and a crystalline substance. The amorphous body can be produced by mixing the first component and the second component of the above-described sulfide and treating the resultant by a mechanical milling method. The crystalline body can be produced by calcining the amorphous body.

More specifically, the method for producing the amorphous sulphide-based solid electrolyte may be, for example, a dissolution quenching method or a mechanical milling method (MM method).

In the dissolution quenching method, Li ₂ S is mixed with P ₂ S ₅ in a predetermined amount of pestle and pellet is put into a carbon coated quartz tube and sealed in a vacuum. Subsequently, after the reaction is carried out at a constant reaction temperature, it is poured into ice water and quenched, whereby a sulfide-based amorphous substance can be obtained.

The reaction temperature during the reaction may be, for example, 400 ° C to 1000 ° C, for example, 800 ° C to 900 ° C. The reaction time may be, for example, 0.1 hour to 12 hours, for example, 1 to 12 hours. The quenching temperature of the reactant may be, for example, 10 ° C or less, for example, 0 ° C or less, and the cooling rate may be 1 to 10000 K / sec, for example, 1 to 1000 K / sec.

According to the mechanical milling method, a sulfide-based amorphous material can be obtained by mixing Li ₂ S with P ₂ S ₅ in a predetermined amount of a mortar and subjecting the mixture to mechanical milling for a certain period of time.

In the mechanical milling method using the raw material, the reaction can be carried out at room temperature. According to the mechanical milling method, since the amorphous solid electrolyte can be produced at room temperature, the amorphous solid electrolyte having the injected composition can be obtained without pyrolysis of the raw material. In mechanical milling, the amorphous solid electrolyte can be pulverized simultaneously with the production of the amorphous solid electrolyte.

The mechanical milling method can use various types of milling methods, but a planetary ball mill can be used. In the planetary ball mill, the spigot phase revolves while the pot rotates and rotates, so that a very high impact energy can be efficiently generated.

The rotation speed and the rotation time of the mechanical milling method are not particularly limited. However, as the rotation speed is high, the production rate of the amorphous solid electrolyte is accelerated, and the longer the rotation time, the higher the conversion ratio of the amorphous solid electrolyte raw material can be.

For example, when a planetary ball mill is used, the rotation speed can be set to several tens to several hundreds rpm and can be applied for 0.1 to 100 hours.

The amorphous sulphide-based solid electrolyte which can be produced by the above-described method is burned at a high temperature to obtain a crystalline sulphide-based solid electrolyte. The combustion temperature may be, for example, 190 ° C to 340 ° C, for example, 195 ° C to 335 ° C, for example, 200 ° C to 330 ° C. If the combustion temperature is lower than 190 ° C, it may be difficult to obtain a crystalline material having high ion conductivity. If the combustion temperature is higher than 340 ° C, a crystalline material having a low ion conductivity may be produced.

For example, the heat treatment time may be 0.1 to 240 hours, particularly 0.2 to 230 hours in the case of the heat treatment temperature of 190 占 폚 to 340 占 폚. For example, if the heat treatment time is less than 0.1 hour, it may be difficult to obtain a high ion conductive crystalline body, and if it exceeds 240 hours, a crystalline body having low ion conductivity may be produced.

By using a flexible amorphous solid electrolyte in combination with the crystalline solid electrolyte and the positive electrode and / or the negative electrode, voids can be prevented from being generated at the interface between the electrode active material and the solid electrolyte at the time of charging and discharging.

On the other hand, since the solid electrolyte layer receives only the stress accompanied by the volume change from the anode and the cathode in the charging and discharging process, the volume change of the solid electrolyte itself hardly occurs. Therefore, a crystalline solid electrolyte in which the ion conductivity is larger than that of the amorphous solid electrolyte can be used for the solid electrolyte layer.

As described above, since the amorphous solid electrolyte is contained in the anode and / or the cathode and the crystalline solid electrolyte is contained in the solid electrolyte layer, the generation of voids in the active material-solid electrolyte at the charge / .

The ratio (A) of the amorphous solid electrolyte in the anode to the amorphous solid electrolyte in the solid electrolyte and the ratio (B) of the amorphous solid electrolyte in the solid electrolyte can be set to satisfy the relationship 0.1 <B <0.5 <A <0.9.

If the proportion (B) of the amorphous body in the solid electrolyte of the solid electrolyte layer is less than 0.1, the flexibility of the solid electrolyte is not sufficient. If the ratio is more than 0.5, the proportion of the crystalline body is lowered, Can be degraded.

When the ratio (A) of the amorphous body in the solid electrolyte in the positive electrode to the negative electrode is 0.5 or less, the proportion of the amorphous material is lowered and the electrode active material expands / shrinks with the charge / discharge of the battery, And when it exceeds 0.9, the ratio of the crystalline material decreases, and the discharge capacity may be lowered.

The cathode active material is not particularly limited as long as it is a material capable of reversibly intercalating and deintercalating lithium ions, and examples thereof include lithium cobalt oxide (LCO), lithium nickel oxide, lithium nickel cobaltate, lithium nickel cobalt aluminum oxide (Hereinafter also referred to as NCA), lithium nickel cobalt manganese oxide (hereinafter also referred to as NCM), lithium manganese oxide, lithium iron phosphate, nickel sulfide, copper sulfide, sulfur, , Iron oxide, vanadium oxide, and the like. These cathode active materials may be used alone or in combination of two or more.

For example, the cathode active material is a lithium-containing metal oxide, and any of those conventionally used in the art can be used without limitation. For example, at least one of complex oxides of metal and lithium selected from cobalt, manganese, nickel, and combinations thereof may be used. Specific examples thereof include Li _a A _1-b B _b D ₂ 0.90? A? 1, and 0? B? 0.5); Li _a E _1-b B _b O _{2 -c} D _{c where} 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05; LiE (in the above formula, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05) 2-b B b O 4-c D c; Li _a Ni _{1 -bc} Co _b B _c D _? Wherein, in the formula, 0.90? A? 1, 0? B? 0.5, 0? C? 0.05, 0 <? Li _a Ni _{1- b c} Co _b B _c O _{2 -?} F _? Wherein? 0.90? A? 1, 0? B? 0.5, 0? C? 0.05, 0 <? Li _a Ni _{1- b c} Co _b B _c O _2-α F ₂ wherein 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 <α <2; Li _a Ni _1-bc Mn _b B _c D _{? Where} 0.90? A? 1, 0? B? 0.5, 0? C? 0.05, 0 <?? 2; Li _a Ni _1-bc Mn _b B _c O _2-α F _α wherein 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 <α <2; Li _a Ni _1-bc Mn _b B _c O _2-α F ₂ wherein 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 <α <2; Li _a Ni _b E _c G _d O ₂ wherein 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.9, 0 ≤ c ≤ 0.5, and 0.001 ≤ d ≤ 0.1; Li _a Ni _b Co _c Mn _d GeO ₂ wherein 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.9, 0 ≤ c ≤ 0.5, 0 ≤ d ≤ 0.5, and 0.001 ≤ e ≤ 0.1; Li _a NiG _b O ₂ (in the above formula, 0.90? A? 1, and 0.001? B? 0.1); Li _a CoG _b O ₂ (in the above formula, 0.90? A? 1, 0.001? B? 0.1); Li _a MnG _b O ₂ (in the above formula, 0.90? A? 1, 0.001? B? 0.1); Li _a Mn ₂ G _b O ₄ (in the above formula, 0.90? A? 1, 0.001? B? 0.1); QO _2; QS ₂ ; LiQS ₂ ; V ₂ O ₅ ; LiV ₂ O ₅ ; LiIO ₂ ; LiNiVO _4; Li _(3-f) J ₂ (PO ₄ ) ₃ (0? F? 2); Li _(3-f) Fe ₂ (PO ₄ ) ₃ (0? F? 2); In the formula of LiFePO ₄ may be used a compound represented by any one:

In the above formula, A is Ni, Co, Mn, or a combination thereof; B is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element or a combination thereof; D is O, F, S, P, or a combination thereof; E is Co, Mn, or a combination thereof; F is F, S, P, or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or combinations thereof; Q is Ti, Mo, Mn, or a combination thereof; I is Cr, V, Fe, Sc, Y, or a combination thereof; J is V, Cr, Mn, Co, Ni, Cu, or a combination thereof.

For example, LiCoO ₂ , LiMn _x O _2x (x = 1, 2), LiNi _1-x Mn _x O _2x (0 <x <1), LiNi _1-xy Co _x Mn _y O ₂ 0.5, 0? Y? 0.5), FePO _4, and the like.

Of course, a compound having a coating layer on the surface of the compound may be used, or a compound having a coating layer may be mixed with the compound. The coating layer may comprise an oxide, a hydroxide of the coating element, an oxyhydroxide of the coating element, an oxycarbonate of the coating element, or a coating element compound of the hydroxycarbonate of the coating element. The compound constituting these coating layers may be amorphous or crystalline. The coating layer may contain Mg, Al, Co, K, Na, Ca, Si, Ti, V, Sn, Ge, Ga, B, As, Zr or a mixture thereof. The coating layer forming step may be any coating method as long as it can coat the above compound by a method that does not adversely affect physical properties of the cathode active material (for example, spray coating, dipping, etc.) by using these elements, It will be understood by those skilled in the art that a detailed description will be omitted.

The cathode active material may be a lithium salt of a transition metal oxide having a layered salt salt type structure, among the cathode active materials exemplified above. In the present specification, the term "layered" means a thin sheet state, and "rock salt type structure" means a sodium chloride type structure having one kind of crystal structure, Quot; is < / RTI &gt; As the lithium salt of the transition metal oxide having such a layered rock salt type structure, for example, Li _{1- y z} Ni _x Co _y Al _z O ₂ (NCA) or Li _{1 -yz} Ni _x Co _y Mn _z O ₂ (NCM) (0 <x <1, 0 <y <1, 0 <z <1, x + y + z = 1).

The positive electrode layer binder may be, for example, a non-polar resin having no polar functional group. Therefore, the positive electrode layer binder may be inert to a highly reactive solid electrolyte, particularly, a sulfide-based solid electrolyte. As the anode layer binder, for example, the first binder described above may be included. Since the electrolyte of the solid electrolyte battery 1 is a sulfide-based solid electrolyte having high reactivity, the anode layer binder may be a non-polar resin.

There is a possibility that the anode layer 4 does not sufficiently adhere to the anode current collector 2 even if the cathode layer 4 is directly bonded to the cathode current collector 2. [ Therefore, the adhesive layer 3 including the first binder and the second binder can be interposed between the anode layer 4 and the cathode current collector 2. [ As a result, the first binder in the adhesive layer 3 binds strongly to the anode layer 4 and the second binder in the adhesive layer 3 binds strongly to the cathode current collector 2, The anode layer 4 can be strongly bonded. When the first binder is used as the anode layer binder, the first binder in the adhesive layer 3 is bonded to the first binder in the anode layer 4 through the interface between the adhesive layer 3 and the anode layer 4 By the mutual diffusion, the anode layer 4 and the cathode current collector 2 are strongly bonded.

The ratio of the content of the sulfide-based solid electrolyte, the positive electrode active material, the positive electrode layer conductive material, and the positive electrode layer binder in the positive electrode is not particularly limited. For example, the content of the sulfide-based solid electrolyte is 20 to 50% by weight based on the total weight of the anode layer 4, the content of the cathode active material is 45 to 75% by weight with respect to the total weight of the anode layer 4, The content of the material may be 1 to 10% by weight based on the total weight of the anode layer 4 and the content of the anode layer binder may be 0.5 to 4% by weight based on the total weight of the anode layer 4.

The electrolyte layer 5 may include a sulfide-based solid electrolyte and an electrolyte binder. The electrolyte binder is a non-polar resin having no polar functional group. Therefore, the electrolyte binder may be inert to a highly reactive solid electrolyte, particularly a sulfide-based solid electrolyte. The electrolyte binder may include, for example, a first binder. The first binder in the electrolyte layer 5 is formed by interdiffusion with the first binder in the anode layer 4 through the interface between the anode layer 4 and the electrolyte layer 5, The electrolyte layer 5 can strongly bind. The ratio of the content of the sulfide-based solid electrolyte and the electrolyte binder is not particularly limited. For example, the content of the sulfide-based solid electrolyte may be 95 to 99.9% by weight based on the total weight of the electrolyte layer 5, and the content of the electrolyte binder may be 0.5 to 5% by weight based on the total weight of the electrolyte layer 5 .

The cathode layer 6 may include a negative electrode active material, a negative electrode binder and a solid electrolyte. The negative electrode binder may include the above-described first binder. The first binder of the negative electrode layer 6 can strongly bind the negative electrode layer 6 and the electrolyte layer 5 by mutual diffusion with the first binder of the electrolyte layer 5. [

In addition, the negative electrode active material can be used as the negative electrode active material of the lithium battery in the related art. For example, at least one selected from the group consisting of a lithium metal, a metal capable of alloying with lithium, a transition metal oxide, a non-transition metal oxide, and a carbon-based material.

For example, the metal that can be alloyed with lithium is at least one element selected from the group consisting of Si, Sn, Al, Ge, Pb, Bi, Sb Si-Y alloys (Y is at least one element selected from the group consisting of alkali metals, alkaline earth metals, Group 13 elements, Group 14 elements, (Wherein Y is an alkali metal, an alkaline earth metal, a Group 13 element, a Group 14 element, a transition metal, a rare earth element, or a combination element thereof, and not a Sn element) ) And the like. The element Y may be at least one element selected from the group consisting of Mg, Ca, Sr, Ba, Ra, Sc, Y, Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Pb, Ru, Os, Hs, Rh, Ir, Pd, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, Sn, In, Ti, Ge, P, As, Sb, Se, Te, Po, or a combination thereof.

For example, the transition metal oxide may be lithium titanium oxide, vanadium oxide, lithium vanadium oxide, or the like.

For example, the non-transition metal oxide may be SnO ₂ , SiO _x (0 <x <2), or the like.

The carbon-based material may be crystalline carbon, amorphous carbon, or a mixture thereof. The crystalline carbon may be graphite such as natural graphite or artificial graphite in an amorphous, plate-like, flake, spherical or fibrous shape, and the amorphous carbon may be soft carbon or hard carbon carbon, mesophase pitch carbide, calcined coke, and the like.

In particular, graphite active materials such as artificial graphite, natural graphite, a mixture of artificial graphite and natural graphite, and natural graphite coated with artificial graphite can be exemplified as the negative electrode active material. As the negative electrode active material, tin (Sn) and silicon (Si) materials can be used instead of graphite.

The ratio of the content of the negative electrode active material, the solid electrolyte, the first binder, and the second binder is not particularly limited. For example, the content of the sulfide-based solid electrolyte is 0 to 40% by weight based on the total weight of the cathode layer 6, the content of the anode active material is 60 to 100% by weight based on the total weight of the cathode layer 6, The content of the binder may be 0.5 to 50% by mass based on the total weight of the cathode layer 6. The anode current collector 7 may be any conductor, and may be made of copper, stainless steel, nickel-plated steel, or the like, for example. In addition, known additives can be appropriately added to the respective layers described above.

In the solid-state battery, the solid electrolyte layer may have a higher lithium ion conductivity than the positive electrode and the negative electrode. The solid electrolyte layer has a higher lithium ion conductivity than the positive electrode and the negative electrode, thereby providing improved battery characteristics.

<2. Manufacturing Method of Solid Battery>

Next, an exemplary embodiment of the manufacturing method of the solid state battery 1 will be described. First, an adhesive layer coating liquid containing a first binder, a second binder, an adhesive layer conductive material, and a first solvent for dissolving the first and second binders is produced. Examples of the first solvent include amide solvents such as NMP (N-methylpyrrolidone), DMF (N, N-dimethylformamide) and N, N-dimethylacetamide, butyl acetate, Ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone; ethers such as tetrahydrofuran and diethyl ether; and alcohols such as methanol, ethanol and isopropyl alcohol. As described later, since the adhesive layer 3 does not contain a sulfide-based solid electrolyte or contains a small amount of a sulfide-based solid electrolyte expanded from the anode layer 4, a polar solvent can be used for the first solvent.

Next, the adhesive layer coating solution is coated on the cathode current collector 2 and dried to produce the adhesive layer 3. [ Further, an adhesive layer coating liquid is coated on a substrate such as a tabletop screen printing machine and dried to form an adhesive film, and the adhesive film can be pressed onto the cathode current collector 2. [

Next, a positive electrode layer coating liquid containing a sulfide-based solid electrolyte, a positive electrode active material, a positive electrode layer conductive material and a second solvent for dissolving the positive electrode layer binder is produced. The second solvent dissolves the positive electrode layer binder (first binder), but does not dissolve the second binder. Specific examples of the second solvent include non-polar solvents such as aromatic hydrocarbons such as xylene, toluene and ethylbenzene, and aliphatic hydrocarbons such as pentane, hexane and heptane. Then, the positive electrode layer coating liquid is coated on the adhesive layer 3 and dried to produce the positive electrode layer 4. As a result, the first binder in the adhesive layer 3 dissolves in the second solvent and expands into the anode layer 4, so that the adhesion between the adhesive layer 3 and the anode layer 4 can be strengthened. Thus, in an exemplary embodiment, the anode 10 is formed by coating, so that the large-area anode 10 can be easily manufactured. That is, in this embodiment, a large-capacity solid battery 1 can be easily manufactured.

In addition, since the second solvent does not dissolve the second binder, when the anode layer coating liquid is coated on the adhesive layer 3, the second binder in the adhesive layer 3 is prevented from expanding into the anode layer 4 . From this, it is possible to prevent the sulfide-based solid electrolyte in the anode layer 4 from being deteriorated by the second binder. By the above process, a positive electrode structure including the positive electrode collector 2, the adhesive layer 3, and the positive electrode layer 4 is produced.

On the other hand, a negative electrode coating liquid containing a second binder, a negative electrode active material, a sulfide-based solid electrolyte and a second solvent is produced. When the cathode layer 6 does not contain a sulfide-based solid electrolyte, a first solvent (polar solvent) may be used. Then, the negative electrode layer coating liquid is coated on the negative electrode collector 7 and dried to produce the negative electrode layer 6. [ Thus, a cathode structure is produced.

Then, an electrolyte layer coating liquid containing a sulfide-based solid electrolyte, an electrolyte binder and a second solvent is produced. Then, the electrolyte layer coating liquid is coated on a substrate such as a glass plate and dried to produce the electrolyte layer 5. [ Then, the electrolyte layer 5 is pressed onto the negative electrode layer 6 of the negative electrode structure.

Then, a solid battery 1 is produced by squeezing a sheet formed from the anode structure, the electrolyte layer 5 and the cathode structure.

The present invention will be described in more detail by way of the following examples and comparative examples. However, the examples are for illustrating the present invention, and the scope of the present invention is not limited thereto.

<Examples>

Next, an embodiment of the present embodiment will be described. Incidentally, the operations of each of the following examples and comparative examples were all performed in a drier at a dew point temperature of 55 DEG C or lower.

[Example 1]

[Generation of adhesive layer]

(Hereinafter referred to as binder A) (Asahi Chemical Industry Co., Ltd., hereinafter referred to as &quot; Asahi Kasei SOE1611 &quot;) as the adhesive layer conductive material and graphite (Timcal KS- (Hereinafter referred to as Binder B) (Kureha K9200, hereinafter the same) were weighed in a weight% ratio of 60: 10: 15: 15 as the second binder and acid-modified PVDF as the second binder. Then, the above materials and an appropriate amount of NMP were put into a revolving mixer and stirred at 3000 rpm for 5 minutes to produce an adhesive layer coating solution.

Next, an aluminum foil current collector having a thickness of 20 占 퐉 was disposed as a positive electrode current collector 2 on a desktop screen printer (manufactured by Newlong Precision Industries Co., Ltd., the same applies hereinafter), and an adhesive layer coating liquid Lt; / RTI &gt; Then, the positive electrode current collector 2 coated with the adhesive layer coating solution was vacuum-dried at 80 DEG C for 12 hours. Thus, the adhesive layer 3 was formed on the positive electrode current collector 2. The thickness of the adhesive layer 3 after drying was 7 占 퐉.

[Formation of anode layer]

LiNiAlO ₂ ternary powder as a positive electrode active material, vapor-grown carbon fiber powder as a positive electrode layer conductive material (conductive auxiliary agent) Li ₂ SP ₂ S ₅ (80:20 mol%) as a sulfide solid electrolyte and a mass of 60:35:5 % Ratio, and these were mixed using a rotation-type static mixer.

The sulfide-based solid electrolyte was formed by mixing an amorphous material and a crystalline material at a ratio (weight%) of 20:80. The amorphous body is produced by subjecting Li ₂ SP ₂ S ₅ (80:20 mol%) to mechanical milling (MM treatment) at 200 rpm for 30 minutes. The amorphous body is calcined in nitrogen at 205 ° C. for 1 hour .

Next, the primary mixed solution was adjusted to such a mixed powder by adding a xylene solution in which the binder A as the anode layer binder was dissolved so as to be 1.0 wt% with respect to the total weight of the binder A mixed powder. To this mixed solution, an appropriate amount of dehydrated xylene for viscosity adjustment was added to produce a secondary mixed solution. Further, in order to improve the dispersibility of the mixed powder, zirconia balls having a diameter of 5 mm were charged into the secondary mixture so that the voids, the mixed powder, and the zirconium oxide balls accounted for 1/3 of the total volume of the kneading vessel, respectively. The tertiary mixture thus produced was poured into a revolving mixer and stirred at 3000 rpm for 3 minutes to produce a positive electrode coating solution.

Subsequently, a sheet made of the positive electrode collector 2 and the adhesive layer 3 was placed on a desk-top screen printer, and a positive electrode layer coating liquid was coated on the sheet using a metal mask of 150 mu m. Thereafter, the sheet coated with the positive electrode layer coating liquid was dried on a hot plate at 40 DEG C for 10 minutes, followed by vacuum drying at 40 DEG C for 12 hours. Thus, the positive electrode layer 4 was formed on the adhesive layer 3. The total thickness of the cathode current collector 2, the adhesive layer 3, and the anode layer 4 after drying was about 165 占 퐉.

Subsequently, a sheet produced from the positive electrode collector 2, the adhesive layer 3, and the positive electrode layer 4 was rolled by using a roll press machine having a roll gap of 10 占 퐉 to produce a positive electrode structure. The thickness of the anode structure was about 120 탆.

[Generation of cathode layer]

A binder A as a first binder and Li ₂ SP ₂ S ₅ (70:30 mol%) as a sulfide-based solid electrolyte were mixed in a ratio of 69.0: 1.0: 30.0 as a negative electrode active material (vacuum dried at 80 ° C for 24 hours) Weight ratio. Then, this material and an appropriate amount of xylene were put into a revolving mixer, stirred at 3000 rpm for 3 minutes, and defoamed for 1 minute to produce a negative electrode coating liquid. The ratio of amorphous to crystalline in the sulfide-based solid electrolyte was the same as that of the positive electrode.

Next, a copper foil collector having a thickness of 16 mu m was prepared as the negative electrode collector 7, and the negative electrode layer coating liquid was coated on the copper foil collector using a blade. The thickness (gap) of the negative electrode layer coating liquid on the copper foil collector was about 150 mu m.

The sheet coated with the negative electrode layer coating solution was placed in a dryer heated at 80 캜 and dried for 20 minutes. Thereafter, the sheet produced from the negative electrode collector 7 and the negative electrode layer 6 was rolled by a roll press machine having a roll gap of 10 mu m to produce a negative electrode structure. The thickness of the cathode structure was about 100 탆.

[Generation of electrolyte layer]

A xylene solution of the binder A (electrolyte binder) was added to Li ₂ SP ₂ S ₅ (70:30 mol%) as a sulfide-based solid electrolyte so that the binder A was 1 wt% based on the weight of the amorphous powder , And the primary mixture was adjusted. To this primary mixed solution, an appropriate amount of dehydrated xylene which is advantageous for viscosity control was added to produce a secondary mixed solution. Further, in order to improve the dispersibility of the mixed powder, zirconium oxide balls having a diameter of 5 mm were charged into the secondary mixture so that the space, the mixed powder and the zirconium oxide balls each occupy 1/3 of the total volume of the kneading container. The tertiary mixture thus produced was charged in a revolving mixer and stirred at 3000 rpm for 3 minutes to produce an electrolyte layer coating solution. The ratio of amorphous to crystalline was 80:20 in the sulfide solid electrolyte of the solid electrolyte layer.

Next, a glass plate was placed on a desk-top screen printer, and an electrolyte layer coating liquid was coated on the cathode structure using a metal mask of 200 mu m. Thereafter, the sheet coated with the electrolyte layer coating solution was dried with a hot plate at 40 DEG C for 10 minutes, followed by vacuum drying at 40 DEG C for 12 hours. Thus, an electrolyte layer 5 was obtained. The thickness of the electrolyte layer 5 after drying was about 130 탆. Next, the electrolyte layer 5 and the negative electrode layer 6 of the negative electrode structure were adhered by a dry lamination method using a roll press machine having a roll gap of 30 탆 to form an electrolyte layer 5 on the negative electrode structure .

[Generation of solid battery]

A sheet and an anode structure composed of a cathode structure and an electrolyte layer 5 were each cut with a Thomson blade and the electrolyte layer 5 of the sheet and the anode layer 4 of the anode structure were laminated by dry lamination using a roll press having a roll gap of 50 [ (Single cell) of the solid-state cell 1 was produced.

[Example 2 and Comparative Examples 1 to 12]

The ratio of the amorphous substance to the crystalline substance to the sulfide-based solid electrolyte in each of the positive electrode, the electrolyte layer and the negative electrode was changed as shown in Table 1 described below to prepare a solid battery (Example 2 and Comparative Examples 1 to 12).

[Battery characteristics test]

The single cell produced as described above was charged at a constant current density of 0.05 mA / cm &lt; ² &gt; by a TOSCAT-3100 charge / discharge evaluation apparatus of the Orientation System, and discharged to measure the discharge capacity (mAh) 4.0V, lower discharge voltage 2.5V). The discharge capacity (mAh / g) at the discharge lower limit voltage of 2.5 V in Examples and Comparative Examples is shown in Table 1 as follows.

[Cycle characteristic test]

A constant current charge / discharge cycle test at room temperature of 0.05 C was carried out to evaluate the capacity retention rate relative to the first discharge capacity. The results of Examples and Comparative Examples are shown in Table 1.

Crystalline / amorphous Discharge capacity
[mAh / g] Capacity retention after 50 cycles
[%] anode solid
Electrolyte layer cathode Example 1 20/80 80/20 20/80 124 77 Example 2 20/80 80/20 - 120 75 Comparative Example 1 100/0 60/40 20/80 53 53 Comparative Example 2 80/20 60/40 20/80 67 67 Comparative Example 3 60/40 60/40 20/80 52 52 Comparative Example 4 0/100 60/40 20/80 81 81 Comparative Example 5 20/80 0/100 20/80 94 81 Comparative Example 6 20/80 20/80 20/80 91 78 Comparative Example 7 20/80 100/0 20/80 98 75 Comparative Example 8 20/80 60/40 80/20 111 55 Comparative Example 9 20/80 60/40 - 102 49

As can be seen from Table 1, when the amorphous material is contained in the solid electrolyte of the positive electrode and the negative electrode and the ratio of the amorphous material in the solid electrolyte of the solid electrolyte layer is larger than that of the positive electrode and the negative electrode, It was confirmed that the cycle life was also good (Example 1).

On the other hand, it was confirmed that when the ratio of the amorphous material in the positive electrode and the negative electrode was low (Comparative Examples 1 to 3), the cycle life was lowered. In Comparative Example 4, since the sulfide-based solid electrolyte of the anode contained no crystalline material, the discharge capacity decreased. However, the cycle life was good. In Comparative Examples 5 and 6, since the ratio of the crystalline body of the solid electrolyte layer was low, the discharge capacity was lowered as compared with Example 1. In Comparative Example 7, since the amorphous substance was not contained in the solid electrolyte layer, the discharge capacity decreased as compared with Example 1. In Comparative Example 8, since the amorphous material in the negative electrode was small, the cycle life was reduced.

While the illustrative embodiments of one aspect have been described in detail above with reference to the accompanying drawings, it is to be understood that one aspect is not limited to the disclosed embodiments. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims and their equivalents. It belongs to the technical scope of the inventive concept. For example, in the embodiments of the technology, it has been described that the positive electrode and the negative electrode contain a solid electrolyte. However, even if the negative electrode does not include a solid electrolyte, the effect of the inventive aspect can be achieved.

Claims (20)

anode; cathode; And a solid electrolyte layer disposed between the anode and the cathode,
At least an anode and a solid electrolyte layer of the anode and the cathode include a sulfide-based solid electrolyte,
Wherein the sulfide-based solid electrolyte comprises an amorphous substance and a crystalline substance,
Wherein the ratio (A) of the amorphous substance in the sulfide-based solid electrolyte contained in at least one of the positive electrode and the negative electrode is higher than the ratio (A ') of the crystalline substance,
(B) of the amorphous body in the sulfide-based solid electrolyte contained in the solid electrolyte layer is lower than the ratio (B ') of the crystalline body. The solid electrolyte battery according to claim 1, wherein the ratio (A) of the amorphous material in the solid electrolyte contained in at least the positive electrode and the negative electrode is higher than the ratio (B) of the amorphous material in the solid electrolyte included in the solid electrolyte layer. The positive electrode according to claim 1, wherein the ratio (A) of the amorphous body in the solid electrolyte contained in at least the positive electrode and the negative electrode and the ratio (B) of the amorphous body in the solid electrolyte contained in the solid electrolyte layer satisfy 0.1? B? Solid state batteries. The solid battery according to claim 1, wherein the ratio (A) of the amorphous body in the solid electrolyte contained in at least one of the positive electrode and the negative electrode is 0.5 < The solid battery according to claim 1, wherein the ratio (A) of amorphous bodies in the solid electrolyte contained in at least one of the positive electrode and the negative electrode is 0.7 < A < 0.9. The solid electrolyte battery according to claim 1, wherein the ratio (B) of the amorphous body in the solid electrolyte contained in the solid electrolyte layer is 0.1? B < 0.5. The solid battery according to claim 1, wherein a ratio (B) of the amorphous body in the solid electrolyte contained in the solid electrolyte layer is 0.1 < B < 0.3. The solid battery according to claim 1, wherein the sulfide-based solid electrolyte is formed from a mixture of lithium sulfide and phosphorus sulfide. The solid battery according to claim 1, wherein the sulfide-based solid electrolyte comprises Li ₂ SP ₂ S ₅ . The solid electrolyte battery according to claim 8, wherein the ratio (A1) of lithium sulfide in the solid electrolyte contained in the anode is higher than the ratio (B1) of lithium sulfate in the solid electrolyte contained in each of the anode and the solid electrolyte layer. The lithium secondary battery according to claim 8, wherein the ratio (A1) of the lithium sulfide in the solid electrolyte contained in the anode and the ratio (B1) of lithium sulfide in the solid electrolyte contained in each of the anode and the solid electrolyte layers are 0.6? B1? A1? battery. The solid battery according to claim 8, wherein the ratio (A1) of lithium sulfide in the solid electrolyte contained in the anode is 0.70? A1? 0.85. The solid battery according to claim 8, wherein a ratio (B1) of lithium sulfide contained in each of the negative electrode and the solid electrolyte layer is 0.60? B < The solid battery according to claim 1, wherein the anode includes a positive electrode collector and a positive electrode layer. 15. The solid state battery according to claim 14, further comprising an adhesive layer between the positive electrode collector and the positive electrode layer. 14. The solid battery according to claim 13, wherein the content of the sulfide-based solid electrolyte in the anode layer is 20 to 50% by weight based on the total weight of the anode layer. The solid battery according to claim 1, wherein the negative electrode comprises a negative electrode collector and a negative electrode layer. The solid battery according to claim 17, wherein the content of the sulfide-based solid electrolyte in the negative electrode layer is 0 to 40% by weight based on the total weight of the negative electrode layer. The solid battery according to claim 1, wherein the content of the sulfide-based solid electrolyte in the solid electrolyte layer is 95 to 99.9% by weight based on the total weight of the solid electrolyte layer. The solid battery according to claim 1, wherein the solid electrolyte layer has a lithium ion conductivity higher than that of the positive electrode and the negative electrode.

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