JP2013149433A - Electrode member, all-solid-state battery and manufacturing method of electrode member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode member which can be used in an all-solid-state battery, for example, and in which the interface resistance of an electrode active material and a solid electrolyte material is reduced.SOLUTION: The electrode member has an electrode active material containing at least an Melement (Mis a tetravalent element belonging to a group 3-15), and a solid electrolyte material containing at least Li and an Melement (Mis a tetravalent element belonging to a group 3-15 and different from the Melement). In a region where the electrode active material and the solid electrolyte material come into contact, an A element (A is a tetravalent element belonging to a group 3-15 and different from the Melement and the Melement) is solid-dissolving in a site of the Melement of the electrode active material, and a site of the Melement of the solid electrolyte material.

Description

  The present invention relates to an electrode member with reduced interface resistance used for, for example, an all solid state battery.

  With the rapid spread of information-related equipment and communication equipment such as personal computers, video cameras, and mobile phones in recent years, development of batteries that are used as power sources has been regarded as important. Also in the automobile industry and the like, development of high-power and high-capacity batteries for electric vehicles or hybrid vehicles is being promoted. Currently, lithium batteries are attracting attention among various batteries from the viewpoint of high energy density.

  Since lithium batteries currently on the market use an electrolyte containing a flammable organic solvent, it is possible to install safety devices that suppress the temperature rise during short circuits and to improve the structure and materials to prevent short circuits. Necessary. On the other hand, an all-solid lithium battery in which the electrolyte is changed to a solid electrolyte layer to make the battery all solid does not use a flammable organic solvent in the battery. It is considered to be excellent in productivity.

An all-solid lithium battery generally includes a positive electrode active material layer containing a positive electrode active material, a negative electrode active material layer containing a negative electrode active material, and a solid electrolyte layer formed between the positive electrode active material layer and the negative electrode active material layer And have. For example, Patent Document 1 discloses a battery having a laminated structure obtained by laminating and baking a positive electrode layer, a solid electrolyte layer containing LAGP, and a negative electrode layer. By having the laminated structure, the thickness of the electrolyte part is thin, the resistance of the electrolyte part is reduced, and the internal resistance of the battery is reduced, and the productivity can be further improved. Patent Document 2 discloses a lithium battery including a positive electrode formed by mixing an nV-class positive electrode material and an (n + 1) V-class positive electrode material, and LiNi _0.5 Mn as a 5V-class positive electrode material. _1.5 O ₄ is disclosed.

Patent Document 3 discloses Li _{1 + X} Al _X (Ge ₂₎ as a lithium ion conductive glass ceramic obtained by precipitating a crystal phase obtained by subjecting an original glass containing a specific composition to a heat treatment step after melt molding. _{-Y Ti Y) 2-X (} PO 4) 3 are disclosed. Patent Document 4 discloses a secondary battery including a positive electrode active material having an average discharge potential of 4.5 V or higher with respect to Li metal and an electrolytic solution, and the electrolytic solution includes a high dielectric constant solvent, A battery including at least one solvent of dimethyl carbonate or ethyl methyl carbonate is disclosed, and LiNi _0.5 Mn _1.35 Ti _0.15 O ₄ is disclosed as the positive electrode active material. Further, in Patent Document 5, a positive electrode layer containing a positive electrode active material having on its surface solid powder containing primary particles containing a crystalline or amorphous lithium ion conductive solid electrolyte and a crystalline electrolyte decomposition inhibitor; A lithium battery having a negative electrode layer and an organic electrolyte disposed so as to be in contact with the positive electrode active material having the solid powder on the surface is disclosed. As an example, LAGP is used as a solid electrolyte, and TiO ₂ is used as a decomposition inhibitor. The lithium battery used is described.

JP 2010-225390 A JP 2001-043859 A Japanese Patent Laid-Open No. 11-157872 JP 2004-014270 A JP 2008-226463 A

  The conventional all solid state battery has a problem that the interface resistance between the electrode active material and the solid electrolyte material is large. The present invention has been made in view of the above problems, and has as its main object to provide an electrode member that can be used for, for example, an all-solid battery and has reduced interface resistance between the electrode active material and the solid electrolyte material. .

In order to achieve the above object, in the present invention, an electrode active material containing at least M ₁ element (M ₁ is a tetravalent element belonging to Group 3 to Group 15), and at least Li and M A solid electrolyte material containing _two elements (M ₂ is an element different from M ₁ and a tetravalent element belonging to Group 3 to Group 15), in the electrode active material and a region in which the solid electrolyte material is in contact with the site of the M ₁ element of the electrode active material, and the M ₂ element site of the solid electrolyte material, a element (a is the M ₁ element and the a element other than M ₂ elements, group 3 to group is a tetravalent element belonging to group 15.) to provide an electrode member, characterized in that in solid solution.

According to the present invention, in the region where the electrode active material and the solid electrolyte material are in contact with each other, the element A is dissolved in the M ₁ element site of the electrode active material and the M ₂ element site of the solid electrolyte material. Therefore, an electrode member with reduced interface resistance between the electrode active material and the solid electrolyte material can be obtained.

In the above invention, the ionic radius of the A element and _{R A,} the ion radius of the _{M 1} element and _{R M1,} the ion radius of the _{M 2} element case of the _{R M2,} the (R A _{-R M1) A} value obtained by dividing the absolute value by R _A and a value obtained by dividing the absolute value of (R _A −R _M2 ) by R _A are preferably 20% or less. This is because the A element is easily dissolved in the M ₁ element site of the electrode active material and the M ₂ element site of the solid electrolyte material, and the effects of the present invention are further exhibited.

  In the said invention, it is preferable to have the modifier containing the said A element in the interface of the said electrode active material and the said solid electrolyte. This is because the interface resistance can be further reduced.

  In the said invention, it is preferable that the electrode member mentioned above is a particulate form.

  In the said invention, it is preferable that the electrode member mentioned above is an electrode active material layer containing the said electrode active material and the said solid electrolyte material.

  In the above invention, the electrode member described above is composed of an electrode active material layer and a solid electrolyte layer, the electrode active material layer contains the electrode active material, and the solid electrolyte layer contains the solid electrolyte material. Is preferred.

  In the present invention, a positive electrode active material layer containing a positive electrode active material, a negative electrode active material layer containing a negative electrode active material, a solid electrolyte layer formed between the positive electrode active material layer and the negative electrode active material layer, An all-solid-state battery comprising the electrode member described above is provided.

  According to this invention, since the electrode member mentioned above is used, it can be set as the all-solid-state battery which reduced the interface resistance of an electrode active material and a solid electrolyte material.

In the present invention, an electrode active material containing at least M ₁ element (M ₁ is a tetravalent element belonging to Group 3 to Group 15), and at least Li and M ₂ elements (M ₂ is A solid electrolyte material containing an element different from M ₁ and a tetravalent element belonging to Group 3 to Group 15. the interface between the material and the solid electrolyte material, a element (a is an element other than the M ₁ element and the M ₂ element and a tetravalent element belonging to group 3 to group 15 group.) containing a preparation step of preparing a precursor member having a modified material that, in the precursor member heat-treated, the site of the M ₁ element of the electrode active material and the M ₂ element site of the solid electrolyte material, the element a A heat treatment step for solid solution To provide a manufacturing method of an electrode member, characterized in that.

According to the present invention, by heat-treating the precursor member, in the region where the electrode active material and the solid electrolyte material are in contact with each other, the element A contained in the modifier is changed to the element M _{1 of the} electrode active material. And the M ₂ element site of the solid electrolyte material. Therefore, an electrode member with reduced interface resistance between the electrode active material and the solid electrolyte material can be obtained.

  In the said invention, it is preferable that the said modifier is an oxide. It is because it can be set as the electrode member which can reduce the interface resistance of an electrode active material and a solid electrolyte material more.

In the above invention, the modified material is preferably a TiO _2. This is because the electrode member has a high relative dielectric constant and can further reduce the interface resistance.

  In this invention, there exists an effect that the electrode member which reduced the interface resistance of an electrode active material and a solid electrolyte material can be obtained.

It is a schematic sectional drawing which shows an example of the area | region where the electrode active material and solid electrolyte material in the electrode member of this invention contact. It is a schematic sectional drawing which shows an example of the area | region where the electrode active material and solid electrolyte material in the conventional electrode member contact. It is a schematic sectional drawing which shows an example of the electrode member of this invention. It is a schematic sectional drawing which shows an example of the all-solid-state battery of this invention. 2 is an XRD measurement result of an electrode member obtained in Example 1. FIG. 4 is an XRD measurement result of an evaluation battery obtained in Comparative Example 1. 4 is a graph showing peak current values of evaluation batteries obtained in Examples 2 to 6 and Comparative Example 1. FIG.

  Hereinafter, the electrode member, the all-solid battery, and the method for producing the electrode member of the present invention will be described in detail.

A. Electrode Member The electrode member of the present invention includes an electrode active material containing at least M ₁ element (M ₁ is a tetravalent element belonging to Group 3 to Group 15), and at least Li and M ₂ elements (M ₂ is an element different from M ₁ and is a tetravalent element belonging to Group 3 to Group 15.), and an electrode member having the electrode active material And in the region where the solid electrolyte material is in contact with the M ₁ element site of the electrode active material and the M ₂ element site of the solid electrolyte material, the A element (A is the M ₁ element and the M ₂ element). Is a tetravalent element belonging to Group 3 to Group 15), and is a solid solution.

According to the present invention, in the region where the electrode active material and the solid electrolyte material are in contact with each other, the element A is dissolved in the M ₁ element site of the electrode active material and the M ₂ element site of the solid electrolyte material. Therefore, an electrode member with reduced interface resistance between the electrode active material and the solid electrolyte material can be obtained. Further, as described above, the A element is dissolved in the M ₁ element site and the M ₂ element site, that is, the modifier containing the A element is used as the electrode active material and the solid electrolyte material. By interdiffusion, excellent adhesion can be exhibited at the interface between the electrode active material, the modifier, and the solid electrolyte material.

FIG. 1 is a schematic cross-sectional view showing an example of an electrode member of the present invention. As shown in FIG. 1A, an electrode member 10 of the present invention has an electrode active material 1 and a solid electrolyte material 2, and although not shown, a region where the electrode active material 1 and the solid electrolyte material 2 are in contact with each other. in 4, M ₁ element site of the electrode active material 1, and M ₂ element site of the solid electrolyte material, the above-mentioned element a is a solid solution. Moreover, you may have the oxide 3 containing the A element mentioned above in the interface of the electrode active material 1 and the solid electrolyte material 2. FIG. Further, FIG. 1B is a schematic diagram showing a region 4 in which the electrode active material 1 and the solid electrolyte material 2 in FIG. As shown in FIG. 1B, the electrode active material 1 (for example, LiNi _0.5 (Mn—Ti) _1.5 O ₄ ) and the solid electrolyte material 2 (for example, Li _1.5 Al _0.5 (Ge—Ti). In the region 4 where _1.5 (PO ₄ ) ₃ ) is in contact with the M ₁ element (Mn) site contained in the electrode active material and the M ₂ element (Ge) site contained in the solid electrolyte material, Element A (Ti) is dissolved.

As shown in FIG. 2, the conventional electrode member includes an electrode active material (for example, LiNi _0.5 Mn _1.5 O ₄ ) and a solid electrolyte material (for example, Li _3.5 Si _0.5 P _0.5 O ₄ ). In the region where the electrode contacts, an intermediate layer, which is a reaction product (for example, Li ₃ PO ₄ ) that contributes to the charge / discharge reaction, was formed to reduce the interface resistance between the electrode active material and the solid electrolyte material. However, by the interface is increased by the intermediate layer is formed (the intermediate layer becomes resistance phase), there is a problem that the interfacial resistance is increased, further degradation of the electrode active material (e.g., LiNi _0.18 Mn _Since a so-called heterogeneous phase such as _1.82 O ₄ ) is formed, the interface between the electrode active material and the solid electrolyte material further increases, resulting in a higher interface resistance.

In contrast, in the present invention, the site of the M ₁ element of the electrode active material, and the M ₂ element site of the solid electrolyte material, since the element A is a solid solution, the electrode active material and a solid In the region where the electrolyte material is in contact, a resistance phase such as an intermediate layer or a different phase as described above is not formed, and the interface resistance between the electrode active material and the solid electrolyte material can be reduced. The fact that the A element is dissolved in the M ₁ element site of the electrode active material and the M ₂ element site of the solid electrolyte material is, for example, from the X-ray diffraction (XRD) measurement result of the electrode. This can be confirmed by determining the lattice constants of the active material and the solid electrolyte material.

Here, the region where the electrode active material and the solid electrolyte material are in contact with each other is a region where the element A can be dissolved, and includes the interface between the electrode active material and the solid electrolyte material and the vicinity of the interface. The region is appropriately set according to the types of the electrode active material and the solid electrolyte material, and the heat treatment conditions (temperature, time, etc.), but from the interface between the electrode active material and the solid electrolyte material, A region of about 1 nm to 2000 nm in the thickness direction and a region of about 1 nm to 2000 nm in the thickness direction of the solid electrolyte material from the interface between the electrode active material and the solid electrolyte material are included.
Hereinafter, the electrode member of the present invention will be described for each configuration.

1. Electrode Active Material The electrode active material used for the electrode member of the present invention contains at least M ₁ element (M ₁ is a tetravalent element belonging to Group 3 to Group 15), and is a solid electrolyte. In the region in contact with the material, at the site of the M ₁ element, the A element (A is an element different from the M ₁ element and the M ₂ element, and is a tetravalent element belonging to Group 3 to Group 15. .) Is a solid solution. Such an electrode active material may be a positive electrode active material or a negative electrode active material, but among them, a positive electrode active material is preferable.

The M ₁ element is not particularly limited as long as it is a tetravalent element belonging to Group 3 to Group 15, but a transition metal element can be suitably used. Such _{M 1} element, for example Mn, V, Zr, Si, Ge, can be mentioned Sn, and among them Mn, Sn can be suitably used, can be used more particularly preferably the Mn .

As an example of the electrode active material used in the present invention, an electrode active material containing tetravalent Mn (hereinafter, may be referred to as an Mn (IV) -containing electrode active material) is mentioned. Examples of the Mn (IV) -containing electrode active material include a Mn (IV) -containing electrode active material having a spinel structure. A typical example of the Mn (IV) -containing electrode active material having the spinel structure is LiMn ₂ O ₄ . Note that the Mn element in LiMn ₂ O ₄ is a mixed state of trivalent and tetravalent Mn elements.

  As the Mn (IV) -containing electrode active material having the spinel structure, a part of Mn may be substituted with another element. Such an element is at least one selected from the group consisting of Ni, Co, Ti, and Zr, and is preferably one selected from the group consisting of Ni, Co, and Ti, and is preferably Ni. Is particularly preferred. When substituting the Mn (IV) -containing electrode active material having a spinel structure with the above-mentioned other elements, the ratio of Mn to the total of Mn and the elements substituting Mn is preferably 50% or more, and in particular, 60% More preferably. Specifically, when the element replacing Mn is Ni, the ratio of Mn to the total of Mn and Ni is not particularly limited as long as it is 50% or more, but 75% is particularly preferable. This is because the electrode member can be operated at a high potential (for example, 5V class).

As a spinel type Mn (IV) -containing electrode active material in which a part of Mn contained in such an electrode active material is substituted with another element, for example, LiNi _0.5 Mn _1.5 O ₄ , LiCr _0.05 Ni _0.5 Mn _1.45 O ₄ , LiCo _0.1 Ni _0.5 Mn _1.4 O _{4 and the} like.

Examples of Mn (IV) -containing electrode active materials other than the spinel structure used in the present invention include LiNi _0.33 Co _0.33 Mn _0.33 O ₂ and Li ₂ MnO ₃ —LiNi _0.5 Mn _{0. .5} O ₂ solid solution.

The electrode active material in the present invention, in a region in contact with solid electrolyte material to the site of the above-mentioned M ₁ element, in which element A is a solid solution. Such an element A, an element different between the M ₁ element, but the present invention is not particularly limited as long as it is a tetravalent element belonging to Group 3 to Group 15 Group, for example Ti, Si, Zr, Ge Etc.

The M ₁ element and element A contained in the electrode active material of the present invention is a tetravalent element such as described above, but are not particularly limited as long as it is mutually different elements, the above-mentioned element A the ionic radius and _{R a,} if the ionic radius of _{M 1} element was _{R M1,} preferably made of a (R a _{-R M1)} of a value obtained by dividing the absolute value _{R a} of 20% or less, among others, 15 % Or less is more preferable, and 10% or less is particularly preferable. When the value obtained by dividing the absolute value of (R _A -R _M1 ) by R _A is larger than the above range, the above-described A element is dissolved in the M ₁ element site in the region where the electrode active material and the solid electrolyte material are in contact with each other. It is because it may become difficult to do. Such M ₁ element and the element A, above value is not particularly limited as long as it is within a specific range, in order to further improve the effect of the electrode member of the present invention is chosen to be a preferred combination It is preferable. Specifically, when _{M 1} element is Mn, A element Ti, Si, Zr, is preferably Ge, and more preferably among them Ti.

  The shape of the electrode active material can be appropriately selected according to the shape of the electrode member of the present invention, and examples thereof include particles such as true spheres and ellipsoids, and thin film shapes.

2. Next, the solid electrolyte material used for the electrode member of the present invention will be described. The solid electrolyte material contains Li and M ₂ element (M ₂ is an element different from M ₁ and is a tetravalent element belonging to Group 3 to Group 15). The region in contact with the electrode active material is not particularly limited as long as the element A described above is dissolved in the M ₂ element site. As such a solid electrolyte material, for example, an oxide solid electrolyte material and a sulfide solid electrolyte material can be used. Moreover, it is preferable that the solid electrolyte material used for this invention is selected so that it may become a suitable combination with the electrode active material mentioned above from a viewpoint of the effect improvement of an electrode member. Suitable combinations of the electrode active material and the solid electrolyte material include, for example, a combination of an oxide electrode active material and an oxide solid electrolyte material, and a combination of an oxide electrode active material and a sulfide solid electrolyte material. it can.

The M ₂ element is not particularly limited as long as it is a tetravalent element that is different from M ₁ and belongs to Group 3 to Group 15. For example, Ge, Ti, Si, Zr Sn and the like can be mentioned. Among these, Ge and Ti can be preferably used.

As an example of the solid electrolyte material used in the present invention, a solid electrolyte material containing tetravalent Ge (hereinafter sometimes referred to as a Ge (IV) -containing solid electrolyte material) may be mentioned. Examples of such a Ge (IV) -containing solid electrolyte material include oxide solid electrolytes such as NASICON compounds represented by the general formula Li _{1 + x} Al _x Ge _2-x (PO ₄ ) ₃ (0 ≦ x ≦ 2). Materials can be mentioned.

In the NASICON type compound represented by the general formula Li _{1 + x} Al _x Ge _2-x (PO ₄ ) ₃ (0 ≦ x ≦ 2), the range of x may be 0 or more, and in particular, it may be larger than 0. Preferably, it is 0.3 or more. On the other hand, the range of x may be 2 or less, and is preferably 1.7 or less, and more preferably 1 or less. Above all, in the present invention, the Ge (IV) containing a solid electrolyte _{material, Li 1.5 Al 0.5 Ge 1.5 (} PO 4) is preferably _3.

Examples of the Ge (IV) containing a solid electrolyte material, for _{example, Li 2 S-GeS 2,} Li 2 S-P 2 S 5 -Ge m S n ( however, m, n is a positive number.) Sulfide such as A solid electrolyte material can also be used. The description of “Li ₂ S—GeS ₂ ” means a sulfide solid electrolyte material using a raw material composition containing Li ₂ S and GeS ₂ , and the same applies to other descriptions.

Another example of the solid electrolyte material used in the present invention is a solid electrolyte material containing tetravalent Ti (hereinafter sometimes referred to as a Ti (IV) -containing solid electrolyte material). it can. As such a Ti (IV) -containing solid electrolyte material, for example, a NASICON compound represented by the general formula Li _{1 + x} Al _x Ti _2-x (PO ₄ ) ₃ (0 ≦ x ≦ 2), Li _0.33 La _0.56 TiO ₃ etc. can be mentioned.

In the NASICON type compound represented by the general formula Li _{1 + x} Al _x Ti _2-x (PO ₄ ) ₃ (0 ≦ x ≦ 2), the range of x may be 0 or more, and in particular, it must be greater than 0. Is more preferable and 0.3 or more is more preferable. On the other hand, the range of x may be 2 or less, and is preferably 1.7 or less, and more preferably 1 or less. Above all, in the present invention, the Ti (IV) containing a solid electrolyte _{material, Li 1.3 Al 0.3 Ti 1.7 (} PO 4) is preferably _3.

Examples of the Ti (IV) containing a solid electrolyte material, for _example, can also be used sulfide-based solid electrolyte material, such as Li ₂ S-TiS 2.

Another example of the solid electrolyte material used in the present invention is a solid electrolyte material containing tetravalent Si (hereinafter sometimes referred to as a Si (IV) -containing solid electrolyte material). it can. As such a Si (IV) -containing solid electrolyte material, for example, an oxide solid electrolyte material can be used, and specifically, Li ₃ Si _0.5 P _0.5 O _{4 and the} like can be mentioned.

Examples of the Si (IV) containing a solid electrolyte material, for example, can be used sulfide-based solid electrolyte material, _{specifically, 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-SiS 2 -Li ₃ PO ₄ , Li ₂ S—SiS ₂ —Li _x MO _y (where x and y are positive numbers, and M is any one of P, Si, Ge, B, Al, Ga, and In). be able to.

The M ₂ element, chosen such is a different element as M ₁ element contained in the electrode active material described above, from the viewpoint of enhancing the effect of the electrode member of the present invention, a suitable combination and M ₁ element It is preferred that Specifically, when the above-mentioned M ₁ element is Mn, preferably the M ₂ element is Ge or Ti, more preferably among them Ge.

In the solid electrolyte material according to the present invention, the element A is dissolved in the M ₂ element site in the region in contact with the above-described electrode active material. Such an element A, an element different between the M ₁ element and the M ₂ element, but the present invention is not particularly limited as long as it is a tetravalent element belonging to Group 3 to Group 15 Group The "1 The same thing as what was described in ". Electrode active material" can be mentioned.

The M ₂ element and element A contained in the electrode active material of the present invention, as described above, is a tetravalent element, but is not particularly limited as long as it is mutually different elements, above element A the ionic radius and _{R a,} if the ion radius of _{M 2} element was _{R M2,} preferably made of a (R a _{-R M2)} of a value obtained by dividing the absolute value _{R a} of 20% or less, among others, What becomes 15% or less is more preferable, and what becomes 10% or less is especially preferable. When the value obtained by dividing the absolute value of (R _A -R _M2 ) by R _A is larger than the above range, the above-described A element is dissolved in the M ₂ element site in the region where the electrode active material and the solid electrolyte material are in contact with each other. It is because it may become difficult to do. The M ₂ element and the A element are not particularly limited as long as the above-described values are within a specific range, but are selected to be a suitable combination from the viewpoint of further enhancing the effect of the electrode member of the present invention. It is preferable. Specifically, if _{M 2} element is Ge, A element Ti, Si, is preferably Zr, and more preferably among them Ti.

  The shape of the solid electrolyte material is appropriately selected according to the shape of the electrode member of the present invention, and examples thereof include particles such as true spheres and ellipsoids, and thin film shapes.

3. Electrode Member The electrode member of the present invention is not particularly limited as long as it has the electrode active material and the solid electrolyte material, but the electrode active material is present at the interface between the electrode active material and the solid electrolyte material. It is preferable to have a modifier containing an element A that is dissolved in the solid electrolyte material.

  The modifying material contains the element A described above, and preferably has a higher dielectric constant than the above-described solid electrolyte material. This is because by having such a modifier at the interface, the interface resistance between the electrode active material and the solid electrolyte material can be further reduced. As a method for measuring the relative dielectric constant, for example, a method described in JIS C 2565 (such as a cavity resonator method) or a method obtained by improving the method described in JIS C 2565 as a closed sample insertion hole (sample insertion) Hole closed perturbation type cavity resonator method). Specifically, the dielectric constant can be calculated by inserting a sample into the cavity resonator and measuring the change in the resonance frequency before and after inserting the sample. Further, the ratio (B / A) of the relative dielectric constant (B) of the solid electrolyte material to the relative dielectric constant (A) of the modifier is not particularly limited as long as the effect of the present invention can be obtained. , Preferably in the range of 0.001-1, more preferably in the range of 0.005-0.5, and particularly preferably in the range of 0.01-0.1.

  A mechanism that can reduce the interfacial resistance in the electrode active material and the solid electrolyte material by containing the modifier is considered as follows. That is, a modifier having a relatively high dielectric constant is disposed at the interface between the electrode active material and the solid electrolyte material, so that, for example, when used in an all-solid battery, an extremely large electric field applied to the interface during charge / discharge is reduced. It is considered that the formation of a carrier-deficient layer (for example, a lithium-deficient layer) on the solid electrolyte material side of the interface can be suppressed. In general, at the interface between the electrode active material and the solid electrolyte material, a large local electric field is caused by the potential difference between the two, and a carrier-deficient layer (for example, a lithium-deficient layer, thickness: several nm to several μm) is formed on the solid electrolyte material side. It is thought that it is formed. In such a carrier-deficient layer, the metal concentration in the material is deviated from the optimum composition, so that the ionic conductivity is lowered, and as a result, the interface resistance is considered to increase. Such a carrier-deficient layer is more conspicuous as the potential difference between the electrode active material and the solid electrolyte material is larger. For example, it is considered that the carrier-deficient layer becomes more prominent when the average operating voltage of the positive electrode active material is high.

  On the other hand, when a modifier having a relative dielectric constant higher than that of the solid electrolyte material is disposed at the interface between the electrode active material and the solid electrolyte material, a large local electric field generated by the potential difference between the electrode active material and the solid electrolyte material is relaxed. . Therefore, it is considered that the interfacial resistance is reduced as a result of suppressing the decrease in ion mobility in the carrier-deficient layer. In addition, it is considered that the higher the relative permittivity of the dielectric, the smoother the movement of ions at the interface. Therefore, if the modifier having a relative dielectric constant higher than that of the solid electrolyte material is disposed at the interface between the electrode active material and the solid electrolyte material, the interface resistance between the electrode active material and the solid electrolyte material can be sufficiently reduced. Conceivable.

Examples of the modifier include oxides, sulfides, and nitrides. The oxide used as such a modifier may include Li or may not include Li, but preferably includes Li. It is because it has Li ion conductivity. When the modifier contains Li, for example, lithium titanate (LTO), Li ₄ SiO _{4 and the} like can be mentioned. When the oxide does not contain Li, for example, TiO ₂ , SiO ₂ , ZrO ₂ , SnO _{2 and the} like. In addition, as another example of the modifier, a nitride such as Si ₃ N ₄ can be used.

The modified material, which differs from A elements as described above M ₁ element and M ₂ element is contained, so that from the viewpoint of enhancing the effect of the present invention, a suitable combination and M ₁ element and M ₂ element Is preferably selected. For example, the above-mentioned M ₁ element is Mn, if M ₂ element is Ge, A element contained in the modified material can be selected suitably and Ti. In addition, as an example of the configuration of the electrode member of the present invention having a suitable combination of the M ₁ element, the M ₂ element, and the A element, an electrode active material / modifier / solid electrolyte material is LiNi _0.5 Mn _{1.5 O 4 / TiO 2 / Li 1.5} Al 0.5 Ge 1.5 (PO 4) may be mentioned ₃ become configured.

The modifier is disposed at the interface between the electrode active material and the solid electrolyte material, and is appropriately determined according to the shape of the electrode member of the present invention. Further, the shape of the modifier is appropriately selected according to the shape of the electrode member and the like, and examples thereof include particles such as a true sphere and an ellipsoid, and a thin film. When the modifying material is in the form of particles, the average particle size of the modifying material is not particularly limited as long as the interface resistance can be reduced. In this connection, the measurement method of the average particle diameter, and a method of measuring the D ₅₀ with a flow distribution analyzer.

  The amount of the modifying material contained in the electrode member of the present invention is not particularly limited as long as the resistance at the interface between the electrode active material and the solid electrolyte material can be reduced. The electrode active material and the solid electrolyte used are not limited. It is appropriately determined according to the type of material.

  The electrode member of the present invention is not particularly limited as long as it has at least the electrode active material and the solid electrolyte material described above, but is preferably a sintered body, for example. It is because it can be set as a precise | minute electrode member. Moreover, the electrode member of this invention can be divided roughly as follows based on a shape.

(1) First shape The first shape electrode member is in the form of particles. More specifically, the first shape electrode member is in the form of particles (composite particles) in which the surface of the electrode active material is coated with a solid electrolyte material. FIG. 3A shows an example of the first-shaped electrode member. As shown in FIG. 3A, the electrode member 10 is in the form of particles, and the electrode active material 1 and the solid electrolyte material 2 are separated from each other. Have. The electrode member 10 may have a modifier 3 at the interface between the electrode active material 1 and the solid electrolyte material 2.

As the first shape electrode member, it suffices that at least a part of the surface of the electrode active material is covered with a solid electrolyte material, and the coverage is preferably, for example, 25% or more,
More preferably, it is 50% or more.

The first-shaped electrode member is in the form of particles, and the average particle diameter (D ₅₀ ) thereof is preferably in the range of 0.1 μm to ₅₀ μm, for example. In addition, the said average particle diameter can be determined with a particle size distribution meter, for example.

  The first-shaped electrode member may contain the modifying material described above. The modifier is not particularly limited as long as it is disposed at the interface between the electrode active material and the solid electrolyte material.

  The first shape electrode member is normally used for an all-solid battery, and the all-solid battery will be described in detail in “B. All-solid battery” described later. Further, the method for producing the first shape electrode member is not particularly limited as long as the electrode member having the above-described shape can be obtained. For example, the method described in “C. Method for producing electrode member” described later. Can be used.

(2) Second Shape The second shape electrode member is an electrode active material layer containing an electrode active material and a solid electrolyte material. FIG. 3B shows an example of a second-shaped electrode member. For example, the electrode member 10 is a positive electrode active material layer 11 in an all-solid battery 20 described later, and the positive electrode active material layer 11 is an electrode active material. The substance 1 and the solid electrolyte material 2 are contained. Further, the modifier 3 may be provided at the interface between the electrolyte material 1 and the solid electrolyte material 2. In addition, about each structure of the all-solid-state battery 20, it can be made the same as that of FIG. 4 mentioned later.

  Such a second shape electrode member contains at least an electrode active material and a solid electrolyte material, and the content of the electrode active material in the second shape electrode member is, for example, 10 wt% to 99 wt%. It is preferably within the range, and more preferably within the range of 20% by weight to 90% by weight. The electrode active material is not particularly limited as long as it is in contact with the solid electrolyte material, but it is preferable to carry the solid electrolyte material.

  In addition, the content of the solid electrolyte material in the second shape electrode member can be the same as that of the electrode layer of a general all solid state battery, for example, within the range of 1 wt% to 90 wt%. Is preferable, and it is more preferable that it is in the range of 10 wt% to 80 wt%. When the solid electrolyte material is in the form of particles, the average particle size is preferably in the range of 50 nm to 5 μm, for example, and more preferably in the range of 100 nm to 3 μm.

  The electrode member of the second shape may contain a conductive material as necessary in addition to the electrode active material and the solid electrolyte material described above. Examples of the conductive material include acetylene black, ketjen black, and carbon fiber. Further, the second shape electrode member may further contain a binder. As such a binder, for example, a fluorine-containing binder such as polyvinylidene fluoride (PVDF) or polytetrafluoroethylene (PTFE) can be used.

  The second-shaped electrode member may have the modifying material described above. The position where the modifier is arranged is not particularly limited as long as it is an interface between the electrode active material and the solid electrolyte material. In this case, the modifier may be supported on at least one of the electrode active material and the solid electrolyte material.

  The thickness of the second-shaped electrode member varies depending on, for example, the type of all-solid battery used, and is preferably in the range of 0.1 μm to 1000 μm, for example. Moreover, as a manufacturing method of a 2nd-shaped electrode member, the formation method of the electrode active material layer of a general all-solid-state battery can be used, for example. Specifically, the method described in “C. Electrode member manufacturing method” can be given.

(3) Third Shape The third shape electrode member is composed of an electrode active material layer and a solid electrolyte layer, the electrode active material layer contains the electrode active material described above, and the solid electrolyte layer described above. It is characterized by containing a material. FIG. 3C shows an example of a third shape electrode member. As shown in FIG. 3C, the electrode member 10 includes the positive electrode active material layer 11 and the solid electrolyte layer in the all-solid battery 20. 13. Further, at the interface between the positive electrode active material layer 11 and the solid electrolyte layer 13, the electrode active material (positive electrode active material) 1 and the solid electrolyte material 2 are in contact with each other. Further, the modifier 3 may be provided at the interface between the electrode active material 1 and the solid electrolyte material 2. In addition, about each structure of the all-solid-state battery 20, it can be made the same as that of FIG. 4 mentioned later.

  The electrode active material layer in the third shape electrode member contains at least the electrode active material described above, and the content of the electrode active material in the electrode active material layer is the same as that of the second shape electrode member. The same can be said. In addition, the electrode active material layer of the electrode member in the third shape may contain at least one of a conductive additive and a binder as necessary, in addition to the electrode active material. As the conductive auxiliary agent and the binder, the same electrode members as those of the second shape can be used. In addition, it can be the same as that of the said 2nd shape electrode member about the other matter of the electrode active material layer of a 3rd shape electrode member.

  Further, the solid electrolyte layer in the third shape electrode member is not particularly limited as long as it contains at least the above-described solid electrolyte material. For example, the solid electrolyte layer is preferably composed of only the above-described solid electrolyte material. The thickness of the solid electrolyte layer in the third-shaped electrode member varies depending on the type of the solid electrolyte material and the configuration of the all-solid battery used, but is within the range of, for example, 0.1 μm to 1000 μm. Is preferable, and it is more preferable to be within a range of 0.1 μm to 300 μm.

  The electrode member of the third shape may have the modifying material described above. Examples of the position where the modifier is disposed include the above-described interface between the electrode active material layer and the solid electrolyte layer. For example, the surface coverage of the electrode active material layer by the modifier in a plan view is 1% to 95%. Preferably, it is in the range of 5% to 70%, more preferably in the range of 10% to 50%. The surface coverage is a value that can be calculated from an image obtained by a scanning electron microscope (SEM).

  The method for producing the third shape electrode member is not particularly limited as long as it is a method capable of obtaining the electrode member having the shape described above. For example, the method described in “C. Method for producing electrode member” is used. Can be used.

B. Next, the all solid state battery of the present invention will be described. The all solid state battery of the present invention includes a positive electrode active material layer containing a positive electrode active material, a negative electrode active material layer containing a negative electrode active material, and a solid formed between the positive electrode active material layer and the negative electrode active material layer. An all-solid-state battery having an electrolyte layer, wherein the electrode member described above is used.

The all solid state battery of the present invention can be roughly divided into three modes depending on the shape of the electrode member used.
Hereinafter, the all solid state battery of the present invention will be described separately for each embodiment.

1. First Embodiment A first embodiment of the all solid state battery of the present invention will be described. A first embodiment of the present invention is formed between a positive electrode active material layer containing a positive electrode active material, a negative electrode active material layer containing a negative electrode active material, and the positive electrode active material layer and the negative electrode active material layer. An all-solid battery having a solid electrolyte layer, wherein the electrode member described above is used, and the electrode member is particulate.

  FIG. 4 is a schematic cross-sectional view showing an example of the all solid state battery of the present embodiment. As shown in FIG. 4, the all-solid battery 20 includes a positive electrode active material layer 11, a negative electrode active material layer 12, a solid electrolyte layer 13 formed between the positive electrode active material layer 11 and the negative electrode active material layer 12, A positive electrode current collector 14 that collects current from the positive electrode active material layer 11 and a negative electrode current collector 15 that collects current from the negative electrode active material layer 12 are included. The all solid state battery has a particulate electrode member 10 (see FIG. 3A) on at least one of the positive electrode active material layer 11 and the negative electrode active material layer 12.

  According to this embodiment, since the electrode member described above is used, an all-solid battery capable of reducing the interface resistance at the interface between the electrode active material and the solid electrolyte material can be obtained. Moreover, in the electrode member mentioned above, since the modifying material interdiffuses in the electrode active material and the solid electrolyte material, it exhibits excellent adhesion at the interface of the electrode active material, the modifying material, and the solid electrolyte material. It can be set as the all-solid-state battery excellent in cycling characteristics.

(1) Positive electrode active material layer The positive electrode active material layer in this embodiment is not particularly limited as long as it is a layer containing at least a positive electrode active material. For example, the positive electrode active material layer contains the above-described particulate electrode member. It is preferable.

  Moreover, the positive electrode active material layer in this embodiment may contain at least one of a conductive additive and a binder as necessary. In addition, what was described in the term of "A. Electrode member" can be used for a conductive support agent and a binder.

  The thickness of the positive electrode active material layer varies depending on the type of the all-solid battery intended, but is preferably in the range of 0.1 μm to 1000 μm, for example. Further, the method for forming the positive electrode active material layer is not particularly limited as long as it can form the target positive electrode active material layer.

(2) Solid electrolyte layer The solid electrolyte layer of this embodiment is formed between the positive electrode active material layer and the negative electrode active material layer, and contains at least a solid electrolyte material. The solid electrolyte material contained in the solid electrolyte layer may be the same as or different from the solid electrolyte material used for the electrode member described above, for example.

  In addition, examples of the shape of the solid electrolyte material include particles such as a true sphere and an ellipsoid, and a thin film. Moreover, when a solid electrolyte material is a particulate form, it is preferable that the average particle diameter exists in the range of 50 nm-5 micrometers, for example, and it is more preferable that it exists in the range of 100 nm-3 micrometers.

  The solid electrolyte layer is preferably composed of only the solid electrolyte material described above, but may further contain a binder as necessary. The binder used for the solid electrolyte layer is the same as in the positive electrode active material layer described above. The thickness of the solid electrolyte layer varies greatly depending on the type of the solid electrolyte material and the configuration of the all-solid battery, but is preferably in the range of 0.1 μm to 1000 μm, for example, 0.1 μm to 300 μm. More preferably within the range. The method for forming the solid electrolyte layer is not particularly limited as long as it is a method capable of forming the target solid electrolyte layer.

(3) Negative electrode active material layer The negative electrode active material layer in this embodiment is a layer containing at least a negative electrode active material, and contains at least one of a solid electrolyte material, a conductive additive, and a binder as necessary. You may do it. The negative electrode active material in the all solid state battery of this embodiment is not particularly limited as long as it can occlude / release Li ions, which are conductive ions, and examples thereof include a carbon active material and a metal active material. be able to. Examples of the carbon active material include graphite, mesocarbon microbeads (MCMB), highly oriented graphite (HOPG), hard carbon, and soft carbon. On the other hand, examples of the metal active material include alloy materials such as Li alloy and Sn—Co—C, In, Al, Si, and Sn. In addition, examples of other negative electrode active materials include oxide materials such as Li ₄ TiO ₅ .

  Note that the solid electrolyte material and the conductive agent used in the negative electrode active material layer are the same as those in the positive electrode active material layer and the solid electrolyte layer described above, respectively. The thickness of the negative electrode active material layer is, for example, in the range of 0.1 μm to 1000 μm. The method for forming the negative electrode active material layer is not particularly limited as long as it can form the target negative electrode active material layer.

(4) Other Configurations The all solid state battery of this embodiment has at least the positive electrode active material layer, the solid electrolyte layer, and the negative electrode active material layer described above. Furthermore, it usually has a positive electrode current collector for collecting current of the positive electrode active material layer and a negative electrode current collector for collecting current of the negative electrode active material layer. Examples of the material for the positive electrode current collector include gold, SUS, aluminum, nickel, iron, titanium, and carbon. On the other hand, examples of the material for the negative electrode current collector include gold, SUS, copper, nickel, and carbon. In addition, the thickness and shape of the positive electrode current collector and the negative electrode current collector are preferably appropriately selected according to the use of the all solid state battery. Moreover, the battery case used for a general all-solid battery can be used for the battery case used for this embodiment, For example, the battery case made from SUS etc. can be mentioned. Moreover, the all-solid-state battery of this embodiment may have a power generating element formed inside an insulating ring.

(5) All-solid-state battery As a kind of all-solid-state battery of this embodiment, although a primary battery may be sufficient, for example, a secondary battery may be sufficient, it is preferable that it is a secondary battery. This is because it can be repeatedly charged and discharged and is useful, for example, as an in-vehicle battery. Examples of the shape of the all solid state battery of this embodiment include a coin type, a laminate type, a cylindrical type, and a square type. Moreover, the manufacturing method of the all-solid-state battery of this embodiment will not be specifically limited if it is a method which can obtain the all-solid-state battery mentioned above, The method similar to the manufacturing method of a general all-solid-state battery is used. Can be used.

2. Second Embodiment A second embodiment of the all solid state battery of the present invention will be described. The second embodiment includes a positive electrode active material layer containing a positive electrode active material, a negative electrode active material layer containing a negative electrode active material, and a solid electrolyte layer formed between the positive electrode active material layer and the negative electrode active material layer The electrode member described above is used, and the electrode member is an electrode active material layer containing an electrode active material and a solid electrolyte material.

  The all solid state battery of this embodiment is formed between the positive electrode active material layer 11, the negative electrode active material layer 12, the positive electrode active material layer 11 and the negative electrode active material layer 12, as shown in FIG. It has a solid electrolyte layer 13, a positive electrode current collector 14 that collects current from the positive electrode active material layer 11, and a negative electrode current collector 15 that collects current from the negative electrode active material layer 12. The layer 11 is the electrode member 10. The electrode member 10 contains the electrode active material 1 and the solid electrolyte material 2.

  According to this embodiment, since the electrode member described above is used, an all-solid battery capable of reducing the interface resistance at the interface between the electrode active material and the solid electrolyte material can be obtained. Moreover, in the electrode member mentioned above, since the modifying material interdiffuses in the electrode active material and the solid electrolyte material, it exhibits excellent adhesion at the interface of the electrode active material, the modifying material, and the solid electrolyte material. It can be set as the all-solid-state battery excellent in cycling characteristics.

  In the present embodiment, there is no particular limitation as long as it contains the above-described electrode member (second-shaped electrode member), and the electrode member may be used as a positive electrode active material layer. Although it may be used as a layer, it is preferably used as a positive electrode active material layer. It is because the effect of the present invention can be exhibited more. In addition, since the other matter in the all-solid-state battery of this embodiment is the same as that of the above-mentioned “1. First embodiment”, description here is omitted.

3. Third Embodiment A third embodiment of the all solid state battery of the present invention will be described. A third embodiment includes a positive electrode active material layer containing a positive electrode active material, a negative electrode active material layer containing a negative electrode active material, and a solid electrolyte layer formed between the positive electrode active material layer and the negative electrode active material layer And using the electrode member described above, the electrode member is composed of an electrode active material layer and a solid electrolyte layer, the electrode active material layer contains an electrode active material, The solid electrolyte layer contains a solid electrolyte material.

  The all solid state battery of this embodiment was formed between the positive electrode active material layer 11, the negative electrode active material layer 12, the positive electrode active material layer 11 and the negative electrode active material layer 12, as shown in FIG. It has a solid electrolyte layer 13, a positive electrode current collector 14 that collects current from the positive electrode active material layer 11, and a negative electrode current collector 15 that collects current from the negative electrode active material layer 12. The layer 11 and the solid electrolyte layer 13 constitute the electrode member 10. The positive electrode active material layer 11 in the electrode member 10 contains a positive electrode active material (electrode active material) 1, and the solid electrolyte layer 13 contains a solid electrolyte material 2.

  According to this embodiment, since the electrode member described above is used, an all-solid battery capable of reducing the interface resistance at the interface between the electrode active material and the solid electrolyte material can be obtained. Moreover, in the electrode member mentioned above, since the modifying material interdiffuses in the electrode active material and the solid electrolyte material, it exhibits excellent adhesion at the interface of the electrode active material, the modifying material, and the solid electrolyte material. It can be set as the all-solid-state battery excellent in cycling characteristics.

  In the present embodiment, there is no particular limitation as long as at least the electrode member (third shape electrode member) described above is used, and even if the electrode active material layer in the electrode member is a positive electrode active material layer. Although it may be a negative electrode active material layer, a positive electrode active material layer is preferable. It is because the effect of the present invention can be exhibited more.

  Other configurations of the all-solid-state battery according to this embodiment are the same as those described in the section “1. First embodiment”, and thus the description thereof is omitted here.

C. Next, the manufacturing method of the electrode member of this invention is demonstrated. The electrode member manufacturing method of the present invention includes an electrode active material containing at least M ₁ element (M ₁ is a tetravalent element belonging to Group 3 to Group 15), and at least Li and M ₂ elements ( M ₂ is a different element from M ₁ and is a tetravalent element belonging to Group 3 to Group 15.), and a solid electrolyte material. the interface of the electrode active material and the solid electrolyte material, the element a (a is an element different from the above M ₁ element and the M ₂ element and a tetravalent element belonging to group 3 to group 15 group. ) a preparation step of preparing a precursor member having a modified material containing, in the precursor member heat-treated, the site of the M ₁ element of the electrode active material and the M ₂ element site of the solid electrolyte material, A heat treatment step for dissolving the element A, It is characterized in that it has.

According to the present invention, by heat-treating the electrode active material, the solid electrolyte material, and the precursor member having the modifying material, the element A contained in the modifying material becomes the M _{1 of the} electrode active material. it can be obtained an element sites, and the solid electrolyte electrode member which is a solid solution in the site of the M ₂ element materials.
Hereinafter, the manufacturing method of the electrode member of this invention is demonstrated for every process.

1. Preparation Step First, the preparation step in the present invention will be described. In the preparation step in the present invention, an electrode active material containing at least M ₁ element (M ₁ is a tetravalent element belonging to Group 3 to Group 15), and at least Li and M ₂ elements (M ₂ is A solid electrolyte material containing an element different from M ₁ and a tetravalent element belonging to Group 3 to Group 15. the interface between the material and the solid electrolyte material, a element (a is different from the above M ₁ element and the M ₂ element, a group 3 to group is a tetravalent element belonging to group 15.) containing It is a step of preparing a precursor member having a modifier.

The modified material is at least A element (the A is element other than M ₁ element and M ₂ element, and is. A tetravalent element belonging to Group 3 to Group 15 Group) long as it contains the For example, it may be the same as that described in the above section “A. Electrode member”.

  When the electrode member obtained by the present invention is, for example, in the form of particles (first shape electrode member), the amount of the solid electrolyte material in the precursor member is 1 to 20 parts by weight with respect to 100 parts by weight of the electrode active material. It is preferably in the range of parts by weight, more preferably in the range of 1 to 15 parts by weight, and particularly preferably in the range of 1 to 10 parts by weight.

Also, when the electrode member obtained by the present invention is a particulate (the first shape of the electrode member), the amount of the modified material in the precursor member, site of the M ₁ element of the electrode active material in the heat treatment step described later , And the solid electrolyte material is not particularly limited as long as it can be dissolved in the M ₂ element site, and specifically, 0.01 weight with respect to 100 parts by weight of the electrode active material. Is preferably in the range of 10 to 10 parts by weight, more preferably in the range of 0.05 to 7 parts by weight, and particularly preferably in the range of 0.05 to 5 parts by weight. preferable. By setting the blending amount of the modifier in the precursor member within the above range, the M ₁ element site of the electrode active material and the M of the solid electrolyte material in the region where the electrode active material and the solid electrolyte material are in contact with each other. _This is because it is possible to obtain an electrode member in which the element A contained in the modifier is sufficiently dissolved in the _two- element site.

2. Next, the heat treatment process in the present invention will be described. The heat treatment step in the present invention is a step in which the above-described precursor member is heat-treated, and the A element is dissolved in the M ₁ element site of the electrode active material and the M ₂ element site of the solid electrolyte material. is there.

According to this step, an electrode member in which the A element contained in the modifier is dissolved in the M ₁ element site of the electrode active material and the M ₂ element site of the solid electrolyte material is obtained. It is done.

  The heat treatment method in this step is not particularly limited as long as the element A is a method of dissolving in the electrode active material and the solid electrolyte material. The heating atmosphere in this step is not particularly limited, and examples thereof include an air atmosphere, an oxygen atmosphere, an Ar atmosphere, and a nitrogen atmosphere. In addition, the heating temperature in this step can be appropriately set according to the type of electrode active material, solid electrolyte material, and modifier used, and is preferably 550 ° C. or higher and 1100 ° C. or lower, for example. It is more preferable that the temperature is not lower than 900 ° C and not higher than 900 ° C. When the heating temperature is too lower than the above range, the heat treatment may be insufficient. On the other hand, when the heating temperature is too high than the above range, for example, lithium contained in the solid electrolyte material volatilizes, so that This is because the composition of the electrolyte material may change.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

  The present invention will be described more specifically with reference to the following examples and comparative examples.

[Example 1]
(Production of electrode member)
Prepare 0.8 g of LiNi _0.5 Mn _1.5 O ₄ (manufactured by Nichia Corporation, LNMO) as an electrode active material, 0.1 g of TiO ₂ (manufactured by Hosokawa Micron) as a modifier, and prepare a solid electrolyte As a material, 0.1 g of Li _1.5 Al _0.5 Ge _1.5 (PO ₄ ) ₃ (manufactured by Hosokawa Micron Corporation, LAGP) was prepared and mixed to obtain a precursor member. The obtained electrode member was baked in the atmosphere at 600 ° C. for 2 hours to obtain an electrode member.

[Evaluation 1]
X-ray diffraction (XRD) measurement was performed on the electrode member obtained in Example 1. The result is shown in FIG. As shown in FIG. 5, the peaks of LiNi _0.5 (Mn—Ti) _1.5 O ₄ and Li _1.5 Al _0.5 (Ge—Ti) _1.5 (PO ₄ ) ₃ were confirmed. . A TiO ₂ peak was also confirmed.

[Example 2]
(Preparation of precursor member)
LiNi _0.5 Mn _1.5 O ₄ (manufactured by Nichia Corporation, LNMO) was prepared as an electrode active material, and TiO ₂ (manufactured by Hosokawa Micron Corporation) was prepared as a modifier. The surface of LNMO was coated with TiO ₂ using a particle composite apparatus (Nobilta, manufactured by Hosokawa Micron). Thereafter, Li _1.5 Al _0.5 Ge _1.5 (PO ₄ ) ₃ (LAGP manufactured by Hosokawa Micron Corporation) was further coated as a solid electrolyte material to obtain a precursor member (composited particles before firing). The weight ratio of LNMO, TiO ₂ and LAGP was LNMO: TiO ₂ : LAGP = 100: 0.1: 5.

(Production of evaluation battery)
The obtained precursor member and LAGP (manufactured by Hosokawa Micron) were weighed so that the weight ratio was precursor member: LAGP = 100: 30, and mixed in a mortar to obtain a positive electrode mixture. Next, Nb ₂ O ₅ (manufactured by Mitsui Kinzoku Co., Ltd.) is prepared as a negative electrode active material, and Nb ₂ O ₅ and LAGP are weighed so that the weight ratio is Nb ₂ O ₅ : LAGP = 100: 30, The mixture was mixed to obtain a negative electrode mixture. Furthermore, amorphous LAGP (manufactured by Hosokawa Micron Corporation) and crystalline LAGP (manufactured by High-Purity Chemical Co., Ltd.) are prepared, and LAGP (amorphous) and LAGP (crystal) are mixed at a weight ratio of LAGP (non- Crystalline): LAGP (crystal) = 60: 40 and weighed in a mortar to obtain a solid electrolyte mixture.

  A positive electrode active material layer composed of 0.01 g of the positive electrode mixture, a solid electrolyte layer composed of 0.3 g of the solid electrolyte mixture, and a negative electrode active material layer composed of 0.01 g of the negative electrode mixture; The laminated body which has was formed. Thereafter, the laminate was pressed at a pressure of 5 MPa to form a green compact. Next, the green compact was subjected to isostatic pressing at a pressure of 196 MPa. Then, it baked on 600 degreeC and the conditions for 2 hours, and obtained the sintered compact. Au was vapor-deposited on the surface of the sintered body to form a current collector, and an evaluation battery was obtained.

[Example 3]
An evaluation battery was obtained in the same manner as in Example 2 except that the weight ratio of LNMO, TiO ₂ and LAGP in the electrode member was LNMO: TiO ₂ : LAGP = 100: 0.5: 5.

[Example 4]
An evaluation battery was obtained in the same manner as in Example 2 except that the weight ratio of LNMO, TiO ₂ and LAGP in the electrode member was LNMO: TiO ₂ : LAGP = 100: 1: 5.

[Example 5]
An evaluation battery was obtained in the same manner as in Example 2 except that the weight ratio of LNMO, TiO ₂ and LAGP in the electrode member was LNMO: TiO ₂ : LAGP = 100: 2: 5.

[Example 6]
An evaluation battery was obtained in the same manner as in Example 2 except that the weight ratio of LNMO, TiO ₂ and LAGP in the electrode member was LNMO: TiO ₂ : LAGP = 100: 3: 5.

[Comparative Example 1]
A battery for evaluation was obtained in the same manner as in Example 2 except that TiO ₂ as a modifying material was not used.

[Evaluation 2]
(Powder X-ray diffraction (XRD) measurement)
With respect to the positive electrode active material layers of the batteries for evaluation obtained in Examples 2 to 6 and Comparative Example 1, powder XRD measurement was performed, and lattice constants of LNMO and LAGP were obtained. The results are shown in Table 1.

In Example 2 to Example 6, it was confirmed that the lattice constants of LNMO, which is an electrode active material, and LAGP, which is a solid electrolyte material, change linearly with an increase in the addition amount of TiO ₂ which is a modifier. did it. From this, it was suggested that Ti contained in the modifier TiO ₂ was dissolved in LNMO and LAGP. Incidentally, FIG. 6 is an XRD measurement results for Comparative Example _1, LiNi _{0.5 Mn} 1.5 _{O 4} and _{Li 1.5 Al 0.5 Ge 1.5 (PO} 4) 3 other peak is confirmed It was done. It is considered that a resistance phase is formed from these peaks.

[Evaluation 3]
(Cyclic voltammetry (CV) measurement)
Using the evaluation batteries prepared in Examples 2 to 6 and Comparative Example 1, cyclic voltammetry measurement was performed with an insertion speed of 0.1 mV / sec and a voltage scanning range of 0 V to 4 V, and the peak current value Asked. The result is shown in FIG.

As shown in FIG. 7, the evaluation battery obtained in Example 4 showed the highest peak current value. Than this, the reason why the peak current value is increased by addition of TiO ₂ is a modified material, Mn site of an electrode active material LNMO, and LAGP Ge sites is a solid electrolyte material is contained in TiO ₂ This is probably because the formation of the resistance layer was suppressed because the Ti element was dissolved, and the interface resistance was reduced. Thus, M ₁ element site of the electrode active material, and the M ₂ element site of the solid electrolyte material, A element contained in the modified material by solid solution, can be reduced interfacial resistance was confirmed.

DESCRIPTION OF SYMBOLS 1 ... Electrode active material 2 ... Solid electrolyte material 3 ... Modifier 4 ... Area | region where an electrode active material and solid electrolyte material contact | connect 10 ... Electrode member 11 ... Positive electrode active material layer 12 ... Negative electrode active material layer 13 ... Solid electrolyte layer 14 ... Positive electrode Current collector 15 ... Negative electrode current collector 20 ... All-solid-state battery

Claims (10)

(The _{M 1} is a tetravalent element belonging to Group 3 to Group 15 Group.) At least _{M 1} element and the electrode active material containing, at least Li and _{M 2} element _{(M 2} with different elements as the _{M 1} And a solid electrolyte material containing a tetravalent element belonging to Group 3 to Group 15),
In the electrode active material and the solid region electrolyte material is in contact, wherein M ₁ element site of the electrode active material, and the M ₂ element site of the solid electrolyte material, A element (A is the M ₁ element and wherein an element other than M ₂ element is a tetravalent element belonging to group 3 to group 15 group.) electrode member, characterized in that a solid solution is. If the ion radius of the element A and _{R A,} the ion radius of the _{M 1} element and _{R M1,} the ionic radius of the _{M 2} element and a _{R M2,}
2. The value obtained by dividing the absolute value of (R _A −R _M1 ) by R _A and the value obtained by dividing the absolute value of (R _A −R _M2 ) by R _A are 20% or less. An electrode member according to 1.   3. The electrode member according to claim 1, further comprising a modifier containing the element A at an interface between the electrode active material and the solid electrolyte material.   The electrode member according to any one of claims 1 to 3, wherein the electrode member is in the form of particles.   The electrode member according to any one of claims 1 to 3, wherein the electrode member is an electrode active material layer containing the electrode active material and the solid electrolyte material. Consists of an electrode active material layer and a solid electrolyte layer,
The electrode active material layer contains the electrode active material;
The electrode member according to any one of claims 1 to 3, wherein the solid electrolyte layer contains the solid electrolyte material. An all solid having a positive electrode active material layer containing a positive electrode active material, a negative electrode active material layer containing a negative electrode active material, and a solid electrolyte layer formed between the positive electrode active material layer and the negative electrode active material layer A battery,
An all-solid-state battery using the electrode member according to any one of claims 1 to 6. (The _{M 1} is a tetravalent element belonging to Group 3 to Group 15 Group.) At least _{M 1} element and the electrode active material containing, at least Li and _{M 2} element _{(M 2} with different elements as the _{M 1} And a solid electrolyte material containing a tetravalent element belonging to Group 3 to Group 15.),
The interface between the electrode active material and the solid electrolyte material, A element (A is an element other than the M ₁ element and the M ₂ element is a tetravalent element belonging to Group 3 to Group 15 Group. And a preparatory step of preparing a precursor member having a modifier containing
The precursor member heat-treated, the site of the M ₁ element of the electrode active material, and the M ₂ element site of the solid electrolyte material, and a heat treatment step of solid solution of the element A,
A method for producing an electrode member, comprising:   The method for manufacturing an electrode member according to claim 8, wherein the modifier is an oxide. The method for manufacturing an electrode member according to claim 8 or 9, wherein the modifying material is TiO ₂ .

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