JP2017084515A - Negative electrode layer, and all-solid-state lithium ion secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a negative electrode layer increasing battery capacity and output density of an all-solid-state lithium ion secondary battery, and an all-solid-state lithium ion secondary battery including the negative electrode layer.SOLUTION: A negative electrode layer 30 of the present invention is a negative electrode layer in an all-solid-state lithium ion secondary battery, and includes an electron conductive porous body 31 having a plurality of voids 32, and lithium metal 33 deposited on the surfaces of the plurality of voids 32.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a negative electrode layer and an all solid lithium ion secondary battery including the negative electrode layer.

  2. Description of the Related Art Conventionally, all-solid-state secondary batteries that can be charged and discharged and have a relatively large battery capacity have been used as power sources for portable information terminals such as smartphones and notebook personal computers.

  It has been known that such an all-solid secondary battery improves the electron conductivity and increases the output density by increasing the area of the electrode layer (positive electrode layer or negative electrode layer).

For example, Patent Document 1 discloses an all-solid-state secondary battery that is a laminated body in which a positive electrode layer, a solid electrolyte layer, and a negative electrode layer are laminated in this order and sintered. At least one of the positive electrode layer or the negative electrode layer includes an electrode active material and a conductive agent including a carbon material, and the conductive agent includes a carbon material having a specific surface ratio of 1000 m ² / g or less.

  By using such a carbon material as a conductive agent, combustion of the carbon material can be suppressed in the firing step of removing an organic material such as a binder, so that the proportion of the carbon material remaining in the electrode layer can be increased. it can.

  Thus, an all-solid secondary battery in which the electron conductivity is improved while the electrode layer and the solid electrolyte layer are sintered and joined is disclosed.

International Publication No. 2011/132627

  However, in the all-solid-state secondary battery described in Patent Document 1, a metal layer of an active material is provided between the negative electrode layer and the solid electrolyte layer to enhance conductivity such as lithium ions.

  Therefore, when this metal layer is formed on a negative electrode layer made porous by sintering, for example, by a vapor phase growth method such as a vacuum evaporation method, the metal layer is formed only on the surface of the negative electrode layer. It is difficult to form a metal layer up to the voids inside the layer.

  As a result, the ratio of the area of the metal layer to the negative electrode layer is limited, the capacity density of the active material in the negative electrode layer does not substantially improve, and the output density of the all-solid-state secondary battery cannot be sufficiently secured. there were.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  [Application Example 1] The negative electrode layer described in this application example is a negative electrode layer of an all-solid-state lithium ion secondary battery, and is formed on an electron conductive porous body having a plurality of voids and on the surfaces of the plurality of voids. And deposited lithium metal.

  According to this application example, the area where the porous body and the lithium metal are in contact with each other can be increased. As a result, it is possible to provide a negative electrode layer capable of increasing the battery capacity and output density of the all solid lithium ion secondary battery.

  Application Example 2 In the negative electrode layer described in the application example, it is preferable that the plurality of voids include continuous voids.

  According to this configuration, lithium metal can be deposited more easily in the communicating voids, and when used as the negative electrode of a lithium secondary battery, a battery having a higher capacity can be obtained.

  Application Example 3 In the negative electrode layer described in the application example, it is preferable that the lithium metal is deposited over the entire region of the surface of the plurality of voids.

  According to this configuration, the contact area between the porous body and the lithium metal is increased as compared with the case where the lithium metal is provided on a part of the surface of the void. Therefore, good charge transfer is possible at the interface between the porous body and the lithium metal, and the interface resistance can be reduced.

  Application Example 4 In the negative electrode layer described in the application example, it is preferable that a conductive film having an electron conductivity higher than that of the porous body is provided on the surface of the plurality of voids.

  According to this configuration, it becomes easy to transfer electrons on the surface of the gap.

  Application Example 5 In the negative electrode layer described in the application example, the conductive film is preferably a metal thin film.

  According to this configuration, the electronic conductivity of the conductive film can be increased as compared with the non-metallic conductive film. Therefore, the resistance of the negative electrode layer can be reduced.

  Application Example 6 In the negative electrode layer according to the application example described above, it is preferable that the lithium metal film is thicker than or equal to the film thickness of the conductive film.

  According to this configuration, the lithium capacity in the negative electrode layer can be increased compared to the case where the thickness of the lithium metal film is smaller than that of the conductive film, and the reaction of the negative electrode layer due to charge / discharge can be efficiently advanced. It is done.

  [Application Example 7] The all-solid-state lithium ion secondary battery described in this application example includes the negative electrode layer described in the above application example.

  According to this application example, the area where the porous body and the lithium metal are in contact with each other can be increased. As a result, the battery capacity and output density of the all solid lithium ion secondary battery can be increased.

  In addition, since the lithium secondary battery is configured using a negative electrode layer on which lithium metal is pre-deposited, the battery is prevented from being damaged due to lithium metal volume fluctuations associated with charge / discharge, and the all-solid-state lithium ion secondary battery has a long service life. Can be.

The schematic perspective view which shows the structure of the lithium battery which concerns on 1st Embodiment. The schematic cross section which shows the structure of a negative electrode layer. The schematic cross section which shows the structure of a negative electrode layer. Process drawing which shows the process of forming a separator precursor. Process drawing which shows the process of forming a positive electrode layer precursor. Process drawing which shows the process of forming a cell. Process drawing which shows the process of forming an electrical power collector. Process drawing which shows the process of depositing lithium metal. The schematic cross section which shows the structure of the negative electrode layer which concerns on 2nd Embodiment. The schematic cross section which simplified and showed the manufacturing method of the negative electrode layer which concerns on 3rd Embodiment. The schematic cross section which simplified and showed the manufacturing method of the negative electrode layer which concerns on 3rd Embodiment. The schematic cross section which simplified and showed the manufacturing method of the negative electrode layer which concerns on 3rd Embodiment. The schematic cross section which simplified and showed the manufacturing method of the negative electrode layer which concerns on 3rd Embodiment.

  DESCRIPTION OF EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings. In the following figures, the scale of each component is described on a scale different from the actual scale so that each component can be recognized on the drawing for easy understanding. There is.

[First Embodiment]
<Configuration of all-solid-state lithium ion secondary battery>
A configuration of an all solid lithium ion secondary battery (hereinafter simply referred to as a lithium battery) of the present embodiment will be described with reference to FIG. Lithium batteries can be charged and discharged and can provide a large output energy, and thus can be suitably used as a power source for portable information terminals such as smartphones.

  FIG. 1 is a schematic perspective view showing the configuration of the lithium battery according to the first embodiment. As shown in FIG. 1, the lithium battery 100 of this embodiment includes a positive electrode layer 10, a separator 20, and a negative electrode layer 30. The positive electrode layer 10, the separator 20, and the negative electrode layer 30 are referred to as a cell 40.

  In addition, the lithium battery 100 includes a current collector 41 provided on a surface opposite to the surface in contact with the separator 20 of the positive electrode layer 10 and a current collector provided on a surface on the opposite side to the surface in contact with the separator 20 of the negative electrode layer 30. Electric body 42. That is, the lithium battery 100 is a stacked body in which the current collector 41, the positive electrode layer 10, the separator 20, the negative electrode layer 30, and the current collector 42 are stacked in this order.

  The lithium battery 100 of the present embodiment is formed in a disc shape, and the outer size is, for example, φ10 mm, and the thickness is, for example, 0.08 mm. The shape of the lithium battery 100 is not limited to a disk shape, and may be a polygonal disk shape, for example.

(Positive electrode layer)
The positive electrode layer 10 includes an active material part including a transition metal oxide, and a solid electrolyte part including the ion conductive solid in contact with the active material part, so that the active material part and the solid electrolyte part are in contact with each other. Is formed.

Preferable examples of the active material part include compounds having a layered crystal structure belonging to the space group R3m among transition metal oxides such as LiCoO ₂ and LiNiO ₂ . The transition metal oxide may contain transition metals such as Mn, Cu, Zr, La, and Ce, and metals such as Al and Er, in addition to Co and Ni.

  The solid electrolyte portion includes an ion conductive solid, that is, an ion conductive solid electrolyte, and examples of the ion conductive solid electrolyte include materials shown in the separator 20 described later.

(separator)
The separator 20 is provided between the positive electrode layer 10 and the negative electrode layer 30, and is a solid electrolyte layer that mediates lithium ion conduction while maintaining electrical insulation between these electrode layers.

The solid electrolyte having ion _{conductivity, Li 6.75 La 3 Zr 1.75 Nb} 0.25 O 12, SiO 2 -SiO 2 -P 2 O 5 -Li 2 O, SiO 2 -P 2 O 5 -LiCl, Li 2 O- LiCl—B ₂ O ₃ , Li _3.4 V _0.6 Si _0.4 O ₄ , Li ₁₄ ZnGe ₄ O ₁₆ , Li _3.6 V _0.4 Ge _0.6 O ₄ , Li _1.3 Ti _1.7 Al _0.3 (PO ₄ ) ₃ , Li _2.88 PO _3.73 N _0.14 LiNbO ₃ , Li _0.35 La _0.55 TiO ₃ , Li ₂ S—SiS ₂ , Li ₂ S—SiS ₂ —LiI, Li ₂ S—SiS ₂ —P ₂ S ₅ , Li ₃ N, LiI, LiI—CaI ₂ , _{LiI-CaO, LiAlCl 4, LiAlF} 4, LiI-Al 2 O 3, LiF-Al 2 O 3, LiBr-Al 2 O 3, Li 2 O-TiO 2, La 2 O 3 -Li 2 O-TiO 2, _{Li 3 NI 2, Li 3 N} -LiI-LiOH _{Li 3 N-LiCl, Li 6} NBr 3, LiSO 4, Li 4 SiO 4, Li 3 PO 4 -Li 4 SiO 4, Li 4 GeO 4 -Li 3 VO 4, Li 4 SiO 4 -Li 3 VO 4, Li _{4 GeO 4 -Zn 2 GeO 2,} Li 4 SiO 4 -LiMoO 4, Li 3 PO 4 -Li 4 SiO 4, Li 4 SiO 4 -Li 3 ZrO 4, LiBH 4, Li 7-x PS 6-x Cl x Any of crystalline, amorphous, and partially crystallized glass of oxides, sulfides, nitrides, hydrogenations, or partially substituted products thereof, such as Li ₁₀ GeP ₂ S _12, is preferably used.

Moreover, two or more kinds of solid electrolytes as described above can be included. If necessary, a solid electrolyte in which fine particles of an insulator such as Al ₂ O ₃ , SiO ₂ , and ZrO ₂ are combined can also be used.

  The thickness of the separator 20 is preferably about 50 nm to 100 μm, but can be set to a desired value depending on material characteristics and design. In addition, an uneven structure such as a trench, a grating, or a pillar can be provided on the surface of the separator 20 on the negative electrode layer 30 side by combining various molding methods and processing methods.

  The separator 20 may have a multilayered structure, for example, a glass electrolyte layer is formed on the surface of a layer formed of a crystalline material, for example, for the purpose of preventing a short circuit, as well as a single layer.

(Current collector)
As the current collectors 41 and 42, any material can be suitably used as long as it does not cause an electrochemical reaction with the positive electrode layer 10 or the negative electrode layer 30 and has electron conductivity.

  As an example of the current collectors 41 and 42, one metal selected from the group consisting of Cu, Mg, Ti, Fe, Co, Ni, Zn, Al, Ge, In, Au, Pt, Ag, and Pd (metal Simple substance), alloys containing two or more metal elements selected from this group, conductive metal oxides such as ITO, ATO, and FTO, and metal nitrides such as TiN, ZrN, and TaN.

  The current collectors 41 and 42 are suitable for the user according to the purpose, such as a thin film of the above-mentioned material having electron conductivity, a metal foil, a plate, or a paste obtained by kneading fine conductive powder together with a binder. Can be selected.

(Negative electrode layer)
Next, the negative electrode layer 30 of this embodiment is demonstrated with reference to FIG. 2 and FIG. 2 and 3 are schematic cross-sectional views showing the configuration of the negative electrode layer. Specifically, FIG. 2 is a schematic cross-sectional view along a direction orthogonal to the thickness direction of the negative electrode layer, and FIG. 3 is a schematic cross-sectional view along the thickness direction of the negative electrode layer.

  As shown in FIG. 2, the negative electrode layer 30 includes a porous body 31, voids 32, and lithium metal 33. The thickness of the negative electrode layer 30 is preferably 50 nm to 100 μm, but can be arbitrarily designed according to desired battery capacity and material characteristics.

  The porous body 31 may be one in which the forming material constituting the porous body 31 has electron conductivity, or when the forming material constituting the porous body 31 is poor in electron conductivity, It may be composited to provide desired electronic conductivity.

  As an example in which the porous body 31 is composed of a material having electron conductivity, a metal or electron-conductive non-metal processed into a mesh shape, a fiber shape, or a sponge shape can be cited.

Specifically, a silicon-manganese alloy (Si-Mn), a silicon-cobalt alloy (Si-Co), a silicon-nickel alloy (Si-Ni), niobium pentoxide (Nb ₂ O ₅ ), vanadium pentoxide (V ₂ O ₅ ), titanium oxide (TiO ₂ ), indium oxide (In ₂ O ₃ ), zinc oxide (ZnO), tin oxide (SnO ₂ ), nickel oxide (NiO) and the like.

  In addition, as an example in which the forming material constituting the porous body 31 is combined with an electron conductive substance to give desired electron conductivity, an ion conductive oxide, sulfide, polymer, or the like is meshed, What processed into desired shapes, such as fibrous form and sponge form, is mentioned.

Specifically, indium oxide (ITO) to which tin (Sn) is added, zinc oxide (AZO) to which aluminum (Al) is added, zinc oxide (GZO) to which gallium (Ga) is added, antimony (Sb) ) Added tin oxide (ATO), fluorine (F) added tin oxide (FTO), carbon materials, substances in which lithium ions are inserted between carbon materials (LiC ₂₄ , LiC ₆ etc.), TiO ₂ anatase phase, lithium double oxides such as Li ₄ Ti ₅ O 1 ₂ and Li ₂ Ti ₃ O ₇ , Li metal and the like.

  The porous body 31 of the present embodiment is obtained by mixing 10 parts by weight of, for example, polyvinylidene fluoride (PVdF), which is a binder, with 90 parts by weight of activated carbon which is an electron conductive material, and pressurizing and sintering. It is formed by molding.

The void 32 is a plurality of pores arranged inside the porous body 31. The bulk density porosity in the gap 32 can be obtained by the following equation (1).

  The bulk density porosity in the gap 32 is preferably 10% or more and 50% or less. If the bulk density porosity is less than 10%, it is difficult to achieve a high capacity density, and if it exceeds 50%, the ratio of the voids 32 to the porous body 31 may be too large and become brittle. In other words, the particle size distribution of the electron conductive material and the proportion of the binder are adjusted and the pressure and sintering conditions are adjusted so that the bulk density porosity is 10% or more and 50% or less.

  As shown in FIG. 3, the plurality of voids 32 formed in this manner include portions that communicate with each other in a mesh shape inside the porous body 31. In addition, the space | gap 32 will be in the state connected not only to the surface layer of the porous body 31, but to the deep part. FIG. 3 schematically shows the state of the communicating air gap 32. The communicating air gap 32 does not necessarily have a fixed shape, and the size of the air gap 32 is random.

  Therefore, even if an active material having an electrochemical anisotropy is used as the active material, the communicating void 32 is formed electrochemically regardless of the anisotropy of the electron conductivity or ionic conductivity of the crystal. It forms a smooth continuous surface. As a result, the negative electrode layer 30 having good electronic conductivity can be provided regardless of the type of active material used.

  The lithium metal 33 is provided over the entire area of the surface of each void 32 inside the porous body 31, and when the lithium battery 100 is charged, the potential of the negative electrode layer 30 is made equal to or lower than the reduction potential of lithium ions. It is deposited by maintaining. The lithium metal 33 is preferably deposited over the entire area of the surface of each void 32, but the negative electrode layer 30 has a void 32 in which the lithium metal 33 is deposited on a part of the surface of each void 32. May be included.

  Since the porous body 31 and the lithium metal 33 are in contact with each other on the surface of the gap 32, a state in which the electric capacity density is high is realized.

<Lithium battery manufacturing method>
Next, the manufacturing method of the lithium battery of this embodiment is demonstrated with reference to FIGS. FIG. 4 is a process diagram showing a process of forming a separator precursor, FIG. 5 is a process chart showing a process of forming a positive electrode layer precursor, and FIG. 6 is a process chart showing a process of forming a cell. FIG. 7 is a process diagram showing a process of forming a current collector, and FIG. 8 is a process chart showing a process of depositing lithium metal.

  The manufacturing method of the lithium battery of this embodiment includes a step of forming the separator precursor 20a (step S1), a step of forming the positive electrode layer precursor 10a (step S2), and a step of forming the cell 40 (step S3). And a step of forming current collectors 41 and 42 (step S4) and a step of depositing lithium metal 33 (step S5).

(1) Step S1 Step of Forming Separator Precursor As shown in FIG. 4, a slurry of Li _2.2 C _0.8 B _0.2 O ₃ processed into powder is applied to the surface 30S of the negative electrode layer 30, and the separator precursor 20a Form.

(2) Step S2 Step of Forming Positive Electrode Layer Precursor As shown in FIG. 5, in order to form a structure in which the negative electrode layer 30 is connected to the positive electrode active material via the separator 20, LiCoO is used as the positive electrode active material. A mixture of 85 parts by weight, 10 parts by weight, and 5 parts by weight of a mixture of ₂ and PVdF and acetylene black is applied to the separator precursor 20a and laminated to form the positive electrode layer precursor 10a.

(3) Step S3 Step of Forming Cell As shown in FIG. 6, a laminate in which the separator precursor 20a and the positive electrode layer precursor 10a are laminated on the negative electrode layer 30 in an inert atmosphere at 700 ° C. for 5 minutes. And heat treatment (sintering). As a result, the cell 40 in which the negative electrode layer 30 and the positive electrode layer 10 are connected via the separator 20 is formed.

(4) Step S4 Current Collector Forming Step As shown in FIG. 7, the current collector is formed by depositing Pt (platinum) on each surface of the positive electrode layer 10 and the negative electrode layer 30 so as to have a film thickness of about 120 nm. 41 and 42 are formed. Thereby, the collectors 41 and 42 and the cell 40 are reliably joined.

  The current collector can be formed by separately providing an appropriate adhesive layer for adhesion, as well as vapor deposition methods such as vacuum deposition, CVD, PLD, ALD, and aerosol deposition, sol-gel, and organometallic heat. An appropriate method can be used according to the reactivity with the current collector forming surface, the electrical conductivity desired for the electric circuit, and the electric circuit design, such as a decomposition method and a wet method such as plating.

  The current collectors 41 and 42 are formed as necessary. For example, in the case where an electrode layer is combined on a conductive substrate, the current collectors 41 and 42 are necessarily formed on both the positive electrode layer 10 and the negative electrode layer 30. There is no.

  The current collectors 41 and 42 may be formed after the stacked body of the positive electrode layer 10, the separator 20, and the negative electrode layer 30 is formed or before the stacked body is formed.

(5) Step S5 Step of depositing lithium metal As shown in FIG. 8, the potential of the negative electrode layer 30 of the cell 40 obtained as described above is maintained at the reduction potential of lithium ions. By overcharging the negative electrode layer 30 with a potential of 0 V and a potential of 4.2 V, the lithium ions move from the positive electrode layer 10 side to the negative electrode layer 30 side, and on the surfaces of the respective voids 32 of the negative electrode layer 30. Lithium metal 33 is deposited. At this time, the film thickness of the lithium metal 33 is controlled by controlling the energization time based on Nernst's law.

  In this way, the lithium battery 100 having the negative electrode layer 30 in which the lithium metal 33 is deposited on the surface of the void 32 in the electron conductive porous body 31 already shown in FIG. 1 is obtained. From the above, according to the present embodiment, the following effects can be obtained.

  (1) Since the negative electrode layer 30 of the present embodiment includes the lithium metal 33 on the surfaces of the plurality of voids 32 inside the porous body 31, the area where the porous body 31 and the lithium metal 33 are in contact with each other is increased. can do. As a result, the negative electrode layer 30 capable of increasing the battery capacity and output density of the lithium battery 100 can be provided.

  (2) In the communicating void 32, the lithium metal 33 can be deposited more easily, and when used as a negative electrode of a lithium secondary battery, a battery having a higher capacity can be obtained.

  (3) Since the lithium metal 33 is deposited over the entire region of the surface of the plurality of voids 32, compared to the case where the lithium metal 33 is provided on a part of the surface of the void 32, The contact area between the porous body 31 and the lithium metal 33 is increased. Therefore, good charge transfer is possible at the interface between the porous body 31 and the lithium metal 33, and the interface resistance can be reduced.

  (4) Since the lithium battery 100 of this embodiment includes the negative electrode layer 30 described above, the area where the porous body 31 and the lithium metal 33 are in contact with each other can be increased. As a result, the battery capacity and output density of the lithium battery 100 can be increased. Moreover, since the porous body 31 has a plurality of voids 32, the battery can be prevented from being damaged due to the volume fluctuation of the lithium metal 33 due to charge / discharge, and the lithium battery 100 can have a long life.

[Second Embodiment]
<Configuration of negative electrode layer>
Next, the negative electrode layer of 2nd Embodiment is demonstrated with reference to FIG. In addition, about a common part with the said 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted and it demonstrates centering on a different part from the said 1st Embodiment.

  FIG. 9 is a schematic cross-sectional view showing the configuration of the negative electrode layer according to the second embodiment. Specifically, FIG. 9 is a schematic cross-sectional view along a direction orthogonal to the thickness direction of the negative electrode layer 130. As shown in FIG. 9, the negative electrode layer 130 according to this embodiment is different from the negative electrode layer 30 of the first embodiment in that a conductive film 34 is provided on the surface of the void 32 inside the porous body 31. ing.

  The negative electrode layer 130 according to the present embodiment includes a porous body 31, voids 32, lithium metal 33, and a conductive film 34. The lithium metal 33 is deposited on the surface of the conductive film 34 that covers the surface of the gap 32.

  The conductive film 34 is provided on the surface of each gap 32 and has an electron conductivity higher than that of the porous body 31. Examples of such a conductive film 34 include platinum (Pt) and an alloy of platinum (Pt) and gold (Au).

  Further, as a method of forming the conductive film 34, it is preferable to use an electrolytic plating method or an electroless plating method in order to form a film uniformly on the surface of the gap 32. The film thickness of the conductive film 34 is, for example, about 50 nm to 3 μm.

  Since the conductive layer 34 is provided between the negative electrode layer 130 and the lithium metal 33 on the surface of the gap 32, electrons are easily transferred, and the surface of the gap 32 is charged when the lithium battery 100 is charged. Lithium metal 33 is easily deposited on the surface.

  Moreover, since the conductive film 34 is a metal thin film, the resistance of the porous body 31 having electron conductivity, that is, the negative electrode layer 130 can be reduced.

  From the viewpoint of improving the battery capacity and output density of the all-solid lithium secondary battery using the negative electrode layer 130, the lithium metal 33 is preferably thicker than the conductive film 34. Note that the film thickness of the lithium metal 33 may be substantially the same as the film thickness of the conductive film 34.

[Third Embodiment]
<Method for producing negative electrode layer>
This embodiment shows an example of forming a negative electrode layer as one of the constituent elements of a lithium battery. The negative electrode layer may be formed using the porous body 31 shown in the first embodiment, or may be formed using the porous body 31 including the conductive film 34 shown in the second embodiment. In the present embodiment, for the sake of convenience, description will be made using the porous body 31.

  FIG. 10A to FIG. 10D are schematic cross-sectional views schematically showing the method for manufacturing the negative electrode layer according to this embodiment. Although described above using the porous body 31 in the present embodiment, it may be formed using the porous body 31 including the conductive film 34.

  FIG. 10A shows a porous body 31 to which a production collecting electrode 50 is connected. The production collecting electrode 50 is temporarily fixed to the porous body 31 with a conductive adhesive or the like (not shown) that can be peeled off. As shown in FIG. 10B, the porous body 31 to which the production collecting electrode 50 is connected is installed in a production container 54 having an electrolyte solution 51 and an active material 52 containing Li.

  For the active material 52, for example, a material containing lithium cobalt oxide can be used. The production container 54 has a separator 55 inside, and has a structure in which the deposited lithium metal prevents a short circuit between the porous body 31 and the active material 52. The electrolyte solution 51 permeates the separator 55, and lithium ions can pass through the separator 55. The manufacturing container 54 has a collector electrode 56 electrically connected to the active material 52 at the bottom.

  Next, as shown in FIG. 10C, an appropriate voltage determined by the active material 52 is applied between the production collecting electrode 50 and the collecting electrode 56, whereby the electrode in each of the porous body 31 and the active material 52. By causing the reaction, lithium ions from the active material 52 are deposited as the lithium metal 33 on the porous body 31 through the electrolyte solution 51.

  Next, as shown in FIG. 10D, the porous body 31 to which the manufacturing collector electrode 50 is connected is taken out from the manufacturing container 54, and the manufacturing collector electrode 50 is peeled off from the porous body 31, whereby the lithium metal 33 is removed. The deposited porous body 31, that is, the negative electrode layer 30 requiring the cross-sectional view shown in FIG. 2 can be obtained.

  The negative electrode layer 30 thus formed can be used not only for a lithium battery but also as a general-purpose component, and can be distributed as a single component.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification. All-solid lithium ion secondary batteries to which the negative electrode layer is applied are also included in the technical scope of the present invention. Various modifications other than the above embodiment are conceivable. Hereinafter, a modification will be described.

[Modification]
As a method for precipitating the lithium metal 33 on the surface of the void 32, lithium hydride and alkylated lithium (methyl lithium, n-butyl lithium, etc.) are dissolved or suspended in a solvent such as toluene, hexane, etc. Lithium metal 33 is obtained by impregnating the electric conductor of the body 31 and then drying the solvent to deposit the solute in the gap 32 and reducing and firing at 400 ° C. to 700 ° C. in a reducing atmosphere such as an argon gas atmosphere. May be deposited.

  DESCRIPTION OF SYMBOLS 10 ... Positive electrode layer, 10a ... Positive electrode layer precursor, 20 ... Separator, 20a ... Separator precursor, 30 ... Negative electrode layer, 31 ... Porous body, 32 ... Void, 33 ... Lithium metal, 34 ... Conductive film, 40 ... Cell , 41 ... current collector, 42 ... current collector, 100 ... lithium battery as an all solid lithium ion secondary battery, 130 ... negative electrode layer.

Claims (7)

A negative electrode layer of an all-solid-state lithium ion secondary battery,
An electron conductive porous body having a plurality of voids;
And a lithium metal deposited on the surfaces of the plurality of voids.   The negative electrode layer according to claim 1, wherein the plurality of voids include a void that is in communication.   The negative electrode layer according to claim 1, wherein the lithium metal is deposited over the entire region of the surface of the plurality of voids.   4. The conductive film having an electronic conductivity higher than that of the porous body is provided on a surface of the plurality of voids. 5. Negative electrode layer.   The negative electrode layer according to claim 4, wherein the conductive film is a metal thin film.   6. The negative electrode layer according to claim 4, wherein a film thickness of the lithium metal is greater than or equal to a film thickness of the conductive film.   An all-solid-state lithium ion secondary battery comprising the negative electrode layer according to any one of claims 1 to 6.

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