JP5900281B2 - All-solid battery and method for manufacturing the same - Google Patents

Description

  The present invention relates to an all-solid-state battery and a method for manufacturing the same, and more particularly, to an all-solid-state battery that can suppress both a decrease in capacity of the battery and propagation when separation occurs between an active material and a solid electrolyte. Regarding the method.

In recent years, lithium batteries have been put into practical use as batteries having high voltage and high energy density. Due to the expansion of the use of lithium batteries in a wide range of fields and the demand for high performance, various studies have been conducted to further improve the performance of lithium batteries.
Among them, since the electrolyte is not used compared to the conventional non-aqueous electrolyte lithium battery, the system required for improving the safety when using the non-aqueous electrolyte can be simplified. Therefore, it is expected that the all-solid-state battery will be put to practical use because it can have many advantages such as an increased degree of freedom and a reduced number of auxiliary devices.

However, in order to realize the practical application of all-solid-state batteries, various improvements such as the creation of a solid electrolyte capable of providing high capacity and high output and / or the creation of electrodes capable of realizing high electrode utilization efficiency are required. It is.
In particular, the all-solid-state battery may be separated from the solid electrolyte and the active material due to expansion and contraction associated with charging / discharging of the active material, and the characteristics (capacity) may be reduced by the charge / discharge cycle. For example, when the active material and the solid electrolyte are in full contact, the capacity drops rapidly because peeling or cracking occurs somewhere or if twisting is applied, the peeling may propagate or break. Can do. For this reason, attempts have been made to prevent peeling between the active material layer and the solid electrolyte layer, propagation of cracks, or damage when the battery is twisted.

  For example, Patent Document 1 discloses a sheet battery in which a plurality of solid power generation cells each including a power generation element in which a positive electrode active material, a solid electrolyte, and a negative electrode active material are layered on a sheet having bending properties are arranged in a grid pattern. Have been described.

  Further, in Patent Document 2, a battery element in which a positive electrode made of an inorganic compound, a solid electrolyte, and a negative electrode are sequentially stacked is provided on a current collector, and a plurality of battery elements are arranged at intervals of 0.1 to 5000 μm. An all-solid-state secondary battery and a method for manufacturing the all-solid-state secondary battery in which the battery element is cut into a plurality of parts by chemical etching, dicing, or the like are described. As a specific example, a plurality of battery elements are integrated and arranged on a current collector An example is shown in which an all-solid secondary battery is obtained by hot pressing later or processing a large battery element with a laser leaving a current collector.

  Patent Document 3 discloses a battery assembly including a flexible substrate and a plurality of assemblies each including a single cell including a positive electrode, a solid electrolyte, and a negative electrode arranged on the substrate. There is described an assembled battery in which the outer periphery is rectangular and the rectangular aggregate is divided into four single cells by strip-shaped plain portions provided on two diagonal lines of the rectangle.

JP 2000-195482 A JP 2001-015153 A JP 2004-303715 A

However, when these known techniques are applied, the active material layer is divided, so that the amount of the active material of the all-solid battery is reduced, or some active materials are deteriorated because each battery is shut off. However, Li ions cannot be supplied from the surrounding active material, and it is difficult to suppress the capacity reduction of the battery, and the cycle characteristics of the all-solid battery are poor.
Accordingly, an object of the present invention is to provide an all solid state battery that can suppress both a decrease in capacity of the battery and propagation when separation occurs between an active material and a solid electrolyte.
Another object of the present invention is to provide a method for producing an all-solid-state battery that can suppress both a decrease in capacity of the battery and propagation when separation occurs between the active material and the solid electrolyte. .

The present invention is an all-solid battery having a solid electrolyte layer sandwiched between a positive electrode active material layer and a negative electrode active material layer, wherein both the active material layers are continuous, and the solid electrolyte layer is the positive electrode active material It is divided in the multiple by layers and the negative electrode active material layers in the through-hole, to the battery.

The present invention also provides a method for producing an all-solid battery,
A step of providing a mesh-like masking on one continuous active material layer of either the positive electrode active material layer or the negative electrode active material layer;
A step of forming a solid electrolyte layer by sputtering a solid electrolyte on one of the active material layers provided with the masking;
It is related with the said method including the process of removing the masking and forming the solid electrolyte layer divided | segmented into plurality, and the process of affixing the other active material layer continuous on the said solid electrolyte layer.

ADVANTAGE OF THE INVENTION According to this invention, the all-solid-state battery which can suppress both the capacity | capacitance fall of a battery and the propagation | transmission at the time of peeling between an active material and a solid electrolyte can be obtained.
In addition, according to the present invention, it is possible to easily obtain an all-solid-state battery that can suppress both the battery capacity reduction and the propagation when peeling occurs between the active material and the solid electrolyte.

FIG. 1 is a partial side view schematically showing an all solid state battery according to an embodiment of the present invention. FIG. 2 is a partial side view schematically showing an all-solid battery outside the scope of the present invention. FIG. 3 is a partial side view schematically showing an all solid state battery outside the scope of the present invention. FIG. 4 is a schematic diagram showing the steps of an embodiment of the method for producing an all solid state battery of the present invention. FIG. 5 is a schematic diagram showing the steps of a method for producing an all-solid battery outside the scope of the present invention.

In particular, in the present invention, the following embodiments can be mentioned.
1) The all solid state battery, wherein the solid electrolyte is an oxide solid electrolyte.
2) The all-solid battery, wherein the solid electrolyte is lithium phosphate (Li ₃ PO ₄ ) or lithium phosphate oxynitride (LiPON) in which a part of oxygen of the lithium phosphate is replaced with nitrogen.
3) The all solid state battery, wherein the positive electrode active material layer is made of a metal oxide containing at least one transition metal selected from manganese, cobalt, nickel and titanium and lithium.
4) The all solid state battery in which the negative electrode active material layer is made of lithium metal (Li) or an alloy of lithium and titanium, magnesium, or aluminum.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1, an all solid state battery 1 according to an embodiment of the present invention has an all solid state battery having a solid electrolyte layer 4 sandwiched between a positive electrode active material layer 2 and a negative electrode active material layer 3 on a current collector foil 5. The both active material layers 2 and 3 are continuous, and the solid electrolyte layer 4 has a plurality of through holes 6 in the positive electrode active material layer 2 and the negative electrode active material layer 3. .

According to the all solid state battery of the embodiment of the present invention, the solid electrolyte layer is divided into a plurality of parts between the positive electrode active material layer and the negative electrode active material layer, so that the solid electrolyte layer is divided as shown in FIG. As compared with the all solid state battery 10 outside the scope of the present invention, deterioration of cycle characteristics is suppressed.
The effect of suppressing the deterioration of the cycle characteristics is particularly remarkable in an all-solid battery using an oxide solid electrolyte as a solid electrolyte.

  This is because, in the conventionally known all solid state battery 10 that does not have the above-described through-holes, peeling due to expansion and contraction of the active material layer between the positive electrode active material layer 2 and / or the negative electrode active material layer 3 and the solid electrolyte layer 4 occurs. Although it propagates, in the all solid state battery of the embodiment of the present invention, it is considered that separation between the active material and the solid electrolyte does not propagate due to the separation of the solid electrolyte, thereby suppressing an increase in internal resistance. It is done.

  Furthermore, as shown in FIG. 3, the all-solid battery 11 outside the scope of the present invention includes a battery in which a positive electrode active material layer 2, a solid electrolyte layer 4, and a negative electrode active material layer 3 are sequentially stacked. A plurality of battery units 12 and 13 are arranged on the top with a constant interval 7. For this reason, according to the said all-solid-state battery 11, the capacity | capacitance fall by the reduction | decrease in the amount of active materials and the increase in the capacity | capacitance reduction rate accompanying active material degradation may arise.

This is because in the all solid state battery 11 in which a plurality of battery units are arranged at a constant interval as described above, the amount of active material is reduced because the active material is cut together, and the active material is divided. When the active material of the part deteriorates, the lithium ion cannot be supplied from the active material of other battery units in the surroundings. As a result, the unit containing the deteriorated active material has a capacity even if the active material of the counter electrode is healthy. Decreases.
On the other hand, according to the all solid state battery of the embodiment of the present invention, the reduction in the amount of these active materials and the reduction in capacity are suppressed.

In the manufacturing method of the all-solid-state battery of the embodiment of the present invention, as shown in FIG.
1) a step of sputtering a positive electrode active material on a current collector foil;
2) A step of applying mesh-like masking on the positive electrode active material,
3) a step of sputtering a solid electrolyte on the positive electrode active material;
By including the step of 4) removing the masking, and 5) the step of attaching the negative electrode active material on the solid electrolyte, the all solid state battery of the embodiment of the present invention can be obtained.

On the other hand, in the manufacturing method outside the scope of the present invention, as shown in FIG.
1) Laminating current collector foil, positive electrode active material, solid electrolyte, negative electrode active material,
2) A step of bonding the obtained laminate to each other by hot pressing, and 3) a step of cutting the laminate excluding the current collector foil by etching or the like.
Therefore, according to the production method outside the scope of the present invention, an all-solid battery in which the active material layer is cut together with the solid electrolyte layer in step 3) is obtained. A decrease in the amount of active material and a decrease in capacity can occur.

The positive electrode active material is not particularly limited as long as it is an active material that can be used for a Li-ion battery, and may be layered, olivine-based, or spinel-type.
As the positive electrode active material, at least one transition metal selected from manganese, cobalt, nickel and titanium and a metal oxide containing lithium, such as lithium cobaltate (Li _x CoO ₂ ), lithium nickelate (Li _x NiO _2). ), Lithium nickel manganese cobaltate (Li _{1 + x} Ni _1/3 Mn _1/3 Co _1/3 O ₂ ), lithium nickel cobaltate (LiCo _0.3 Ni _0.7 O ₂ ), lithium manganate (Li _x Mn ₂ O _4), lithium titanate _{(Li 4/3 Ti 5/3 O 4)} , lithium manganese oxide compound _{(Li 1 + x M y Mn} 2-x-y O 4; M = Al, Mg, Fe, Cr, Co , Ni, Zn), lithium titanate _(Li x _TiO y), phosphate metal lithium _(LiMPO 4, M = Fe, n, Co, Ni), vanadium oxide _{(V 2 O} 5), molybdenum oxide _(MoO 3), titanium sulfide _(TiS 2), lithium cobalt nitride (LiCoN), lithium silicon nitride (LiCoN), lithium metal, lithium Alloys (LiM, M = Sn, Si, Al, Ge, Sb, P), lithium-storable intermetallic compounds (MgxM, M = Sn, Ge, Sb, or XySb, X = In, Cu, Mn) and their Derivatives.

The negative electrode active material is not particularly limited as long as it is an active material that can be used in a Li ion battery. For example, a metal, an alloy, or a metal compound, for example, a metal such as Li, Sn, Si, or In, lithium, titanium, and magnesium. Alternatively, alloys with aluminum, metal compounds such as oxides, sulfides or phosphorus compounds of the above metals or oxides, sulfides or phosphorus compounds of alloys or alloys with other metals such as SiO, SnO, SnS, SnP, Ti ₂ SnO _{6 and the} like, preferably lithium metal (Li), an alloy of lithium and titanium, magnesium or aluminum.

There is no restriction | limiting in particular as said solid electrolyte, A sulfide, an oxide, nitride, and a halide are mentioned, Especially an oxide solid electrolyte is mentioned suitably. The solid electrolyte may be crystalline, amorphous, or glass ceramic.
Examples of the solid electrolyte include lithium phosphate (Li ₃ PO ₄ ) and lithium phosphate oxynitride (LiPON) in which part of oxygen in the lithium phosphate is replaced with nitrogen.

  A metal foil such as SUS foil or Al foil can be used as the current collector for the positive electrode, and a metal foil such as SUS foil or Cu foil can be used as the current collector for the negative electrode.

As said masking, the net-like film | membrane which has the space | gap part for the solid electrolyte which consists of arbitrary materials and is filled with a post process can be used. Examples of the material include ceramic, metal, and polymer.
The masking removal can be performed by dissolving with a solvent or peeling off the net-like film.

Affixing the negative electrode active material onto the solid electrolyte is performed by, for example, placing a previously prepared negative electrode active material film on the solid electrolyte layer, and then usually placing a current collector foil (not shown) and then pressing. Can be implemented.
In the all solid state battery of the present invention, the positive electrode active material layer and the negative electrode active material layer are continuous without being cut at regular intervals like the all solid state battery in the prior art. Battery capacity can be increased.

Examples of the present invention will be described below.
The following examples are for illustrative purposes only and are not intended to limit the invention.

Example 1
An all-solid-state battery was fabricated by the steps shown in FIG. 4 using Al foil as the positive electrode current collector gold foil, LiCoO ₂ as the positive electrode active material, LiPON as the solid electrolyte, Li metal as the negative electrode active material, and a SUS film as the masking film. .
According to the above process, the production method is easy, the cost merit is large compared to the existing technology, and it is possible to suppress both the battery capacity reduction and the propagation when separation occurs between the active material and the solid electrolyte. It is possible to obtain an all-solid battery.

According to the present invention, it is possible to obtain an all-solid-state battery that can suppress both the battery capacity reduction and the propagation when peeling occurs between the active material and the solid electrolyte.
In addition, according to the present invention, it is possible to easily obtain an all-solid-state battery that can suppress both the battery capacity reduction and the propagation when peeling occurs between the active material and the solid electrolyte.

DESCRIPTION OF SYMBOLS 1 All-solid-state battery of embodiment of this invention 2 Positive electrode active material layer 3 Negative electrode active material layer 4 Solid electrolyte layer 5 Current collecting foil 6 Through-hole 7 Fixed space | interval 10 The conventionally well-known all-solid-state battery which does not have a through-hole 11 All-solid-state battery outside the range of 12 Battery unit 13 Other battery unit

Claims (6)

An all-solid battery having a solid electrolyte layer sandwiched between a positive electrode active material layer and a negative electrode active material layer, wherein the two active material layers are each continuous, and the solid electrolyte layer comprises the positive electrode active material layer and the positive electrode active material layer. It is divided in the multiple negative electrode active material layers by through-holes, the battery.   The all-solid-state battery according to claim 1, wherein the solid electrolyte is an oxide solid electrolyte. _3. The all-solid-state battery according to claim 1, wherein the solid electrolyte is lithium phosphate (Li ₃ PO ₄ ) or lithium phosphate oxynitride (LiPON) in which part of oxygen of the lithium phosphate is replaced with nitrogen. _4. .   The all-solid-state battery according to claim 1, wherein the positive electrode active material layer is made of a metal oxide containing lithium and at least one transition metal selected from manganese, cobalt, nickel, and titanium.   The all-solid-state battery according to claim 1, wherein the negative electrode active material layer is made of lithium metal (Li) or an alloy of lithium and titanium, magnesium, or aluminum. A method of manufacturing an all-solid battery,
A step of providing a mesh-like masking on one continuous active material layer of either the positive electrode active material layer or the negative electrode active material layer;
A step of forming a solid electrolyte layer by sputtering a solid electrolyte on one of the active material layers provided with the masking;
The method comprising: removing a masking to form a solid electrolyte layer divided into a plurality of parts; and pasting another continuous active material layer on the solid electrolyte layer.

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