BATTERY AND METHOD FOR ITS MANUFACTURING

Abstract

A main objective of the present invention is to provide a battery with excellent discharge capacity characteristics. The present invention achieves this objective by providing a battery that utilizes a deposition and dissolution reaction of metallic lithium as an anode reaction, wherein the battery comprises: layers in the order of an anode current collector, a metal layer, an electrolyte layer, and a layer of active cathode material in a thickness direction, wherein the metal layer contains a Li-Mg alloy phase and a Li-In alloy phase.

Description

Technical area

[0001] The present invention relates to a battery and a method for its production. State of the art

[0002] A battery typically comprises an electrolyte layer between a layer of cathode active material and a layer of anode active material. In the field of batteries, a battery that utilizes a deposition and dissolution reaction of metallic lithium as the anode reaction is also known. For example, Patent Literature 1 discloses a solid-state battery that utilizes the deposition and dissolution reaction of metallic lithium as the anode reaction. Citation listPatent literature

[0003] Patent Literature 1: Japanese Patent Application No. JP 2020-184513 A Summary of the inventionTechnical task

[0004] For batteries that utilize the deposition and dissolution reaction of metal lithium as the anode reaction, a general anode active material layer (a layer containing a particle of anode active material that absorbs and releases Li) is generally not arranged during battery manufacturing. Instead, the anode active material layer (Li-containing layer) is formed by the initial charge, which can slightly improve the energy density. However, for batteries that utilize the deposition and dissolution reaction of metal lithium as the anode reaction, there is room for further improvement in the discharge capacity characteristics.

[0005] The present invention has been made in view of the above circumstances, and a main object thereof is to provide a battery whose discharge capacity characteristics are excellent. Solution to the problem [1] A battery using a deposition and dissolution reaction of a metallic lithium as the anode reaction, the battery comprising: Layers in the order of an anode current collector, a metal layer, an electrolyte layer and a layer of an active cathode material in a thickness direction, wherein the metal layer contains a Li-Mg alloy phase and a Li-In alloy phase. [2] Battery according to point [1], wherein in the metal layer the Li-In alloy phase is distributed or dispersed in the Li-Mg alloy phase. [3] Battery according to item [1] or [2], wherein in the metal layer a proportion of In with respect to the total amount of In and Mg is 5 atom% or more and 60 atom% or less. [4] Battery according to any one of items [1] to [3], wherein in the layer of metal the proportion of In with respect to the total amount of In and Mg is 25 atomic% or more and 60 atomic% or less. [5] The battery according to any one of items [1] to [4], wherein the size of the Li-Mg alloy phase is 0.1 µm or more and 5 µm or less. [6] The battery according to any one of items [1] to [5], wherein the metal layer does not contain a binder. [7] The battery according to any one of items [1] to [6], wherein the electrolyte layer is a solid electrolyte layer containing a solid electrolyte. [8] The battery according to any one of items [1] to [7], wherein the solid electrolyte is a sulfide solid electrolyte. [9] A battery using a deposition and dissolution reaction of a metal lithium as an anode reaction, the battery comprising: Layers in the order of an anode current collector, a metal layer, an electrolyte layer and a layer of an active cathode material in a thickness direction, wherein the metal layer contains a Mg-In alloy.

[10] The battery according to item [9], wherein the metal layer comprises a metal phase which is a Mg-In alloy phase of the Mg-In alloy.

[11] The battery according to item [9] or

[10] , wherein the metal layer is a vapor or gas phase deposition layer.

[12] The battery according to item [9], wherein the metal layer contains a particle of the Mg-In alloy.

[13] A method of manufacturing a battery using a deposition and dissolution reaction of a metallic lithium as an anode reaction, the method comprising: a metal layer forming step comprising forming a metal layer comprising a Mg-In alloy phase by a vapor deposition method; and an assembling step comprising assembling the battery comprising layers in the order of an anode current collector, the metal layer, an electrolyte layer, and a cathode active material layer in a thickness direction.

[14] The method for manufacturing the battery according to item

[13] , further comprising a charging step of charging the battery to form a Li-Mg alloy phase and a Li-In alloy phase from the Mg-In alloy phase contained in the metal layer after the assembling step. Advantageous effects of the invention

[0006] The battery of the present invention has excellent discharge capacity characteristics. Short description of the drawing Fig. 1A and Fig. 1B are schematic cross-sectional views exemplifying the battery of the present invention. Fig.2A to 2D are explanatory views explaining the states at the time of charging the battery of the present invention. Fig. 3A to 3C are explanatory views explaining the states at the time of discharging the battery of the present invention. Fig. 4 is a flowchart illustrating the method for manufacturing the battery of the present invention. Fig. 5 is the result of a charge and discharge test in the evaluation cells manufactured in Examples 1 to 5 and Comparative Examples 1 and 2. Fig. 6 is the result of a charge and discharge test in the evaluation cells manufactured in Examples 1 to 5 and Comparative Examples 1 and 2. Fig. Figure 7 is a cross-sectional SEM image of the evaluation cell prepared in Example 3. Description of the embodiments

[0007] The battery and the method for manufacturing the same according to the present invention will be explained in detail below with reference to the drawings. Each of the drawings described below is a schematic view, and the size and shape of each section are exaggerated accordingly for clarity. A. Battery

[0008] Fig. 1A and Fig. 1B are schematic cross-sectional views illustrating the battery of the present invention. In particular, Fig. 1A is a schematic cross-sectional view illustrating the battery before the first charge or initial charge, and Fig. Figure 1B is a schematic cross-sectional view illustrating the battery after the first charge.

[0009] As in the Fig. 1A and Fig.1B, the battery comprises 10 layers in the order of anode current collector 1, metal layer 2, electrolyte layer 3 and layer 4 of active cathode material in the thickness direction D T . Normally, the cathode current collector 5 is arranged on the base of the layer 4 of active cathode material on the opposite side of the electrolyte layer 3. As in Fig. As shown in Figure 1A, the metal layer 2 in the battery 10 contains a Mg-In alloy prior to the first charge. The metal layer 2 is typically a vapor deposition layer comprising a Mg-In alloy phase. If the Fig. When the battery 10 shown in Figure 1A is charged, the Mg-In alloy phase reacts with Li, and a Li-Mg alloy phase and a Li-In alloy phase are formed from the Mg-In alloy phase. As shown in Fig. As shown in Figure 1B, the metal layer 2 in the battery 10 after the first charge contains the Li-Mg alloy phase and the Li-In alloy phase.

[0010] According to the present invention, the metal layer comprises Mg and In, and thus, a battery with excellent discharge capacity characteristics can be obtained. As described above, in the battery that uses the deposition and dissolution reaction of the metal lithium as an anode reaction, a general anode active material layer (such as a layer containing a particle of anode active material that absorbs and releases Li) is not normally disposed during battery manufacture, but the anode active material layer (Li-containing layer) is formed by the first charge, thereby easily improving the energy density. However, in the battery that uses the deposition and dissolution reaction of the metal lithium as an anode reaction, there is room for further improvement in the discharge capacity characteristics.

[0011] In contrast, the present invention uses the metal layer comprising Mg and In. By using such a metal layer, excellent discharge capacity characteristics can be obtained. The reason for obtaining the excellent discharge capacity characteristics is presumably that, when using the metal layer comprising Mg and In, an increase in resistance in the anode in the final phase of discharge can be prevented. The effects that can be obtained with the present invention will be described below with reference to the Fig. 2A to 2D and Fig. 3A to 3C are explained in detail.

[0012] As in Fig.As shown in Figure 2A, the battery comprises 10 layers in the order of anode current collector 1, metal layer 2, electrolyte layer 3, cathode active material layer 4, and cathode current collector 5 in a thickness direction. The metal layer 2 comprises a Mg-In alloy phase. Next, as shown in Fig. 2B, at the beginning of the charging of the battery 10, a Li-In alloy phase is first formed from a portion of the Mg-In alloy phase. Since the reaction potential of Li intercalation and desorption of In is higher than that of Mg, In reacts faster with Li than Mg, and the Li-In alloy phase is formed. Next, as shown in the Fig. 2C and Fig.As shown in Figure 2D, as the battery 10 progresses in charging, a Li-Mg alloy phase is formed in addition to the Li-In alloy phase. The Li-In alloy phase is formed before the Li-Mg alloy phase, thus maintaining the state in which the Li-In alloy phase is dispersed within the Li-Mg alloy phase.

[0013] Next, as in Fig. As shown in Figure 3A, when the charged battery 10 is discharged, the Li contained in the metal layer 2 moves through the electrolyte layer 3 to the active cathode material layer 4. Since the reaction potential of Li intercalation and Mg desorption is lower than that of In, Li is first desorbed from the Li-Mg alloy phase. As shown in Fig. As shown in Figure 3B, the Li-In alloy phase exhibits high Li-ion conductivity, forming an excellent ion conduction path. Fig.As shown in Figure 3C, the Li-In alloy phase is presumably maintained even in the final stages of discharge, inhibiting the increase in resistance in the anode. As a result, it is assumed that the excellent discharge capacity characteristics can be maintained.

[0014] The battery of the present invention can be roughly divided into two embodiments depending on the state of charge (SOC). The first embodiment and the second embodiment of the battery of the present invention will be explained separately below. 1. First embodiment

[0015] As in Fig. As shown in Figure 3A, the battery 10 in the first embodiment includes layers in the order of anode current collector 1, metal layer 2, electrolyte layer 3, and cathode active material layer 4 in a thickness direction. Furthermore, the metal layer 2 contains a Li-Mg alloy phase and a Li-In alloy phase. (1) Anode

[0016] The anode in the first embodiment includes an anode current collector. Examples of the material for the anode current collector may include SUS, copper, nickel, and carbon. Examples of the shape of the anode current collector may include a foil shape. The thickness of the anode current collector is, for example, 1 µm or more and 500 µm or less.

[0017] The anode comprises a metal layer. The metal layer contains a Li-Mg alloy phase and a Li-In alloy phase. The Li-Mg alloy phase is a metal phase of an alloy comprising Li and Mg, and it may be a metal phase of a binary alloy comprising Li and Mg, or it may be a metal phase of an alloy comprising other elements in addition to Li and Mg. In the latter case, it is preferable that Li and Mg are the main components in the Li-Mg alloy phase. "Main components" means that the proportion (in atomic%) is the highest among the components contained in the metal phase. For example, in the Li-Mg alloy phase, the proportion of Li and Mg to the total of all elements is 50 atomic% or more, may be 70 atomic% or more, and may be 90 atomic% or more.

[0018] The Li-In alloy phase is a metal phase of an alloy comprising Li and In, and it may be a metal phase of a binary alloy comprising Li and In, or it may be a metal phase of an alloy comprising other elements in addition to Li and In. In the latter case, it is preferable that Li and In are the main components in the Li-In alloy phase. In the Li-In alloy phase, the proportion of Li and In to the total of all elements is, for example, 50 atomic% or more, may be 70 atomic% or more, and may be 90 atomic% or more.

[0019] The metal layer contains both the Li-In alloy phase and the Li-Mg alloy phase. It is especially preferable for the metal layer to have the Li-In alloy phase distributed throughout the Li-Mg alloy phase. In other words, it is preferable to form a sea-island structure, with the Li-Mg alloy phase as the sea and the Li-In alloy phase as the island. This is to inhibit the increase in resistance at the anode during the final discharge stage. There are no specific restrictions on the size of the Li-In alloy phase, but it is, for example, 0.1 μm or more and 5 μm or less. The size of the Li-In alloy phase can be obtained from the In distribution by SEM-EDX. The size of the Li-In alloy phase is an average value of the sizes of 100 or more measured samples.

[0020] In the metal layer, there are no special restrictions on the proportion of In with respect to the total amount of In and Mg, that is, In / (In+Mg). For example, In / (In+Mg) can be 5 atom% or more, 10 atom% or more, 15 atom% or more, 20 atom% or more, and 25 atom% or more. If the value of In / (In+Mg) is too small, there is a possibility that the effect of improving the discharge capacity characteristics by In will not be sufficiently expressed. Incidentally, for example, In / (In+Mg) is 90 atom% or less, may be 80 atom% or less, may be 70 atom% or less, and may be 60 atom% or less. If the value of In / (In+Mg) is too large, there is a possibility that the effect of improving the capacity stability by Mg will not be sufficiently achieved.

[0021] It is preferable that the metal layer does not contain any conductive material. It is also preferable that the metal layer does not contain a binder. A lithium phase may also be formed within the metal layer. A deposited lithium layer may also be formed between the metal layer and the electrolyte layer. A deposited lithium layer may also be formed between the metal layer and the anode current collector.

[0022] The metal layer is usually a dense layer. The void of the metal layer (the proportion of the void area in the cross-section of the metal layer) is, for example, 5% or less, may be 3% or less, and may be 1% or less. Also, in the first embodiment, the thickness of the metal layer is not particularly limited, but is, for example, 5 μm or more and 30 μm or less.

[0023] As in Fig.3A, the metal layer 2 can be in direct contact with the anode current collector 1. Likewise, the metal layer 2 can be in direct contact with the electrolyte layer 3. Although not shown in detail, an additional layer can be arranged between the metal layer and the anode current collector. Likewise, an additional layer can be arranged between the metal layer and the electrolyte layer. As shown in Fig. As shown in Figure 3C, the metal layer 2 may contain the Li-Mg alloy phase and the Li-In alloy phase after discharge. It may depend on the state of charge, but the metal layer may contain a Mg phase that does not include Li and the Li-In alloy phase after discharge. Likewise, the metal layer may contain a Mg phase that does not include Li and an In phase that does not include Li after discharge. (2) Cathode

[0024] The cathode in the first embodiment comprises a cathode current collector and a layer of active cathode material. The layer of active cathode material contains at least one active cathode material. Furthermore, the layer of active cathode material may contain at least one electrolyte, a conductive material, and / or a binder.

[0025] Examples of the cathode active material may include an oxide active material. Examples of the oxide active material may include a rock salt bed type active material such as LiCoO2 and LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2, a spinel-type active material such as LiMn2O4 and Li4Ti5O 12 and an olivine-type active material such as LiFePO4. Examples of the shape of the active cathode material may include a granular form. The average particle size (D 50) of the active cathode material is, for example, 0.5 µm or more and 50 µm or less. The average particle size (D 50 ) refers to a volume accumulation particle size measured using a laser diffraction particle distribution measuring device.

[0026] Examples of the electrolyte may include a solid electrolyte. Examples of the solid electrolyte may include an inorganic solid electrolyte such as a sulfide solid electrolyte, an oxide solid electrolyte, and a halide solid electrolyte. The sulfide solid electrolyte preferably contains sulfur (S) as a main component of the anion element. The oxide solid electrolyte preferably contains oxygen (O) as a main component of the anion element. The halide solid electrolyte preferably contains halogen (X) as the main component of the anion element. Among them, the sulfide solid electrolyte is preferable.

[0027] The sulfide solid electrolyte preferably contains a Li element, an M element (M being at least one of P, Sn, Al, Zn, In, Ge, Si, Sb, Ga, and Bi), and an S element. The sulfide solid electrolyte may also contain a halogen element such as F, Cl, Br, and I. Furthermore, a portion of an S element may be replaced by an O element in the sulfide solid electrolyte.

[0028] The sulfide solid electrolyte can be a glass-based (amorphous) sulfide solid electrolyte, a glass-ceramic-based sulfide solid electrolyte, and a crystal-based sulfide solid electrolyte. Examples of the crystal phase contained in the sulfide solid electrolyte can be an LGPS-type crystal phase, a thio-LISICON-type crystal phase, and an argyrodite-type crystal phase.

[0029] Examples of the sulfide solid electrolyte can be Li2S-P2S5, Li2S-P2S5-LiI, Li2S-P2S5-GeS2, Li2S-P2S5-Li2O, Li2S-P2S5-Li2O-LiI, Li2S-P2S5-LiI-LiBr, Li2S-SiS2, Li2S-SiS2-LiI, Li2S-SiS2-LiBr, Li2S-SiS2-LiCI, Li2S-SiS2-B2S3-LiI, Li2S-SiS2-P2S5-LiI, Li2S-B2S3, Li2S-P2S5-Z m S n (provided that m, n is a positive number and Z is one of Ge, Zn and Ga), Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li x MO y (provided that x, y is a positive number and M is one of P, Si, Ge, B, Al, Ga and In).

[0030] Other examples of the solid electrolyte may include an organic solid electrolyte such as a polymer electrolyte and a gel electrolyte. An electrolyte solution (liquid electrolyte) may also be used as the electrolyte.

[0031] Examples of the conductive material may include a carbon material. Examples of the carbon material may include a particulate carbon material such as acetylene black (AB) and Ketjen black (KB), and a fibrous carbon material such as carbon fiber, carbon nanotubes (CNT), and carbon nanofiber (CNF). Further, examples of the binder may include a rubber-based binder such as butylene rubber (BR) and styrene-butadiene rubber (SBR), and a fluoride-based binder such as polyvinylidene fluoride (PVDF). The thickness of the cathode active material layer is, for example, 1 μm or more and 500 μm or less.

[0032] Examples of the material for the cathode current collector may include SUS, aluminum, nickel, and carbon.

[0033] Examples of the shape of the cathode current collector may include a foil shape. The thickness of the cathode current collector is, for example, 1 µm or more and 500 µm or less. (3) Electrolyte layer

[0034] The electrolyte layer in the first embodiment contains at least one electrolyte. The electrolyte has the same composition as that described above in "(2) Cathode." In particular, the electrolyte layer preferably contains a solid electrolyte as the electrolyte. In other words, the electrolyte layer is preferably a solid electrolyte layer containing a solid electrolyte. A battery including the solid electrolyte layer may be referred to as a solid-state battery. Furthermore, the solid electrolyte layer may contain a binder in addition to the solid electrolyte. The binder has the same composition as described above in "(2) Cathode." Furthermore, the thickness of the electrolyte layer is, for example, 1 μm or more and 500 μm or less. (4) Battery

[0035] The battery of the first embodiment includes layers in the order of an anode current collector, a metal layer, an electrolyte layer, and a cathode active material layer in a thickness direction. Furthermore, the battery typically includes an outer package for storing these elements. Examples of the outer package include a laminate-type outer package and a case-type outer package.

[0036] The application of the battery is not particularly limited, and examples may include a power source for vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), battery electric vehicles (BEVs), gasoline-powered automobiles, and diesel-powered automobiles. In particular, it is preferably used as a power source for driving hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and battery electric vehicles (BEVs). The battery can also be used as a power source for moving bodies other than vehicles (e.g., railway vehicles, ships, and aircraft) and as a power source for electronic products such as information processing equipment. 2. Second embodiment

[0037] As in Fig.As shown in Figure 2A, the battery 10 of the second embodiment includes layers in the order of anode current collector 1, metal layer 2, electrolyte layer 3, and cathode active material layer 4 in a thickness direction. Furthermore, the metal layer 2 contains a Mg-In alloy. Otherwise, the details of each element except the metal layer 2 are the same as those described above for the first embodiment.

[0038] The metal layer contains a Mg-In alloy. The Mg-In alloy is an alloy comprising Mg and In, and it may be a binary alloy comprising Mg and In, or it may be an alloy comprising other elements in addition to Mg and In. In the latter case, it is preferable that Mg and In are the main components in the Mg-In alloy. In the Mg-In alloy, the proportion of Mg and In to the total of all elements is, for example, 50 atomic% or more, may be 70 atomic% or more, and may be 90 atomic% or more.

[0039] The metal layer may comprise a metal phase of the Mg-In alloy (Mg-In alloy phase) and contain particles of the Mg-In alloy. The particles of the Mg-In alloy are preferably nanoparticles whose average particle size D 501 µm or less. In addition, there are no particular restrictions on the proportion of In with respect to the total amount of In and Mg, that is, In / (In + Mg) in the metal layer. The preferable range of In / (In + Mg) is in the same range as that described in the first embodiment above. In addition, it is preferable that the metal layer does not contain a conductive material. It is also preferable that the metal layer does not contain a binder. In addition, in the second embodiment, the metal layer does not normally contain Li.

[0040] The metal layer is usually a dense layer. The void of the metal layer (proportion of the area of ​​the void in the cross-section of the metal layer) is, for example, 5% or less, may be 3% or less, and may be 1% or less. The metal layer may also be a vapor-deposited layer. It is preferable that the metal layer adheres to the anode current collector. In other words, it is preferable that the metal layer be disposed so as to cover the surface of the anode current collector. A member comprising the anode current collector and the metal layer disposed on the anode current collector may be called a covered current collector. In the second embodiment, there are no particular restrictions on the thickness of the metal layer, and it may be, for example, 30 nm or more and 5 μm or less, 100 nm or more and 3 μm or less, or 500 nm or more and 2 μm or less.

[0041] The battery of the second embodiment comprises layers in the order of an anode current collector, a metal layer, an electrolyte layer, and a cathode active material layer in the thickness direction. Furthermore, the battery typically includes an outer package for storing these elements. The components other than the metal layer have the same properties as those described above under "1. First Embodiment." B. Method for producing a battery

[0042] Fig. Figure 4 is a flow chart illustrating the method for manufacturing the battery of the present invention. As shown in Fig.As shown in Figure 4, a metal layer comprising a Mg-In alloy phase is formed by a vapor deposition process (a metal layer formation step). Thereafter, the battery comprising layers in the order of an anode current collector, the metal layer, an electrolyte layer, and a cathode active material layer in a thickness direction is assembled (an assembly step). This, for example, produces the Fig. 1A is obtained. The battery is then charged to form a Li-Mg alloy phase and a Li-In alloy phase from the Mg-In alloy phase contained in the metal layer (a charging step). This produces, for example, the Fig. 1B shown battery 10.

[0043] According to the present invention, the specified metal layer is formed and thus a battery with excellent discharge capacity characteristics is obtained. 1. Step to form a metal layer

[0044] The metal layer forming step of the present invention is a step of forming a metal layer comprising an Mg-In alloy phase by a vapor deposition method. A metal layer obtained by the vapor deposition method is a vapor deposition layer.

[0045] Examples of vapor deposition processes include physical vapor deposition (PVD) such as ion plating, spattering, and vacuum vapor deposition. It is preferable that a Mg metal and an In metal are each prepared and subjected to binary deposition.

[0046] In the present invention, it is preferable that the metal layer be formed on the anode current collector by the vapor deposition method. This is because the anode current collector is very smooth, and a metal layer with a uniform thickness can be obtained. In this case, the metal layer can be formed directly on the anode current collector. Meanwhile, the metal layer can be formed on the anode current collector with an additional layer (such as an additional vapor deposition layer) interposed therebetween. In the present invention, the metal layer can be formed on the solid electrolyte layer by the vapor deposition method. In this case, the metal layer can be formed directly on the solid electrolyte layer.The metal layer may also be formed on the solid electrolyte layer with an additional layer (such as an additional vapor deposition layer) interposed therebetween. 2. Assembly step

[0047] The assembly step of the present invention is a step of assembling the battery, which includes layers in the order of an anode current collector, a metal layer, an electrolyte layer, and a cathode active material layer in a thickness direction. There are no particular restrictions on the method of assembling the battery, and known methods can be used. 3. Loading step

[0048] The charging step of the present invention is a step of charging the battery to form a Li-Mg alloy phase and a Li-In alloy phase from the Mg-In alloy phase included in the metal layer. The conditions for charging the battery are appropriately selected depending on the nature of the battery. 4. Battery

[0049] The battery obtained by each of the steps described above has the same contents as the one described in “A. Battery”.

[0050] The present invention is not limited to the embodiments. The embodiments are for illustrative purposes, and all other variations are intended to be included within the technical scope of the present invention if they have substantially the same nature as the technical idea described in the claims of the present invention and have a similar operation and effect. Examples[Example 1]<Herstellung der Kathode>

[0051] Lithium nickel cobalt aluminate (NCA) was prepared as a cathode active material, a Li2S-P2S5-based sulfide solid electrolyte containing LiI and LiBr was prepared as a solid electrolyte (SE), a PVDF-based binder was prepared as a binder, and a vapor-phase grown carbon fiber (VGCF) was prepared as a conductive material. Next, each material was added to butyl butyrate in a weight ratio of NCA:SE:binder:conductive material = 84.7:13.4:0.6:1.27 to obtain a cathode paste. The resulting cathode slurry was coated onto a cathode current collector (aluminum foil) with a pasting gap of 225 µm, then temporarily dried at 60 °C, and then dried at 165 °C for 1 hour. This resulted in a cathode comprising a cathode current collector and a layer of active cathode material.The weight of the active cathode material layer was 18.7 mg / cm. 2 and the designed capacity of the active cathode material layer was 3.0 mAh / cm 2 . <Herstellung einer Festelektrolytschicht>

[0052] A Li2S-P2S5-based sulfide solid electrolyte comprising LiI and LiBr was prepared as the solid electrolyte (SE), and a PVDF-based binder was prepared as the binder. Next, each material was added to butyl butyrate in a weight ratio of SE:binder = 92.6:7.4 to obtain a slurry for the solid electrolyte layer. The obtained slurry was adhered to a release film with a pasting gap of 325 μm, then dried at room temperature for 3 hours and then at 165 °C for 1 hour. This formed a laminated body comprising the release film and the solid electrolyte layer. The obtained laminated body was punched to Φ14.5 mm, and the solid electrolyte layers of two punched elements were overlapped and then pressed with a pressure of 7 tons. After pressing, the release films positioned on both surfaces were peeled off and an independent solid electrolyte layer was obtained. <Herstellung der Anode>

[0053] A stainless steel foil (SUS foil) was prepared as the anode current collector. A layer of Mg-In alloy (thickness: 1.0 µm) was formed on the SUS foil by binary deposition using an ion plating process. The target composition in the layer was Mg:In ​​= 90:10 (atomic percentage basis), and the actual composition was Mg:In ​​= 86:14 (atomic percentage basis). This resulted in an anode comprising the anode current collector and the metal layer. <Herstellung einer Bewertungszelle>

[0054] The resulting cathode was punched to Φ11.28 mm, and the resulting anode to Φ14.5 mm. An independent layer of solid electrolyte was sandwiched between them, and an Al cathode strip and a Ni anode strip were installed and then vacuum-sealed in a laminated film. A pressure of 392 MPa was applied to the sealed cell by cold isostatic pressing (CIP). The cell was then clamped at 1 MPa using a constant-pressure jig in which a spring was inserted, so that the clamping pressure remained constant regardless of the cell's volume change. This resulted in an evaluation cell. [Example 2]

[0055] An evaluation cell was obtained in the same manner as in Example 1, except that the target composition in the metal layer was changed to Mg:In ​​= 67:33 (atomic % basis). The actual composition in the metal layer was Mg:In ​​= 64:36 (atomic % basis). [Example 3]

[0056] An evaluation cell was obtained in the same manner as in Example 1, except that the target composition in the metal layer was changed to Mg:In ​​= 50:50 (atomic % basis). The actual composition in the metal layer was Mg:In ​​= 46:54 (atomic % basis). [Example 4]

[0057] An evaluation cell was obtained in the same manner as in Example 1, except that the target composition in the metal layer was changed to Mg:In ​​= 33:67 (atomic % basis). The actual composition in the metal layer was Mg:In ​​= 34:66 (atomic % basis). [Example 5]

[0058] An evaluation cell was obtained in the same manner as in Example 1, except that the target composition in the metal layer was changed to Mg:In ​​= 10:90 (atomic % basis). The actual composition in the metal layer was Mg:In ​​= 12:88 (atomic % basis). [Comparison example 1]

[0059] An evaluation cell was obtained in the same manner as in Example 1 except that a metal layer containing a Mg metal was formed as the metal layer. [Comparison example 2]

[0060] An evaluation cell was obtained in the same manner as in Example 1 except that a metal layer containing an In metal was formed as the metal layer. [Evaluation]<Lade- und Entladetest>

[0061] The evaluation cells obtained in Examples 1 to 5 and Comparative Examples 1 to 2 were first subjected to a charging and discharging process at 60 °C with a constant current (current density: 0.15 mA / cm 2 , corresponds to approximately 0.05 C) - constant voltage (cut-off current density: 0.03 mA / cm 2 , corresponds to approximately 0.01 C) Test in a cut-off voltage range: 4.2 V to 3.0 V.

[0062] As a cycle test, a test with constant current (current density: 0.60 mA / cm 2 , corresponds to approximately 0.05 C) and constant voltage (only during charging, cut-off current density: 0.03 mA / cm 2 , corresponding to approximately 0.01 C) at 25 °C in a cut-off voltage range of 4.2 V to 3.0 V. The results are shown in Fig. 5. In addition, the initial discharge capacity and the discharge capacity after 20 cycles in the cycle test are shown in Table 1 and Fig. 6 shown. [Table 1] Metal layer composition [atom%] initial discharge capacity [mAh / cm 2 ] Discharge capacity after 20 cycles [mAh / cm 2 ] Comparison example 1 Mg:ln = 100:0 1,06 0,81 Comparison example 2 Mg:ln = 0:100 1,89 1,26 Example 1 Mg:ln = 86:14 1,89 1,46 Example 2 Mg:ln = 64:36 2,18 1,77 Example 3 Mg:ln = 46:54 2,19 1,88 Example 4 Mg:ln = 34:66 2,28 1,20 Example 5 Mg:ln = 12:88 2,14 1,19

[0063] As shown in Table 1, Fig. 5 and Fig. 6, a higher discharge capacity was obtained in Examples 1 to 5 than in Comparative Examples 1 and 2. More specifically, as shown in Fig.As shown in Figure 6, in Examples 1 to 5, a discharge capacity higher than a discharge capacity assumed from a straight line connecting Comparative Examples 1 and 2 was obtained. In Examples 1 to 5, the discharge capacity after 20 cycles of Examples 1 to 3 was maintained high, and it was confirmed that they were superior in cycle characteristics. In particular, it was confirmed that both the initial discharge capacity and the discharge capacity after 20 cycles of Examples 2 and 3 were remarkably high. <rem-beobachtung>

[0064] A cross-sectional observation with a scanning electron microscope (SEM) was performed on the evaluation cell obtained in Example 3. Specifically, a first charge was carried out at 60 °C under the same conditions as above, and SEM observation of the cross-section in a secondary electron image was performed with an applied voltage of 5 kV. The results are shown in Fig. 7. As shown in Fig. As shown in Figure 7, the metal layer disposed between the solid electrolyte layer and the anode current collector increased from 1.0 μm before the first charge to about 15 μm. This occurred because the Mg and In comprising the metal layer were each alloyed with Li. Although not shown in detail, an element distribution analysis by energy-dispersive X-ray spectroscopy (EDX) confirmed that the magnesium was relatively uniformly distributed in the metal layer. In contrast, it was confirmed that the indium was locally distributed. In other words, it was confirmed that the sea-island structure, in which the Li-Mg alloy phase was the sea and the Li-In alloy phase was the island, was formed.

[0065] The reaction potential of Li intercalation and Mg desorption is lower than 0.1 V (vs. Li / Li + ), and the reaction potential of Li intercalation and desorption of In is about 0.1 V to 0.6 V (vs. Li / Li + ). Considering such a relationship, it is assumed that Li desorption from the Li-Mg alloy phase occurred first during discharge, and at this time, the Li-In alloy phase acted as a Li ion conduction pathway to increase the discharge capacity. Specifically, in Example 3, it is assumed that the state of the locally dispersed Li-In alloy phase had an effect on the Li ion conductivity. Considering the binary phase diagram of the Mg-In alloy, the Mg-In alloy (before the first charge) in Example 3 was in a state comprising the β'' phase while comprising a plurality of other β phases, and such a state had an influence on the dispersion state of the Li-In alloy phase after the first charge. List of reference symbols 1 anode current collector 2 metal layer 3 Electrolyte layer 4 layer of active cathode material 5 Cathode current collector 10 Battery QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2020-184513 A

[0003]

Claims

[1] Battery that uses a deposition and dissolution reaction of a metal lithium as an anode reaction, whereby the battery characterized by is that it includes: Layers in the order of an anode current collector, a metal layer, an electrolyte layer and a layer of active cathode material in a thickness direction, wherein the metal layer contains a Li-Mg alloy phase and a Li-In alloy phase. [2] Battery according to claim 1, characterized by that in the metal layer the Li-In alloy phase is dispersed in the Li-Mg alloy phase. [3] Battery according to claim 1 or 2, characterized by that in the metal layer, a proportion of In with respect to the total amount of In and Mg is 5 atomic% or more and 90 atomic% or less. [4] Battery according to one of claims 1 to 3, characterized by that the metal layer does not contain a binder. [5] Battery according to one of claims 1 to 4, characterized by that the electrolyte layer is a solid electrolyte layer containing a solid electrolyte. [6] Battery that uses a deposition and dissolution reaction of a metal lithium as an anode reaction, the battery characterized by is that it includes: Layers in the order of an anode current collector, a metal layer, an electrolyte layer and a layer of active cathode material in a thickness direction, wherein the metal layer contains a Mg-In alloy. [7] Battery according to claim 6, characterized by that the metal layer comprises a metal phase which is a Mg-In alloy phase of the Mg-In alloy. [8] Battery according to claim 7, characterized by that the metal layer is a vapor deposition layer. [9] Battery according to claim 6, characterized bythat the metal layer contains a particle of the Mg-In alloy. [10] A method of manufacturing a battery using a deposition and dissolution reaction of a metallic lithium as an anode reaction, the method comprising characterized by is that it includes: a metal layer forming step of forming a metal layer comprising a Mg-In alloy phase by a vapor deposition method; and an assembly step of assembling the battery comprising layers in the order of an anode current collector, the metal layer, an electrolyte layer, and a cathode active material layer in a thickness direction.

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