LITHIUM-ION BATTERY

Abstract

Lithium-ion battery (10) comprising a cathode active material layer (1) containing a cathode active material, an anode active material layer (2) containing an anode active material, and an electrolyte layer (3) formed between the cathode active material layer (1) and the anode active material layer (2), characterized in that The anode active material comprises: at least one Sr element and one S element; and a perovskite-type crystal phase belonging to a space group of I4 / mmm; and a molar ratio of the S element to the Sr element is greater than 0.1.

Description

Technical field

[0001] The present disclosure relates to a lithium-ion battery. State of the art

[0002] In recent years, battery development has been actively promoted. For example, the automotive industry has focused on developing batteries for battery-electric vehicles or hybrid-electric vehicles, as well as active materials for battery use.

[0003] For example, non-patented literature 1 discloses a solid-state battery with an anode made of Li4Ti5O 12 (LTO) as an anode active material, carbon nanotubes, and a solid electrolyte. Non-patent literature 2 describes the effects of sulfur doping on the structural, magnetic, and transport properties of Sr₂FeMoO₆. DE 10 2011 014 958 A1 discloses a yellow phosphor with the chemical formula (A 1-x-y Cex B y ) 2Ca 1-z Sr z F4S2. CN 1 790 554 A discloses a transparent, conductive material with the chemical formula Sr3Cu2Sc2O5S2. Bibliography Non-patent literature Non-patent literature 1: So Yubuchi et al., “Allsolid-state cells with Li4Ti5O 12 / carbon nanotube composite electrodes prepared by infiltration with argyrodite sulfide-based solid electrolytes via liquid-phase processing”, Journal of Power Sources, 417 (2019) 125-131 Non-patent literature 2: HUO, Guoyan ; DING, Lei ; LI, Zhenxing: Structural, magnetic and transport properties of S doping in Sr2FeMoO6 compound. In: Solid state sciences, Vol. 76, 2018, pp. 85-91. ISSN 1293-2558 Overview of the Revelation Technical Task

[0004] Although LTO exhibits excellent capacity properties, it possesses neither electron nor ionic conductivity. Therefore, when using such an anode active material, which lacks both electron and ionic conductivity, a conductive material providing electron conductivity and an electrolyte providing ionic conductivity are typically added to the anode. However, the addition of these materials carries the risk of reduced battery capacity if the proportion of anode active material in the anode is decreased.

[0005] The present disclosure was made in view of the above circumstances, and a main purpose of this disclosure is to provide an anode active material with excellent electronic and ionic conductivity. Solution to the task

[0006] This problem is solved by the subject matter of the independent claim. Further developments of the invention are the subject matter of the dependent claims. The present disclosure also provides a lithium-ion battery comprising a cathode active material layer containing a cathode active material, an anode active material layer containing an anode active material, and an electrolyte layer formed between the cathode active material layer and the anode active material layer, wherein the anode active material comprises: at least one Sr element and one S element, and a perovskite-type crystal phase belonging to a space group of I4 / mmm, and a molar ratio of the S element to the Sr element is greater than 0.1.

[0007] According to the present disclosure, the anode active material layer contains the specified anode active material, and thus the lithium-ion battery can exhibit excellent capacity characteristics.

[0008] In the revelation, the lithium-ion battery could be a solid-state lithium-ion battery.

[0009] In the disclosure, the anode active material layer can contain neither a conductive material nor a solid electrolyte. Beneficial effects of revelation

[0010] The present disclosure shows an effect that provides an anode active material with excellent electronic and ionic conductivity. Brief description of the drawings Fig. Figure 1 is a flowchart showing an example of the process for producing the anode active material in the present disclosure. Fig. Figure 2 is a schematic cross-sectional view showing an example of the lithium-ion battery in the present disclosure. Fig. Figure 3 is a diagram showing the X-ray diffraction (XRD) patterns of Example 1 and Comparison Example 1. Fig. Figure 4 is a diagram showing a charging and discharging curve for each current value of Example 1. Fig. Figure 5 is a diagram that plots the capacity per current value of examples 1 to 5 and the comparison example 1. Description of the embodiments

[0011] The anode active material, the process for producing the anode active material and the lithium-ion battery in the present disclosure are described in detail below. A. Anode active material

[0012] The anode active material in the present disclosure is an anode active material intended for use in a lithium-ion battery, wherein the anode active material comprises: at least one Sr element and one S element, and a perovskite-type crystal phase belonging to a space group of I4 / mmm, and a molar ratio of the S element to the Sr element is greater than 0.1.

[0013] According to the present disclosure, an anode active material can exhibit excellent electronic and ionic conductivity, since the ratio of the S element to the Sr element is greater than the specified value and the specified crystal phase is included.

[0014] As described in the aforementioned non-patent literature 1, LTO is known as a high-capacity anode active material. However, since LTO possesses neither electronic nor ionic conductivity, a conductive material and an electrolyte are typically added to the anode. In this case, there is a risk that the battery capacity may be reduced because the proportion of anode active material in the anode decreases. Meanwhile, the inventor of the present disclosure has found that the anode active material exhibits excellent electronic and ionic conductivity. With such an anode active material, the anode still does not need to contain a conductive material or an electrolyte, and thus the proportion of anode active material in the anode can be increased. As a result, a lithium-ion battery can exhibit excellent capacity characteristics.

[0015] The anode active material in the present disclosure comprises at least one strontium (Sr) element and one strontium (S) element. In the anode active material, the molar ratio of the S element to the Sr element is greater than 0.1; for example, it is 0.5 or greater, may be 1 or greater, and may be 1.5 or greater. Conversely, the molar ratio may be, for example, 2.0 or less. If the molar ratio is 0.1 or less, the anode active material will not have excellent ionic conductivity.

[0016] Furthermore, the anode active material in the present disclosure may additionally contain an oxygen element. If the anode active material contains an oxygen element, the molar ratio (S / O) of the sulfur element to the oxygen element is, for example, 0.04 or greater, may be 0.1 or greater, may be 0.2 or greater, and may be 0.3 or greater. Meanwhile, the S / O ratio is, for example, 1 or less, may be 0.7 or less, and may be 0.5 or less.

[0017] Furthermore, the anode active material in the present disclosure can additionally comprise a metallic element M, which is other than an Sr element and an S element. The M is preferably at least one of Nb, Zr, Mn, Sn, Mo, Fe, and Ti. In particular, the M is preferably at least Fe and Ti. The molar ratio (Fe / Ti) of Fe to Ti is, for example, 0.1 or greater, may be 0.5 or greater, and may be 0.9 or greater. Meanwhile, the Fe / Ti ratio is, for example, 6 or less, may be 4 or less, and may be 2 or less.

[0018] The composition of the anode active material in the present disclosure is not particularly restricted, but is preferably characterized by, for example, (Sr 1-x M 1 x ) a M 2 b (O 1-y S y+α ) c represented in the formula M 1 at least one of Nb, Zr, Mn, Sn and Mo. Also M 2at least one of Fe and Ti. Furthermore, "a" is, for example, 1.5 or greater, can be 1.7 or greater, and can be 1.9 or greater. Meanwhile, "a" is, for example, 2.5 or less, can be 2.3 or less, and can be 2.1 or less. "b" is, for example, 1.5 or greater, can be 1.7 or greater, and can be 1.9 or greater. Meanwhile, "b" is, for example, 2.5 or less, can be 2.3 or less, and can be 2.1 or less. "c" is, for example, 5.5 or greater, can be 5.7 or greater, and can be 5.9 or greater. Meanwhile, "c" is, for example, 6.5 or less, can be 6.3 or less, and can be 6.1 or less. Furthermore, "x" is, for example, 0.2 or greater, and can be 0.4 or greater. Meanwhile, "x" is, for example, less than 1, can be 0.8 or less, and can be 0.6 or less. Furthermore, "y" is, for example, 0.05 or greater, can be 0.10 or greater, and can be 0.20 or greater.Meanwhile, "y" is, for example, 1.00 or less, can be 0.80 or less, can be 0.60 or less, and can be 0.40 or less. "α" can be 0 and can be greater than 0. In the latter case, "α" is, for example, 0.03 or greater, and can be 0.10 or greater. Meanwhile, "α" is, for example, 0.40 or less, and can be 0.30 or less.

[0019] The anode active material in the present disclosure comprises a perovskite-type crystal phase belonging to a space group of I4 / mmm. Specifically, the anode active material preferably has the perovskite-type crystal phase belonging to the space group I4 / mmm as a major phase. "Having the perovskite-type crystal phase belonging to the space group I4 / mmm as a major phase" means that the peak belonging to the aforementioned crystal phase exhibits the greatest diffraction intensity among the peaks observed in an X-ray diffraction measurement. The proportion of the aforementioned crystal phase to all crystal phases in the anode active material is, for example, 50 mol% or more, may be 70 mol% or more, may be 90 mol% or more, and may be 100 mol%.

[0020] Whether the anode active material exhibits the perovskite-type crystal phase belonging to the space group I4 / mmm can be confirmed, for example, by performing an X-ray diffraction measurement (powder X-ray diffraction). In an X-ray diffraction measurement with a Cu-Kα emitter, the perovskite-type crystal phase belonging to the space group I4 / mmm preferably exhibits typical peaks at 2θ = 32.1°, 40.8°, 46.5°, 58.3°, and 68.6°. Each of these peaks can shift within a range of ± 0.8°. The range can be ± 0.5°, ± 0.3°, or ± 0.1°.

[0021] There are no particular restrictions on the shape of the anode active material, and examples can include a granular form. The average particle size (D 50The particle size of the anode active material is, for example, 50 nm or more and 50 µm or less. The average particle size can be obtained, for example, by observation using SEM. The number of samples is preferably large; for example, 100 or more.

[0022] The anode active material in the present disclosure is used for the lithium-ion battery described later. B. Method for producing the anode active material

[0023] Fig.Figure 1 is a flowchart illustrating an example of the process for producing the anode active material in the present disclosure. The process for producing the anode active material in the present disclosure comprises: a preparation step in which a raw material mixture is prepared, comprising a first metal element source containing an Sr element, a second metal element source containing an S element, and a third metal element source containing a metal element other than an Sr element and an S element; a precursor preparation step in which a precursor is obtained by mechanically grinding the raw material mixture; and a firing step in which the precursor is fired.

[0024] According to the present disclosure, the anode active material described above can be easily produced by mechanically grinding the raw material mixture containing the first metal element source, the second metal element source, and the third metal element source. This is because the use of the third metal element, which is other than an Sr element and an S element, facilitates the incorporation of S elements into the crystal structure and allows for an increase in the S element doping. 1. Manufacturing step

[0025] The manufacturing step described in the present disclosure is a step in which a raw material mixture is produced, comprising a first metal element source containing an Sr element, a second metal element source containing an S element, and a third metal element source containing a metal element other than an Sr element and an S element. The raw material mixture can be produced in-house or purchased from others.

[0026] The first metal element source contains an Sr element. Furthermore, the first metal element source can additionally contain at least one S element and one O element. The first metal element source can be the same material as a second metal element source. Examples of the Sr element source can include a simple substance made of Sr, SrS, and SrO. The first metal element source can be of only one type, or it can be of two or more types.

[0027] The second metal element source contains a sulfur element. Furthermore, the second metal element source can additionally contain at least one sulfur element and at least one sulfur element, as well as a third metal element source described later. The second metal element source can be the same material as the first metal element source. Furthermore, the second metal element source can be the same material as the third metal element source described later. Examples of the second metal element source can include a simple substance composed of sulfur, srS, and ZrS₂. The second metal element source can be of only one type, or it can be of two or more types.

[0028] The third metal element source contains a metal element other than an Sr element and an S element. The metal element (third metal element) is preferably the metal M described under "A. Anode Active Material". Furthermore, the third metal element source may additionally contain at least one of each of an Sr element, an S element, and an O element. The third metal element source may be the same material as the first and second metal element sources. Examples of the third metal element source include ZrS₂, Nb₂O₅, Fe₂O₃, TiO₂, MnO₂, and MoO₃. The third metal element source may be of only one type, or it may be of two or more types.

[0029] There are no special restrictions on the ratio of the first metal element source, the second metal element source and the third metal element source in the raw material mixture, provided that the ratio makes it possible to obtain the above-mentioned anode active material. 2. Precursor manufacturing step

[0030] The precursor manufacturing step in the present disclosure is a step in which a precursor is obtained by mechanically grinding the raw material mixture.

[0031] There are no particular restrictions on mechanical grinding, provided it is a process for mixing the raw material mixture using mechanical energy, and examples may include ball grinding, vibratory grinding, turbo grinding, mechanofusion, and disk grinding. Planetary ball grinding is particularly preferred. Furthermore, the mechanical grinding can be dry or wet.

[0032] The conditions for mechanical grinding are appropriately designed to obtain the desired anode-active material. For example, when planetary ball milling is used, the raw material mixture and the balls to be ground are placed in a container, and the processing is carried out at a specific rotational speed of the weighing table and for a specific duration. The rotational speed of the weighing table might be, for example, 200 rpm or more and 800 rpm or less. Furthermore, the processing time for planetary ball milling might be, for example, 30 minutes or more and 100 hours or less. Examples of container and ball materials to be used in planetary ball milling include ZrO₂ and Al₂O₃. The diameter of the balls to be ground might be, for example, 1 mm or more and 20 mm or less. 3rd firing step

[0033] The firing step in the present disclosure is a step in which the precursor is fired.

[0034] There are no specific restrictions on the firing temperature, as long as the anode active material can be obtained with the perovskite-type crystal phase, but it is, for example, 800°C or more and 1400°C or less, and can be 1000°C or more and 1200°C or less. There are also no specific restrictions on the firing duration, but it is, for example, 24 hours or more and 384 hours or less, and can be 48 hours or more and 192 hours or less. Firing can be carried out in a normal-pressure atmosphere, in a reduced-pressure atmosphere, and in an inert atmosphere, such as an argon atmosphere. 4. Anode active material

[0035] The anode active material obtained through the aforementioned steps is the same as that described above under “A. Anode active material”; therefore, further descriptions are omitted here. C. Lithium-ion battery

[0036] Fig. Figure 2 is a schematic cross-sectional view showing an example of a lithium-ion battery in the present disclosure. The Fig.The lithium-ion battery 10 shown in Figure 2 comprises a cathode active material layer (1), an anode active material layer (2) containing the anode active material, an electrolyte layer (3) formed between the cathode active material layer (1) and the anode active material layer (2), a cathode current collector (4) for collecting currents from the cathode active material layer (1), and an anode current collector (5) for collecting currents from the anode active material layer (2). The anode active material refers to the aforementioned anode active material in the present disclosure.

[0037] The lithium-ion battery in the present disclosure can be a lithium-ion battery with excellent capacity characteristics if the anode active material layer contains the specified anode active material. 1. Anode active material layer

[0038] The anode active material layer contains at least one anode active material. The anode active material is the same as that described above under “A. Anode Active Material”; therefore, further description is omitted here. In addition to the anode active material, the anode active material layer may contain at least one conductive material and one electrolyte, but it is preferred that it contains neither a conductive material nor an electrolyte. “Contains neither a conductive material nor an electrolyte” means that the total proportion of conductive material and electrolyte in the anode active material layer is 5 wt.% or less. The total proportion of conductive material and electrolyte may be 3 wt.% or less, 1 wt.% or less, or 0 wt.%.

[0039] Examples of the conductive material can include a carbon material. Examples of carbon materials can include particulate carbon materials such as acetylene black (AB) and Ketjen black (KB), and fibrous carbon materials such as carbon fibers, carbon nanotubes (CNTs), and carbon nanofibers (CNFs). The electrolyte is described later in "3. Electrolyte Layer".

[0040] The thickness of the anode active material layer is, for example, 0.1 µm or more and 1000 µm or less. 2. Cathode active material layer

[0041] The cathode active material layer contains at least one cathode active material and may, if required, include a conductive material and an electrolyte. Examples of cathode active materials include oxide active materials. Examples of oxide active materials include rock salt bed-type active materials such as LiCoO2, LiMnO2, LiNiO2, LiVO2, and LiNi. 1 / 3 Co1 / 3 Mn 1 / 3 O2, a spinel-type active material such as LiMn2O4, Li4Ti5O 12 and Li(Ni 0.5 Mn 1.5 The active material comprises O4 and an olivine-type active material such as LiFePO4, LiMnPO4, LiNiPO4, and LiCoPO4. The surface of the cathode active material can be coated with a lithium ion-conducting oxide. Examples of lithium ion-conducting oxides include LiNbO3. The conductive material and electrolyte are the same as described above.

[0042] The thickness of the cathode active material layer is, for example, 0.1 µm or more and 1000 µm or less. 3. Electrolyte layer

[0043] The electrolyte layer is a layer containing at least one electrolyte. The electrolyte can be a solid electrolyte, an electrolyte solution (liquid electrolyte), or a mixture thereof. Preferably, the electrolyte is a solid electrolyte. Examples of solid electrolytes include inorganic solid electrolytes such as sulfide solid electrolytes, oxide solid electrolytes, nitride solid electrolytes, and halide solid electrolytes, as well as organic polymer electrolytes such as polymer electrolytes. Among these, a sulfide solid electrolyte is particularly preferred.

[0044] The thickness of the electrolyte layer is, for example, 0.1 µm or more and 1000 µm or less. 4. Lithium-ion battery

[0045] The lithium-ion battery in the present disclosure can be a liquid-state battery, and it can be a solid-state battery, the latter being preferred. The term "solid-state battery" in the present disclosure refers to a lithium-ion battery in which the aforementioned electrolyte layer is a solid electrolyte layer containing a solid electrolyte. Furthermore, the lithium-ion battery in the present disclosure can be a primary battery, and it can be a secondary battery, preferably a secondary battery. The reason for this is that it can be repeatedly charged and discharged and is suitable, for example, as a battery for installation in a car. Furthermore, examples of the battery's shape can include a coin shape, a laminate shape, a cylindrical shape, and a square shape.

[0046] Furthermore, the present disclosure is not limited to the embodiments. The embodiments are exemplary, and any other variations are to be included in the technical scope of the present disclosure, provided they have essentially the same characteristics as the technical idea described in the claims of the present disclosure and have a similar function and effect. Examples [Example 1]<Synthese von Anodenaktivmaterial>

[0047] The raw materials, weighed out as follows: 0.43085 g SrS, 0.31897 g Nb₂O₅, 0.38326 g Fe₂O₃, 0.0958 g TiO₂, and 0.07696 g S, were mixed in a mortar. The mixture was then milled for one hour at 300 rpm using planetary ball milling with 5 mm diameter (ϕ) zirconium dioxide spheres. The mixed raw material was formed into a pellet using a hydraulic press and fired under vacuum. The temperature rise rate was 0.7°C / min, the firing temperature was 1000°C, and the firing duration was 96 hours in a quartz glass atmosphere. The material was cooled naturally. In this way, an anode-active material (Sr) was produced. 1.2 Note 0.8 Fe 1.6 Ti 0.4 O 5.2 S2). An XRD measurement of the obtained anode active material confirmed the perovskite structure of space group I4 / mmm. The result of the XRD measurement is in Fig.3 is illustrated with the comparative example 1 described later. <Herstellung der Batterie>

[0048] 100 mg of a sulfide solid electrolyte were weighed out, filled into a cylinder of 11.28 mm diameter (ϕ) and compressed using a uniaxial press under a pressure of 1 t / cm² 2 pressed. In this way, a separator was produced. Subsequently, 8 mg of the synthesized anode active material (Sr) were added. 1.2 Note 0.8 Fe 1.6 Ti 0.4 O 5.2 S2) weighed, filled into a cylinder and pressed with a uniaxial press under a pressure of 6 t / cm² 2 Pressed to form a working electrode. Metallic lithium was used as the counter electrode and pressed with a uniaxial press under a pressure of 0.5 t / cm². 2 Pressed. Stainless steel (SUS) pins were inserted at both ends and clamped under a pressure of 20 kg to produce an evaluation cell (battery). [Example 2]

[0049] An anode active material was synthesized by substituting the raw materials for 0.31089 g SrO, 0.46606 g ZrS₂, 0.38326 g Fe₂O₃, and 0.0958 g TiO₂. A battery was fabricated in the same manner as in Example 1, except for the substitution. Furthermore, although the proportion of oxygen elements in the anode active material of Example 2 was not clearly specified due to the charge compensation relationship, the composition was given as SrZrFe 1.6 Ti 0.4 O 4.2+x S2 (0≤x≤1) is assumed, as the perovskite-type crystal phase has been confirmed. [Example 3]

[0050] An anode active material (SrMnFe 1.6 Ti 0.4 O 5.2 S2) was synthesized by substituting the raw materials for 0.35904 g SrS, 0.26082 g MnO2, 0.38326 g Fe2O3, 0.0958 g TiO2, and 0.0962 g S. A battery was manufactured in the same manner as in Example 1, except for the substitution. [Example 4]

[0051] An anode active material (Sr 1.1 Sn 0.8 Fe 1.8 Ti 0.4 O 5.1 S2) was synthesized by substituting the raw materials for 0.35904 g SrS, 0.31897 g SnO2, 0.38326 g Fe2O3, 0.0958 g TiO2, and 0.07696 g S. A battery was manufactured in the same manner as in Example 1, except for the substitution. [Example 5]

[0052] An anode active material (Sr 1.3 Mon 0.7 Fe 1.6 Ti 0.4 O 5.2 S2) was synthesized by substituting the raw materials for 0.46675 g SrS, 0.30227 g MoO3, 0.38326 g Fe2O3, 0.0958 g TiO2, and 0.06734 g S. A battery was manufactured in the same manner as in Example 1, except for the substitution. [Comparison example 1]

[0053] The raw materials used were 1.476 g SrCO3, 0.639 g Fe2O3, and 0.160 g TiO2. The materials were mixed in a mortar, formed into a pellet using a hydraulic press, and fired under conditions of a temperature increase rate of 0.7°C / min, a firing temperature of 1000°C, a firing duration of 96 hours, and in an atmospheric environment. The material was cooled naturally. In this way, an anode-active material (SrFe) was produced. 0.8 Ti 0.2 O3) synthesized. A battery was manufactured in the same way as in Example 1, except for the points mentioned above. [Comparative example 2]

[0054] The raw materials used were 570 mg of the SrFe produced in comparative example 1. 0.8 Ti 0.2O3 and 19 mg S were used. The materials were mixed in a mortar, formed into a pellet using a hydraulic press, and fired under vacuum. The temperature rise rate was 0.7°C / min, the firing temperature was 1000°C, and the firing duration was 96 hours, all within a quartz glass atmosphere. The temperature drop rate was achieved through natural cooling. In this way, an anode-active material (Sr2Fe) was produced. 1.6 Ti 0.4 O 5.6 S 0.2 ) synthesized. A battery was manufactured in the same way as in Example 1, except for the points mentioned above. [Comparative example 3]

[0055] The commercial product Li4Ti5O was used as the anode active material. 12 used. A battery was manufactured in the same way as in Example 1, except for the replacement. [Evaluation]

[0056] The battery characteristics were evaluated for each of the batteries obtained in Examples 1 to 5 and Comparison Examples 1 to 3 as follows. The evaluation cell was placed in a charge and discharge unit (HJ-SD8 from HOKUTO DENKO CORPORATION), and the rate characteristics (reversible capacity) were evaluated in the voltage range of 1.0 to 2.5 V and at a current of 0.1 mA / cm². 2 , 0.5 mA / cm 2 , 1 mA / cm 2 and 2 mA / cm 2 Cycle evaluations were also carried out at a current value of 0.5 mA / cm². 2 The test was performed 10 times, and the capacity maintenance rate after 10 cycles was calculated. The results are shown in Table 1. Furthermore, the charging and discharging curves of Example 1 for each current value are shown in Table 1. Fig. 4 is shown. Furthermore, the capacities of examples 1 to 5 and of comparison example 1 are shown in Fig. 5 plotted per current value. [Table 1] Composition of the anode active material Reversible capacity (mAh / g) Capacity maintenance rate 0,1mA / cm 2 0,5mA / cm 2 1mA / cm 2 2mA / cm 2 Example 1 Sr 1.2 Nb 0.5 Fe 1.6 Ti 0.4 O 5.2 S2 184 156 145 133 97 Example 2 SrZrFe 1.6 Ti 0.4 O 4.2+x S2 145 121 114 106 97 Example 3 SrMnFe 1.6 Ti 0.4 O 5.2 S2 19 13 11 10 95 Example 4 Sr 1.1 Sn 0.8 Fe 1.8 Ti 0.4 O 5.1 S2 156 112 102 91 96 Example 5 Mr. 1.3 Know 0.7 Want 1.6 Of 0.40 SHE 5.2 S2 146 106 97 83 96 Comparative example 1 SrFe 0.8 You 0.2 O3 10 7 1 1 - Comparative example 2 Sr2Fe 1.6 Of 0.4 SHE 5.6 SHE 0.2 7 6 1 1 - Comparative example 3 Li4Ti5O 12 0.0001 - - - -

[0057] From the in Fig. In the three XRD patterns shown, the peaks derived from the perovskite structure at positions near 2θ = 32.1°, 40.8°, 46.5°, 58.3°, and 68.6° were confirmed in both Example 1 and Comparison Example 1. It was confirmed that the anode active material of Comparison Example 1 exhibited only a perovskite structure, as it contained no impurities. Conversely, it was confirmed that Example 1 had a perovskite structure of space group I4 / mmm as a major phase, although some impurities were present.

[0058] Furthermore, the following was extracted from the in Fig. The four charging and discharging curves shown confirmed that the battery in Example 1 had a flat voltage range at approximately 1.5 V and that the battery functioned well. Furthermore, the plot of the rate characteristics of each example and comparison example, which are shown in Table 1 and Fig.Figure 5 confirms that excellent battery capacities were obtained in Examples 1 to 5. Incidentally, comparison examples 2 and 3 could not even be charged or discharged at the low rate, so plotting was not possible. These results show that the batteries of Examples 1 to 5 were charged and discharged well even when the anode active material layer contained neither a conductive material nor an electrolyte, and that the anode active material in the present disclosure exhibits excellent ionic and electronic conductivity.

[0059] The reasons why the anode active material of Examples 1 to 5 exhibits excellent ionic and electronic conductivity are uncertain, but are likely the following. The anode active material of Comparative Example 1 was black and therefore presumably had electronic conductivity if the perovskite structure contained a sr element. However, it is suggested that battery activity did not occur without electrolyte because there was no ionic conductivity. It is hypothesized that the addition of excess s to such a state allowed the lithium ions to "jump" onto the sr sites, thus enabling ionic conductivity.

[0060] Incidentally, impurities remained high when the S doping was increased compared to Example 2 without changing the amount of the third metal. Therefore, it has been suggested that the proportion of the third metal should preferably be greater when the S doping is increased, as shown in Examples 1 to 5. Reference symbol list 1 Cathode active material layer 2 Anode active material layer 3 Electrolyte layer 4 Cathode current collector 5 Anode current collector 10 Lithium-ion batteries

Claims

[1] Lithium-ion battery (10) comprising a cathode active material layer (1) containing a cathode active material, an anode active material layer (2) containing an anode active material, and an electrolyte layer (3) formed between the cathode active material layer (1) and the anode active material layer (2), characterized by , that The anode active material comprises: at least one Sr element and one S element; and a perovskite-type crystal phase belonging to a space group of I4 / mmm; and a molar ratio of the S element to the Sr element is greater than 0.

1. [2] Lithium-ion battery (10) according to claim 1, characterized by , that the lithium-ion battery (10) is a solid-state lithium-ion battery. [3] Lithium-ion battery (10) according to claim 2, characterized by , that the anode active material layer (2) contains neither a conductive material nor a solid electrolyte.

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