Batteries and solid-state batteries
By integrating sulfide solid electrolytes and odorants within defined mass ratios in battery layers, the safety and performance of halide-based batteries are improved through early leak detection and reduced fire risk.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
- Filing Date
- 2022-05-24
- Publication Date
- 2026-05-13
AI Technical Summary
Conventional batteries using halide solid electrolytes face challenges in detecting electrolyte leakage due to their odorlessness, while sulfide solid electrolytes, although easier to detect, pose safety risks under specific conditions.
Incorporating a trace amount of sulfide solid electrolyte and an odorant into the battery layers, ensuring the mass ratios of sulfide solid electrolyte and odorant within specific limits, allowing early detection of leaks through odor generation.
Enhances battery safety by enabling early detection of leaks, maintaining performance, and improving flame retardancy while minimizing performance degradation.
Smart Images
Figure 0007857584000001 
Figure 0007857584000002
Abstract
Description
[Technical Field]
[0001] This disclosure relates to batteries and solid-state batteries. [Background technology]
[0002] Patent Document 1 discloses a battery that uses a compound containing indium as a cation and a halogen element as an anion as a solid electrolyte. [Prior art documents] [Patent Documents]
[0003] [Patent Document 1] Japanese Patent Publication No. 2006-244734 [Patent Document 2] International Publication No. 2007 / 004590 [Overview of the Initiative]
[0004] In conventional technology, further improvements in battery safety are desirable.
[0005] In one aspect of this disclosure, the battery is The device comprises a positive electrode active material layer, a negative electrode active material layer, and a solid electrolyte layer located between the positive electrode active material layer and the negative electrode active material layer. The following requirements (i) or (ii) must be met. (i) At least one layer selected from the group consisting of the positive electrode active material layer, the negative electrode active material layer, and the solid electrolyte layer comprises a halide solid electrolyte and a sulfide solid electrolyte, The ratio of the mass of the sulfide solid electrolyte to the total mass of the positive electrode active material layer, the negative electrode active material layer, and the solid electrolyte layer is 25% or less. (ii) At least one layer selected from the group consisting of the positive electrode active material layer, the negative electrode active material layer, and the solid electrolyte layer comprises a halogenated solid electrolyte and an odorant, The ratio of the mass of the odorant to the total mass of the positive electrode active material layer, the negative electrode active material layer, and the solid electrolyte layer is 1% or less.
[0006] According to the present disclosure, the safety of the battery can be further improved.
Brief Description of the Drawings
[0007] [Figure 1] FIG. 1 is a cross-sectional view showing a schematic configuration of a battery in Embodiment 1. [Figure 2] FIG. 2 is a cross-sectional view showing a schematic configuration of a solid battery in Embodiment 2.
Modes for Carrying Out the Invention
[0008] (Findings on which the present disclosure is based) According to recent research, sulfide solid electrolytes may burn under specific conditions. Sulfide solid electrolytes may react with moisture in the air to generate hydrogen sulfide. However, since hydrogen sulfide can be easily detected, there is an advantage that leakage of the contents can be easily detected when the battery container is damaged or deteriorated.
[0009] Halide solid electrolytes are difficult to burn even under the above specific conditions. Therefore, a battery using a halide solid electrolyte as the solid electrolyte is more excellent in safety than a battery using a sulfide solid electrolyte. However, since halide solid electrolytes are odorless, there is a problem that it is difficult to detect leakage of the contents when the battery container is damaged or deteriorated.
[0010] The present inventor has intensively studied a method for further improving the safety of a battery using a halide solid electrolyte. As a result, it has been discovered that electrolyte leakage can be detected early by adding a trace amount of an odorant such as a sulfide solid electrolyte.
[0011] (Outline of one aspect according to the present disclosure) The battery according to the first aspect of the present disclosure is It includes a positive electrode active material layer, a negative electrode active material layer, and a solid electrolyte layer positioned between the positive electrode active material layer and the negative electrode active material layer. It satisfies the following requirement (i) or (ii). (i) At least one layer selected from the group consisting of the positive electrode active material layer, the negative electrode active material layer, and the solid electrolyte layer contains a halide solid electrolyte and a sulfide solid electrolyte. The ratio of the mass of the sulfide solid electrolyte to the total mass of the positive electrode active material layer, the negative electrode active material layer, and the solid electrolyte layer is 25% or less. (ii) At least one layer selected from the group consisting of the positive electrode active material layer, the negative electrode active material layer, and the solid electrolyte layer contains a halide solid electrolyte and an odorant. The ratio of the mass of the odorant to the total mass of the positive electrode active material layer, the negative electrode active material layer, and the solid electrolyte layer is 1% or less.
[0012] According to the above configuration, leakage of electrolytes and the like can be detected early by odorants such as sulfide solid electrolytes. For example, when the battery contains a sulfide solid electrolyte, if the sulfide solid electrolyte leaks outside the battery, the sulfide solid electrolyte reacts with moisture in the air to generate hydrogen sulfide. Since hydrogen sulfide has a rotten egg odor, the leakage can be easily detected by the odor. Therefore, the safety of the battery can be improved.
[0013] In a second aspect of the present disclosure, for example, in the battery according to the first aspect, in the requirement (i), the ratio of the mass of the sulfide solid electrolyte to the total mass of the positive electrode active material layer, the negative electrode active material layer, and the solid electrolyte layer may be 5% or less. According to the above configuration, the safety of the battery can be improved.
[0014] In a third aspect of the present disclosure, for example, in the battery according to the second aspect, in the requirement (i), the ratio of the mass of the sulfide solid electrolyte to the total mass of the positive electrode active material layer, the negative electrode active material layer, and the solid electrolyte layer may be 1% or less. According to the above configuration, the safety of the battery can be improved.
[0015] In a fourth aspect of this disclosure, for example, in a battery according to the second aspect, in requirement (i), the ratio of the mass of the sulfide solid electrolyte to the total mass of the positive electrode active material layer, the negative electrode active material layer, and the solid electrolyte layer may be 0.1% or less. With the above configuration, the safety of the battery can be improved.
[0016] In a fifth aspect of this disclosure, for example, in a battery according to the second aspect, in requirement (i), the ratio of the mass of the sulfide solid electrolyte to the total mass of the positive electrode active material layer, the negative electrode active material layer, and the solid electrolyte layer may be 0.01% or less. With the above configuration, the safety of the battery can be improved.
[0017] In a sixth aspect of this disclosure, for example, in a battery according to any one of the first to fifth aspects, in requirement (i), the sulfide solid electrolyte is Li2S-P2S5, Li2S-SiS2, Li2S-B2S3, Li2S-GeS2, Li 3.25 Ge 0.25 P 0.75 S4, and Li 10 GeP2S 12 It may include at least one selected from the group consisting of the above. With the above configuration, the ionic conductivity of the sulfide solid electrolyte can be improved.
[0018] In a seventh aspect of this disclosure, for example, in the battery according to the first aspect, in requirement (ii), the odor substance may be a substance that does not have lithium-ion conductivity. With the above configuration, the safety of the battery can be improved.
[0019] In the eighth aspect of this disclosure, for example, in a battery according to any one of the first to seventh aspects, the halide solid electrolyte may include Li, at least one selected from the group consisting of metal elements other than Li and metalloid elements, and at least one selected from the group consisting of F, Cl, Br, and I. With the above configuration, the ionic conductivity of the halide solid electrolyte can be improved.
[0020] In a ninth aspect of this disclosure, for example, in the battery according to the eighth aspect, the halogen solid electrolyte may be represented by the following compositional formula (1). L α M β X γ ...Equation (1) α, β, and γ are each greater than 0. M is at least one selected from the group consisting of metal elements other than Li and metalloid elements. X is at least one selected from the group consisting of F, Cl, Br, and I. With the above configuration, the ionic conductivity of the halide solid electrolyte can be further improved.
[0021] In the tenth aspect of this disclosure, for example, in the battery according to the ninth aspect, M in the composition formula (1) may contain yttrium. With the above configuration, the ionic conductivity of the halide solid electrolyte can be further improved.
[0022] The solid battery relating to the 11th aspect of this disclosure is An exterior body having an internal space, The power generation element arranged in the aforementioned internal space, In the aforementioned internal space, an odorous substance is placed outside the power generation element, It is equipped with.
[0023] With the above configuration, odor-emitting substances can be used to detect leaks of, for example, electrolytes from power generation elements at an early stage. This improves the safety of solid-state batteries.
[0024] In a twelfth aspect of this disclosure, for example, in a solid-state battery according to the eleventh aspect, the odor substance may be solid.
[0025] In a thirteenth aspect of this disclosure, for example, in a solid-state battery according to the eleventh or twelfth aspect, the odorous substance may include a sulfide solid electrolyte. The sulfide solid electrolyte has the function of improving the output characteristics of the solid-state battery. Therefore, with the above configuration, the deterioration of the solid-state battery's performance due to the addition of the odorous substance is suppressed. Thus, it is possible to improve the safety of the solid-state battery while maintaining its performance.
[0026] In a 14th aspect of this disclosure, for example, a solid-state battery according to any one of the 11th to 13th aspects may further include a first current collector positioned above the power generation element and a second current collector positioned below the power generation element, and the odorant may be positioned above the first current collector. With this configuration, the odorant is less likely to adversely affect the characteristics of the solid-state battery.
[0027] Embodiments of the present disclosure will be described below with reference to the drawings.
[0028] (Embodiment 1) Figure 1 is a cross-sectional view showing the schematic configuration of the battery 10 in Embodiment 1.
[0029] The battery 10 comprises a positive electrode active material layer 101, a negative electrode active material layer 103, and a solid electrolyte layer 102 located between the positive electrode active material layer 101 and the negative electrode active material layer 103. The battery 10 satisfies either requirement (i) or (ii) below. (i) At least one layer selected from the group consisting of a positive electrode active material layer 101, a negative electrode active material layer 103, and a solid electrolyte layer 102 contains a halide solid electrolyte 201 and a sulfide solid electrolyte 202. The ratio of the mass of the sulfide solid electrolyte 202 to the total mass of the positive electrode active material layer 101, the negative electrode active material layer 103, and the solid electrolyte layer 102 is 25% or less. (ii) At least one layer selected from the group consisting of a positive electrode active material layer 101, a negative electrode active material layer 103, and a solid electrolyte layer 102 contains a halogenated solid electrolyte 201 and an odorant. The ratio of the mass of the odorant to the total mass of the positive electrode active material layer 101, the negative electrode active material layer 103, and the solid electrolyte layer 102 is 1% or less.
[0030] In this disclosure, “odor” means an odor that can be perceived by the human sense of smell or detected by a detection element. “Odorous substance” includes substances that have an odor themselves, and substances that, when leaked outside the battery 10, react with moisture in the air to produce an odor. An example of the former is sulfur dioxide. An example of the latter is the sulfide solid electrolyte 202. “Odorous substance” may be a low molecular weight compound containing a sulfur atom, or a nitrogen compound such as ammonia and trimethylamine.
[0031] With the above configuration, leakage of electrolytes, etc., can be detected early by odorous substances such as sulfide solid electrolyte 202. For example, if the battery 10 contains sulfide solid electrolyte 202 as an odorous substance, when the sulfide solid electrolyte 202 leaks to the outside of the battery 10, it reacts with moisture in the air to generate hydrogen sulfide. Since hydrogen sulfide has a rotten egg odor, the leak can be easily detected by its smell. If a leak is detected, charging or discharging of the battery 10 can be stopped immediately, and the malfunction can be notified to the outside. Therefore, the safety of the battery 10 can be improved. Figure 1 illustrates a case where the solid electrolyte layer 102 contains a halogen solid electrolyte 201 and a sulfide solid electrolyte 202.
[0032] It is predicted that adding odorous substances to a battery will decrease its performance as the amount added increases. However, sulfide solid electrolytes have high ionic conductivity and therefore improve the output characteristics of the battery. For this reason, if requirement (i) above is met, the decrease in battery performance due to the addition of sulfide solid electrolyte is suppressed. Thus, it is possible to improve the safety of battery 10 while maintaining its performance. Furthermore, if requirement (ii) above is met, the proportion of odorous substances is small, so it is possible to improve the safety of battery 10 while suppressing the decrease in battery performance.
[0033] The ratio of the mass of the sulfide solid electrolyte 202 to the total mass of the positive electrode active material layer 101, the negative electrode active material layer 103, and the solid electrolyte layer 102 can be calculated, for example, by the following method: Extract the outline of the sulfide solid electrolyte 202 from SEM images of the cross-sections of the positive electrode active material layer 101, the negative electrode active material layer 103, and the solid electrolyte layer 102, and calculate its area. Next, calculate the radius of a circle having an area equivalent to this area (equivalent circle diameter). Assuming that the sulfide solid electrolyte 202 is a perfect sphere with the calculated equivalent circle diameter, the volume of the sulfide solid electrolyte 202 can be calculated from the equivalent circle diameter. Similarly, calculate the volume of each of the multiple sulfide solid electrolytes 202 contained in the positive electrode active material layer 101, the negative electrode active material layer 103, and the solid electrolyte layer 102 using the same method. The sum of the obtained values represents the total volume of sulfide solid electrolyte 202 contained in the positive electrode active material layer 101, the negative electrode active material layer 103, and the solid electrolyte layer 102. The density of the sulfide solid electrolyte 202 can be determined from literature, etc. From these values, the ratio of the mass of sulfide solid electrolyte 202 to the total mass of the positive electrode active material layer 101, the negative electrode active material layer 103, and the solid electrolyte layer 102 can be calculated.
[0034] The ratio of the mass of odorous substances to the total mass of the positive electrode active material layer 101, the negative electrode active material layer 103, and the solid electrolyte layer 102 can be calculated, for example, by the following method. Odorous substances contained in the positive electrode active material layer 101, the negative electrode active material layer 103, and the solid electrolyte layer 102 can be removed, for example, by dissolving the solid electrolyte contained in these layers using a solvent, and then removing the positive electrode active material and the negative electrode active material. The total mass of the positive electrode active material layer 101, the negative electrode active material layer 103, and the solid electrolyte layer 102, and the mass of the odorous substances can be determined from the masses before and after the above removal. From these values, the ratio of the mass of odorous substances to the total mass of the positive electrode active material layer 101, the negative electrode active material layer 103, and the solid electrolyte layer 102 can be calculated. Furthermore, the ratio of the mass of odorous substances to the total mass of the negative electrode active material layer 103 and the solid electrolyte layer 102 can also be obtained by infrared spectroscopy (FT-IR analysis) or gas chromatography-mass spectrometry (GC-MS analysis).
[0035] In requirement (i) above, the ratio of the mass of the sulfide solid electrolyte 202 to the total mass of the positive electrode active material layer 101, the negative electrode active material layer 103, and the solid electrolyte layer 102 may be 5% or less. Reducing the ratio of the sulfide solid electrolyte 202 can further enhance the flame retardancy of the battery 10. This can improve the safety of the battery 10.
[0036] In requirement (i) above, the ratio of the mass of the sulfide solid electrolyte 202 to the total mass of the positive electrode active material layer 101, the negative electrode active material layer 103, and the solid electrolyte layer 102 may be 1% or less. Reducing the ratio of the sulfide solid electrolyte 202 can further enhance the flame retardancy of the battery 10. This can improve the safety of the battery 10.
[0037] In requirement (i) above, the ratio of the mass of the sulfide solid electrolyte 202 to the total mass of the positive electrode active material layer 101, the negative electrode active material layer 103, and the solid electrolyte layer 102 may be 0.1% or less. Reducing the ratio of the sulfide solid electrolyte 202 can further enhance the flame retardancy of the battery 10. This can improve the safety of the battery 10.
[0038] In requirement (i) above, the ratio of the mass of the sulfide solid electrolyte 202 to the total mass of the positive electrode active material layer 101, the negative electrode active material layer 103, and the solid electrolyte layer 102 may be 0.01% or less. Reducing the ratio of the sulfide solid electrolyte 202 can further enhance the flame retardancy of the battery 10. This can improve the safety of the battery 10.
[0039] In requirement (i) above, there is no particular lower limit to the ratio of the mass of the sulfide solid electrolyte 202 to the total mass of the positive electrode active material layer 101, the negative electrode active material layer 103, and the solid electrolyte layer 102. The lower limit is, for example, 0.001%.
[0040] In requirement (ii) above, there is no particular limit to the ratio of the mass of odorous substances to the total mass of the positive electrode active material layer 101, the negative electrode active material layer 103, and the solid electrolyte layer 102. The lower limit is, for example, 0.001%.
[0041] Any one of the positive electrode active material layer 101, the negative electrode active material layer 103, and the solid electrolyte layer 102 may contain a halide solid electrolyte 201 and a sulfide solid electrolyte 202. All of the positive electrode active material layer 101, the negative electrode active material layer 103, and the solid electrolyte layer 102 may contain a halide solid electrolyte 201 and a sulfide solid electrolyte 202. Any two layers selected from the group consisting of the positive electrode active material layer 101, the negative electrode active material layer 103, and the solid electrolyte layer 102 may contain a halide solid electrolyte 201 and a sulfide solid electrolyte 202.
[0042] Any one of the positive electrode active material layer 101, the negative electrode active material layer 103, and the solid electrolyte layer 102 may contain the halide solid electrolyte 201 and the odorant. All of the positive electrode active material layer 101, the negative electrode active material layer 103, and the solid electrolyte layer 102 may contain the halide solid electrolyte 201 and the odorant. Any two layers selected from the group consisting of the positive electrode active material layer 101, the negative electrode active material layer 103, and the solid electrolyte layer 102 may contain the halide solid electrolyte 201 and the odorant.
[0043] As illustrated in FIG. 1, the solid electrolyte layer 102 may contain the halide solid electrolyte 201 and the sulfide solid electrolyte 202. According to the above configuration, the safety of the battery 10 can be further improved while maintaining the performance of the battery 10.
[0044] In the above requirement (i), the sulfide solid electrolyte 202 may be a solid electrolyte having lithium ion conductivity. When the sulfide solid electrolyte 202 is a solid electrolyte having lithium ion conductivity, examples of the sulfide solid electrolyte 202 include a composition composed of lithium sulfide (Li2S) and phosphorus pentasulfide (P2S5).
[0045] In the above requirement (i), the sulfide solid electrolyte 202 may contain at least one selected from the group consisting of Li2S-P2S5, Li2S-SiS2, Li2S-B2S3, Li2S-GeS2, Li 3.25 Ge 0.25 P 0.75 S4, and Li 10 GeP2S 12 According to the above configuration, the ionic conductivity of the sulfide solid electrolyte 202 can be improved.
[0046] Further, at least one selected from the group consisting of Li3N, LiCl, LiBr, Li3PO4, and Li4SiO4 may be added to the above sulfide solid electrolyte 202 as an additive.
[0047] In requirement (ii) above, the odorous substance may be a substance that does not have lithium-ion conductivity. With the above configuration, the safety of the battery 10 can be improved.
[0048] When the odorant is a substance that does not conduct lithium ions, examples of odorants include sulfur dioxide, low molecular weight mercaptans, dialkyl sulfides, dialkyl disulfides, and mixtures thereof. Examples of low molecular weight mercaptans include methyl mercaptan, ethyl mercaptan, isopropyl mercaptan, isobutyl mercaptan, and tert-butyl mercaptan. Nitrogen compounds such as ammonia and trimethylamine are also odorants that do not conduct lithium ions.
[0049] The odor-causing substances may be encapsulated in microcapsules. The microcapsules may be configured to decompose thermally when the ambient temperature exceeds a certain temperature. This certain temperature may be, for example, 100°C.
[0050] The halide solid electrolyte 201 may be a material having lithium ion conductivity. The halide solid electrolyte 201 may contain Li, at least one selected from the group consisting of metal elements and metalloid elements other than Li, and at least one selected from the group consisting of F, Cl, Br, and I. With the above configuration, the ionic conductivity of the halide solid electrolyte 201 can be improved.
[0051] In this disclosure, “metalloid elements” refers to B, Si, Ge, As, Sb, and Te. “Metallic elements” refers to all elements in groups 1 through 12 of the periodic table, excluding hydrogen, and all elements in groups 13 through 16 of the periodic table, excluding B, Si, Ge, As, Sb, Te, C, N, P, O, S, and Se. In other words, “metalloid elements” or “metallic elements” are the group of elements that can become cations when forming inorganic compounds with halogen elements.
[0052] The halogenated solid electrolyte 201 may be made of a sulfur-free material. If the halogenated solid electrolyte 201 is sulfur-free, the generation of hydrogen sulfide gas can be suppressed.
[0053] The halide solid electrolyte 201 may also be represented by the following compositional formula (1).
[0054] Li α M β X γ ...Equation (1)
[0055] Here, α, β, and γ are each independently greater than 0. M is at least one selected from the group consisting of metallic elements and metalloid elements other than Li. X is at least one selected from the group consisting of F, Cl, Br, and I.
[0056] The halide solid electrolyte 201 represented by compositional formula (1) has higher ionic conductivity compared to halide solid electrolytes such as LiI, which consists of Li and halogen elements. Therefore, the halide solid electrolyte 201 represented by compositional formula (1) can be used to further improve the ionic conductivity of the halide solid electrolyte 201.
[0057] In compositional formula (1), M may contain Y (= yttrium). That is, the halide solid electrolyte 201 may contain Y as a metallic element. With the above configuration, the ionic conductivity of the halide solid electrolyte 201 can be further improved.
[0058] A solid halogen electrolyte containing Y is, for example, Li a Me b Y c The compound may be represented by the empirical formula X6, where a+mb+3c=6 and c>0. Me is at least one selected from the group consisting of metallic and metalloid elements excluding Li and Y. m is the valence of element Me. X is at least one selected from the group consisting of F, Cl, Br, and I.
[0059] Me may be, for example, at least one selected from the group consisting of Mg, Ca, Sr, Ba, Zn, Sc, Al, Ga, Bi, Zr, Hf, Ti, Sn, Ta, and Nb.
[0060] With the above configuration, the ionic conductivity of the halide solid electrolyte 201 can be further improved.
[0061] Examples of the halide solid electrolyte 201 include Li3YX6, Li2MgX4, Li2FeX4, Li(Al,Ga,In)X4, and Li3(Al,Ga,In)X6. Here, X is at least one selected from the group consisting of F, Cl, Br, and I.
[0062] In this disclosure, the notation "(A,B,C)" in chemical formulas means "at least one selected from the group consisting of A, B, and C." For example, "(Al,Ga,In)" is synonymous with "at least one selected from the group consisting of Al, Ga, and In." The same applies to other elements.
[0063] As a solid halogen electrolyte 201 containing Y, more specifically, for example, Li3YF6, Li3YCl6, Li3YBr6, Li3YI6, Li3YBrCl5, Li3YBr3Cl3, Li3YBr5Cl, Li3YBr5I, Li3YBr3I3, Li3YBrI5, Li3YClI5, Li3YCl3I3, Li3YCl5I, Li3YBr2Cl2I2, Li3YBrCl4I, Li 2.7 Y 1.1 Cl6, Li 2.5 Y 0.5 Zr 0.5 Cl6 and Li 2.5 Y 0.3 Zr 0.7 Examples include Cl6.
[0064] The shape of the sulfide solid electrolyte 202 is not particularly limited. The shape of the sulfide solid electrolyte 202 may be, for example, needle-shaped, spherical, or ellipsoidal. For example, the shape of the sulfide solid electrolyte 202 may be particulate.
[0065] The shape of the odor substance is not particularly limited. The shape of the odor substance may be, for example, needle-shaped, spherical, or ellipsoidal. For example, the shape of the odor substance may be particulate. When the odor substance is encapsulated in microcapsules, the shape of the odor substance may be, for example, gel-like or liquid-like.
[0066] The shape of the halide solid electrolyte 201 is not particularly limited. The shape of the halide solid electrolyte 201 may be, for example, needle-shaped, spherical, or ellipsoidal. For example, the shape of the halide solid electrolyte 201 may be particulate.
[0067] The solid electrolyte layer 102 is a layer containing a solid electrolyte. Known materials such as lithium-ion conductive solid electrolytes, sodium-ion conductive solid electrolytes, and magnesium-ion conductive solid electrolytes can be used as the solid electrolyte contained in the solid electrolyte layer 102.
[0068] The solid electrolyte layer 102 may contain a solid electrolyte having lithium ion conductivity.
[0069] As the solid electrolyte contained in the solid electrolyte layer 102, for example, sulfide solid electrolytes, halide solid electrolytes, and oxide solid electrolytes can be used.
[0070] As the sulfide solid electrolyte, the sulfide solid electrolyte 202 described above can be used.
[0071] As the halide solid electrolyte, the halide solid electrolyte 201 described above can be used.
[0072] Examples of oxide solid electrolytes include NASICON-type solid electrolytes represented by LiTi2(PO4)3 and its elemental substitutions, (LaLi)TiO3-based perovskite-type solid electrolytes, and Li 14 ZnGe4O 16 , LiSICON-type solid electrolytes such as Li4SiO4, LiGeO4 and their elemental substitutions, Li7La3Zr2O 12 Examples include garnet-type solid electrolytes represented by their elemental substitutions, Li3N and its H-substituted derivatives, Li3PO4 and its N-substituted derivatives, and glass or glass ceramics in which materials such as Li2SO4 and Li2CO3 are added to a base material containing Li-BO compounds such as LiBO2 and Li3BO3.
[0073] The thickness of the solid electrolyte layer 102 may be 5 μm or more and 150 μm or less. When the thickness of the solid electrolyte layer 102 is 5 μm or more, short circuits between the positive electrode active material layer 101 and the negative electrode active material layer 103 become less likely. When the thickness of the solid electrolyte layer 102 is 150 μm or less, the battery 10 can operate at high output.
[0074] The positive electrode active material layer 101 is a layer containing the positive electrode active material. The positive electrode active material layer 101 may also contain a solid electrolyte. As the solid electrolyte, the solid electrolyte described for the solid electrolyte layer 102 can be used.
[0075] As the positive electrode active material, a material having the property of intercalating and releasing lithium ions, sodium ions, or magnesium ions may be used.
[0076] When the positive electrode active material is a material that has the property of intercalating and releasing lithium ions, examples of positive electrode active materials that can be used include lithium cobalt oxide composite oxide (LCO), lithium nickel oxide composite oxide (LNO), lithium manganese oxide composite oxide (LMO), lithium-manganese-nickel oxide composite oxide (LMNO), lithium-manganese-cobalt oxide composite oxide (LMCO), lithium-nickel-cobalt oxide composite oxide (LNCO), and lithium-nickel-manganese-cobalt oxide composite oxide (LNMCO).
[0077] The shape of the positive electrode active material is not particularly limited. The shape of the positive electrode active material may be, for example, needle-shaped, spherical, or ellipsoidal. For example, the shape of the positive electrode active material may be particulate.
[0078] The thickness of the positive electrode active material layer 101 may be 5 μm or more and 150 μm or less. When the thickness of the positive electrode active material layer 101 is 5 μm or more, a sufficient energy density of the battery 10 can be ensured. When the thickness of the positive electrode active material layer 101 is 150 μm or less, the battery 10 can operate at high power.
[0079] The negative electrode active material layer 103 is a layer containing the negative electrode active material. The negative electrode active material layer 103 may also contain a solid electrolyte. As the solid electrolyte, the solid electrolyte described for the solid electrolyte layer 102 can be used.
[0080] As the negative electrode active material, a material having the property of intercalating and releasing lithium ions, sodium ions, or magnesium ions may be used.
[0081] When the negative electrode active material is a material that has the property of intercalating and releasing lithium ions, the negative electrode active material can be, for example, a metallic material, a carbon material, or an oxide, nitride, tin compound, silicon compound, etc. The metallic material may be an elemental metal. The metallic material may be an alloy. Examples of metallic materials include lithium metal and lithium alloys. Examples of carbon materials include natural graphite, artificial graphite, graphite-carbon fiber, and resin-fired carbon. Examples of oxides include oxides of lithium and transition metal elements.
[0082] The shape of the negative electrode active material is not particularly limited. The shape of the negative electrode active material may be, for example, needle-shaped, spherical, or ellipsoidal. For example, the shape of the negative electrode active material may be particulate.
[0083] The thickness of the negative electrode active material layer 103 may be 5 μm or more and 150 μm or less. When the thickness of the negative electrode active material layer 103 is 5 μm or more, a sufficient energy density of the battery 10 can be ensured. When the thickness of the negative electrode active material layer 103 is 150 μm or less, the battery 10 can operate at high power.
[0084] Battery 10 is typically a solid-state battery that does not contain an electrolyte.
[0085] At least one of the components selected from the group consisting of a positive electrode active material layer 101, a solid electrolyte layer 102, and a negative electrode active material layer 103 may contain a binder for the purpose of improving the adhesion between particles. Examples of binders include polyvinylidene fluoride, polytetrafluoroethylene, polyethylene, polypropylene, aramid resin, polyamide, polyimide, polyamideimide, polyacrylonitrile, polyacrylic acid, polyacrylate methyl ester, polyacrylate ethyl ester, polyacrylate hexyl ester, polymethacrylic acid, polymethacrylate methyl ester, polymethacrylate ethyl ester, polymethacrylate hexyl ester, polyvinyl acetate, polyvinylpyrrolidone, polyether, polyethersulfone, hexafluoropolypropylene, styrene-butadiene rubber, and carboxymethylcellulose. Furthermore, copolymers of two or more materials selected from the group consisting of tetrafluoroethylene, hexafluoroethylene, hexafluoropropylene, perfluoroalkyl vinyl ether, vinylidene fluoride, chlorotrifluoroethylene, ethylene, propylene, pentafluoropropylene, fluoromethyl vinyl ether, acrylic acid, and hexadiene can also be used as binders. Alternatively, a mixture of two or more materials selected from the above materials may be used as a binder.
[0086] At least one of the components selected from the group consisting of a positive electrode active material layer 101, a solid electrolyte layer 102, and a negative electrode active material layer 103 may contain a conductive additive for the purpose of improving electronic conductivity. Examples of conductive additives include conductive materials such as acetylene black, carbon black, graphite, or carbon fiber.
[0087] Examples of the battery shape of the battery 10 in Embodiment 1 include coin-shaped, cylindrical, rectangular, sheet-shaped, button-shaped, flat, and stacked types.
[0088] <Battery manufacturing method> The battery 10 according to this embodiment can be manufactured, for example, by the following method. The following method is an example in which the solid electrolyte layer 102 contains a sulfide solid electrolyte 202 as an odorant.
[0089] A positive electrode material containing a positive electrode active material, a negative electrode material containing a negative electrode active material, and a solid electrolyte material containing a halide solid electrolyte 201 and a sulfide solid electrolyte 202 are prepared. In the solid electrolyte material, the halide solid electrolyte 201 and the sulfide solid electrolyte 202 may be pre-mixed.
[0090] The positive electrode material, solid electrolyte material, and negative electrode material are stacked in this order and then pressure-molded. This yields a battery 10 having a positive electrode active material layer 101, a solid electrolyte layer 102, and a negative electrode active material layer 103 in this order. The battery 10 can also be obtained by stacking the negative electrode material, solid electrolyte material, and positive electrode material in this order and then pressure-molding.
[0091] (Embodiment 2) Embodiment 2 will be described below. Descriptions that overlap with Embodiment 1 will be omitted as appropriate.
[0092] Figure 2 is a cross-sectional view showing the schematic configuration of the solid-state battery 20 in Embodiment 2. In this disclosure, "solid-state battery" means a battery using a solid electrolyte. A solid-state battery is typically an all-solid-state battery that does not contain an electrolyte.
[0093] The solid battery 20 in Embodiment 2 comprises an outer casing 40 having an internal space 41, a power generation element 30 disposed in the internal space 41, and an odor substance 401 disposed outside the power generation element 30 in the internal space 41.
[0094] With the above configuration, the odor substance 401 allows for early detection of leaks, such as electrolytes from the power generation element 30. If a leak is detected, charging or discharging of the solid battery 20 can be promptly stopped, and the malfunction can be notified to the outside. This improves the safety of the solid battery 20.
[0095] The power generation element 30 comprises a positive electrode active material layer 301, a negative electrode active material layer 303, and a solid electrolyte layer 302 located between the positive electrode active material layer 301 and the negative electrode active material layer 303.
[0096] The solid-state battery 20 further comprises a first current collector 501 positioned above the power generation element 30, and a second current collector 502 positioned below the power generation element 30. The first current collector 501 is a positive electrode current collector and is positioned above the positive electrode active material layer 301. The second current collector 502 is a negative electrode current collector and is positioned below the negative electrode active material layer 303.
[0097] In this embodiment, the odor substance 401 is placed on top of the first current collector 501. The odor substance 401 may also be placed on top of the first current collector 501. With this configuration, the odor substance 401 is less likely to adversely affect the characteristics of the solid-state battery 20.
[0098] The odorous substance 401 may be a solid. With the above configuration, the odorous substance 401 is less likely to seep into the power generation element 30, so the odorous substance 401 is less likely to adversely affect the characteristics of the solid battery 20.
[0099] The odorant substance 401 has the form of a thin film on the upper part of the first current collector 501. The odorant substance 401 in the form of a thin film covers, for example, the entire upper surface of the first current collector 501. With such a structure, it is easy to minimize the amount of odorant substance 401 and avoid increasing the thickness of the solid battery 20. However, the odorant substance 401 may cover only a part of the upper surface of the first current collector 501.
[0100] In this embodiment, the first current collector 501 and the second current collector 502 are a positive electrode current collector and a negative electrode current collector, respectively. That is, the odor substance 401 is provided on the positive electrode current collector. However, the odor substance 401 may also be provided on the upper part of the negative electrode current collector. The odor substance 401 may be provided only on the upper part of the first current collector 501, or only on the upper part of the second current collector 502, or on the upper part of both the first current collector 501 and the second current collector 502.
[0101] Alternatively, the odorous substance 401 may be provided in contact with the side surface of the power generation element 30 (the surface not in contact with the current collector). In this case, an increase in the thickness of the solid battery 20 due to the odorous substance 401 can be avoided.
[0102] The odorant substance 401 may contain a sulfide solid electrolyte. The sulfide solid electrolyte has the function of improving the output characteristics of the solid battery. Therefore, with the above configuration, the deterioration of the performance of the solid battery 20 due to the addition of the odorant substance 401 is suppressed. Thus, it is possible to improve the safety of the solid battery 20 while maintaining its performance.
[0103] As the sulfide solid electrolyte, the sulfide solid electrolyte 202 described in Embodiment 1 can be used.
[0104] Odor substance 401 may contain only sulfide solid electrolyte. "Containing only sulfide solid electrolyte" means that, excluding unavoidable impurities, no materials other than sulfide solid electrolyte have been intentionally added to odor substance 401. For example, raw materials for sulfide solid electrolyte and by-products generated during the production of sulfide solid electrolyte are included in unavoidable impurities.
[0105] If the odorous substance 401 contains a sulfide solid electrolyte, the ratio of the mass of the sulfide solid electrolyte to the mass of the power generation element 30 may be 25% or less, 5% or less, 1% or less, 0.1% or less, or 0.01% or less.
[0106] The odorant substance 401 may be a material other than a sulfide solid electrolyte. As the odorant substance 401 other than a sulfide solid electrolyte, the material described in Embodiment 1 may be used.
[0107] The odor substance 401 may contain only materials other than sulfide solid electrolytes. "Containing only materials other than sulfide solid electrolytes" means that, excluding unavoidable impurities, no materials other than sulfide solid electrolytes have been intentionally added to the odor substance 401.
[0108] If the odorous substance 401 contains materials other than the sulfide solid electrolyte, the ratio of the mass of materials other than the sulfide solid electrolyte to the mass of the power generation element 30 is 1% or less.
[0109] The first current collector 501 and the second current collector 502 are made of a conductive material such as metal. Examples of metals include copper, aluminum, nickel, iron, platinum, gold, and alloys thereof. The first current collector 501 and the second current collector 502 may have shapes such as foil, plate-like bodies, or mesh-like bodies. The thickness of the first current collector 501 and the second current collector 502 is, for example, 5 μm or more and 100 μm or less.
[0110] The power generation element 30 may also contain a halogen solid electrolyte. With the above configuration, the safety of the solid battery 20 can be further improved.
[0111] At least one layer selected from the group consisting of a positive electrode active material layer 301, a negative electrode active material layer 303, and a solid electrolyte layer 302 may contain a halide solid electrolyte. As the halide solid electrolyte, the halide solid electrolyte 201 described in Embodiment 1 may be used.
[0112] The solid electrolyte layer 302 is a layer containing a solid electrolyte. The solid electrolyte described in the solid electrolyte layer 102 of Embodiment 1 can be used as the solid electrolyte contained in the solid electrolyte layer 302.
[0113] The positive electrode active material layer 301 is a layer containing a positive electrode active material. As the positive electrode active material, the positive electrode active material described in the positive electrode active material layer 101 of Embodiment 1 may be used. The positive electrode active material layer 301 may also contain a solid electrolyte. As the solid electrolyte, the solid electrolyte described in the solid electrolyte layer 102 of Embodiment 1 may be used.
[0114] The negative electrode active material layer 303 is a layer containing a negative electrode active material. As the negative electrode active material, the negative electrode active material described in the negative electrode active material layer 103 of Embodiment 1 may be used. The negative electrode active material layer 303 may also contain a solid electrolyte. As the solid electrolyte, the solid electrolyte described in the solid electrolyte layer 102 of Embodiment 1 may be used.
[0115] The thicknesses of the positive electrode active material layer 301, the negative electrode active material layer 303, and the solid electrolyte layer 302 are as described in the positive electrode active material layer 101, the negative electrode active material layer 103, and the solid electrolyte layer 102 of Embodiment 1.
[0116] At least one selected from the group consisting of the positive electrode active material layer 301, the solid electrolyte layer 302, and the negative electrode active material layer 303 may contain a binder for the purpose of improving the adhesion between particles. The binder described in Embodiment 1 may be used as the binder.
[0117] At least one selected from the group consisting of a positive electrode active material layer 301, a solid electrolyte layer 302, and a negative electrode active material layer 303 may contain a conductive additive for the purpose of improving electronic conductivity. The conductive additive described in Embodiment 1 may be used as the conductive additive.
[0118] The outer casing 40 is a hollow container in which the power generation element 30 can be placed in the internal space 41. In this embodiment, the outer casing 40 is substantially rectangular in shape. The outer casing 40 may be made of a metal material or a resin material. Typically, the outer casing 40 may be made of a laminate obtained by laminating two layers of resin film with a metal foil placed between the resin films. The laminate may typically be an aluminum laminate film.
[0119] Examples of the solid-state battery 20 in Embodiment 2 include coin-shaped, cylindrical, prismatic, sheet-shaped, button-shaped, flat, and stacked types.
[0120] <Method of manufacturing solid-state batteries> The solid-state battery 20 according to this embodiment can be manufactured, for example, by the following method.
[0121] A positive electrode material containing a positive electrode active material, a negative electrode material containing a negative electrode active material, a solid electrolyte material, a first current collector 501 as a positive electrode current collector, and a second current collector 502 as a negative electrode current collector are prepared.
[0122] A positive electrode material, a solid electrolyte material, a negative electrode material, and a second current collector 502 are laminated on a first current collector 501 in this order and then pressure-molded. This yields a laminate containing a power generation element 30 having a positive electrode active material layer 301, a solid electrolyte layer 302, and a negative electrode active material layer 303 in this order. Such a laminate can also be obtained by laminating a negative electrode material, a solid electrolyte material, a positive electrode material, and a first current collector 501 on a second current collector 502 in this order and then pressure-molding.
[0123] The resulting laminate is placed in the internal space 41 of the outer casing 40 such that the second current collector 502 is below the first current collector 501. The odor substance 401 is placed on top of the laminate, i.e., above the first current collector 501. This gives rise to the solid-state battery 20. [Industrial applicability]
[0124] The batteries and solid-state batteries described herein can be used, for example, as all-solid-state lithium secondary batteries. [Explanation of Symbols]
[0125] 10 batteries 20 solid state battery 30 Power generation elements 40 Exterior 41 Interior space 101,301 Cathode active material layer 102,302 Solid electrolyte layer 103,303 Negative electrode active material layer 201 Halide Solid Electrolytes 202 Sulfide solid electrolyte 401 Odor substances 501 First current collector 502 Second current collector
Claims
1. The device comprises a positive electrode active material layer, a negative electrode active material layer, and a solid electrolyte layer located between the positive electrode active material layer and the negative electrode active material layer. A battery that meets either requirement (i) or (ii) below. (i) At least one layer selected from the group consisting of the positive electrode active material layer, the negative electrode active material layer, and the solid electrolyte layer comprises a halide solid electrolyte and a sulfide solid electrolyte, The ratio of the mass of the sulfide solid electrolyte to the total mass of the positive electrode active material layer, the negative electrode active material layer, and the solid electrolyte layer is 1% or less. (ii) At least one layer selected from the group consisting of the positive electrode active material layer, the negative electrode active material layer, and the solid electrolyte layer comprises a halogenated solid electrolyte and an odorant, The ratio of the mass of the odorous substance to the total mass of the positive electrode active material layer, the negative electrode active material layer, and the solid electrolyte layer is 1% or less.
2. In the above requirement (i), The ratio of the mass of the sulfide solid electrolyte to the total mass of the positive electrode active material layer, the negative electrode active material layer, and the solid electrolyte layer is 0.1% or less. The battery according to claim 1.
3. In the above requirement (i), The ratio of the mass of the sulfide solid electrolyte to the total mass of the positive electrode active material layer, the negative electrode active material layer, and the solid electrolyte layer is 0.01% or less. The battery according to claim 1.
4. In the above requirement (i), The sulfide solid electrolyte is Li 2 S-P 2 S 5 、Li 2 S-SiS 2 、Li 2 S-B 2 S 3 、Li 2 S-GeS 2 、Li 3.25 Ge 0.25 P 0.75 S 4 、and Li 10 GeP 2 S 12 and includes at least one selected from the group consisting of The battery according to claim 1.
5. In the above requirement (ii), The odorous substance is a substance that does not have lithium ion conductivity. The battery according to claim 1.
6. The aforementioned halide solid electrolyte comprises Li, at least one selected from the group consisting of metal elements other than Li and metalloid elements, and at least one selected from the group consisting of F, Cl, Br, and I. The battery according to any one of claims 1 to 5.
7. The aforementioned halogen solid electrolyte is represented by the following compositional formula (1): L α M β X γ ・・・Form (1) α, β, and γ are each values greater than 0. M is at least one selected from the group consisting of metallic elements and metalloid elements other than Li. X is at least one selected from the group consisting of F, Cl, Br, and I. The battery according to claim 6.
8. In the above composition formula (1), M contains yttrium. The battery according to claim 7.
9. An exterior body having an internal space, The power generation element arranged in the aforementioned internal space, In the aforementioned internal space, an odorous substance is placed outside the power generation element, Equipped with, The power generation element comprises a positive electrode active material layer, a negative electrode active material layer, and a solid electrolyte layer located between the positive electrode active material layer and the negative electrode active material layer. A solid-state battery in which at least one layer selected from the group consisting of the positive electrode active material layer, the negative electrode active material layer, and the solid electrolyte layer contains a halide solid electrolyte.
10. The odorous substance is a solid. The solid-state battery according to claim 9.
11. The odorous substance includes a sulfide solid electrolyte. The solid-state battery according to claim 9.
12. The system further comprises a first current collector positioned above the power generation element and a second current collector positioned below the power generation element. The odorous substance is located on the upper part of the first current collector. A solid-state battery according to any one of claims 9 to 11.