Battery and method for manufacturing the battery

Abstract

The battery according to the present disclosure comprises: a first electrode; a second electrode; a solid electrolyte layer disposed between the first electrode and the second electrode; a temperature sensor; and a first lead terminal. The temperature sensor includes at least one component selected from the group consisting of thermistors and resistance thermometers and is in contact with the first electrode, and the first lead terminal is in contact with the temperature sensor.

Description

[Technical Field]

[0001] The present disclosure relates to batteries and methods for manufacturing batteries. [Background technology]

[0002] Patent Document 1 discloses an electricity storage device equipped with a temperature detection unit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-272113 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present disclosure is to provide a battery with improved reliability. [Means for solving the problem]

[0005] The battery of the present disclosure comprises: A first electrode; A second electrode; a solid electrolyte layer disposed between the first electrode and the second electrode; A temperature sensor; A first lead-out terminal; Equipped with the temperature sensor includes at least one selected from the group consisting of a thermistor and a resistance temperature detector, and is in contact with the first electrode; The first lead-out terminal is in contact with the temperature sensor. [Effects of the Invention]

[0006] The present disclosure provides batteries with improved reliability. [Brief explanation of the drawings]

[0007] [Figure 1]FIG. 1 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to a second embodiment. [Figure 3] FIG. 3 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to a third embodiment. [Figure 4] FIG. 4 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to a fourth embodiment. [Figure 5] FIG. 5 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to a fifth embodiment. [Figure 6] FIG. 6 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to a sixth embodiment. [Figure 7] FIG. 7 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to a seventh embodiment. [Figure 8] FIG. 8 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to an eighth embodiment. [Figure 9] FIG. 9 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to a ninth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0009] The embodiments described below are all comprehensive or specific examples, and the numerical values, shapes, materials, arrangement and connection of components, manufacturing processes, and the order of manufacturing processes shown in the following embodiments are merely examples and are not intended to limit the present disclosure.

[0010] In this specification, terms indicating the relationship between elements, such as parallelism, terms indicating the shape of elements, such as rectangle, and numerical ranges are not expressions that only express a strict meaning, but are expressions that also include a substantially equivalent range, for example, a difference of about a few percent.

[0011] The drawings are schematic diagrams and are not necessarily drawn to scale. Therefore, for example, the scales of the drawings do not necessarily match. In addition, the same reference numerals are used in the drawings to designate substantially the same components, and redundant explanations are omitted or simplified.

[0012] In this specification and the drawings, the x-axis, y-axis, and z-axis represent the three axes of a three-dimensional Cartesian coordinate system. In each embodiment, the z-axis direction is the thickness direction of the battery. In this specification, the "thickness direction" refers to the direction perpendicular to the plane on which each layer of the battery is stacked.

[0013] In this specification, "plan view" means a view of the battery along the stacking direction of the battery, and "thickness" in this specification means the length of the battery and each layer in the stacking direction.

[0014] In this specification, the terms "inside" and "outside" refer to the center side of the battery as "inside" and the peripheral side of the battery as "outside" when the battery is viewed along the stacking direction of the battery.

[0015] In this specification, the terms "upper" and "lower" in the battery configuration do not refer to the upper direction (vertically upper) and lower direction (vertically lower) in absolute spatial recognition, but are used as terms defined by a relative positional relationship based on the stacking order in the stacking configuration. Furthermore, the terms "upper" and "lower" are used not only when two components are arranged with a gap between them and another component is present between them, but also when two components are arranged closely together and the two components are in contact with each other.

[0016] (First embodiment) The battery according to the first embodiment will be described below.

[0017] A battery according to a first embodiment includes a first electrode, a second electrode, a solid electrolyte layer disposed between the first and second electrodes, a temperature sensor, and a first lead terminal. The temperature sensor includes at least one selected from the group consisting of a thermistor and a resistance temperature detector, and is in contact with the first electrode. The first lead terminal is in contact with the temperature sensor.

[0018] According to the above configuration, the temperature of the battery operating unit can be directly monitored, thereby obtaining highly accurate and responsive detection results. Therefore, if the battery generates abnormal heat, the battery can be reliably and quickly disconnected from the external circuit. As a result, deterioration of the battery's characteristics and reliability (e.g., battery life) can be suppressed. Battery fire or smoke generation can also be suppressed. Furthermore, by dissipating heat from within the battery through the draw-out terminal, deterioration of the battery's characteristics and abnormal heat generation can be suppressed. Therefore, the battery according to the first embodiment can achieve high reliability even in thin, large-area batteries that require high safety. In other words, a large, thin battery with high safety can be realized.

[0019] As described in the [Background Art] section, Patent Document 1 discloses an electricity storage device equipped with a temperature detection unit. However, the temperature detection unit, which corresponds to the temperature sensor of the battery according to the first embodiment, has a structure coated with, for example, an insulating resin with high thermal resistance, and is in contact with the power generating element via the resin. This poses problems with temperature detection responsiveness and temperature accuracy. Furthermore, because the temperature detection unit is coated with resin, the resin deteriorates over time and becomes prone to denaturation and breakage. Therefore, the electricity storage device disclosed in Patent Document 1 also has reliability issues.

[0020] FIG. 1 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to a first embodiment.

[0021] Fig. 1(a) is a cross-sectional view of a battery 1000 according to a first embodiment. Fig. 1(b) is a plan view of the battery 1000 according to the first embodiment as seen from above in the z-axis direction. Fig. 1(a) shows a cross section taken along line II in Fig. 1(b).

[0022] As shown in FIG. 1, the battery 1000 includes a first electrode 100, a second electrode 200, a solid electrolyte layer 300, a thermistor 400 provided as a temperature sensor, and a first lead terminal 410.

[0023] Here, a thermistor will be described as an example of a temperature sensor, but the temperature sensor is not limited to this. The temperature sensor may include a resistance temperature detector. The resistance temperature detector may include, for example, platinum.

[0024] The solid electrolyte layer 300 is disposed between the first electrode 100 and the second electrode 200. The solid electrolyte layer 300 may be in contact with both the first electrode 100 and the second electrode 200.

[0025] The thermistor 400 is in contact with the first electrode 100. To detect the temperature of the battery operating section with higher accuracy and higher responsiveness, the thermistor 400 is preferably in direct contact with the first electrode 100. That is, the thermistor 400 is disposed in contact with the first electrode 100 without any other member, such as a protective film, interposed therebetween.

[0026] The lead-out terminal 410 is in contact with the thermistor 400 .

[0027] The battery 1000 is, for example, an all-solid-state battery.

[0028] The first electrode 100 includes, for example, a first current collector 110 and a first active material layer 120.

[0029] The second electrode 200 includes, for example, a second current collector 210 and a second active material layer 220.

[0030] In the battery 1000 according to the first embodiment, for example, the thermistor 400 may be in contact with the first current collector 110. For example, a main surface of the thermistor 400 may be in contact with the first current collector 110. The thermistor 400 may be in direct contact with the first current collector 110. The first current collector 110 may also serve as a terminal of the thermistor 400, which is a temperature sensor. The temperature sensor terminal refers to a terminal for extracting a signal from the temperature sensor. In this case, the first lead-out terminal 410 may be in contact with the other main surface of the thermistor 400. These configurations enable the temperature of the battery operating unit to be detected with higher accuracy and responsiveness, and minimize the increase in thickness of the battery 1000 due to the provision of a temperature sensor. Therefore, a large, thin battery with high safety can be realized.

[0031] In the battery 1000 according to the first embodiment, the thermistor 400 may be electrically connected to the first current collector 110. Even with this configuration, the first current collector 110 can be used as a terminal of the thermistor 400, which is a temperature sensor.

[0032] The thermistor 400 has an active part whose electrical resistance changes with temperature changes. By measuring the change in electrical resistance of the active part, the temperature change of the battery 1000 can be detected.

[0033] The active portion of the thermistor 400 may be contained within the first electrode 100 and may be in contact with the first electrode 100. In other words, the active portion of the thermistor 400 does not have to be exposed from the first electrode 100. With the above configuration, temperature changes in the vicinity of the first active material layer 120, which is prone to heat generation, can be measured more accurately and with good responsiveness. As a result, fire or smoke generation from the battery 1000 can be more easily prevented.

[0034] The thermistor 400 may be contained within the first electrode 100. In other words, the entire thermistor 400 does not have to be exposed from the first electrode 100. With the above configuration, the influence of heat radiation from the surface of the thermistor 400 can be reduced, enabling more accurate and responsive temperature measurement. In addition, heat generated inside the first electrode 100 can be measured. This allows accurate and rapid monitoring of heat generation in the battery 1000, making it easier to prevent fire or smoke from the battery 1000. Furthermore, heat generated in the first electrode 100 can be released to the outside of the battery from the first lead terminal 410, thereby preventing characteristic degradation and abnormal heat generation.

[0035] The thermistor 400 may be disposed in the center of the first electrode 100. In this case, the outer peripheral side surface of the thermistor 400 is in contact with, for example, the first active material layer 120 and is not exposed. With the above configuration, it is possible to measure the parts of the battery 1000 that are likely to generate heat, which makes it easier to prevent the battery 1000 from catching fire or emitting smoke. Furthermore, heat generated in the center, which is difficult to dissipate, can be released via the first lead terminal 410.

[0036] The first current collector 110, the first active material layer 120, the solid electrolyte layer 300, the second active material layer 220, the second current collector 210, and the thermistor 400 may all have a roughly rectangular shape in a plan view. The shape does not have to be rectangular.

[0037] In FIG. 1, the first current collector 110, the first active material layer 120, the solid electrolyte layer 300, the second active material layer 220, and the second current collector 210 are all the same size and have the same outline in a plan view, but this is not limited to this.

[0038] The first active material layer 120 may be smaller than the second active material layer 220 .

[0039] The first active material layer 120 and the second active material layer 220 may be smaller than the solid electrolyte layer 300 .

[0040] For example, when the solid electrolyte layer 300 covers at least one of the first active material layer 120 and the second active material layer 220, a portion of the solid electrolyte layer 300 may be in contact with at least one of the first current collector 110 and the second current collector 210.

[0041] A portion of the thermistor 400 may be exposed to the outside of the first electrode 100 .

[0042] The thermistor 400 may be in contact not only with the first electrode 100 but also with the solid electrolyte layer 300. The thermistor 400 may also be arranged so as to be in contact with the second electrode 200 in addition to the solid electrolyte layer 300.

[0043] The battery 1000 may include multiple thermistors. For example, the battery 1000 may include two thermistors, one of which is in contact with the first electrode 100 and the other of which is in contact with the second electrode 200.

[0044] The first electrode 100 may be a positive electrode. In this case, the second electrode 200 is a negative electrode. The first current collector 110 and the first active material layer 120 are a positive electrode current collector and a positive electrode active material layer, respectively. The second current collector 210 and the second active material layer 220 are a negative electrode current collector and a negative electrode active material layer, respectively. With the above configuration, the temperature of a portion of the battery 1000 that is likely to generate heat (i.e., the positive electrode) can be measured accurately and with good responsiveness, making it easier to prevent the battery 1000 from catching fire or emitting smoke.

[0045] The first electrode 100 may be a negative electrode and the second electrode 200 may be a positive electrode.

[0046] Hereinafter, the first current collector 110 and the second current collector 210 may be collectively referred to simply as "current collectors." The first active material layer 120 and the second active material layer 220 may be collectively referred to simply as "active material layers."

[0047] The current collector may be made of any material that is electrically conductive.

[0048] The current collector may be, for example, a foil, plate, or mesh made of stainless steel, nickel (Ni), aluminum (Al), iron (Fe), titanium (Ti), copper (Cu), palladium (Pd), gold (Au), platinum (Pt), or an alloy of two or more of these metals.

[0049] The material of the current collector can be selected taking into consideration the manufacturing process, operating temperature, operating pressure, battery operating potential applied to the current collector, or electrical conductivity. The material of the current collector can also be selected taking into consideration the tensile strength or heat resistance required for the battery. The current collector can be, for example, a high-strength electrolytic copper foil or a clad material in which foils of different metals are laminated.

[0050] The current collector may have a thickness of, for example, 10 μm or more and 100 μm or less.

[0051] The surface of the current collector may be processed to have a roughened surface with irregularities to enhance adhesion with the active material layer (i.e., the first active material layer 120 or the second active material layer 220). This, for example, strengthens the bonding at the current collector interface, improving the mechanical and thermal reliability and cycle characteristics of the battery 1000. Furthermore, the increased contact area between the current collector and the active material layer reduces electrical resistance.

[0052] The first active material layer 120 may be in contact with the first current collector 110. The first active material layer 120 may cover the entire main surface of the first current collector 110.

[0053] The positive electrode active material layer contains a positive electrode active material.

[0054] The positive electrode active material is a material in which metal ions such as lithium (Li) ions or magnesium (Mg) ions are inserted or extracted into or from the crystalline structure at a higher potential than the negative electrode, and as a result, oxidation or reduction occurs.

[0055] The positive electrode active material is, for example, a compound containing lithium and a transition metal element. The compound is, for example, an oxide containing lithium and a transition metal element, or a phosphate compound containing lithium and a transition metal element.

[0056] Examples of oxides containing lithium and a transition metal element are lithium nickel composite oxides such as LiNi x M 1-x O2 (where M is at least one selected from the group consisting of Co, Al, Mn, V, Cr, Mg, Ca, Ti, Zr, Nb, Mo, and W, and 0 < x ≦ 1 is satisfied), such as layered oxides such as lithium cobaltate (LiCoO2), lithium nickelate (LiNiO2), and lithium manganate (LiMn2O4), or lithium manganate having a spinel structure (for example, LiMn2O4, Li2MnO3, or LiMO2).

[0057] An example of a phosphate compound containing lithium and a transition metal element is lithium iron phosphate (LiFePO4) having an olivine structure.

[0058] As the positive electrode active material, sulfides such as sulfur (S) and lithium sulfide (Li2S) may be used. In this case, lithium niobate (LiNbO3) or the like may be coated on or added to the positive electrode active material particles.

[0059] Only one of these materials may be used as the positive electrode active material, or two or more of these materials may be combined and used.

[0060] In order to enhance lithium ion conductivity or electron conductivity, the positive electrode active material layer may contain a material other than the positive electrode active material in addition to the positive electrode active material. That is, the positive electrode active material layer may be a binder layer. Examples of the material are solid electrolytes such as inorganic solid electrolytes and sulfide solid electrolytes, conductive aids such as acetylene black, or binders for binding such as polyethylene oxide and polyvinylidene fluoride.

[0061] The first active material layer 120 may have a thickness of not less than 5 μm and not more than 300 μm.

[0062] The thermistor 400 may have a thickness of greater than or equal to 10 μm and up to 1000 μm.

[0063] At least a portion of the first lead-out terminal 410 extends to the side surface of the battery 1000, with the end exposed. Therefore, the temperature can be monitored by measuring the resistance between the first current collector 110, which can function as a terminal of the thermistor 400, and the first lead-out terminal 410 (i.e., across the thermistor 400).

[0064] At least a portion of the surface of the first lead terminal 410 may be roughened. The height difference between the protrusions and recesses of the roughened surface, i.e., the maximum height roughness Rz (JIS B 0601:2013), may be, for example, 0.5 μm to 5 μm. This may be approximately the same as the size of the thermistor particles. This strengthens the bond between the thermistor 400 and the first electrode 100 or the first active material layer 120 through an anchoring effect. This therefore increases the reliability of the bond between the thermistor 400 and the first electrode 100. As a result, the long-term stability of temperature accuracy and responsiveness is improved.

[0065] The material of the lead-out terminal 410 may be a conductive metal.

[0066] Examples of conductive metals are Cu, Ag, Pd, Pt, or Au, which have high electrical conductivity.

[0067] The thickness of the first lead terminal 410 may be not less than 0.5 μm and not more than 100 μm.

[0068] The first lead-out terminal 410 may be thinner than the thermistor 400. This reduces thermal shock caused by the difference in thermal expansion coefficient between the conductor layer constituting the first lead-out terminal 410 and the thermistor material during thermal cycling. As a result, for example, it is possible to prevent the thermistor 400 from peeling off from the conductor layer constituting the first lead-out terminal 410 or to prevent cracks from occurring in the thermistor 400. This improves measurement accuracy and reliability.

[0069] The thermistor 400 is made of, for example, a material whose electrical resistance has a negative temperature coefficient (NTC characteristic), that is, the thermistor 400 may be an NTC thermistor.

[0070] The thermistor 400 may contain a ceramic material. This allows the battery 1000 according to the first embodiment to incorporate a highly reliable thermistor that can be used over a wide temperature range. Furthermore, for example, in the stacking process of the battery 1000, the thermistor 400 can be incorporated into the battery 1000 in the form of a thick-film thermistor by powder formation (i.e., a coating process). Alternatively, it can be embedded in the form of a plate-shaped ceramic sintered element. This allows the thermistor 400 to be incorporated into the battery 1000 during the battery fabrication process, thereby achieving a thermistor-embedded battery with excellent productivity.

[0071] The ceramic material may be an oxide ceramic. That is, the thermistor 400 may contain an oxide ceramic. This improves high-temperature resistance and chemical stability, resulting in high characteristic stability against heat generation and oxidation-reduction reactions within the power-generating element during battery operation. As a result, temperature measurement within the battery can be performed with high reliability.

[0072] The oxide ceramic may be, for example, a transition metal oxide containing at least one selected from the group consisting of Ni, Mn, Co, and Fe.

[0073] Thermistor 400 may be an NTC thermistor composition using an oxide semiconductor ceramic material. For example, composite oxides including Mn-Ni-Co, Mn-Ni-Co-Fe, Mn-Ni-Co-Cr, Co-Cu-Ni, Co-Cu-Li, Co-Cu-Ni-Li, Co-Cu-Ni-Si, Mn-Ni-Cr, Mg-Al-Cr, or La-Co may be used for thermistor 400. In this way, thermistor 400 may be made of a ceramic material containing a transition metal oxide.

[0074] The transition metal oxide may contain a crystalline phase with a spinel structure as its main component. This improves high-temperature resistance and chemical stability, resulting in high stability of characteristics against heat generation and oxidation-reduction during battery operation. Furthermore, the resistance value and thermistor constant of the thermistor 400 can be controlled over a wide range, enabling measurements to be made over a temperature range suited to the application. The thermistor constant here refers to the coefficient of the temperature gradient of resistance, hereinafter referred to as the "B constant."

[0075] The material of the thermistor 400 may have a room temperature resistivity of 1000 Ω·cm to 3000 Ω·cm (25° C.) and a B constant of 3000 K to 6000 K (e.g., between 25° C. and 50° C.). The resistance of a material with a large B constant has a large temperature dependence and can be used to improve temperature detection accuracy.

[0076] Multiple thermistors with different characteristics may be used in combination, allowing the resistance value or B constant to be adjusted depending on the application.

[0077] Typical active materials contained in the active material layer are often oxides containing transition metals (e.g., Co, Mn, or Ni). Therefore, thermistors containing transition metal oxides have thermal expansion characteristics similar to those of electrode materials, which can suppress structural defects (e.g., cracks) that occur during thermal cycling. Therefore, even when the thermistor 400 is encapsulated in the first electrode 100, temperature sensing can be performed with high reliability.

[0078] When the thermistor 400 is an oxide ceramic, it is generally synthesized by sintering at approximately 1000° C. to 1400° C. Therefore, it is stable even at temperatures (e.g., 500° C. or higher) that would cause the battery to burn out, and has high heat resistance.

[0079] The high-temperature stability of a thermistor can be determined by heat-treating a thermistor element (e.g., a sintered body or powder) within the operating temperature range and observing changes in its properties or state, the presence or absence of cracks, or by thermal analysis (TG-DTA). Generally, there is little change at temperatures lower than the sintering temperature. Note that property changes include, for example, changes in resistance and B constant. Note that state changes include, for example, crystalline phase changes. Crystalline phase changes are confirmed by X-ray diffraction (XRD). The presence or absence of cracks is confirmed using an optical microscope or scanning electron microscope (SEM). The approximate sintering temperature can be determined by knowing the thermistor's composition. The thermistor's composition can be measured by X-ray fluorescence analysis (XRF) or energy dispersive X-ray spectroscopy (EDS). Because thermistor materials are subject to minimal influence from trace additives, compositional analysis such as EDS is sufficient to roughly estimate the thermistor's sintering temperature.

[0080] The material of the thermistor 400 may be a sintered bulk, a compacted powder structure consisting of crushed particles of a sintered composition, or a thick-film coated structure. For thick-film coated thermistors, binders such as polyethylene oxide, polyvinylidene fluoride, or butyral resin may be used. Plasticizers such as benzyl butyl phthalate (BBP) or dibutyl phthalate (DBP) may also be included. This strengthens the bond with the surroundings by conforming to the irregularities of the compacted powder structure or conductor electrode layer when pressurized, thereby reducing structural defects.

[0081] The second active material layer 220 may be in contact with the second current collector 210. The second active material layer 220 may cover the entire main surface of the second current collector 210.

[0082] The negative electrode active material layer contains a negative electrode active material.

[0083] The negative electrode active material is a material in which metal ions such as lithium (Li) ions or magnesium (Mg) ions are inserted or extracted into or from the crystalline structure at a lower potential than the positive electrode, and is therefore oxidized or reduced.

[0084] Examples of the negative electrode active material include carbon materials such as natural graphite, artificial graphite, graphite carbon fiber, and resin-baked carbon, or alloy-based materials mixed with a solid electrolyte. Examples of alloy-based materials include LiAl, LiZn, Li3Bi, Li3Cd, Li3Sb, Li4Si, and Li 4.4 Pb, Li 4.4 Sn, Li 0.17 C, and lithium alloys such as LiC6, lithium titanate (Li4Ti5O 12 ), zinc oxide (ZnO), or silicon oxide (SiO x ) are metal oxides such as

[0085] The negative electrode active material may be made of only one of these materials, or may be made of a combination of two or more of these materials.

[0086] To enhance lithium ion conductivity or electron conductivity, the negative electrode active material layer may contain, in addition to the negative electrode active material, a material other than the negative electrode active material. Examples of such materials include a solid electrolyte such as an inorganic solid electrolyte or a sulfide-based solid electrolyte, a conductive additive such as acetylene black, or a binding binder such as polyethylene oxide and polyvinylidene fluoride.

[0087] The second active material layer 220 may have a thickness of not less than 5 μm and not more than 300 μm.

[0088] The solid electrolyte layer 300 includes a solid electrolyte. For example, the solid electrolyte layer 300 contains a solid electrolyte as a main component. The solid electrolyte layer 300 may be made of only a solid electrolyte.

[0089] The solid electrolyte may be a known ion-conductive solid electrolyte for batteries, such as a solid electrolyte that conducts metal ions such as lithium ions or magnesium ions.

[0090] As the solid electrolyte, for example, an inorganic solid electrolyte such as a sulfide-based solid electrolyte or an oxide-based solid electrolyte can be used.

[0091] Examples of sulfide-based solid electrolytes include Li2S-P2S5-based, Li2S-SiS2-based, Li2S-B2S3-based, Li2S-GeS2-based, Li2S-SiS2-LiI-based, Li2S-SiS2-Li3PO4-based, Li2S-Ge2S2-based, Li2S-GeS2-P2S5-based, and Li2S-GeS2-ZnS-based.

[0092] The oxide-based solid electrolyte is, for example, a lithium-containing metal oxide, a lithium-containing metal nitride, lithium phosphate (Li3PO4), or a lithium-containing transition metal oxide. Examples of lithium-containing metal oxides are Li2O-SiO2 or Li2O-SiO2-P2O5. Examples of lithium-containing metal nitrides are Li x P y O 1-z N z An example of a lithium-containing transition metal oxide is lithium titanium oxide.

[0093] As the solid electrolyte, only one of these materials may be used, or two or more of these materials may be used in combination.

[0094] The solid electrolyte layer 300 may include a solid electrolyte having lithium ion conductivity.

[0095] In addition to the solid electrolyte, the solid electrolyte layer 300 may contain a binding binder such as polyethylene oxide or polyvinylidene fluoride.

[0096] The solid electrolyte layer 300 may have a thickness of not less than 5 μm and not more than 150 μm.

[0097] The solid electrolyte material may be composed of an agglomerate of particles, or may be composed of a sintered structure.

[0098] (Second embodiment) The battery according to the second embodiment will be described below. The matters described in the first embodiment may be omitted as appropriate.

[0099] FIG. 2 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to a second embodiment.

[0100] Fig. 2(a) is a cross-sectional view of a battery 1100 according to the second embodiment. Fig. 2(b) is a plan view of the battery 1100 according to the second embodiment as seen from above in the z-axis direction. Fig. 2(a) shows a cross section taken along line II-II in Fig. 2(b).

[0101] As shown in FIG. 2, in the battery 1100, the thermistor 401 is in contact with not only the first electrode 100 but also the solid electrolyte layer 300.

[0102] According to the above configuration, heat generation can be detected even if first electrode 100 is a thin layer. Therefore, it becomes easier to prevent fire or smoke from occurring in battery 1100 that includes a thin electrode.

[0103] In the battery 1100 shown in FIG. 2, the thermistor 401 is in contact with the first current collector 110. The thermistor 401 is in contact with the first lead terminal 411 on the surface opposite to the surface in contact with the first current collector 110. The thermistor 401 has a structure that can measure the temperature throughout the thickness of the first electrode 100. Specifically, for example, the thermistor 401 is in contact with all thickness positions of the first electrode 100. This allows heat generation within the first electrode 100 to be sensed quickly and with high accuracy. Therefore, with the above configuration, deterioration of the characteristics or burnout of the battery 1100 can be suppressed, and the battery 1100 has high reliability.

[0104] Thermistor 401 only needs to be in contact with first electrode 100, and does not necessarily have to be in contact with first current collector 110. In other words, first active material layer 120 may be disposed between thermistor 401 and first current collector 110.

[0105] Thermistor 401 may be thicker than first active material layer 120 .

[0106] To improve the bonding between the first lead terminal 411 and the solid electrolyte layer 300, the main surface of the first lead terminal 411 may be provided with irregularities, for example, to increase the contact area. For example, the first lead terminal 411 may be made of a metal material (e.g., Cu) whose surface is roughened so that the height difference between the irregularities, i.e., the maximum height roughness Rz (JIS B 0601:2013), is on the order of several microns. To improve the bonding between the thermistor 401 and the first lead terminal 411, at least a portion of the surface of the first lead terminal 411 may be roughened to provide irregularities of, for example, 0.5 μm to 5 μm, as described for the first lead terminal 410 of the battery 1000 according to the first embodiment.

[0107] The lead-out region of the first lead-out terminal 411 may be perforated with, for example, anchor holes to enhance connection with the surroundings. The shape of the holes is not particularly limited and may be, for example, circular, elliptical, or rectangular. By perforating the first lead-out terminal 411 in this manner, the reliability of the battery 1100 against thermal cycles and the like can be improved.

[0108] (Third embodiment) The battery according to the third embodiment will be described below. The matters described in the above embodiments may be omitted as appropriate.

[0109] FIG. 3 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to a third embodiment.

[0110] Fig. 3(a) is a cross-sectional view of a battery 1200 according to the third embodiment. Fig. 3(b) is a plan view of the battery 1200 according to the third embodiment as viewed from above in the z-axis direction. Fig. 3(a) shows a cross section taken along line III-III in Fig. 3(b).

[0111] As shown in Fig. 3, the battery 1200 differs from the battery 1000 according to the first embodiment in that it includes multiple thermistors. As shown in Fig. 3, the battery 1200 includes two thermistors 400a and 400b in contact with the first electrode 100. The two thermistors 400a and 400b are disposed at different thickness positions of the first electrode 100. Furthermore, a first lead-out terminal 410a in contact with the thermistor 400a and first lead-out terminals 410b and 410c in contact with the thermistor 400b are provided. The thermistor 400a is in contact with the first current collector 110. The first current collector 110 also functions as a terminal for the thermistor 400a.

[0112] According to the above configuration, the temperature at different thickness positions within the first electrode 100 can be monitored with high responsiveness and accuracy. Furthermore, since multiple first lead terminals are provided, heat dissipation within the first electrode 100 is improved. As a result, the battery 1200 has high reliability.

[0113] The number of thermistors provided in the battery 1200 is not limited to two, but may be three or more.

[0114] (Fourth embodiment) A battery according to a fourth embodiment will be described below. The matters described in the above embodiments may be omitted as appropriate.

[0115] FIG. 4 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to a fourth embodiment.

[0116] Fig. 4(a) is a cross-sectional view of a battery 1300 according to the fourth embodiment. Fig. 4(b) is a plan view of the battery 1300 according to the fourth embodiment as viewed from above in the z-axis direction. Fig. 4(a) shows a cross section taken along line IV-IV in Fig. 4(b).

[0117] As shown in Fig. 4, the battery 1300 differs from the battery 1200 according to the third embodiment in that it includes a second lead-out terminal. As shown in Fig. 4, the battery 1300 includes first lead-out terminals 410a, 410b and a second lead-out terminal 412. The first lead-out terminals 410a, 410b extend toward a first side surface 1300a of the battery 1300. The second lead-out terminal 412 extends toward a second side surface 1300b of the battery 1300, which is different from the first side surface 1300a.

[0118] According to the above configuration, heat generated within the battery 1300 can be dispersed and released over a wider range. As a result, deterioration of the characteristics and abnormal heat generation of the battery 1300 are further suppressed. Therefore, the battery 1300 has high reliability.

[0119] To improve heat dissipation, the direction in which the second lead-out terminal 412 is led out may be opposite to the direction in which the first lead-out terminals 410a and 410b are led out. That is, the second side surface 1300b of the battery 1300 described above may be the surface facing the first side surface 1300a of the battery 1300.

[0120] (Fifth embodiment) Hereinafter, a battery according to a fifth embodiment will be described. The matters described in the above embodiments may be omitted as appropriate.

[0121] FIG. 5 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to a fifth embodiment.

[0122] Fig. 5(a) is a cross-sectional view of a battery 1400 according to a fifth embodiment. Fig. 5(b) is a plan view of the battery 1400 according to the fifth embodiment as viewed from above in the z-axis direction. Fig. 5(a) shows a cross section taken along line VV in Fig. 5(b).

[0123] 5, battery 1400 differs from battery 1000 according to the first embodiment in that the shape of the thermistor is different. Battery 1400 according to the fifth embodiment includes a thermistor 402 having a hollow frame shape. The hollow portion of the thermistor 402 is filled with a first active material layer 120. The first active material layer 120 filling the hollow portion of the thermistor 402 is in contact with the thermistor 402.

[0124] According to the above configuration, heat generated in the first active material layer 120 located in the hollow portion of thermistor 402 can be detected with high responsiveness and accuracy.

[0125] The hollow portion of the thermistor 402 may be located at the center of the first active material layer 120 in a plan view. This allows the thermistor 402 to be arranged so as to surround the center of the active material layer that is prone to heat generation. Furthermore, the contact area between the thermistor 402 and the first active material layer 120 is increased. As a result, heat generation can be detected with high responsiveness and accuracy. Therefore, the battery 1400 has high reliability.

[0126] The shape of the hollow portion of thermistor 402 does not have to be rectangular. Other examples of the shape of the hollow portion of thermistor 402 include a circle, a square, a polygon, a star, or a cross. Furthermore, the outer shape of the frame of thermistor 402 is not limited to a rectangle, and may be a circle, a square, a polygon, a star, a cross, or the like.

[0127] (Sixth embodiment) A battery according to a sixth embodiment will be described below. The matters described in the above embodiments may be omitted as appropriate.

[0128] FIG. 6 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to a sixth embodiment.

[0129] Fig. 6(a) is a cross-sectional view of a battery 1500 according to a sixth embodiment. Fig. 6(b) is a plan view of the battery 1500 as viewed from above in the z-axis direction. Fig. 6(a) shows a cross section taken along line VI-VI in Fig. 6(b).

[0130] As shown in Fig. 6, the battery 1500 differs from the battery 1000 according to the first embodiment in the locations where the thermistors are installed and the number of thermistors. As shown in Fig. 6, the battery 1500 includes four thermistors 400c. The four thermistors 400c are disposed at the four corners of the first electrode 100, respectively.

[0131] With the above configuration, the temperature inside the battery can be monitored while thermistor 400c protects the corners of the power generating element, which are prone to breakage. In other words, in addition to improving the resistance of battery 1500 to external stress, heat generated inside battery 1500 can be detected with high responsiveness and accuracy. Therefore, battery 1500 has high reliability.

[0132] 6, thermistors 400c are arranged at all four corners of first electrode 100, but this is not limiting. It is sufficient that thermistors 400c are arranged at at least one corner of first electrode 100.

[0133] Thermistors 400c may be arranged not only at the corners of first electrode 100 but also at the corners of second electrode 200.

[0134] The shape of the thermistor 400c is not particularly limited, and the shape of the thermistor 400c does not have to be rectangular.

[0135] When the battery 1500 includes multiple thermistors 400c, the multiple thermistors 400c may have different shapes and sizes.

[0136] Seventh embodiment A battery according to the seventh embodiment will be described below. The matters described in the above embodiments may be omitted as appropriate.

[0137] FIG. 7 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to a seventh embodiment.

[0138] Fig. 7(a) is a cross-sectional view of a battery 1600 according to a seventh embodiment. Fig. 7(b) is a plan view of the battery 1600 according to the seventh embodiment as seen from above in the z-axis direction. Fig. 7(a) shows a cross section taken along line VII-VII in Fig. 7(b).

[0139] 7, the battery 1600 differs from the battery 1000 according to the first embodiment in that it further includes a thermistor 403 in contact with the second electrode 200. The thermistor 403 is in contact with, for example, the second current collector 210 of the second electrode 200. Therefore, the second current collector 210 can also serve as a terminal for the thermistor 403. Furthermore, a lead-out terminal 412 in contact with the thermistor 403 is provided.

[0140] According to the above configuration, heat generation can be detected even when it occurs within second electrode 200. Therefore, the reliability of battery 1600 can be further improved.

[0141] The thermistor that can be used as the thermistor 403 in contact with the second electrode 200 is the same as the thermistor 400 described in the first embodiment. The thermistor 403 in contact with the second electrode 200 may have a different shape and size from the thermistor 400 in contact with the first electrode 100.

[0142] (Eighth embodiment) Hereinafter, a battery according to an eighth embodiment will be described. The matters described in the above embodiments may be omitted as appropriate.

[0143] FIG. 8 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to an eighth embodiment.

[0144] Fig. 8(a) is a cross-sectional view of a battery 1700 according to an eighth embodiment. Fig. 8(b) is a plan view of the battery 1700 according to the eighth embodiment as seen from above in the z-axis direction. Fig. 8(a) shows a cross section taken along line VIII-VIII in Fig. 8(b).

[0145] 8 , in addition to the configuration of the battery 1600 according to the seventh embodiment, the battery 1700 further includes a thermistor 404 in contact with the solid electrolyte layer 300. That is, the battery 1700 includes thermistors in contact with the first electrode 100, the second electrode 200, and the solid electrolyte layer 300. The battery 1700 also includes a lead-out terminal 413 in contact with the thermistor 404.

[0146] With the above configuration, even if heat is generated in any of the first electrode 100, the second electrode 200, and the solid electrolyte layer 300, the heat can be detected in the battery 1700. Furthermore, the number of heat dissipation paths is increased and the range of the paths is widened. Therefore, the battery 1700 has higher reliability.

[0147] (Ninth embodiment) A battery according to a ninth embodiment will be described below. The matters described in the above embodiments may be omitted as appropriate.

[0148] FIG. 9 is a cross-sectional view and a plan view showing a schematic configuration of a battery according to a ninth embodiment.

[0149] Fig. 9(a) is a cross-sectional view of a battery 1800 according to a ninth embodiment. Fig. 9(b) is a plan view of the battery 1800 according to the ninth embodiment as viewed from above in the z-axis direction. Fig. 9(a) shows a cross section taken along line IX-IX in Fig. 9(b).

[0150] As shown in FIG. 9, battery 1800 differs from battery 1000 according to the first embodiment in that the thermistor is a chip-type laminated thermistor 405, that is, in that a thermistor having a laminated structure is used.

[0151] According to the above configuration, the temperature inside the battery 1800 can be measured using a small thermistor. As a result, the thermistor can be used while suppressing its effect on the volumetric energy density of the battery 1800. Furthermore, by using the chip-type laminated thermistor 405, which has excellent weather resistance and bending resistance, a battery 1800 with a highly reliable built-in thermistor can be realized.

[0152] The multilayer thermistor 405 has a configuration in which a thermistor material is disposed between opposing electrodes. This allows the resistance value of the multilayer thermistor 405 to be controlled over a wide range by adjusting the overlapping area between the electrodes and the thermistor material and the distance between the electrodes. As a result, the multilayer thermistor 405 can be adjusted to a desired resistance value that is easy to measure and control.

[0153] The multilayer thermistor 405 may include internal electrodes. Like a multilayer ceramic capacitor, the internal electrodes have a laminated structure, allowing the resistance of the multilayer thermistor 405 to be controlled over a wider range. In this case, the internal electrodes can also be used to increase the number of heat dissipation paths. Therefore, this configuration can improve temperature measurement sensitivity (i.e., responsiveness and accuracy) and more effectively suppress characteristic degradation and abnormal heat generation.

[0154] As the laminated thermistor 405, for example, a known chip element of so-called 0603 size (0.6×0.3×0.3 mm) can be used.

[0155] The material of the laminated thermistor 405 is not particularly limited, but may be, for example, an Mn-Co-Ni-Cu based NTC thermistor material.

[0156] The material of the internal electrodes of the multilayer thermistor 405 may be, for example, Pd.

[0157] The internal electrodes of the multilayer thermistor 405 may have a thickness of, for example, 0.5 μm to 3 μm.

[0158] The electrodes of the multilayer thermistor 405 may be made of a material containing a glass component and Cu to strengthen the bond with the thermistor material. In this case, the glass component may be contained in a proportion of 0.1 to 5 mass % relative to the Cu. Furthermore, the electrodes of the multilayer thermistor 405 may be plated with Ni / Sn for solder mounting. In the Ni / Sn plating, the Ni thickness may be, for example, 0.5 to 5 μm, and the Sn thickness may be, for example, 1 to 10 μm. This allows electrical connection between the multilayer thermistor 405 and the current collector by solder melting.

[0159] The shape of the laminated thermistor 405 is not limited to the 0603 size. The shape of the laminated thermistor 405 may be, for example, 0402 (0.4 mm × 0.2 mm × 0.2 mm). The smaller the shape of the laminated thermistor 405, the less the impact on the volumetric capacitance density.

[0160] 9, the laminated thermistor 405 is disposed in the center of the first electrode 100. One of the electrodes of the laminated thermistor 405 (electrode 405a) is in contact with the first current collector 110 and is electrically connected by solder. A conductive resin may be used instead of solder for the connection. The other electrode (electrode 405b) may be drawn out to the side of the battery 1800 by a first lead-out terminal 410.

[0161] [Battery manufacturing method] The method for manufacturing a battery according to the present disclosure includes, for example, forming a temperature sensor, a lead terminal in contact with the temperature sensor, and a first active material layer on a first current collector to prepare a first electrode to which the temperature sensor is bonded; fabricating a second electrode; forming a solid electrolyte layer on at least one electrode selected from the group consisting of the first electrode and the second electrode; joining the first electrode and the second electrode such that the solid electrolyte is disposed therebetween; Includes.

[0162] The method for manufacturing the battery of the present disclosure will be described in more detail below. Here, as an example, a method for manufacturing the battery 1000 according to the first embodiment will be described.

[0163] In the following description, an example in which the first electrode 100 is a positive electrode and the second electrode 200 is a negative electrode will be described.

[0164] First, pastes to be used for printing the positive electrode active material layer, the negative electrode active material layer, and thermistor are prepared. As the solid electrolyte raw material used for the mixture of the positive electrode active material layer and the negative electrode active material layer, for example, a glass powder of Li2S-P2S5-based sulfide containing triclinic crystals as the main component and having an average particle size of about 10 μm is prepared. This glass powder has a density of, for example, 2 × 10 -3 S / cm to 3×10 -3 As the positive electrode active material, for example, a layered Li·Ni·Co·Al composite oxide (e.g., LiNi 0.8 Co 0.15 Al 0.05A powder of O2 is used. A paste for a positive electrode active material layer is prepared by dispersing a mixture containing the above-mentioned positive electrode active material and the above-mentioned glass powder in an organic solvent or the like. As the negative electrode active material, for example, powder of natural graphite having an average particle size of approximately 10 μm is used. A paste for a negative electrode active material layer is prepared by dispersing a mixture containing the above-mentioned negative electrode active material and the above-mentioned glass powder in an organic solvent or the like. As the thermistor material, for example, powder of an NTC thermistor made of a Mn-Ni-Cr-Al-based oxide semiconductor having an average particle size of 3 μm (for example, a resistivity of 1 kΩ·cm to 3 kΩ·cm and a B constant of 4000 K to 5000 K) is used. The thermistor paste is prepared by dispersing this in the above-mentioned organic solvent or the like.

[0165] Next, copper foils, for example, approximately 30 μm thick, are prepared as the positive electrode current collector layer and the negative electrode current collector layer. A thermistor paste is printed in a predetermined thickness and shape on one surface of the copper foil to be used as the positive electrode current collector layer by screen printing. The thermistor paste is dried at 80°C to 130°C. Next, the same copper foil as the positive electrode current collector is used as the thermistor's lead electrode, and a first lead terminal is placed from the main surface of the thermistor to one side of the battery. A positive electrode active material layer paste is further printed in a predetermined thickness and shape on the positive electrode current collector layer on which the thermistor and first lead electrode are arranged, and dried at 80°C to 130°C. Meanwhile, a negative electrode active material layer paste is printed in a predetermined thickness and shape on one surface of the copper foil to be used as the negative electrode current collector layer, and dried at 80°C to 130°C. Each paste is printed, for example, in a thickness of approximately 50 μm to 100 μm. In this way, a positive electrode is produced in which the thermistor, the first extraction electrode, and the positive electrode active material layer are formed on the positive electrode current collector, and a negative electrode is produced in which the negative electrode active material layer is formed on the negative electrode current collector.

[0166] Next, the mixture containing the glass powder is dispersed in an organic solvent or the like to prepare a paste for the solid electrolyte layer. The paste for the solid electrolyte layer is printed on the positive electrode and the negative electrode using a metal mask, for example, to a thickness of about 100 μm. Thereafter, the positive electrode and the negative electrode on which the paste for the solid electrolyte layer is printed, each containing a thermistor, are dried at 80°C to 130°C.

[0167] Next, the solid electrolyte printed on the positive electrode active material layer and the solid electrolyte printed on the negative electrode active material layer are stacked so as to be in contact with and face each other, and the stacked body is placed in, for example, a die mold having a rectangular outer shape.

[0168] Next, a 70 μm thick, 5×10 elastic modulus sheet was placed between the pressure die punch and the laminate. 6 An elastic sheet of about 300 MPa is inserted. With this configuration, pressure is applied to the laminate via the elastic sheet. The press mold is then heated to 50°C at a pressure of 300 MPa for 90 seconds. This completes a battery in which a positive electrode containing a thermistor, a solid electrolyte layer, and a negative electrode are stacked.

[0169] The method and order of manufacturing the battery are not limited to the above example.

[0170] In the above-described manufacturing method, the positive electrode active material layer paste, the thermistor paste, the negative electrode active material layer paste, and the solid electrolyte layer paste are applied by printing, but the present invention is not limited to this. Examples of printing methods that may be used include doctor blade printing, calendar printing, spin coating, dip coating, inkjet printing, offset printing, die coating, and spray printing.

[0171] While the battery of the present disclosure has been described above based on the embodiments, the present disclosure is not limited to these embodiments. As long as they do not deviate from the gist of the present disclosure, various modifications conceivable by those skilled in the art to the embodiments and other forms constructed by combining some of the components of the embodiments are also included in the scope of the present disclosure. [Industrial Applicability]

[0172] The battery according to the present disclosure can be used as a secondary battery such as an all-solid-state lithium-ion battery used in various electronic devices or automobiles, for example. [Explanation of symbols]

[0173] 100 1st electrode 110 First current collector 120 First active material layer 200 2nd electrode 210 Second current collector 220 Second active material layer 300 solid electrolyte layer 400, 401, 402, 403, 404 Thermistors 410, 411, 412, 413 Pull-out terminals

Claims

1. A first electrode; A second electrode; a solid electrolyte layer disposed between the first electrode and the second electrode; A temperature sensor; a first lead terminal; Equipped with the temperature sensor includes at least one selected from the group consisting of a thermistor and a resistance temperature detector, and is in contact with the first electrode; the first lead terminal is in contact with the temperature sensor; the first electrode includes a first current collector; the temperature sensor is in contact with the first current collector, The first current collector also serves as a terminal of the temperature sensor. battery.

2. the temperature sensor includes a thermistor; The thermistor has an active part whose electrical resistance changes with a change in temperature. The battery of claim 1 .

3. the operating portion is contained within the first electrode and is in contact with the first electrode; The battery of claim 2.

4. The thermistor is enclosed within the first electrode. The battery of claim 2.

5. The thermistor is disposed at the center of the first electrode. The battery of claim 4.

6. the thermistor is in contact with the first electrode and the solid electrolyte layer. The battery of claim 2.

7. The thermistor has a hollow frame shape. The battery of claim 2.

8. The thermistor has a laminated structure. The battery of claim 2.

9. The thermistor is a chip type. The battery of claim 2.

10. The thermistor comprises an internal electrode. The battery of claim 2.

11. The thermistor includes a ceramic material. The battery of claim 2.

12. The ceramic material is an oxide ceramic. The battery of claim 11.

13. The oxide ceramic is a transition metal oxide containing at least one selected from the group consisting of Ni, Mn, Co, and Fe. The battery of claim 12.

14. The thermistor is an NTC thermistor. The battery of claim 11.

15. The ceramic material contains a crystalline phase having a spinel structure as a main component.

15. The battery of claim 14.

16. Further provided with a second lead terminal, the second lead-out terminal is in contact with the temperature sensor and is led out in a direction different from that of the first lead-out terminal; The battery of claim 1 .

17. The temperature sensor is electrically connected to the first current collector. The battery of claim 1 .

18. The first electrode is a positive electrode.

18. The battery of any one of claims 1 to 17.

19. A method for manufacturing the battery of claim 1, comprising: forming a temperature sensor, a lead terminal in contact with the temperature sensor, and a first active material layer on a first current collector to fabricate a first electrode to which the temperature sensor is bonded; fabricating a second electrode; forming a solid electrolyte layer on at least one electrode selected from the group consisting of the first electrode and the second electrode; joining the first electrode and the second electrode such that the solid electrolyte layer is disposed therebetween; A method for manufacturing a battery, comprising:

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