Solid-state battery, composite current collector, method for manufacturing the same, and electric device

Abstract

The application provides a solid-state battery, a composite current collector, a preparation method of the composite current collector and an electric device. The solid-state battery comprises at least two electrode layers, wherein the current collector of at least one electrode layer is a composite current collector, the composite current collector comprises a metal conductive layer, a conductive aerogel layer and a thermistor material layer, the thermistor material layer comprises a positive temperature coefficient thermistor material, the conductive aerogel layer is arranged on the metal conductive layer, the thermistor material layer is located between the conductive aerogel layer and the metal conductive layer, or the thermistor material layer is located on the surface of the metal conductive layer away from the conductive aerogel layer, or the thermistor material layer is located on the surface of the conductive aerogel layer away from the metal conductive layer. The solid-state battery has improved energy density and safety performance.

Description

Technical Field

[0001] This application relates to the field of solid-state battery technology, and in particular to a solid-state battery, a composite current collector, a method for preparing the same, and an electrical device thereof. Background Technology

[0002] In recent years, the application scope of solid-state batteries has become increasingly wide, including but not limited to energy storage power systems in hydropower, thermal power, wind power, and solar power plants, as well as power tools, electric bicycles, electric motorcycles, electric cars, military equipment, and aerospace. Therefore, higher requirements have been placed on the energy density and safety performance of solid-state batteries. However, the energy density and safety performance of solid-state batteries currently need further improvement. Summary of the Invention

[0003] To achieve the above objectives, a solid-state battery, a composite current collector, a method for preparing the same, and an electrical device are provided that can improve energy density and safety performance.

[0004] The first aspect of this application provides a solid-state battery, including at least two electrode layers, wherein the current collector of at least one electrode layer is a composite current collector, the composite current collector including a metal conductive layer, a conductive aerogel layer and a thermistor material layer, the thermistor material layer including a thermistor material with a positive temperature coefficient, and the conductive aerogel layer disposed on the metal conductive layer.

[0005] The thermistor material layer is located between the conductive aerogel layer and the metal conductive layer, or the thermistor material layer is located on the surface of the metal conductive layer away from the conductive aerogel layer, or the thermistor material layer is located on the surface of the conductive aerogel layer away from the metal conductive layer.

[0006] In the aforementioned solid-state battery, at least one electrode layer uses a composite current collector. This composite current collector is formed by the synergistic combination of a metal conductive layer, a conductive aerogel layer, and a thermistor material layer. The metal conductive layer provides good conductivity and mechanical strength, while the conductive aerogel layer provides good conductivity and low density, enhancing the lightweight nature of the composite current collector and thus improving the battery's mass energy density. The thermistor material layer exhibits good conductivity at room temperature. When the battery temperature rises above a certain level, the resistance of the thermistor material in the thermistor material layer increases rapidly, blocking the electron path and interrupting the current, thereby suppressing further thermal runaway. Furthermore, while the temperature rises on the side containing the thermistor material layer, blocking the circuit, the conductive aerogel layer maintains its porous, low thermal conductivity characteristics within the solid-state battery, providing some heat insulation and inhibiting the spread and propagation of thermal runaway to a certain extent. This multi-layered synergistic effect improves the battery's mass energy density while reducing the risk of thermal runaway.

[0007] In some implementations, one or more of the following characteristics are satisfied:

[0008] (1) The porosity of the conductive aerogel layer is 80%~99.8%, and can be selected as 85%~99.8%;

[0009] (2) The density of the conductive aerogel layer is 0.003 g / cm³. 3 ~0.1g / cm 3 The option is 0.01 g / cm³. 3 ~0.05g / cm 3 ;

[0010] (3) The conductivity of the conductive aerogel layer is ≥30S / cm, and can be selected as 30S / cm~80S / cm.

[0011] Within this range, the porosity of the conductive aerogel layer provides excellent heat insulation.

[0012] In some implementations, one or more of the following characteristics are satisfied:

[0013] (1) The components of the conductive aerogel layer include one or more of carbon nanotubes, carbon aerogel, MXene, graphene and conductive polymers;

[0014] (2) The thickness of the conductive aerogel layer is 1μm~10μm, and can be selected as 2μm~10μm.

[0015] In some implementations, one or more of the following characteristics are satisfied:

[0016] (1) The conductivity of the thermistor material at 25℃ is 50S / cm~500S / cm;

[0017] (2) The Curie temperature of the thermistor material is 80°C~100°C.

[0018] Solid-state batteries can reach temperatures of 60°C. Therefore, the Curie temperature of the thermistor material used is 80°C~100°C. When the temperature of the solid-state battery exceeds this temperature, the resistance of the thermistor material increases sharply, which can block the circuit, cut off the current, and suppress further thermal runaway.

[0019] In some implementations, one or more of the following characteristics are satisfied:

[0020] (1) The thermistor material includes a matrix material doped with a metal element, wherein the matrix material includes a ceramic material; optionally, the metal element includes one or more of Y, La, Nb, Ta, Bi, Sb, Ru, Mn, Fe, Cu and Cr; optionally, the ceramic material includes one or more of barium titanate, strontium titanate, lead titanate, strontium carbonate, titanium dioxide, iron oxide and vanadium oxide;

[0021] (2) The thickness of the thermistor material layer is 0.1μm~10μm, and can be selected as 0.1μm~5μm.

[0022] In some implementations, one or more of the following characteristics are satisfied:

[0023] (1) The metal conductive layer includes a metal conductive layer of one of iron, copper, aluminum, nickel, titanium and silver or an alloy layer containing at least one of copper, aluminum, nickel, titanium and silver.

[0024] (2) The thickness of the metal conductive layer is 0.1μm~10μm, and can be selected as 0.1μm~5μm.

[0025] In some embodiments, the electrode layer further includes an electrode active layer disposed on at least one side of the composite current collector.

[0026] In some embodiments, the thermistor material layer is located between the conductive aerogel layer and the metal conductive layer, and the electrode active layer is at least located on the side of the metal conductive layer away from the thermistor material layer.

[0027] In some embodiments, in the composite current collector, the thermistor material layer and the metal conductive layer are sequentially stacked on both sides of the conductive aerogel layer in the thickness direction.

[0028] Optionally, an electrode active layer is provided on the side of the metal conductive layer away from the thermistor material layer on both sides of the conductive aerogel layer.

[0029] In some embodiments, the thermistor material layer is located on the surface of the metal conductive layer away from the conductive aerogel layer, and the electrode active layer is at least located on the side of the thermistor material layer away from the metal conductive layer.

[0030] In some embodiments, in the composite current collector, the conductive aerogel layer has the metal conductive layer and the thermistor material layer sequentially stacked on both sides of its thickness direction.

[0031] Optionally, an electrode active layer is provided on the side of the thermistor material layer away from the metal conductive layer on both sides of the conductive aerogel layer.

[0032] In some embodiments, the solid-state battery further includes an electrode connection terminal connected to the conductive aerogel layer of the composite current collector.

[0033] In some embodiments, the conductive aerogel layer of the composite current collector is led out as an electrode tab, and the electrode connection terminal is connected to the electrode tab.

[0034] In some embodiments, the thermistor material layer is located on the surface of the conductive aerogel layer away from the metal conductive layer, and the electrode active layer is at least located on the side of the thermistor material layer away from the conductive aerogel layer.

[0035] In some embodiments, in the composite current collector, the conductive metal layer has the conductive aerogel layer and the thermistor material layer sequentially stacked on both sides of its thickness direction.

[0036] Optionally, an electrode active layer is provided on the side of the thermistor material layer away from the conductive aerogel layer on both sides of the metal conductive layer.

[0037] In some embodiments, the solid-state battery further includes an electrode connection terminal connected to the metal conductive layer of the composite current collector.

[0038] In some embodiments, the metal conductive layer of the composite current collector is led out as an electrode tab, and the electrode connection terminal is connected to the electrode tab.

[0039] In some of these embodiments, the solid-state battery is a solid-state battery.

[0040] In some embodiments, the solid-state battery is an all-solid-state battery.

[0041] In a second aspect, this application provides a composite current collector comprising a metal conductive layer, a conductive aerogel layer, and a thermistor material layer, wherein the thermistor material layer comprises a thermistor material with a positive temperature coefficient; the thermistor material layer is located between the conductive aerogel layer and the metal conductive layer, or the conductive aerogel layer is located between the metal conductive layer and the thermistor material layer.

[0042] In some embodiments, the composite current collector is the composite current collector in the solid-state battery provided in the first aspect of this application.

[0043] A third aspect of this application provides a method for preparing a composite current collector, comprising the following steps:

[0044] A stacked structure is formed comprising a metal conductive layer, a conductive aerogel layer, and a thermistor material layer; wherein the thermistor material layer comprises a thermistor material with a positive temperature coefficient; the thermistor material layer is located between the conductive aerogel layer and the metal conductive layer, or the conductive aerogel layer is located between the metal conductive layer and the thermistor material layer.

[0045] In a fourth aspect, this application provides an electrical device comprising at least one of the solid-state battery described in the first aspect of this application, the composite current collector provided in the second aspect of this application, and the composite current collector prepared by the preparation method provided in the third aspect of this application.

[0046] The power supply device of this application includes the solid-state battery provided in this application, and therefore has at least the same advantages as the solid-state battery.

[0047] Details of one or more embodiments of this application are set forth in the following drawings and description. Other features, objects, and advantages of this application will become apparent from the specification, drawings, and claims. Attached Figure Description

[0048] To better describe and illustrate the embodiments or examples provided in this application, reference may be made to one or more accompanying drawings. Additional details or examples used to describe the drawings should not be considered as limiting the scope of any of the disclosed applications, the currently described embodiments or examples, or the best mode of conduct of these applications as currently understood. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0049] Figure 1 This is a cross-sectional schematic diagram of a solid-state battery cell according to one embodiment of this application.

[0050] Figure 2 This is a schematic diagram of the cross-sectional structure of the composite current collector used in a solid-state battery cell according to an embodiment of this application.

[0051] Figure 3 This is a schematic diagram of the cross-sectional structure of the composite current collector used in a solid-state battery cell according to another embodiment of this application.

[0052] Figure 4 This is a schematic diagram of the cross-sectional structure of the composite current collector used in a solid-state battery cell according to another embodiment of this application.

[0053] Figure 5 This is a three-dimensional structural diagram of a solid-state battery cell according to an embodiment of this application.

[0054] Figure 6 for Figure 5 An exploded view of a solid-state battery cell according to an embodiment of this application is shown.

[0055] Figure 7 This is a schematic diagram of a battery device according to one embodiment of this application.

[0056] Figure 8 This is a schematic diagram of a battery pack according to one embodiment of this application.

[0057] Figure 9 for Figure 8 An exploded view of a battery pack according to one embodiment of this application is shown.

[0058] Figure 10 This is a schematic diagram of an electrical device that uses a solid-state battery as a power source according to one embodiment of this application.

[0059] Explanation of reference numerals in the attached figures:

[0060] 1. Battery pack; 2. Upper casing; 3. Lower casing; 4. Battery assembly; 5. Solid-state battery cell; 51. Casing; 52. Solid-state cell; 521. Positive electrode layer; 5211. Positive electrode current collector; 5212. Positive electrode active layer; 522. Solid electrolyte layer; 523. Negative electrode layer; 5231. Negative electrode current collector; 5232. Negative electrode active layer; 53. Cover plate; 6. Electrical device; 7. Composite current collector; 71. Metal conductive layer; 72. Conductive aerogel layer; 73. Thermistor material layer. Detailed Implementation

[0061] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0062] The "range" disclosed in this application can be defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints; any endpoint can be independently included or excluded, and they can be combined arbitrarily, meaning any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values ​​1 and 2 are listed, and maximum range values ​​3, 4, and 5 are also listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this document; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, stating that a parameter is an integer ≥2 is equivalent to disclosing that the parameter is, for example, an integer 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc. For instance, stating that a parameter is an integer selected from "2-10" is equivalent to listing the integers 2, 3, 4, 5, 6, 7, 8, 9, and 10.

[0063] In this application, the terms "multiple" or "various" are used unless otherwise specified, referring to a quantity greater than or equal to 2. For example, "one or more" means one or more types.

[0064] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0065] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment or implementation of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments. The term "implementation" as used herein has a similar understanding.

[0066] Those skilled in the art will understand that the order in which the steps are written in the methods of various embodiments or examples does not imply a strict execution order and does not constitute any limitation on the implementation process. The detailed execution order of each step should be determined by its function and possible internal logic. Unless otherwise specified, all steps of this application may be performed sequentially or randomly, preferably sequentially. For example, if the method includes steps (a) and (b), it means that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, if the method may also include step (c), it means that step (c) can be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0067] In this application, unless otherwise specified, A (e.g., B) means that B is a non-limiting example of A, and it is understood that A is not limited to B.

[0068] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it means that it is selected from either "with" or "without." If there are multiple "optional" entries in a technical solution, unless otherwise specified and there are no contradictions or mutual constraints, each "optional" entry shall be independent.

[0069] The mass energy density of a battery refers to the energy that can be stored per unit mass of battery, usually expressed in watt-hours per kilogram (Wh / kg). It directly relates to the battery's range and application scope. Heat generation is unavoidable during battery operation, making thermal management crucial for battery safety. However, the energy density and safety performance of solid-state batteries currently require further improvement.

[0070] Based on this, according to various embodiments and examples of this application, this application provides at least one solid-state battery, a composite current collector, a method for preparing the same, and an electrical device thereof. This solid-state battery exhibits improved energy density and safety performance.

[0071] Unless otherwise specified, the term "solid-state battery" in this application refers to a battery in which the electrolyte includes a solid electrolyte. Typically, a solid-state battery includes a positive electrode layer, a solid electrolyte layer, and a negative electrode layer. The solid electrolyte layer is located between the positive and negative electrode layers. During charging and discharging, active ions repeatedly insert and extract between the positive and negative electrode layers. The solid electrolyte layer acts as a conductor of ions between the positive and negative electrode layers and also isolates them, preventing short circuits. Therefore, a separator, as found in traditional lithium-ion batteries, is not required in solid-state batteries. Solid-state batteries use a non-flammable solid electrolyte instead of the organic electrolyte in traditional liquid lithium-ion batteries, significantly improving battery safety. In addition to improved safety, solid-state batteries are better suited for high-energy-density positive and negative electrode materials and reduce system weight, which is beneficial for achieving higher energy density.

[0072] Solid-state batteries include semi-solid-state batteries and all-solid-state batteries. In some implementations, solid-state batteries are all-solid-state batteries. Liquid batteries are batteries in which the electrolyte is liquid. Semi-solid-state batteries are a type of battery between liquid batteries and all-solid-state batteries, mainly based on liquid batteries, where part of the electrolyte is replaced with a solid electrolyte.

[0073] In this application, unless otherwise specified, "all-solid-state battery" refers to a solid-state battery in which all electrolytes are solid electrolytes. In this case, the positive electrode layer, negative electrode layer and electrolyte part are all made of solid materials, and no liquid electrolyte is provided in the battery, so it can be called "all-solid-state battery".

[0074] A solid-state battery includes at least one solid-state battery cell (i.e., a solid-state battery cell). A solid-state battery may include one or more solid-state battery cells.

[0075] In this application, unless otherwise specified, "solid-state battery cell" refers to the basic unit capable of converting chemical energy into electrical energy, and all its components are solid-state. For non-limiting purposes, please refer to [link to relevant documentation]. Figure 1 The solid-state battery cell 52 may include a positive electrode layer 521, a solid electrolyte layer 522, and a negative electrode layer 523, with the solid electrolyte layer 522 located between the positive electrode layer 521 and the negative electrode layer 523. During battery charging and discharging, active ions shuttle between the positive and negative electrode layers, inserting and extracting. The solid electrolyte layer acts as a conductor of ions between the positive and negative electrode layers and also isolates the positive and negative electrode layers, thus preventing short circuits between the positive and negative electrodes.

[0076] Furthermore, the positive electrode layer 521, the solid electrolyte layer 522, and the negative electrode layer 523 can constitute a battery cell; understandably, the solid-state cell 52 also includes multiple battery cells stacked on top of each other, see [link to relevant documentation]. Figure 1As an example, it only shows three battery cells stacked together along the thickness direction; however, the actual number can be set to one or more as needed. See also Figure 1 As an example, the positive electrode layer 521 includes a positive electrode current collector 5211 and a positive electrode active layer 5212 disposed on at least one surface of the positive electrode current collector 5211. As an example, the negative electrode layer 523 includes a negative electrode current collector 5231 and a negative electrode active layer 5232 disposed on at least one surface of the negative electrode current collector 5231.

[0077] In some implementations, the solid-state battery cell can be an all-solid-state battery cell.

[0078] In this application, unless otherwise specified, "all-solid-state battery cell" refers to a solid-state battery cell in which all electrolytes are solid electrolytes. In this case, the positive electrode layer, negative electrode layer and electrolyte part are all made of solid materials, and no liquid electrolyte is provided in the battery cell, so it can be called "all-solid-state battery cell".

[0079] In this application, unless otherwise specified, "solid electrolyte" refers to an electrolyte material or substance that exists in solid form during the storage and fabrication of solid-state batteries and their components, as well as during the operation of solid-state batteries. This includes, but is not limited to, solid electrolytes existing in solid form at room temperature.

[0080] In this application, unless otherwise specified, "electrode layer" includes electrode active material. The electrode layer can be a positive electrode layer or a negative electrode layer. "Electrode active material" in the electrode layer refers to a material capable of reversibly inserting and extracting active ions. Unless otherwise specified, "negative electrode active material" refers to a material used in the negative electrode layer capable of reversibly inserting and extracting active ions; "positive electrode active material" refers to a material used in the positive electrode layer capable of reversibly extracting and inserting active ions. During solid-state battery charging, active ions are extracted from the positive electrode, pass through the solid electrolyte layer, and insert into the negative electrode; while during solid-state battery discharging, active ions are extracted from the negative electrode and insert into the positive electrode. The active ions are not particularly limited or restrictive; they can be lithium ions, corresponding to a lithium-ion solid-state battery.

[0081] In this application, unless otherwise specified, "electrode active layer" includes at least one of the positive active layer in the positive electrode layer and the negative active layer in the negative electrode layer. Depending on the specific circumstances, the electrode active layer may refer to either the positive active layer or the negative active layer. It is understood that the positive active layer contains a positive active material, and the negative active layer contains a negative active material.

[0082] In a first aspect, one embodiment of this application provides a solid-state battery with at least two electrode layers, wherein the current collector of at least one electrode layer is a composite current collector.

[0083] The composite current collector includes a metal conductive layer, a conductive aerogel layer, and a thermistor material layer. The thermistor material layer includes a positive temperature coefficient thermistor material (PTC material), and the conductive aerogel layer is disposed on the metal conductive layer.

[0084] In this configuration, the thermistor material layer is located between the conductive aerogel layer and the metal conductive layer; or, the thermistor material layer is located on the surface of the metal conductive layer away from the conductive aerogel layer; or, the thermistor material layer is located on the surface of the conductive aerogel layer away from the metal conductive layer.

[0085] Positive Temperature Coefficient (PTC) thermistor materials are semiconductor materials that exhibit a positive temperature coefficient effect, meaning their resistivity increases with increasing temperature. At lower temperatures, the resistance of PTC materials remains relatively constant within a certain range. However, when the temperature reaches a specific value, namely the Curie temperature, its resistance increases dramatically with increasing temperature. Typically, within a very small temperature range, the resistance can rapidly increase to 10 times its original value. 3 ~10 5 times.

[0086] The conductive aerogel layer not only possesses electrical conductivity but also provides excellent thermal insulation due to its porous structure. Specifically, when the battery is operating normally, the resistance of the thermistor material layer is low; however, when the battery temperature rises abnormally, the resistance of the thermistor material layer increases dramatically, effectively blocking the circuit as if it were an open circuit. At this point, the conductive aerogel layer cannot perform its conductivity but can still provide thermal insulation, working synergistically with the thermistor material layer to reduce the risk of thermal runaway.

[0087] In the aforementioned solid-state battery, at least one electrode layer uses a composite current collector. This composite current collector is formed by the synergistic combination of a metal conductive layer, a conductive aerogel layer, and a thermistor material layer. The metal conductive layer provides good conductivity and mechanical strength, while the conductive aerogel layer provides good conductivity and low density, enhancing the lightweight nature of the composite current collector and thus improving the battery's mass energy density. The thermistor material layer exhibits good conductivity at room temperature. When the battery temperature rises above a certain level, the resistance of the thermistor material in the thermistor material layer increases rapidly, blocking the electron path and interrupting the current, thereby suppressing further thermal runaway. Furthermore, while the temperature rises on the side containing the thermistor material layer, blocking the circuit, the conductive aerogel layer maintains its porous, low thermal conductivity characteristics within the solid-state battery, providing some heat insulation and inhibiting the spread and propagation of thermal runaway to a certain extent. This multi-layered synergistic effect improves the battery's mass energy density while reducing the risk of thermal runaway.

[0088] When the aforementioned composite current collector is applied to solid-state batteries, especially all-solid-state batteries, compared to liquid battery systems, the pores of its conductive aerogel layer are not easily or not filled by the electrolyte, thus facilitating the effective performance of its heat insulation function.

[0089] Understandably, the electrode layer can be either a positive electrode layer or a negative electrode layer. In a solid-state battery, at least two electrode layers are present, one of which is a positive electrode layer and the other is a negative electrode layer. In other words, the aforementioned solid-state battery includes a positive electrode layer and a negative electrode layer, and the current collector for at least one of the positive and negative electrode layers is the aforementioned composite current collector. Further, the aforementioned solid-state battery may include one or more positive electrode layers, and may also include one or more negative electrode layers, wherein all or part of the positive electrode layer may use the aforementioned composite current collector, and all or part of the negative electrode layer may use the aforementioned composite current collector. Understandably, when some current collectors do not use the aforementioned composite current collector, current collector materials known in the art may also be used.

[0090] Optionally, each positive electrode layer or each negative electrode layer may employ the aforementioned composite current collector. Optionally, each electrode layer may employ the aforementioned composite current collector.

[0091] In some embodiments, the porosity of the conductive aerogel layer is 80% to 99.8%. As an example, the porosity of the conductive aerogel layer can be 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 99.8%, or a range defined by any two of the above values ​​as endpoints. Within this range, the porosity of the conductive aerogel layer provides superior heat insulation. Further, the porosity of the conductive aerogel layer is 85% to 99%.

[0092] In some embodiments, the density of the conductive aerogel layer is 0.003 g / cm³. 3 ~0.1g / cm 3 The option is 0.01 g / cm³. 3 ~0.05g / cm 3 As an example, the density of the conductive aerogel layer can be 0.003 g / cm³. 3 0.005g / cm 3 0.008g / cm 3 0.01g / cm 3 0.02g / cm 3 0.05g / cm 3 0.08g / cm 3 0.1g / cm 3 , or the range formed by any two of the above point values ​​as endpoints.

[0093] In some embodiments, the conductivity of the conductive aerogel layer is ≥30 S / cm, optionally ranging from 30 S / cm to 80 S / cm. As an example, the conductivity of the conductive aerogel layer can be 30 S / cm, 35 S / cm, 40 S / cm, 45 S / cm, 50 S / cm, 55 S / cm, 60 S / cm, 65 S / cm, 70 S / cm, 75 S / cm, or 80 S / cm, or within a range defined by any two of the above values ​​as endpoints.

[0094] In some embodiments, the conductive aerogel layer comprises one or more of carbon nanotubes, carbon aerogel, MXene, graphene, and conductive polymers. The conductive aerogel layer may be formed from one of the above materials, or from multiple of the above materials.

[0095] As an example, the conductive aerogel layer includes a stack formed from one or more of the following: carbon nanotube aerogel layer, carbon aerogel, MXene aerogel layer, graphene aerogel layer, conductive polymer aerogel layer, and MXene / C aerogel.

[0096] MXene / C aerogels can be constructed by combining MXene nanosheets with polyacrylonitrile (PAN) nanofibers and then constructing a three-dimensional network structure of C aerogels through the carbonization process of PAN.

[0097] In some embodiments, the thickness of the conductive aerogel layer is 1 μm to 10 μm, optionally 2 μm to 10 μm. As an example, the thickness of the conductive aerogel layer can be 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, or within the range formed by any two of the above point values ​​as endpoints.

[0098] In some embodiments, the thermistor material has a conductivity of 50 S / cm to 500 S / cm at 25°C, which can be selected as 50 S / cm, 100 S / cm, 120 S / cm, 150 S / cm, 200 S / cm, 250 S / cm, 300 S / cm, 350 S / cm, 400 S / cm, 450 S / cm, 500 S / cm, or any two of the above values ​​as end values.

[0099] In some embodiments, the Curie temperature of the thermistor material is 80°C to 100°C, optionally selected as 80°C, 85°C, 90°C, 95°C, or 100°C, or any two of the above values ​​as endpoints. The temperature of a solid-state battery can reach 60°C. Therefore, using a thermistor material with a Curie temperature of 80°C to 100°C ensures that when the temperature of the solid-state battery exceeds this temperature, the resistance of the thermistor material increases sharply, effectively blocking the circuit, cutting off the current, and suppressing further thermal runaway.

[0100] In some embodiments, the thermistor material comprises a matrix material doped with a metal element. The matrix material includes a ceramic material. Optionally, the metal element includes one or more of Y, La, Nb, Ta, Bi, Sb, Ru, Mn, Fe, Cu, and Cr; optionally, the ceramic material includes one or more of barium titanate, strontium titanate, lead titanate, strontium carbonate, titanium dioxide, iron oxide, and vanadium oxide.

[0101] Furthermore, the metal element is doped into the matrix material as an oxide of the metal element. Furthermore, the thermistor material also includes additives, which include one or more of silicon oxide and aluminum oxide. The additives are mixed with the matrix material doped with the metal element, forming a glassy phase. This glassy phase can absorb impurities, improve the purity and performance of the material, and also improve the sintering performance of the material, promote grain growth, and make the material more compact, thereby improving the electrical performance and stability of the PTC material.

[0102] As an example, thermistor materials include, but are not limited to, Cu2O-doped barium titanate.

[0103] In some embodiments, the thickness of the thermistor material layer is 0.1 μm to 10 μm, optionally 0.1 μm to 5 μm. As an example, the thickness of the thermistor material layer can be 0.1 μm, 0.2 μm, 0.5 μm, 0.8 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, or within the range defined by any two of the above values ​​as endpoints.

[0104] In some embodiments, the metallic conductive layer comprises a metallic conductive layer of one of iron, copper, aluminum, nickel, titanium, and silver, or an alloy layer containing at least one of copper, aluminum, nickel, titanium, and silver. Understandably, the metallic conductive layer is generally an elemental metal or a metal layer, possessing good conductivity and density, thus providing good mechanical strength. Generally, the porosity of the metallic conductive layer can be 0-50%, more specifically 0-10%, or 0-5%.

[0105] In some embodiments, the thickness of the metal conductive layer is 0.1 μm to 10 μm, and can be selected as 0.1 μm to 5 μm. As an example, the thickness of the metal conductive layer can be 0.1 μm, 0.2 μm, 0.5 μm, 0.8 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, or within the range formed by any two of the above point values ​​as end values.

[0106] In some embodiments, the electrode layer further includes an electrode active layer disposed on at least one side of the composite current collector.

[0107] In some embodiments, if the electrode layer is a positive electrode layer, then the corresponding electrode active layer is a positive electrode active layer, and the corresponding current collector is a positive electrode current collector.

[0108] In some embodiments, if the electrode layer is a negative electrode layer, then the corresponding electrode active layer is a negative electrode active layer, and the corresponding current collector is a negative electrode current collector.

[0109] In some embodiments, the thermistor material layer is located between the conductive aerogel layer and the metal conductive layer. In other words, the composite current collector includes a stacked metal conductive layer, a thermistor material layer, and a conductive aerogel layer. In this case, the electrode active layer is at least located on the side of the metal conductive layer away from the thermistor material layer. Furthermore, the thermistor material layer and the conductive aerogel layer can be in direct contact to allow the conductive aerogel layer to utilize its porous, low thermal conductivity properties and improve its heat insulation effect. It is understood that in other examples, other layers may also be provided between the thermistor material layer and the conductive aerogel layer.

[0110] When an abnormal heat occurs inside one of the battery cells, causing a temperature rise, the heat is conducted to the composite current collector of that cell. The resistance of the thermistor material in the thermistor material layer increases rapidly, blocking the electron path and interrupting the current, thus inhibiting further thermal runaway. The conductive aerogel layer located on one side of the thermistor material layer can then better utilize its porous, low thermal conductivity properties to insulate against heat, inhibiting heat diffusion to the other side of the composite current collector. This reduces the damage to the battery cell caused by thermal runaway, and adjacent battery cells may even function normally if the temperature rise is not significant. In other words, it is possible to block the current path of a single thermally runaway battery cell without affecting other normal battery cells.

[0111] Furthermore, in the composite current collector, a thermistor material layer and a metal conductive layer are sequentially stacked on both sides of the conductive aerogel layer in the thickness direction. In other words, the composite current collector includes a stacked metal conductive layer, a thermistor material layer, a conductive aerogel layer, a thermistor material layer, and a metal conductive layer.

[0112] The thermistor material layers on both sides of the conductive aerogel layer can quickly sense the thermal anomalies of the corresponding battery cells, improve their sensitivity to blocking electronic pathways, reduce the damage to the battery caused by thermal runaway, and improve the battery's safety performance while also enhancing its protection performance.

[0113] Optionally, the electrode active layer is disposed on the metal conductive layer on the outside of the composite current collector. More preferably, the electrode active layer is disposed on the side of the metal conductive layer away from the thermistor material layer on both sides of the conductive aerogel layer. That is, the two electrode active layers are disposed on the metal conductive layers on both sides of the composite current collector in its thickness direction.

[0114] In some embodiments, the thermistor material layer is located between the conductive aerogel layer and the metal conductive layer; the solid-state battery also includes electrode connection terminals connected to the conductive aerogel layer of the composite current collector.

[0115] Furthermore, the conductive aerogel layer of the composite current collector is led out as an electrode tab, and the electrode connection terminal is connected to the electrode tab. Understandably, the electrode connection terminal can be directly or indirectly connected to the electrode tab. Since the conductive aerogel layer serves as the lead-out layer for the electrode tab and also possesses certain thermal insulation properties, when the resistance of either of the thermistor material layers on both sides of the conductive aerogel layer increases, blocking the corresponding battery cell's path, the conductive aerogel layer can still provide thermal insulation for the other battery cell.

[0116] Please see Figure 2 As an example, the composite current collector 7 includes a stacked metal conductive layer 71, a thermistor material layer 73, a conductive aerogel layer 72, and the metal conductive layer 71. The conductive aerogel layer 72 extends out as an electrode tab 74, and an electrode connection terminal is connected to the electrode tab 74. An electrode active layer may be disposed on the metal conductive layer 71.

[0117] Understandably, a solid-state battery includes two electrode connection terminals, one positive and one negative. The solid-state battery includes an outer packaging, with electrode plates disposed within the outer packaging and the electrode connection terminals disposed on the outer packaging. The positive electrode layer has a positive electrode tab, and the negative electrode layer has a negative electrode tab. The positive electrode layer is connected to the positive terminal, and the negative electrode tab is connected to the negative electrode terminal.

[0118] In other embodiments, the thermistor material layer is located on the surface of the metal conductive layer away from the conductive aerogel layer. In other words, the composite current collector includes a stacked thermistor material layer, a metal conductive layer, and a conductive aerogel layer. In this case, the electrode active layer is at least located on the side of the thermistor material layer away from the metal conductive layer. The structure of this composite current collector is the same as described above. Figure 2The structures shown are similar, differing only in that the positions of the thermistor material layer and the metal conductive layer are interchanged, achieving similar technical effects, which will not be elaborated further here; the selection of materials for each layer and the thickness range are also similar. Furthermore, in the composite current collector, the conductive aerogel layer has a metal conductive layer and a thermistor material layer sequentially stacked on both sides of its thickness direction. In other words, the composite current collector includes a stacked thermistor material layer, a metal conductive layer, a conductive aerogel layer, another metal conductive layer, and a thermistor material layer. Further, the conductive aerogel layer of the composite current collector is led out as an electrode tab.

[0119] Please see Figure 3 As an example, the composite current collector 7 includes a thermistor material layer 73, a metal conductive layer 71, and a conductive aerogel layer 72, all stacked together. The conductive aerogel layer 72 extends out as an electrode tab 74, and an electrode connection terminal is connected to the electrode tab 74. An electrode active layer may be disposed on the metal conductive layer 71.

[0120] In other embodiments, the thermistor material layer is located on the surface of the conductive aerogel layer away from the metal conductive layer, i.e., the conductive aerogel layer is located between the metal conductive layer and the thermistor material layer. In other words, the composite current collector includes a stacked thermistor material layer, a conductive aerogel layer, and a metal conductive layer. In this case, the electrode active layer is at least located on the side of the thermistor material layer away from the conductive aerogel layer. Furthermore, the thermistor material layer and the conductive aerogel layer are in direct contact to allow the conductive aerogel layer to utilize its porous, low thermal conductivity properties and improve its heat insulation effect. It is understood that in other examples, other layers may also be provided between the thermistor material layer and the conductive aerogel layer.

[0121] When an abnormal heat occurs inside one of the battery cells, causing a temperature rise, the heat is conducted to the composite current collector of that cell. The resistance of the thermistor material in the thermistor material layer increases rapidly, blocking the electron path and interrupting the current, thus inhibiting further thermal runaway. At this time, the conductive aerogel layer located on one side of the thermistor material layer can better utilize its porous and low thermal conductivity characteristics to play a certain role in heat insulation, inhibiting the diffusion of heat to the other side of the composite current collector. This can reduce the damage to the battery cell caused by thermal runaway, and even allow adjacent battery cells to operate normally when the temperature rise of adjacent battery cells is not large.

[0122] Furthermore, in the composite current collector, conductive aerogel layers and thermistor material layers are sequentially stacked on both sides of the metal conductive layer in the thickness direction. In other words, the composite current collector includes a stacked thermistor material layer, a conductive aerogel layer, a metal conductive layer, a conductive aerogel layer, and a thermistor material layer.

[0123] The thermistor material layers on both sides of the conductive aerogel layer can quickly sense the thermal anomalies of the corresponding battery cells, improve their sensitivity to blocking electronic pathways, reduce the damage to the battery caused by thermal runaway, and improve the battery's safety performance while also enhancing its protection performance.

[0124] Optionally, the electrode active layer is disposed on the thermistor material layer outside the composite current collector. More preferably, the electrode active layer is disposed on the side of the thermistor material layer away from the conductive aerogel layer on both sides of the metal conductive layer. That is, the two electrode active layers are disposed on the thermistor material layers on both sides of the composite current collector in its thickness direction.

[0125] In some embodiments, the conductive aerogel layer is located between the metal conductive layer and the thermistor material layer; the solid-state battery also includes electrode connection terminals, which are connected to the metal conductive layer of the composite current collector.

[0126] Furthermore, the metallic conductive layer of the composite current collector is led out as an electrode tab, and the electrode connection terminal is connected to the electrode tab. Understandably, the electrode connection terminal can be directly or indirectly connected to the electrode tab. The metallic conductive layer has good mechanical strength, making it easier to lead out the electrode tab.

[0127] Please see Figure 4 As an example, the composite current collector 7 includes a thermistor material layer 73, a conductive aerogel layer 72, a metal conductive layer 71, a conductive aerogel layer 72, and a thermistor material layer 73 stacked together. The metal conductive layer 71 of the composite current collector 7 extends out as an electrode tab 74, and an electrode connection terminal is connected to the electrode tab 74.

[0128] The positive electrode layer can be provided by a pre-fabricated positive electrode sheet or by a positive electrode sheet that is available in the art for use in solid-state batteries.

[0129] Positive electrode sheets can be prepared using dry or wet methods. For example, they can be dry-pressed into films. Alternatively, they can be wet-coated and dried to form films.

[0130] In some embodiments, the positive electrode layer includes a positive electrode current collector and a positive electrode active layer disposed on at least one surface of the positive electrode current collector.

[0131] Unless otherwise stated, the positive electrode layer in this application includes at least a positive electrode active layer.

[0132] Unless otherwise stated in this application, the positive electrode sheet includes at least a positive active layer.

[0133] In this application, unless otherwise specified, the positive electrode active layer includes at least positive electrode active particles, and usually also includes positive electrode electrolyte particles.

[0134] In this application, unless otherwise specified, "positive electrode active particles" refers to particles containing positive electrode active substances that have the ability to reversibly extract and insert active ions.

[0135] In this application, unless otherwise specified, "positive electrode electrolyte particles" and "positive electrode solid electrolyte" have the same meaning and can be used interchangeably, referring to solid electrolytes that can be used in the positive electrode layer. Positive electrode electrolyte particles can enhance the ion conductivity of the positive electrode layer, reduce interfacial impedance, and promote the charge transfer efficiency and full release of capacity between the positive electrode active material and the external environment.

[0136] In some embodiments, the positive electrode active material may be a known positive electrode active material for batteries. As a non-limiting example, the positive electrode active material may include one or more of the following materials: lithium-containing phosphates with an olivine structure, lithium transition metal oxides, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium transition metal oxides include, but are not limited to, one or more of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, and their modified compounds. Non-limiting examples of lithium-containing phosphates with an olivine structure include, but are not limited to, one or more of lithium iron phosphate, lithium iron phosphate and carbon composites, lithium manganese phosphate, lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium manganese iron phosphate and carbon composites. Non-limiting examples of lithium cobalt oxides may include LiCoO2; non-limiting examples of lithium nickel oxides may include LiNiO2; non-limiting examples of lithium manganese oxides may include LiMnO2, LiMn2O4, etc.; non-limiting examples of lithium nickel cobalt manganese oxides may include LiNi 1 / 3 Co 1 / 3Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn0.1 O2 (also known as NCM) 811 Examples of lithium nickel cobalt aluminum oxides include LiNi, etc. 0.80 Co 0.15 Al 0.05 O2. Examples of lithium iron phosphate include LiFePO4 (also known as LFP). Examples of lithium manganese phosphate include LiMnPO4.

[0137] Without limitation, the weight percentage of positive electrode active particles or positive electrode active materials in the positive electrode active layer can be ≥70wt%, further ≥80wt%, even further ≥90wt%, and can also be 70wt%~99wt%, optionally 80wt%~95wt%, as an example.

[0138] Non-limiting, the weight percentage of positive electrode electrolyte particles in the positive electrode active layer can be 0.1wt% to 30wt%, and optionally 5wt% to 20wt%.

[0139] In some embodiments, the positive electrode active layer includes positive electrode electrolyte particles. Non-limitingly, the weight percentage of the positive electrode electrolyte particles in the positive electrode active layer can be 0.1 wt% to 30 wt%, optionally 5 wt% to 20 wt%.

[0140] In some embodiments, the positive electrode active layer includes positive electrode active particles and positive electrode electrolyte particles.

[0141] In some embodiments, the positive electrode active layer includes a conductive agent (which may be referred to as a positive electrode conductive agent). As a non-limiting example, the positive electrode conductive agent may be a carbon conductive agent. Non-limitingly, the carbon conductive agent may include one or more of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers. In some embodiments, the positive electrode conductive agent may include, but is not limited to, one or more of SP, KS-6, acetylene black, branched Ketjen black ECP, SFG-6, vapor-grown carbon fiber VGCF, carbon nanotubes (CNTs), and graphene. Non-limitingly, the weight percentage of the positive electrode conductive agent in the positive electrode active layer may be 0-10 wt%, more further 0-8 wt%, even further 0-5 wt%, and even further 0.1 wt%-3 wt%. When the positive electrode material is prepared into a positive electrode active layer using a dry method, the positive electrode conductive agent can be incorporated into the positive electrode material, which can improve the conductivity of the positive electrode active layer.

[0142] In some embodiments, the positive electrode active layer optionally includes a binder (which may be referred to as a positive electrode binder). As a non-limiting example, the positive electrode binder may include one or more of polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), PVDF-tetrafluoroethylene-propylene terpolymer, PVDF-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene copolymer, and fluorinated acrylate resins. The aforementioned non-limiting examples of positive electrode binders are all organic binders and belong to organic components. Typically, the weight percentage of the positive electrode binder in the positive electrode active layer can be 0-10 wt%, more commonly 0-8 wt%, even more commonly 0.1 wt%-5 wt%, and even more commonly 1 wt%-5 wt%. When the positive electrode material is formulated into a positive electrode slurry using a wet process and then the positive electrode active layer is prepared, the positive electrode binder can be placed in the positive electrode slurry, which can assist in film formation and also promote the formation of a good electrical contact network between the active particles in the positive electrode active layer.

[0143] Non-limiting, the positive electrode active layer may include positive electrode active particles, positive electrode electrolyte particles, positive electrode conductive agent, and positive electrode binder. The types and amounts of each component can be found in the context of this application.

[0144] As a non-limiting example, the positive current collector has two surfaces that are opposite to each other in its own thickness direction, and the positive active layer is disposed on either or both of the two opposite surfaces of the positive current collector.

[0145] In some embodiments, the positive electrode current collector may be the composite current collector described above, or it may be a metal foil or composite current collector known in the art. For example, aluminum foil may be used as a metal foil known in the art. In the positive electrode current collector, a composite current collector known in the art may include a polymer material substrate and a metal conductive layer formed on at least one surface of the polymer material substrate. In the positive electrode current collector, the composite current collector can be obtained by forming a metal material on a polymer material substrate. Non-limiting examples of the metal material in the positive electrode current collector may include at least one of aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys. Non-limiting examples of the polymer material substrate in the positive electrode current collector may include one or more of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene (PE).

[0146] In some embodiments, the positive electrode sheet can be prepared by: dry mixing the components used to prepare the positive electrode sheet, such as positive electrode active particles, positive electrode electrolyte particles, positive electrode conductive agent, positive electrode binder, and any other components; then heating and pressurizing the mixed material to knead it into a clump; hot rolling pressing to form a self-supporting positive electrode sheet; and hot rolling bonding the self-supporting positive electrode sheet with a positive electrode current collector, wherein the self-supporting positive electrode sheet can be bonded to at least one side (single or double sides) of the positive electrode current collector to obtain the positive electrode sheet. Non-limitingly, a dual planetary mixer can be used for dry mixing. Non-limitingly, a kneading and pressing process can be performed using a Banbury mixer. Non-limitingly, the temperature for hot rolling pressing can be 75°C to 85°C, and further, such as 78°C, 80°C, 82°C, etc. The method of assembling solid-state batteries using positive electrode sheets is suitable for industrial mass production.

[0147] In some embodiments, the positive electrode sheet can be prepared by dispersing the components used to prepare the positive electrode sheet, such as positive electrode active particles, positive electrode electrolyte particles, positive electrode conductive agent, positive electrode binder, and any other components, in an organic solvent to form a positive electrode slurry. Further, the positive electrode slurry is coated onto at least one surface of the positive electrode current collector, and after drying, cold pressing, and other processes, the positive electrode sheet is obtained. Cold pressing can be performed using a cold rolling mill. Non-limitingly, the organic solvent in the positive electrode slurry can include one or more of p-xylene, trimethylbenzene, butyl butyrate, heptane, etc., and more specifically, p-xylene. The surface of the positive electrode current collector coated with the positive electrode slurry can be a single surface of the positive electrode current collector or both surfaces of the positive electrode current collector. The solid content of the positive electrode slurry can be 40wt% to 80wt%. The viscosity of the positive electrode slurry at room temperature can be adjusted to 5000 mPa·s to 25000 mPa·s.

[0148] The negative electrode layer can be provided by a pre-fabricated negative electrode sheet, which can be a negative electrode sheet that is available in the art for solid-state batteries.

[0149] The negative electrode sheet can be prepared by dry or wet methods. For example, it can be formed into a film by dry pressing. Alternatively, it can be formed into a film by wet coating.

[0150] In this application, unless otherwise specified, the negative electrode layer includes at least a negative electrode active layer.

[0151] In this application, unless otherwise stated, the negative electrode sheet includes at least a negative electrode active layer.

[0152] Unless otherwise stated, the negative electrode active layer in this application includes at least negative electrode active particles.

[0153] Without limitation, the negative electrode active layer may include a solid electrolyte. The solid electrolyte in the negative electrode active layer may be referred to as "negative electrode electrolyte particles".

[0154] In this application, unless otherwise specified, "negative electrode electrolyte particles" refers to solid electrolytes that can be used in the negative electrode layer. Negative electrode electrolyte particles can enhance the ion conductivity of the negative electrode layer, reduce interfacial impedance, and promote the charge transfer efficiency and full release of the capacity of the negative electrode active material with the external environment.

[0155] In this application, unless otherwise specified, "negative electrode active particles" refers to particles containing negative electrode active substances that have the ability to reversibly insert and extract active ions.

[0156] In some embodiments, the negative electrode sheet includes a negative electrode active layer, the negative electrode active layer includes negative electrode active particles, and the negative electrode active particles contain a negative electrode active substance.

[0157] Without limitation, the weight percentage of negative electrode active particles or negative electrode active materials in the negative electrode active layer can be ≥80wt%, and further ≥90wt%.

[0158] Non-limitingly, the weight percentage of the negative electrode electrolyte particles in the negative electrode active layer can be 0 to 30 wt%, preferably 0.1 wt% to 30 wt%, and further preferably 5 wt% to 20 wt%.

[0159] In some embodiments, the negative electrode active particles or negative electrode active material are lithium indium alloys (InLi alloys).

[0160] In some embodiments, the negative electrode layer or negative electrode sheet is an InLi alloy film.

[0161] In some embodiments, the negative electrode active material may also be a negative electrode active material known in the art for use in solid-state batteries. As a non-limiting example, the negative electrode active material may include one or more of the following materials: elemental silicon, elemental tin, silicon-carbon composites, silicon suboxide, graphite, and metallic lithium. However, this application is not limited to these materials or substances, and other conventional materials that can be used as battery negative electrode active materials may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0162] In some embodiments, the negative electrode sheet may include a negative current collector and a negative active layer disposed on at least one surface of the negative current collector, the negative active layer comprising a negative active material. As a non-limiting example, the negative current collector has two surfaces opposite to each other in its own thickness direction, and the negative active layer is disposed on either or both of the two opposite surfaces of the negative current collector.

[0163] In some embodiments, the negative electrode current collector may be a metal foil or a composite current collector. For example, copper foil may be used as the metal foil. In the negative electrode current collector, the composite current collector may include a polymer material substrate and a metal conductive layer formed on at least one surface of the polymer material substrate. In the negative electrode current collector, the composite current collector may be formed by forming a metal material on the polymer material substrate. Non-limiting examples of the metal material in the negative electrode current collector may include one or more of copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys. Non-limiting examples of the polymer material substrate in the negative electrode current collector may include one or more of polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polystyrene (PS), and polyethylene (PE).

[0164] In some embodiments, the negative electrode active layer optionally includes a conductive agent (which may be referred to as a negative electrode conductive agent). Non-limitingly, the negative electrode conductive agent may include one or more of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers. Non-limitingly, the weight percentage of the negative electrode conductive agent in the negative electrode active layer may be 0-15 wt%, more preferably 0-10 wt%, and even more preferably 0-5 wt%.

[0165] In some embodiments, the negative electrode active layer optionally includes an adhesive (denoted as negative electrode adhesive). As a non-limiting example, the negative electrode adhesive may include one or more of styrene-butadiene rubber (SBR), polyacrylic acid (PAA), sodium polyacrylate (PAAS), polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium alginate (SA), polymethacrylic acid (PMAA), and carboxymethyl chitosan (CMCS). Non-limitingly, the weight percentage of the negative electrode adhesive in the negative electrode active layer may be 0 to 10 wt%, more further 0 to 5 wt%, even more further 1 wt% to 5 wt%, and even more preferably 1 wt% to 3 wt%.

[0166] In some embodiments, the negative electrode active layer may optionally include other additives, such as thickeners (e.g., sodium carboxymethyl cellulose (CMC-Na)). The weight percentage of the other additives in the negative electrode active layer may be 0-15 wt%, more preferably 0-10 wt%, even more preferably 0-5 wt%, even more preferably 0-3 wt%, and even more preferably 0-2 wt%.

[0167] In some embodiments, the negative electrode sheet can be prepared by dispersing the components used to prepare the negative electrode sheet, such as negative electrode active particles, negative electrode conductive agent, negative electrode binder, and any other components, in a solvent (a non-limiting example of a solvent is p-xylene) to form a negative electrode slurry. Further, the negative electrode slurry is coated onto at least one surface of the negative electrode current collector, and after drying, cold pressing, and other processes, the negative electrode sheet is obtained. Cold pressing can be performed using a cold rolling mill. The surface of the negative electrode current collector coated with the negative electrode slurry can be a single surface of the negative electrode current collector or both surfaces of the negative electrode current collector. The solid content of the negative electrode slurry can be 30wt% to 70wt%, optionally 40wt% to 60wt%. The viscosity of the negative electrode slurry at room temperature can be adjusted to 2000 mPa·s to 10000 mPa·s, optionally 3000 mPa·s to 10000 mPa·s.

[0168] Typically, a solid-state battery consists of a positive electrode layer, a solid electrolyte layer, and a negative electrode layer. The solid electrolyte layer is located between the positive and negative electrode layers. The solid electrolyte layer serves to conduct ions between the positive and negative electrode layers and also isolates them, thus preventing short circuits between the positive and negative electrodes.

[0169] A solid electrolyte layer can be introduced by forming electrode layers on both sides of the solid electrolyte membrane, or it can be introduced on the electrode layer.

[0170] It is understood that the solid electrolyte in the solid electrolyte layer can be any solid electrolyte known in the art that can be used in solid-state batteries.

[0171] The types of solid electrolytes present in different film layers of a solid-state battery can be the same or different. For example, the solid electrolytes in the positive electrode layer and the solid electrolyte layer can be the same or different.

[0172] As a non-limiting example, in different film layers of a solid-state battery, the solid electrolyte may include one or more of the following: sulfide solid electrolyte, halide solid electrolyte, oxide solid electrolyte, polymer solid electrolyte, etc.

[0173] As another non-limiting example, in different film layers of a solid-state battery, the solid electrolyte can be, but is not limited to, one or more of oxide-based solid electrolytes, sulfide-based solid electrolytes, and halide-based solid electrolytes. In some embodiments, the solid electrolyte can independently include, but is not limited to, one or more of Argyrodite-type sulfide electrolytes and halide electrolytes. Non-limiting examples of oxide-based solid electrolytes may include LISICON-type oxide electrolytes (such as γ-Li3PO4), NASICON-type oxide electrolytes (such as Li... 1+x Alx Ge 2-x (PO4)3,Li 1+x Al x Ti 2-x (PO4)3, etc., 0≤x≤1), Garnet type (such as Li7La3Zr2O12, etc.), perovskite type oxide electrolytes (such as Li 3x La 2 / 3-x One or more of the following: TiO3, etc. (0≤x≤0.5). Non-limiting examples of sulfide solid electrolytes may include Li. 10 GeP2S 12 Li₂S-P₂S₅, Argyrodite type (such as Li₆PS₅Cl, Li 5.5 PS 5.5 Cl 1.5 One or more of the following (etc.). Non-limiting examples of halide solid electrolytes may include one or more of the following: Li3InCl6, Li3YCl6, Li3ScCl6, Li3ErCl6, Li2ZrCl6, etc.

[0174] Solid electrolyte membranes or solid electrolyte layers can be prepared using dry methods. In some embodiments, the solid electrolyte layer can be formed by pressing solid electrolyte materials into a solid electrolyte membrane. In other embodiments, the solid electrolyte layer is formed by pressing the constituent raw materials of the solid electrolyte layer onto an electrode layer. In still other embodiments, the solid electrolyte membrane can also be prepared using methods such as fibrosis combined with calendering, melt extrusion, or spraying.

[0175] In this application, the sheet-like solid electrolyte membrane may also be referred to as a solid electrolyte membrane sheet.

[0176] Solid electrolyte layers can also be prepared using a wet process. The electrolyte slurry used includes at least a solid electrolyte and an organic solvent, and usually also includes one or more of a binder and a dispersant.

[0177] In some embodiments, the thickness of the solid electrolyte layer can be 0.1 μm to 1000 μm, and can be selected as 10 μm to 100 μm, 100 μm to 800 μm, 500 μm to 800 μm, etc.

[0178] In a non-limiting manner, the positive electrode layer, the solid electrolyte layer, and the negative electrode layer can be assembled in a stacked manner, with the solid electrolyte layer placed between the positive electrode layer and the negative electrode layer.

[0179] Non-limitingly, a solid-state battery cell can be prepared by stacking a positive electrode, a solid electrolyte membrane, and a negative electrode in sequence, placing the solid electrolyte membrane between the positive and negative electrodes, and then rolling them together.

[0180] Non-limitingly, a solid-state battery cell can be prepared by sequentially stacking a positive electrode membrane, a solid electrolyte membrane, and a negative electrode membrane, with the solid electrolyte membrane placed between the positive and negative electrode membranes, and then rolling. The rolling process can be either cold rolling or hot rolling. A non-limiting example of a hot rolling temperature is 180°C.

[0181] In a second aspect, this application also provides a composite current collector, which is the composite current collector in the solid-state battery provided in the first aspect of this application. It includes a metal conductive layer, a conductive aerogel layer, and a thermistor material layer. The thermistor material layer includes a thermistor material with a positive temperature coefficient. The thermistor material layer is located between the conductive aerogel layer and the metal conductive layer, or the conductive aerogel layer is located between the metal conductive layer and the thermistor material layer.

[0182] In some embodiments, the composite current collector has the same technical features and effects as the composite current collector in the solid-state battery, which will not be repeated here.

[0183] A third aspect of this application also provides a method for preparing a composite current collector, comprising the following steps:

[0184] A stacked structure comprising a metal conductive layer, a conductive aerogel layer, and a thermistor material layer is formed; wherein, the thermistor material layer comprises a thermistor material with a positive temperature coefficient; the thermistor material layer is located between the conductive aerogel layer and the metal conductive layer, or the conductive aerogel layer is located between the metal conductive layer and the thermistor material layer.

[0185] In some embodiments, the metal conductive layer can be provided directly by metal foil, or it can be formed on the corresponding substrate by a coating method, including but not limited to one or more of vacuum evaporation, magnetron sputtering, plasma plating, molecular beam epitaxy, laser pulse plating, and electroplating.

[0186] In some embodiments, the conductive aerogel layer can be provided by commercially available conductive aerogel films or prepared on a suitable substrate by a solution method.

[0187] As an example, the steps for preparing a conductive aerogel layer using a solution method may include the following: dispersing a conductive material (such as carbon nanotubes, graphene, etc.) in a solvent to form a conductive material dispersion; dissolving a gel matrix in the solvent to form a gel matrix solution; mixing the conductive material dispersion and the gel matrix solution, adding a crosslinking agent to obtain a precursor mixture; placing the precursor mixture in a mold and allowing it to solidify, which may be done by heat treatment; and after the formed conductive aerogel film is completely dry, demolding to obtain the conductive aerogel film.

[0188] In some embodiments, the thermistor material layer can be provided by commercially available thermistor material film or prepared by coating.

[0189] In some embodiments, the weight percentage of the thermistor material in the thermistor material layer can be 70wt% to 100wt%, further ≥80wt%, even further ≥90wt%, and can also be 70wt% to 99wt%, optionally 80wt% to 95wt%.

[0190] In some embodiments, the thermistor material layer may optionally include an adhesive in addition to the thermistor material described above. The adhesive may be a conductive adhesive, including but not limited to one or more of polyaniline (PANI) and polypyrrole (PPy).

[0191] Furthermore, the weight percentage of the binder in the thermistor material layer can be 0~10wt%, further can be 0~8wt%, even further can be 0.1wt%~5wt%, and even further can be 1wt%~5wt%.

[0192] Furthermore, in addition to the aforementioned thermistor material, the thermistor material layer may optionally include a conductive agent. The conductive agent may be a carbon conductive agent. Non-limitingly, the carbon conductive agent may include one or more of superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers.

[0193] Furthermore, the weight percentage of the conductive agent in the thermistor material layer can be 0~10wt%, further can be 0~8wt%, even further can be 0.1wt%~5wt%, and even further can be 1wt%~5wt%.

[0194] As an example, the thermistor material layer can be prepared by mixing the above-mentioned thermistor material with an optional binder, an optional conductive agent, and a solvent to form a slurry, coating the slurry onto the corresponding substrate, and drying it.

[0195] Understandably, solid-state batteries stack layers by applying pressure, so composite current collectors can also be stacked in the required order by layering a metal conductive layer, a conductive aerogel layer, and a thermistor material layer, while maintaining good contact between the layers during the pressurization process.

[0196] The third aspect of this application also provides an electrical device, comprising at least one of the solid-state battery of the first aspect of this application, the composite current collector of the second aspect of this application, and the composite current collector prepared by the preparation method of the third aspect of this application.

[0197] The solid-state battery and power device of this application will be described below with appropriate reference to the accompanying drawings. This application does not impose any particular limitation on the shape of the solid-state battery cell; it can be cylindrical, square, or any other arbitrary shape. For example, Figure 5 This is an example of a square-structured solid-state battery cell 5.

[0198] In some embodiments, the solid-state battery cell 5 includes a solid-state cell 52.

[0199] In some implementations, the solid-state cell is an all-solid-state cell.

[0200] In some embodiments, the solid-state cell 52 (which may be an all-solid-state cell) includes a positive electrode layer, a solid electrolyte layer, and a negative electrode layer stacked sequentially.

[0201] In some embodiments, the solid-state battery may include an outer packaging. This outer packaging can be used to encapsulate the aforementioned solid-state battery cell.

[0202] In some embodiments, the outer packaging of a solid-state battery can be a rigid shell, such as a hard plastic shell, an aluminum shell, or a steel shell. The outer packaging of a solid-state battery can also be a soft pack, such as a pouch-type soft pack. The material of the soft pack can be plastic; further, non-limiting examples of plastics may include one or more of polypropylene, polybutylene terephthalate, and polybutylene succinate.

[0203] In some of these implementations, reference is made to... Figure 6 The outer packaging may include a housing 51 and a cover 53. The housing 51 may include a base plate and side plates connected to the base plate, the base plate and side plates forming a receiving cavity. The housing 51 has an opening communicating with the receiving cavity, and the cover 53 can be placed over the opening to close the receiving cavity. A solid-state battery cell 52 is encapsulated within the receiving cavity. The number of solid-state battery cells 52 contained in a single solid-state battery cell 5 may be one or more, which can be selected by those skilled in the art according to actual needs.

[0204] Solid-state batteries can be battery device 4 or battery pack 1.

[0205] The battery device includes at least one solid-state battery cell. The number of solid-state battery cells in the battery device can be one or more, and those skilled in the art can select an appropriate number according to the application and capacity of the battery device.

[0206] Figure 7 This is battery device 4, used as an example. (See reference...) Figure 7 In the battery device 4, multiple solid-state battery cells 5 can be arranged sequentially along the length of the battery device 4. Of course, they can also be arranged in any other manner. Furthermore, the multiple solid-state battery cells 5 can be fixed in place using fasteners.

[0207] Optionally, the battery device 4 may also include a housing with a receiving space in which a plurality of solid-state battery cells 5 are housed.

[0208] In some embodiments, the battery devices described above can also be assembled into a battery pack, and the number of battery devices contained in the battery pack can be one or more. Those skilled in the art can select an appropriate number according to the application and capacity of the battery pack.

[0209] Figure 8 and Figure 9 This is battery pack 1 as an example. (See reference...) Figure 8 and Figure 9 The battery pack 1 may include a battery box and multiple battery devices 4 disposed within the battery box. The battery box includes an upper body 2 and a lower body 3, with the upper body 2 covering the lower body 3 to form a closed space for accommodating the battery devices 4. The multiple battery devices 4 can be arranged in any manner within the battery box.

[0210] In some embodiments, multiple battery cells 5 can also be arranged in any way in the battery box to directly obtain a solid-state battery.

[0211] This application also provides an electrical device comprising at least one of the solid-state battery described in the first aspect of this application, the negative electrode or solid-state battery described in the second aspect of this application, and the negative electrode or solid-state battery prepared by the above-described preparation method of this application.

[0212] In some embodiments, the electrical device includes at least one of the solid-state batteries of any of the embodiments provided in this application.

[0213] In a non-limiting sense, solid-state batteries can be used as a power source for electrical devices or as an energy storage unit for electrical devices. Electrical devices can include, but are not limited to, mobile devices, electric vehicles, electric trains, ships and satellites, energy storage systems, etc. Mobile devices can be, for example, mobile phones, laptops, etc.; electric vehicles can be, for example, pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, electric motorcycles, power tools, etc., but are not limited to these. This electrical device can also be applied to military equipment, aerospace, and other fields, and can also be applied to energy storage power systems such as hydroelectric, thermal, wind, and solar power plants.

[0214] As an electrical device, solid-state batteries can be selected based on its usage requirements.

[0215] Figure 10Here is an example of an electrical device 6. This electrical device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc. To meet the high power and high energy density requirements of this electrical device for solid-state batteries, a battery device or battery pack can be used as the power source.

[0216] Another example device could be a mobile phone, tablet, or laptop. These devices typically require a thin and light design and can use solid-state battery cells as their power source.

[0217] To make the technical problems, technical solutions, and beneficial effects solved by this application clearer, the application will be further described in detail below with reference to embodiments and accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this application or its applications. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0218] Where specific techniques or conditions are not specified in the examples, they shall be performed in accordance with the techniques or conditions described in the literature in this field or in accordance with the product instructions. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0219] Example 1

[0220] 1. Preparation of composite current collector 1. The structure of the composite current collector is as follows: Figure 2 The composite current collector 7 shown includes a stacked metal conductive layer 71, a thermistor material layer 73, a conductive aerogel layer 72, and the thermistor material layer 73. The conductive aerogel layer 72 extends out as an electrode tab 74, and the electrode connection terminal is connected to the electrode tab 74.

[0221] The preparation process is as follows:

[0222] A 5μm thick thermistor material layer is formed by coating both surfaces of a conductive aerogel film; wherein the conductive aerogel film is made of carbon aerogel and the thermistor material layer includes Cu2O-doped barium titanate.

[0223] A 5μm thick metal conductive layer (made of aluminum) is deposited on the surface of the thermistor material layers on both sides.

[0224] The preparation of composite current collector 2 is basically the same as that of composite current collector 1, except that the metal conductive layer (made of copper) is different.

[0225] 2. Preparation of the positive electrode sheet. The positive electrode active material (NCM811), Li6PS5Cl (LPSCl) sulfide electrolyte (Dv50 of 700 nm), conductive agent vapor-grown carbon fiber (VGCF), and binder PTFE were weighed in a mass ratio of 70:25.5:2.5:2 and mixed evenly. The mixture was heated on a heating stage at 80°C and formed into a self-supporting positive electrode sheet with a thickness of 120 μm by rolling on the heating stage. The self-supporting positive electrode sheet was then combined with the above-mentioned composite current collector 1 by hot roller and cut to a suitable size to obtain the positive electrode sheet.

[0226] 3. Preparation of the negative electrode sheet. Silicon, the negative electrode active material, is mixed with styrene-butadiene rubber (SBR) as a binder and carbon black as a conductive agent at a mass ratio of 95:3.5:1.5. Tris(II)-methylbenzene is added as a solvent, and the mixture is stirred until uniformly dispersed to obtain a slurry. This slurry is then uniformly coated onto the composite current collector 2 described above and baked in an oven to remove the solvent, forming a 70 μm thick negative electrode active layer. This yields the negative electrode sheet.

[0227] 4. Solid electrolyte layer.

[0228] Weigh 100 mg of sulfide electrolyte Li6PS5Cl (LPSCl) and binder PTFE in a mass ratio of 98:2, heat on a heating table at 80°C, and form a solid electrolyte layer with a thickness of 150 μm by rolling on the heating table.

[0229] 5. Battery assembly.

[0230] The positive electrode, solid electrolyte layer, and negative electrode prepared above are assembled in an alternating manner (stacked battery), and then hot-pressed (pressurized at 500MPa for 5min), and sealed with aluminum-plastic film under negative pressure to obtain a soft-pack all-solid-state battery cell.

[0231] Example 2

[0232] The process is essentially the same as in Example 1, except that the composite current collectors used for the positive and negative electrodes have different structures. The only difference between the composite current collectors used for the positive and negative electrodes and those in Example 1 is that the positions of the metal conductive layer 71 and the thermistor material layer 73 in the composite current collector 1 are interchanged, and their structures are as follows: Figure 3 The composite current collector 7 shown includes a stacked thermistor material layer 73, a metal conductive layer 71, a conductive aerogel layer 72, and a thermistor material layer 73. The conductive aerogel layer 72 extends out to serve as an electrode tab 74. Accordingly, the preparation steps of the composite current collector are simply reversed in order. Correspondingly, the positions of the metal conductive layer 71 and the thermistor material layer 73 in the composite current collector 2 are also interchanged.

[0233] Example 3

[0234] The process is essentially the same as in Example 1, except that the composite current collectors used in the positive and negative electrodes have different structures. The structures of the composite current collectors used in the positive and negative electrodes are as follows: Figure 4 The composite current collector 7 shown includes a thermistor material layer 73, a conductive aerogel layer 72, a metal conductive layer 71, a conductive aerogel layer 72, and a thermistor material layer 73 stacked together. The metal conductive layer 71 of the composite current collector 7 is led out as an electrode tab 74, and an electrode connection terminal is connected to the electrode tab 74.

[0235] The composite current collector in Example 3 was prepared as follows:

[0236] Conductive aerogel layers with a thickness of 5 μm are formed on both surfaces of a metal foil (the metal foil in the composite current collector of the positive electrode is made of aluminum, and the metal foil in the composite current collector of the negative electrode is made of copper) by a solution method; wherein, the conductive aerogel film is made of carbon aerogel.

[0237] A thermistor material layer with a thickness of 5 μm is coated on the surface of both conductive aerogel layers. The thermistor material layer consists of Cu2O-doped barium titanate.

[0238] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0239] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims, and the specification and drawings can be used to interpret the scope of the claims.

Claims

1. A solid-state battery, characterized in that, It includes at least two electrode layers, wherein the current collector of at least one electrode layer is a composite current collector, the composite current collector includes a metal conductive layer, a conductive aerogel layer and a thermistor material layer, the thermistor material layer includes a thermistor material with a positive temperature coefficient, and the conductive aerogel layer is disposed on the metal conductive layer; The thermistor material layer is located between the conductive aerogel layer and the metal conductive layer, or the thermistor material layer is located on the surface of the metal conductive layer away from the conductive aerogel layer, or the thermistor material layer is located on the surface of the conductive aerogel layer away from the metal conductive layer.

2. The solid-state battery as described in claim 1, characterized in that, It meets one or more of the following characteristics: (1) The porosity of the conductive aerogel layer is 80%~99.8%, and can be selected as 85%~99.8%; (2) The density of the conductive aerogel layer is 0.003 g / cm³. 3 ~0.1g / cm 3 The option is 0.01 g / cm³. 3 ~0.05g / cm 3 ; (3) The conductivity of the conductive aerogel layer is ≥30S / cm, and can be selected as 30S / cm~80S / cm.

3. The solid-state battery according to any one of claims 1 to 2, characterized in that, It meets one or more of the following characteristics: (1) The components of the conductive aerogel layer include one or more of carbon nanotubes, carbon aerogel, MXene, graphene and conductive polymers; (2) The thickness of the conductive aerogel layer is 1μm~10μm, and can be selected as 2μm~10μm.

4. The solid-state battery according to any one of claims 1 to 3, characterized in that, It meets one or more of the following characteristics: (1) The conductivity of the thermistor material at 25℃ is 50S / cm~500S / cm; (2) The Curie temperature of the thermistor material is 80°C~100°C.

5. The solid-state battery according to any one of claims 1 to 4, characterized in that, It meets one or more of the following characteristics: (1) The thermistor material includes a matrix material doped with a metal element, wherein the matrix material includes a ceramic material; optionally, the metal element includes one or more of Y, La, Nb, Ta, Bi, Sb, Ru, Mn, Fe, Cu and Cr; optionally, the ceramic material includes one or more of barium titanate, strontium titanate, lead titanate, strontium carbonate, titanium dioxide, iron oxide and vanadium oxide; (2) The thickness of the thermistor material layer is 0.1μm~10μm, and can be selected as 0.1μm~5μm.

6. The solid-state battery according to any one of claims 1 to 5, characterized in that, It meets one or more of the following characteristics: (1) The metal conductive layer includes a metal conductive layer of one of iron, copper, aluminum, nickel, titanium and silver or an alloy layer containing at least one of copper, aluminum, nickel, titanium and silver. (2) The thickness of the metal conductive layer is 0.1μm~10μm, and can be selected as 0.1μm~5μm.

7. The solid-state battery according to any one of claims 1 to 6, characterized in that, The electrode layer further includes an electrode active layer disposed on at least one side of the composite current collector.

8. The solid-state battery as described in claim 7, characterized in that, The thermistor material layer is located between the conductive aerogel layer and the metal conductive layer, and the electrode active layer is at least located on the side of the metal conductive layer away from the thermistor material layer.

9. The solid-state battery according to any one of claims 1 to 8, characterized in that, In the composite current collector, the conductive aerogel layer has the thermistor material layer and the metal conductive layer sequentially stacked on both sides of its thickness direction; Optionally, an electrode active layer is provided on the side of the metal conductive layer away from the thermistor material layer on both sides of the conductive aerogel layer.

10. The solid-state battery as claimed in claim 7, characterized in that, The thermistor material layer is located on the surface of the metal conductive layer away from the conductive aerogel layer, and the electrode active layer is at least located on the side of the thermistor material layer away from the metal conductive layer.

11. The solid-state battery according to any one of claims 1 to 7 and 10, characterized in that, In the composite current collector, the conductive aerogel layer has the metal conductive layer and the thermistor material layer stacked sequentially on both sides of its thickness direction; Optionally, an electrode active layer is provided on the side of the thermistor material layer away from the metal conductive layer on both sides of the conductive aerogel layer.

12. The solid-state battery according to any one of claims 1 to 11, characterized in that, The solid-state battery further includes an electrode connection terminal, which is connected to the conductive aerogel layer of the composite current collector.

13. The solid-state battery as described in claim 12, characterized in that, The conductive aerogel layer of the composite current collector is led out as an electrode tab, and the electrode connection terminal is connected to the electrode tab.

14. The solid-state battery as described in claim 7, characterized in that, The thermistor material layer is located on the surface of the conductive aerogel layer away from the metal conductive layer, and the electrode active layer is at least located on the side of the thermistor material layer away from the conductive aerogel layer.

15. The solid-state battery according to any one of claims 1 to 7 and 14, characterized in that, In the composite current collector, the conductive metal layer has the conductive aerogel layer and the thermistor material layer stacked sequentially on both sides of its thickness direction. Optionally, an electrode active layer is provided on the side of the thermistor material layer away from the conductive aerogel layer on both sides of the metal conductive layer.

16. The solid-state battery according to any one of claims 1 to 7, 14 to 15, characterized in that, The solid-state battery further includes an electrode connection terminal, which is connected to the metal conductive layer of the composite current collector.

17. The solid-state battery as claimed in claim 16, characterized in that, The metal conductive layer of the composite current collector is led out as an electrode tab, and the electrode connection terminal is connected to the electrode tab.

18. The solid-state battery according to any one of claims 1 to 17, characterized in that, The solid-state battery is a solid-state battery.

19. The solid-state battery according to any one of claims 1 to 18, characterized in that, The solid-state battery is an all-solid-state battery.

20. A composite current collector, characterized in that, The composite current collector includes a metal conductive layer, a conductive aerogel layer, and a thermistor material layer. The thermistor material layer includes a thermistor material with a positive temperature coefficient. The thermistor material layer is located between the conductive aerogel layer and the metal conductive layer, or the conductive aerogel layer is located between the metal conductive layer and the thermistor material layer.

21. The composite current collector as described in claim 20, characterized in that, The composite current collector is the composite current collector in the solid-state battery as described in any one of claims 2 to 19.

22. A method for preparing a composite current collector, characterized in that, Includes the following steps: A stacked structure is formed comprising a metal conductive layer, a conductive aerogel layer, and a thermistor material layer; wherein the thermistor material layer comprises a thermistor material with a positive temperature coefficient; the thermistor material layer is located between the conductive aerogel layer and the metal conductive layer, or the conductive aerogel layer is located between the metal conductive layer and the thermistor material layer.

23. An electrical appliance, characterized in that, It includes at least one of the solid-state battery according to any one of claims 1 to 19, the composite current collector according to claim 20 or 21, and the composite current collector prepared by the preparation method according to claim 22.

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