Method for detecting density of solid-state battery, solid-state battery and electric device
By densifying the solid-state battery stack and using the dimensional shrinkage rate to determine the density, the problem of batch testing being difficult to achieve with destructive operations in existing technologies is solved, thus realizing non-destructive testing and high-efficiency testing.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CONTEMPORARY AMPEREX TECHNOLOGY CO LTD
- Filing Date
- 2024-12-10
- Publication Date
- 2026-06-12
AI Technical Summary
Existing technologies require destructive operations to measure the density of solid-state batteries, making it difficult to achieve batch testing.
By densifying the stacked material to reduce its volume, the density can be determined using the dimensional shrinkage rate, thus avoiding destructive operations and achieving non-destructive testing.
This technology enables non-destructive testing of the density of solid-state batteries, making it suitable for batch testing and improving testing efficiency.
Smart Images
Figure CN122193002A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of battery technology, and in particular to a method for detecting the density of a solid-state battery, a solid-state battery, and an electrical device thereof. Background Technology
[0002] With the popularization and promotion of new energy vehicles, their charging and discharging performance and range have increasingly attracted people's attention and importance. As the power energy source for new energy vehicles, power batteries are widely used.
[0003] Solid-state batteries, as one of the future development trends of power batteries, have advantages such as high energy density and good safety. The density of solid-state batteries affects their charge-discharge performance. Currently, determining the density of a solid-state battery requires destructive operations such as stamping, followed by measurement of the stamped density and porosity to determine the battery's density. Because measuring the density of solid-state batteries requires destructive operations like stamping, it is only suitable for small-sample sampling and is difficult to apply to batch testing of solid-state batteries. Summary of the Invention
[0004] Therefore, it is necessary to provide a density testing method for solid-state batteries, as well as solid-state batteries and electrical equipment, to address the problem that the density testing of solid-state batteries requires destructive operations such as wafer punching, which makes it difficult to apply to batch testing.
[0005] A method for detecting the density of a solid-state battery includes the following steps: stacking a negative electrode, a solid electrolyte, and a positive electrode to form a stack; obtaining the initial dimensions of the stack; performing a densification process on the stack to shrink its volume; obtaining the shrunk dimensions of the stack; obtaining the dimensional shrinkage rate of the stack based on the shrunk dimensions and the initial dimensions, and determining the density of the solid-state battery based on the dimensional shrinkage rate. This method further densifies the solid-state battery by performing a densification process on the stack to shrink its volume, facilitating density characterization and subsequent testing. By obtaining the dimensional shrinkage rate of the stack based on the shrunk dimensions and the initial dimensions, and determining the density of the solid-state battery based on the dimensional shrinkage rate, this method avoids the need for destructive operations such as stamping when measuring the density of solid-state batteries, achieving non-destructive testing of the density of solid-state batteries and enabling its application in batch testing.
[0006] In some embodiments, the step of obtaining the initial dimensions of the stack includes the following step: pre-compressing the stack along the stacking direction to ensure that the negative electrode, solid electrolyte, and positive electrode are in close contact along the stacking direction. This pre-compressing of the stack along the stacking direction enables further densification of the solid-state battery, facilitating density characterization and subsequent testing.
[0007] In some embodiments, during pre-compression, the stack is pre-compressed along the stacking direction at a pressure of 0.0294 MPa to 0.245 MPa for 5 to 20 minutes, and at an ambient temperature of 25°C to 150°C. This allows the negative electrode, solid electrolyte, and positive electrode to be tightly bonded along the stacking direction, achieving further densification of the solid-state battery.
[0008] In some embodiments, densification of the stack is achieved by performing isostatic pressing or flat pressing on the stack. This allows for the selection of an appropriate densification method based on the specific circumstances.
[0009] In some embodiments, the step of performing isostatic pressing on the stack includes: placing the stack in an isostatic container; filling the isostatic container with an isostatic medium; applying pressure to the outer periphery of the isostatic container and transmitting the pressure to the stack through the isostatic medium, thereby causing the volume of the stack to shrink. In this way, performing isostatic pressing on the stack causes a certain volume deformation, achieving further densification of the solid-state battery.
[0010] In some embodiments, during the isostatic pressing process on the stack, the isostatic pressure is 100 MPa to 3000 MPa, the isostatic pressing time is 5 min to 60 min, and the isostatic pressing ambient temperature is 25°C to 2000°C. This allows the negative electrode, solid electrolyte, and positive electrode to be tightly bonded along the stacking direction, achieving further densification of the solid-state battery.
[0011] In some embodiments, the isostatic pressure is 1000 MPa to 3000 MPa, and the isostatic ambient temperature is 25°C to 50°C. Thus, under high pressure and low temperature conditions, the stack is pressurized, and the isostatic medium transmits the pressure to the stack, causing the volume of the stack to shrink.
[0012] In some embodiments, the isostatic pressure is 300 MPa to 1000 MPa, and the isostatic ambient temperature is 50°C to 200°C. Thus, under moderate pressure and temperature, the stack is pressurized, and the isostatic medium transmits the pressure to the stack, causing the volume of the stack to shrink.
[0013] In some embodiments, the isostatic pressure is between 100 MPa and 300 MPa, and the isostatic ambient temperature is between 200°C and 2000°C. Thus, under conditions of low pressure and high temperature, the stack is pressurized, and the isostatic medium transmits the pressure to the stack, causing the volume of the stack to shrink.
[0014] In some embodiments, the isostatic medium is one of esters, water, or an inert gas. This allows for flexible selection of the isostatic medium material based on specific circumstances.
[0015] In some embodiments, the step of performing a flattening operation on the stack includes: placing the stack between two pressure blocks; applying pressure to the two pressure blocks and transmitting the pressure to the stack through the two pressure blocks to cause the volume of the stack to shrink. Thus, performing a flattening operation on the stack causes a certain volume deformation of the stack, achieving further densification of the solid-state battery.
[0016] In some embodiments, during the step of performing a flattening operation on the stack, the flattening pressure is 9.84 MPa to 73.54 MPa, the flattening time is 1 min to 20 min, and the flattening ambient temperature is 50°C to 300°C. This causes the stack to shrink in a predetermined direction, resulting in a certain volumetric deformation of the stack.
[0017] In some embodiments, at least one pressing block is provided with a heating element. Thus, when energized, the pressing block gradually heats up and transfers heat to the stack, so that a preset pressing ambient temperature can be reached during the pressing operation.
[0018] A solid-state battery is prepared using the aforementioned density detection method. The solid-state battery obtains the dimensional shrinkage rate of the stacked structure based on its shrinkage size and initial size, and determines the density of the solid-state battery based on this dimensional shrinkage rate. This method improves upon the need for destructive operations such as lamination to measure the density of solid-state batteries, achieving non-destructive testing of the density of solid-state batteries and enabling its application in batch testing.
[0019] An electrical device includes the aforementioned solid-state battery. This device enables non-destructive testing of the density of solid-state batteries, can be applied to batch testing of solid-state batteries, and improves the battery life stability of the device. Attached Figure Description
[0020] Figure 1 This is a schematic diagram of the electrical equipment in some embodiments of this application.
[0021] Figure 2 This is a schematic diagram of a stack of solid-state batteries according to some embodiments of this application.
[0022] Figure 3 This is a flowchart illustrating the density detection method for solid-state batteries in some embodiments of this application.
[0023] Figure 4 This is a schematic diagram of step S201 in the density detection method of solid-state batteries in some embodiments of this application.
[0024] Figure 5 This is a schematic diagram of the isostatic pressing operation in some embodiments of this application.
[0025] Figure 6 This is a schematic diagram of an isostatic pressure vessel in some embodiments of this application.
[0026] Figure 7 This is a flowchart illustrating the flattening operation in some embodiments of this application.
[0027] Figure 8 This is a schematic diagram of the pressure block in some embodiments of this application.
[0028] Figure label:
[0029] 10. Vehicle; 11. Controller; 12. Motor; 20. Solid-state battery; 21. Stack; 30. Isostatic container; 31. Isostatic medium; 40. Press block. Detailed Implementation
[0030] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.
[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.
[0032] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.
[0033] 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 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.
[0034] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.
[0035] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).
[0036] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.
[0037] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.
[0038] With the popularization and promotion of new energy vehicles, their charging and discharging performance and range have increasingly attracted people's attention and importance. As the power energy source for new energy vehicles, power batteries are widely used.
[0039] Solid-state batteries, as one of the future development trends of power batteries, have advantages such as high energy density and good safety. The density of solid-state batteries affects their charge-discharge performance. Currently, determining the density of a solid-state battery requires destructive operations such as stamping, followed by measurement of the stamped density and porosity to determine the battery's density. Because measuring the density of solid-state batteries requires destructive operations like stamping, it is only suitable for small-sample sampling and is difficult to apply to batch testing of solid-state batteries.
[0040] Based on the above considerations, and through in-depth research, this application designs a density detection method for solid-state batteries, a solid-state battery, and an electrical device. In the density detection method for solid-state batteries, the stacked body is densified to shrink its volume, thereby achieving further densification of the solid-state battery and facilitating density characterization and subsequent testing. The dimensional shrinkage rate of the stacked body is obtained based on its shrinkage size and initial size, and the density of the solid-state battery is determined by the dimensional shrinkage rate. This improves upon the need for destructive operations such as stamping to measure the density of solid-state batteries, achieving non-destructive testing of the density of solid-state batteries and enabling its application in batch testing of solid-state batteries.
[0041] The solid-state battery of this application embodiment typically includes: a negative electrode, a solid electrolyte, and a positive electrode. The negative electrode includes a negative electrode current collector and a negative electrode active material layer, the negative electrode active material layer being coated on the surface of the negative electrode current collector.
[0042] The negative electrode current collector can be pure lithium, a lithium alloy, or a lithium metal composite oxide. Lithium alloys are alloy materials, including lithium metal and other metals (such as any one or more of aluminum, magnesium, potassium, sodium, and calcium); lithium metal composite oxides are oxides composed of lithium and other metals (such as silicon, tin, zinc, magnesium, cadmium, cerium, and nickel). The negative electrode current collector may also have a protective layer, which can include any material as long as it has lithium-ion conductivity, does not interfere with battery operation, and does not react with lithium. For example, a ceramic protective layer or a lithium-ion polyacrylic acid protective layer can be provided. Any protective layer can be used for the negative electrode current collector in this application embodiment, as long as the protective layer improves the safety of the negative electrode current collector. The negative electrode active material includes at least one of lithium titanate, silicon anode, silicon-carbon anode, lithium metal anode material, tin-based anode material, and tin oxide anode material.
[0043] In this embodiment of the application, the solid electrolyte may include at least one of sulfide solid electrolyte, oxide solid electrolyte and organic solid electrolyte.
[0044] Sulfide-based solid electrolytes possess high lithium-ion conductivity, readily forming a contact interface between the electrode and the electrolyte, and exhibit high mechanical strength and flexibility. In this application, there are no particular limitations on the type of sulfide-based solid electrolyte, and all known sulfide materials used in the battery field are acceptable.
[0045] Oxide-based solid electrolytes exhibit high safety in air and possess lithium-ion conductivity that is lower than, but relatively higher than, that of sulfide-based solid electrolytes. Furthermore, oxide-based solid electrolytes exhibit high electrochemical safety and mechanical strength, and also have high oxidation voltage. However, solid electrolytes have high grain boundary resistance, making it difficult to form a contact interface between the electrode and the electrolyte, requiring high-temperature heat treatment processes of 1000°C or higher, and these processes are difficult to scale up. In the embodiments of this application, the oxide-based solid electrolyte can be any known oxide material used in the field of lithium batteries.
[0046] Organic solid electrolytes (OSEs) are a type of solid electrolyte. OSEs can readily form electrode interfaces and minimize dendrite growth, thus ensuring stable reactions between OSEs and lithium metal. The disadvantages of OSEs are their relatively low lithium-ion conductivity and the fact that they typically require high-temperature operation. In this embodiment, the OSE comprises polyethylene oxide.
[0047] The positive electrode in this application typically includes a positive current collector and a positive active material layer, with the positive active material layer coated on the surface of the positive current collector.
[0048] The positive electrode current collector can be made of aluminum or stainless steel with a surface treated with carbon, nickel, titanium, or silver, or it can be any of the following: membrane, sheet, foil, mesh, porous body, foam, or nonwoven fabric. The positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc.
[0049] This application provides an electrical device that uses a solid-state battery as a power source. The electrical device can be, but is not limited to, vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc.; spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc.; electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc.; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc.
[0050] For ease of explanation, the following embodiments will be described using a vehicle 10 as an example of an electrical device according to an embodiment of this application.
[0051] Please refer to Figure 1Vehicle 10 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A solid-state battery 20 is installed inside vehicle 10, and the solid-state battery 20 can be located at the bottom, front, or rear of vehicle 10. The solid-state battery 20 can be used to power vehicle 10; for example, it can serve as the operating power source for vehicle 10. Vehicle 10 may also include a controller 11 and a motor 12. The controller 11 controls the solid-state battery 20 to supply power to the motor 12, for example, to meet the power needs of vehicle 10 during startup, navigation, and driving.
[0052] In some embodiments of this application, the solid-state battery 20 can not only serve as the operating power source for the vehicle 10, but also as the driving power source for the vehicle 10, replacing or partially replacing fuel or natural gas to provide driving force for the vehicle 10.
[0053] Please refer to Figure 2 and Figure 3 In one embodiment, the density detection method for the solid-state battery 20 includes the following steps:
[0054] S100, stacking negative electrode, solid electrolyte and positive electrode to form stack 21;
[0055] S200, Obtain the initial dimensions of the stack 21;
[0056] S300, The stack 21 is densified to reduce its volume;
[0057] S400, Obtain the shrinkage dimension of the stack 21;
[0058] S500: The dimensional shrinkage rate of the stack 21 is obtained based on the shrinkage size and the initial size of the stack 21, and the density of the solid-state battery 20 is determined based on the dimensional shrinkage rate of the stack 21.
[0059] In the embodiments of this application, in step S100, the negative electrode, solid electrolyte and positive electrode can be stacked, pre-pressed or otherwise formed into a stack body 21, which is also the electrode assembly of the solid battery 20.
[0060] In the embodiments of this application, in step S300, the densification of the stack 21 can be achieved through various pressure operation methods. By applying a certain pressure to the stack 21, the stack 21 undergoes a certain volume deformation, thereby causing the volume of the stack 21 to shrink, increasing the density of the stack 21, and thus providing higher energy density to meet the usage requirements of the solid-state battery 20.
[0061] In the embodiments of this application, in steps S200 and S400, the initial size and shrinkage size of the stack 21 can be obtained by directly measuring with a size detection tool (such as a measuring tape or digital caliper) or by measuring with a displacement sensor.
[0062] In the embodiments of this application, in step S500, the dimensional shrinkage rate of the stack 21 is defined as the ratio of the difference between the initial size and the shrunken size to the initial size, that is, the proportion of the dimensional difference of the stack 21 to the initial size. A lookup table shows a correspondence between the dimensional shrinkage rate of the stack 21 and the density of the solid-state battery 20. Based on the dimensional shrinkage rate of the stack 21, the density of the corresponding solid-state battery 20 can be found, thereby quickly determining the density of the solid-state battery 20.
[0063] The density detection method of the solid-state battery 20 described above further densifies the solid-state battery 20 by densifying the stack 21 to reduce its volume, which facilitates density characterization and subsequent testing of the solid-state battery 20. The dimensional shrinkage rate of the stack 21 is obtained from the shrinkage size and the initial size of the stack 21, and the density of the solid-state battery 20 is determined by the dimensional shrinkage rate of the stack 21. This method improves the situation where destructive operations such as stamping are required to measure the density of the solid-state battery 20, and realizes non-destructive testing of the density of the solid-state battery 20. It can be applied to the batch testing of solid-state batteries 20.
[0064] Please refer to some embodiments in this application. Figure 2 and Figure 4 Before step S200, which involves obtaining the initial dimensions of the stack 21, the following steps are included:
[0065] S201. Pre-compress the stack 21 along the stacking direction to make the negative electrode, solid electrolyte and positive electrode fit tightly together along the stacking direction.
[0066] It should be noted that the stacking direction is... Figure 2 The Z direction shown is the thickness direction of the stack 21.
[0067] In the embodiments of this application, the stack 21 is pre-compressed along the stacking direction in order to make the negative electrode, solid electrolyte and positive electrode fit tightly together along the stacking direction and reduce the gap that may exist between the negative electrode, solid electrolyte and positive electrode in the stacking direction.
[0068] By performing the above settings, the stack 21 is pre-compressed along the stacking direction, which can further densify the solid-state battery 20 and facilitate the density characterization and subsequent testing of the solid-state battery 20.
[0069] Please refer to some embodiments in this application. Figure 4Under the condition of pre-compression treatment, the stack 21 is pre-compressed along the stacking direction, the pre-compression pressure is 0.0294Mpa~0.245Mpa, the pre-compression time is 5min~20min, and the pre-compression ambient temperature is 25℃~150℃.
[0070] It should be noted that, when performing pre-compression treatment, the stack 21 is placed in the pre-compression device, and the stack 21 is pre-compressed along the stacking direction at the pre-compression ambient temperature and with preset pre-compression pressure and pre-compression time, so that the negative electrode, solid electrolyte and positive electrode are tightly attached along the stacking direction.
[0071] Preferably, the pre-compression pressure is 0.0686 MPa, the pre-compression time is 10 min, and the pre-compression ambient temperature is 120℃.
[0072] The above configuration allows the negative electrode, solid electrolyte, and positive electrode to be tightly attached along the stacking direction, thereby achieving further densification of the solid-state battery 20.
[0073] Please refer to some embodiments in this application. Figure 3 The densification of the stack 21 is achieved by performing isostatic pressing or flat pressing on the stack 21.
[0074] In the embodiments of this application, the stack 21 can be densified by performing isostatic pressing to cause a certain volume deformation; or, the stack 21 can be densified by performing flat pressing to cause a certain volume deformation.
[0075] With the above settings, the appropriate method can be selected to densify the stack 21 according to the actual situation.
[0076] Please refer to some embodiments in this application. Figure 5 and Figure 6 The steps for performing isostatic pressing on the stack 21 include:
[0077] S311. Place the stack 21 inside the isostatic pressure container 30;
[0078] S312. The isostatic pressure vessel 30 is filled with isostatic medium 31;
[0079] S313. Apply pressure to the outer periphery of the isostatic container 30 and transmit the pressure to the stack 21 through the isostatic medium 31 so that the volume of the stack 21 shrinks.
[0080] It is understandable that in the step of performing isostatic pressing on the stack 21, the stack 21 is placed in the isostatic container 30, the isostatic container 30 is filled with the isostatic medium 31, the uniform isostatic pressure is applied to the outer surface of the isostatic container 30, and the pressure is transmitted to the stack 21 through the isostatic medium 31 to press the stack 21.
[0081] In the embodiments of this application, steps S311 and S312 can be performed in a specific order, that is, step S311 can be performed first and then step S312, or step S312 can be performed first and then step S311.
[0082] In the embodiments of this application, since pressure is applied to the outer periphery of the isostatic container 30 when isostatic pressing is performed on the stack 21, that is, the stack 21 is compressed in all directions, and the length, thickness and width of the stack 21 will shrink.
[0083] With the above settings, isostatic pressing is performed on the stack 21 to cause a certain volume deformation of the stack 21, thereby achieving further densification of the solid-state battery 20.
[0084] Please refer to some embodiments in this application. Figure 5 and Figure 6 In the step of performing isostatic pressing on the stack 21, the isostatic pressing pressure is 100Mpa~3000Mpa, the isostatic pressing time is 5min~60min, and the isostatic pressing ambient temperature is 25℃~2000℃.
[0085] It should be noted that when performing isostatic pressing on the stack 21, the stack 21 is placed in the isostatic pressing container 30, and the stack 21 is subjected to isostatic pressing treatment at a preset isostatic pressing ambient temperature, using a preset isostatic pressing pressure and isostatic pressing time, so that the stack 21 undergoes a certain volume deformation, thereby achieving the densification treatment of the stack 21.
[0086] The above configuration allows the negative electrode, solid electrolyte, and positive electrode to be tightly attached along the stacking direction, thereby achieving further densification of the solid-state battery 20.
[0087] Please refer to some embodiments in this application. Figure 5 and Figure 6 Under isostatic pressure conditions of 1000 MPa to 3000 MPa, the isostatic ambient temperature is 25℃ to 50℃.
[0088] In the embodiments of this application, the isostatic pressure is relatively high and the isostatic ambient temperature is relatively low, which is cold isostatic pressure. That is, when the pressure inside the isostatic container 30 is high and the temperature is low, uniform isostatic pressure is applied to the outer surface of the stack 21 to press the stack 21.
[0089] With the above settings, under conditions of high pressure and low temperature, the stack 21 is pressurized, and the isostatic medium 31 transmits pressure to the stack 21 so that the volume of the stack 21 shrinks.
[0090] Please refer to some embodiments in this application. Figure 5 and Figure 6 Under isostatic pressure conditions of 300 MPa to 1000 MPa, the isostatic ambient temperature is 50℃ to 200℃.
[0091] In the embodiments of this application, the isostatic pressure and the isostatic ambient temperature are relatively moderate, which is called warm isostatic pressure. That is, when the pressure and temperature inside the isostatic container 30 are moderate, uniform isostatic pressure is applied to the outer surface of the stack 21 to press the stack 21.
[0092] With the above settings, under moderate pressure and temperature, the stack 21 is pressurized, and the isostatic medium 31 transmits pressure to the stack 21, causing the volume of the stack 21 to shrink.
[0093] Please refer to some embodiments in this application. Figure 5 and Figure 6 Under isostatic pressure of 100 MPa to 300 MPa, the isostatic ambient temperature is 200℃ to 2000℃.
[0094] In the embodiments of this application, the isostatic pressure is relatively low and the isostatic ambient temperature is relatively high, which is thermal isostatic pressure. That is, when the pressure inside the isostatic container 30 is low and the temperature is high, uniform isostatic pressure is applied to the outer surface of the stack 21 to press the stack 21.
[0095] With the above settings, the stack 21 is pressurized under low pressure and high temperature conditions, and the isostatic medium 31 transmits pressure to the stack 21 so that the volume of the stack 21 shrinks.
[0096] Please refer to some embodiments in this application. Figure 5 and Figure 6 The isostatic medium 31 is one of esters, water, or inert gases.
[0097] In the embodiments of this application, the isostatic medium 31 is a medium used to transmit pressure and is a material that does not react with the positive and negative electrodes or the solid electrolyte.
[0098] With the above settings, the material of the isostatic medium 31 can be flexibly selected according to the actual situation.
[0099] Please refer to some embodiments in this application. Figure 7 and Figure 8 The steps for performing a flattening operation on the stack 21 include:
[0100] S321. Place the stack 21 between the two pressure blocks 40;
[0101] S322. Apply pressure to the two pressure blocks 40 and transmit the pressure to the stack 21 through the two pressure blocks 40 so that the volume of the stack 21 shrinks.
[0102] Understandably, in the step of performing the flat pressing operation on the stack 21, the stack 21 is placed between two pressure blocks 40, and pressure is applied to the two pressure blocks 40 so that the two pressure blocks 40 clamp the stack 21 to press the stack 21.
[0103] In the embodiments of this application, when a flat pressing operation is performed on the stack 21, the two pressing blocks 40 clamp the stack 21 along a preset direction, so that the stack 21 shrinks in size in the preset direction, which is any one of length, thickness, and width. For example, the two pressing blocks 40 clamp the stack 21 along the thickness direction of the stack 21, at which time the stack 21 shrinks in size in the thickness direction.
[0104] By using the above settings, a flat pressing operation is performed on the stack 21 to cause a certain volume deformation of the stack 21, thereby achieving further densification of the solid-state battery 20.
[0105] Please refer to some embodiments in this application. Figure 7 and Figure 8 In the step of performing flattening operation on the stack 21, the flattening pressure is 9.84Mpa~73.54Mpa, the flattening time is 1min~20min, and the flattening ambient temperature is 50℃~300℃.
[0106] It should be noted that when performing a flat pressing operation on the stack 21, the stack 21 is placed between two pressing blocks 40. Under a preset flat pressing ambient temperature, the stack 21 is subjected to flat pressing treatment using a preset flat pressing pressure and flat pressing time, so that the stack 21 undergoes a certain volume deformation, thereby achieving the densification treatment of the stack 21.
[0107] By setting the above, the stack 21 shrinks in size in a preset direction, thereby causing a certain volume deformation of the stack 21.
[0108] Please refer to some embodiments in this application. Figure 7 and Figure 8 At least one pressure block 40 is provided with a heating element.
[0109] It is understandable that by setting a heating element inside the pressure block 40, the pressure block 40 will gradually heat up and transfer heat to the stack body 21 when it is powered on, so that the preset flat pressing environment temperature can be reached during the flat pressing operation.
[0110] In the embodiments of this application, a heating element may be provided in only one of the pressing blocks 40, or a heating element may be provided in both pressing blocks 40.
[0111] With the above settings, when the power is on, the pressing block 40 will gradually heat up and transfer the heat to the stack 21 so that the preset pressing environment temperature can be reached during the pressing operation.
[0112] Please refer to Figure 2 In one embodiment, the solid-state battery 20 is prepared using the density detection method for solid-state battery 20 described above.
[0113] It should be noted that the solid-state battery 20 includes not only the negative electrode, solid electrolyte and positive electrode, but also other components such as the casing and terminals.
[0114] The solid-state battery 20 described above obtains the dimensional shrinkage rate of the stack 21 based on the shrinkage size and the initial size of the stack 21, and determines the density of the solid-state battery 20 based on the dimensional shrinkage rate of the stack 21. This improves the situation where destructive operations such as stamping are required to measure the density of the solid-state battery 20, and realizes non-destructive testing of the density of the solid-state battery 20, which can be applied to the batch testing of the solid-state battery 20.
[0115] Please refer to Figure 1 In one embodiment, the electrical device includes the solid-state battery 20 described above.
[0116] The aforementioned electrical equipment enables non-destructive testing of the density of the solid-state battery 20, and can be applied to the batch testing of the solid-state battery 20, which is beneficial to the battery life stability of the electrical equipment.
[0117] According to some embodiments in this application, see Figures 2 to 8 This application provides a density detection method for a solid-state battery 20, comprising the following steps: stacking a negative electrode, a solid electrolyte, and a positive electrode to form a stack 21; pre-compressing the stack 21 along the stacking direction to make the negative electrode, solid electrolyte, and positive electrode adhere tightly along the stacking direction; obtaining the initial size of the stack 21; performing a densification process on the stack 21 to shrink the volume of the stack 21; obtaining the shrinkage size of the stack 21; obtaining the size shrinkage rate of the stack 21 based on the shrinkage size and the initial size of the stack 21, and determining the density of the solid-state battery 20 based on the size shrinkage rate of the stack 21.
[0118] The densification of the stack 21 is achieved by performing isostatic pressing or flattening operations on the stack 21. The steps of performing isostatic pressing on the stack 21 include: placing the stack 21 in an isostatic container 30; filling the isostatic container 30 with an isostatic medium 31; applying pressure to the outer periphery of the isostatic container 30 and transmitting the pressure to the stack 21 through the isostatic medium 31 to cause the volume of the stack 21 to shrink; wherein the isostatic pressure is 100 MPa to 3000 MPa, the isostatic pressing time is 5 min to 60 min, the isostatic pressing ambient temperature is 25℃ to 2000℃, and the isostatic medium 31 is one of esters, water, or inert gases. The steps of performing a flattening operation on the stack 21 include: placing the stack 21 between two pressure blocks 40; applying pressure to the two pressure blocks 40 and transmitting the pressure to the stack 21 through the two pressure blocks 40 to cause the volume of the stack 21 to shrink; wherein the flattening pressure is 9.84 MPa to 73.54 MPa, the flattening time is 1 min to 20 min, and the flattening ambient temperature is 50℃ to 300℃.
[0119] According to some embodiments in this application, see Figure 2 This application provides a solid-state battery 20, which is prepared using the density detection method for solid-state battery 20 described above.
[0120] According to some embodiments in this application, see Figure 1 This application provides an electrical device, which includes the solid-state battery 20 described above.
[0121] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.
Claims
1. A method for detecting the density of a solid-state battery (20), characterized in that, Includes the following steps: Stacking the negative electrode, solid electrolyte and positive electrode to form a stack (21). Obtain the initial dimensions of the stack (21); The stack (21) is densified to reduce its volume; Obtain the shrinkage dimension of the stack (21); The dimensional shrinkage rate of the stack (21) is obtained based on the shrinkage size and the initial size of the stack (21), and the density of the solid-state battery (20) is determined by the dimensional shrinkage rate of the stack (21).
2. The density detection method for solid-state battery (20) according to claim 1, characterized in that, Prior to obtaining the initial dimensions of the stack (21), the following steps are included: The stack (21) is pre-compressed along the stacking direction so that the negative electrode, the solid electrolyte and the positive electrode are in close contact along the stacking direction.
3. The density detection method for solid-state battery (20) according to claim 2, characterized in that, When pre-compression is performed, the stack (21) is pre-compressed along the stacking direction. The pre-compression pressure is 0.0294 MPa to 0.245 MPa, the pre-compression time is 5 min to 20 min, and the pre-compression ambient temperature is 25℃ to 150℃.
4. The density detection method for solid-state battery (20) according to claim 1, characterized in that, The densification of the stack (21) is achieved by performing isostatic pressing or flat pressing on the stack (21).
5. The density detection method for solid-state battery (20) according to claim 4, characterized in that, The steps of performing isostatic pressing on the stack (21) include: The stack (21) is placed inside an isostatic pressure vessel (30); The isostatic pressure vessel (30) is filled with an isostatic medium (31); Pressure is applied to the outer periphery of the isostatic container (30) and transmitted to the stack (21) through the isostatic medium (31) to cause the volume of the stack (21) to shrink.
6. The density detection method for solid-state battery (20) according to claim 5, characterized in that, In the step of performing isostatic pressing on the stack (21), the isostatic pressure is 100Mpa~3000Mpa, the isostatic pressing time is 5min~60min, and the isostatic pressing ambient temperature is 25℃~2000℃.
7. The density detection method for solid-state battery (20) according to claim 6, characterized in that, When the isostatic pressure is 1000 MPa to 3000 MPa, the isostatic ambient temperature is 25°C to 50°C.
8. The density detection method for solid-state battery (20) according to claim 6, characterized in that, When the isostatic pressure is 300 MPa to 1000 MPa, the isostatic ambient temperature is 50°C to 200°C.
9. The density detection method for a solid-state battery (20) according to claim 6, characterized in that, When the isostatic pressure is 100 MPa to 300 MPa, the isostatic ambient temperature is 200°C to 2000°C.
10. The density detection method for a solid-state battery (20) according to claim 6, characterized in that, The isostatic medium (31) is one of esters, water, or inert gases.
11. The density detection method for a solid-state battery (20) according to claim 4, characterized in that, The steps of performing a flattening operation on the stack (21) include: The stack (21) is placed between two pressure blocks (40); Pressure is applied to the two pressure blocks (40) and the pressure is transmitted to the stack (21) through the two pressure blocks (40) to cause the volume of the stack (21) to shrink.
12. The density detection method for a solid-state battery (20) according to claim 11, characterized in that, In the step of performing a flattening operation on the stack (21), the flattening pressure is 9.84 MPa to 73.54 MPa, the flattening time is 1 min to 20 min, and the flattening ambient temperature is 50℃ to 300℃.
13. The density detection method for the solid-state battery (20) according to claim 11, characterized in that, At least one of the pressing blocks (40) is provided with a heating element.
14. A solid-state battery (20), characterized in that, The solid-state battery (20) was prepared using the density detection method described in any one of claims 1-13.
15. An electrical appliance, characterized in that, Includes the solid-state battery (20) as described in claim 14.