Battery monomer, battery device and electric equipment

Abstract

The utility model relates to the technical field of battery equipment, and discloses a battery monomer, a battery device and electric equipment. Wherein the battery monomer comprises a shell, an electrode assembly and at least one pressurizing piece, the shell is provided with a containing space, the electrode assembly is arranged in the containing space, the electrode assembly comprises multiple layers of electrode plates and multiple layers of solid electrolyte layers, and the multiple layers of electrode plates and the multiple layers of solid electrolyte layers are sequentially and alternately stacked in the first direction; a pressurizing piece is arranged between at least one end, in the first direction, of the electrode assembly and the shell, the pressurizing piece has a zero-rigidity characteristic deformation range, and the pressurizing piece applies extrusion force to the electrode assembly in the zero-rigidity characteristic deformation range. The technical scheme of the utility model aims to solve the problem of non-uniform pressure caused by expansion and contraction cycles of an electrode assembly of a current solid-state battery during charge-discharge cycles.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of battery equipment, and particularly relates to a battery monomer, a battery device and an electric equipment. BACKGROUND

[0002] In the battery monomer in the form of solid-state laminates, the electrode sheets of the electrode assembly and the solid-state electrolyte layer are tightly combined to ensure the tightness of the solid-solid contact interface between the solid-state electrolyte layer and the active material layer on the electrode sheet. However, in the process of charging and discharging of the battery monomer, the electrode assembly will expand due to heat, and after the battery monomer stops charging and discharging, the electrode assembly will shrink due to cooling, which causes the pressure between the electrode sheets of the electrode assembly and the solid-state electrolyte layer to be uneven. Mainly, when the electrode assembly expands, the pressure is too large, which will cause the local current density to be too large, cause more metal deposition in the local area to form metal dendrites, and the metal dendrites are easy to penetrate through the solid-state electrolyte layer to cause the risk of short circuit. Moreover, the expansion and contraction cycle of long-term use will change the solid-solid contact interface between the solid-state electrolyte layer and the active material layer on the electrode sheet in the electrode assembly, causing the electrochemical performance to rapidly decay, and affecting the service life of the battery monomer. CONTENT OF THE UTILITY MODEL

[0003] The application aims to provide a battery monomer, a battery device and an electric equipment, and aims to solve the problem of uneven pressure caused by the expansion and contraction cycle of the electrode assembly of the current solid-state battery during the charging and discharging cycle.

[0004] To achieve the above-mentioned purpose, according to the first aspect of the embodiment of the application, a battery monomer is provided, which comprises a shell, an electrode assembly and at least one pressure piece, the shell has a containing space, the electrode assembly is arranged in the containing space, the electrode assembly comprises a plurality of layers of electrode sheets and a plurality of layers of solid-state electrolyte layers, the plurality of layers of electrode sheets and the plurality of layers of solid-state electrolyte layers are arranged in the first direction and are alternately stacked in sequence, and the pressure piece is arranged between at least one end of the electrode assembly in the first direction and the shell, wherein the pressure piece has a zero stiffness characteristic deformation range, and the pressure piece applies extrusion pressure to the electrode assembly in the zero stiffness characteristic deformation range.

[0005] In the battery cell, the pressure applying member applies pressure to the electrode sheet and the solid-state electrolyte layer in the electrode assembly, so that the solid-state electrolyte layer and the electrode sheet can be kept in close contact, i.e., the tightness of the solid-solid contact interface between the solid-state electrolyte layer and the active material layer on the electrode sheet is ensured. Moreover, the pressure applying member has a zero-stiffness characteristic deformation range, and in the assembled battery cell, the pressure applying member applies extrusion pressure to the electrode assembly within the zero-stiffness characteristic deformation range. In this way, during the charging and discharging process of the battery cell, the pressure applying member is extruded and deformed with the expansion of the electrode assembly, and the pressure applying member is extruded and deformed within the zero-stiffness characteristic deformation range, and when the electrode assembly cools and shrinks, the pressure applying member is still extruded and deformed within the zero-stiffness characteristic deformation range, so the extrusion pressure applied by the pressure applying member to the electrode assembly remains unchanged (or the change in extrusion pressure is very small, almost negligible, which can be considered as the extrusion pressure remains unchanged). That is, during the charging and discharging process of the battery cell, the electrode assembly is subjected to constant extrusion pressure applied by the pressure applying member, and the stress is uniform throughout the charging and discharging process, thereby reducing the possibility of local metal deposition forming metal dendrites in the electrode assembly, reducing the risk of short circuit, and keeping the solid-solid contact interface between the solid-state electrolyte layer and the active material layer on the electrode sheet in the electrode assembly in close contact, which is beneficial to slow down the electrochemical performance decay rate and prolong the service life of the battery cell.

[0006] In some embodiments, the extrusion pressure applied by the pressure applying member to the electrode assembly is ΔF1, and the required pre-tightening extrusion pressure of the electrode assembly is ΔF2, where ΔF2·(1-10%)≤ΔF1≤ΔF2·(1+10%).

[0007] In some embodiments, the housing includes a first shell and a second shell, the first shell and the second shell are overlapped with each other along a first direction to form a containing space, and the pressure applying member is arranged between one end of the electrode assembly along the first direction and the first shell, and / or the pressure applying member is arranged between the other end of the electrode assembly along the first direction and the second shell.

[0008] In some embodiments, along the first direction, the projection of the electrode sheet has a circular contour shape, the projection of the solid-state electrolyte layer has a circular contour shape, and the projection of the electrode sheet coincides with the projection of the solid-state electrolyte layer. Moreover, along the first direction, the projection of the housing has a circular contour shape, and the contour projection of the containing space of the housing coincides with the projection of the electrode sheet. In this way, in the battery cell, the electrode assembly can make full use of the containing space of the housing, thereby facilitating the improvement of the volumetric energy density of the battery cell.

[0009] In some embodiments, the battery cell further comprises an adapter, the adapter is arranged between the pressing member and the electrode assembly, and the adapter is arranged along the first direction, one side of the adapter is attached to the end surface of the electrode assembly, and the other side of the adapter is connected with the pressing member. Through the adapter, both ends of the electrode assembly are subjected to uniform extrusion force. During the charging and discharging process of the battery cell, the extrusion force applied to the electrode assembly by the pressing member is always constant, and the electrode assembly is uniformly stressed during the entire charging and discharging process, thereby reducing the possibility of local metal deposition forming metal dendrites in the electrode assembly, reducing the risk of short circuit, and making the solid-solid contact interface between the solid electrolyte layer and the active material layer on the electrode sheet in the electrode assembly always tightly combined, which is beneficial to slowing down the electrochemical performance decay rate and prolonging the service life of the battery cell.

[0010] In some embodiments, the pressing member comprises a disc spring, and the disc spring is pre-tightened and compressed between the adapter and the shell.

[0011] In some embodiments, the center axis of the disc spring coincides with the center axis of the electrode assembly. In this way, the disc spring uniformly applies extrusion force to the electrode assembly at all positions around the center axis of the electrode assembly, so that the electrode assembly is uniformly stressed during the entire charging and discharging process.

[0012] In some embodiments, each pressing member comprises a plurality of disc springs, the disc springs have recessed spaces, and the disc springs are arranged in a recessed direction consistent manner. In this way, the number of disc springs can be stacked according to the required extrusion force strength of the electrode assembly, so as to meet the extrusion force strength requirement. That is, the number of disc springs can be adaptively stacked for different battery cells with different extrusion force strength requirements, which has good flexibility.

[0013] According to a second aspect of embodiments of the present application, a battery device is provided. The battery device comprises the battery cell as described above, and the battery cell is used for storing or providing electric energy.

[0014] According to a third aspect of embodiments of the present application, a power consuming device is provided. The power consuming device comprises a power consuming load, and

[0015] The power consuming device further comprises a plurality of battery cells as described above, and the power consuming load is electrically connected with the plurality of battery cells.

[0016] Alternatively, the power consuming device further comprises a battery device as described above, and the power consuming load is electrically connected with the battery device. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments, and other drawings can be obtained by those skilled in the art without creative effort based on these drawings.

[0018] Figure 1 A decomposition schematic view of a battery cell according to an embodiment of the present application;

[0019] Figure 2 A decomposition schematic view of another battery cell according to an embodiment of the present application;

[0020] Figure 3 A decomposition schematic view of still another battery cell according to an embodiment of the present application;

[0021] Figure 4 A decomposition schematic view of yet another battery cell according to an embodiment of the present application;

[0022] Figure 5 A cross-sectional schematic view of a pressure member of a battery cell according to an embodiment of the present application;

[0023] Figure 6 A Figure 5 A rigidity characteristic curve diagram of the pressure member shown;

[0024] Figure 7 A structural schematic view of a battery device according to an embodiment of the present application;

[0025] Figure 8 A structural schematic view of an electric device according to an embodiment of the present application.

[0026] In the drawings, various reference numerals are used throughout the drawings. As used in the description of the drawings, the following numbers represent the following list of elements:

[0027] 100, battery cell; 101, electrode terminal;

[0028] 10, housing; 11, first housing; 12, second housing; 13, accommodation space;

[0029] 20, electrode assembly; 21, electrode sheet; 210, active material layer; 211, cathode active material layer; 212, anode active material layer; 213, current collector; 22, solid electrolyte layer; 23, central axis of the electrode assembly;

[0030] 30, pressure member; 31, central axis of the disc spring; 32, recessed space;

[0031] 40, adapter;

[0032] 200, battery device; 201, case main body; 202, case cover; 203, assembly space

[0033] 400, electric device; 410, electric load; 420, control device; 430, vehicle frame; 440, vehicle wheel. DETAILED DESCRIPTION

[0034] Embodiments of the present application are described below in detail with reference to examples thereof shown in the attached drawings, wherein the same or similar components or components having the same or similar functions are denoted by the same or similar reference numerals throughout. The embodiments described below by reference to the drawings are exemplary and are intended to explain the present application, and cannot be understood as limiting the present application.

[0035] In the description of the present application, it is to be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0036] In addition, the terms "first", "second", and the like are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second", and the like can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0037] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be broadly understood, for example, can be fixedly connected, or can be detachably connected, or can be integrated; can be mechanically connected, or can be electrically connected; can be directly connected, or can be indirectly connected through an intermediate medium; can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0038] From a market perspective, the application of new energy battery devices is becoming increasingly widespread. These devices are not only used in energy storage power systems such as hydropower, thermal power, wind power, and solar power plants (these battery devices are generally referred to as energy storage batteries), but also widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars (these battery devices are generally referred to as power batteries). As the application areas of battery devices continue to expand, the market demand is also constantly increasing.

[0039] Currently, battery devices on the market widely use liquid electrolyte battery cells for assembly and production. However, with the continuous development and improvement of new energy battery technology, solid electrolyte battery cells have advantages over liquid electrolyte battery cells, including higher volumetric energy density, greater safety, high-rate fast charging, less performance degradation at low temperatures, and simplified structure. Therefore, solid electrolyte battery cells have good application potential.

[0040] In related technologies, in solid-state stacked battery cells, the electrode plates and solid electrolyte layer of the electrode assembly are tightly bonded to ensure a tight solid-solid contact interface between the solid electrolyte layer and the active material layer on the electrode plate. However, during the charging and discharging process of the battery cell, the electrode assembly undergoes thermal expansion, and after the battery cell stops charging and discharging, the electrode assembly cools and contracts. This leads to uneven pressure between the electrode plates and the solid electrolyte layer. Specifically, excessive pressure during electrode expansion can cause excessively high local current density, resulting in more local metal deposition and the formation of metal dendrites. These metal dendrites can easily penetrate the solid electrolyte layer, posing a short-circuit risk. Furthermore, long-term expansion and contraction cycles can alter the solid-solid contact interface between the solid electrolyte layer and the active material layer on the electrode plate, causing rapid degradation of electrochemical performance and affecting the lifespan of the battery cell.

[0041] Based on the above considerations, embodiments of this application provide a single battery cell, which is a solid-state battery using a solid electrolyte. In this battery cell, a pressure-applying component applies pressure to the stacked electrode sheets and solid electrolyte layer in the electrode assembly, thereby ensuring a tight bond between the solid electrolyte layer and the electrode sheets, i.e., guaranteeing the tightness of the solid-solid contact interface between the solid electrolyte layer and the active material layer on the electrode sheets. Furthermore, the pressure-applying component used in this battery cell has a zero-stiffness characteristic deformation range. In the assembled battery cell, the pressure-applying component applies extrusive force to the electrode assembly within its zero-stiffness characteristic deformation range. Thus, during the charging and discharging process of the battery cell, the pressure-applying component undergoes extrusive deformation as the electrode assembly expands, and this extrusive deformation occurs within its zero-stiffness characteristic deformation range. Moreover, when the electrode assembly cools and contracts, the pressure-applying component still undergoes extrusive deformation within its zero-stiffness characteristic deformation range. Therefore, the extrusive force applied by the pressure-applying component to the electrode assembly remains constant (or the extrusive force variation remains within a reasonable error range, which can be considered as the extrusive force remaining constant). In other words, during the charging and discharging process of a single battery cell, the compressive force applied by the pressurizing component to the electrode assembly remains constant, and the force is uniform throughout the entire charging and discharging process. This reduces the possibility of local metal deposition and the formation of metal dendrites in the electrode assembly, thereby reducing the risk of short circuits. Furthermore, it ensures that the solid-solid contact interface between the solid electrolyte layer and the active material layer on the electrode sheet remains tightly bonded, which helps to slow down the rate of electrochemical performance degradation and extend the service life of the battery cell.

[0042] To illustrate the technical solutions provided by the embodiments of this application, the following detailed description is provided in conjunction with specific drawings and embodiments.

[0043] like Figures 1 to 4 The diagram shows a rectangular coordinate system, where the X-axis represents the first direction X, the Y-axis represents the second direction Y, and the Z-axis represents the third direction Z. Furthermore, the first direction X, the second direction Y, and the third direction Z are all perpendicular to each other.

[0044] According to a first aspect of the embodiments of this application, embodiments of this application provide a single battery cell. For example... Figures 1 to 5As shown, the battery cell 100 includes a housing 10, an electrode assembly 20, and at least one pressure member 30. The housing 10 has a receiving space 13, and the electrode assembly 20 is disposed in the receiving space 13. The electrode assembly 20 includes multiple electrode sheets 21 and multiple solid electrolyte layers 22. The multiple electrode sheets 21 and multiple solid electrolyte layers 22 are alternately stacked along a first direction X. A pressure member 30 is provided between at least one end of the electrode assembly 20 along the first direction X and the housing 10. The pressure member 30 has a zero stiffness characteristic deformation range, and the pressure member 30 applies a compressive force to the electrode assembly 20 within the zero stiffness characteristic deformation range.

[0045] "Zero stiffness characteristic" refers to the property of a material or structure that does not produce elastic deformation when subjected to force, commonly known as zero stiffness. Taking an ideal spring with a zero stiffness characteristic deformation range as an example, when the spring is in the zero stiffness characteristic deformation range, when the spring continues to be compressed or stretched within its zero stiffness characteristic deformation range, it is not that the spring is "weak". Rather, if you continue to compress or stretch it, the relative distance between its two ends continues to decrease or increase, but the external force required remains unchanged. In other words, the elastic force it exerts on the outside remains unchanged.

[0046] In the embodiments of this application, the compressive force applied by the pressure member 30 to the electrode assembly 20 is ΔF1, and the required pre-tightening compressive force of the electrode assembly 20 is ΔF2, wherein ΔF2·(1-10%)≤ΔF1≤ΔF2·(1+10%). The required pre-tightening compressive force ΔF2 of the electrode assembly 20 is one of the parameters determined in the design and manufacture of the battery cell 100. It is determined comprehensively based on factors such as the material type of the solid electrolyte layer 22, the surface roughness of the solid electrolyte layer 22, and the surface roughness of the active material layer 210 of the electrode sheet 21. In fact, the deformation elastic force of the pressure member 30 used in the battery cell 100 of this application when deformed within its zero stiffness characteristic deformation range is not ideally constant, but rather increases or decreases within a reasonable error range, in conjunction with [see [reference]]. Figure 6 As shown. Therefore, based on the required pre-tightening extrusion force of the electrode assembly 20 being ΔF2, that is, the magnitude of the initial extrusion force applied by the pressure member 30 to the electrode assembly 20 when assembling and producing the battery cell 100 is ΔF2, when the pressure member 30 deforms within its zero stiffness characteristic deformation range, the magnitude of the extrusion force applied by the pressure member 30 to the electrode assembly 20 conforms to ΔF2·(1-10%)≤ΔF1≤ΔF2·(1+10%).

[0047] like Figures 1 to 4As shown, the electrode sheet 21 includes a current collector 213 and an active material layer 210. The active material layer 210 is coated on both sides of the current collector 213. One side of the current collector 213 is coated with a cathode active material layer 211, and the other side is coated with an anode active material layer 212. This design of the electrode sheet 21 is called a "one-piece bipolar" design. In the electrode assembly 20, multiple layers of electrode sheets 21 and multiple layers of solid electrolyte layers 22 are alternately stacked along the first direction X. Therefore, the tabs of the electrode assembly 20 are no longer located at the ends of the electrode assembly 20 along the first direction X. Instead, the current collector 213 extends laterally from a direction perpendicular to the first direction X to electrically connect with the electrode terminals 101 of the battery cell 100. Furthermore, the tabs must avoid the pressure-applying member 30 when extending towards the electrode terminals 101. The "lateral" direction can be any direction perpendicular to the first direction X, for example, it can be... Figures 1 to 4 The second direction Y shown can also be as follows: Figures 1 to 4 The third direction Z shown can also be any other direction perpendicular to the first direction X, and is not limited to this one.

[0048] In this battery cell 100, pressure is applied to the electrode sheets 21 and the solid electrolyte layer 22 stacked in the electrode assembly 20 by a pressure-applying component 30, thereby ensuring a tight bond between the solid electrolyte layer 22 and the electrode sheets 21, that is, ensuring the tightness of the solid-solid contact interface between the solid electrolyte layer 22 and the active material layer 210 on the electrode sheets 21. Furthermore, the pressure-applying component 30 used in this battery cell 100 has a zero-stiffness deformation range. In the assembled battery cell 100, the pressure-applying component 30 applies compressive force to the electrode assembly 20 within its zero-stiffness deformation range. Thus, during the charging and discharging process of the battery cell 100, the pressure-applying component 30 expands and deforms under pressure as the electrode assembly 20 expands. This deformation occurs within its zero-stiffness characteristic deformation range. Furthermore, even after the electrode assembly 20 cools and contracts, the pressure-applying component 30 remains within its zero-stiffness characteristic deformation range. Therefore, the compressive force exerted by the pressure-applying component 30 on the electrode assembly 20 remains constant (or the compressive force variation remains within a reasonable error range, which can be considered as constant). In other words, during the charging and discharging process of the battery cell 100, the compressive force exerted on the electrode assembly 20 by the pressure-applying component 30 remains constant. The electrode assembly 20 experiences uniform stress throughout the entire charging and discharging process, thereby reducing the possibility of localized metal deposition and the formation of metal dendrites in the electrode assembly 20, reducing the risk of short circuits. Moreover, it ensures that the solid-solid contact interface between the solid electrolyte layer 22 and the active material layer 210 on the electrode sheet 21 in the electrode assembly 20 remains tightly bonded, which helps slow down the rate of electrochemical performance degradation and extends the service life of the battery cell 100.

[0049] like Figures 1 to 4 As shown, the outer casing 10 of this embodiment includes a first casing 11 and a second casing 12, which are fitted together along a first direction X to form a receiving space 13. Multilayer electrode sheets 21 and multilayer solid electrolyte layers 22 are alternately stacked along the first direction X within one of the first casing 11 and the second casing 12. After the pressure member 30 is installed, the other casing is fitted together, and the seam between the first casing 11 and the second casing 12 is sealed.

[0050] The following description uses the example of "alternatingly stacking multilayer electrode sheets 21 and multilayer solid electrolyte layers 22 along the first direction X inside the first housing 11, and then covering the first housing 11 with the second housing 12". Here, the first housing 11 is a housing with one open end and the other closed, and the second housing 12 is essentially an end cap.

[0051] like Figure 2 As shown, in some embodiments, the pressure member 30 is disposed between one end of the electrode assembly 20 along the first direction X and the first housing 11. In this embodiment, the pressure member 30 is first placed into the bottom of the closed end of the first housing 11, and then multiple layers of electrode sheets 21 and multiple layers of solid electrolyte layers 22 are alternately stacked along the first direction X. After the electrode sheets 21 and solid electrolyte layers 22 are stacked, the tabs extending from the current collector 213 are electrically connected to the electrode terminals 101. Then, the second housing 12 is closed onto the open end of the first housing 11, and the second housing 12 abuts against the corresponding end of the electrode assembly 20. Subsequently, the electrode assembly 20 compresses the pressure member 30 to achieve its zero stiffness characteristic deformation range to generate compressive force.

[0052] like Figure 1 As shown, in some embodiments, the pressure member 30 is disposed between the other end of the electrode assembly 20 along the first direction X and the second housing 12. In this embodiment, multiple layers of electrode sheets 21 and multiple layers of solid electrolyte layers 22 are sequentially and alternately stacked along the first direction X on the bottom of the closed end of the first housing 11. After the electrode sheets 21 and solid electrolyte layers 22 are stacked, the pressure member 30 is placed on the end face of the electrode assembly 20 facing the open end of the first housing 11. Then, the tabs extending from the current collector 213 are electrically connected to the electrode terminals 101. Then, the second housing 12 is closed onto the open end of the first housing 11, and the second housing 12 abuts against the pressure member 30, thereby directly compressing the pressure member 30 to make its compression deformation reach its zero stiffness characteristic deformation range to generate compressive force.

[0053] like Figure 3As shown, in some embodiments, pressure members 30 are provided between one end of the electrode assembly 20 along the first direction X and the first housing 11, and between the other end of the electrode assembly 20 along the first direction X and the second housing 12. In this embodiment, one pressure member 30 is first placed into the bottom of the closed end of the first housing 11, and then multiple layers of electrode sheets 21 and multiple layers of solid electrolyte layers 22 are alternately stacked along the first direction X. After the electrode sheets 21 and solid electrolyte layers 22 are stacked, another pressure member 30 is placed on the end face of the electrode assembly 20 facing the open end of the first housing 11. Then, the tabs extending from the current collector 213 are electrically connected to the electrode terminal 101. Next, the second housing 12 is closed onto the open end of the first housing 11, and the second housing 12 abuts against the corresponding pressure member 30, thereby squeezing the two pressure members 30 so that both pressure members 30 are compressed and deformed to their zero stiffness characteristic deformation range to generate extrusion force. Thus, both ends of the electrode assembly 20 are subjected to uniform extrusion pressure. During the charging and discharging process of the battery cell 100, the extrusion pressure applied by the pressure-applying component 30 to the electrode assembly 20 remains constant. The electrode assembly 20 is subjected to uniform force throughout the entire charging and discharging process, which reduces the possibility of local metal deposition and the formation of metal dendrites in the electrode assembly 20, reduces the risk of short circuit, and ensures that the solid-solid contact interface between the solid electrolyte layer 22 and the active material layer 210 on the electrode sheet 21 in the electrode assembly 20 is always tightly bonded. This helps to slow down the rate of electrochemical performance degradation and extends the service life of the battery cell 100.

[0054] In some embodiments, along the first direction X, the outline of the projected electrode sheet 21 is circular, the outline of the projected solid electrolyte layer 22 is circular, and the projections of the electrode sheet 21 and the solid electrolyte layer 22 coincide. Furthermore, along the first direction X, the outline of the projected housing 10 is circular, and the projection of the outline of the housing space 13 of the housing 10 coincides with the projection of the electrode sheet 21. That is, the battery cell 100 in this embodiment is a cylindrical cell, also referred to as a cylindrical battery. In this way, the electrode assembly 20 can fully utilize the housing space 13 of the housing 10, thereby improving the volumetric energy density of the battery cell 100.

[0055] Of course, the battery cell 100 in this application can also be a square cell, that is, a square battery.

[0056] In the embodiments of this application, the battery cell 100 can be a secondary battery, which refers to a battery cell 100 that can be used again after being discharged by recharging to activate the active material layer.

[0057] In order for the pressure-applying component 30 to apply uniform compressive force to various positions on the end face of the electrode assembly 20, such as Figures 1 to 3As shown, in some embodiments, the battery cell 100 further includes an adapter 40, which is disposed between the pressure member 30 and the electrode assembly 20. Along the first direction X, one side of the adapter 40 is attached to the end face of the electrode assembly 20, and the other side of the adapter 40 is connected to the pressure member 30. The adapter 40 can be a rigid plate, and one surface of the rigid plate is tightly fitted to the end face of the electrode assembly 20. Thus, the pressure member 30 transmits the compressive force to the rigid plate adapter 40, and then the adapter 40 evenly transmits the compressive force to various positions on the end face of the electrode assembly 20, meaning that the entire end face of the electrode assembly 20 is uniformly subjected to the compressive force. Thus, both ends of the electrode assembly 20 are subjected to uniform extrusion pressure. During the charging and discharging process of the battery cell 100, the extrusion pressure applied by the pressure-applying component 30 to the electrode assembly 20 remains constant. The electrode assembly 20 is subjected to uniform force throughout the entire charging and discharging process, which reduces the possibility of local metal deposition and the formation of metal dendrites in the electrode assembly 20, reduces the risk of short circuit, and ensures that the solid-solid contact interface between the solid electrolyte layer 22 and the active material layer 210 on the electrode sheet 21 in the electrode assembly 20 is always tightly bonded. This helps to slow down the rate of electrochemical performance degradation and extends the service life of the battery cell 100.

[0058] like Figures 1 to 5 As shown, in some embodiments, the pressure member 30 includes a disc spring, which is pre-compressed and disposed between the adapter 40 and the housing 10. For example... Figure 6 As shown, when the compression of the disc spring is between 4mm and 6mm, the disc spring applies a compressive force to the electrode assembly 20 within its zero stiffness characteristic deformation range. This means the compressive force applied by the disc spring to the electrode assembly 20 remains essentially constant, ensuring uniform stress on the electrode assembly 20 throughout the charging and discharging process. This reduces the possibility of localized metal deposition and the formation of metal dendrites in the electrode assembly 20, lowering the risk of short circuits. Furthermore, it ensures a tight bond between the solid electrolyte layer 22 and the active material layer 210 on the electrode sheet 21, which helps slow down the rate of electrochemical performance degradation and extends the lifespan of the battery cell 100. If the spring force within its zero stiffness characteristic deformation range is less than the required pre-tightening compressive force ΔF2 for the electrode assembly 20, simply increasing the thickness of the disc spring will increase its spring force within its zero stiffness characteristic deformation range to meet the requirement of ΔF2·(1-10%)≤ΔF1≤ΔF2·(1+10%).

[0059] In order for the disc spring to apply uniform compressive force to various positions on the end face of the electrode assembly 20, such as Figures 1 to 5As shown, in some embodiments, the central axis 31 of the disc spring coincides with the central axis 23 of the electrode assembly. That is, the disc spring is located at the middle position of the end face of the electrode assembly 20, and the disc spring applies a uniform compressive force to all circumferential positions of the electrode assembly 20 around the central axis 23 of the electrode assembly, so that the electrode assembly 20 is subjected to uniform force throughout the entire charging and discharging process.

[0060] In some embodiments, if the spring force of the disc spring within its zero stiffness characteristic deformation range is less than the preload pressure ΔF2 required for the electrode assembly 20, in addition to increasing the thickness of the disc spring, such as... Figure 4 As shown, this application can also satisfy the requirement by having each pressure member 30 include multiple disc springs. Wherein, as Figure 4 and Figure 5 As shown, the disc spring has a recessed space 32, and multiple disc springs are stacked in the same recessed direction as the recessed space 32. This allows the number of disc springs to be stacked according to the required compressive strength of the electrode assembly 20, thereby achieving the desired compressive strength. In other words, the number of disc springs can be adaptively stacked for different battery cells 100 with different compressive strength requirements, providing good flexibility.

[0061] According to a second aspect of the embodiments of this application, embodiments of this application also provide a battery device 200, such as... Figure 7 As shown, the battery device 200 includes a main body 201, a cover 202, and multiple battery cells 100 as described above. The cover 202 closes onto the open end of the main body 201, forming an assembly space 203. Multiple battery cells 100 are arrayed and assembled within the assembly space 203. The battery cells 100 are used for storing electrical energy or supplying power.

[0062] According to a third aspect of the embodiments of this application, embodiments of this application also provide an electrical device 400, which includes an electrical load 410.

[0063] Electrical equipment 400 includes, but is not limited to, electric toys, power tools, electric vehicles, electric cars, ships, and spacecraft. Electric toys may include, but are not limited to, stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys. Spacecraft may include, but are not limited to, airplanes, rockets, space shuttles, and spacecraft.

[0064] In some embodiments of this application, the electrical device 400 further includes a battery device 200 as described above. That is, the electrical device 400 may employ multiple battery devices 200 connected in series, parallel, or in a mixed configuration, or may be assembled using a single battery device 200. Furthermore, the electrical load 410 is electrically connected to the battery device 200. The battery device 200 is used to store electrical energy, or to provide electrical energy to the electrical load 410, thereby enabling the electrical load 410 to operate normally.

[0065] Alternatively, in some other embodiments of this application, the electrical device 400 further includes a plurality of battery cells 100 as described above. That is, the electrical device 400 uses a plurality of battery cells 100 connected in series, parallel, or in a mixed configuration, and the electrical load 410 is electrically connected to the plurality of battery cells 100. The plurality of battery cells 100 are used to store electrical energy, or the plurality of battery cells 100 are used to provide electrical energy to the electrical load 410, thereby enabling the electrical load 410 to operate normally.

[0066] Among them, the electrical equipment 400 is an electric vehicle, and it is assembled using a battery device 200, such as Figure 8 As shown, the battery device 200 is mounted on the frame 430 of the electric vehicle. The electric vehicle includes the frame 430, a drive motor, and wheels 440. The battery device 200 and the drive motor are both fixedly mounted on the frame 430, and the wheels 440 are rotatably connected to the frame 430. The battery device 200 is electrically connected to the drive motor, and the drive motor is driven by the wheels 440. When the battery device 200 provided in this application supplies power to the drive motor (the drive motor is one of the electrical loads 410 of the electrical equipment 400), the drive motor drives the wheels 440 to rotate, enabling the electric vehicle to drive normally. Furthermore, the electric vehicle includes a control device 420, which is mounted on the frame 430 and electrically connected to the battery device 200. The control device 420 is used to control and monitor the charging and discharging status of the battery device 200. In some electric vehicles, the battery housing of the battery device 200 can be part of the chassis structure of the electric vehicle. For example, a portion of the battery box can be at least part of the floor of the electric vehicle, or a portion of the battery box can be at least part of the crossbeams and longitudinal beams of the electric vehicle.

[0067] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery cell, characterized in that, include: The outer shell has a storage space; An electrode assembly is disposed within the accommodating space. The electrode assembly includes multiple layers of electrode sheets and multiple layers of solid electrolyte layers, which are alternately stacked along a first direction. At least one pressure member is provided between at least one end of the electrode assembly along the first direction and the housing, wherein the pressure member has a zero stiffness characteristic deformation range, and the pressure member applies a compressive force to the electrode assembly within the zero stiffness characteristic deformation range.

2. The battery cell according to claim 1, characterized in that, The pressure applied by the pressure member to the electrode assembly is ΔF1, and the required pre-tightening pressure of the electrode assembly is ΔF2, wherein ΔF2·(1-10%)≤ΔF1≤ΔF2·(1+10%).

3. The battery cell according to claim 1, characterized in that, The outer casing includes a first housing and a second housing, the first housing and the second housing covering each other along the first direction to form the receiving space, the pressure member being disposed between one end of the electrode assembly along the first direction and the first housing, and / or the pressure member being disposed between the other end of the electrode assembly along the first direction and the second housing.

4. The battery cell according to claim 1, characterized in that, Along the first direction, the outline shape of the projection of the electrode sheet is circular, the outline shape of the projection of the solid electrolyte layer is circular, and the projection of the electrode sheet coincides with the projection of the solid electrolyte layer.

5. The battery cell according to claim 3, characterized in that, Along the first direction, the outline of the projection of the outer shell is circular, and the outline projection of the accommodating space coincides with the projection of the electrode sheet.

6. The battery cell according to any one of claims 1-5, characterized in that, The battery cell also includes an adapter, which is disposed between the pressurizing member and the electrode assembly. Along the first direction, one side of the adapter is attached to the end face of the electrode assembly, and the other side of the adapter is connected to the pressurizing member.

7. The battery cell according to claim 6, characterized in that, The pressurizing component includes a disc spring, which is pre-compressed and disposed between the adapter and the housing.

8. The battery cell according to claim 7, characterized in that, The central axis of the disc spring coincides with the central axis of the electrode assembly.

9. The battery cell according to claim 7, characterized in that, Each of the pressurizing components includes multiple disc springs, each disc spring having a recessed space, and the multiple disc springs are stacked in a manner consistent with the recessed direction of the recessed space.

10. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1-9.

11. An electrical appliance, characterized in that, The electrical equipment includes a plurality of battery cells as described in any one of claims 1-9; Alternatively, the electrical device may include the battery device as described in claim 10.

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