Pole piece compression rebound testing device

Abstract

The utility model discloses a pole piece compression rebound testing device. The pole piece compression rebound testing device comprises a first pressing piece, a second pressing piece and a rebound piece, the first pressing piece is provided with a compression groove, and the compression groove is used for arranging a pole piece; the second pressing piece is configured to apply pressure to the pole piece in the compression groove; and the springback piece is configured to at least provide a springback force for the pole piece in the compression groove. Through the mode, the pole piece compression rebound testing device can improve the testing efficiency when the pole piece compression rebound testing device tests the pole piece, and is simple in structure, low in cost and convenient to implement.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a pole piece compression rebound testing device. Background Art

[0002] With the development of battery technology, batteries are used in more and more fields and gradually replace traditional petrochemical energy in areas such as automotive power. Batteries can store chemical energy and controllably convert chemical energy into electrical energy. In recyclable batteries, active materials can be activated by charging after discharge for continued use.

[0003] In lithium battery manufacturing, "pole compression modulus" and "pole rebound data" are key parameters that describe the mechanical behavior of the battery's pole during mechanical compression. In the battery manufacturing process, reasonable control of the pole compression modulus and pole rebound data of the pole is of great significance for maintaining the stability of the battery structure, improving the cycle life and battery consistency.

[0004] In the prior art, in order to measure the compression modulus and springback data of the pole piece, a complex measuring device is usually required. The measurement process has high experimental requirements. It is difficult to meet such test conditions at the actual production site of the product, and the test efficiency is low. Utility Model Content

[0005] In view of the above problems, the present application provides a pole piece compression rebound test device to improve the test efficiency of the pole piece compression rebound test device when testing the pole piece, and the structure is simple, the cost is low, and it is easy to implement.

[0006] In the first aspect, the present application provides a pole piece compression rebound test device, which includes a first pressing piece, a second pressing piece, and a resilient piece. The first pressing piece is provided with a compression groove, and the compression groove is used to set the pole piece; the second pressing piece is configured to apply pressure to the pole piece located in the compression groove; the resilient piece is configured to at least provide a rebound force to the pole piece in the compression groove. In this way, in a compressed state, the second pressing piece can be used to apply pressure to the pole piece located in the compression groove, so that the pole piece is compressed, and then the compression modulus of the pole piece can be obtained according to the thickness of the pole piece before and after compression; further, in a rebound state, the resilient piece can be used to eject the pole piece in the compression groove out of the compression groove, thereby improving the convenience of taking out the pole piece, and thus improving the test efficiency of the pole piece compression rebound test device when testing the pole piece; further, this design has a simple structure, low cost, and is easy to implement.

[0007] In some embodiments, a rebound hole is provided on the bottom wall of the compression groove, and in the rebound state, at least part of the rebound member extends from the rebound hole into the compression groove to provide a rebound force to the pole piece in the compression groove. This method has a simple structure and can quickly eject the pole piece in the compression groove in the above-mentioned rebound state.

[0008] In some embodiments, the resilient member includes a resilient portion and a resilient base, the resilient portion is disposed on a side of the resilient base close to the first pressure member, and the resilient portion is configured to at least partially extend from the resilient hole into the compression groove. This method can improve the convenience of operation, and facilitates applying force to the resilient base to push at least a portion of the resilient portion to extend from the resilient hole into the compression groove.

[0009] In some embodiments, in the rebound state, along the depth direction of the compression groove, the projection of the rebound base covers the projection of the rebound portion. This method can make the size of the rebound base larger than the size of the rebound portion in the vertical plane in the depth direction, which can further improve the convenience of operation and the convenience and efficiency of removing the pole piece from the compression groove.

[0010] In some embodiments, the compression groove is a cylindrical groove. This arrangement can make the test environment closer to the actual working environment when the pole piece is arranged in the housing of the battery cell, and can further improve the reliability of the test results.

[0011] In some embodiments, the compression groove is a cylindrical groove, the rebound hole is a circular hole, the rebound portion is a cylindrical rebound column, and the rebound base is a disc-shaped rebound base; the compression groove, the rebound hole, the rebound portion, and the rebound base are coaxially arranged. This arrangement can further improve the efficiency and operational convenience of ejecting the pole piece from the compression groove, improve the test efficiency, and reduce the risk of the pole piece being offset or twisted during the ejection process.

[0012] In some embodiments, the outer surface of the side wall of the compression groove is provided with a plurality of scale marks arranged along the depth direction of the compression groove. This arrangement facilitates visual monitoring of the displacement of the pole piece during compression by manual or mechanical means, which can further improve the accuracy and convenience of the test, and this structure is simple, does not require complex structures such as sensors, and is more suitable for actual production sites.

[0013] In some embodiments, a first opening is provided on the side wall, which is connected to the compression groove and extends in the depth direction, and a plurality of scale marks are arranged on the outer surface of the hole wall of the first opening along the extension direction of the first opening. This arrangement not only improves the visibility of the scale marks, but also allows the tester to directly observe the compression of the pole piece through the first opening, and obtain the vertical deformation data of the pole piece according to the scale marks, so as to facilitate the calculation of the compression modulus of the pole piece, and can enhance the real-time and accuracy of the test.

[0014] In some embodiments, the first opening extends from the notch of the compression groove to the bottom of the compression groove along the depth direction; and a plurality of scale marks are arranged from the notch of the compression groove to the bottom of the compression groove along the depth direction. This arrangement can increase the observable range and provide continuous data monitoring, making the test results more stable and reliable.

[0015] In some embodiments, in a vertical plane in the depth direction of the compression groove, the geometric shape and size of the cross section of the pole piece are the same as the geometric shape and size of the compression groove, so that the edge of the pole piece disposed in the compression groove abuts against the inner surface of the side wall of the compression groove. This arrangement can use the inner surface of the side wall of the compression groove to apply a lateral force to the pole piece in a compressed state, so that the test process is closer to the actual environment of the pole piece in the housing of the battery cell, and the reliability of the test results is improved.

[0016] In some embodiments, the second pressing member is configured to at least partially press into the compression groove to apply pressure to the pole piece; in the compressed state, the projection of the abutment surface of the second pressing member and the pole piece in the vertical plane in the depth direction completely overlaps with the projection of the cross section of the pole piece in the vertical plane in the depth direction. In this way, the pressure applied by the second pressing member to the pole piece is more evenly distributed, thereby improving the consistency and accuracy of the compression of the pole piece.

[0017] In some embodiments, the second pressing member includes a pressing portion and a pressing base, the pressing portion is arranged on the pressing base, and the pressing portion is configured to at least partially press into the compression groove to apply pressure to the pole piece; in the compressed state, along the depth direction of the compression groove, the projection of the pressing base covers the projection of the pressing portion. This arrangement can increase the force-bearing area of ​​the second pressing member by using the pressing base, improve the operating efficiency, and improve the uniformity of the force applied to the pressing portion, thereby making the force applied by the pressing portion to the pole piece more evenly distributed, thereby improving the consistency and accuracy of the pole piece compression.

[0018] In some embodiments, the pole piece compression rebound test device also includes a first driving member, which is configured to drive the second pressing member to move toward the first pressing member in a compressed state, so that the second pressing member is at least partially pressed into the compression groove through the notch of the compression groove. This arrangement can improve the degree of automation of the test and improve the convenience of operation. In an application scenario, the first driving member is a press, which can drive the second pressing member to move toward the first pressing member, so that the second pressing member is at least partially pressed into the compression groove through the notch of the compression groove; in an application scenario, the first driving member can also drive the rebound member to move, so that the rebound member provides a rebound force to the pole piece in the compression groove.

[0019] The present application provides a pole piece compression rebound test device, which includes a first pressing piece, a second pressing piece, and a resilient piece. The first pressing piece is provided with a compression groove, and the compression groove is used to set the pole piece; the second pressing piece is configured to apply pressure to the pole piece located in the compression groove; the resilient piece is configured to at least provide a resilient force to the pole piece in the compression groove. In this way, in a compressed state, the second pressing piece can be used to apply pressure to the pole piece located in the compression groove, so that the pole piece is compressed, and then the compression modulus of the pole piece can be obtained according to the thickness of the pole piece before and after compression; further, in a rebound state, the resilient piece can be used to eject the pole piece in the compression groove out of the compression groove, thereby improving the convenience of taking out the pole piece, and thus improving the test efficiency of the pole piece compression rebound test device when testing the pole piece; further, this design structure is simple, low cost, and easy to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0021] Figure 1 is a schematic structural diagram of a vehicle according to one or more embodiments;

[0022] Figure 2 is a schematic diagram of an exploded structure of a battery according to one or more embodiments;

[0023] Figure 3 is a schematic structural diagram of a battery according to one or more embodiments;

[0024] Figure 4 A schematic diagram of the structure of a pole piece compression rebound test device according to one or more embodiments;

[0025] Figure 5 for Figure 4 a schematic side view of the illustrated embodiment;

[0026] Figure 6 is a schematic structural diagram of a first pressing member according to one or more embodiments;

[0027] Figure 7 Schematic diagram of the structure of a first pressing member and a pole piece according to one or more embodiments.

[0028] The reference numerals in the specific implementation manner are as follows:

[0029] 1000a vehicles;

[0030] 100a battery; 200a controller; 300a motor;

[0031] 10a battery box; 11a first part; 12a second part;

[0032] 1 battery cell; 100 housing; 110 shell; 120 end cover;

[0033] 500 electrode assembly; 501 pole ear;

[0034] 21 first pressing member; 210 compression groove; 211 bottom wall of the compression groove; 212 rebound hole; 213 side wall of the compression groove; 214 first opening;

[0035] 22 second pressing member; 221 pressing portion; 222 pressing base;

[0036] 23 rebound member; 231 rebound portion; 232 rebound base;

[0037] 30 pole pieces; 40 scale markings;

[0038] y depth direction. DETAILED DESCRIPTION

[0039] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0041] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0042] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0043] In the description of the embodiments of the present application, the orientations or positional relationships indicated by technical terms such as "center", "bottom", "inside" and "outside" are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present application and simplifying the description. They do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the embodiments of the present application.

[0044] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0045] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0046] With the development of battery technology, batteries are used in more and more fields and gradually replace traditional petrochemical energy in areas such as automotive power. Batteries can store chemical energy and controllably convert chemical energy into electrical energy. In recyclable batteries, active materials can be activated by charging after discharge for continued use.

[0047] The energy density and weight reduction requirements of batteries are getting higher and higher. Through multifunctional integrated design as much as possible, the same structure can play dual or multiple functions. Integrated design can also achieve the purpose of weight reduction. In related technologies, the battery box is composed of a bottom plate, a water-cooling plate, a support beam and a cover plate. The water-cooling plate is set on the bottom plate, and the cover plate is sealed and locked with the support beam through fasteners and seals to seal the accommodation space surrounded by the bottom plate and the support beam. This box structure has many components, which is not conducive to battery weight reduction, process simplification and miniaturization (or energy density improvement).

[0048] In lithium battery manufacturing, "pole piece compression modulus" and "pole piece rebound data" are key parameters that describe the mechanical behavior of the battery's pole piece during mechanical compression. They describe the pole piece's ability to resist deformation during compression and its tendency to return to its original shape after pressure is released, respectively. These two concepts have an important impact on the morphological control of the pole piece and the performance stability of the finished battery during battery manufacturing. The pole piece compression modulus is a parameter that measures the deformation resistance of the pole piece under compression, and represents the pole piece's resistance to compression deformation. It is similar to the elastic modulus in material mechanics and is used to evaluate the "rigidity" or "hardness" of the pole piece. Pole piece rebound refers to the phenomenon that after the pole piece is compressed, when the external pressure is released, the pole piece partially returns to its original thickness. Pole piece rebound is actually the elastic recovery behavior of the pole piece. In the battery manufacturing process, reasonable control of the pole piece compression modulus and pole piece rebound data of the pole piece is of great significance for maintaining the stability of the battery structure, improving the cycle life and battery consistency.

[0049] In the prior art, in order to measure the compression modulus and springback data of the pole piece, a complex measuring device is usually required. The measurement process has high experimental requirements. It is difficult to meet such test conditions at the actual production site of the product, and the test efficiency is low.

[0050] Based on the above considerations, the present application provides a pole piece compression rebound test device. Among them, the pole piece compression rebound test device includes a first pressing piece, a second pressing piece, and a resilient piece. The first pressing piece is provided with a compression groove, and the compression groove is used to set the pole piece; the second pressing piece is configured to apply pressure to the pole piece located in the compression groove; the resilient piece is configured to at least provide a rebound force to the pole piece in the compression groove. In this way, in the compressed state, the second pressing piece can be used to apply pressure to the pole piece located in the compression groove, so that the pole piece is compressed, and then the compression modulus of the pole piece can be obtained according to the thickness of the pole piece before and after compression; further, in the rebound state, the resilient piece can be used to pop the pole piece in the compression groove out of the compression groove, thereby improving the convenience of removing the pole piece, and thus can improve the test efficiency of the pole piece compression rebound test device when testing the pole piece; further, this design structure is simple and easy to implement.

[0051] The pole piece compression rebound test device disclosed in the embodiment of the present application can be used to measure the "pole piece compression modulus" and "pole piece rebound data" of the pole piece (such as the positive pole piece or the negative pole piece) of the battery. Among them, the pole piece can be used in an electrical device that uses a battery as a power source or various energy storage systems that use a battery as an energy storage element. The electrical device can be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, and the like. Among them, the electric toys may include fixed or mobile electric toys, for example, game consoles, electric car toys, electric ship toys, electric airplane toys, and the like, and the spacecraft may include airplanes, rockets, space shuttles, spacecrafts, and the like.

[0052] For the convenience of description, the following embodiments are described by taking a vehicle 1000a as an example of an electrical device in an embodiment of the present application.

[0053] Please refer to Figure 1 , the vehicle 1000a can be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100a is arranged inside the vehicle 1000a, and the battery 100a can be arranged at the bottom, head or tail of the vehicle 1000a. The battery 100a can be used to power the vehicle 1000a, for example, the battery 100a can be used as an operating power source for the vehicle 1000a. The vehicle 1000a may also include a controller 200a and a motor 300a, and the controller 200a is used to control the battery 100a to power the motor 300a, for example, for the starting, navigation and driving power requirements of the vehicle 1000a.

[0054] In some embodiments of the present application, the battery 100a can not only serve as the operating power source of the vehicle 1000a, but also serve as the driving power source of the vehicle 1000a, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000a.

[0055] In some embodiments, the battery 100a may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0056] The battery 100 a mentioned in the embodiment of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.

[0057] In the embodiment of the present application, the battery cell may be a secondary battery, which refers to a battery cell that can be continuously used by activating the active material by charging after the battery cell is discharged. The battery cell may also be a primary battery.

[0058] Battery cells include but are not limited to lithium-ion battery cells, sodium-ion battery cells, sodium-lithium-ion battery cells, lithium metal battery cells, sodium metal battery cells, lithium-sulfur battery cells, magnesium-ion battery cells, nickel-hydrogen battery cells, nickel-cadmium battery cells, lead-acid battery cells, etc.

[0059] In some embodiments, the battery 100a may be a battery module. When there are multiple battery cells 1, the multiple battery cells 1 are arranged and fixed to form a battery module.

[0060] In some embodiments, please refer to Figure 2 The battery 100a may be a battery pack, which includes a battery case 10a and a battery cell 1, wherein the battery cell 1 or a battery module is accommodated in the battery case 10a.

[0061] In some embodiments, the battery box 10a can be used as part of the chassis structure of the vehicle 1000a. For example, a portion of the battery box 10a can become at least a portion of the floor of the vehicle 1000a, or a portion of the battery box 10a can become at least a portion of the cross beam and longitudinal beam of the vehicle 1000a.

[0062] Please refer to Figure 2 The battery 100a includes a battery case 10a and a battery cell 1, and the battery cell 1 is contained in the battery case 10a. The battery case 10a is used to provide a storage space for the battery cell 1, and the battery case 10a can adopt a variety of structures. In some embodiments, the battery case 10a may include a first part 11a and a second part 12a, and the first part 11a and the second part 12a cover each other, and the first part 11a and the second part 12a jointly define a storage space for accommodating the battery cell 1. The second part 12a may be a hollow structure with one end open, and the first part 11a may be a plate-like structure, and the first part 11a covers the open side of the second part 12a, so that the first part 11a and the second part 12a jointly define a storage space; the first part 11a and the second part 12a may also be hollow structures with one side open, and the open side of the first part 11a covers the open side of the second part 12a. Of course, the battery case 10a formed by the first part 11a and the second part 12a can be in various shapes, such as a cylinder, a cuboid, etc.

[0063] In the battery 100a, there can be multiple battery cells 1, and the multiple battery cells 1 can be connected in series, in parallel, or in a mixed connection. The mixed connection means that the multiple battery cells 1 are both connected in series and in parallel. The multiple battery cells 1 can be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by the multiple battery cells 1 is accommodated in the battery box 10a; of course, the battery 100a can also be a battery module formed by connecting multiple battery cells 1 in series, in parallel, or in a mixed connection, and then the multiple battery modules are connected in series, in parallel, or in a mixed connection to form a whole, and accommodated in the battery box 10a. The battery 100a may also include other structures. For example, the battery 100a may also include a converging component for realizing electrical connection between the multiple battery cells 1.

[0064] Please refer to Figure 3 The battery cell 1 refers to the smallest unit that constitutes the battery. In this embodiment, a cylindrical battery cell 1 is taken as an example for description. Figure 3 and Figure 4 As shown, the battery cell 1 includes a housing 100 , an electrode assembly 500 and other functional components.

[0065] In some embodiments, the housing 100 is used to encapsulate the electrode assembly 500 and electrolyte components. The housing 100 may be a steel housing, an aluminum housing, a plastic housing (such as polypropylene), a composite metal housing (such as a copper-aluminum composite housing), or an aluminum-plastic film.

[0066] The housing 100 may include an end cap 120 and a shell 110. The end cap 120 refers to a component that covers the opening of the shell 110 to isolate the internal environment of the battery cell 1 from the external environment. Without limitation, the shape of the end cap 120 can be adapted to the shape of the shell 110 to match the shell 110. Optionally, the end cap 120 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 120 is not easily deformed when squeezed and collided, so that the battery cell 1 can have a higher structural strength and the safety performance can also be improved.

[0067] In some embodiments, the end cap 120 may also be provided with a pressure relief mechanism for releasing the internal pressure when the internal pressure or temperature of the battery cell 1 reaches a threshold value. The material of the end cap 120 may also be various, for example, including but not limited to copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. In some embodiments, an insulating component may also be provided on the inner side of the end cap 120, and the insulating component may be used to isolate the electrical connection components in the housing 110 from the end cap 120 to reduce the risk of short circuit. Exemplarily, the insulating component may be plastic, rubber, etc.

[0068] The shell 110 is a component used to cooperate with the end cap 120 to form the internal environment of the battery cell 1, wherein the formed internal environment can be used to accommodate the electrode assembly 500, the electrolyte and other components. The shell 110 and the end cap 120 can be independent components. For example, an opening is set on the shell 110, and the end cap 120 can cover the opening of the shell 110 to form the internal environment of the battery cell 1. In addition, the end cap 120 and the shell 110 can also be integrated. For example, the end cap 120 and the shell 110 can form a common connection surface before other components are put into the shell, and when the interior of the shell 110 needs to be encapsulated, the end cap 120 covers the shell 110. The shell 110 can be of various shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, a hexagonal prism, etc. Specifically, the shape of the shell 110 can be determined according to the specific shape and size of the electrode assembly 500. The material of the shell 110 can be various, for example, including but not limited to copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0069] The electrode assembly 500 is a component where electrochemical reactions occur in the battery cell 1. One or more electrode assemblies 500 may be contained in the housing 110.

[0070] In some embodiments, the electrode assembly 500 includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are inserted and removed between the positive electrode and the negative electrode. The separator is arranged between the positive electrode and the negative electrode to prevent the positive and negative electrodes from short-circuiting, while allowing the active ions to pass through.

[0071] In some embodiments, the positive electrode may be a positive electrode sheet, and the positive electrode sheet may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0072] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material is disposed on either or both of the two facing surfaces of the positive electrode current collector.

[0073] As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum or stainless steel treated with silver, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. may be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0074] As an example, the positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. However, the present application is not limited to these materials, and other traditional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. Among them, examples of lithium-containing phosphates may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon. Examples of lithium transition metal oxides may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi1 / 3Co1 / 3Mn1 / 3O2 (also referred to as NCM333), LiNi0.5Co0.2Mn0.3O2 (also referred to as NCM523), LiNi0.5Co0.25Mn0.25O2 (also referred to as NCM211), LiNi0.6Co0.2Mn0.2O2 (also referred to as NCM622), LiNi0.8Co0.1Mn0.1O2 (also referred to as NCM811), lithium nickel cobalt aluminum oxide (such as LiNi0.85Co0.15Al0.05O2) and its modified compounds.

[0075] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0076] As an example, the negative electrode current collector may be a metal foil, a foamed metal or a composite current collector. For example, as the metal foil, aluminum or stainless steel treated with silver, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. may be used. The foamed metal may be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. The composite current collector may include a polymer material base and a metal layer. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0077] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0078] As an example, the negative electrode current collector has two surfaces facing each other in its thickness direction, and the negative electrode active material is disposed on either or both of the two facing surfaces of the negative electrode current collector.

[0079] As an example, the negative electrode active material may adopt the negative electrode active material for battery cells known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0080] In some embodiments, the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.

[0081] In some embodiments, the electrode assembly 500 further includes a separator disposed between the positive electrode and the negative electrode.

[0082] In some embodiments, the separator is a separator. The present application has no particular limitation on the type of separator, and any known separator with a porous structure having good chemical stability and mechanical stability can be selected.

[0083] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without special restrictions. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without special restrictions. The separator can be a separate component located between the positive and negative electrodes, or it can be attached to the surface of the positive and negative electrodes.

[0084] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transmit ions and isolate the positive and negative electrodes.

[0085] In some embodiments, the battery cell further includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The present application has no specific restrictions on the type of electrolyte, which can be selected according to needs. The electrolyte can be liquid, gel or solid.

[0086] The liquid electrolyte includes an electrolyte salt and a solvent.

[0087] In some embodiments, the electrolyte salt can be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium dioxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.

[0088] In some embodiments, the solvent can be selected from at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, cyclopentane, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone. The solvent can also be selected from ether solvents. Ether solvents can include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyltetrahydrofuran, diphenyl ether and crown ether.

[0089] Among them, the gel electrolyte includes a skeleton network with a polymer as the electrolyte, combined with an ionic liquid-lithium salt.

[0090] Among them, solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0091] As an example, the polymer solid electrolyte may be polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, a single ion polymer, polyionic liquid-lithium salt, cellulose, and the like.

[0092] As an example, the inorganic solid electrolyte can be an oxide solid electrolyte (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON film), a sulfide solid electrolyte (crystalline lithium superion conductor (lithium germanium phosphosulfide, silver germanium sulfide), amorphous sulfide) and one or more of a halide solid electrolyte, a nitride solid electrolyte and a hydride solid electrolyte.

[0093] As an example, the composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0094] In some embodiments, the electrode assembly 500 is a wound structure. The positive electrode sheet and the negative electrode sheet are wound into a wound structure.

[0095] In some embodiments, the electrode assembly 500 is provided with a tab 501, which can lead current from the electrode assembly 500. The tab includes a positive tab and a negative tab. The positive tab and the negative tab can be located at one end of the main body or at both ends of the main body. During the charge and discharge process of the battery 100a, the positive active material and the negative active material react with the electrolyte.

[0096] In some embodiments, Figures 4 to 7 As shown, the pole piece compression rebound test device includes a first pressing piece 21, a second pressing piece 22, and a rebound piece 23. The first pressing piece 21 is provided with a compression groove 210, and the compression groove 210 is used to set the pole piece 30; the second pressing piece 22 is configured to apply pressure to the pole piece 30 located in the compression groove 210; the rebound piece 23 is configured to at least provide a rebound force to the pole piece 30 in the compression groove 210.

[0097] Among them, the first pressing member 21 is used to set the compression groove 210, the second pressing member 22 is used to apply pressure to the pole piece 30 in the compression groove 210, and the rebound member 23 is used to pop out the pole piece 30 in the compression groove 210, so as to facilitate the removal of the pole piece 30. In the compressed state, a specific pressure is applied to the pole piece 30 in the compression groove 210 to compress it, and the pole piece compression modulus can be obtained according to the pressure value, the vertical deformation data of the compressed pole piece 30, etc. In the compression release state, the pressure applied to the pole piece 30 is removed, and the rebound of the pole piece 30 within the preset time is observed, and the pole piece rebound data can be obtained. After the test is completed, in the rebound state, the pole piece 30 in the compression groove 210 needs to be taken out, and the rebound member 23 can be used to pop the pole piece 30 in the compression groove 210 out of the compression groove 210.

[0098] In some embodiments, a machine press (such as a press) or a heavy object with a fixed weight can be used to press the second pressing member 22 along the depth direction y of the compression groove 210, so that the second pressing member 22 applies a fixed load to the pole piece 30 in the compression groove 210, which can improve the accuracy and consistency of the test.

[0099] In one application scenario, the pole piece 30 to be tested is placed in the compression groove 210, and the second pressing piece 22 is used to extend through the notch of the compression groove 210 into the compression groove 210 to apply pressure to the pole piece 30. The pole piece 30 is compressed under the extrusion of the bottom wall 211 of the compression groove, the side wall 213 of the compression groove and the second pressing piece 22. Among them, the pressure applied to the pole piece 30 by the second pressing piece 22 can be a fixed value, and the specific pressure value can be determined according to the test requirements. After completing the test of the pole piece compression modulus, the pressure applied by the second pressing piece 22 on the pole piece 30 is removed, and the pole piece rebound data can be obtained according to the rebound amount of the pole piece 30 after a preset time. After completing the test of the pole piece compression modulus and the pole piece rebound data, the rebound piece 23 can be used to provide a rebound force to the pole piece 30 in the compression groove 210, so that the pole piece 30 can be ejected from the compression groove 210, that is, it is easy to take the pole piece 30 out of the compression groove 210. It should be noted that the arrangement of the resilient member 23 is not limited, and details may be found in the specific implementation manner described below, which will not be described in detail here.

[0100] In this way, in the compression state, the second pressure piece 22 can be used to apply pressure to the pole piece 30 located in the compression groove 210, so that the pole piece 30 is compressed, and then the compression modulus of the pole piece 30 can be obtained according to the thickness of the pole piece 30 before and after compression; further, in the rebound state, the pole piece 30 in the compression groove 210 can be ejected out of the compression groove 210 by using the rebound piece 23, so as to improve the convenience of taking out the pole piece 30, and thus can improve the test efficiency of the pole piece 30 compression rebound test device when testing the pole piece 30; further, this design has a simple structure, low cost, is easy to implement, and is more suitable for actual production sites.

[0101] In some embodiments, see Figure 6 The bottom wall 211 of the compression groove is provided with a rebound hole 212 . In the rebound state, at least a portion of the rebound member 23 extends from the rebound hole 212 into the compression groove 210 , providing a rebound force to the pole piece 30 in the compression groove 210 .

[0102] This method has a simple structure and can quickly eject the pole piece 30 in the compression groove 210 in the above-mentioned rebound state. By providing the rebound hole 212, the rebound member 23 is used to pass through the rebound hole 212 to apply force to the pole piece 30 in the compression groove 210, so that the pole piece 30 can be ejected from the compression groove 210 more conveniently and quickly.

[0103] The number, size and shape of the rebound holes 212 are not limited. For example, the rebound holes 212 can be circular holes, and the rebound member 23 has a cylindrical structure that can extend into the rebound holes 212. Another example is that the rebound holes 212 are square holes.

[0104] In an application scenario, in the compressed state, at least a portion of the resilient member 23 may be disposed in the rebound hole 212 but not extended into the compression groove 210. This enables the abutting surface of the part of the resilient member 23 disposed in the rebound hole 212 facing the compression groove 210 to be in the same plane as the bottom wall 211 of the compression groove, so the part of the resilient member 23 in the rebound hole 212 can provide a compressive force for the compression pole piece 30 together with the bottom wall 211 of the compression groove and the second compression member 22.

[0105] In some embodiments, the second pressing member 22 applies pressure toward the pole piece 30 in the compression groove 210 along the depth direction y of the compression groove 210 .

[0106] This method can improve the ease of measurement and make it easier to obtain the vertical deformation data of the pole piece 30 under a preset pressure value, thereby making it easier to obtain the pole piece compression modulus of the pole piece 30 .

[0107] In some embodiments, the extension direction of the rebound hole 212 is the same as the depth direction y of the compression groove 210 .

[0108] This approach allows at least a portion of the rebound member 23 to extend into the compression groove 210 along the depth direction y of the compression groove 210 , which can simplify the structural design, reduce the extension path of the rebound member 23 in the rebound hole 212 , and apply the rebound force to the pole piece 30 more quickly.

[0109] In some embodiments, the abutting surface between the resilient member 23 and the pole piece 30 is perpendicular to the depth direction y of the compression groove 210 .

[0110] This approach enables the rebound force applied by the rebound member 23 to the pole piece 30 to be along the depth direction y of the compression groove 210 , so as to facilitate faster ejection of the pole piece 30 from the compression groove 210 and improve the efficiency of removing the pole piece 30 .

[0111] In some embodiments, Figure 4 , Figure 5 As shown, the rebound member 23 includes a rebound portion 231 and a rebound base 232 . The rebound portion 231 is disposed on a side of the rebound base 232 close to the first pressing member 21 . The rebound portion 231 is configured to at least partially extend from the rebound hole 212 into the compression groove 210 .

[0112] This method can improve the convenience of operation, and it is convenient to apply force to the rebound base 232 to push at least part of the rebound portion 231 to extend from the rebound hole 212 to the compression groove 210. In the above-mentioned rebound state, the rebound portion 231 is arranged on the side of the rebound base 232 close to the first pressing piece 21, and at least part of the rebound portion 231 can extend into the rebound hole 212 and extend into the compression groove 210, so as to apply force to the pole piece 30 in the compression groove 210, so that the pole piece 30 is ejected from the compression groove 210. A force can be applied to the side of the rebound base 232 away from the first pressing piece 21 to push the rebound portion 231 to move toward the first pressing piece 21, so as to facilitate pushing at least part of the rebound portion 231 into the compression groove 210, for example, the rebound portion 231 can be pushed into the compression groove 210.

[0113] In some embodiments, in the rebound state, along the depth direction y of the compression groove 210 , the projection of the rebound base 232 covers the projection of the rebound portion 231 .

[0114] This method can make the size of the rebound base 232 larger than the size of the rebound part 231 in the vertical plane of the depth direction y, which can further improve the convenience of operation and improve the convenience and efficiency of taking the pole piece 30 out of the compression groove 210. In the rebound state, the pole piece 30 that has completed the test needs to be taken out of the compression groove 210. Along the depth direction y of the compression groove 210, the projection of the rebound base 232 covers the projection of the rebound part 231. For example, in an application scenario, the rebound base 232 is a disc structure, and the rebound part 231 is a rebound column arranged on the rebound base 232 and extending toward the first pressing piece 21 along the depth direction y of the compression groove 210. Since the contact area of ​​the disc structure is larger, when applying force to the rebound base 232, it is easier to apply a stable and uniform force, so that the rebound column can pass through the rebound hole 212 more quickly and stably and enter the compression groove 210.

[0115] In some embodiments (not shown), a gasket movable along the depth direction of the compression groove is provided on the inner surface of the bottom wall of the compression groove, and the projection of the abutting surface of the gasket abutting against the pole piece in a vertical plane in the depth direction of the compression groove completely overlaps with the projection of the cross section of the pole piece in the vertical plane.

[0116] This method can further improve the efficiency of ejecting the pole piece out of the compression groove and reduce the risk of damage to the pole piece. Among them, the cross section of the pole piece refers to the cross section in the vertical plane in the depth direction of the compression groove. The projection of the abutment surface on the gasket that abuts the pole piece completely coincides with the projection of the cross section of the pole piece, which can increase the force area between the gasket and the pole piece. In the rebound state, at least part of the rebound member extends from the rebound hole into the compression groove, and the rebound member exerts force on the gasket, and the gasket transmits the rebound force to the pole piece, thereby being able to eject the pole piece out of the compression groove. Therefore, the design of the gasket can increase the force area of ​​the pole piece when a rebound force is applied to the pole piece, improve the ejection efficiency, and reduce the risk of damage to the pole piece.

[0117] In the compressed state, the gasket can also increase the extrusion pressure at the rebound hole in the compression groove, so that the pole piece is compressed under the action of the gasket, the second pressing piece, the bottom wall and the side wall of the compression groove.

[0118] In some embodiments, in a vertical plane in the depth direction y of the compression groove 210, the geometric shape and size of the cross section of the pole piece 30 are the same as the geometric shape and size of the compression groove 210, so that the edge of the pole piece 30 arranged in the compression groove 210 abuts against the inner surface of the side wall 213 of the compression groove.

[0119] This arrangement can use the inner surface of the side wall 213 of the compression groove to apply a lateral limiting force to the pole piece 30 in a compressed state, so that the test process is closer to the actual environment of the pole piece 30 in the shell of the battery cell 1, and the reliability of the test results is improved. Specifically, in the prior art, when testing the pole piece 30, there is usually no binding force on both sides of the pole piece 30 during the compression process of the pole piece 30, which is greatly different from the actual situation when the pole piece 30 is in the battery cell, and the accuracy and reliability of the test results are poor. In this embodiment, the geometric shape and size of the cross section of the pole piece 30 are arranged to be the same as the geometric shape and size of the compression groove 210, so that the edge of the pole piece 30 arranged in the compression groove 210 can abut against the inner surface of the side wall 213 of the compression groove. In the compressed state, the inner surface of the side wall 213 of the compression groove can provide a lateral limiting force on the pole piece 30, thereby improving the reliability of the test results.

[0120] In some embodiments, the compression groove 210 is a cylindrical groove.

[0121] This arrangement of the present embodiment can make the test environment closer to the actual working environment when the pole piece 30 is set in the shell of the battery cell 1, and can further improve the reliability of the test results. Specifically, the pole piece 30 is usually wound into a winding structure to form an electrode assembly 500. The electrode assembly 500 is set in the shell 100 and will be squeezed in multiple directions. The compression groove 210 is set as a cylindrical groove, and the pole piece 30 to be tested is further set as a round piece with a size matching the inner diameter of the compression groove. In the compressed state, the side wall 213 of the compression groove can form a lateral limit force on the pole piece 30, which can be closer to the actual situation that the pole piece 30 will encounter a large lateral limit force when it is set in the battery 100a and compressed, thereby improving the accuracy and reliability of the test results.

[0122] In other embodiments, the compression groove 210 and the corresponding electrode piece 30 to be tested may be arranged in other shapes, such as square, rectangular, elliptical, etc., which will not be described in detail.

[0123] In some embodiments, the rebound hole 212 is a circular hole, the rebound portion 231 is a cylindrical rebound column, and the rebound base 232 is a disc-shaped rebound base.

[0124] This arrangement has a simple structure, is easy to produce and process, and can reduce costs.

[0125] In some embodiments, the compression groove 210 is a cylindrical groove, the rebound hole 212 is a circular hole, the rebound portion 231 is a cylindrical rebound column, and the rebound base 232 is a disc-shaped rebound base; the compression groove 210, the rebound hole 212, the rebound portion 231, and the rebound base 232 are coaxially arranged.

[0126] This arrangement can further improve the efficiency and operational convenience of ejecting the pole piece 30 from the compression groove 210, improve the test efficiency, and reduce the risk of the pole piece 30 being offset or twisted during the ejection process. Specifically, the coaxial arrangement can improve the ejection effect of the pole piece 30. In the rebound state, the rebound base 232 is coaxial with the rebound portion 231, and the force applied to the rebound base 232 can be better transmitted to the rebound portion 231; the rebound portion 231 is coaxial with the rebound hole 212 and the compression groove 210, so that the rebound force provided by the rebound portion 231 can act evenly on the pole piece 30, which can reduce the risk of the pole piece 30 being offset or twisted during the ejection process.

[0127] In some embodiments, in a vertical plane in the depth direction y of the compression groove 210, the outer diameter of the cross section of the cylindrical rebound column is equal to the inner diameter of the rebound hole 212; in other embodiments, in a vertical plane in the depth direction y of the compression groove 210, the outer diameter of the cross section of the cylindrical rebound column is slightly smaller than the inner diameter of the rebound hole 212, for example, the outer diameter of the cross section of the cylindrical rebound column is 1 mm smaller than the inner diameter of the rebound hole 212. This arrangement facilitates the rebound column to slide easily in the rebound hole 212, reduces friction, and improves the ejection efficiency of the pole piece 30.

[0128] In other embodiments, the shapes of the compression groove 210, the rebound hole 212, the rebound portion 231, and the rebound base 232 may not be limited. For example, the compression groove 210, the rebound hole 212, the rebound portion 231, and the rebound base 232 may be set to other shapes, and the compression groove 210, the rebound hole 212, the rebound portion 231, and the rebound base 232 may be coaxially arranged.

[0129] In some embodiments, see Figure 4 The outer surface of the side wall 213 of the compression groove is provided with a plurality of scale marks 40 arranged along the depth direction y of the compression groove 210 .

[0130] This arrangement facilitates visual monitoring of the displacement of the pole piece 30 during compression by manual or mechanical means, which can further improve the accuracy and convenience of the test. In addition, this structure is simple and does not require complex structures such as sensors, making it more suitable for actual production sites.

[0131] In one application scenario, the compression groove 210 is a transparent compression groove 210, and the changes of the pole piece 30 during the compression process can be visually observed through the scale mark 40, so as to accurately grasp the test data. In another application scenario, a first opening 214 can also be set on the side wall 213 of the compression groove to observe the state of the pole piece 30 during the compression process, providing a more intuitive monitoring method for the tester.

[0132] In some embodiments, see Figure 4 A first opening 214 communicating with the compression groove 210 and extending along the depth direction y is provided on the side wall, and a plurality of scale marks 40 are arranged on the outer surface of the hole wall of the first opening 214 along the extension direction of the first opening 214 .

[0133] This setting can not only improve the visibility of the scale mark 40, but also allow the tester to directly observe the compression of the pole piece 30 through the first opening 214, and can obtain the vertical deformation data of the pole piece 30 according to the scale mark 40, so as to facilitate the calculation of the compression modulus of the pole piece 30, and can enhance the real-time and accuracy of the test. Specifically, the first opening 214 extends along the depth direction y of the compression groove 210, and a plurality of scale marks 40 are arranged on the outer surface of the hole wall of the first opening 214, so that the compression of the pole piece 30 observed at the first opening 214 can be manually read according to the scale mark 40. Furthermore, the first opening 214 extends along the depth direction y of the compression groove 210, so that the vertical deformation data of the pole piece 30 can be observed more intuitively.

[0134] In some embodiments, the first opening 214 extends from the slot opening of the compression slot 210 to the bottom of the compression slot 210 along the depth direction y; and a plurality of scale marks 40 are arranged from the slot opening of the compression slot 210 to the bottom of the compression slot 210 along the depth direction y.

[0135] This setting can increase the observable range and provide continuous data monitoring, making the test results more stable and reliable.

[0136] In some embodiments (not shown), a first opening 214 is provided on the side wall 213 of the compression groove, which is connected to the compression groove 210 and extends along the depth direction y of the compression groove 210; a gasket is provided on the inner surface of the bottom wall 211 of the compression groove, which can move along the depth direction y of the compression groove 210, and the projection of the abutting surface of the gasket abutting against the pole piece 30 in the vertical plane of the depth direction y of the compression groove 210 completely overlaps with the projection of the cross section of the pole piece 30 in the vertical plane. Among them, at least part of the resilient member 23 passes through the first opening 214 and is connected to the gasket, and the gasket provides a resilient force to the pole piece 30 in the compression groove 210.

[0137] In this way, it is not necessary to punch the rebound hole 212 on the bottom wall 211 of the compression groove, and the gasket and the rebound member 23 can provide a rebound force for the pole piece 30, so that the pole piece 30 after the test is ejected from the compression groove 210. This method can reduce the interference of the rebound hole 212 on the bottom wall on the compression state under the compression state, and improve the reliability of the test results.

[0138] In some embodiments, the second pressure piece 22 is configured to be at least partially pressed into the compression groove 210 to apply pressure to the pole piece 30; in the compressed state, the projection of the abutting surface between the second pressure piece 22 and the pole piece 30 in the vertical plane in the depth direction y completely overlaps with the projection of the cross section of the pole piece 30 in the vertical plane in the depth direction y.

[0139] In this way, the pressure applied by the second pressing member 22 to the pole piece 30 is more evenly distributed, thereby improving the consistency and accuracy of the compression of the pole piece 30. At the same time, since the projections of the second pressing member 22 and the pole piece 30 in contact completely overlap, the bias phenomenon can be effectively reduced, further improving the accuracy of the test data.

[0140] For example, in one application scenario, the compression groove 210 is a cylindrical groove, and the second pressure piece 22 includes a cylindrical pressing column, and the projection of the abutting surface between the cylindrical pressing column and the pole piece 30 in the vertical plane in the depth direction y completely overlaps with the projection of the cross section of the pole piece 30 in the vertical plane in the depth direction y.

[0141] In some embodiments, the second pressing member 22 includes a pressing portion 221 and a pressing base 222. The pressing portion 221 is arranged on the pressing base 222. The pressing portion 221 is configured to be at least partially pressed into the compression groove 210 to apply pressure to the pole piece 30. In the compressed state, along the depth direction y of the compression groove 210, the projection of the pressing base 222 covers the projection of the pressing portion 221.

[0142] When entering the compression state, the pressing portion 221 is arranged on the side of the pressing base 222 close to the first pressing member 21. Applying pressure to the pressing base 222 can press the pressing portion 221 at least partially into the compression groove 210, thereby applying pressure to the pole piece 30. This arrangement can increase the force-bearing area of ​​the second pressing member 22 by using the pressing base 222, improve the operating efficiency, and improve the uniformity of the force applied to the pressing portion 221, thereby making the force applied by the pressing portion 221 to the pole piece 30 more evenly distributed, thereby improving the consistency and accuracy of the compression of the pole piece 30.

[0143] In one application scenario, the pressing base 222 includes a disc-shaped pressing base, the pressing portion 221 includes a cylindrical pressing column, and the compression groove 210, the cylindrical pressing column, and the disc-shaped pressing base are coaxially arranged to further improve force uniformity.

[0144] In some embodiments, the pole piece 30 compression rebound test device also includes a first driving member, which is configured to drive the second pressing member 22 to move toward the first pressing member 21 in a compressed state, so that the second pressing member 22 is at least partially pressed into the compression groove 210 through the notch of the compression groove 210.

[0145] This arrangement can improve the degree of automation of the test and improve the convenience of operation. In one application scenario, the first driving member is a press, which can drive the second pressing member 22 to move toward the first pressing member 21, so that the second pressing member 22 is at least partially pressed into the compression groove 210 through the notch of the compression groove 210; in one application scenario, the first driving member can also drive the rebound member 23 to move, so that the rebound member 23 provides a rebound force to the pole piece 30 in the compression groove 210. For example, in some embodiments, in the rebound state, the first driving member drives at least a portion of the rebound portion 231 of the rebound member 23 to move from the rebound hole 212 of the bottom wall 211 of the compression groove toward the compression groove 210, so as to realize the ejection of the pole piece 30. For example, in other embodiments, in the rebound state, the first driving member drives the rebound member 23 to move along the depth direction y of the compression groove 210 from the bottom wall 211 of the compression groove toward the notch of the compression groove 210, thereby driving the gasket connected to the rebound member 23 to move along the depth direction y of the compression groove 210 from the bottom wall 211 of the compression groove toward the notch of the compression groove 210, so as to realize the pop-up of the pole piece 30.

[0146] In some embodiments, the pole piece 30 compression rebound test device further includes a second driving member, which is used to drive the resilient member 23 to move, so that the resilient member 23 provides a resilient force to the pole piece 30 in the compression groove 210. That is, the first driving member is used to drive the second pressing member 22, and the second driving member is used to drive the resilient member 23.

[0147] In some embodiments, the cylindrical pressure column is disposed at the center of the disc-shaped pressure base, and the cylindrical rebound column is disposed at the center of the disc-shaped rebound base to improve the uniformity of force when applying force.

[0148] In some application scenarios, the pole piece compression modulus A can be calculated using the following formula 1-1.

[0149] ……1-1

[0150] Wherein, A represents the compression modulus of the pole piece, F is the rated load applied to the pole piece 30, S is the force-bearing area of ​​the pole piece 30, x2 is the thickness of the pole piece 30 after compression in the compressed state, and x1 is the thickness of the pole piece 30 before compression. Specifically, the pole piece 30 is placed in the compression groove 210, and the thickness x1 of the pole piece 30 before compression can be obtained; then the rated load F is applied to enter the compression state, and the thickness x2 of the pole piece 30 after compression can be measured.

[0151] In some application scenarios, the pole piece rebound data B can be calculated using the following formula 1-2.

[0152] ……1-2

[0153] Among them, B represents the pole piece rebound data, x3 is the thickness of the pole piece 30 after a preset time in the compression release state, and x2 is the thickness of the pole piece 30 after compression in the compression state. Specifically, in the compression release state, the rated load F applied to the pole piece 30 is removed, and the pole piece 30 will rebound in thickness in the compression groove 210. By setting the preset time, the rebound characteristics of the pole piece 30 can be accurately evaluated through data measurement. After the test is completed, the pole piece 30 can be ejected from the compression groove 210 using the rebound member 23.

[0154] In some embodiments, a compression rebound test device for a pole piece 30 includes a first pressure piece 21, a second pressure piece 22, and a rebound piece 23. The first pressure piece 21 is provided with a compression groove 210, and the compression groove 210 is used to set the pole piece 30; the second pressure piece 22 is configured to apply pressure to the pole piece 30 located in the compression groove 210; the rebound piece 23 is configured to at least provide a rebound force to the pole piece 30 in the compression groove 210.

[0155] Among them, the bottom wall 211 of the compression groove is provided with a rebound hole 212, and the rebound member 23 includes a cylindrical rebound column and a disc-shaped rebound base. The cylindrical rebound column is arranged on a side of the disc-shaped rebound base close to the first pressure member 21, and the cylindrical rebound column is configured to extend at least partially from the rebound hole 212 into the compression groove 210.

[0156] In the rebound state, along the depth direction y of the compression groove 210 , the projection of the disc-shaped rebound base covers the projection of the cylindrical rebound column, and the outer diameter of the cylindrical rebound column is 1 mm smaller than the inner diameter of the rebound hole 212 .

[0157] The compression groove 210 is a cylindrical groove, the rebound hole 212 is a circular hole, and the compression groove 210 , the rebound hole 212 , the rebound portion 231 , and the rebound base 232 are coaxially arranged.

[0158] Among them, in the vertical plane of the depth direction y of the compression groove 210, the geometric shape and size of the cross section of the pole piece 30 are the same as the geometric shape and size of the compression groove 210, so that the edge of the pole piece 30 arranged in the compression groove 210 abuts against the inner surface of the side wall 213 of the compression groove.

[0159] The second pressing member 22 includes a cylindrical pressing column and a disc-shaped pressing base. The cylindrical pressing column is arranged on the disc-shaped pressing base. The cylindrical pressing column is configured to be at least partially pressed into the compression groove 210 to apply pressure to the pole piece 30. In the compressed state, the projection of the contact surface between the cylindrical pressing column and the pole piece 30 in the vertical plane in the depth direction y and the projection of the cross section of the pole piece 30 in the vertical plane in the depth direction y completely overlap. In the compressed state, along the depth direction y, the projection of the disc-shaped pressing base covers the projection of the cylindrical pressing column. The compression groove 210, the cylindrical pressing column, and the disc-shaped pressing base are coaxially arranged.

[0160] The outer surface of the side wall 213 of the compression groove is provided with a plurality of scale marks 40 arranged along the depth direction y of the compression groove 210 .

[0161] A first opening 214 is provided on the side wall 213 of the compression groove, which is connected to the compression groove 210 and extends along the depth direction y of the compression groove 210 . A plurality of scale marks 40 are arranged on the outer surface of the hole wall of the first opening 214 along the extension direction of the first opening 214 .

[0162] The first opening 214 extends from the slot opening of the compression slot 210 to the bottom of the compression slot 210 along the depth direction y; and a plurality of scale marks 40 are arranged from the slot opening of the compression slot 210 to the bottom of the compression slot 210 along the depth direction y.

[0163] The pole piece 30 compression rebound test device further comprises a press, which drives the second pressing piece 22 to move toward the first pressing piece 21 in a compressed state, so that the cylindrical pressing column is at least partially pressed into the compression groove 210 through the notch of the compression groove 210 .

[0164] The pole piece compression modulus can be calculated using the above formula 1-1, and the pole piece rebound data can be calculated using the above formula 1-2. After the test is completed, a cylindrical rebound column is used to pass through the rebound hole 212 to push the pole piece 30 out of the compression groove 210.

[0165] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A pole piece compression rebound test device, characterized in that: include: A first pressing piece, provided with a compression groove, wherein the compression groove is used to arrange the pole piece; a second pressing member, the second pressing member being configured to apply pressure to the pole piece located in the compression groove; A resilient member is configured to provide a resilient force to at least the pole piece in the compression groove.

2. The pole piece compression rebound test device according to claim 1, characterized in that: The bottom wall of the compression groove is provided with a rebound hole. In the rebound state, at least a portion of the rebound member extends from the rebound hole into the compression groove to provide a rebound force to the pole piece in the compression groove.

3. The pole piece compression rebound test device according to claim 2, characterized in that: The resilient member includes a resilient portion and a resilient base, the resilient portion is disposed on a side of the resilient base close to the first pressing member, and the resilient portion is configured to at least partially extend from the resilient hole into the compression groove.

4. The pole piece compression rebound test device according to claim 3, characterized in that: In the rebound state, along the depth direction of the compression groove, the projection of the rebound base covers the projection of the rebound portion.

5. The pole piece compression rebound test device according to claim 1, characterized in that: The compression groove is a cylindrical groove.

6. The pole piece compression rebound test device according to claim 3, characterized in that: The compression groove is a cylindrical groove, the rebound hole is a circular hole, the rebound part is a cylindrical rebound column, and the rebound base is a disc-shaped rebound base; the compression groove, the rebound hole, the rebound part, and the rebound base are coaxially arranged.

7. The pole piece compression rebound test device according to claim 1, characterized in that: The outer surface of the side wall of the compression groove is provided with a plurality of scale marks arranged along the depth direction of the compression groove.

8. The pole piece compression rebound test device according to claim 7, characterized in that: The side wall is provided with a first opening which is connected with the compression groove and extends along the depth direction, and the plurality of scale marks are arranged on the outer surface of the hole wall of the first opening along the extension direction of the first opening.

9. The pole piece compression rebound test device according to claim 8, characterized in that: The first opening extends from the notch opening of the compression groove to the bottom of the compression groove along the depth direction; the multiple scale marks are arranged from the notch opening of the compression groove to the bottom of the compression groove along the depth direction.

10. The pole piece compression rebound test device according to claim 1, characterized in that: In a vertical plane in the depth direction of the compression groove, the geometric shape and size of the cross section of the pole piece are the same as the geometric shape and size of the compression groove, so that the edge of the pole piece arranged in the compression groove abuts against the inner surface of the side wall of the compression groove.

11. The pole piece compression rebound test device according to claim 10, characterized in that: The second pressing member is configured to be at least partially pressed into the compression groove to apply pressure to the pole piece; in the compressed state, the projection of the abutting surface of the second pressing member and the pole piece in the vertical plane in the depth direction completely overlaps with the projection of the cross section of the pole piece in the vertical plane in the depth direction.

12. The pole piece compression rebound test device according to claim 1, characterized in that: The second pressing member includes a pressing portion and a pressing base, wherein the pressing portion is arranged on the pressing base, and the pressing portion is configured to be at least partially pressed into the compression groove to apply pressure to the pole piece; in a compressed state, along the depth direction of the compression groove, the projection of the pressing base covers the projection of the pressing portion.

13. The pole piece compression rebound test device according to claim 1, characterized in that: Also includes: The first driving member is configured to drive the second pressing member to move toward the first pressing member in a compressed state, so that the second pressing member is at least partially pressed into the compression groove through the notch of the compression groove.

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