Battery monomer, battery device, energy storage device and electric equipment

Abstract

The utility model relates to the technical field of battery equipment, and discloses a battery monomer, a battery device, an energy storage device and electric equipment. The battery cell includes: a case formed with an accommodating space and an open end; the electrode assembly is mounted in the accommodating space, the electrode assembly comprises an anode plate and a cathode plate, and the anode plate and the cathode plate are stacked and arranged in an insulating manner; the end cover covers the opening end and comprises an insulating inner cover, the insulating inner cover comprises a body part and a convex structure connected to the body part, the convex structure is located on the side, facing the containing space, of the body part and is arranged in the circumferential direction, the end, away from the body part, of the convex structure is provided with an end plane, and the end plane abuts against the edge area of one end of the electrode assembly; and the cross section width of the end plane is greater than the thickness of the anode plate or the cathode plate. By applying the technical scheme, the problem that dendritic crystals are separated out from the crushed position of an anode piece or a cathode piece due to the fact that the anode piece or the cathode piece of the electrode assembly is possibly crushed by the circumferential convex ribs is solved.

Description

Technical Field

[0001] This application belongs to the field of battery equipment technology, and in particular relates to a battery cell, battery device, energy storage device and electrical equipment. Background Technology

[0002] In battery cells of related technologies, when the electrode assembly is assembled into the housing and the end cap is closed, the corresponding ends of the end cap and the electrode assembly achieve local contact through circumferential ribs on the end cap, thereby stably confining the electrode assembly within the housing. To reduce the interference of the circumferential ribs on the assembly of other components due to excessive space occupied by them, current battery cells have relatively small cross-sectional widths and almost blade-like ends, making the contact between the circumferential ribs and the electrode assembly nearly a line contact.

[0003] During the use of a battery cell, it is subject to external forces, such as collisions with foreign objects or bumps during transportation, which can cause the electrode assembly to wobble relative to the housing and end caps within the casing. Because the contact between the circumferential ribs and the electrode assembly is close to a line contact, the pressure exerted by the circumferential ribs on the ends of the electrode assembly is relatively high. The circumferential ribs may damage the anode or cathode plates of the electrode assembly, potentially leading to dendrite precipitation at the damaged locations, which could cause an internal short circuit in the battery cell. Utility Model Content

[0004] The purpose of this application is to provide a battery cell, battery device, energy storage device, and electrical equipment, including but not limited to solving the problem that circumferential ribs may damage the anode or cathode plates of the electrode assembly, which may lead to dendrite precipitation at the damaged locations of the anode or cathode plates.

[0005] To achieve the above objectives, according to a first aspect of an embodiment of this application, a battery cell is provided, comprising:

[0006] The shell has a receiving space and an open end communicating with the receiving space;

[0007] An electrode assembly is installed in a receiving space. The electrode assembly includes an anode plate and a cathode plate, which are stacked and insulated from each other.

[0008] An end cap is fitted over an open end. The end cap includes an insulating inner cover. The insulating inner cover includes a body portion and a protruding structure connected to the body portion. The protruding structure is located on the side of the body portion facing the receiving space and is circumferentially arranged. The end of the protruding structure away from the body portion has an end plane. The end plane abuts against the edge region of one end of the electrode assembly. Furthermore, the cross-sectional width of the end plane is greater than the thickness of the anode or cathode plate.

[0009] In the battery cell of this application embodiment, when the electrode assembly is assembled into the housing and the end cap is closed, the protruding structure of the insulating inner cover of the end cap abuts against the edge region of one end of the electrode assembly. Since the cross-sectional width of the end plane of the protruding structure abutting the electrode assembly is greater than the thickness of the anode or cathode plate of the electrode assembly, that is, there is a surface contact between the end plane of the protruding structure and the end of the electrode assembly, and the end plane at least traverses and contacts the adjacent anode and cathode plates. Thus, compared with the circumferential ribs in the battery cell of the related art, which have a line contact with the electrode assembly, the battery cell of this application embodiment increases the contact area between the end plane of the protruding structure and the end of the electrode assembly. When the electrode assembly shakes relative to each other in the housing, the pressure of the protruding structure on the end of the electrode assembly can be reduced, reducing the possibility of the protruding structure damaging the anode or cathode plate of the electrode assembly. That is, it reduces the possibility of dendrite precipitation at the damaged position of the anode or cathode plate, leading to an internal short circuit, effectively improving the service life of the battery cell and improving the safety of the battery cell.

[0010] In some embodiments of this application, an adhesive layer is provided between the end face and the electrode assembly, and the width of the adhesive layer is greater than the thickness of the anode or cathode sheet. The end face indirectly abuts against the end of the electrode assembly through the adhesive layer, and there is a surface contact between the adhesive layer and the end of the electrode assembly. Furthermore, the adhesive layer at least spans across and contacts the adjacent anode and cathode sheets, thereby reducing the pressure of the protruding structure on the end of the electrode assembly and reducing the possibility of the protruding structure damaging the anode or cathode sheet of the electrode assembly.

[0011] In some embodiments of this application, the width of the adhesive layer is greater than or equal to the cross-sectional width of the end plane. Preferably, the width of the adhesive layer is greater than the cross-sectional width of the end plane, thereby further reducing the pressure exerted by the protrusion structure on the end of the electrode assembly and reducing the possibility of the protrusion structure damaging the anode or cathode plate of the electrode assembly.

[0012] In some embodiments of this application, the end plane is perpendicular to the arrangement direction of the end cap and the electrode assembly. The end plane can fully fit against the end of the electrode assembly, resulting in a more stable contact between the end plane and the end of the electrode assembly and reducing the possibility of the electrode assembly wobbling relative to the protruding structure.

[0013] In some embodiments of this application, the cross-section of the protruding structure is a trapezoid that gradually widens from the body portion to the electrode assembly. Without increasing the space occupied by the protruding structure within the accommodating space, the trapezoidal cross-section of the protruding structure ensures surface contact between the end face of the protruding structure and the end of the electrode assembly, thereby effectively reducing the pressure exerted by the protruding structure on the end of the electrode assembly.

[0014] In some embodiments of this application, the protrusion structure is a circumferentially continuous integral structure; or, the protrusion structure includes multiple protrusions spaced apart circumferentially. This effectively disperses the interaction force between the end face of the protrusion structure and the end of the electrode assembly, thereby effectively reducing the pressure of the protrusion structure on the end of the electrode assembly and reducing the possibility of the protrusion structure damaging the anode or cathode plate of the electrode assembly.

[0015] In some embodiments of this application, the body portion and the protruding structure are integrally formed, which is beneficial to improving the production efficiency of manufacturing insulating inner covers.

[0016] In some embodiments of this application, the electrode assembly is a stacked structure or a wound structure; and the accommodating space is a square space.

[0017] In some embodiments of this application, the anode plate is provided with a negative electrode tab, the cathode plate is provided with a positive electrode tab, the end of the housing opposite to the open end is a closed end, the positive electrode tab and the negative electrode tab are both located at the end of the electrode assembly facing the open end, and the positive electrode tab and the negative electrode tab are both inserted through the body portion.

[0018] In some embodiments of this application, the anode plate is provided with a negative electrode tab, the cathode plate is provided with a positive electrode tab, the opening end includes a first opening end and a second opening end, the first opening end and the second opening end are respectively located at opposite ends of the casing, the battery cell includes a first end cap and a second end cap, the first end cap and the second end cap are respectively closed on the first opening end and the second opening end, one of the positive electrode tab and the negative electrode tab is located at the end of the electrode assembly facing the first opening end and passes through the body of the first end cap, the other of the positive electrode tab and the negative electrode tab is located at the end of the electrode assembly facing the second opening end and passes through the body of the second end cap.

[0019] According to a second aspect of an embodiment of this application, a battery device is provided. The battery device includes a battery cell as described above, the battery cell being used to store or provide electrical energy.

[0020] According to a third aspect of the embodiments of this application, an energy storage device is provided. Wherein:

[0021] The energy storage device includes battery cells as described above, which are used to store or provide electrical energy;

[0022] Alternatively, the energy storage device may include a battery device as described above, which is used to store or provide electrical energy.

[0023] According to a fourth aspect of an embodiment of this application, an electrical appliance is provided. The electrical appliance includes an electrical load; and,

[0024] The electrical equipment also includes multiple battery cells as described above, and the electrical load is electrically connected to the multiple battery cells;

[0025] Alternatively, the electrical equipment may also include a battery device as described above, with the electrical load electrically connected to the battery device;

[0026] Alternatively, the electrical equipment may also include an energy storage device as described above, with the electrical load electrically connected to the energy storage device;

[0027] Alternatively, the electrical equipment may also include an energy storage system as described above, with the electrical load electrically connected to the energy storage system;

[0028] Among them, individual battery cells or battery devices are used to store or provide electrical energy. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the assembly structure of the first battery cell in an embodiment of this application;

[0031] Figure 2 for Figure 1 A schematic diagram of the exploded battery cell is shown.

[0032] Figure 3 for Figure 2 Enlarged view of point S in the middle;

[0033] Figure 4 for Figure 1 A schematic partial cross-sectional view of a single battery cell along the AA direction is shown.

[0034] Figure 5 for Figure 4 Enlarged view of point B in the middle;

[0035] Figure 6 This is a partial cross-sectional schematic diagram of a second type of battery cell according to an embodiment of this application;

[0036] Figure 7 This is a partial cross-sectional schematic diagram of a third type of battery cell according to an embodiment of this application;

[0037] Figure 8 for Figure 7 Enlarged view of point C in the middle;

[0038] Figure 9 This is a cross-sectional schematic diagram of the fourth type of battery cell according to an embodiment of this application;

[0039] Figure 10 This is an exploded view of the fifth type of battery cell in this application embodiment;

[0040] Figure 11 This is an exploded view of the sixth type of battery cell in an embodiment of this application;

[0041] Figure 12 This is an exploded view of a battery device according to an embodiment of this application;

[0042] Figure 13 This is an exploded view of another battery device according to an embodiment of this application;

[0043] Figure 14 This is a schematic diagram of the structure of an energy storage device according to an embodiment of this application;

[0044] Figure 15 This is a schematic diagram of the structure of an electrical device according to an embodiment of this application.

[0045] The figures in the diagram are labeled as follows:

[0046] 100. Battery cell;

[0047] 10. Shell; 11. Receiving space; 12. Opening end; 121. First opening end; 122. Second opening end;

[0048] 20. Electrode assembly; 21. Anode plate; 211. Negative electrode tab; 22. Cathode plate; 221. Positive electrode tab; 23. Diaphragm;

[0049] 30. End cap; 31. Insulating inner cap; 311. Body part; 312. Protruding structure; 313. End plane; 314. Protrusion; 32. Outer cap; 33. Pole post structure; 301. First end cap; 302. Second end cap;

[0050] 40. Adhesive layer;

[0051] 200. Battery assembly; 201. Box body; 202. Box cover; 203. Assembly space;

[0052] 300. Energy storage device; 310. Cabinet;

[0053] 400. Electrical equipment; 410. Electrical load; 420. Control device; 430. Chassis; 440. Wheel. Detailed Implementation

[0054] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0055] In the description of this application, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0056] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0057] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0058] Currently, judging from market trends, the application of battery devices is becoming increasingly widespread. Battery devices are not only used in energy storage power systems such as hydropower, thermal power, wind power, and solar power plants (battery devices used in these applications are generally referred to as energy storage batteries), but also widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace (battery devices used in these applications are generally referred to as power batteries). With the continuous expansion of the application fields of battery devices and their increasingly widespread use, the market's requirements for battery device lifespan and safety are also constantly increasing.

[0059] A battery device comprises multiple individual battery cells, which are installed within a battery casing and connected in series, parallel, or mixed connections via terminals to meet the rated output voltage and current requirements of the battery device. Therefore, the lifespan and operational safety of the individual battery cells are key factors determining the lifespan and operational safety of the entire battery device.

[0060] In related battery cells, electrode assemblies are assembled into a housing, and then end caps are closed. To stably confine the electrode assemblies within the housing, circumferential ribs on the end caps abut against the corresponding ends of the electrode assemblies, thus stabilizing the electrode assemblies within the housing. Currently, the cross-sectional width of the circumferential ribs on the end caps is relatively small, and the ends of the ribs are almost blade-shaped. While this solves the problem of excessive space occupied by the circumferential ribs interfering with the assembly of other components, it also makes the contact between the circumferential ribs and the electrode assemblies resemble line contact. Consequently, during the use of the battery cell, when the battery cell is affected by external forces, such as collisions with foreign objects or transportation bumps, the effects on the battery cell, and subsequently on the electrode assemblies, cause the electrode assemblies to wobble relative to the housing and end caps within the housing. Because the contact form between the circumferential rib and the electrode assembly is close to the line contact (hereinafter referred to as the line contact form), the pressure exerted by the circumferential rib on the end of the electrode assembly is relatively large. The circumferential rib may damage the anode or cathode plate of the electrode assembly, which may cause dendrites to precipitate at the damaged anode or cathode plate, potentially causing an internal short circuit in the battery cell.

[0061] Based on the above considerations, embodiments of this application provide a battery cell in which, when the electrode assembly is assembled into the housing and the end cap is closed, the protruding structure of the insulating inner cover of the end cap abuts against the edge region of one end of the electrode assembly. Since the cross-sectional width of the end plane of the protruding structure abutting the electrode assembly is greater than the thickness of the anode or cathode plate of the electrode assembly, that is, there is a surface contact between the end plane of the protruding structure and the end of the electrode assembly, and the end plane at least traverses and contacts the adjacent anode and cathode plates. Thus, compared to the line contact between the circumferential ribs and the electrode assembly in battery cells of related technologies, the battery cell of this application increases the contact area between the end plane of the protruding structure and the end of the electrode assembly. When the electrode assembly shakes relative to each other in the housing, the pressure of the protruding structure on the end of the electrode assembly can be reduced, reducing the possibility of the protruding structure damaging the anode or cathode plate of the electrode assembly. This reduces the possibility of lithium precipitation at the damaged location of the anode or cathode plate, forming lithium dendrites and causing an internal short circuit, effectively improving the service life and safety of the battery cell.

[0062] Furthermore, the battery cells provided in the embodiments of this application are applied to battery devices, energy storage devices, and electrical equipment, thereby improving the service life and safety of battery devices, energy storage devices, and electrical equipment.

[0063] 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.

[0064] According to a first aspect of the embodiments of this application, embodiments of this application provide a battery cell 100. For example... Figures 1 to 5 As shown, the battery cell 100 includes a housing 10, an electrode assembly 20, and an end cap 30. The housing 10 forms a receiving space 11 and an opening end 12 communicating with the receiving space 11. The electrode assembly 20 is installed in the receiving space 11. The electrode assembly 20 includes an anode plate 21 and a cathode plate 22. The anode plate 21 and the cathode plate 22 are stacked and insulated from each other. The end cap 30 covers the opening end 12. The end cap 30 includes an insulating inner cover 31. The insulating inner cover 31 includes a body portion 311 and a protrusion structure 312 connected to the body portion 311. The protrusion structure 312 is located on the side of the body portion 311 facing the receiving space 11 and is arranged circumferentially. The end of the protrusion structure 312 away from the body portion 311 has an end plane 313. The end plane 313 abuts against the edge region of one end of the electrode assembly 20. Furthermore, the cross-sectional width of the end plane 313 is greater than the thickness of the anode plate 21 or the cathode plate 22.

[0065] In the battery cell 100 provided in the embodiments of this application, when the electrode assembly 20 is assembled into the housing 10 and the end cover 30 is closed, the protruding structure 312 of the insulating inner cover 31 of the end cover 30 abuts against the edge region of one end of the electrode assembly 20. Since the cross-sectional width of the end plane 313 of the protruding structure 312 abutting against the electrode assembly 20 is greater than the thickness of the anode plate 21 or cathode plate 22 of the electrode assembly 20, that is, the end plane 313 of the protruding structure 312 and the end of the electrode assembly 20 are in surface contact, and the end plane 313 at least spans across and contacts the adjacent anode plate 21 and cathode plate 22. In this way, compared with the line contact between the circumferential ribs and the electrode assembly in the battery cell of the related technology, the battery cell 100 of the present application increases the contact area between the end plane 313 of the protrusion structure 312 and the end of the electrode assembly 20. When the electrode assembly 20 shakes relative to the housing 10, the pressure of the protrusion structure 312 on the end of the electrode assembly 20 can be reduced, reducing the possibility that the protrusion structure 312 will damage the anode plate 21 or cathode plate 22 of the electrode assembly 20. In other words, it reduces the possibility that dendrites will precipitate at the damaged position of the anode plate 21 or cathode plate 22, resulting in an internal short circuit, effectively improving the service life of the battery cell 100.

[0066] During the use of the battery cell 100, when dendrites precipitate at the damaged locations of the anode plate 21 or cathode plate 22 of the electrode assembly 20, the dendrites can pierce the separator 23, leading to a short circuit between the anode plate 21 and the cathode plate 22 through the dendrites, i.e., an internal short circuit in the battery cell 100. This short circuit between the anode plate 21 and the cathode plate 22 through the dendrites causes the electrode assembly 20 to generate a large amount of heat, ultimately leading to thermal runaway within the battery cell 100, causing safety issues in its use. The battery cell 100 provided in the embodiments of this application can reduce the pressure of the protruding structure 312 on the ends of the electrode assembly 20, reducing the possibility of the protruding structure 312 damaging the anode plate 21 or cathode plate 22 of the electrode assembly 20, thus reducing the possibility of dendrite precipitation at the damaged locations of the anode plate 21 or cathode plate 22 leading to an internal short circuit. This effectively reduces the possibility of thermal runaway within the battery cell 100, thereby effectively improving the safety of the battery cell 100 in use.

[0067] "The transverse width of end plane 313" refers to: taking a section of the protruding structure 312, and in a cross-section of this section perpendicular to the tangent direction of the protruding structure 312 and perpendicular to the plane where the end cap 30 is located (when the protruding structure 312 is a straight section, the tangent direction is the extension direction of the soil structure 312; when the protruding structure 312 is an arc section, the tangent direction is the tangent direction at a certain point on the protruding structure 312), the width of the side of this cross-section away from the main body 311 is the transverse width of end plane 313, i.e. Figures 4 to 9 The width W of the cross section of the protruding structure 312 shown in the figure.

[0068] "Dendrite precipitation at the damaged location of anode plate 21 or cathode plate 22" refers to the following: In battery cell 100, the precipitation of dendrites at the damaged location of anode plate 21 or cathode plate 22 is mainly caused by the following factors: 1. Formation and characteristics of SEI film (i.e., solid electrolyte membrane): After battery cell 100 is assembled, the active material on the electrode reacts with the organic solvent in the electrolyte due to its high reactivity, forming SEI film. 1. SEI film: This film is an ionic conductor but an electronic insulator. Ions of the active material (such as lithium ions) can pass through it and deposit on the electrode surface. However, due to the characteristics of the active material ions, electrolyte, SEI film, and charging and discharging conditions, the deposition distribution is uneven. 2. Nucleation and growth stage: The formation of dendrites is divided into three stages. First, the SEI film is formed. Second, the nucleation stage, that is, the uneven accumulation of precipitation causes some places to bulge and break through the SEI film. Finally, the growth stage, the dendrites grow in the length direction to become visible dendrites. 3. Overcharging and crystallization: During overcharging, the ions of the negative electrode active material (such as lithium ions) are saturated, and the excess ions are deposited in the form of metal. 4. High-current charging: During high-current charging, ions of the active material on the negative electrode surface do not have enough time to diffuse inward and are deposited on the electrode surface. 5. Electrode edge effect: The electrode edge is affected by the edge effect, resulting in a high current density and easy crystallization of the negative electrode. 6. Non-uniformity of positive and negative electrode surfaces: Non-uniformity of positive and negative electrode surfaces, such as uneven coating, impurities mixed in with the active material, or excessive thickness at the positive or negative electrode head, will affect dendrite formation. 7. Ion concentration gradient and distribution of active material: After the ions of the active material are extracted from the positive electrode material, they pass through the electrolyte and the separator and accept electrons at the negative electrode. During charging, the ion concentration of the active material in the positive electrode gradually increases, while the ion concentration of the active material in the negative electrode decreases due to continuous electron acceptance, leading to the formation of local space charge and dendrite structure. 8. Current density: The magnitude of current density is one of the many factors affecting dendrite growth. At high current densities, the ion deposition rate of the active material exceeds the formation rate of the SE I film, resulting in incomplete SE I film. When the anode surface is covered by an I-film, in areas without or with poor SEI film protection, ion deposits of active material will grow into moss-like dendrites following a surface growth pattern. 9. Electrode overpotential: The charging method and the magnitude of the electrode overpotential also significantly affect dendrite growth. Pulse charging can significantly suppress dendrite growth at high overpotentials, but increasing the electrode overpotential also increases the tendency for dendrite formation. These factors combined may cause dendrites to precipitate at the damaged locations on the anode plate 21 or cathode plate 22 in the battery cell 100.

[0069] In some embodiments of this application, such as Figure 4 and Figure 5As shown, an adhesive layer 40 is provided between the end face 313 and the electrode assembly 20. The two sides of the adhesive layer 40 abut against the end face 313 and the end of the electrode assembly 20, respectively. That is, the end face 313 indirectly abuts against the end of the electrode assembly 20 through the adhesive layer 40. The adhesive layer 40 and the end of the electrode assembly 20 are in surface contact. Furthermore, the width of the adhesive layer 40 is greater than the thickness of the anode plate 21 or cathode plate 22, ensuring that the adhesive layer 40 at least spans across and contacts adjacent anode plates 21 and cathode plates 22. This reduces the pressure of the protrusion structure 312 on the end of the electrode assembly 20, lowering the possibility of the protrusion structure 312 damaging the anode plate 21 or cathode plate 22 of the electrode assembly 20. Moreover, the adhesive layer 40 has adhesive properties, bonding the end face 313 to the end of the electrode assembly 20, thus maintaining a stable relative position between the protrusion structure 312 and the electrode assembly 20. Thus, even when the battery cell 100 is subjected to external force, due to the adhesive layer 40's bonding restriction between the end face 313 and the electrode assembly 20, the electrode assembly 20 only tends to wobble relative to the protruding structure 312 within the housing space 11 of the casing 10, but does not detach from the end face 313. This reduces the possibility of the electrode assembly 20 detaching from the end face 313 of the protruding structure 312 and then wobbling in the opposite direction and colliding with the protruding structure 312. This reduces the possibility of the protruding structure 312 damaging the anode plate 21 or cathode plate 22 of the electrode assembly 20, and also reduces the possibility of dendrites precipitating at the damaged location of the anode plate 21 or cathode plate 22, leading to an internal short circuit.

[0070] In some embodiments of this application, the width of the adhesive layer 40 is greater than or equal to the cross-sectional width of the end plane 313. Since the cross-sectional width of the end plane 313 where the protrusion structure 312 abuts against the electrode assembly 20 is greater than the thickness of the anode sheet 21 or cathode sheet 22 of the electrode assembly 20, and the width of the adhesive layer 40 is greater than or equal to the cross-sectional width of the end plane 313, the contact surface between the adhesive layer 40 and the end of the electrode assembly 20 is greater than or equal to the contact surface where the end plane 313 directly abuts against the end of the electrode assembly 20. This further reduces the pressure of the protrusion structure 312 on the end of the electrode assembly 20, reducing the possibility of the protrusion structure 312 damaging the anode sheet 21 or cathode sheet 22 of the electrode assembly 20. In the battery cell 100 of the embodiments of this application, the width of the adhesive layer 40 is preferably greater than the cross-sectional width of the end plane 313.

[0071] The adhesive layer 40 includes, but is not limited to, double-sided adhesive and structural adhesive. Along the arrangement direction from the electrode assembly 20 to the end cap 30, the height of the adhesive layer 40 is relatively small compared to the height of the protruding structure 312 or other components. The adhesive layer 40 does not occupy excessive space within the receiving space 11, thus it does not interfere with the assembly position of other components within the receiving space 11, nor does it increase the overall height of the battery cell 100. Furthermore, the adhesive layer 40 has a certain degree of flexibility. When the battery cell 100 is subjected to external force, the adhesive layer 40 has a buffering and energy-absorbing effect on the tendency of the electrode assembly 20 to sway relative to the protruding structure 312, helping to reduce the interaction force between the protruding structure 312 and the end of the electrode assembly 20, thereby reducing the possibility of the protruding structure 312 damaging the anode plate 21 or cathode plate 22 of the electrode assembly 20.

[0072] In the battery cell 100 of the embodiments of this application, both ends of the electrode assembly 20 are flat. To improve the energy density of the battery cell 100, the end cap 30 is configured as a flat piece parallel to the flat ends of the electrode assembly 20. That is, the flat ends of the electrode assembly 20 are perpendicular to the arrangement direction of the end cap 30 and the electrode assembly 20. Therefore, in some embodiments of this application, the end plane 313 is perpendicular to the arrangement direction of the end cap 30 and the electrode assembly 20. In this way, the end plane 313 can fully fit against the end of the electrode assembly 20, resulting in a more stable contact between the end plane 313 and the end of the electrode assembly 20, reducing the possibility of the electrode assembly 20 wobbling relative to the protruding structure 312. This effectively reduces the possibility of the protruding structure 312 damaging the anode plate 21 or cathode plate 22 of the electrode assembly 20.

[0073] In some embodiments of this application, such as Figure 7 and Figure 8 As shown, the cross-section of the protruding structure 312 is a trapezoid that gradually expands from the body portion 311 to the electrode assembly 20. Compared with the circumferential ribs of the related art, in the battery cell 100 provided in the embodiment of this application, without increasing the space occupied by the protruding structure 312 in the receiving space 11, the trapezoidal cross-section of the protruding structure 312 can ensure that the end plane 313 of the protruding structure 312 is in surface contact with the end of the electrode assembly 20, thereby effectively reducing the pressure of the protruding structure 312 on the end of the electrode assembly 20 and reducing the possibility that the protruding structure 312 will damage the anode plate 21 or cathode plate 22 of the electrode assembly 20.

[0074] like Figure 2 , Figure 4 , Figure 7 , Figures 9 to 11As shown, in some embodiments of this application, the protruding structure 312 is a circumferentially continuous integral structure. That is, the protruding structure 312 continuously abuts against the end of the electrode assembly 20 around a full circle, so that the contact surface between the end face 313 of the protruding structure 312 and the end of the electrode assembly 20 reaches the maximum contact area. Thus, when the battery cell 100 is subjected to external force, causing the electrode assembly 20 to tend to sway relative to the protruding structure 312 within the receiving space 11 of the housing 10, the interaction force between the end face 313 of the protruding structure 312 and the end of the electrode assembly 20 is effectively dispersed because the contact surface between the end face 313 of the protruding structure 312 and the end of the electrode assembly 20 reaches the maximum contact area. This effectively reduces the pressure of the protruding structure 312 on the end of the electrode assembly 20, and reduces the possibility of the protruding structure 312 damaging the anode plate 21 or cathode plate 22 of the electrode assembly 20.

[0075] Since the wobbling of the electrode assembly 20 within the receiving space 11 is a multi-degree-of-freedom relative motion with respect to the protruding structure 312, rather than a linear reciprocating motion along the arrangement direction from the electrode assembly 20 to the end cap 30, in some embodiments of this application, the protruding structure 312 includes a plurality of protrusions 314, which are spaced apart circumferentially, such as... Figure 6 As shown. This also achieves the same technical effect as "the protruding structure 312 is a circumferentially continuous integral structure". That is, when the battery cell 100 is subjected to external force, causing the electrode assembly 20 to tend to sway relative to the protruding structure 312 within the housing space 11 of the casing 10, the contact area between the end plane 313 of the protruding structure 312 and the end of the electrode assembly 20 still tends to be large. This can effectively disperse the interaction force between the end plane 313 of the protruding structure 312 and the end of the electrode assembly 20, thereby effectively reducing the pressure of the protruding structure 312 on the end of the electrode assembly 20 and reducing the possibility of the protruding structure 312 damaging the anode plate 21 or cathode plate 22 of the electrode assembly 20.

[0076] In some embodiments of this application, the body portion 311 and the protruding structure 312 are integrally formed, meaning the insulating inner cover 31 is an integrally formed component. The insulating inner cover 31 is obtained by injection molding, improving the production efficiency of manufacturing the insulating inner cover 31. The end cover 30 also includes an outer cover 32, which is stacked and assembled with the insulating inner cover 31 to form the end cover 30. Furthermore, the outer cover 32 may be, but is not limited to, made of aluminum alloy, which effectively improves the overall strength of the end cover 30 and reduces its weight, contributing to the overall lightweighting of the battery cell 100.

[0077] In some embodiments of this application, such as Figure 2 and Figure 3As shown, the electrode assembly 20 also includes multiple separators 23, multiple anode plates 21, and multiple cathode plates 22. The separators 23, anode plates 21, and cathode plates 22 are all sheet-like, and are alternately stacked in sequence. That is, the electrode assembly 20 is a stacked structure manufactured using a stacking process, also known as a stacked battery cell. Furthermore, the receiving space 11 of the housing 10 is a square space, and the separators 23, anode plates 21, and cathode plates 22 are all square sheets adapted to the shape of the receiving space 11. In other words, the electrode assembly 20 is assembled into the receiving space 11 of the housing 10 to form a square-shell stacked battery. Because the anode plate 21, separator 23, and cathode plate 22 in the electrode assembly 20 of the prismatic laminated battery are stacked in an alternating manner, the edges of some anode plates 21 or some cathode plates 22 are prone to misalignment. That is, relative to the flat end of the ideal electrode assembly 20, the edges of some anode plates 21 protrude relative to the edges of cathode plates 22, or the edges of some cathode plates 22 protrude relative to the edges of anode plates 21. If these protruding edges are abutted by the protruding structure 312 in a line contact manner, the probability of the anode plate 21 or cathode plate 22 being damaged by pressure will be greatly increased. To reduce the possibility of the protruding edges of the anode plate 21 or the cathode plate 22 being damaged by the protruding structure 312, embodiments of this application involve the end face 313 of the protruding structure 312 contacting these protruding edges in a surface-to-surface manner. Since the cross-sectional width of the end face 313 is greater than the thickness of the anode plate 21 or the cathode plate 22 of the electrode assembly 20, the end face 313 at least spans across and contacts adjacent anode plates 21 and cathode plates 22. This reduces the pressure of the protruding structure 312 on these protruding edges and lowers the possibility of the protruding structure 312 damaging the anode plate 21 or the cathode plate 22 of the electrode assembly 20.

[0078] In some embodiments of this application, the electrode assembly 20 further includes a diaphragm 23, such as Figure 10 and Figure 11 As shown, the diaphragm 23, anode plate 21, and cathode plate 22 are all strip-shaped, and are sequentially stacked and wound together. That is, the electrode assembly 20 is a wound structure manufactured using a winding process, also known as a wound battery cell. The housing 10 used to house the wound battery cell can be a square housing, such as... Figure 10 As shown; it can also be a cylindrical shell, such as Figure 11As shown. Generally, the ends of the wound battery cells (i.e., the ends of the electrode assembly 20) formed by the winding process are relatively flat relative to the ends of the laminated battery cells. However, there are still sections of the anode sheet 21 or the cathode sheet 22 that are offset to a certain extent during winding, causing these sections to protrude from the ends of the electrode assembly 20. Similarly, if these protruding sections of the wound battery cell are contacted by the protruding structure 312 in a line-contact manner, the probability of the anode sheet 21 or the cathode sheet 22 being damaged will be greatly increased. To reduce the possibility that the protruding winding positions of the anode sheet 21 or cathode sheet 22 may be damaged by the protrusion structure 312, the embodiments of this application make the end face 313 of the protrusion structure 312 abut against these protruding winding positions in a surface contact manner. Since the cross-sectional width of the end face 313 is greater than the thickness of the anode sheet 21 or cathode sheet 22 of the electrode assembly 20, the end face 313 at least spans across and contacts the adjacent anode sheet 21 and cathode sheet 22. This can reduce the pressure of the protrusion structure 312 on these protruding winding positions and reduce the possibility that the protrusion structure 312 may damage the anode sheet 21 or cathode sheet 22 of the electrode assembly 20.

[0079] It should be noted that: the protruding edge (or a certain section of the winding position) of the anode plate 21 or cathode plate 22 is a slight protrusion, within the allowable range of assembly error, rather than a large protrusion; if the edge of the anode plate 21 or cathode plate 22 protrudes significantly, it is a defective product and must be scrapped.

[0080] Regardless of whether the battery cell 100 has a square casing or a cylindrical casing, in some embodiments of this application, such as Figures 2 to 4 , Figure 6 , Figure 7 and Figure 11 As shown, the anode plate 21 is provided with a negative electrode tab 211, and the cathode plate 22 is provided with a positive electrode tab 221. The end of the housing 10 opposite to the opening end 12 is a closed end. Both the positive electrode tab 221 and the negative electrode tab 211 are located at the end of the electrode assembly 20 facing the opening end 12. Both the positive electrode tab 221 and the negative electrode tab 211 pass through the body portion 311, and the positive electrode tab 221 and the negative electrode tab 211 are electrically connected to the corresponding electrode post structure 33 provided on the outer cover 32. That is, the battery cell 100 provided in this embodiment has a single-sided electrode structure. Alternatively, in some other embodiments of this application, whether it is a square-shell battery cell 100 or a cylindrical-shell battery cell 100, as Figure 9 and Figure 11As shown, the anode plate 21 is provided with a negative electrode tab 211, the cathode plate 22 is provided with a positive electrode tab 221, and the opening end 12 includes a first opening end 121 and a second opening end 122, which are respectively located at opposite ends of the housing 10. The battery cell 100 includes a first end cap 301 and a second end cap 302, which respectively cover the first opening end 121 and the second opening end 122. One of the tabs, 221 and 211, is located at the end of the electrode assembly 20 facing the first opening 121 and passes through the body portion 311 of the first end cap 301. The other of the tabs, 221 and 211, is located at the end of the electrode assembly 20 facing the second opening 122 and passes through the body portion 311 of the second end cap 302. Furthermore, the positive tab 221 and the negative tab 211 are electrically connected to the corresponding end cap's electrode post structure 33. In other words, the battery cell 100 provided in this embodiment has a structure with electrodes on both sides. This allows users to select either a single-sided electrode structure or a double-sided electrode structure for various application scenarios, making the battery cell 100 suitable for more diverse applications and possessing wider applicability.

[0081] 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 recharged after discharge to activate the active materials and continue to be used. The battery cell 100 can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0082] According to a second aspect of the embodiments of this application, embodiments of this application also provide a battery device 200, such as... Figure 12 and Figure 13 As shown, the battery device 200 includes multiple battery cells 100 as described above. Generally, whether the battery device 200 is assembled using battery cells 100 with square or cylindrical casings, the outline of the battery casing of the battery device 200 is square, also known as a square battery. Figure 12 and Figure 13 As shown, the battery device 200 includes a battery body 201 and a cover 202. The cover 202 closes onto the open end of the battery body 201, and the battery body 201 and the cover 202 together form an assembly space 203. Furthermore, 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.

[0083] According to a third aspect of the embodiments of this application, embodiments of this application also provide an energy storage device 300. In some embodiments of this application, the energy storage device 300 includes a battery device 200 as described above, that is, the energy storage device 300 uses one battery device 200 or multiple battery devices 200 connected in series, parallel, or mixed, such that these battery devices 200 are used to store electrical energy or provide electrical energy. In other embodiments of this application, the energy storage device 300 includes multiple battery cells 100 as described above, that is, the energy storage device 300 uses multiple battery cells 100 connected in series, parallel, or mixed, such that these battery cells 100 are used to store electrical energy or provide electrical energy.

[0084] The energy storage device 300 can be a small, portable device, such as a convenient energy storage battery used for outdoor tourism and camping, or a portable energy storage battery used by street vendors. The energy storage device 300 can also be a large, fixed, high-power industrial-grade device, such as a large energy storage power station used in a power plant. The energy storage device 300 can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems, or temporary power supply systems. The energy storage device 300 can store electrical energy as needed and output it when appropriate. For example, the energy storage device 300 can store electrical energy during off-peak hours and provide power to relevant users or electrical equipment during peak hours. Other examples include independent power supply energy storage cabinets or energy storage containers used on construction sites or in factories, and larger, portable energy storage cabinets or energy storage containers used at large event venues.

[0085] like Figure 14 As shown, the energy storage device 300 provided in the embodiments of this application is preferably an energy storage cabinet, which includes a cabinet 310 and a plurality of battery devices 200, which are stacked and assembled in the cabinet 310.

[0086] In some embodiments of this application, the energy storage device 300 may include modules such as a thermal management module, a main control module, a central control module, a power distribution module, and a fire protection module.

[0087] As an example, the thermal management module may include a liquid cooling unit that supplies coolant to each battery cell 100 or each battery device 200 via pipelines for regulating the temperature of the battery cell 100.

[0088] As an example, the main control module can serve as a battery management unit for multiple battery cells 100 or multiple battery devices 200, used to monitor and manage these cells. The main control module can monitor information such as current, voltage, power, or temperature of the multiple battery cells 100 or multiple battery devices 200. For example, it can control the charging and discharging current and voltage of the multiple battery cells 100 or multiple battery devices 200. The main control module includes modules such as an auxiliary battery management unit (SBMU) and a fusion switch.

[0089] As an example, the central control module can serve as the battery management unit of the energy storage device 300, used to monitor and manage the energy storage device 300. The central control module can monitor information such as the current, voltage, power, state of charge, or temperature of the energy storage device 300. For example, it can control the charging and discharging current and voltage of the energy storage device 300. As an example, the central control module includes modules such as an insulation monitoring module (IMM), a master battery management unit (MBMU), an Ethernet (ETH) module, and a fiber optic conversion module.

[0090] As an example, the fire protection module includes a control panel, detectors, alarm devices, etc., used to detect, alarm, or extinguish fires in the energy storage system.

[0091] As an example, the power distribution module can be used to distribute power to the modules in the energy storage device 300 that require electricity.

[0092] According to a fourth aspect of the embodiments of this application, embodiments of this application also provide an electrical appliance 400, which includes an electrical load 410.

[0093] 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.

[0094] In some embodiments of this application, the electrical device 400 further includes an energy storage device 300 as described above. That is, the electrical device 400 employs one energy storage device 300 or multiple energy storage devices 300 connected in series, parallel, or in a mixed configuration, and the electrical load 410 is electrically connected to the energy storage device 300. The battery device 200 of the energy storage device 300 is used to store electrical energy, or the battery device 200 of the energy storage device 300 is used to provide electrical energy to the electrical load 410, thereby enabling the electrical load 410 to operate normally.

[0095] Alternatively, in some other embodiments of this application, the electrical device 400 further includes a battery device 200 as described above. That is, the electrical device 400 uses one battery device 200 or multiple battery devices 200 connected in series, parallel, or mixed connection, and the electrical load 410 is electrically connected to the battery device 200. The battery device 200 is used to store electrical energy, or the battery device 200 is used to provide electrical energy to the electrical load 410, thereby enabling the electrical load 410 to operate normally.

[0096] 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.

[0097] Among them, the electrical equipment 400 is an electric vehicle, and it is assembled using a battery device 200, such as Figure 15 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.

[0098] 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 by, The battery cell comprises: a housing formed with a receiving space and an open end communicating with the receiving space; an electrode assembly installed in the receiving space, the electrode assembly comprising an anode sheet and a cathode sheet, the anode sheet and the cathode sheet being stacked and insulated; an end cover covering the open end, the end cover comprising an insulating inner cover, the insulating inner cover comprising a body portion and a protruding structure connected to the body portion, the protruding structure being located on a side of the body portion facing the receiving space and being arranged in a circumferential direction, an end plane being formed at an end of the protruding structure away from the body portion, the end plane abutting an edge region of one end of the electrode assembly, and a cross-sectional width of the end plane being greater than a thickness of the anode sheet or the cathode sheet.

2. The battery cell according to claim 1, wherein a glue layer is provided between the end plane and the electrode assembly, a width of the glue layer being greater than the thickness of the anode sheet or the cathode sheet.

3. The battery cell according to claim 2, wherein the width of the glue layer is greater than or equal to the cross-sectional width of the end plane.

4. The battery cell according to claim 1, wherein the end plane is perpendicular to an arrangement direction of the end cover and the electrode assembly.

5. The battery cell according to any one of claims 1-4, wherein a cross-section of the protruding structure is a trapezoid gradually expanding from the body portion to the electrode assembly.

6. The battery cell according to claim 5, wherein the protruding structure is a circumferentially continuous integral structure; or the protruding structure comprises a plurality of protruding blocks arranged at intervals in the circumferential direction.

7. The battery cell according to claim 6, wherein the body portion and the protruding structure are integrally formed.

8. The battery cell according to claim 7, wherein the electrode assembly is a stacked sheet structure or a wound structure; and the receiving space is a square space.

9. The battery cell according to claim 7, wherein the anode sheet is provided with a negative electrode tab, the cathode sheet is provided with a positive electrode tab, an end of the housing opposite to the open end is a closed end, the positive electrode tab and the negative electrode tab are both located at one end of the electrode assembly facing the open end, and the positive electrode tab and the negative electrode tab are both provided through the body portion.

10. The battery cell according to claim 7, wherein the anode sheet is provided with a negative electrode tab, the cathode sheet is provided with a positive electrode tab, the open end comprises a first open end and a second open end, the first open end and the second open end are respectively located at opposite ends of the housing, the battery cell comprises a first end cover and a second end cover, the first end cover and the second end cover cover the first open end and the second open end respectively, one of the positive electrode tab and the negative electrode tab is located at one end of the electrode assembly facing the first open end and is provided through the body portion of the first end cover, and the other of the positive electrode tab and the negative electrode tab is located at one end of the electrode assembly facing the second open end and is provided through the body portion of the second end cover. ​ 11. A battery device characterized by comprising: The battery cell as claimed in any one of claims 1-10 is used for storing or providing electric energy.

12. An energy storage device, characterized in that, The energy storage device comprises the battery cell as claimed in any one of claims 1-10, which is used for storing or providing electric energy. Or, the energy storage device comprises the battery device as claimed in claim 11, which is used for storing or providing electric energy.

13. An electrical device, characterized by The electric load comprises a plurality of battery cells as claimed in any one of claims 1-10, and the electric load is electrically connected to the plurality of battery cells. Or, the electric load comprises the battery device as claimed in claim 11, and the electric load is electrically connected to the battery device. Or, the electric load comprises the energy storage device as claimed in claim 12, and the electric load is electrically connected to the energy storage device. The battery cell is used for storing or providing electric energy. ​

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