Battery cell, method for manufacturing battery cell, battery, and electric device

Abstract

The application discloses a battery monomer, a preparation method of the battery monomer, a battery and an electric device. The battery monomer comprises a pole shell, a pole column and a cover plate. The pole shell comprises a first wall. The pole column is arranged on the first wall and has a through hole. The cover plate is arranged on one side of the pole column and covers one end of the through hole. The electrode assembly comprises an active material coating part and a conductive part connected with the active material coating part. The active material coating part is arranged in the shell. At least part of the conductive part is arranged in the through hole and connected with the cover plate. According to the battery monomer, at least part of the conductive part is arranged in the through hole, so that the occupied space of the conductive part in the shell can be reduced, the weight of the pole column can be reduced, the volume energy density and the weight energy density of the battery monomer can be improved, the redundancy of the conductive part in the shell can be reduced, the short-circuit probability of the battery monomer can be reduced, and the reliability of the battery can be improved.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a battery cell, a method for preparing the battery cell, a battery, and an electrical device thereof. Background Technology

[0002] With increasingly severe environmental problems, growing public awareness of environmental protection, and rising oil prices, more and more people are focusing on new energy vehicles when purchasing vehicles. The range and power performance of these vehicles significantly influence consumer choices. Currently, most new energy vehicles use power batteries as energy storage and power sources, and they are also found in other types of vehicles. The energy density of the power battery has a significant impact on the vehicle's range and power performance; therefore, improving battery energy density is a continuous research focus in the ongoing improvement and innovation of batteries.

[0003] Currently, the energy density of batteries still needs to be improved. Summary of the Invention

[0004] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a battery cell that can improve the volumetric energy density and gravimetric energy density of the battery cell, reduce the probability of short circuits, and improve the operational reliability and stability of the battery cell and the battery.

[0005] The present invention also proposes a method for preparing a single battery cell.

[0006] The present invention also proposes a battery having the above-mentioned battery cells.

[0007] The present invention also proposes an electrical device having the above-mentioned battery.

[0008] According to a first aspect of the present invention, a battery cell includes: a housing including a first wall; an electrode post disposed on the first wall and having a through hole; a cover plate disposed on one side of the electrode post and covering one end corresponding to the through hole; and an electrode assembly including an active material coating portion and a conductive portion connected to the active material coating portion, wherein the active material coating portion is disposed within the housing, and at least a portion of the conductive portion is disposed within the through hole and connected to the cover plate.

[0009] According to the battery cell of the present invention, by providing a through hole in the terminal post and having at least a portion of the conductive part disposed within the through hole, the space occupied by the conductive part inside the casing can be reduced, allowing the housing cavity of the casing to accommodate a larger active material coating portion. This improves the volumetric energy density of the battery cell. Simultaneously, it reduces the redundancy of the conductive part within the casing, lowers the probability of short circuits between the conductive part and the active material coating portion, reduces the probability of short circuits in the battery cell, and improves the operational reliability and stability of the battery cell and the battery. Furthermore, by providing a through hole inside the terminal post, the weight of the terminal post can be reduced, thereby increasing the gravimetric energy density of the battery cell and the battery.

[0010] In some embodiments, the cover plate is welded to the conductive part.

[0011] This embodiment increases the connection strength and stability between the cover plate and the conductive part by welding them together, thereby improving the stability of the electrical connection between the conductive part and the terminal post. At the same time, it can also reduce the connection complexity between the cover plate and the conductive part, thereby reducing the production cost and overall weight of the battery cell.

[0012] In some embodiments, the cover plate has a first welding area and a second welding area, the first welding area being welded to the conductive part, the second welding area being used for welding and connecting electrical connecting pieces, and the first welding area and the second welding area being different areas of the cover plate.

[0013] This embodiment, by setting a first welding area and a second welding area, can define the welding positions of the conductive part and the electrical connecting piece respectively, thereby increasing the convenience and reliability of battery cell assembly. At the same time, by setting the first welding area and the second welding area as different areas of the cover plate, it can also effectively prevent the problem of welding quality degradation caused by the connection of the two welding pools, thereby improving the welding quality of the conductive part and the electrical connecting piece to the cover plate, and thus improving the electrical connection stability of the battery cell.

[0014] In some embodiments, the first welding area and the second welding area are respectively formed on both sides of the center line of the cover plate perpendicular to the length direction or the width direction.

[0015] In this embodiment, by setting the first welding area and the second welding area to be formed on both sides of the center line perpendicular to the length or width direction of the cover plate, the positions of the first welding area and the second welding area can be further defined, thereby increasing the convenience and reliability of battery cell assembly.

[0016] In some embodiments, the distance between the first welding area and the second welding area is less than or equal to two-thirds of the width of the cover plate, and / or the distance between the first welding area and the second welding area is greater than or equal to one-third of the width of the cover plate.

[0017] This embodiment sets the distance between the first welding area and the second welding area to be less than or equal to two-thirds of the width of the cover plate. This prevents the distance between the first welding area and the second welding area from being too large, which helps to ensure the welding area of ​​the first welding area and the second welding area on the cover plate. This facilitates the connection between the conductive part and the electrical connecting piece and the cover plate, ensuring the welding quality of the conductive part and the electrical connecting piece and the cover plate, thereby improving the electrical connection stability of the battery cell. At the same time, by setting the distance between the first welding area and the second welding area to be greater than or equal to one-third of the width of the cover plate, this prevents the distance between the first welding area and the second welding area from being too small. This effectively prevents the problem of reduced welding quality caused by the connection of the two weld pools, thereby improving the welding quality of the conductive part and the electrical connecting piece and the cover plate, and thus improving the electrical connection stability of the battery cell.

[0018] In some embodiments, the distance between the first welding area and the second welding area is greater than or equal to 2 mm.

[0019] This embodiment, by setting the distance between the first welding area and the second welding area to be greater than or equal to 2mm, can effectively prevent the problem of reduced welding quality caused by the connection of the two welding pools, thereby improving the welding quality of the conductive part and the electrical connection piece to the cover plate, and thus improving the electrical connection stability of the battery cell.

[0020] In some embodiments, the first welding area is welded to the conductive part to form a first weld pool, and the second welding area is welded to the electrical connector to form a second weld pool, with the first weld pool and the second weld pool being spaced apart.

[0021] This embodiment effectively solves the problem of the first and second welding pools being connected by setting the first welding pool and the second welding pool separately, thereby improving the welding quality of the conductive part and the electrical connection piece to the cover plate, and thus improving the electrical connection stability of the battery cell.

[0022] In some embodiments, the ratio of the thickness of the cover plate to the thickness of the first wall is 1-4; optionally, the ratio of the thickness of the cover plate to the thickness of the first wall is 2-3; optionally, the thickness of the cover plate is greater than or equal to 1.5 mm and less than or equal to 5 mm.

[0023] In this embodiment, by setting the ratio of the thickness of the cover plate to the thickness of the first wall to be 1-4, the thickness of the cover plate can meet the welding requirements of the conductive part and the electrical connection piece, while also ensuring that the thickness of the cover plate is not too thick, which is beneficial to the lightweighting of the battery cell.

[0024] In this embodiment, by setting the ratio of the thickness of the cover plate to the thickness of the first wall to 2-3, the thickness of the cover plate can be further limited, so that the thickness of the cover plate is not too large, which is beneficial to the lightweighting of the battery cell; at the same time, it also ensures that the thickness of the cover plate is not too small, so that it can meet the welding requirements of the conductive part and the electrical connection piece, as well as the structural strength requirements of the battery cell.

[0025] In this embodiment, by setting the thickness of the cover plate to be greater than or equal to 1.5 mm and less than or equal to 5 mm, the thickness of the cover plate can meet the welding requirements of the conductive part and the electrical connection piece, while also controlling the thickness of the cover plate to prevent it from being too large. This reduces the space occupied by the cover plate in the through hole, thereby improving the space utilization rate of the battery cell.

[0026] In some embodiments, the cover plate includes a cover plate body and a boss. The cover plate body covers one end of the through hole, the boss is disposed on the side surface of the cover plate body facing the electrode assembly and extends into the through hole, and the conductive part is connected to the boss.

[0027] This embodiment, by setting the cover plate body and the boss, can increase the sealing effect between the cover plate and the electrode post, further reduce the risk of electrolyte leakage from the through hole, and improve the reliability of the battery cell; at the same time, it can further reduce the occurrence of weld pool connection during the welding process, thereby further improving the welding quality of the conductive part and electrical connection piece to the cover plate, and thus improving the electrical connection stability of the battery cell.

[0028] In some embodiments, the height of the boss protruding from the side surface of the cover plate body is 1mm-5mm; optionally, 1.5mm-3mm.

[0029] In this embodiment, by setting the height of the boss protruding from one side surface of the cover plate body to 1mm-5mm, the thickness of the boss is not too large, which helps to reduce the space occupied by the cover plate in the through hole, thereby improving the space utilization of the battery cell; it also ensures that the thickness of the boss is not too small, so that the thickness of the boss meets the welding requirements of the conductive part, thereby increasing the connection stability between the conductive part and the boss.

[0030] In this embodiment, by setting the height of the boss protruding from one side surface of the cover plate body to 1.5mm-3mm, the thickness of the boss can meet the welding requirements of the conductive part, while further reducing the space occupied by the cover plate in the through hole, thereby further improving the space utilization rate of the battery cell.

[0031] In some embodiments, the boss is clearance-fitted with one end of the through hole, and the clearance between the boss and the through hole is 0-0.1 mm.

[0032] In this embodiment, by setting a clearance fit between the boss and one end of the through hole, and the clearance between the boss and the through hole is 0-0.1mm, it is beneficial for the boss to enter and exit the through hole, thereby reducing the assembly difficulty of the cover plate and the pole post.

[0033] In some embodiments, the clearance between the boss and the through hole is less than or equal to 0.05 mm.

[0034] In this embodiment, by setting the fit clearance between the boss and the through hole to be less than or equal to 0.05 mm, the gap between the boss and the inner wall of the through hole can be further reduced, thereby further improving the blocking effect of the boss on the through hole, reducing the risk of electrolyte leakage from the cover plate, and thus improving the reliability of the battery cell.

[0035] In some embodiments, the electrode post is a negative electrode post, the cover plate body and the boss are separate parts, the cover plate body and the boss are made of different materials, the boss is made of the same material as the conductive part, and when the boss is welded to the conductive part, the depth of the molten pool on the cover plate is less than the thickness of the boss.

[0036] In this embodiment, by using the negative electrode post and setting the cover plate body and the boss as separate components, and making the material of the boss the same as that of the conductive part, the material of the boss and the conductive part can be matched, thereby increasing the welding quality of the boss and the conductive part and increasing the connection stability of the boss and the conductive part. In addition, when welding the boss and the conductive part, the depth of the molten pool on the cover plate is less than the thickness of the boss, and the welding position is controlled between the same material, which can further increase the welding quality of the boss and the conductive part and reduce the welding difficulty of the boss and the conductive part.

[0037] In some embodiments, the electrode post is a positive electrode post, the boss and the cover plate body are integrally formed, and when the cover plate is welded to the conductive part, the depth of the molten pool on the boss is greater than the thickness of the boss.

[0038] In this embodiment, when the electrode is a positive electrode, the boss is integrally formed with the cover plate body. This allows the cover plate to meet the welding requirements with the electrical connection piece and conductive part, while also reducing the production process and steps of the cover plate, thereby increasing the production rate and reducing the production cost of the cover plate.

[0039] In some embodiments, the pole is welded to the cover plate.

[0040] This embodiment increases the connection stability and sealing of the terminal post and the cover plate by welding them together, thereby improving the gas seal of the battery cell and thus improving the reliability of the battery cell.

[0041] In some embodiments, the pole post is a hollow annular structure with the through hole defined on its inner side.

[0042] This embodiment, by setting the electrode post as a hollow ring and defining a through hole on the inner side, can reduce the weight of the electrode post to a certain extent, thereby increasing the weight energy density of the battery cell and the battery. At the same time, the hollow ring has a large internal cavity volume, which makes it easy for the conductive part to extend out of the through hole, thereby reducing the welding difficulty of the conductive part to the cover plate, reducing the assembly difficulty of the battery cell, and increasing the assembly rate of the battery cell.

[0043] In some embodiments, the electrode post includes: an electrode post body, the electrode post body being annular and defining the through hole on its inner side; a first ring, the first ring being connected to one end of the electrode post body facing the electrode assembly, the first ring extending radially outward along the electrode post body and extending circumferentially along the electrode post body to form an annular shape; and a second ring, the second ring being connected to the other end of the electrode post body opposite to the electrode assembly, the second ring extending radially outward along the electrode post body and extending circumferentially along the electrode post body to form an annular shape.

[0044] This embodiment features a first ring and a second ring at each end of the electrode post body. These rings enhance the structural strength of the electrode post body, improving overall structural strength and making the connection between the electrode post and the tab more stable and reliable. This allows the electrode post to better participate in the energy transfer process within the battery cell. The first and second rings also cooperate with the electrode post body to form a slot structure, facilitating the installation and fixation of the electrode post within the battery cell. The first and second rings are simple in structure and easy to use.

[0045] In some embodiments, a groove is formed on the side surface of the electrode post facing away from the electrode assembly, a through hole is formed inside the groove and penetrates the bottom wall of the groove, and a cover plate is disposed in the groove.

[0046] In this embodiment, a groove is formed on the side surface of the pole away from the electrode assembly, which makes it easier to position the cover plate and pole when they are fixed, and the connection and fixation are more stable and reliable.

[0047] In some embodiments, in the direction from the electrode assembly toward the cover plate, the sidewalls of the groove extend radially outward along the through hole.

[0048] This embodiment, by setting the sidewall of the groove to extend radially outward along the through hole, can provide a certain guiding effect during the assembly of the cover plate and the terminal post, making it easier to fix the cover plate in the groove. The structure is simple and easy to assemble. At the same time, when the cover plate and the terminal post are welded together, the periphery of the cover plate and the inclined sidewall of the groove can increase the welding width, resulting in higher welding quality between the cover plate and the terminal post. This, in turn, can improve the welding sealing effect between the cover plate and the terminal post, and increase the sealing performance of the battery cell.

[0049] In some embodiments, the side surface of the cover plate facing away from the electrode assembly is flush with the end face of the pole facing away from the electrode assembly.

[0050] In this embodiment, by setting one side surface of the cover plate away from the electrode assembly to be flush with one end face of the pole piece away from the electrode assembly, the cover plate and the pole piece can form a continuous plane. This can reduce the space occupied by the cover plate to a certain extent and increase the electrical connection surface of the battery cell pole piece, thereby improving the energy density of the battery cell. It also allows the battery cell to be more easily electrically connected to the electrical connector through one end of the pole piece away from the electrode assembly. At the same time, it can also improve the appearance of the battery cell.

[0051] In some embodiments, the active material coating portion includes a current collector and an active material layer disposed on the current collector, the conductive portion includes an electrode portion electrically connected to the current collector, the electrode portion includes a plurality of electrode tabs, the plurality of electrode tabs converge at a position close to the current collector to form a first convergence portion, the plurality of electrode tabs converge at a position away from the current collector and connect to form a second convergence portion, the first convergence portion connects the second convergence portion and the active material coating portion, and at least a portion of the second convergence portion is accommodated within the through hole.

[0052] This embodiment uses multiple tabs that converge to form a second converged portion, allowing the second converged portion to have a smaller size and thickness. This makes it easier for the tabs to extend into the through hole and connect to the cover plate, thereby increasing the convenience of connecting the conductive part to the cover plate. Simultaneously, it effectively reduces the risk of short circuits between the tabs and the active material coating below the tabs due to tab branching, thus improving the reliability of the battery cell. Furthermore, since at least a portion of the second converged portion is housed within the through hole, it fully utilizes the space of the terminal post, increasing the volumetric energy density of the battery cell.

[0053] In some embodiments, the conductive portion is fixedly connected to the cover plate via the second folding portion.

[0054] This embodiment simplifies the composition of battery cells, reduces the number of components, simplifies the assembly process, and improves assembly efficiency by setting the conductive part to be fixedly connected to the cover plate through the second gathering part.

[0055] In some embodiments, at least a portion of the first gathering portion is accommodated within the through hole.

[0056] This embodiment, by setting at least a portion of the first gathering part to be accommodated in the through hole, can make fuller use of the space inside the electrode post, further reduce the space occupied by the electrode tab in the housing, so as to accommodate a larger active material coating part, improve the volumetric energy density of the battery cell, and can better reduce the redundancy of the electrode tab in the housing, further reducing the probability of short circuit between the electrode tab and the active material coating part.

[0057] In some embodiments, the active material coating portion includes a current collector and an active material layer disposed on the current collector. The conductive portion includes an electrode portion electrically connected to the current collector. The electrode portion includes a plurality of electrode tabs. The plurality of electrode tabs converge near the current collector to form a first convergence portion, and the plurality of electrode tabs converge and connect away from the current collector to form a second convergence portion. The first convergence portion connects the second convergence portion and the active material coating portion. The conductive portion further includes an adapter piece. The adapter piece is connected to the second convergence portion. The conductive portion is electrically connected to the cover plate through the adapter piece. At least a portion of the adapter piece is accommodated within the through hole.

[0058] This embodiment, by providing an adapter plate, allows at least a portion of the second convergent portion and at least a portion of the adapter plate to be accommodated within the through hole. This enables more efficient use of the space within the terminal post, further reducing the space occupied by the conductive parts within the casing and thus increasing the volumetric energy density of the battery cell. Simultaneously, the adapter plate avoids welding the second convergent portion to the terminal post, resulting in a more robust weld between the adapter plate and the terminal post, reducing the risk of weld cracking, and further improving the reliability and stability of the battery cell. Furthermore, the electrical connection between the terminal post and the tab via the adapter plate simplifies the construction of the tab.

[0059] In some embodiments, at least a portion of the second gathering portion is located within the through hole; or, the entire second gathering portion is located within the through hole, and at least a portion of the first gathering portion is located within the through hole.

[0060] This embodiment, by setting at least a portion of the second gathering part to be located within the through hole, can fully utilize the space within the electrode post, further reducing the space occupied by the tab within the casing, thereby improving the volumetric energy density of the battery cell. By setting the entire second gathering part to be located within the through hole, and at least a portion of the first gathering part to be located within the through hole, the space within the electrode post can be utilized even more fully, significantly reducing the space occupied by the tab within the casing, and thus significantly improving the volumetric energy density of the battery cell. At the same time, it can further reduce the redundancy of the tab within the casing, further reducing the probability of short circuit between the tab and the active material coating.

[0061] In some embodiments, the second gathering portion extends along the surface of the cover plate, and in the direction from the electrode assembly toward the cover plate, one end of the first gathering portion is connected to the active material coating portion, and the other end of the first gathering portion extends obliquely toward the peripheral wall of the through hole and extends to be connected to one end of the second gathering portion.

[0062] In this embodiment, by setting a second gathering portion extending along the surface of the cover plate, one end of the first gathering portion is connected to the active material coating portion in the direction from the electrode assembly toward the cover plate, and the other end of the first gathering portion extends obliquely toward the peripheral wall of the through hole and extends to connect with one end of the second gathering portion. This can increase the length of the first gathering portion inside the through hole, thereby effectively reducing the space ratio of the tab inside the battery cell, thus accommodating a larger active material coating portion, improving the volumetric energy density of the battery cell, and better reducing the redundancy of the tab portion in the casing, further reducing the probability of short circuit between the tab portion and the active material coating portion, and increasing the stability of the battery cell.

[0063] According to a method for preparing a battery cell according to a second aspect of the present invention, the method includes: passing one end of a conductive portion through a through hole in an electrode post and extending it from the other side of the electrode post; welding the one end of the conductive portion to a cover plate on the other side of the electrode post; covering one end of the through hole with the cover plate and housing the conductive portion within the through hole; and fixing the cover plate to the electrode post.

[0064] According to the method for preparing a battery cell of the present invention, the cover plate and the conductive part can be welded together on the outside of the battery cell. This reduces the damage to the battery cell caused by welding slag falling into the battery cell during the welding process, thereby improving the reliability of the battery cell. At the same time, the conductive part can be housed in the through hole, which reduces the space occupied by the conductive part inside the casing, allowing the casing to accommodate a larger volume of active material coating part, thereby increasing the energy density of the battery cell. In addition, the redundancy of the conductive part can be reduced, further reducing the probability of short circuit between the conductive part and the active material coating part, and increasing the stability of the battery cell.

[0065] In some embodiments, welding one end of the conductive portion to the cover plate on the other side of the pole post includes: pressing the other end of the conductive portion onto one side surface of the cover plate; and laser welding the other end of the conductive portion to the cover plate.

[0066] In this embodiment, by pressing the other end of the conductive part onto one side surface of the cover plate, the welding gap can be ensured to achieve laser welding and improve welding quality. By using laser welding to connect the conductive part and the cover plate, the connection speed between the conductive part and the cover plate can be increased, and the welding quality between the conductive part and the cover plate can be improved.

[0067] The battery according to the third aspect of the present invention comprises a battery cell according to the first aspect of the present invention; or, comprises a battery cell prepared by the method for preparing a battery cell according to the second aspect of the present invention.

[0068] According to the battery of the present invention, the overall performance of the battery is improved by using the battery cell of the first aspect described above or by the battery cell prepared by the method of the battery cell of the second aspect described above.

[0069] An electrical appliance according to a fourth aspect of the invention includes a battery according to a third aspect of the invention, said battery being used to provide electrical energy.

[0070] According to the present invention, by providing the battery described in the third aspect, the overall performance of the electrical device is improved.

[0071] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0072] Figure 1 This is a schematic diagram of a vehicle according to an embodiment of the present invention;

[0073] Figure 2 This is an exploded view of a battery according to an embodiment of the present invention;

[0074] Figure 3 This is a partial schematic diagram of a battery cell according to an embodiment of the present invention;

[0075] Figure 4 This is a partial schematic diagram of another state of a battery cell according to an embodiment of the present invention, wherein the battery cell has been assembled.

[0076] Figure 5 This is a partial schematic diagram of another state of a battery cell according to an embodiment of the present invention, wherein the cover plate seals the through hole;

[0077] Figure 6 yes Figure 5 A schematic diagram of the cover plate shown;

[0078] Figure 7 yes Figure 5 A schematic diagram of the pole shown;

[0079] Figure 8 yes Figure 5 A schematic diagram of another angle of the pole shown;

[0080] Figure 9 yes Figure 5 A schematic diagram of another angle of the pole shown;

[0081] Figure 10 yes Figure 5 A schematic diagram of another angle of the pole shown;

[0082] Figure 11 This is an assembly diagram of a battery cell according to an embodiment of the present invention;

[0083] Figure 12 This is an assembly diagram of another state of a battery cell according to an embodiment of the present invention, wherein one end of the conductive part extends out of the through hole;

[0084] Figure 13 This is an assembly diagram of a battery cell in another state according to an embodiment of the present invention, wherein the conductive part is laser welded to the cover plate.

[0085] Figure 14 yes Figure 3 A schematic diagram of the electrode assembly shown.

[0086] Figure label:

[0087] 1. Vehicles;

[0088] 1000, battery;

[0089] 100. Battery cell;

[0090] 10. Shell; 11. First wall;

[0091] 20. Pole post; 21. Pole post body; 211. Through hole; 212. Groove; 22. First ring; 23. Second ring;

[0092] 30. Electrode assembly; 31. Active material coating part; 32. Conductive part; 321. Electrode tab part; 3211. First gathering part; 3212. Second gathering part;

[0093] 40. Cover plate; 41. Cover plate body; 42. Boss; 43. First welding zone; 431. First weld pool; 44. Second welding zone; 441. Second weld pool;

[0094] 50. Electrical connector;

[0095] 200. Container body; 201. Main container; 202. End cap;

[0096] 2000, controller; 3000, motor. Detailed Implementation

[0097] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention.

[0098] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the invention, are intended to cover non-exclusive inclusion.

[0099] In the description of the embodiments of this invention, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this invention, "multiple" means two or more, unless otherwise explicitly defined.

[0100] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0101] In the description of the embodiments of this invention, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0102] In the description of embodiments of the present invention, the term "multiple" refers to two or more (including two).

[0103] In the description of the embodiments of the present invention, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention.

[0104] In the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention according to the specific circumstances.

[0105] Currently, judging from market trends, the application of power batteries is becoming increasingly widespread. Power batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of power battery applications, market demand is also constantly increasing.

[0106] In related technologies, battery cells are manufactured by coating an active material layer onto a current collector and then cutting it to obtain an electrode assembly consisting of a current collector coated with the active material layer (referred to as the active material coated portion) and a current collector without the active material layer (referred to as the tab). The positive and negative electrode assemblies and a separator are then sequentially stacked or wound to obtain an electrode assembly. Multiple tabs are stacked in the electrode assembly to form a tab portion. The battery cell casing has a terminal post, and the surface of the terminal post facing the active material coated portion is the inner end face of the terminal post. During battery cell manufacturing, the tab portion is typically directly welded to the inner end face of the terminal post, or indirectly welded to the inner end face of the terminal post via an adapter plate, to ensure normal charging and discharging operations.

[0107] However, when the battery cell adopts the above structure, the tabs and adapter plates are both piled up between the active material coating and the inner end face of the terminal post, occupying a large space. This means that with a fixed casing size, the size of the active material coating cannot be increased, making it difficult to improve the energy density of the battery cell. Moreover, due to design or manufacturing reasons, the length of the tabs is usually relatively long. When the space between the active material coating and the inner end face of the terminal post is small, there is a problem of tab redundancy after the electrode assembly is installed in the casing. This can easily lead to short circuits between the tabs or adapter plates and the active material coating, affecting the reliability and stability of the battery cell.

[0108] Based on the above considerations, in order to reduce the space occupied by the tabs and improve the energy density of the battery cell, the present invention provides a battery cell with a through hole inside the terminal post, and at least part of the conductive part is disposed in the through hole. This reduces the space occupied by this part in the housing, thereby saving more space in the housing to accommodate the active material coating part. This allows the volume of the active material coating part to be increased, which in turn helps to improve the energy density of the battery cell. Moreover, it can reduce the redundancy of the tabs or adapters in the housing, reduce the probability of short circuit between the tabs or adapters and the active material coating part, thereby reducing the probability of reliability-related problems caused by short circuits and improving the working reliability and stability of the battery cell and the battery.

[0109] The battery cells disclosed in this application can be used in electrical devices that use batteries as a power source or in various energy storage systems that use batteries as energy storage elements. Electrical devices can be, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0110] For ease of explanation, the following embodiments will be described using a vehicle 1 as an example of an electrical device according to an embodiment of the present invention.

[0111] Reference Figure 1 , Figure 1This is a schematic diagram of a vehicle 1 provided in some embodiments of the present invention. Vehicle 1 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, or a range-extended electric vehicle, etc. A battery 1000 is installed inside vehicle 1, and the battery 1000 can be located at the bottom, front, or rear of vehicle 1. The battery 1000 can be used to power vehicle 1; for example, the battery 1000 can serve as the operating power source for vehicle 1. Vehicle 1 may also include a controller 2000 and a motor 3000. The controller 2000 is used to control the battery 1000 to supply power to the motor 3000, for example, to meet the power needs of vehicle 1 during starting, navigation, and driving.

[0112] In some embodiments of this application, the battery 1000 can not only serve as the operating power source for the vehicle 1, but also as the driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0113] Reference Figure 2 , Figure 2 This is an exploded view of a battery 1000 according to some embodiments of the present invention. The battery 1000 includes a housing 200 and a battery cell 100. The housing 200 has a cavity, and the battery cell 100 is housed within the cavity of the housing 200. The housing 200 provides a receiving space for the battery cell 100, and the housing 200 can adopt various structures. In some embodiments, the housing 200 may include a first part (e.g., a main housing 201 as described below) and a second part (e.g., an end cap 202 as described below), the first part and the second part overlapping each other, and the first part and the second part together defining a receiving space for accommodating the battery cell 100. The second part may be a hollow structure with one open end, and the first part may be a plate-like structure, with the first part covering the open side of the second part so that the first part and the second part together define the receiving space; the first part and the second part may also both be hollow structures with one open side, with the open side of the first part covering the open side of the second part. Of course, the housing 200 formed by the first part and the second part can be of various shapes, such as a cylinder, a cuboid, etc.

[0114] In battery 1000, there can be multiple battery cells 100, which can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 100 are connected in both series and parallel configurations. Multiple battery cells 100 can be directly connected in series, parallel, or in a mixed manner, and then the entire assembly of the multiple battery cells 100 is housed within housing 200. Alternatively, battery 1000 can also consist of multiple battery cells 100 first connected in series, parallel, or in a mixed manner to form a battery module, and then multiple battery modules are connected in series, parallel, or in a mixed manner to form a whole, which is also housed within housing 200. Battery 1000 may also include other structures; for example, it may include a busbar component for electrical connection between multiple battery cells 100.

[0115] Each battery cell 100 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited to these. The battery cell 100 can be cylindrical, flat, cuboid, or other shapes.

[0116] The following is for reference. Figures 3-14 A battery cell 100 according to an embodiment of the first aspect of the present invention is described. Figure 3 This is a partial schematic diagram of a battery cell 100 according to some embodiments of the present invention. Figure 4 This is a partial schematic diagram of another state of the battery cell 100 according to some embodiments of the present invention, wherein the battery cell 100 is assembled. Figure 5 This is a partial schematic diagram of another state of a battery cell 100 according to some embodiments of the present invention, wherein the cover plate 40 covers the through hole 211. Figure 6 yes Figure 5 A schematic diagram of the cover plate 40 shown. Figure 7 yes Figure 5 A schematic diagram of the pole post 20 shown. Figure 8 yes Figure 5 A schematic diagram of another angle of the pole post 20 shown. Figure 9 yes Figure 5 A schematic diagram of another angle of the pole post 20 shown. Figure 10 yes Figure 5 A schematic diagram of another angle of the pole post 20 shown. Figure 11 This is an assembly schematic diagram of a battery cell 100 according to some embodiments of the present invention. Figure 12 This is an assembly schematic diagram of another state of the battery cell 100 according to some embodiments of the present invention, wherein one end of the conductive part 32 extends out of the through hole 211. Figure 13 This is a schematic diagram of the assembly of a battery cell 100 in another state according to some embodiments of the present invention, wherein the conductive part 32 is laser welded to the cover plate 40. Figure 14 yes Figure 3 A schematic diagram of the electrode assembly 30 shown.

[0117] This invention provides a battery cell 100, such as... Figure 3 As shown, the battery cell 100 includes: a housing 10, a terminal post 20, a cover plate 40, and an electrode assembly 30. Specifically, the housing 10 includes a first wall 11; the terminal post 20 is disposed on the first wall 11 and has a through hole 211; the cover plate 40 is disposed on one side of the terminal post 20 and covers one end corresponding to the through hole 211; the electrode assembly 30 includes an active material coating portion 31 and a conductive portion 32 connected to the active material coating portion 31. The active material coating portion 31 is disposed inside the housing 10, and at least a portion of the conductive portion 32 is disposed inside the through hole 211 and connected to the cover plate 40.

[0118] The shape of the casing 10 can be adjusted according to the type of battery cell 100. For example, when the battery cell 100 is a square battery 1000, the casing 10 is square; when the battery cell 100 is a cylindrical battery 1000, the casing 10 is cylindrical. In the embodiments of the present invention, a square casing 10 is used as an example for illustration. (Reference) Figure 3 As shown, the housing 10 can be an aluminum housing, a stainless steel housing, etc. The housing 10 is used to house the electrode assembly 30 in the battery cell 100 and to fix the terminal post 20. The first wall 11 of the housing 10 is formed in the length direction of the housing 10 (e.g., Figure 3 At one end (shown in the up-down direction), during the assembly of the battery cell 100, the electrode assembly 30 can be placed into the receiving cavity of the housing 10, and the electrode post 20 is fixed to the first wall 11 of the housing 10. Specifically, the first wall 11 of the housing 10 may be provided along the thickness direction of the first wall 11 (e.g., in the up-down direction). Figure 3 The mounting hole (shown in the up-down direction) passes through the first wall 11. The pole post 20 is set in the mounting hole and fixedly connected to the housing 10. For example, the pole post 20 and the housing 10 can be welded or riveted to fix them.

[0119] The terminal post 20 is used to connect the battery cell 100 to the electrical connector and transmit electrical energy. The material of the terminal post 20 can be copper, aluminum, zinc, or their alloys, etc. The shape of the terminal post 20 can be set to a circular, rectangular, or other shape structure according to design requirements. Generally, there are at least two terminal posts 20. Specifically, there is at least one positive terminal post and at least one negative terminal post. For example, when there are two terminal posts 20, one is a positive terminal post and the other is a negative terminal post, and the two are electrically connected to the positive and negative tabs of the electrode assembly 30, respectively. As another example, when there are four terminal posts 20, there can be two positive terminal posts and two negative terminal posts. In this case, both positive terminal posts are electrically connected to the positive tabs of the electrode assembly 30, and both negative terminal posts are electrically connected to the negative tabs of the electrode assembly 30.

[0120] The cover plate 40 is sealed to the terminal post 20 to seal the through hole 211, thereby sealing the battery cell 100 and isolating it from the outside environment, thus improving its reliability. Simultaneously, the conductive part 32 is electrically connected to the cover plate 40, and the cover plate 40 is connected to the terminal post 20, enabling the electrical transmission of power from the battery cell 100. Optionally, the cover plate 40 can be made of the same material as the terminal post 20, and its shape can be designed according to the shape of the through hole 211.

[0121] The electrode assembly 30 is typically formed by stacking or winding electrode sheets and separators. The electrode sheets include positive electrode sheets and negative electrode sheets. The positive electrode tabs led out from the positive electrode sheets are electrically connected to the positive electrode post 20, and the negative electrode tabs led out from the negative electrode sheets are electrically connected to the negative electrode post 20.

[0122] The active material coating part 31 is the part of the electrode assembly 30 coated with active material, which can assist in the deintercalation and deintercalation of metal ions during the charging and discharging process of the battery cell 100. The conductive part 32 is a metal structure that electrically connects the active material coating part 31 and the terminal 20. It is not coated with active material, and both the positive terminal and the negative terminal can be electrically connected to the active material coating part 31 through the conductive part 32 so that the charging and discharging operation of the battery cell 100 can be carried out.

[0123] It should be noted that, in the embodiments of this application, the active material coating portion 31 is divided into a positive electrode active material coating portion and a negative electrode active material coating portion. The positive electrode active material coating portion includes the portion of the positive electrode current collector coated with a positive electrode active material layer, and the negative electrode active material coating portion includes the portion of the negative electrode current collector coated with a negative electrode active material layer. The conductive portion 32 is divided into a positive electrode conductive portion and a negative electrode conductive portion. The positive electrode conductive portion is electrically connected to the positive electrode active material coating portion and the positive electrode post, and the negative electrode conductive portion is electrically connected to the negative electrode active material coating portion and the negative electrode post.

[0124] For ease of description, the embodiments of the present invention will not distinguish between the positive and negative electrodes, such as the electrode post 20, the conductive part 32, and the active material coating part 31. The electrode post 20, the conductive part 32, and the active material coating part 31, and their related descriptions involved in the embodiments of the present invention can be applied to structures such as positive electrode post, negative electrode post, positive active material coating part, negative active material coating part, positive conductive part, and negative conductive part.

[0125] In this embodiment, the electrode post 20 has a through hole 211, which extends through the electrode assembly 30 toward the cover plate 40, thus forming a hollow structure inside the electrode post 20. This hollow structure can reduce the weight of the electrode post 20 to some extent, thereby increasing the gravimetric energy density of the battery cell 100 and the battery 1000 to a certain extent.

[0126] At least a portion of the conductive part 32 is disposed within the through hole 211. That is, the conductive part 32 can be partially or completely disposed within the through hole 211. By partially or completely accommodating the conductive part 32 within the through hole 211, the portion of the conductive part 32 within the accommodating portion can occupy space within the electrode post 20. This reduces the space occupied by the conductive part 32 within the housing 10. When the size of the housing 10 is fixed, some space can be saved within the housing 10 to accommodate a larger active material coating portion 31, thereby increasing the volumetric energy density of the battery cell 100. Simultaneously, it can at least to some extent reduce the redundancy of the conductive part 32 within the housing 10, reducing the probability of short circuits between the conductive part 32 and the active material coating portion 31, lowering the probability of short circuits in the battery cell 100, and improving the operational reliability and stability of the battery cell 100 and the battery 1000.

[0127] According to an embodiment of the present invention, the battery cell 100, by providing a through hole 211 in the terminal post 20 and having at least a portion of the conductive part 32 disposed within the through hole 211, can reduce the space occupied by the conductive part 32 inside the housing 10, allowing the housing 10 to accommodate a larger active material coating part 31, thereby increasing the volumetric energy density of the battery cell 100. Simultaneously, it can reduce the redundancy of the conductive part 32 within the housing 10, lowering the probability of short circuits between the conductive part 32 and the active material coating part 31, reducing the probability of short circuits in the battery cell 100, and improving the operational reliability and stability of the battery cell 100 and the battery 1000. Furthermore, by providing the through hole 211 inside the terminal post 20, the weight of the terminal post 20 can be reduced, thereby increasing the gravimetric energy density of the battery cell 100 and the battery 1000.

[0128] According to some embodiments of the present invention, the cover plate 40 is welded to the conductive part 32.

[0129] Among them, welding can connect two items of different sizes and materials. It is simple to operate and does not require additional external materials. This simplifies the connection process between the cover plate 40 and the conductive part 32, reducing the production cost and overall weight of the battery cell 100. At the same time, the welding connection has high strength and good airtightness, which can increase the connection strength and stability between the cover plate 40 and the conductive part 32, thereby improving the stability of the electrical connection between the conductive part 32 and the terminal post 20.

[0130] In this embodiment, by welding the cover plate 40 to the conductive part 32, the connection strength and stability between the cover plate 40 and the conductive part 32 can be increased, thereby improving the stability of the electrical connection between the conductive part 32 and the terminal post 20. At the same time, the connection complexity between the cover plate 40 and the conductive part 32 can be reduced, thereby reducing the production cost and overall weight of the battery cell 100.

[0131] According to some embodiments of the present invention, such as Figure 4 As shown, the cover plate 40 has a first welding area 43 and a second welding area 44. The first welding area 43 is welded to the conductive part 32, and the second welding area 44 is used to weld the electrical connecting piece 50. The first welding area 43 and the second welding area 44 are different areas of the cover plate 40.

[0132] Specifically, the electrical connecting piece 50 is welded to the surface of the cover plate 40 facing away from the electrode assembly 30, which can be used to connect two adjacent battery cells 100 to realize the series connection of the battery cells 100; one end of the conductive part 32 is connected to the electrode assembly 30, and the other end is welded to the surface of the cover plate 40 facing the electrode assembly 30, which is used to connect the internal and external connections of the electrode assembly 30 to realize the electrical connection of the battery cells 100.

[0133] Understandably, during welding, under the action of the welding heat source, the base material on the workpiece melts locally, forming a liquid metal with a certain geometric shape. This part is called the molten pool, which forms the weld after cooling. The thickness at the weld location is slightly reduced relative to the cover plate body 41. Therefore, setting the first welding area 43 and the second welding area 44 as different regions of the cover plate 40 effectively prevents the welding quality degradation caused by the connection of the two weld pools. This improves the welding quality between the conductive part 32 and the electrical connecting piece 50 and the cover plate 40, thereby enhancing the electrical connection stability of the battery cell 100.

[0134] In this embodiment, by setting a first welding area 43 and a second welding area 44, the welding positions of the conductive part 32 and the electrical connecting piece 50 can be defined respectively, thereby increasing the convenience and reliability of assembling the battery cell 100. At the same time, by setting the first welding area 43 and the second welding area 44 as different areas of the cover plate 40, the problem of welding quality degradation caused by the connection of the two welding pools can be effectively prevented, thereby improving the welding quality of the conductive part 32 and the electrical connecting piece 50 to the cover plate 40, and thus improving the electrical connection stability of the battery cell 100.

[0135] According to some embodiments of the present invention, such as Figure 4 As shown, the first welding area 43 and the second welding area 44 are respectively formed on both sides of the center line of the cover plate 40 perpendicular to the length direction or the width direction.

[0136] That is, in some embodiments, the first welding area 43 and the second welding area 44 are respectively formed on both sides of the center line of the cover plate 40 perpendicular to the length direction; in other embodiments, the first welding area 43 and the second welding area 44 are respectively formed on both sides of the center line of the cover plate 40 perpendicular to the width direction.

[0137] In this embodiment, by setting the first welding area 43 and the second welding area 44 to be formed on both sides of the center line perpendicular to the length or width direction of the cover plate 40, the positions of the first welding area 43 and the second welding area 44 can be further defined, thereby increasing the convenience and reliability of assembling the battery cell 100.

[0138] According to some embodiments of the present invention, the distance between the first welding area 43 and the second welding area 44 is less than or equal to two-thirds of the width of the cover plate 40.

[0139] For example, the distance between the first welding area 43 and the second welding area 44 can be one-third or two-thirds of the width of the cover plate 40.

[0140] In this embodiment, by setting the distance between the first welding area 43 and the second welding area 44 to be less than or equal to two-thirds of the width of the cover plate 40, the distance between the first welding area 43 and the second welding area 44 is not too large. This helps to ensure the welding area of ​​the first welding area 43 and the second welding area 44 on the cover plate 40, so as to facilitate the connection between the conductive part 32 and the electrical connecting piece 50 and the cover plate 40, and ensure the welding quality between the conductive part 32 and the electrical connecting piece 50 and the cover plate 40, thereby improving the electrical connection stability of the battery cell 100.

[0141] According to some embodiments of the present invention, the distance between the first welding area 43 and the second welding area 44 is greater than or equal to one-third of the width of the cover plate 40.

[0142] In other words, the distance between the first welding area 43 and the second welding area 44 is greater than or equal to one-third of the width of the cover plate 40 and less than or equal to two-thirds of the width of the cover plate 40.

[0143] For example, if the distance between the first welding area 43 and the second welding area 44 is d, and the width of the cover plate 40 is w, then the range of d is [w / 3, 2w / 3].

[0144] In this embodiment, by setting the distance between the first welding area 43 and the second welding area 44 to be greater than or equal to one-third of the width of the cover plate 40, the distance between the first welding area 43 and the second welding area 44 is not too small. This can effectively prevent the problem of reduced welding quality caused by the connection of the two welding pools, thereby improving the welding quality of the conductive part 32 and the electrical connecting piece 50 with the cover plate 40, and thus improving the electrical connection stability of the battery cell 100.

[0145] According to some embodiments of the present invention, the distance between the first welding area 43 and the second welding area 44 is greater than or equal to 2 mm.

[0146] For example, the distance between the first welding area 43 and the second welding area 44 can be 2mm, 2.5mm, 3mm or more, and the distance can be designed according to the actual situation.

[0147] In this embodiment, by setting the distance between the first welding area 43 and the second welding area 44 to be greater than or equal to 2mm, the problem of reduced welding quality caused by the connection of the two welding pools can be effectively prevented. This can improve the welding quality of the conductive part 32 and the electrical connecting piece 50 to the cover plate 40, thereby improving the electrical connection stability of the battery cell 100.

[0148] According to some embodiments of the present invention, the first welding area 43 is welded to the conductive part 32 to form a first welding pool 431, and the second welding area 44 is welded to the electrical connecting piece 50 to form a second welding pool 441. The first welding pool 431 and the second welding pool 441 are arranged at intervals.

[0149] The molten pool refers to the portion of the base material that melts into a pool shape due to the heat of the welding arc. The liquid metal portion with a certain geometric shape formed on the workpiece during fusion welding is called the molten pool, and the molten pool forms a weld after cooling.

[0150] This embodiment effectively solves the problem of the first welding pool 431 and the second welding pool 432 being connected by setting the first welding pool 431 and the second welding pool 432 separately, thereby improving the welding quality of the conductive part 32 and the electrical connecting piece 50 to the cover plate 40, and thus improving the electrical connection stability of the battery cell 100.

[0151] According to some embodiments of the present invention, the ratio of the thickness of the cover plate 40 to the thickness of the first wall 11 is 1-4.

[0152] The housing 10 is mainly used to isolate the inside of the battery cell 100 from the outside, protect the battery cell 100, and ensure the safety of the battery cell 100. Therefore, the structural strength of the housing 10 must be sufficient to resist the expansion force of the battery cell and prevent it from breaking. The reaction force is also applied to the electrode assembly 30 to fix the electrode assembly 30. Therefore, the thickness of the first wall 11 must meet the strength requirements of the housing 10 and the lightweight requirements of the battery cell 100.

[0153] For example, the ratio of the thickness of the cover plate 40 to the thickness of the first wall 11 can be 1, 2, 3 or 4.

[0154] In this embodiment, by setting the ratio of the thickness of the cover plate 40 to the thickness of the first wall 11 to be 1-4, the thickness of the cover plate 40 can meet the welding requirements of the conductive part 32 and the electrical connecting piece 50, while also ensuring that the thickness of the cover plate 40 is not too thick, which is beneficial to the weight reduction of the battery cell 100.

[0155] According to some embodiments of the present invention, the ratio of the thickness of the cover plate 40 to the thickness of the first wall 11 is 2-3.

[0156] For example, the ratio of the thickness of the cover plate 40 to the thickness of the first wall 11 can be 2, 2.5 or 3.

[0157] In this embodiment, by setting the ratio of the thickness of the cover plate 40 to the thickness of the first wall 11 to 2-3, the thickness of the cover plate 40 can be further limited, so that the thickness of the cover plate 40 is not too large, which is beneficial to the weight reduction of the battery cell 100. At the same time, it also ensures that the thickness of the cover plate 40 is not too small, so that it can meet the welding requirements of the conductive part 32 and the electrical connecting piece 50 and the structural strength requirements of the battery cell 100.

[0158] According to some embodiments of the present invention, the thickness of the cover plate 40 is greater than or equal to 1.5 mm and less than or equal to 5 mm.

[0159] The thickness of the cover plate 40 is related to the welding requirements of the conductive part 32 and the electrical connecting piece 50.

[0160] For example, the thickness 'a' of the cover plate 40 can be 1.5mm, 2mm, 3mm, 4mm, or 5mm.

[0161] In this embodiment, by setting the thickness of the cover plate 40 to be greater than or equal to 1.5 mm and less than or equal to 5 mm, the thickness of the cover plate 40 can meet the welding requirements of the conductive part 32 and the electrical connecting piece 50, while also controlling the thickness of the cover plate 40 to avoid being too large. This reduces the space occupied by the cover plate 40 in the through hole 211, thereby improving the space utilization rate of the battery cell 100.

[0162] According to some embodiments of the present invention, such as Figure 5 As shown, the cover plate 40 includes a cover plate body 41 and a boss 42. The cover plate body 41 covers one end of the through hole 211. The boss 42 is provided on the side surface of the cover plate body 41 facing the electrode assembly 30 and extends into the through hole 211. The conductive part 32 is connected to the boss 42.

[0163] Specifically, the cover plate body 41 is mainly used to seal the end of the through hole 211 away from the electrode assembly 30, thereby sealing the battery cell 100; the boss 42 extends into the through hole 211, and the size of the boss 42 can be adapted to the through hole 211. The boss 42 can be used to further block the side of the through hole 211 away from the electrode assembly 30, thereby further sealing the through hole 211, further reducing the risk of electrolyte leakage from the through hole 211, and improving the reliability of the battery cell 100.

[0164] The electrical connecting piece 50 is welded to the side of the cover plate body 41 away from the boss 42, and the conductive part 32 is welded to the side of the boss 42 away from the cover plate body 41. This can further reduce the occurrence of weld pool connection during the welding process, thereby further improving the welding quality of the conductive part 32 and the electrical connecting piece 50 to the cover plate 40, and thus improving the electrical connection stability of the battery cell 100.

[0165] Furthermore, the cover plate body 41 and the boss 42 can be an integral part or separate parts. An integral part can reduce the production process of the cover plate 40, reduce the production steps of the cover plate 40, thereby increasing the production rate of the cover plate 40 and reducing the production cost of the cover plate 40. A separate part can reduce the production difficulty of the cover plate 40 and reduce the mold opening cost of the cover plate 40, thereby reducing the production cost of the cover plate 40.

[0166] This embodiment, by setting the cover plate body 41 and the boss 42, can increase the sealing effect between the cover plate 40 and the electrode post 20, further reduce the risk of electrolyte leakage from the through hole 211, and improve the reliability of the battery cell 100; at the same time, it can further reduce the occurrence of weld pool connection during the welding process, thereby further improving the welding quality of the conductive part 32 and the electrical connecting piece 50 to the cover plate 40, and thus improving the electrical connection stability of the battery cell 100.

[0167] According to some embodiments of the present invention, such as Figure 6 As shown, the boss 42 protrudes from one side surface of the cover plate body 41 by a height of 1mm-5mm.

[0168] For example, the height c of the boss 42 protruding from one side surface of the cover plate body 41 can be 1mm, 2mm, 3mm, 4mm or 5mm.

[0169] In this embodiment, by setting the height of the boss 42 protruding from one side surface of the cover plate body 41 to 1mm-5mm, the thickness of the boss 42 is not too large, which helps to reduce the space occupied by the cover plate 40 in the through hole 211, thereby improving the space utilization of the battery cell 100; it also ensures that the thickness of the boss 42 is not too small, so that the thickness of the boss 42 meets the welding requirements of the conductive part 32, thereby increasing the connection stability between the conductive part 32 and the boss 42.

[0170] According to some embodiments of the present invention, the boss 42 protrudes from one side surface of the cover plate body 41 by a height of 1.5mm-3mm.

[0171] For example, the height of the boss 42 protruding from one side surface of the cover plate body 41 can be 1.5mm, 2mm, 2.5mm or 3mm.

[0172] In this embodiment, by setting the height of the boss 42 protruding from one side surface of the cover plate body 41 to be 1.5mm-3mm, the thickness of the boss 42 can meet the welding requirements of the conductive part 32, while further reducing the space occupied by the cover plate 40 in the through hole 211, thereby further improving the space utilization rate of the battery cell 100.

[0173] According to some embodiments of the present invention, the boss 42 is clearance-fitted with one end of the through hole 211, and the clearance between the boss 42 and the through hole 211 is 0-0.1 mm.

[0174] Specifically, clearance fit refers to a fit with a gap, that is, when the boss 42 mates with the through hole 211, a gap is formed between the outer wall of the boss 42 and the inner wall of the through hole 211. The minimum gap can be zero.

[0175] For example, the clearance between the boss 42 and the through hole 211 can be 0mm, 0.01mm, 0.02mm, 0.04mm, 0.06mm, 0.08mm or 0.1mm.

[0176] In this embodiment, by setting a clearance fit between the boss 42 and one end of the through hole 211, and the clearance between the boss 42 and the through hole 211 is 0-0.1mm, it is beneficial for the boss 42 to enter and exit the through hole 211, thereby reducing the assembly difficulty of the cover plate 40 and the pole post 20.

[0177] According to some embodiments of the present invention, the fitting clearance between the boss 42 and the through hole 211 is less than or equal to 0.05 mm.

[0178] For example, the clearance between the boss 42 and the through hole 211 can be 0mm, 0.01mm, 0.02mm, 0.03mm, 0.04mm or 0.05mm.

[0179] In this embodiment, by setting the fitting gap between the boss 42 and the through hole 211 to be less than or equal to 0.05 mm, the gap between the boss 42 and the inner wall of the through hole 211 can be further reduced, thereby further improving the blocking effect of the boss 42 on the through hole 211, reducing the risk of electrolyte leakage from the cover plate 40, and thus improving the reliability of the battery cell 100.

[0180] According to some embodiments of the present invention, the electrode post 20 is a negative electrode post, the cover plate body 41 and the boss 42 are separate parts, the cover plate body 41 and the boss 42 are made of different materials, the material of the boss 42 is the same as the material of the conductive part 32, and when the boss 42 and the conductive part 32 are welded, the depth of the molten pool on the cover plate 40 is less than the thickness of the boss 42.

[0181] Specifically, the negative electrode post is connected to the negative electrode active material coating part through the negative electrode conductive part 32. The material of the conductive part 32 is the same as the material of the current collector of the active material coating part 31. The boss 42 is welded to the conductive part 32, and the material of the boss 42 is the same as the material of the negative electrode current collector. The cover plate body 41 is welded to the electrical connection piece 50, and the material of the cover plate body 41 can be the same as the material of the electrical connection piece 50.

[0182] For example, in some specific embodiments, the negative current collector is made of copper, meaning the conductive part 32 is made of copper, and the electrical connecting piece 50 is generally made of aluminum. Therefore, the boss 42 can be made of copper, and the cover plate body 41 can be made of aluminum. Welding the same materials together reduces welding difficulty and improves welding quality. Thus, having the conductive part 32, the negative current collector, and the boss 42 made of the same material reduces the welding difficulty between the conductive part 32 and the negative current collector, and between the conductive part 32 and the boss 42, improving the welding quality. Similarly, having the cover plate body 41 and the electrical connecting piece 50 made of the same material also reduces the welding difficulty between the electrical connecting piece 50 and the cover plate body 41, improving the welding quality.

[0183] In this embodiment, by using the electrode post 20 as the negative electrode post and setting the cover plate body 41 and the boss 42 as separate parts, and the material of the boss 42 is the same as the material of the conductive part 32, the material of the boss 42 and the conductive part 32 can be matched, thereby increasing the welding quality of the boss 42 and the conductive part 32 and increasing the connection stability of the boss 42 and the conductive part 32. In addition, when welding the boss 42 and the conductive part 32, the depth of the molten pool on the cover plate 40 is less than the thickness of the boss 42, and the welding position is controlled between the same materials, which can further increase the welding quality of the boss 42 and the conductive part 32 and reduce the welding difficulty of the boss 42 and the conductive part 32.

[0184] According to some embodiments of the present invention, the electrode post 20 is a positive electrode post, the boss 42 and the cover plate body 41 are integrally formed, and when the cover plate 40 is welded to the conductive part 32, the depth of the molten pool on the boss 42 is greater than the thickness of the boss 42.

[0185] Specifically, the positive electrode post is connected to the positive electrode active material coating part through the positive electrode conductive part. The material of the conductive part 32 is the same as the material of the current collector of the active material coating part 31, and thus the material of the boss 42 can be the same as the material of the positive electrode current collector.

[0186] For example, in some specific embodiments, the positive current collector is made of aluminum. That is, the conductive part 32 and the boss 42 can both be made of aluminum, and the electrical connection piece 50 is generally also made of aluminum. Therefore, the cover body 41 can be made of aluminum, so the cover body 41 and the boss 42 are made of the same material.

[0187] In this embodiment, when the electrode post 20 is a positive electrode post, the boss 42 is integrally formed with the cover plate body 41. This allows the cover plate 40 to meet the welding requirements with the electrical connection piece 50 and the conductive part 32, while also reducing the production process and steps of the cover plate 40. This can improve the production rate of the cover plate 40 and reduce its production cost.

[0188] According to some embodiments of the present invention, the pole post 20 is welded to the cover plate 40.

[0189] Among them, welding can connect two items of different sizes and materials. It is simple to operate and does not require additional external materials. This simplifies the connection process between the cover plate 40 and the terminal post 20, reducing the production cost and overall weight of the battery cell 100. At the same time, the welding connection has high strength and good airtightness, which can increase the connection stability and sealing of the cover plate 40 and the terminal post 20, thereby improving the sealing of the battery cell 100.

[0190] In this embodiment, by welding the terminal post 20 to the cover plate 40, the connection stability and sealing of the terminal post 20 and the cover plate 40 can be increased, thereby improving the gas seal of the battery cell 100 and thus improving the reliability of the battery cell 100.

[0191] According to some embodiments of the present invention, such as Figures 7-11 As shown, the pole post 20 is a hollow annular shape with a through hole 211 defined on its inner side.

[0192] Specifically, the pole post 20 is a hollow ring, that is, the inside of the pole post 20 forms a large hollow structure, and the transverse cross section of the pole post 20 forms a ring. The ring can be of various shapes, such as rectangle, circle, rhombus, etc.

[0193] In this embodiment, by setting the electrode post 20 as a hollow annulus and defining a through hole 211 on the inner side, the weight of the electrode post 20 can be reduced to a certain extent, thereby increasing the weight energy density of the battery cell 100 and the battery 1000. At the same time, the hollow annulus has a large internal cavity volume, which makes it easy for the conductive part 32 to extend out of the through hole 211, thereby reducing the welding difficulty of the conductive part 32 and the cover plate 40, reducing the assembly difficulty of the battery cell 100, and increasing the assembly rate of the battery cell 100.

[0194] According to some embodiments of the present invention, such as Figures 7-11 As shown, the electrode post 20 includes: an electrode post body 21, a first ring 22, and a second ring 23. The electrode post body 21 is annular and has a through hole 211 defined on its inner side. The first ring 22 is connected to one end of the electrode post body 21 facing the electrode assembly 30. The first ring 22 extends radially outward along the electrode post body 21 and extends circumferentially along the electrode post body 21 to form an annular shape. The second ring 23 is connected to the other end of the electrode post body 21 away from the electrode assembly 30. The second ring 23 extends radially outward along the electrode post body 21 and extends circumferentially along the electrode post body 21 to form an annular shape.

[0195] The pole body 21 is formed in a ring shape. For example, the cross-section of the pole body 21 can be formed into a circular ring, a rectangle, a rhombus, or other ring structure.

[0196] The surface of the first ring 22 facing the electrode assembly 30 can be flush with the surface of the electrode body 21 facing the electrode assembly 30. The shape of the first ring 22 can match the shape of the electrode body 21. The first ring 22 and the electrode body 21 can be separately set or integrally formed. The material of the first ring 22 can be the same as or different from the material of the electrode body 21. The thickness of the first ring 22 in the axial direction of the electrode body 21 can be reasonably set according to the installation and assembly requirements of the electrode 20. Optionally, the first ring 22 can be formed by flanges along the radial direction of the electrode body 21 from one end of the electrode body 21 facing the electrode assembly 30.

[0197] The surface of the second ring 23 facing the electrode assembly 30 can be flush with the surface of the electrode body 21 facing away from the electrode assembly 30. The shape of the second ring 23 can match the shape of the electrode body 21. The second ring 23 and the electrode body 21 can be separately set or integrally formed. The material of the second ring 23 can be the same as or different from the material of the electrode body 21. The thickness of the second ring 23 in the axial direction of the electrode body 21 can be reasonably set according to the installation and assembly requirements of the electrode 20. Optionally, the second ring 23 can be formed by flanges along the radial direction of the electrode body 21 from the end of the electrode body 21 facing away from the electrode assembly 30.

[0198] In this embodiment, a first ring 22 and a second ring 23 are respectively provided at both ends of the electrode post body 21. The first ring 22 and the second ring 23 can improve the structural strength of the electrode post body 21 to a certain extent, making the overall structural strength of the electrode post 20 better. This makes the connection and fixation of the electrode post 20 with the electrode tab more stable and reliable, and the electrode post 20 can better participate in the power transmission operation of the battery cell 100. The first ring 22 and the second ring 23 can cooperate with the electrode post body 21 to form a slot structure, thereby facilitating the installation and fixation of the electrode post 20 in the battery cell 100. The first ring 22 and the second ring 23 have a simple structure and are easy to use.

[0199] According to some embodiments of the present invention, such as Figure 11 As shown, a groove 212 is formed on the side surface of the electrode post 20 away from the electrode assembly 30, a through hole 211 is formed inside the groove 212 and penetrates the bottom wall of the groove 212, and a cover plate 40 is disposed in the groove 212.

[0200] Specifically, the shape of the groove 212 can be adapted to the shape and structure of the cover plate 40, and the depth of the groove 212 can be adapted to the thickness of the cover plate 40. The axis of the groove 212 can be collinear with the axis of the through hole 211. When the cover plate 40 is assembled with the electrode post 20, the surface of the cover plate 40 facing the electrode assembly 30 abuts against the bottom of the groove 212, and the periphery of the cover plate 40 abuts against the wall of the groove 212.

[0201] The groove 212 is connected to the through hole 211, which penetrates the bottom wall of the groove 212. The diameter of the through hole 211 is smaller than the diameter of the groove 212. The cover plate 40 faces the electrode assembly 30 and abuts against the bottom wall of the groove 212. It can be used to cover the through hole 211 to seal the battery cell 100, thereby effectively preventing electrolyte leakage from the through hole 211 and improving the reliability of the battery cell 100.

[0202] In this embodiment, by forming a groove 212 on the side surface of the pole post 20 away from the electrode assembly 30, the positioning of the cover plate 40 and the pole post 20 can be more convenient and the connection and fixation can be more stable and reliable.

[0203] According to some embodiments of the present invention, such as Figure 11 As shown, in the direction from the electrode assembly 30 toward the cover plate 40, the sidewall of the groove 212 extends radially outward along the through hole 211.

[0204] Specifically, the sidewall of the groove 212 extends outward along the radial direction of the connecting hole. The inclination angle of the sidewall can be reasonably set according to the installation and fixing requirements of the cover plate 40. The extension direction of the sidewall of the groove 212 can be matched with the extension direction of the periphery of the cover plate 40. The sidewall of the groove 212 can abut against the periphery of the cover plate 40.

[0205] For example Figure 11 As shown, the longitudinal section of the groove 212 can be formed into a trapezoid that is wider at the top and narrower at the bottom. The sidewall of the groove 212 is formed into an outwardly inclined slope. In this way, when the cover plate 40 and the pole post 20 are assembled, it can guide the assembly of the cover plate 40, so that the cover plate 40 can smoothly enter the groove 212. At the same time, the inclined slope has a relatively larger area than the vertical plane, which can increase the contact area between the cover plate 40 and the pole post 20, increase the welding width during welding, and thus improve the sealing effect between the cover plate 40 and the pole post 20.

[0206] In this embodiment, by setting the sidewall of the groove 212 to extend radially outward along the through hole 211, it can play a certain guiding role during the assembly of the cover plate 40 and the terminal post 20, making it easier to fix the cover plate 40 in the groove 212. The structure is simple and easy to assemble. At the same time, when the cover plate 40 and the terminal post 20 are welded together, the periphery of the cover plate 40 and the inclined sidewall of the groove 212 can increase the welding width during welding, so that the cover plate 40 and the terminal post 20 have a higher welding quality, thereby increasing the welding sealing effect of the cover plate 40 and the terminal post 20 and improving the sealing performance of the battery cell 100.

[0207] According to some embodiments of the present invention, the side surface of the cover plate 40 facing away from the electrode assembly 30 is flush with the end face of the pole post 20 facing away from the electrode assembly 30.

[0208] It is understandable that after the cover plate 40 is assembled with the electrode post 20, the cover plate 40 can cooperate with the electrode post 20 to form a continuous plane on the side of the electrode post 20 away from the electrode assembly 30. Specifically, the surface of the second ring 23 away from the electrode assembly 30 can be flush with the surface of the electrode post 20 away from the electrode assembly 30 and the surface of the cover plate 40 away from the electrode assembly 30.

[0209] For example Figures 4-5 As shown, the upper surface of the cover plate 40 is flush with the upper surface of the second ring 23 of the pole post 20.

[0210] In this embodiment, by setting one side surface of the cover plate 40 away from the electrode assembly 30 to be flush with one end face of the pole post 20 away from the electrode assembly 30, the cover plate 40 and the pole post 20 can be fitted together to form a continuous plane. This can reduce the space occupied by the cover plate 40 to a certain extent and increase the electrical connection surface of the pole post 20 of the battery cell 100, thereby improving the energy density of the battery cell 100. It also allows the battery cell 100 to be more easily electrically connected to the electrical connector through one end of the pole post 20 away from the electrode assembly 30. At the same time, it can also improve the appearance of the battery cell 100.

[0211] According to some embodiments of the present invention, the active material coating portion 31 includes a current collector and an active material layer disposed on the current collector, and the conductive portion 32 includes an electrode portion 321 electrically connected to the current collector. The electrode portion 321 includes a plurality of electrode tabs. The plurality of electrode tabs converge near the current collector to form a first gathering portion 3211, and the plurality of electrode tabs converge and connect away from the current collector to form a second gathering portion 3212. The first gathering portion 3211 connects the second gathering portion 3212 and the active material coating portion 31, and at least a portion of the second gathering portion 3212 is accommodated in the through hole 211.

[0212] Specifically, a current collector is a component used to carry active materials and collect and output the current generated by the battery's active materials. Current collectors include positive electrode current collectors and negative electrode current collectors, which are made of different materials. For example, in a lithium-ion battery, the positive electrode current collector can be made of aluminum, while the negative electrode current collector can be made of copper.

[0213] The active material layer is mainly coated on the current collector. The active material layer includes a positive active material layer and a negative active material layer. The positive and negative active materials have different functions, and therefore the materials of the positive and negative active materials are also different. For example, taking lithium-ion batteries as an example, the positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc., and the negative active material can be carbon or silicon, etc.

[0214] The tab portion 321 is the contact point of the battery cell 100 during charging and discharging. The tab portion 321 includes multiple tabs, for example, the number of tabs can be two, three, four or more. The tabs are electrically connected to the current collector but are not coated with active material, and can be formed by direct die-cutting of the current collector.

[0215] In the above technical solution, when multiple tabs form the first convergence portion 3211, they only converge (i.e., move closer together) but are not connected. However, when multiple tabs form the second convergence portion 3212, they not only converge but also connect into a single structure. For example, multiple tabs can be connected into a single plate structure by welding (e.g., ultrasonic welding) to form the second convergence portion 3212. Alternatively, multiple tabs can be converged and connected to form the second convergence portion 3212 by means of conductive adhesive bonding, etc., which will not be elaborated here.

[0216] It should be noted that, in the embodiments of this application, the electrode tabs are divided into positive electrode tabs and negative electrode tabs. The positive electrode tabs that need to be gathered together are stacked together and ultrasonically pre-welded to form the second gathering portion 3212 of the positive electrode. This reduces the interlayer gaps, allowing the loosely packed multiple positive electrode tabs to form a plate structure with a certain rigidity. Similarly, the negative electrode tabs that need to be gathered together are stacked together and ultrasonically pre-welded to form the second gathering portion 3212 of the negative electrode. This also reduces the interlayer gaps, allowing the loosely packed multiple negative electrode tabs to form a plate structure with a certain rigidity.

[0217] In the above technical solution, the phrase "multiple tabs converge near the current collector to form a first gathering portion 3211, and multiple tabs converge and connect away from the current collector to form a second gathering portion 3212" aims to illustrate that: along the extension direction of the tabs, the first gathering portion 3211 and the second gathering portion 3212 are arranged sequentially in the direction away from the current collector, and the specific positions of the first gathering portion 3211 and the second gathering portion 3212 are not limited; that is, it is not required that the first gathering portion 3211 be very close to the current collector, nor is it required that the second gathering portion 3212 be very far from the current collector. In some optional examples, the current collector and the tabs can be a single piece; for example, for the positive electrode, it can be an integrally formed aluminum foil, and for the negative electrode, it can be an integrally formed copper foil, etc.

[0218] In this embodiment, multiple tabs converge and connect to form a second convergent portion 3212, allowing the second convergent portion 3212 to have a smaller size and thickness. This makes it easier for the tab portion 321 to extend into the through hole 211 and connect with the cover plate 40, thereby increasing the convenience of connecting the conductive part 32 to the cover plate 40. Simultaneously, it effectively reduces the risk of short circuits between the tabs and the active material coating part 31 below the tab portion 321 due to tabs branching and inverted insertion, thus improving the reliability of the battery cell 100. Furthermore, by accommodating at least a portion of the second convergent portion 3212 within the through hole 211, the space of the terminal post 20 can be fully utilized, increasing the volumetric energy density of the battery cell 100.

[0219] According to some embodiments of the present invention, such as Figure 14 As shown, the conductive part 32 is fixedly connected to the cover plate 40 through the second gathering part 3212.

[0220] In this embodiment, by setting the conductive part 32 to be fixedly connected to the cover plate 40 through the second gathering part 3212, the composition of the battery cell 100 can be simplified, the use of parts can be reduced, the assembly process can be simplified, and the assembly efficiency can be improved.

[0221] According to some embodiments of the present invention, at least a portion of the first gathering portion 3211 is accommodated within the through hole 211.

[0222] In other words, at least a portion of the first gathering portion 3211 and at least a portion of the second gathering portion 3212 are both accommodated within the through hole 211.

[0223] In this embodiment, by setting at least a portion of the first gathering portion 3211 to be accommodated within the through hole 211, the space within the electrode post 20 can be utilized more fully, further reducing the space occupied by the tab portion 321 within the housing 10, so as to accommodate a larger active material coating portion 31, thereby increasing the volumetric energy density of the battery cell 100. Moreover, it can better reduce the redundancy of the tab portion 321 within the housing 10, further reducing the probability of short circuit between the tab portion 321 and the active material coating portion 31.

[0224] According to some embodiments of the present invention, the active material coating part 31 includes a current collector and an active material layer disposed on the current collector, and the conductive part 32 includes an electrode part 321 electrically connected to the current collector. The electrode part 321 includes a plurality of electrode tabs. The plurality of electrode tabs converge near the current collector to form a first gathering part 3211, and the plurality of electrode tabs converge and connect away from the current collector to form a second gathering part 3212. The first gathering part 3211 connects the second gathering part 3212 and the active material coating part 31. The conductive part 32 also includes an adapter piece. The adapter piece is connected to the second gathering part 3212. The conductive part 32 is electrically connected to the cover plate 40 through the adapter piece. At least a portion of the adapter piece is accommodated in the through hole 211.

[0225] Specifically, the active material coating part 31 can be electrically connected to the cover plate 40 through the first gathering part 3211, the second gathering part 3212, and the adapter piece in sequence. The conductive part 32 is electrically connected to the cover plate 40 at the location on the adapter piece, for example, by welding the adapter piece to the cover plate 40 (e.g., laser welding). In addition, the adapter piece and the tab are two separate components and are connected by welding (e.g., ultrasonic welding).

[0226] It is understood that, in this example, at least a portion of the second gathering portion 3212 is also accommodated within the through hole 211, and at least a portion of the first gathering portion 3211 may or may not be accommodated within the through hole 211.

[0227] In this embodiment, by providing an adapter plate, at least a portion of the second gathering portion 3212 and at least a portion of the adapter plate can be accommodated within the through hole 211. This allows for more efficient use of the space within the terminal post 20, further reducing the space occupied by the conductive portion 32 within the housing 10, thereby increasing the volumetric energy density of the battery cell 100. Simultaneously, the adapter plate can be used to avoid welding the portion of the second gathering portion 3212 to the terminal post 20, resulting in a more reliable weld between the adapter plate and the terminal post 20, reducing the risk of weld cracking, and further improving the reliability and stability of the battery cell 100. Furthermore, electrically connecting the terminal post 20 and the tab via the adapter plate simplifies the construction of the tab.

[0228] According to some embodiments of the present invention, at least a portion of the second gathering portion 3212 is located within the through hole 211; or, the entire second gathering portion 3212 is located within the through hole 211, and at least a portion of the first gathering portion 3211 is located within the through hole 211.

[0229] It is understood that in some specific embodiments of the present invention, the second gathering portion 3212 may be partially located within the through hole 211 or may be entirely located within the through hole 211, and the first gathering portion 3211 may be at least partially located within the through hole 211 or may not be located within the through hole 211.

[0230] In some other embodiments of the present invention, the second gathering portion 3212 is entirely located within the through hole 211, and at least a portion of the first gathering portion 3211 is located within the through hole 211. Specifically, the first gathering portion 3211 may be partially or entirely located within the through hole 211.

[0231] In this embodiment, by setting at least a portion of the second gathering portion 3212 within the through hole 211, the space within the terminal post 20 can be fully utilized, further reducing the space occupied by the tab portion 321 within the housing 10, thereby increasing the volumetric energy density of the battery cell 100. By setting the entire second gathering portion 3212 within the through hole 211, and at least a portion of the first gathering portion 3211 within the through hole 211, the space within the terminal post 20 can be utilized more fully, significantly reducing the space occupied by the tab portion 321 within the housing 10, thereby significantly increasing the volumetric energy density of the battery cell 100. At the same time, the redundancy of the tab portion 321 within the housing 10 can be further reduced, further reducing the probability of short circuit between the tab portion 321 and the active material coating portion 31.

[0232] According to some embodiments of the present invention, the second gathering portion 3212 extends along the surface of the cover plate 40. In the direction from the electrode assembly 30 toward the cover plate 40, one end of the first gathering portion 3211 is connected to the active material coating portion 31, and the other end of the first gathering portion 3211 extends obliquely toward the peripheral wall of the through hole 211 and extends to be connected to one end of the second gathering portion 3212.

[0233] Specifically, in the direction of the electrode assembly 30 toward the cover plate 40, the first gathering portion 3211 and the second gathering portion 3212 are arranged sequentially, and the active material coating portion, the first gathering portion 3211 and the second gathering portion 3212 are connected sequentially. When the cover plate 40 is fixedly connected to the electrode post 20, the second gathering portion 3212 extends along the surface of the cover plate 40, and the end of the first gathering portion 3211 away from the active material coating portion 31 extends obliquely toward the peripheral wall of the through hole 211. That is, the tab portion 321 is formed in a "Z" shape in the through hole 211, thereby reducing the space occupied by the tab portion 321.

[0234] In this embodiment, by setting a second gathering portion 3212 extending along the surface of the cover plate 40, and in the direction from the electrode assembly 30 toward the cover plate 40, one end of the first gathering portion 3211 is connected to the active material coating portion 31, and the other end of the first gathering portion 3211 extends obliquely toward the peripheral wall of the through hole 211 and extends to connect with one end of the second gathering portion 3212, the length of the first gathering portion 3211 accommodated inside the through hole 211 can be increased, thereby effectively reducing the space ratio of the tab inside the battery cell 100, so that a larger active material coating portion 31 can be accommodated, improving the volumetric energy density of the battery cell 100, and better reducing the redundancy of the tab portion 321 in the housing 10, further reducing the probability of short circuit between the tab portion 321 and the active material coating portion 31, and increasing the stability of the battery cell 100.

[0235] According to a method for preparing a battery cell 100 according to a second aspect of the present invention, the method includes: passing one end of a conductive portion 32 through a through hole 211 of a terminal post 20 and extending it from the other side of the terminal post 20; welding one end of the conductive portion 32 to a cover plate 40 on the other side of the terminal post 20; covering one end of the through hole 211 with the cover plate 40 and housing the conductive portion 32 within the through hole 211; and fixing the cover plate 40 to the terminal post 20.

[0236] Wherein, one end of the conductive part 32 refers to the end away from the active material coating part 31, which can also be understood as the second gathering part 3212 or the end of the adapter piece; the other side of the pole post 20 refers to the side of the second ring 23 of the pole post 20 away from the active material coating part 31; one end of the through hole 211 refers to the end of the through hole 211 away from the active material coating part 31.

[0237] In this embodiment, there are several ways to pass one end of the conductive part 32 through the through hole 211 of the electrode post 20. For example, the electrode assembly 30 can be laid flat, and then a cylinder can be used to push the electrode assembly 30 toward the electrode post 20, so that the conductive part 32 passes through the through hole 211 and extends out of the battery cell 100 from the side of the electrode post 20 away from the active material coating part 31. Alternatively, the housing 10 can be pushed toward the electrode assembly 30, so that the conductive part 32 passes through the through hole 211 and extends out of the battery cell 100 from the side of the electrode post 20 away from the active material coating part 31.

[0238] When the battery cell 100 is being manufactured, the end of the conductive part 32 facing away from the active material coating part 31 can be pushed toward the terminal post 20, thereby causing the end of the conductive part 32 facing away from the active material coating part 31 to extend out of the battery cell 100 from the side of the terminal post 20 facing away from the active material coating part 31. The extended portion of the conductive part 32 is welded to the cover plate 40 on the outside of the battery cell 100. This reduces the damage to the battery cell 100 caused by welding slag falling into the battery cell 100 during the welding process. Subsequently, the cover plate 40 is assembled with the terminal post 20, so that the cover plate 40 covers the end of the through hole 211 facing away from the active material coating part 31, and the electrode tab is bent and stored in the through hole 211. Then, the cover plate 40 is welded to the terminal post 20 to seal the battery cell 100.

[0239] According to the method for manufacturing the battery cell 100 of the present invention, the cover plate 40 and the conductive part 32 can be welded together on the outside of the battery cell 100. This reduces the damage to the battery cell 100 caused by welding slag falling into the battery cell 100 during the welding process, thereby improving the reliability of the battery cell 100. At the same time, the conductive part 32 can be housed in the through hole 211, which reduces the space occupied by the conductive part 32 inside the housing 10, allowing the housing 10 to accommodate a larger volume of the active material coating part 31, thereby increasing the energy density of the battery cell 100. In addition, the redundancy of the conductive part 32 can be reduced, further reducing the probability of short circuit between the conductive part 32 and the active material coating part 31, and increasing the stability of the battery cell 100.

[0240] In some specific embodiments of the present invention, before one end of the tab 321 passes through the through hole 211 of the pole post 20 and extends out from the other side of the pole post 20, the preparation method further includes: pre-welding multiple tab pieces of the tab 321 together.

[0241] Multiple tabs are stacked to form a tab, and these tabs can be connected together by ultrasonic pre-welding to form one end of the tab.

[0242] In this embodiment, multiple tabs of the tab portion 321 are connected into one piece by pre-welding, which can reduce the gap between the tabs and make one end of the tab portion 321 more compact, thereby facilitating the subsequent insertion of the tab portion 321 into the through hole 211 for operation.

[0243] According to some embodiments of the present invention, welding one end of the conductive part 32 to the cover plate 40 on the other side of the pole post 20 includes: pressing the other end of the conductive part 32 onto one side surface of the cover plate 40; and laser welding the other end of the conductive part 32 to the cover plate 40.

[0244] It is understandable that after the end of the conductive part 32 that is away from the active material coating part 31 extends out of the through hole 211, the end of the conductive part 32 that extends out is first pressed and fitted with the boss 42 of the cover plate 40 to ensure the welding gap, and then the conductive part 32 and the cover plate 40 are laser welded by laser.

[0245] Laser welding is a highly efficient and precise welding method that uses a high-energy-density laser beam as a heat source. It can achieve non-contact welding and has advantages such as high precision, high speed, and small deformation. Therefore, using laser welding to connect the conductive part 32 and the cover plate 40 can improve the connection speed between the conductive part 32 and the cover plate 40 and increase the welding quality between the conductive part 32 and the cover plate 40.

[0246] In this embodiment, by pressing the other end of the conductive part 32 onto one side surface of the cover plate 40, the welding gap can be ensured to achieve laser welding and improve the welding quality. By using laser welding to connect the conductive part 32 and the cover plate 40, the connection speed between the conductive part 32 and the cover plate 40 can be increased, and the welding quality between the conductive part 32 and the cover plate 40 can be improved.

[0247] In some specific embodiments of the present invention, fixing the cover plate 40 to the pole post 20 includes welding the cover plate 40 to the pole post 20.

[0248] Understandably, after the conductive part 32 is laser welded to the cover plate 40, the cover plate 40 is assembled to the electrode post 20. The cover plate 40 can be assembled into the groove 212 on the side of the electrode post 20 away from the electrode assembly 30. Then the cover plate 40 and the electrode post 20 are welded together to seal the end of the through hole 211 away from the active material coating part 31, and finally the assembly of the battery cell 100 is completed.

[0249] In this embodiment, by welding the cover plate 40 to the terminal post 20, the connection stability between the cover plate 40 and the terminal post 20 can be increased, thereby increasing the sealing performance of the battery cell 100 and improving the reliability of the battery cell 100.

[0250] The battery 1000 according to a third aspect embodiment of the present invention includes a battery cell 100 according to a first aspect embodiment of the present invention.

[0251] In some specific embodiments of the present invention, for example Figure 2 As shown, the battery 1000 may also include a main box 201 and an end cap 202. The main box 201 has a cavity with an open top, in which multiple battery cells 100 are disposed. The end cap 202 is sealed to the top of the main box 201 by fasteners.

[0252] Optionally, multiple battery cells 100 can be stacked and arranged in the cavity along the thickness direction of the battery cells 100.

[0253] Optionally, the main box 201 is formed into a rectangular box shape, with a cavity defined on the inner side of the main box 201 and an open top. The main box 201 is provided with a plurality of first fixing holes, and the end cover 202 is formed into a horizontally arranged flat plate shape. The end cover 202 is provided with a plurality of second fixing holes that penetrate the end cover 202 in the vertical direction. The plurality of first fixing holes and the plurality of second fixing holes correspond one-to-one and are vertically opposite each other. The battery 1000 also includes a plurality of fasteners, which pass through the first fixing holes and the second fixing holes to fasten the end cover 202 to the upper side of the main box 201.

[0254] Optionally, the end cap 202 can be made of carbon steel plate, aluminum plate or composite material plate.

[0255] In this embodiment, by setting the housing 200 as a separate main housing 201 and end cap 202, it is convenient to install the battery cell 100 into the housing 200. The main housing 201 and end cap 202 are connected by fasteners, which can realize a detachable connection, facilitate maintenance and replacement, and ensure the connection strength between the main housing 201 and end cap 202, thus ensuring the overall structural strength of the battery 1000.

[0256] In some specific embodiments of the present invention, a first adhesive layer is provided on the bottom wall of the cavity, and the bottom of the plurality of battery cells 100 is connected to the bottom wall of the main box 201 through the first adhesive layer; and / or, a second adhesive layer is provided on the end cap 202, and the top of the plurality of battery cells 100 is connected to the end cap 202 through the second adhesive layer.

[0257] The battery 1000 may include only the first adhesive layer, only the second adhesive layer, or both the first adhesive layer and the second adhesive layer. The first adhesive layer is used to bond the bottom wall of the main box 201 to the battery cell 100, and the second adhesive layer is used to bond the end cap 202 to the battery cell 100, so as to reliably fix the multiple battery cells 100 in the box 200, improve the reliability and stability of the connection between the battery cell 100 and the box 200, and effectively prevent the battery cell 100 from shaking in the box 200.

[0258] In this embodiment, by setting a first adhesive layer and a second adhesive layer, and by bonding and fixing the bottom of the battery cell 100 to the bottom wall of the main box 201 through the first adhesive layer, and bonding and fixing the top of the battery cell 100 to the end cap 202 through the second adhesive layer, the overall strength of the battery 1000 can be improved and the connection stability of the battery cell 100 can be guaranteed.

[0259] According to the battery 1000 of the present invention, by providing the battery cell 1000 of the first aspect embodiment described above, the overall performance of the battery 1000 is improved.

[0260] An electrical appliance according to a fourth aspect of the present invention includes a battery 1000 according to a third aspect of the present invention, the battery 1000 being used to provide electrical energy.

[0261] The electrical device can be any of the aforementioned devices or systems that use battery 1000.

[0262] According to embodiments of the present invention, by providing the battery 1000 of the third aspect embodiment described above, the overall performance of the electrical equipment is improved.

[0263] The following will refer to Figures 3-14 A battery cell 100 according to a specific embodiment of the present invention is described.

[0264] Reference Figure 3 The battery cell 100 includes a housing 10, a terminal post 20, a cover plate 40, and an electrode assembly 30. The housing 10 includes a first wall 11 and a receiving cavity. The terminal post 20 is disposed on the first wall 11 and has a through hole 211. The cover plate 40 is disposed on the side of the terminal post 20 away from the electrode assembly 30 and welded to the terminal post 20 to cover the end of the through hole 211 away from the electrode assembly 30. The electrode assembly 30 is disposed within the receiving cavity and includes an active material coating portion 31 and a conductive portion 32, and is the core component of the battery cell 100.

[0265] Specifically, the active material coating part 31 is the electrode sheet of the electrode assembly 30, and the conductive part 32 is the electrode tab of the electrode assembly 30. The electrode sheet has a positive electrode sheet and a negative electrode sheet, and includes a current collector and an active material layer disposed on the current collector. The electrode tab includes multiple tab pieces, which converge near the current collector to form a first gathering part 3211, and converge away from the current collector and connect to form a second gathering part 3212. The first gathering part 3211 connects the second gathering part 3212 and the active material coating part 31. At least a portion of the second gathering part 3212 is accommodated within the through hole 211 and welded to the cover plate 40.

[0266] The second gathering portion 3212 extends along the surface of the cover plate 40. In the direction from the electrode assembly 30 toward the cover plate 40, one end of the first gathering portion 3211 is connected to the active material coating portion 31, and the other end of the first gathering portion 3211 extends obliquely toward the peripheral wall of the through hole 211 and extends to connect with one end of the second gathering portion 3212 to form a "Z" shape.

[0267] The cover plate 40 includes a cover plate body 41 and a boss 42. The cover plate body 41 is used to cover one end of the through hole 211. The boss 42 is provided on the side surface of the cover plate body 41 facing the electrode assembly 30 and extends into the through hole 211. The boss 42 and the through hole 211 are in clearance fit. The conductive part 32 is connected to the side surface of the boss 42 facing the electrode assembly 30. The electrical connecting piece 50 is connected to the side surface of the cover plate body 41 away from the electrode assembly 30.

[0268] The cover plate 40 also has a first welding area 43 and a second welding area 44. The first welding area 43 and the second welding area 44 are respectively formed on both sides of the center line perpendicular to the length direction of the cover plate 40. The first welding area 43 is connected to the conductive part 32, and the second welding area 44 is connected to the electrical connecting piece 50. The first welding area 43 and the second welding area 44 are arranged indirectly, and the distance between the first welding area 43 and the second welding area 44 is greater than or equal to 2mm.

[0269] In addition, the thickness of the cover plate 40 is greater than or equal to 1.5 mm and less than or equal to 5 mm, the height of the boss 42 protruding from one side surface of the cover plate body 41 is 1.5 mm to 3 mm, and the fitting clearance between the boss 42 and the through hole 211 is less than or equal to 0.05 mm.

[0270] The electrode post 20 includes an electrode post body 21, a first ring 22, and a second ring 23. The electrode post body 21 is annular and has a through hole 211 defined on its inner side. The first ring 22 is integrally formed with the electrode post body 21 and is located in the receiving cavity. The first ring 22 is arranged around the outer peripheral surface of the electrode post body 21. The side surface of the first ring 22 facing the electrode assembly 30 is flush with the side surface of the electrode post body 21 facing the electrode assembly 30, and the other side abuts against the inner wall of the housing 10. The second ring 23 is integrally formed with the electrode post body 21 and is located outside the housing 10. The second ring 23 is arranged around the outer peripheral surface of the electrode post body 21. The side surface of the second ring 23 away from the electrode assembly 30 is flush with the side surface of the electrode post body 21 away from the electrode assembly 30, and the other side abuts against the housing 10.

[0271] A groove 212 is formed on the side surface of the pole post 20 facing away from the electrode assembly 30. In the direction from the electrode assembly 30 toward the cover plate 40, the sidewall of the groove 212 extends radially outward along the through hole 211. The through hole 211 is formed inside the groove 212 and passes through the bottom wall of the groove 212. The cover plate 40 is placed inside the groove 212 to cover the through hole 211. The outer surface of the cover plate 40 is flush with the outer surface of the pole post 20.

[0272] According to an embodiment of the present invention, the battery cell 100, by providing a through hole 211 in the terminal post 20 and having at least a portion of the conductive part 32 disposed within the through hole 211, can reduce the space occupied by the conductive part 32 inside the housing 10, allowing the housing 10 to accommodate a larger active material coating part 31, thereby increasing the volumetric energy density of the battery cell 100. Simultaneously, it can reduce the redundancy of the conductive part 32 within the housing 10, lowering the probability of short circuits between the conductive part 32 and the active material coating part 31, reducing the probability of short circuits in the battery cell 100, and improving the operational reliability and stability of the battery cell 100 and the battery 1000. Furthermore, by providing the through hole 211 inside the terminal post 20, the weight of the terminal post 20 can be reduced, thereby increasing the gravimetric energy density of the battery cell 100 and the battery 1000.

[0273] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, include: The housing (10) includes a first wall (11); The pole post (20) is disposed on the first wall (11) and has a through hole (211); A cover plate (40) is disposed on one side of the pole post (20) and covers one end corresponding to the through hole (211); The electrode assembly (30) includes an active material coating part (31) and a conductive part (32) connected to the active material coating part (31). The active material coating part (31) is disposed in the housing (10), and at least a portion of the conductive part (32) is disposed in the through hole (211) and connected to the cover plate (40). The active material coating portion (31) includes a current collector and an active material layer disposed on the current collector. The conductive portion (32) includes an electrode portion (321) electrically connected to the current collector. The electrode portion (321) includes a plurality of electrode tabs. The plurality of electrode tabs converge near the current collector to form a first convergence portion (3211), and the plurality of electrode tabs converge and connect away from the current collector to form a second convergence portion (3212). The first convergence portion (3211) connects the second convergence portion (3212) and the active material coating portion (31). At least a portion of the second gathering portion (3212) is accommodated within the through hole (211), or, The conductive part (32) further includes an adapter piece, which is connected to the second gathering part (3212). The conductive part (32) is electrically connected to the cover plate (40) through the adapter piece, and at least a portion of the adapter piece is accommodated in the through hole (211).

2. The battery cell according to claim 1, characterized in that, The cover plate (40) is welded to the conductive part (32).

3. The battery cell according to claim 1, characterized in that, The cover plate (40) has a first welding area (43) and a second welding area (44). The first welding area (43) is welded to the conductive part (32), and the second welding area (44) is used to weld the electrical connecting piece (50). The first welding area (43) and the second welding area (44) are different areas of the cover plate (40).

4. The battery cell according to claim 3, characterized in that, The first welding area (43) and the second welding area (44) are respectively formed on both sides of the center line of the cover plate (40) perpendicular to the length or width direction.

5. The battery cell according to claim 4, characterized in that, The distance between the first welding area (43) and the second welding area (44) is less than or equal to two-thirds of the width of the cover plate (40), and / or the distance between the first welding area (43) and the second welding area (44) is greater than or equal to one-third of the width of the cover plate (40).

6. The battery cell according to claim 3, characterized in that, The distance between the first welding area (43) and the second welding area (44) is greater than or equal to 2 mm.

7. The battery cell according to claim 3, characterized in that, The first welding area (43) is welded to the conductive part (32) to form a first welding pool (431), and the second welding area (44) is welded to the electrical connecting piece (50) to form a second welding pool (441). The first welding pool (431) and the second welding pool (441) are spaced apart.

8. The battery cell according to claim 1, characterized in that, The thickness of the cover plate (40) is 1-4 times the thickness of the first wall (11).

9. The battery cell according to claim 8, characterized in that, The thickness of the cover plate (40) is 2-3 times the thickness of the first wall (11).

10. The battery cell according to claim 1, characterized in that, The thickness of the cover plate (40) is greater than or equal to 1.5 mm and less than or equal to 5 mm.

11. The battery cell according to any one of claims 1 to 10, characterized in that, The cover plate (40) includes a cover plate body (41) and a boss (42). The cover plate body (41) covers one end of the through hole (211). The boss (42) is provided on the side surface of the cover plate body (41) facing the electrode assembly (30) and extends into the through hole (211). The conductive part (32) is connected to the boss (42).

12. The battery cell according to claim 11, characterized in that, The height of the boss (42) protruding from the side surface of the cover plate body (41) is 1mm-5mm.

13. The battery cell according to claim 12, characterized in that, The height of the boss (42) protruding from the side surface of the cover plate body (41) is 1.5mm-3mm.

14. The battery cell according to claim 11, characterized in that, The boss (42) is clearance-fitted with one end of the through hole (211), and the clearance between the boss (42) and the through hole (211) is 0-0.1mm.

15. The battery cell according to claim 14, characterized in that, The clearance between the boss (42) and the through hole (211) is less than or equal to 0.05 mm.

16. The battery cell according to claim 11, characterized in that, The electrode post (20) is a negative electrode post. The cover plate body (41) and the boss (42) are separate parts. The cover plate body (41) and the boss (42) are made of different materials. The material of the boss (42) is the same as that of the conductive part (32). When the boss (42) and the conductive part (32) are welded, the depth of the molten pool on the cover plate (40) is less than the thickness of the boss (42).

17. The battery cell according to claim 11, characterized in that, The electrode post (20) is a positive electrode post. The boss (42) and the cover plate body (41) are integrally formed. When the cover plate (40) is welded to the conductive part (32), the depth of the molten pool on the boss (42) is greater than the thickness of the boss (42).

18. The battery cell according to any one of claims 1 to 10, characterized in that, The pole post (20) is welded to the cover plate (40).

19. The battery cell according to any one of claims 1 to 10, characterized in that, The pole post (20) is a hollow annular shape and the through hole (211) is defined on the inner side.

20. The battery cell according to any one of claims 1 to 10, characterized in that, The pole (20) includes: The pole body (21) is annular and the through hole (211) is defined on its inner side; A first ring (22) is connected to one end of the electrode body (21) facing the electrode assembly (30). The first ring (22) extends radially outward along the electrode body (21) and extends circumferentially along the electrode body (21) in a ring shape. The second ring (23) is connected to the other end of the electrode body (21) away from the electrode assembly (30). The second ring (23) extends radially outward along the electrode body (21) and extends circumferentially along the electrode body (21) to form a ring.

21. The battery cell according to any one of claims 1 to 10, characterized in that, A groove (212) is formed on the side of the pole post (20) facing away from the electrode assembly (30). A through hole (211) is formed inside the groove (212) and penetrates the bottom wall of the groove (212). The cover plate (40) is disposed in the groove (212).

22. The battery cell according to claim 21, characterized in that, In the direction from the electrode assembly (30) toward the cover plate (40), the sidewall of the groove (212) extends radially outward along the through hole (211).

23. The battery cell according to claim 21, characterized in that, The side surface of the cover plate (40) facing away from the electrode assembly (30) is flush with the end face of the pole post (20) facing away from the electrode assembly (30).

24. The battery cell according to claim 1, characterized in that, The conductive part (32) is fixedly connected to the cover plate (40) through the second gathering part (3212).

25. The battery cell according to claim 1, characterized in that, At least a portion of the first gathering portion (3211) is accommodated within the through hole (211).

26. The battery cell according to claim 1, characterized in that, At least a portion of the second gathering portion (3212) is located within the through hole (211); or, The second gathering portion (3212) is entirely located within the through hole (211), and at least a portion of the first gathering portion (3211) is located within the through hole (211).

27. The battery cell according to claim 1, characterized in that, The second gathering portion (3212) extends along the surface of the cover plate (40). In the direction from the electrode assembly (30) toward the cover plate (40), one end of the first gathering portion (3211) is connected to the active material coating portion (31), and the other end of the first gathering portion (3211) extends obliquely toward the peripheral wall of the through hole (211) and extends to be connected to one end of the second gathering portion (3212).

28. A method for preparing a single battery cell, characterized in that, The battery cell is the battery cell according to any one of claims 1-27, and the preparation method includes: One end of the conductive part (32) is passed through the through hole (211) of the pole post (20) and then extends out from the other side of the pole post (20); One end of the conductive part (32) is welded to the cover plate (40) on the other side of the pole post (20); The cover plate (40) is placed over one end of the through hole (211), and the conductive part (32) is housed inside the through hole (211); The cover plate (40) is fixedly connected to the pole post (20).

29. The method for preparing a battery cell according to claim 28, characterized in that, The step of welding one end of the conductive part (32) to the cover plate (40) on the other side of the pole post (20) includes: The other end of the conductive part (32) is pressed onto one side surface of the cover plate (40); The other end of the conductive part (32) is laser welded to the cover plate (40).

30. A battery, characterized in that, Includes the battery cell according to any one of claims 1-27; or includes the battery cell prepared by the method of preparing the battery cell according to claim 28 or 29.

31. An electrical device, characterized in that, Includes the battery according to claim 30, the battery being used to provide electrical energy.

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