Battery cell

Abstract

The application relates to the battery technical field and discloses a battery monomer, which comprises a shell, an electric core and a first cover plate, the electric core is located in the shell, the electric core body has a first end face facing a first opening, a first tab is arranged on the first end face, the first tab comprises a first section, a second section and a third section which are sequentially connected, the first section is electrically connected with the electric core body, along a first direction, the second section is located between the first section and the third section; an electrode terminal is arranged on the first cover plate, wherein the length of the first tab between a first bending point and a second bending point is L, along a second direction, the first cover plate has oppositely arranged first and second side faces, the second bending point is located between the first side face and the first bending point, the distance between the second bending point and the first side face is d, and the following conditions are met: 1.2 <= L / d <= 6, and the second direction is perpendicular to the first direction. The technical problem that the tab is easily overlapped with the shell and causes the battery short circuit is solved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more particularly to a battery cell. Background Technology

[0002] As batteries serve as the core energy supply system for modern electronic devices, their safety, energy storage efficiency, and mechanical strength directly affect the lifespan of these devices and the user experience. In recent years, with the widespread adoption of smart devices and the increasing demand for miniaturized, high-capacity batteries, battery design and optimization have become a research hotspot.

[0003] In related technologies, a battery comprises multiple individual cells. Each cell mainly consists of a casing, the cell body, and tabs. The tabs, as crucial components connecting the cell to external electrical devices, extend from the cell to the electrode terminals. After the tabs are welded to the electrode terminals, the cover plate needs to be assembled with the casing. However, it is easy for the tabs to overlap with the casing, causing a short circuit in the battery. Utility Model Content

[0004] This application provides a battery cell that solves the technical problem of the tabs easily overlapping with the casing, causing a short circuit in the battery.

[0005] To achieve the above objectives, the main technical solutions adopted in this application include:

[0006] This application provides a battery cell comprising a casing, a battery cell, and a first cover plate. Along a first direction, one end of the casing has a first opening. The battery cell is located inside the casing and includes a battery cell body and a first electrode tab. Along the first direction, the battery cell body has a first end face facing the first opening. The first electrode tab is disposed on the first end face and includes a first segment, a second segment, and a third segment connected sequentially. The first segment is electrically connected to the battery cell body, and along the first direction, the second segment is located between the first segment and the third segment. The first cover plate is disposed on the casing and blocks the first opening. Along the first direction, the first cover plate has a bottom surface facing the battery cell body, and the bottom... The first cover plate is spaced apart from the first end face; the electrode terminal is disposed on the first cover plate, and the electrode terminal is connected to the third segment to form a first electrical connection area; wherein, a first bending point is formed at the connection between the first segment and the second segment, a second bending point is formed at the connection between the second segment and the third segment, the length of the first electrode ear between the first bending point and the second bending point is L, along the second direction, the first cover plate has a first side surface and a second side surface disposed opposite to each other, and the second bending point is located between the first side surface and the first bending point, the distance between the second bending point and the first side surface is d, satisfying: 1.2≤L / d≤6, and the second direction is perpendicular to the first direction.

[0007] The battery cell proposed in this application has a length L between the first bending point and the second bending point, and a distance d between the second bending point and the first side surface, satisfying: 1.2≤L / d≤6. This reduces the probability of a short circuit when the first tab overlaps with the casing, improving the stability and reliability of the battery cell and reducing the redundant length of the first tab, thus improving the assembly efficiency of the battery cell. On the other hand, it reduces the probability of the first tab tearing, improves the overcurrent capacity of the first tab, and reduces the probability of the battery cell overheating during high-power charging and discharging. Attached Figure Description

[0008] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0009] Figure 1 This is a schematic diagram of the overall structure of a battery cell provided in an embodiment of this application;

[0010] Figure 2 A schematic diagram illustrating the assembly process of a single battery cell provided in an embodiment of this application;

[0011] Figure 3 This is a schematic diagram of the welding and installation of a battery cell according to an embodiment of this application.

[0012] [Explanation of Labels in the Attached Image]

[0013] 1000 cells per battery.

[0014] Casing 100;

[0015] First opening 110;

[0016] Cell body 130; First end face 131; First surface 132; Second surface 133;

[0017] First pole piece 140; First segment 141; Second segment 142; Third segment 143; Fourth segment 144;

[0018] First cover plate 150; First side 151; Second side 152; Electrode terminal 153;

[0019] The first bend point is 160 degrees.

[0020] The second bend point is 170°.

[0021] Resistance welding fixture pressure plate 180;

[0022] First welding area 190;

[0023] First direction X; second direction Y. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0025] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0026] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0027] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0028] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0029] In this application, "multiple" refers to two or more (including two), and similarly, "multiple groups" refers to two or more (including two), and "multiple pieces" refers to two or more (including two).

[0030] As batteries serve as the core energy supply system for modern electronic devices, their safety, energy storage efficiency, and mechanical strength directly affect the lifespan of these devices and the user experience. In recent years, with the widespread adoption of smart devices and the increasing demand for miniaturized, high-capacity batteries, battery design and optimization have become a research hotspot.

[0031] In related technologies, a battery comprises multiple battery cells, which are mainly composed of a casing, a cell body, and tabs. The tabs connect to the electrode terminals on the cell body and the cover plate. The tabs extend from the cell body, with one end welded to the electrode terminal and the other end connected to the cell body. Because battery cells need to meet the requirements of lightweighting and miniaturization, the tabs need to be bent to reduce their space occupation within the battery cell. However, even after bending, the tabs still have some length redundancy, occupying a significant amount of space inside the casing, leading to reduced assembly efficiency of the battery cell.

[0032] In view of this, this application proposes a battery cell, which includes a casing, a battery cell, and a first cover plate. Along a first direction, one end of the casing has a first opening. The battery cell is located inside the casing and includes a battery cell body and a first electrode tab. Along the first direction, the battery cell body has a first end face facing the first opening. The first electrode tab is disposed on the first end face and includes a first segment, a second segment, and a third segment connected in sequence. The first segment is electrically connected to the battery cell body, and along the first direction, the second segment is located between the first segment and the third segment. The first cover plate is disposed on the casing and blocks the first opening. Along the first direction, the first cover plate has a bottom surface facing the battery cell body. Electrode terminals are disposed on the first cover plate, and the electrode terminals are connected to the third segment to form a first electrical connection area.

[0033] The first segment and the second segment form a first bending point, and the second segment and the third segment form a second bending point. The length of the first electrode ear between the first bending point and the second bending point is L. Along the second direction, the first cover plate has a first side and a second side that are arranged opposite to each other, and the second bending point is located between the first side and the first bending point. The distance between the second bending point and the first side is d, which satisfies: 1.2≤L / d≤6. The second direction is perpendicular to the first direction.

[0034] In the above scheme, the length between the first bending point and the second bending point is L, and the distance between the second bending point and the first side is d, satisfying: 1.2≤L / d≤6. This can reduce the probability of short circuit when the first tab overlaps with the casing, improve the stability and reliability of the battery cell, and reduce the redundant length of the first tab, thereby improving the assembly efficiency of the battery cell. On the other hand, it can reduce the probability of the first tab tearing, improve the overcurrent capacity of the first tab, and reduce the probability of the battery cell overheating during high-power charging and discharging.

[0035] In some embodiments, the battery can be a battery module, and when there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0036] In some embodiments, the battery can be a battery pack, which includes a battery housing and individual battery cells, with the individual battery cells or battery modules housed within the battery housing.

[0037] In some embodiments, the battery cell can be a rechargeable battery, which refers to a battery cell that can be recharged after discharge to activate the active materials and continue to be used. The battery cell can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0038] In some embodiments, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0039] In some embodiments, the battery cell includes, but is not limited to, lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, etc.

[0040] The battery disclosed in this application can be used, but is not limited to, in vehicles, and can also be used in other electrical devices with structural beams, wherein the battery is able to avoid the structural beams of other electrical devices.

[0041] The battery disclosed in this application can be used, but is not limited to, in electrical devices such as vehicles, ships, or aircraft that have longitudinal beams and are designed to allow the battery to avoid obstructing these beams. A power system for such an electrical device can be constructed using the battery disclosed in this application.

[0042] This application provides an electrical device that uses a battery as a power source. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric bicycles, electric motorcycles, electric cars, ships, heavy trucks, buses, spacecraft, etc. Among them, electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0043] The convergence disclosed in this application refers to bending and stacking the first electrode tab to reduce the space occupied by the first electrode tab inside the housing.

[0044] It should be noted that the appendix Figure 2 and attached Figure 3 These are all for the purpose of better showing the structure and size of the battery cell, and are not schematic diagrams of the actual structure of the battery cell in use.

[0045] The length L between the first bending point and the second bending point, as well as the distance d between the second bending point and the first side surface disclosed in this application embodiment, are measured when the battery cell is actually assembled.

[0046] For ease of explanation, the following embodiments use a single battery cell from one embodiment of this application as an example.

[0047] The battery casing includes a housing and a cover. The housing encapsulates components such as the battery cell and electrolyte. The housing can come in various shapes and sizes, such as cuboid, cylindrical, and hexagonal prism. The shape of the housing can be determined based on the specific shape and size of the battery cell. The housing can be made of various materials, including but not limited to copper, iron, aluminum, stainless steel, and aluminum alloy.

[0048] A cover is a component that closes onto the opening of a housing to isolate the contained space from the external environment. The shape of the cover can be adapted to fit the shape of the housing. Covers can be made of materials with a certain degree of hardness and strength (such as aluminum alloy).

[0049] A battery cell is the smallest charging and discharging unit. A battery cell consists of a positive electrode, a negative electrode, and a separator between them, formed by winding or stacking. The positive electrode includes a positive current collector and a positive active material. The positive current collector can be made of metals such as aluminum foil, nickel foil, or stainless steel, or a composite foil formed by combining metals and insulating materials. The positive active material includes the main positive active material, a conductive agent, and a binder. The main positive active material includes one or more of lithium-containing positive active materials such as lithium iron phosphate, ternary materials containing nickel, cobalt, and manganese, and lithium manganese iron phosphate. Similarly, the negative electrode includes a negative current collector and a negative active material. The negative current collector can be made of metals such as copper foil, aluminum foil, or stainless steel, or a composite foil formed by combining metals and insulating materials. The negative active material includes the main negative active material, a conductive agent, and a binder. The main negative active material includes one or more of the main negative active materials such as artificial graphite, natural graphite, silicon carbide, silicon oxide, and lithium titanate. The tabs serve as the current output terminals of the battery cell, and are either integrally connected to the positive or negative electrode plate or connected separately. The separator, as an insulating layer, prevents short circuits within the battery cell caused by contact between the positive and negative electrodes. Furthermore, as a semi-permeable layer, the separator prevents larger molecules from passing through while allowing smaller charged ions to pass. The base of the tab is the edge of the active material coating area of ​​the electrode plate. The electrode terminals are the current output terminals of the battery.

[0050] Figure 1 This is a schematic diagram of the overall structure of a battery cell provided in an embodiment of this application; Figure 2 A schematic diagram illustrating the assembly process of a single battery cell provided in an embodiment of this application; Figure 3 This is a schematic diagram of the welding and installation of a battery cell according to an embodiment of this application.

[0051] Please refer to Figure 1 and Figure 2The battery cell 1000 includes a housing 100, a battery cell, and a first cover plate 150. Along the first direction X, one end of the housing 100 has a first opening 110. The battery cell is located inside the housing 100 and includes a battery cell body 130 and a first tab 140. Along the first direction X, the battery cell body 130 has a first end face 131 facing the first opening 110. The first tab 140 is disposed on the first end face 131 and includes a first segment 141, a second segment 142, and a third segment 143 connected sequentially. The first segment 141 is electrically connected to the battery cell body 130. Along the first direction X, the second segment 142 is located between the first segment 141 and the third segment 143. The first cover plate 150 is disposed on the housing 100 and blocks the first opening 110. Along the first direction X, the first cover plate 150 has a bottom surface facing the battery cell body 130. The bottom surface is spaced apart from the first end face 131; the electrode terminal 153 is disposed on the first cover plate 150, and the electrode terminal 153 is connected to the third segment 143 to form a first electrical connection area; wherein, a first bending point 160 is formed at the connection between the first segment 141 and the second segment 142, and a second bending point 170 is formed at the connection between the second segment 142 and the third segment 143, the length of the first electrode tab 140 between the first bending point 160 and the second bending point 170 is L, along the second direction Y, the first cover plate 150 has a first side surface 151 and a second side surface 152 disposed opposite to each other, and the second bending point 170 is located between the first side surface 151 and the first bending point 160, the distance between the second bending point and the first side surface 151 is d, satisfying: 1.2≤L / d≤6, the second direction Y is perpendicular to the first direction X.

[0052] Along the first direction X, the housing 100 has two ends, and one end of the housing 100 is provided with a first opening 110. For example, the battery cell can be placed into the housing 100 through the first opening 110. The battery cell includes a battery cell body 130 and a first electrode 140. The battery cell body 130 is used to store electrical energy. Along the first direction X, the battery cell body 130 has a first end face 131 facing the first opening 110. The first electrode 140 is disposed on the first end face 131 of the battery cell body 130 and leads out from the first end face 131 of the battery cell body 130. For example, the battery cell body 130 can be constructed as a laminated battery cell. The laminated battery cell includes multiple electrodes. The first electrode 140 includes multiple first sub-electrodes. Each first electrode 140 is led out from each electrode. The first electrode 140 can be a positive electrode or a negative electrode.

[0053] The first tab 140 includes a first segment 141, a second segment 142, and a third segment 143 connected in sequence. The two ends of the second segment 142 are connected to the first segment 141 and the third segment 143, respectively. The first segment 141 is connected to the cell body 130. That is to say, when the cell body 130 is charging and discharging, the current can flow out of the cell body 130 and first enter the first segment 141. The current can also flow into the cell body 130 from the first segment 141.

[0054] A first cover plate 150 is disposed on the housing 100. The first cover plate 150 can seal the first opening 110 of the housing 100, thereby reducing the probability of external impurities entering the interior of the housing 100. Along the first direction X, the first cover plate 150 has a bottom surface facing the cell body 130. That is, when the first cover plate 150 seals the housing 100, the bottom surface of the first cover plate 150 can be located inside the housing 100. Along the first direction X, the bottom surface is spaced apart from the first end face 131 of the cell body 130. The bottom surface and the third segment 143 are connected to form a first connection area. It can be understood that current can flow from the cell body 130 into the first segment 141, then from the first segment 141 into the second segment 142, and from the second segment 142 into the third segment 143. The third end is connected to the bottom surface of the first cover plate 150, thereby allowing current to flow into the first cover plate 150. For example, an electrical device can be connected to the first cover plate 150 to utilize the electrical energy stored in the battery cell 1000.

[0055] The third segment 143 of the first tab 140 is electrically connected to the electrode terminal 153 disposed on the first cover plate 150 to form a first electrical connection area. This connection method allows the current to be effectively transmitted from the cell body 130 to the electrode terminal 153 through the first tab 140. Moreover, due to the bending design of the first tab 140, the connection area between the first tab 140 and the electrode terminal 153 is increased to a certain extent, thereby improving the stability and conductivity of the connection, reducing the contact resistance, and helping to improve the charging and discharging performance and overall efficiency of the battery cell 1000.

[0056] A first bending point 160 is formed at the connection between the first segment 141 and the second segment 142. The second segment 142 bends toward the first opening 110 and is located between the first opening 110 and the first segment 141. The first segment 141 and the second segment 142 are set at an angle. Along the first direction X, at least part of the projections of the first segment 141 and the second segment 142 overlap. A second bending point 170 is formed between the second segment 142 and the third segment 143. The third segment 143 bends toward the first opening 110, that is, the third segment 143 is located between the second segment 142 and the first cover plate 150.

[0057] The first tab 140 is designed as a first segment 141, a second segment 142, and a third segment 143 connected in sequence, with bending points (first bending point 160 and second bending point 170) formed at the connections between the first segment 141 and the second segment 142, and between the second segment 142 and the third segment 143. This structural design allows for more flexible arrangement of the first tab 140 within the housing 100, better adapting to the internal space of the housing 100 and the relative positional relationship between the cell body 130 and the first cover plate 150. This is beneficial for improving the utilization rate of the internal space of the battery cell 1000, and also facilitates the connection of the first tab 140 with the cell body 130 and the first cover plate 150.

[0058] In some embodiments of this application, L / d can be 1.2, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, or 6.0, etc.

[0059] The length between the first bending point 160 and the second bending point 170 is L. Along the second direction Y, the first cover plate 150 has a first side surface 151 and a second side surface 152 that are disposed opposite to each other. The second bending point 170 is located between the first side surface 151 and the first bending point 160. The distance between the second bending point and the first side surface 151 is d. In order to ensure the performance of the first tab 140, L / d should not be too large or too small. For example, when L / d is too large, the first tab 140 is prone to overlap with the casing 100, which may lead to a short circuit in the battery. When L / d is too small, the first tab 140 is prone to being too tight, which increases the risk of tearing of the first tab 140 and reduces the current carrying capacity of the first tab 140. When the battery cell 1000 is fast charged at high power, the heat generated by the first tab 140 is too large, which may lead to safety risks such as thermal runaway of the battery. At the same time, it affects the overall charge and discharge rate of the battery and reduces the performance of the battery. When the overall length of the first tab 140 remains unchanged, and the length L between the first bending point 160 and the second bending point 170 is too small, the third segment 143 of the first tab 140 is too long, resulting in redundancy of the third segment 143. When assembling the battery cell 1000, the third segment 143 needs to be shortened, which leads to low assembly efficiency of the battery cell 1000.

[0060] Specifically, the length between the first bending point 160 and the second bending point 170 is L, and the distance between the second bending point and the first side 151 is d, satisfying: 1.2≤L / d≤6. By controlling L / d within a reasonable range, on the one hand, the probability of a short circuit occurring when the first tab 140 overlaps with the casing 100 can be reduced, improving the stability and reliability of the battery cell 1000. On the other hand, it can reduce the probability of the first tab 140 tearing, improve the overcurrent capacity of the first tab 140, reduce the probability of the battery cell 1000 overheating during high-power charging and discharging, reduce the redundant length of the first tab 140, and improve the assembly efficiency of the battery cell 1000.

[0061] In some embodiments, the convergence length of the first electrode 140 refers to the length of overlap of the first electrode 140 in the first direction X, such as the portion where the second segment 142 and the third segment 143 overlap, which can be the convergence length of the first electrode 140.

[0062] For example, before the first tab 140 bends or converges at the second bending point 170, the battery cell 1000 follows... Figure 3 When placed in the indicated orientation, the first electrode tab 140 is bent by the resistance welding fixture pressure plate 180 to form the first bending point 160. At this time, the electrode terminal 153 is welded to the first electrode tab 140, and the electrode terminal 153 is welded to the third segment 143 to form the first welding area 190. The welding fixing method includes, but is not limited to, laser welding, ultrasonic welding, etc.

[0063] Please refer to Figure 1 and Figure 2 In this embodiment, the length L of the first tab 140 between the first bending point 160 and the second bending point 170 satisfies: 4mm≤L≤28mm.

[0064] For example, L can be 4mm, 6mm, 8mm, 9mm, 12mm, 15mm, 20mm, 24mm, 25mm or 28mm, etc.

[0065] The length L of the first tab 140 between the first bending point 160 and the second bending point 170 satisfies: 4mm≤L≤28mm. This avoids the first tab 140 being too long, reducing the probability of short circuits between the first tab 140 and the housing 100 or the first cover plate 150. It also avoids the first tab 140 being too short, improving its current carrying capacity, reducing the probability of tearing, reducing the probability of overheating of the battery cell 1000, improving the stability and reliability of the battery cell 1000, reducing the probability of redundancy at the third end of the first tab 140, and improving the assembly efficiency of the battery cell 1000.

[0066] Please refer to Figure 1 and Figure 2 In this embodiment, along the second direction Y, the distance between the second bending point and the first side 151 is d, which satisfies 1.5mm≤d≤15mm.

[0067] For example, d can be 1.5mm, 1.8mm, 2.0mm, 2.5mm, 3.0mm, 5mm, 7mm, 9mm, 12mm, 14mm or 15mm, etc.

[0068] Along the second direction Y, the distance d between the second bending point and the first side 151 is too large, which means that the length of the first segment 141 of the first tab 140 is reduced. This will result in an excessively long redundant length of the third segment 143 of the first tab 140, resulting in a poor convergence effect of the first tab 140, which in turn reduces the assembly efficiency of the battery cell 1000. If the distance d between the second bending point and the first side 151 is too small, the first tab 140 is prone to overlap with the casing 100, which can easily cause a short circuit in the battery cell 1000.

[0069] Specifically, along the second direction Y, the distance between the second bending point and the first side 151 is d, which satisfies 1.5mm≤d≤15mm. This can improve the convergence effect of the first tab 140, reduce the probability of redundancy in the first tab 140, and thus improve the assembly efficiency of the battery cell 1000. On the other hand, it can reduce the probability of overlap between the first tab 140 and the casing 100, and improve the stability and reliability of the battery cell 1000.

[0070] Please refer to Figure 1 and Figure 2 In this embodiment, along the second direction Y, the battery cell body 130 has a first surface 132 and a second surface 133 arranged opposite to each other. The distance between the first surface 132 and the second surface 133 is t, and the distance between the first bending point 160 and the first surface 132 is a, satisfying: a≥t / 2.

[0071] For example, 'a' can be 1.6mm, 2.0mm, 3.0mm, 4.5mm, 8mm, 12mm, 15mm, 20mm, 25mm, 30mm, or 34mm, etc.

[0072] For example, t can be 3mm, 5mm, 10mm, 15mm, 20mm, 25mm, 30mm, 34mm or 35mm, etc.

[0073] The second surface 133 is closer to the first bending point 160 than the first surface 132. The first bending point 160 is located between the second bending point 170 and the second surface 133. The distance between the first surface 132 and the second surface 133 is t. The greater the distance a between the first bending point 160 and the first surface 132, the longer the first segment 141 of the first electrode 140 will be, which can reduce the probability of redundancy of the first electrode 140.

[0074] Specifically, the distance between the first surface 132 and the second surface 133 is t, and the distance between the first bending point 160 and the first surface 132 is a, satisfying: a≥t / 2. This allows the first segment 141 of the first tab 140 to have a longer convergence length, reducing the redundancy of the first tab 140, improving the assembly efficiency of the battery cell 1000, reducing the probability of the first tab 140 overlapping with the casing 100 or the first cover plate 150, reducing the probability of the battery cell 1000 short-circuiting and failing, and improving the stability and reliability of the battery cell 1000 in use.

[0075] Please refer to Figure 1 and Figure 2 In this embodiment, the length between the first bending point 160 and the second bending point 170 is L, and the distance between the second bending point and the first side 151 is d, satisfying: 1.2≤L / d≤5.8.

[0076] In some embodiments of this application, L / d can be 1.2, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0 or 5.8, etc.

[0077] This reduces the probability of the first tab 140 overlapping with the housing 100 or the first cover plate 150, while ensuring a good convergence effect of the first tab 140, thereby reducing the probability of short circuit in the battery cell 1000 and improving the stability and reliability of the battery cell 1000.

[0078] Please refer to Figure 1 and Figure 2 Along the second direction Y, the battery cell body 130 has a first surface 132 and a second surface 133 that are arranged opposite to each other. The distance between the first surface 132 and the second surface 133 is t, and the distance between the first bending point 160 and the first surface 132 is a, satisfying: a < t / 2.

[0079] For example, 'a' can be 0.2mm, 0.8mm, 1.8mm, 2.6mm, 4.0mm, 6.0mm, 10mm, 15mm, 16mm, or 17mm, etc.

[0080] For example, t can be 3mm, 5mm, 7mm, 9mm, 13mm, 20mm, 25mm, 27mm, 30mm, 33mm or 35mm, etc.

[0081] Under the condition that the length of the first electrode tab 140 bent and contracted within the housing 100 is within a reasonable range, the length of the first electrode tab 140 between the first bending point 160 and the second bending point 170 can be reduced, thereby reducing the connection length between the first electrode tab 140 and the first electrode terminal 153 on the first cover plate 150, reducing the risk of poor current carrying capacity due to excessive length of the first electrode tab 140 and the first electrode terminal 153 on the first cover plate 150, and improving the space utilization rate within the housing 100.

[0082] Please refer to Figure 1 and Figure 2 In this embodiment, the length between the first bending point 160 and the second bending point 170 is L, and the distance between the second bending point and the first side surface 151 is d, satisfying: 1.4≤L / d≤6.

[0083] For example, L / d can be 1.4, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.8 or 6.0, etc.

[0084] Since a < t / 2 and 1.4 ≤ L / d ≤ 6, the connection length between the first tab 140 and the first electrode terminal 153 is within a reasonable range. This can reduce the probability of short circuit between the first tab 140 and the first cover plate 150 or the housing 100 while ensuring that the overcurrent capacity of the first tab 140 is within a reasonable range, reduce the redundant length of the first tab 140, improve the convergence effect of the battery cell 1000, and improve the assembly efficiency of the battery cell 1000.

[0085] Please refer to Figure 1 and Figure 2 In this embodiment, the first tab 140 further includes a fourth segment 144. Along the length direction of the third segment 143, one end of the third segment 143 is connected to the second segment 142, and the other end of the third segment 143 is connected to the fourth segment 144. Along the first direction X, the fourth segment 144 is located on the side of the third segment 143 facing the cell body 130.

[0086] The first tab 140 also includes a fourth segment 144. The third segment 143 of the first tab 140 is connected to the bottom surface of the first cover plate 150 to form a first connection area. Along the length direction of the third segment 143, one end of the third segment 143 is connected to the second end, and the other end of the third segment 143 is connected to the fourth segment 144. The fourth segment 144 can be a redundant part of the first tab 140. That is to say, the battery cell 1000 needs to bundle and assemble the fourth segment 144. The longer the length of the fourth segment 144, the lower the assembly efficiency of the battery cell 1000.

[0087] Along the first direction X, the fourth segment 144 is located on the side of the third segment 143 facing the cell body 130. That is, along the first direction X, the fourth segment 144 is located between the third segment 143 and the second segment 142. Along the first direction X, at least part or all of the projection of the third segment 143 falls on the third segment 143 or the second segment 142. This can effectively utilize the space inside the housing 100 and improve the space utilization rate inside the battery cell 1000. The fourth segment 144 has a high space utilization rate inside the housing 1000, which improves the assembly efficiency of the battery cell 1000.

[0088] Please refer to Figure 1 and Figure 2 In this embodiment, the length between the first bending point 160 and the second bending point 170 is L, and the distance between the second bending point and the first side 151 is d, satisfying: 1.2≤L / d≤5.8.

[0089] For example, L / d can be 1.2, 1.4, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0 or 5.8, etc.

[0090] In this way, under the condition that the fourth segment 144 is converged, the convergence effect of the first tab 140 is guaranteed, the space occupied by the first tab 140 in the housing 100 is reduced, the connection length between the first tab 140 and the first electrode terminal 153 on the first cover plate 150 is shorter, the resistance of the first tab 140 is reduced, the overcurrent capacity of the first tab 140 is improved, the probability of the battery cell 1000 overheating is reduced, and the stability and reliability of the battery cell 1000 in use are improved.

[0091] Please refer to Figure 1 and Figure 2 In this embodiment, the first electrical connection area includes a first welding area 190 along the second direction Y. The size of the first welding area 190 is D1, and D1 satisfies: 1mm≤D1≤14mm.

[0092] For example, D1 can be 1mm, 2mm, 4mm, 5mm, 10mm, 12mm or 14mm, etc.

[0093] The first connection area includes a first welding area 190. For example, the first tab 140 can be welded to the first electrode terminal 153 of the first cover plate 150. Along the second direction Y, the larger the size D1 of the first welding area 190, the closer the second bending point 170 is to the first side 151, which increases the probability of the first tab 140 overlapping with the first cover plate 150 or the housing 100, causing a short circuit in the battery cell 1000. Conversely, the smaller the size D1 of the first welding area 190, the smaller the connection area between the first tab 140 and the first electrode terminal 153, and the reduced current carrying capacity of the first tab 140.

[0094] The first welding area 190 has a size of D1, which satisfies the condition: 1mm≤D1≤14mm. This ensures the current carrying capacity of the first tab 140 and reduces the probability of the first tab 140 overlapping with the housing 100 or the first cover plate 150, thereby improving the stability and reliability of the battery cell 1000.

[0095] Please refer to Figure 1 and Figure 2 In this embodiment, the first tab 140 is connected to the first electrode terminal 153 to form a first electrical connection area, and the first tab 140 and the first electrode terminal 153 are fixed by ultrasonic welding.

[0096] Ultrasonic welding utilizes high-frequency vibration waves transmitted to the surfaces of two objects to be welded. Under pressure, the surfaces rub against each other, and the heat generated by this high-frequency friction accelerates the movement of molecules at the contact surfaces, causing them to interpenetrate and thus achieving material bonding. Specifically, when the high-frequency electrical signal generated by the ultrasonic generator is converted into mechanical vibration by a transducer, the amplitude is typically between a few micrometers and tens of micrometers. The amplitude is amplified to a suitable level by an amplitude transformer and transmitted to the welding head, which then transfers the vibrational energy to the surface of the workpiece.

[0097] The first tab 140 can be made of a relatively soft material. Ultrasonic welding can form a tight connection between the first tab 140 and the first electrode terminal 153 with low contact resistance, thereby ensuring the smooth current transmission of the battery cell 1000 during charging and discharging, reducing energy loss and heat generation caused by poor contact, and helping to improve the charging and discharging efficiency and overall performance of the battery.

[0098] Compared with traditional welding methods such as electric arc welding, ultrasonic welding produces lower destructive strength. Ultrasonic welding can prevent the first tab 140 from tearing during welding, making the connection between the first tab 140 and the first electrode terminal 153 more secure, ensuring the current carrying capacity of the battery cell 1000, and improving the stability and reliability of the battery cell 1000 in use.

[0099] In some embodiments, the resistance welding fixture pressure plate 180 can be used to assist the battery cell 1000 in welding assembly, thereby improving the assembly efficiency of the battery cell 1000.

[0100] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0101] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0102] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

[0103] Although embodiments of this application have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of this application, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A battery cell, characterized in that, include: A housing, along a first direction, has a first opening at one end; A battery cell is located inside the housing. The battery cell includes a battery cell body and a first electrode tab. Along the first direction, the battery cell body has a first end face facing the first opening. The first electrode tab is disposed on the first end face. The first electrode tab includes a first segment, a second segment, and a third segment connected in sequence. The first segment is electrically connected to the battery cell body. A first cover plate is disposed on the housing and blocks the first opening. Along the first direction, the first cover plate has a bottom surface facing the cell body, and the bottom surface is spaced apart from the first end face. An electrode terminal is disposed on the first cover plate, and the electrode terminal is connected to the third segment to form a first electrical connection area; Wherein, a first bend point is formed at the connection between the first segment and the second segment, and a second bend point is formed at the connection between the second segment and the third segment. The length of the first tab between the first bend point and the second bend point is L. Along the second direction, the first cover plate has a first side and a second side that are arranged opposite to each other, and the second bend point is located between the first side and the first bend point. The distance between the second bend point and the first side is d, which satisfies: 1.2≤L / d≤6. The second direction is perpendicular to the first direction.

2. The battery cell according to claim 1, characterized in that, Along the second direction, the cell body has a first surface and a second surface arranged opposite to each other, the distance between the first surface and the second surface is t, and the distance between the first bending point and the first surface is a, satisfying: a≥t / 2.

3. The battery cell according to claim 2, characterized in that, It satisfies: 1.2≤L / d≤5.

8.

4. The battery cell according to claim 1, characterized in that, Along the second direction, the cell body has a first surface and a second surface arranged opposite to each other, the distance between the first surface and the second surface is t, and the distance between the first bending point and the first surface is a, satisfying: a < t / 2.

5. The battery cell according to claim 4, characterized in that, The value is 1.4 ≤ L / d ≤ 6.

6. The battery cell according to claim 1, characterized in that, The first electrode also includes a fourth segment, one end of the third segment is connected to the second segment, the other end of the third segment is connected to the fourth segment, and along the first direction, the fourth segment is located on the side of the third segment facing the cell body.

7. The battery cell according to claim 6, characterized in that, 1.2≤L / d≤5.

8.

8. The battery cell according to claim 1, characterized in that, The first electrical connection area includes a first welding area along the second direction, and the size of the first welding area is D1, wherein D1 satisfies: 1mm≤D1≤14mm.

9. The battery cell according to claim 1, characterized in that, The first tab is connected to the first electrode terminal to form the first electrical connection area, and the first tab and the first electrode terminal are fixed by ultrasonic welding.

10. The battery cell according to claim 1, characterized in that, The length L of the first electrode tab between the first bending point and the second bending point satisfies: 4mm ≤ L ≤ 28mm.

11. The battery cell according to claim 1, characterized in that, Along the second direction, the distance between the second bending point and the first side is d, which satisfies: 1.5mm≤d≤15mm.

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