battery cell

Abstract

This application discloses a battery cell, relating to the field of battery technology. The battery cell includes a housing, an electrode assembly, and a first limiting structure. The electrode assembly is disposed within the housing, and the first limiting structure is disposed at a first end of the electrode assembly and penetrates through it. The width of the electrode assembly at its first end is greater than or equal to the width of the electrode assembly in its middle portion. In the technical solution provided by this application, the first limiting structure penetrates through the electrode assembly, thereby achieving reliable fixation of the electrode assembly. This avoids cutting the electrode assembly to form tabs, thus preventing burrs and extending the battery's lifespan. Furthermore, the uncut electrode assembly increases the conductive area, thereby reducing the current density, improving overcurrent capacity, and reducing its own heat generation.

Description

Technical Field

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

[0002] In related technologies, to facilitate the folding and fixing of the tabs of the internal electrode assembly of a battery cell, the tabs are typically cut and shaped multiple times, resulting in a tab width smaller than the electrode sheet width. However, each cut increases the probability of burrs and foreign objects on the tabs. Burrs may puncture the separator or detach and flow with the electrolyte, affecting the battery's lifespan. Utility Model Content

[0003] This application proposes a battery cell that can achieve the gathering and fixing of the tabs without cutting them.

[0004] One embodiment of this application proposes a battery cell comprising: case; Electrode assemblies are disposed within the housing; A first limiting structure is disposed at the first end of the electrode assembly and extends through the electrode assembly; Wherein, the width of the electrode assembly at its first end is greater than or equal to the width of the electrode assembly at its middle portion.

[0005] In one embodiment, the first limiting structure includes two fixing parts, which are respectively disposed on opposite sides of the electrode assembly and clamp and fix the electrode assembly.

[0006] In one embodiment, the electrode assembly has a second end disposed opposite to the first end, and the width of the electrode assembly at its second end is greater than or equal to the width of the electrode assembly in its middle portion; the battery cell further includes a second limiting structure disposed at the second end and penetrating through the electrode assembly.

[0007] In one embodiment, the second limiting structure includes a third clamping member and a fourth clamping member, wherein a portion of one or both of the third clamping member and the fourth clamping member penetrates the electrode assembly and is connected.

[0008] In one embodiment, the electrode assembly includes: The first electrode includes a first electrode body and a first electrode tab connected to the first electrode body; a first notch or a first through hole is formed on the first electrode tab; The second electrode includes a second electrode body and a second electrode tab connected to the second electrode body; a second notch or a second through hole is formed on the second electrode tab; the polarity of the second electrode is opposite to that of the first electrode. A diaphragm is disposed between the first electrode and the second electrode; The width of the first electrode tab is greater than or equal to the width of the first electrode body; the width of the second electrode tab is greater than or equal to the width of the second electrode body.

[0009] In one embodiment, the first limiting structure includes a first clamping member and a second clamping member. The first clamping member has a first protrusion facing the second clamping member, and the second clamping member has a second protrusion facing the first clamping member. The first protrusion and the second protrusion are connected, and at least a portion of the first protrusion and the second protrusion are accommodated in the first notch or the first through hole.

[0010] In one embodiment, one of the first boss and the second boss is provided with a snap-fit ​​protrusion, and the other is provided with a snap-fit ​​hole, wherein the snap-fit ​​protrusion is snapped into and limited within the snap-fit ​​hole; or The first boss and the second boss are connected by an adjusting screw.

[0011] In one embodiment, the second limiting structure includes a third clamping member and a fourth clamping member. The third clamping member has a third protrusion facing the fourth clamping member, and the fourth clamping member has a fourth protrusion facing the third clamping member. The third protrusion and the fourth protrusion are connected, and at least a portion of the third protrusion and the fourth protrusion are accommodated in the second notch or the second through hole.

[0012] In one embodiment, the ratio of the width of the first limiting structure to the width of the housing is 0.86 to 0.98; and / or The ratio of the height of the first limiting structure to the height of the housing is between 0.0025 and 0.0139.

[0013] In one embodiment, the battery cell further includes an electrode assembly, which includes a positive electrode and a negative electrode. The positive electrode is disposed at the first end, and the negative electrode is disposed at the opposite end of the first end. The electrode assembly is connected to the positive electrode and the negative electrode.

[0014] This application establishes a first limiting structure that penetrates the electrode assembly, thereby ensuring that the first limiting structure can retract and fix the ends of the electrode assembly in the full-tab electrode assembly. Specifically, the first limiting structure is located at the first end of the electrode assembly and penetrates the electrode assembly to reliably fix the first end of the electrode assembly. The first limiting structure applies a clamping force to the gap between the first ends of the electrode assembly to retract the ends of the electrode assembly. In this way, cutting of the electrode assembly can be avoided, thereby preventing the generation of burrs and extending the battery's lifespan. Moreover, the width of the electrode assembly at its first end is greater than or equal to the width of the electrode assembly in its middle section. The uncut electrode assembly increases the conductive area, thereby reducing the current density and reducing its own heat generation. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments or prior art of this application, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of a single battery cell provided in this application; Figure 2 for Figure 1 Cross-sectional view of a single battery cell; Figure 3 An exploded view of the first embodiment of the electrode in a single battery cell; Figure 4 An exploded view of the second embodiment of the electrode in a single battery cell; Figure 5 This is a schematic diagram of the exploded structure of the first limiting structure; Figure 6 This is a cross-sectional view of one end of a single battery cell; Figure 7 This is a schematic diagram of the exploded structure of one embodiment of a battery cell.

[0017] Explanation of icon numbers: 100. Battery cell; 1. Casing; 11. First cover plate; 111. Positive electrode post; 12. Second cover plate; 121. Negative electrode post; 2. Electrode assembly; 2a. First end; 2b. Second end; 21. First electrode plate; 211. First electrode plate body; 212. First tab; 213. First notch; 214. First through hole; 22. Second electrode plate; 221. Second electrode plate body; 222. Second tab; 223. Second notch; 224. Second through hole; 3. First limiting structure; 31. First clamping member; 311. First boss; 3111. Snap-fit ​​protrusion; 31a. Hollowed-out part; 32. Second clamping member; 321. Second boss; 3211. Snap-fit ​​hole; 4. Second limiting structure; 41. Third clamping member; 42. Fourth clamping member; 5. Adapter piece; 6. Mylar membrane. Detailed Implementation

[0018] The technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings of several embodiments. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0019] It should be noted that if multiple embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0020] Furthermore, if multiple embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text implies three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0021] In related technologies, in order to facilitate the gathering and fixing of the tabs of the electrode assembly inside the battery cell, the tabs are usually cut and shaped multiple times so that the width of the tabs is smaller than the width of the electrode sheet. However, each cut will generate burrs and metal dust at the edge of the foil. These burrs may puncture the separator or flow into the battery with the electrolyte, forming micro-short circuit channels, which will lead to increased self-discharge, accelerated capacity decay, and even safety hazards. At the same time, the foreign matter falling off during the cutting process also increases the complexity of dust removal and inspection processes, increasing manufacturing costs and quality risks.

[0022] Moreover, cutting the tabs requires an additional manufacturing step, which extends the product manufacturing time and increases production costs.

[0023] To address the aforementioned issues, this application proposes a battery cell 100 that eliminates the need for cutting the electrode assembly 2 while ensuring the folding and fixation of the ends of the electrode assembly 2, thereby solving the aforementioned technical problems.

[0024] Please see Figure 1 In one embodiment of this application, the battery cell 100 includes a housing 1, an electrode assembly 2, and a first limiting structure 3. The electrode assembly 2 is disposed inside the housing 1, and the first limiting structure 3 is disposed at the first end 2a of the electrode assembly 2 and passes through the electrode assembly 2. The width of the electrode assembly 2 at its first end 2a is greater than or equal to the width of the electrode assembly 2 in its middle portion.

[0025] Understandably, please refer to Figure 3 and combined Figure 4 The first end 2a of electrode assembly 2 is also the lead-out end of electrode assembly 2, which is the current conduction region. The middle part of electrode assembly 2, also known as the central region, is the electrochemical reaction region, coated with an active material that participates in the electrochemical reaction. The first end 2a is a blank area. The width of the first end 2a of electrode assembly 2 is greater than or equal to the width of the central part of electrode assembly 2, meaning that electrode assembly 2 in this design does not need to be cut, thus avoiding burrs generated by cutting.

[0026] This application provides a first limiting structure 3 that penetrates the electrode assembly 2, thereby ensuring that the first limiting structure 3 can retract and fix the end of the electrode assembly in the tab electrode assembly 2. Specifically, the first limiting structure 3 is located at the first end 2a of the electrode assembly 2 and penetrates the electrode assembly 2 to reliably fix the first end 2a of the electrode assembly 2. The first limiting structure 3 applies a clamping force to the gap between the first ends 2a of the electrode assembly 2 to retract the end of the electrode assembly 2. In this way, cutting of the electrode assembly 2 can be avoided, thereby preventing the generation of burrs and extending the battery's lifespan.

[0027] In an optional embodiment, the first limiting structure 3 includes two fixing parts, which are respectively disposed on opposite sides of the electrode assembly 2. The two fixing parts together clamp the electrode assembly 2 located between them and form a fixation. The two fixing parts can be opposite magnets, which clamp and fix the electrode assembly 2 by magnetic force; or they can be two fixing plates that clamp and fix the electrode assembly 2 by snapping, bonding or other means. This application does not limit this.

[0028] In another embodiment of this application, the positive and negative electrodes of the electrode assembly 2 are led out from opposite sides of the housing 1. The electrode assembly 2 has a second end 2b at the end away from the first end 2a, and the second end 2b is also a blank area. The width of the electrode assembly 2 at its second end 2b is greater than or equal to the width of the electrode assembly 2 in its middle portion. The battery cell 100 also includes a second limiting structure 4, please refer to further details. Figure 7 The second limiting structure 4 is disposed at the second end 2b and penetrates the electrode assembly 2. The second limiting structure 4 is completely identical in structure to the first limiting structure 3, and can be referred to the above detailed description of the first limiting structure 3, which will not be repeated here.

[0029] Because the battery of this application adopts a full-tab design, the first tab 212 and the second tab 222 with opposite polarities are led out from opposite ends of the casing 1, thus eliminating the need for cutting the first tab 212 and the second tab 222. The electrode assembly 2 is obtained by stacking the first electrode 21, the separator, and the second electrode 22. The first electrode 21 includes a first electrode body 211 and a first tab 212 connected to the first electrode body 211; the second electrode 22 includes a second electrode body 221 and a second tab 222 connected to the second electrode body 221. The first limiting structure 3 is used to cooperate and fix the first tab 212, and the second limiting structure 4 is used to cooperate and fix the second tab 222.

[0030] In addition, the first tab 212 and the second tab 222 are located at opposite ends of the housing 1, resulting in a more uniform electric field distribution and a shorter and symmetrical current path. This can significantly reduce internal resistance and temperature rise, and improve rate performance. At the same time, the wires coming out at both ends provide ample bending space for the first tab 212, avoiding the risk of short circuits caused by congestion on the same side. It also simplifies the cover plate wiring and insulation design, is compatible with the full tab no-cutting process, eliminates the hidden dangers of burrs caused by cutting, and takes into account high energy density, high safety and high manufacturing efficiency.

[0031] In an optional embodiment, the first limiting structure 3 is taken as an example. The first limiting structure 3 is mainly divided into two parts: a first clamping member 31 and a second clamping member 32. The first clamping member 31 and the second clamping member 32 are respectively disposed on opposite sides of the first electrode ear 212, so that the first clamping member 31 and the second clamping member 32 can clamp the first electrode ear 212 from both sides to realize the folding and fixing of the multi-electrode ear. It should be noted that the first clamping member 31 and the second clamping member 32 can be strip-shaped, straight plate-shaped, or arc-shaped plate-shaped. This application does not limit the shape of the first clamping member 31 and the second clamping member 32. In one embodiment of this application, the first clamping member 31 and the second clamping member 32 are both long rectangular prisms. For details, please refer to further reference. Figure 1 The lengths of the first clamping member 31 and the second clamping member 32 are adapted to the width of the electrode and are slightly smaller than the inner width of the housing 1, so as to ensure that the two ends of the first clamping member 31 and the second clamping member 32 can respectively abut against the side plate of the housing 1, and avoid them from shaking along the width direction of the electrode inside the housing 1.

[0032] Furthermore, one plane of the first clamping member 31 and the second clamping member 32 abuts against the electrode assembly, while the opposite plane abuts against the battery cover (which can be the first cover 11 or the second cover 12), thus restricting their degrees of freedom along the length of the electrode. In summary, the first clamping member 31 and the second clamping member 32 are reliably fixed and cannot move within the housing 1, thereby ensuring their stability when clamping and fixing the first electrode tab 212, preventing the electrode from shaking or shifting within the housing 1. This not only simplifies the assembly process, reduces the number of parts and costs, but also ensures that the first electrode tab 212 is always in a controlled and uniform clamping state, providing a constant position and stable pressure for subsequent welding, thereby improving welding consistency, reducing the risk of incomplete welds, and further enhancing the mechanical reliability and electrical safety of the battery cell.

[0033] Furthermore, the first clamping member 31 and the second clamping member 32 are connected through a recessed portion formed on the first tab 212, which creates a channel for the connection between the first clamping member 31 and the second clamping member 32. It should be noted that the first clamping member 31 and the second clamping member 32 may be connected by parts of their structures extending into the recessed portion; alternatively, a portion of the first clamping member 31 may extend into the recessed portion and extend out from one side of the second clamping member 32 to connect with its body; or a portion of the second clamping member 32 may extend into the recessed portion and extend out from one side of the first clamping member 31 to connect with its body. This application does not impose any limitations on this. In one embodiment of this application, the first clamping member 31 has a first protrusion 311 facing the second clamping member 32, and correspondingly, the second clamping member 32 has a second protrusion 321 facing the first clamping member 31. For further details, please refer to [the relevant documentation / reference needed]. Figure 5The first boss 311 and the second boss 321 each extend into the half position of the recess, thereby achieving the connection between the first boss 311 and the second boss 321, and thus ensuring the reliable fixation of the first clamping member 31 and the second clamping member 32.

[0034] By setting a first limiting structure 3 and providing a clearance portion on the first tab 212, the first clamping member 31 and the second clamping member 32 in the first limiting structure 3 can be connected and fixed through the clearance portion, thereby achieving the folding and fixing of the first tab 212 in the full-tab battery cell 100. Specifically, the first limiting structure 3 includes a first clamping member 31 and a second clamping member 32 respectively disposed on opposite sides of the first tab 212. Parts of the structure of the first clamping member 31 and / or part of the structure of the second clamping member 32 are connected through the clearance portion provided on the first tab 212, thereby ensuring reliable fixing of the first clamping member 31 and the second clamping member 32. The first clamping member 31 and the second clamping member 32 apply clamping force to the gap between them to fold each first tab 212. By providing a clearance portion on the first tab 212 to form a connection channel between the first clamping member 31 and the second clamping member 32, reliable fixing of the first tab 212 is achieved. This avoids cutting the first tab 212, thus preventing burrs and extending battery life. Furthermore, the uncut first tab 212 increases the conductive area, thereby reducing current density and heat generation.

[0035] Similarly, the second limiting structure 4 includes a third clamping member 41 and a fourth clamping member 42. Both the third clamping member 41 and the fourth clamping member 42 are disposed at the second end 2b of the electrode assembly 2, and are located on opposite sides of the electrode assembly 2. The second end 2b of the electrode assembly 2 is also the negative electrode tab lead-out end. The second electrode tab 222 has a clearance portion, which can be a second notch 223 or a second through hole 224. The third clamping member 41 has a third protrusion facing the fourth clamping member 42, and the fourth clamping member 42 has a fourth protrusion facing the third clamping member 41. The third and fourth protrusions are accommodated in the clearance portion and are connected by one of the following methods: snap-fit, screw-fit, or adhesive. Since the specific structure and installation method of the second limiting structure 4 are the same as those of the first limiting structure 3, they will not be described again here.

[0036] It should be noted that the clearance part can be a through hole, or a mounting notch or through groove. This application does not limit the specific shape or size of the clearance part. This application proposes two different clearance part structures to meet the differentiated needs of batteries.

[0037] First Embodiment Please see Figure 3In the first embodiment, the clearance portion is a notch. Each first tab 212 has a first notch 213, and each second tab 222 has a second notch 223. Taking the first notch 213 as an example, the first notch 213 is directly punched into shape at the edge of the first tab 212, which is simple to process, retains the integrity of the foil material, and avoids additional dust. The open slot structure allows the clamping component to slide in quickly from the side, shortening the assembly cycle. It can also accommodate the thickness variation of the first tabs 212 with different layers, providing continuously adjustable clamping force. At the same time, the slotted clearance portion allows for slight displacement during vibration or thermal expansion, which can relieve stress and prevent tearing at the root of the first tab 212, taking into account both process simplicity, reliable connection, and long-term mechanical durability. The shape of the first notch 213 can be a square slot or an arc slot, and this application does not limit it. The structure of the second notch 223 is completely the same as that of the first notch 213, and will not be described again here.

[0038] Second Embodiment Please see Figure 4 In the second embodiment, the clearance part is a first through hole 214. Each first electrode tab 212 and second electrode tab 222 is provided with a first through hole 214. The first through hole 214 is a closed structure, with the clamping boss passing through and being uniformly surrounded by the hole wall, resulting in stronger shear and torsion resistance and no risk of slippage under vibration or welding impact. The hole position can be completed in one go by high-speed punching after coating and before winding, with neat edges and no burrs, eliminating the need for subsequent powder removal process. The first through hole 214 also blocks the lateral tearing propagation path of the first electrode tab 212, improving mechanical reliability, while ensuring a more uniform current density distribution, taking into account both the safety and high strength of the first electrode tab 212. The shape of the first through hole 214 can be a square hole or an arc hole, and this application does not limit it in this regard.

[0039] In one embodiment of this application, the first clamping member 31 is connected to the second clamping member 32 via a first protrusion 311 and a second protrusion 321. It should be noted that the first protrusion 311 and the second protrusion 321 can be connected by adhesive bonding, snap-fit, screw connection, or other methods. This application does not limit this connection. In one embodiment of this application, the first protrusion 311 is provided with a snap-fit ​​protrusion 3111, and the second protrusion 321 is provided with a snap-fit ​​hole 3211. For further details, please refer to [the relevant documentation / reference]. Figure 5 The snap-fit ​​protrusion 3111 is inserted into the snap-fit ​​hole 3211 to form an inverted snap-fit. The snap-fit ​​is self-locking by utilizing the elastic deformation of the plastic, and the assembly can be completed in one go without additional tools. The inverted bevel provides insertion guidance, and the straight surface bears the pull-out resistance. It can withstand vibration, thermal expansion and contraction and the impact of welding claws without loosening, which significantly improves the fixation reliability. This method reduces material and labor costs, avoids damage to the first tab 212 by high temperature or chemical contamination, and enables disassembly and maintenance, taking into account production efficiency, connection strength and battery life cycle safety.

[0040] In another embodiment, both the first boss 311 and the second boss 321 are provided with threaded holes, and the internal threads of the two threaded holes have opposite directions of rotation. The first limiting structure 3 also includes a screw rod, which passes through the two threaded holes in sequence and is fixed together by rotation. The two ends of the screw rod are respectively provided with external threads with opposite directions of rotation. After being inserted into the opposite threaded holes of the first and second bosses 321, the two bosses can be brought together synchronously by rotating the screw rod with one hand, clamping and self-locking the first tab 212. The opposite thread structure generates opposite torques under vibration or thermal expansion and contraction, which cancel each other out and prevent loosening. No additional spring pads or adhesive layers are required. Disassembly and assembly only require a slight rotation in both directions. The operating space is small and it can be reused repeatedly, ensuring constant clamping force while also taking into account later maintenance.

[0041] In the above embodiments, the connection method of the first protrusion 311 and the second protrusion 321 and the specific shape of the avoidance part can be adapted to actual needs. Multiple implementations of the avoidance part and multiple implementations of the first protrusion and the second protrusion can be combined to obtain new implementations.

[0042] In the technical solution of this application, the first clamping member 31 and the second clamping member 32 not only serve to gather and fix the first electrode tab 212, but also support the first electrode 21 and the second electrode 22. While the first clamping member 31 and the second clamping member 32 clamp the first electrode tab 212 from both sides, their upper and lower planes respectively abut against the cover plate of the electrode and the battery, forming a three-point support structure. The weight of the electrode and the vibration load are directly transferred to the cover plate through the clamping member, avoiding the deformation of the root of the first electrode tab 212 under force, and realizing the integration of mechanical limiting and electrical insulation of the electrode.

[0043] In view of this, the first clamping member 31 and the second clamping member 32 need to be manufactured using insulating materials. It should be noted that the materials of the first clamping member 31 and the second clamping member 32 can be polypropylene (PP), polycarbonate (PC), or other chemically stable materials that do not react with the electrolyte and have good insulating properties. This application does not limit this. In this embodiment, polypropylene is selected as the material of the first clamping member 31 and the second clamping member 32. Polypropylene has a low density, which can avoid excessively increasing the weight of the product. It also has excellent resistance to electrolyte swelling, which can provide long-term stable clamping and insulation for the first tab 212. Its elastic modulus is moderate, so it is not easy to crack when snapped or screwed, and it can absorb vibration with slight deformation. It has low raw material cost and short injection molding cycle, and has the advantages of being lightweight, safe and economical.

[0044] To further reduce the weight of individual battery cells and achieve lightweighting, the first clamping member 31 has a hollow portion 31a, or the second clamping member 32 has a hollow portion 31a, or both have hollow portions 31a. In this embodiment, to ensure the balance of battery weight, both the first clamping member 31 and the second clamping member 32 have hollow portions 31a. For details, please refer to further reading. Figure 5 The hollowed-out portion 31a, while maintaining clamping rigidity and insulation distance, significantly reduces redundant material, thereby lowering the weight of the clamping component and achieving lightweighting of the battery cell, thus increasing energy density. Simultaneously, the hollowed-out structure shortens injection molding cooling time and reduces material usage, directly lowering unit cost and molding cycle. Furthermore, the symmetrical arrangement ensures a balanced center of gravity, preventing vibration and eccentricity, thus balancing lightweighting, cost reduction, and structural reliability. Further, by providing the hollowed-out portion 31a with its opening facing the cover plate at the battery end, the alignment and engagement of the snap-fit ​​protrusion 3111 and the snap-fit ​​hole 3211 are facilitated.

[0045] In the technical solution of this application, in order to ensure the reliability of the connection between the first clamping member 31 and the second clamping member 32, the body of the first clamping member 31 and the first boss 311 are integrally formed, and the body of the second clamping member 32 and the second boss 321 are integrally formed. The integral forming eliminates the need for secondary assembly or welding, and completely eliminates the risks of interface loosening, stress concentration and electrolyte infiltration between the first boss 311, the second boss 321 and the clamping member body. This allows the clamping and screwing loads to be directly borne by the whole piece of material, resulting in higher connection strength and more stable dimensional accuracy. At the same time, it reduces the number of parts and tooling processes, and lowers manufacturing costs.

[0046] The electrode assembly 2 in the battery cell 100 proposed in this application includes a first electrode 21 and a second electrode 22 with opposite polarities, and a separator. For example, in one embodiment of this application, the first electrode 21 is a positive electrode, and the second electrode 22 is a negative electrode. The first electrode 21 has a first tab 212, and the second electrode 22 has a second tab 222. The first tab 212 is a positive tab, and the second tab 222 is a negative tab. Since the first tab 212 and the second tab 222 of the battery cell 100 adopt a full-tab design, they are respectively located at opposite ends of the battery cell 100. A separator is provided between the first electrode 21 and the second electrode 22. The separator is located between the positive and negative electrodes, achieving electronic insulation and ion conduction. The microporous structure of the separator blocks direct electron passage, preventing short circuits, while allowing lithium ions in the electrolyte to migrate freely during charging and discharging, forming a current loop. When the separator shrinks or breaks due to heat, it automatically closes or increases its impedance, delaying the spread of thermal runaway. It is a core barrier for battery safety and lifespan. The first electrode 21, the separator, and the second electrode 22 are alternately stacked to obtain the aforementioned battery cell 100.

[0047] Taking the first limiting structure 3 as an example, the width of the first limiting structure 3 (i.e., the dimension along the direction perpendicular to the large surface of the shell 1) is 43mm~83mm, and the width of the adapting shell 1 is 50mm~85mm. The ratio of the width of the first limiting structure 3 to the width of the shell 1 is 0.86~0.98. This ensures the reliability of the installation of the first limiting structure 3. Furthermore, the height of the first limiting structure 3 (i.e., the dimension along the direction perpendicular to the cover plate) is 5mm~18mm, and the height of the adapting shell 1 is 1300mm~2000mm. The ratio of the height of the first limiting structure 3 to the height of the shell 1 is 0.0025 to 0.0139. The second limiting structure 4 is similar and will not be described in detail here.

[0048] The battery cell 100 also includes a positive electrode post 111 and a negative electrode post 121. For details, please refer to further information. Figure 7 The positive electrode post 111 and the negative electrode post 121 are located on opposite sides of the housing 1, that is, close to the first end 2a and the second end 2b of the electrode assembly 2, respectively. The positive electrode post 111 is disposed through the first cover plate 11 of the housing 1, and the negative electrode post 121 is disposed through the second cover plate 12 of the housing 1. The battery cell 100 is disposed inside the housing 1. The first tab 212 is connected to the positive electrode post 111, and the second tab 222 is connected to the negative electrode post 121. The specific structure of the battery cell 100 is as described in the above embodiments. Since this battery cell adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0049] It is understood that the battery cell 100 includes multiple electrode assemblies 2, which are alternately stacked in the order of first electrode 21, separator, and second electrode 22. The first tabs 212 of all first electrode 21 are located at one end of the first cover plate 11, and the second tabs 222 of all second electrode 22 are located at one end of the second cover plate 12. All first tabs 212 on the same side are gathered and fixed by a first clamping member 31 and a second clamping member 32. Correspondingly, all second tabs 222 on the other side are also gathered and fixed by another first clamping member 31 and another second clamping member 32. To achieve insulation between the battery cell 100 and the metal casing 1, a Mylar film 6 is wrapped around the battery cell 100. For details, please refer to further documentation. Figure 7 Mylar membrane 6 is wrapped around the outer periphery of the battery cell 100, serving as secondary insulation, dustproofing, and mechanical protection. Mylar membrane 6 has the characteristics of being resistant to electrolyte, high temperature, and high breakdown voltage, which can block potential short circuits between the tab and the casing 1, and between the tabs. At the same time, it has good toughness and thinness, which not only prevents metal burrs from puncturing, but also takes up almost no volume, which helps to improve energy density and extend battery life.

[0050] In one embodiment of the battery cell proposed in this application, an adapter piece 5 is also provided. The adapter piece 5 connects the first tab 212 and the positive terminal 111, and another adapter piece 5 connects the second tab 222 and the negative terminal 121. Taking the adapter piece connected to the first tab 212 as an example, the adapter piece 5 is sandwiched between the first tab 212 and the positive terminal 111, transforming the multi-layer flexible foil material into a rigid terminal in one step, significantly reducing the difficulty of ultrasonic welding and improving the consistency of the solder joints; its large-area transition cross section can disperse the current density, reduce heat generation, and buffer vibration and thermal expansion displacement, avoiding fatigue fracture at the root of the first tab 212, thus achieving a low internal resistance, high reliability, and long lifespan electrical connection. The arrangement of the adapter piece 5 between the second tab 222 and the negative terminal 121 can refer to the specific structure of the adapter piece 5 on the first tab 212 described above, and will not be repeated here.

[0051] The above description is merely an exemplary embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made based on the technical concept of this application and the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A battery cell, characterized in that, include: Shell (1); Electrode assembly (2) is disposed within the housing (1); A first limiting structure (3) is disposed at the first end (2a) of the electrode assembly (2) and penetrates the electrode assembly (2); Wherein, the width of the electrode assembly (2) at its first end (2a) is greater than or equal to the width of the electrode assembly (2) in its middle portion.

2. The battery cell as described in claim 1, characterized in that, The first limiting structure (3) includes two fixing parts, which are respectively disposed on opposite sides of the electrode assembly (2) and clamp and fix the electrode assembly (2).

3. The battery cell as described in claim 1, characterized in that, The electrode assembly (2) has a second end (2b) disposed opposite to the first end (2a), and the width of the electrode assembly (2) at its second end (2b) is greater than or equal to the width of the electrode assembly (2) in its middle portion; the battery cell further includes a second limiting structure (4), which is disposed at the second end (2b) and penetrates the electrode assembly (2).

4. The battery cell as described in claim 3, characterized in that, The second limiting structure (4) includes a third clamping member (41) and a fourth clamping member (42), wherein a portion of one or both of the third clamping member (41) and the fourth clamping member (42) penetrates the electrode assembly (2) and is connected.

5. The battery cell as described in claim 3, characterized in that, The electrode assembly (2) includes: The first electrode includes a first electrode body (211) and a first electrode tab (212) connected to the first electrode body (211); a first notch (213) or a first through hole (214) is provided on the first electrode tab (212); The second electrode includes a second electrode body (221) and a second electrode tab (222) connected to the second electrode body (221); a second notch (223) or a second through hole (224) is formed on the second electrode tab (222); the polarity of the second electrode is opposite to that of the first electrode. A diaphragm is disposed between the first electrode and the second electrode; The width of the first electrode tab (212) is greater than or equal to the width of the first electrode body (211); the width of the second electrode tab (222) is greater than or equal to the width of the second electrode body (221).

6. The battery cell as described in claim 5, characterized in that, The first limiting structure (3) includes a first clamping member (31) and a second clamping member (32). The first clamping member (31) is provided with a first boss (311) facing the second clamping member (32), and the second clamping member (32) is provided with a second boss (321) facing the first clamping member (31). The first boss (311) and the second boss (321) are connected. At least a portion of the first boss (311) and the second boss (321) are accommodated in the first notch (213) or the first through hole (214).

7. The battery cell as described in claim 6, characterized in that, One of the first boss (311) and the second boss (321) is provided with a snap-fit ​​protrusion (3111), and the other is provided with a snap-fit ​​hole (3211), wherein the snap-fit ​​protrusion (3111) is snapped into and limited within the snap-fit ​​hole (3211); or The first boss (311) and the second boss (321) are connected by an adjusting screw.

8. The battery cell as described in claim 5, characterized in that, The second limiting structure (4) includes a third clamping member (41) and a fourth clamping member (42). The third clamping member (41) has a third protrusion facing the fourth clamping member (42), and the fourth clamping member (42) has a fourth protrusion facing the third clamping member (41). The third protrusion and the fourth protrusion are connected, and at least a portion of the third protrusion and the fourth protrusion are accommodated in the second notch (223) or the second through hole (224).

9. The battery cell according to any one of claims 1 to 4, characterized in that, The ratio of the width of the first limiting structure (3) to the width of the housing (1) is 0.86 to 0.98; and / or The ratio of the height of the first limiting structure (3) to the height of the housing (1) is 0.0025 to 0.0139.

10. The battery cell according to any one of claims 1 to 4, characterized in that, The battery cell also includes an electrode assembly, which includes a positive electrode (111) and a negative electrode (121). The positive electrode (111) is disposed at the first end (2a), and the negative electrode (121) is disposed at the opposite end of the first end (2a). The electrode assembly (2) is connected to the positive electrode (111) and the negative electrode (121).

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