Battery cell and battery

Abstract

The utility model discloses a battery cell and a battery. The battery cell comprises a first diaphragm belt; the second diaphragm belt is overlapped with the first diaphragm belt; the at least two first pole pieces are clamped between the first diaphragm belt and the second diaphragm belt and are arranged at intervals along the first direction; the first diaphragm belt and the second diaphragm belt respectively comprise an extension part exceeding the outer side edge of the first pole piece on the outermost side along the first direction, and the corresponding extension parts are bonded; the first pole piece, the first diaphragm belt and the second diaphragm belt form an integrated composite material belt, the composite material belt comprises a plurality of straight areas and bending areas, and the bending areas are connected with the adjacent straight areas; the composite material belt comprises a first composite area formed by bonding a first diaphragm belt, a first pole piece and a second diaphragm belt, and a non-composite area formed by not bonding the first diaphragm belt and the second diaphragm belt; the non-composite area is at least partially located in the bending area; and the second pole piece and the straight area are arranged in a crossed and laminated manner along the thickness direction of the battery cell, so that powder falling of the first pole piece is eliminated, and the covering yield of the second pole piece is improved.

Description

Technical Field

[0001] This utility model relates to the field of battery structure technology, and more specifically, to a battery cell. Furthermore, this utility model also relates to a battery comprising the aforementioned battery cell. Background Technology

[0002] Batteries, as a green, high-energy, and rechargeable chemical energy source, have wide applications in consumer electronics, new energy vehicles, and energy storage power stations. Furthermore, laminated cells are widely used in batteries due to their low internal resistance, high energy density, and long cycle life.

[0003] However, in the stacked cells of related technologies, the edges of the electrode plates are prone to powder shedding. When the active material powder from the edge of the electrode plate falls onto the separator, it can easily cause the separator to break. After the separator is broken, the positive electrode plate and the negative electrode plate come into direct contact, forming a short circuit inside the cell. This causes the cell to self-discharge, resulting in increased voltage decay.

[0004] Therefore, how to reduce electrode powder shedding is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0005] In view of this, the purpose of this utility model is to provide a battery cell that can reduce electrode powder shedding.

[0006] Another objective of this invention is to provide a battery comprising the aforementioned cells, which can reduce electrode powder shedding.

[0007] To achieve the above objectives, this utility model provides the following technical solution:

[0008] A battery cell, comprising:

[0009] First diaphragm zone;

[0010] The second diaphragm strip overlaps with the first diaphragm strip;

[0011] At least two first electrode plates are sandwiched between the first diaphragm strip and the second diaphragm strip, and are spaced apart along a first direction; wherein, the first direction is the length direction of the first diaphragm strip and the second diaphragm strip;

[0012] Along the first direction, the first diaphragm strip and the second diaphragm strip each include an extension extending beyond the outermost edge of at least one of the first electrode sheets, and the extensions of the first diaphragm strip and the extensions of the second diaphragm strip are bonded together.

[0013] The first electrode, the first diaphragm strip, and the second diaphragm strip form an integral composite strip, which includes multiple straight regions and bent regions, with the bent regions connecting adjacent straight regions.

[0014] The composite strip, along the first direction, includes a first composite area where the first diaphragm strip, the first electrode, and the second diaphragm strip are bonded together, and a non-composite area where the first diaphragm strip and the second diaphragm strip are not bonded together; the non-composite area is at least partially located within the bending area;

[0015] The second electrode and the flat region are stacked crosswise along the thickness direction of the battery cell.

[0016] Optionally, the bending region includes a second composite region where the first diaphragm strip and the second diaphragm strip are bonded together, and the non-composite region and the second composite region do not exceed the length of the bending region along the first direction.

[0017] Optionally, the first composite region is the flat region, and the non-composite region is located between the first composite region and the second composite region.

[0018] Optionally, the distance between any two adjacent first electrodes is T1, the dimension of the second composite region along the first direction is T2, and the dimension of the non-composite region as a whole along the first direction is T1-T2, where 0.1mm < (T1-T2) < 1mm.

[0019] Optionally, at least one side of the first electrode is provided with a groove; the side of the first electrode facing away from the groove is formed with a protrusion protruding from the surface of the first electrode.

[0020] Optionally, a single first electrode has at least two grooves, the distance between any two adjacent grooves along the first direction is L1, and the distance from the groove closest to the first edge of the first electrode to the first edge is T3, where L1 > T3; and / or,

[0021] Along the second direction, the distance between any two adjacent grooves is L2, and the distance from the groove closest to the second edge of the first electrode to the second edge is T4, where L2 > T4. The second direction is the width direction of the first diaphragm strip and the second diaphragm strip.

[0022] Optionally, a single first electrode has at least three grooves, and along the first direction, the distance between any one groove and the grooves on either side thereof is L3 and L4, respectively. ; and / or,

[0023] Along the second direction, the distances between any one of the grooves and the grooves on either side thereof are W1 and W2, respectively. The second direction is the width direction of the first diaphragm strip and the second diaphragm strip.

[0024] Optionally, the adhesive force of the first composite region is greater than the adhesive force of the second composite region.

[0025] Optionally, the adhesive force of the first composite region ranges from 0.2N to 0.6N; and the adhesive force of the second composite region ranges from 0.1N to 0.5N.

[0026] A battery comprising any of the aforementioned cell types.

[0027] The battery cell provided by this utility model has the following beneficial effects:

[0028] During the production of this battery cell, after the first electrode sheet is cut out, it is combined with the first separator strip and the second separator strip to form an integral composite strip. Then, the composite strip is Z-stacked with the second electrode sheet to form a Z-shaped stack.

[0029] As can be seen, this battery cell achieves a better bond between the first electrode and the first and second separator strips by pre-combining the first electrode with the first and second separator strips. This helps eliminate powder shedding from the first electrode, preventing separator damage caused by powder shedding. This reduces the risk of direct contact between the positive and negative electrodes due to separator damage, thus reducing self-discharge and consequently reducing cell voltage decay, ensuring the cell's K-value meets requirements. The cell's K-value is a parameter measuring the battery's self-discharge rate. Under certain conditions, the cell voltage decreases over time; a smaller K-value means a lower self-discharge rate, resulting in better cell performance. Therefore, the aforementioned cell structure contributes to improved cell performance. In addition, it is understood that, along the first direction, the first diaphragm strip and the second diaphragm strip each include an extension that extends beyond the outer edges of the two outermost first electrodes. The extensions of the first diaphragm strip and the extensions of the second diaphragm strip are bonded together, which improves the overall structural stability of the composite strip and avoids the first electrodes from being exposed.

[0030] Furthermore, the second electrode and the flat area are stacked crosswise along the thickness direction of the cell. That is, the composite strip and the second electrode form a Z-shaped stack through Z-stacking, ensuring that one side of the second electrode is always covered by the portion between the two adjacent first electrodes of the composite strip. This improves the coverage yield between the separator and the second electrode, helps prevent the second electrode from shifting laterally during the process, and makes the process simpler and more efficient. Moreover, this cell structure avoids the separator cutting process, thus further improving process efficiency.

[0031] The battery provided by this utility model includes the above-mentioned battery cell and has at least the beneficial effects of the above-mentioned battery cell. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this utility model or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the battery cell structure provided in a specific embodiment of the present utility model;

[0034] Figure 2 This is a schematic diagram of the composite strip structure of the battery cell;

[0035] Figure 3 This is a schematic diagram of the composite zone and the non-composite zone of the composite strip;

[0036] Figure 4 for Figure 3 A magnified view of part A in the image;

[0037] Figure 5 A schematic diagram of a structure with a circular groove for the first electrode;

[0038] Figure 6 This is a schematic diagram showing the dimensional relationship between the first electrode and the circular groove;

[0039] Figure 7 A schematic diagram of a structure with a long, narrow groove for the first electrode;

[0040] Figure 8 A schematic diagram showing the dimensional relationship between the first electrode and the elongated groove;

[0041] Figure 9 This is a schematic diagram of the battery cell structure when the first electrode plate after Z-stacking forms two first electrode tabs.

[0042] Figure label:

[0043] 1-First diaphragm band; 11-Second composite region; 12-Non-composite region; 2-First electrode; 21-Groove; 22-First electrode tab; 3-Second electrode; 31-Second electrode tab. Detailed Implementation

[0044] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0045] The core of this invention is to provide a battery cell that reduces electrode powder shedding. Another core aspect of this invention is to provide a battery comprising the aforementioned battery cell that reduces electrode powder shedding.

[0046] It should be noted that, in this embodiment of the present invention, the first direction refers to the length direction of the first diaphragm belt 1 and the second diaphragm belt, that is, the attached... Figure 2 The X-axis direction; the second direction refers to the width direction of the first diaphragm belt 1 and the second diaphragm belt, that is, the attached... Figure 2 The Y-axis direction in the diagram.

[0047] Please refer to Figure 1 and Figure 2 This utility model provides a battery cell, including a first separator strip 1, a second separator strip, a first electrode 2, and a second electrode 3. The first separator strip 1 and the second separator strip are overlapped, and the first electrode 2 is sandwiched between the first separator strip 1 and the second separator strip. The number of first electrode 2 is at least two, and all the first electrode 2 are spaced apart along a first direction. Along the first direction, the first separator strip 1 and the second separator strip each include an extension portion extending beyond the outer edge of at least one of the outermost first electrode 2. The extension portion of the first separator strip 1 and the second separator strip... The extension of the tape is bonded; and the first electrode 2, the first diaphragm tape 1, and the second diaphragm tape form an integral composite tape. The composite tape includes multiple straight areas and bent areas, with the bent areas connecting adjacent straight areas. The composite tape includes a first composite area along the first direction where the first diaphragm tape 1, the first electrode 2, and the second diaphragm tape are bonded, and a non-composite area 12 where the first diaphragm tape 1 and the second diaphragm tape are not bonded. The non-composite area 12 is at least partially located within the bent area. The second electrode 3 and the straight areas are stacked crosswise along the thickness direction of the cell.

[0048] In other words, when producing the battery cell, after cutting out the first electrode 2, the first electrode 2 is combined with the first separator belt 1 and the second separator belt to form an integral composite strip. Then, the composite strip is Z-stacked with the second electrode 3 to form a Z-shaped stack.

[0049] It is evident that by pre-combining the first electrode 2 with the first separator strip 1 and the second separator strip, this cell achieves a better bond between the first electrode 2 and the first separator strip 1 and the second separator strip. This helps eliminate powder shedding from the first electrode 2, preventing separator damage caused by powder shedding. This reduces the risk of direct contact between the positive and negative electrodes due to separator damage, reducing self-discharge and thus minimizing cell voltage decay, ensuring the cell's K-value meets requirements. The cell's K-value is a parameter measuring the battery's self-discharge rate. Under certain conditions, the cell voltage decreases over time; a smaller K-value means a lower self-discharge rate, resulting in better cell performance. Therefore, the aforementioned cell structure contributes to improved cell performance. In addition, it is understood that, along the first direction, the first diaphragm strip 1 and the second diaphragm strip respectively include extensions that extend beyond the outer edges of the two outermost first electrode sheets 2. The extensions of the first diaphragm strip 1 and the extensions of the second diaphragm strip are bonded together, which improves the overall structural stability of the composite strip and avoids the first electrode sheets from being exposed.

[0050] Furthermore, the second electrode 3 and the flat area are stacked crosswise along the thickness direction of the cell. That is, the composite strip and the second electrode 3 form a Z-shaped stack through Z-stacking, so that one side of the second electrode 3 is always covered by the portion between the two adjacent first electrodes 2 of the composite strip. This improves the coverage yield between the separator and the second electrode 3, and helps prevent the second electrode 3 from shifting laterally during the process, making the process simpler and more efficient. Moreover, this cell structure avoids the separator cutting process, thus further improving process efficiency.

[0051] It should be noted that this embodiment does not limit the specific method of compounding the first electrode 2, the first diaphragm belt 1, and the second diaphragm belt. Related technologies can be referenced. For example, the first electrode 2, the first diaphragm belt 1, and the second diaphragm belt can be compounded by heating with a hot roller.

[0052] To further improve the overall structural stability of the composite strip, in some embodiments, the bending region includes a second composite region 11 where the first diaphragm strip 1 and the second diaphragm strip are bonded together, and the non-composite region 12 and the second composite region 11 do not exceed the length of the bending region along the first direction.

[0053] In other words, the portion of the first diaphragm belt 1 and the second diaphragm belt located between any two adjacent first electrode plates 2 includes the second composite region 11. It should be noted that the second composite region 11 refers to the area where, during the composite process, the portion of the first diaphragm belt 1 and the second diaphragm belt located between any two adjacent first electrode plates 2 is subjected to a composite effect and becomes bonded; that is, the first diaphragm belt 1 and the second diaphragm belt in this region are composited to form an integral structure. The non-composite region 12 refers to the area where, during the composite process, the portion of the first diaphragm belt 1 and the second diaphragm belt located between any two adjacent first electrode plates 2 is not bonded together. For example, when the stacked first diaphragm belt 1, first electrode plate 2, and second diaphragm belt are rolled using hot rollers, due to the thickness of the first electrode plate 2, areas near the first electrode plate 2 where the first diaphragm belt 1 and the second diaphragm belt cannot be bonded together may appear. It is understandable that when the composite strip and the second electrode 3 are Z-stacked, the portion of the first diaphragm strip 1 and the second diaphragm strip located between any two adjacent first electrodes 2 forms an arc region. If there is no non-composite region 12, during Z-stacking, due to the inconsistent lengths of the inner and outer rings of the arc region, air bubbles are easily generated in the arc region. Therefore, in this embodiment, by ensuring that the non-composite region 12 and the second composite region 11 do not exceed the length of the bending area along the first direction, the non-composite region 12 and the second composite region 11 are located in the arc region, so as to avoid the generation of air bubbles in the arc region by using the non-composite region 12, and at the same time, to improve the structural stability of the arc region by using the second composite region 11.

[0054] Furthermore, in some embodiments, the first composite region is a flat region, and the non-composite region 12 is located between the first composite region and the second composite region 11.

[0055] In other words, in this embodiment, the first composite region completely overlaps with the flat region. That is, in the flat region, the first diaphragm strip 1, the first electrode 2, and the second diaphragm strip are bonded together to form the first composite region, so as to ensure the stability of the composite structure in the flat region. The non-composite region 12 serves as a transition between the first composite region and the second composite region 11.

[0056] Additionally, please refer to Figure 3 and Figure 4 In some embodiments, the distance between any two adjacent first electrodes 2 is T1, the size of the second composite region 11 along the first direction is T2, and the size of the non-composite region 12 along the first direction is T1-T2, where 0.1mm < (T1-T2) < 1mm.

[0057] In other words, by ensuring that the overall dimensions T1-T2 of the non-composite area 12 along the first direction are within the range of 0.1mm < (T1-T2) < 1mm, this embodiment effectively solves the problem of air bubbles in the arc area while ensuring the stability of the overall structure of the composite strip, avoids the increase of the internal resistance of the battery cell, and prevents black spots from appearing inside the battery cell after cyclic charging and discharging.

[0058] It is understood that the portion of the first diaphragm strip 1 and the second diaphragm strip located between any two adjacent first electrode plates 2 includes two non-composite regions 12, which are respectively located on both sides of the second composite region 11. T1-T2 is the sum of the dimensions of the two non-composite regions 12 of the first diaphragm strip 1 and the second diaphragm strip located between any two adjacent first electrode plates 2 along the first direction. In some embodiments, the dimensions of the two non-composite regions 12 of the first diaphragm strip 1 and the second diaphragm strip located between any two adjacent first electrode plates 2 along the first direction are equal, that is, the dimension of a single non-composite region 12 along the first direction is... , .

[0059] Additionally, please refer to Figure 5 and Figure 7 In some embodiments, at least one side of the first electrode 2 is provided with a groove 21.

[0060] It is understandable that by setting a groove 21 in the first electrode 2, a liquid storage tank can be formed in the groove 21, which is beneficial for the electrolyte to wet the first electrode 2, thereby increasing the charge and discharge cycle life of the battery cell.

[0061] It should be noted that this embodiment does not limit the specific shape of the groove 21 or its formation method. For example, the groove 21 can be formed on at least one side of the first electrode 2 by laser wire drilling, embossing, mechanical drilling, etc. The shape of the groove 21 can be circular (e.g., ...). Figure 5 and Figure 6 As shown), oval, oblong (as shown) Figure 7 and Figure 8 (as shown) or any other regular or irregular shape.

[0062] Furthermore, in some embodiments, the side of the first electrode 2 facing away from the groove 21 is formed with a protrusion protruding from the surface of the first electrode 2.

[0063] Understandably, the protrusions extend beyond the surface of the first electrode 2, conversely making the surface of the first electrode 2 concave to the protrusions. This facilitates electrolyte storage, allowing the electrolyte to fully wet the first electrode 2, thereby further increasing the charge-discharge cycle life of the battery cell. Furthermore, it should be noted that the protrusions can be created simultaneously with the grooves 21 using a processing technique. For example, by using an embossing method, when a groove 21 is created on one side of the first electrode 2, a corresponding protrusion is created on the other side of the first electrode 2. This process is simple and easy to implement.

[0064] Furthermore, such as Figure 5 and Figure 7 As shown, in some embodiments, a single first electrode 2 is provided with at least two grooves 21. Along the first direction, the distance between any two adjacent grooves 21 is L1, and the distance from the groove 21 closest to the first edge of the first electrode 2 to the first edge is T3, where L1 > T3; and / or, along the second direction, the distance between any two adjacent grooves 21 is L2, and the distance from the groove 21 closest to the second edge of the first electrode 2 to the second edge is T4, where L2 > T4.

[0065] It should be noted that the first edge portion refers to the edge portion of the first electrode 2 in the first direction, and the second edge portion refers to the edge portion of the first electrode 2 in the second direction. That is to say, in this embodiment, along the first direction, the distance between any two adjacent grooves 21 is greater than the distance from the outermost groove 21 to the corresponding edge, and along the second direction, the distance between any two adjacent grooves 21 is greater than the distance from the outermost groove 21 to the corresponding edge. In other words, the distribution of grooves 21 can cover the edge area of ​​the first electrode 2 as much as possible. This can ensure that there are more grooves 21 on the first electrode 2, which is more conducive to the electrolyte wetting of the first electrode 2.

[0066] In some embodiments, T3 ≥ 0 and T4 ≥ 0. It can be understood that when T3 = 0, it indicates that along the first direction, the distance from the groove 21 closest to the first edge of the first electrode 2 to the corresponding first edge is 0, meaning the groove 21 falls on the first edge of the first electrode 2. Similarly, when T4 = 0, it indicates that along the second direction, the distance from the groove 21 closest to the second edge of the first electrode 2 to the corresponding second edge is 0, meaning the groove 21 falls on the second edge of the first electrode 2. In other words, the groove 21 can fall at the edge of the first electrode 2, which is more conducive to electrolyte wetting of the first electrode 2. Moreover, through the groove 21 at the edge of the first electrode 2, the electrolyte can more easily flow from the edge of the first electrode 2 to the center of the first electrode 2.

[0067] In addition, in some embodiments, the groove 21 may also be provided on the first electrode tab 22 of the first electrode plate 2, which can change the cross-sectional shape of the first electrode tab 22, thereby improving the bending strength of the first electrode tab 22 of the first electrode plate 2 and preventing the first electrode tab 22 of the first electrode plate 2 from cracking.

[0068] Furthermore, in some embodiments, a single first electrode 2 is provided with at least three grooves 21, and along the first direction, the distance between any one groove 21 and the grooves 21 on its two sides is L3 and L4, respectively. ; and / or, along the second direction, the distances between any groove 21 and the grooves 21 on its two sides are W1 and W2, respectively. The second direction is the width direction of the first diaphragm belt 1 and the second diaphragm belt.

[0069] In other words, along the first direction, the distance between any two adjacent grooves 21 can be equal or unequal; along the second direction, the distance between any two adjacent grooves 21 can be equal or unequal. Simultaneously, along the first direction, the distance between any two adjacent grooves 21 must satisfy… The relationship, along the second direction, requires that any two adjacent spacings between grooves 21 must satisfy... The relationship is that, in this embodiment, the distance between any two adjacent grooves 21 does not have to be strictly equal, as long as L3 and L4 and W1 and W2 satisfy the above proportional relationship. This ensures that there is a suitable distance between any two adjacent grooves 21, while guaranteeing die-cutting efficiency and quality.

[0070] Furthermore, such as Figure 6 and Figure 8 As shown, in some embodiments, the thickness of the first electrode 2 is H1, the depth of the groove 21 is H2, and the distance from the bottom of the groove 21 to the end of the protrusion away from the first electrode 2 is H3, where H1 ≤ H2 + H3. , It is understandable that, for the case where the protrusion is formed by the processing technology of groove 21, H1≤H2+H3 is beneficial to ensure that groove 21 has a certain depth, thereby improving the effect of electrolyte wetting of the first electrode 2. Furthermore, for the case where the protrusion is formed by the processing technology of groove 21, there is... In this case, a portion of the groove 21 extends to the protrusion; however, when the groove 21 is formed by methods such as laser wire drilling or mechanical hole making, then... .in addition, That is, it exists. In other words, the groove 21 can be a through hole that penetrates the first electrode 2.

[0071] In addition, it is understood that in this embodiment of the present invention, the first electrode 2 can be a positive electrode or a negative electrode. When the first electrode 2 is a positive electrode, the second electrode 3 is a negative electrode; when the first electrode 2 is a negative electrode, the second electrode 3 is a positive electrode.

[0072] Additionally, it should be noted that the grooves 21 can be spaced apart along the first direction and / or the second direction, or the grooves 21 can be an integral groove extending along the first direction or the second direction.

[0073] For example, in some embodiments, the first electrode 2 is a positive electrode, and the grooves 21 are discretely distributed in both the first and second directions. In this case, the grooves 21 can be formed by embossing, and the cross-sectional shape of the grooves 21 can be circular. The first electrode 2 has at least one groove 21 distributed in both the first and second directions.

[0074] In other embodiments, the first electrode 2 is a negative electrode, and the grooves 21 are spaced apart in a first direction and are elongated grooves extending along the second direction. That is, the first electrode 2 is provided with at least one groove 21 extending along the second direction. When the number of grooves 21 is at least two, the at least two grooves 21 are spaced apart along the first direction. In this case, the grooves 21 can be formed by laser cutting, and the cross-sectional shape of the grooves 21 can be rectangular.

[0075] In addition, it should be noted that this utility model embodiment does not limit whether the second electrode 3 is provided with a groove. A groove can also be provided on the second electrode 3. The specific structure and formation method of the groove can be referred to the case where the first electrode 2 is provided with a groove 21, and will not be described again here.

[0076] In addition, in some embodiments, the adhesive force of the first composite region is greater than that of the second composite region 12.

[0077] For example, the adhesive force between the first electrode 2 and the first diaphragm strip 1 and / or between the first electrode 2 and the second diaphragm strip is greater than the adhesive force of the portions of the first diaphragm strip 1 and the second diaphragm strip located between any two adjacent first electrode 2s. This can better ensure the reliability of the connection between the first electrode 2 and the first diaphragm strip 1 and / or the second diaphragm strip, and can better prevent the diaphragm area in the arc region from breaking due to excessive bending stress.

[0078] Furthermore, in some embodiments, the adhesive force of the first composite region ranges from 0.2N to 0.6N; and the adhesive force of the second composite region 12 ranges from 0.1N to 0.5N.

[0079] In other words, the aforementioned adhesive force range between the first electrode 2 and the first diaphragm strip 1 and / or the second diaphragm strip ensures that the first electrode 2 and the first diaphragm strip 1 and / or the second diaphragm strip form a stable composite structure, ensuring the reliability of the composite of the first electrode 2, the first diaphragm strip 1, and the second diaphragm strip. Simultaneously, the aforementioned adhesive force range of the portions of the first diaphragm strip 1 and the second diaphragm strip located between any two adjacent first electrodes 2 prevents excessive bending stress in the diaphragm region of the arc-shaped area from causing breakage after the composite strip and the second electrode 3 are Z-folded.

[0080] In some embodiments, the first electrode tabs 22 of any two adjacent first electrode plates 2 are arranged in a mirror image, or the structures of any two adjacent first electrode plates 2 are completely identical.

[0081] It is understandable that when the first tabs 22 of any two adjacent first electrode sheets 2 are mirror images, after the composite strip and the second electrode sheet 3 are Z-folded, it can be ensured that the first tabs 22 of each first electrode sheet 2 overlap (e.g., Figure 1 As shown), this facilitates the connection of the first electrode tabs 22 of each first electrode sheet 2. When any two adjacent first electrode sheets 2 have the same structure, the composite strip and the second electrode sheet 3 are Z-stacked, so that the first electrode tabs 22 of all the first electrode sheets 2 are distributed in two positions, forming a stack of first electrode tabs 22 in the two positions (as shown). Figure 9 As shown in the figure, that is, after Z-stacking, the cell has two first tabs 22 with the same polarity.

[0082] In addition, it is understandable that the second electrode 3 is provided with a second electrode tab 31.

[0083] In some embodiments, one of the first electrode 2 and the second electrode 3 is a positive electrode and the other is a negative electrode, with the edge of the negative electrode extending 0.2 to 1 mm beyond the corresponding edge of the positive electrode. That is, in this embodiment, when the negative electrode completely covers the positive electrode and the edge of the negative electrode extends beyond the corresponding edge of the positive electrode within the aforementioned range, lithium plating in the battery cell can be avoided, and the areal capacity of the positive and negative electrodes can be ensured.

[0084] In addition to the aforementioned battery cell, this utility model also provides a battery that includes the battery cell disclosed in the above embodiments. For the structure of other parts of the battery, please refer to the relevant technology, which will not be repeated here.

[0085] The key point of this embodiment is that the battery uses the battery cell disclosed in any of the above embodiments, so that the battery includes at least the beneficial effects of the above-mentioned battery cell, which will not be repeated here.

[0086] It should also be noted that, in this specification, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0087] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0088] The battery cell and battery cell provided by this utility model have been described in detail above. Specific examples have been used to illustrate the principle and implementation of this utility model. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core idea of ​​this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made to this utility model without departing from the principle of this utility model, and these improvements and modifications also fall within the protection scope of this utility model.

Claims

1. A battery cell, characterized in that, include: First diaphragm zone (1); The second diaphragm strip overlaps with the first diaphragm strip (1); At least two first electrode plates (2) are sandwiched between the first diaphragm strip (1) and the second diaphragm strip, and are spaced apart along a first direction; wherein, the first direction is the length direction of the first diaphragm strip (1) and the second diaphragm strip; Along the first direction, the first diaphragm strip (1) and the second diaphragm strip each include an extension that extends beyond the outermost edge of at least one of the first electrode plates (2), and the extensions of the first diaphragm strip (1) and the second diaphragm strip are bonded together. The first electrode (2), the first diaphragm strip (1) and the second diaphragm strip form an integral composite strip, the composite strip including multiple straight areas and bent areas, the bent areas connecting adjacent straight areas; The composite strip, along the first direction, includes a first composite area where the first diaphragm strip (1), the first electrode (2), and the second diaphragm strip are bonded, and a non-composite area (12) where the first diaphragm strip (1) and the second diaphragm strip are not bonded; the non-composite area (12) is at least partially located within the bending area; The second electrode (3) and the flat region are stacked in a cross-layered manner along the thickness direction of the battery cell.

2. The battery cell according to claim 1, characterized in that, The bending region includes a second composite region where the first diaphragm strip (1) and the second diaphragm strip are bonded together, and the non-composite region (12) and the second composite region do not exceed the length of the bending region along the first direction.

3. The battery cell according to claim 2, characterized in that, The first composite region is the flat region, and the non-composite region (12) is located between the first composite region and the second composite region.

4. The battery cell according to claim 3, characterized in that, The distance between any two adjacent first electrodes (2) is T1, the size of the second composite region (11) along the first direction is T2, and the size of the non-composite region (12) as a whole along the first direction is T1-T2, 0.1mm < (T1-T2) < 1mm.

5. The battery cell according to any one of claims 1-4, characterized in that, At least one side of the first electrode (2) is provided with a groove (21), and the side of the first electrode (2) facing away from the groove (21) is formed with a protrusion protruding from the surface of the first electrode (2).

6. The battery cell according to claim 5, characterized in that, Each first electrode (2) has at least two grooves (21), the distance between any two adjacent grooves (21) along the first direction is L1, and the distance from the groove (21) closest to the first edge of the first electrode (2) to the first edge is T3, where L1 > T3; and / or, Along the second direction, the distance between any two adjacent grooves (21) is L2, the distance from the groove (21) closest to the second edge of the first electrode (2) to the second edge is T4, L2>T4, and the second direction is the width direction of the first diaphragm strip (1) and the second diaphragm strip.

7. The battery cell according to claim 5, characterized in that, Each first electrode (2) has at least three grooves (21), and along the first direction, the distance between any one groove (21) and the grooves (21) on its two sides is L3 and L4, respectively; and / or, Along the second direction, the distances between any one of the grooves (21) and the grooves (21) on both sides are W1 and W2, respectively, and the second direction is the width direction of the first diaphragm strip (1) and the second diaphragm strip.

8. The battery cell according to any one of claims 2-4, characterized in that, The adhesive force of the first composite area is greater than that of the second composite area.

9. The battery cell according to claim 8, characterized in that, The bonding strength of the first composite region ranges from 0.2N to 0.6N; the bonding strength of the second composite region ranges from 0.1N to 0.5N.

10. A battery, characterized in that, Includes the battery cell described in any one of claims 1-9.

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