Pole piece assembly, battery cell and battery
By setting up a communication hole in the pole plate assembly to communicate with the external environment, the problem of poor fluidity of the electrolyte in the closed-mouth thermal composite process is solved, the battery baking efficiency and the battery cell wetting effect are improved, the battery cycle life is extended and the short circuit risk is reduced.
Patent Information
- Application Number
- CN202421765503.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-24
- Publication Date
- 2025-07-04
- Estimated Expiration
- 2034-07-24
AI Technical Summary
In existing batteries, due to the closed-mouth thermal composite process, the electrolyte has poor fluidity and is difficult to immerse the electrode sheet, which affects the battery's capacity test life and lithium ion transmission path, resulting in a degradation of battery performance.
A communication hole is provided in the electrode plate assembly to communicate with the external environment, and an electrolyte is entered through the communication hole to improve fluidity and wetting effect. A closed-mouth thermal composite process is adopted to maintain the sealing property of the diaphragm.
It improves the baking efficiency of the electrode sheet and the fluidity of the electrolyte, enhances the wetting effect of the electrode sheet, improves the activation degree of the battery cell and cycle life, and is compatible with special-shaped electrode sheets, avoiding the risk of short circuit.
Smart Images
Figure CN223066236U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of batteries, in particular to an electrode sheet assembly, an electric core and a battery. Background Art
[0002] In the prior art, the thermal composite lamination process is often divided into open thermal composite and closed thermal composite. In the open thermal composite, the middle area of the electrode sheet and the separator is hot-pressed to bond the electrode sheet and the separator, so that the four peripheral edges are in an open state. However, the open thermal composite will affect the life of the battery during the formation test. Therefore, the existing batteries mainly adopt the closed thermal composite.
[0003] In the closed thermal composite process, the edge of the separator is hot-pressed to confine the electrode sheet in a closed chamber, and there is no adhesion between the hot-pressed electrode sheet and the separator. However, since the edge of the separator is in a closed state, it is difficult for the electrolyte to infiltrate into the electrode sheet, and the fluidity of the electrolyte is poor. Summary of the Utility Model
[0004] The utility model aims to solve at least one of the technical problems existing in the prior art. For this purpose, the utility model provides an electrode sheet assembly, which connects the accommodation cavity where the electrode sheet is located with the external environment by providing communication holes, so as to improve the fluidity of the electrolyte and the infiltration effect of the electrode sheet.
[0005] The utility model also provides an electric core having the above electrode sheet assembly.
[0006] The utility model also provides a battery having the above electric core.
[0007] The electrode sheet assembly according to the first aspect embodiment of the utility model includes:
[0008] An electrode sheet;
[0009] A first separator located on one side of the electrode sheet in the thickness direction;
[0010] A second separator located on the other side of the electrode sheet in the thickness direction, the second separator is connected to the edge of the first separator and defines a hot-pressing area, and an accommodation cavity for accommodating the electrode sheet is formed between the first separator and the second separator;
[0011] Wherein, there is a first gap between the edge of the electrode sheet and the hot-pressing area, and at least one of the first separator and the second separator is provided with a communication hole. Along the projection on the plane where the electrode sheet is located in the thickness direction, at least part of the projection area of the communication hole falls into the projection area of the first gap.
[0012] The electrode sheet assembly according to the embodiment of the utility model has at least the following beneficial effects:
[0013] In this application, by providing communication holes, the accommodation cavity where the electrode sheet is located is communicated with the external environment. When the electrode sheet assembly enters the baking process, the moisture in the electrode sheet can be better discharged, which is beneficial to improving the baking efficiency. In addition, in the liquid injection process, the electrolyte can enter the accommodation cavity through the communication holes, and the fluidity of the electrolyte is good, so the wetting effect of the electrode sheet is good, the activation degree of formation is higher, and it is beneficial to improve the cycle life of the battery cell.
[0014] According to some embodiments of the present utility model, in the projection of the communication hole on the electrode sheet along the thickness direction, a part of the projection area of the communication hole is located within the projection area of the first gap, and the remaining part is located within the projection area of the hot pressing area.
[0015] According to some embodiments of the present utility model, along the circumferential direction of the electrode sheet assembly, the hot pressing area includes alternately arranged main body parts and recessed parts, the distance from the recessed part to the electrode sheet is less than the distance from the main body part to the electrode sheet, and the communication hole is arranged corresponding to the recessed part, so that the distance from the communication hole to the electrode sheet is greater than the distance from the main body part to the electrode sheet.
[0016] According to some embodiments of the present utility model, the difference between the distance from the main body part to the electrode sheet and the distance from the recessed part to the electrode sheet is set as the recess depth D, the distance from the edge of the hot pressing area to the electrode sheet is set as the hot pressing distance L, and the recess depth D and the hot pressing distance L have the following relationship: 2D ≤ L.
[0017] According to some embodiments of the present utility model, along the circumferential direction of the electrode sheet assembly, the hot pressing area is continuous;
[0018] Alternatively, along the circumferential direction of the electrode sheet assembly, the hot pressing areas are not connected, and a circulation area is defined between adjacent hot pressing areas, and the ratio of the length of the hot pressing area to the length of the circulation area is in the range of 10 to 15.
[0019] According to some embodiments of the present utility model, the communication hole is a round hole, the aperture of the round hole is 0.22 mm to 0.5 mm, and on the same first separator or the same second separator, the interval between two adjacent round holes is five to ten times the aperture.
[0020] According to the battery cell of the second aspect embodiment of the present utility model, a plurality of electrode sheet assemblies as described in any one of the above embodiments;
[0021] Wherein, the electrode sheet of the electrode sheet assembly is a positive electrode sheet, the battery cell further includes a plurality of negative electrode sheets, the electrode sheet assembly and the negative electrode sheets are stacked, and along the stacking direction, the negative electrode sheets and the electrode sheet assembly are alternately arranged;
[0022] Alternatively, the electrode of the electrode assembly is a negative electrode, and the battery cell further includes a plurality of positive electrodes. The electrode assembly and the positive electrodes are stacked, and along the stacking direction, the positive electrodes and the electrode assembly are alternately arranged.
[0023] According to some embodiments of the present invention, if the electrode of the electrode assembly is a positive electrode, in the projection of the positive electrode on the negative electrode along the stacking direction, the projection area of the positive electrode falls within the projection area of the negative electrode, and the projection area of the communication hole is located outside the projection area of the negative electrode.
[0024] According to some embodiments of the present invention, the distance from the axis of the communication hole to the edge of the positive electrode is 0.4 mm to 0.5 mm.
[0025] The battery according to the third aspect embodiment of the present invention includes a housing and the battery cell described in any one of the above embodiments, and the battery cell is disposed in the housing.
[0026] Some additional aspects and advantages of the present invention will be given in the following description, some will become apparent from the following description, or will be understood through the practice of the present invention. Description of the Drawings
[0027] The present invention will be further described below in conjunction with the drawings and embodiments, where:
[0028] Figure 1 is a schematic cross-sectional view of the electrode assembly according to an embodiment of the present invention;
[0029] Figure 2 is Figure 1 an enlarged schematic view of area A in
[0030] Figure 3 is Figure 1 a schematic cross-sectional view taken along line B-B in
[0031] Figure 4 is Figure 1 a schematic cross-sectional view of another embodiment taken along line B-B in
[0032] Figure 5 is a schematic structural view of the battery cell according to an embodiment of the present invention.
[0033] Reference Numerals:
[0034] Electrode 100; Positive electrode 101; Negative electrode 102;
[0035] First separator 200;
[0036] Second separator 300;
[0037] Hot pressing area 400; main body 410; recessed part 420; groove 421;
[0038] First gap 500;
[0039] Communication hole 600. Detailed implementation manner
[0040] The embodiments of the present utility model will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present utility model and should not be construed as a limitation to the present utility model.
[0041] In the description of the present utility model, it should be understood that the orientation descriptions such as up, down, front, back, left, right, etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present utility model.
[0042] In the description of the present utility model, the meaning of several is more than one, the meaning of multiple is more than two, greater than, less than, exceeding, etc. are understood as not including the present number, and above, below, within, etc. are understood as including the present number. If there is a description of first and second, it is only for the purpose of distinguishing technical features and should not be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.
[0043] In the description of the present utility model, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present utility model in combination with the specific content of the technical solution.
[0044] In the description of the present utility model, the descriptions referring to terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.
[0045] In the prior art, the thermal composite lamination process is often divided into open thermal composite and closed thermal composite. In the open thermal composite, the middle regions of the electrode sheet and the separator are hot-pressed to bond the electrode sheet and the separator, so that the four peripheral edges are in an open state. However, the open thermal composite will affect the formation test life of the battery. Therefore, the existing batteries mainly adopt the closed thermal composite.
[0046] In the closed thermal composite process, the edges of the separator are hot-pressed to confine the electrode sheet in a closed chamber, and there is no adhesion between the hot-pressed electrode sheet and the separator. However, since the edges of the separator are in a closed state, it is difficult for the electrolyte to infiltrate into the electrode sheet, and the fluidity of the electrolyte is poor. When the electrolyte infiltration effect is not good, the ion transport path becomes longer, which hinders the shuttling of lithium ions between the positive and negative electrodes. The electrode sheet that has not contacted the electrolyte cannot participate in the battery electrochemical reaction, and at the same time, the battery interface resistance increases, affecting the rate performance, discharge capacity, and service life of the lithium battery.
[0047] To solve the above problems, in this application, an electrode sheet assembly is proposed, as Figures 1 to 3 shown. The electrode sheet assembly includes an electrode sheet 100, a first separator 200, and a second separator 300. The electrode sheet 100 can be a positive electrode sheet or a negative electrode sheet. The first separator 200 and the second separator 300 are respectively located on both sides of the electrode sheet 100 along its thickness direction and are stacked with the electrode sheet 100. The edges of the first separator 200 and the second separator 300 are hot-pressed and connected to form a hot-pressed area 400. A receiving cavity for accommodating the electrode sheet 100 is formed between the first separator 200 and the second separator 300. Preferably, the distance from the electrode sheet 100 to the edge of the separator is 0.6 mm to 1 mm, and the width of the hot-pressed area is 0.2 mm to 0.4 mm.
[0048] It can be understood that, as Figure 2 shown, the electrode sheet 100 has a certain thickness. When the first separator 200 and the second separator 300 are coated on both sides thereof and hot-pressed and connected together, along the direction from the edge of the electrode sheet 100 to the hot-pressed area 400, the distance between the first separator 200 and the second separator 300 gradually decreases until they are hot-pressed together. There is still a gap between the hot-pressed area 400 and the edge of the electrode sheet 100, which is named the first gap 500 for convenience of description.
[0049] To facilitate the infiltration of the electrolyte into the electrode sheet 100, communication holes 600 are provided in the first separator 200 and the second separator 300 to communicate the receiving cavity with the external environment, so that the electrolyte can enter the receiving cavity through the communication holes 600 and react with the active substances on the electrode sheet 100. The communication holes 600 can be circular, square, triangular, etc., and can be formed by processing techniques such as drilling and laser drilling. In as Figure 2 and Figure 3In the illustrated embodiment, the communication holes 600 are formed by a laser drilling process, and first thermal lamination is performed and then drilling is carried out. Thus, during laser drilling, both the first diaphragm 200 and the second diaphragm 300 are penetrated by laser ablation, thereby simultaneously forming coaxial communication holes 600 in the first diaphragm 200 and the second diaphragm 300.
[0050] In some other embodiments, by controlling the drilling depth or changing the drilling process, the communication holes 600 can be formed only in the first diaphragm 200 or the second diaphragm 300, or drilling can be carried out on the first diaphragm 200 and the second diaphragm 300 respectively. In other embodiments, the process sequence of drilling can also be changed. For example, the first diaphragm 200 and the second diaphragm 300 are drilled respectively first, and then thermally laminated with the electrode tab 100, so as to realize the communication between the accommodating cavity and the external environment.
[0051] It should be noted that no matter whether the communication holes 600 are provided on the first diaphragm 200 and / or the second diaphragm 300, at least part of the area of the communication holes 600 should be ensured to communicate with the first gap 500, so that the electrolyte can be introduced. Specifically, in the projection on the plane where the electrode tab 100 is located along the thickness direction, at least part of the projection area of the communication holes 600 falls into the projection area of the first gap 500. That is, the projection area of the communication holes 600 can entirely fall into the projection area of the first gap 500, or alternatively, the projection area of the communication holes 600 can partially fall into the projection area of the first gap 500, and the remaining part falls into the projection area of the hot pressing area 400.
[0052] In the embodiments as Figure 2 and Figure 3 shown, a part of the projection area of the communication holes 600 falls into the projection area of the first gap 500, and the remaining part falls into the projection area of the hot pressing area 400. On the one hand, it can keep a sufficient distance between the communication holes 600 and the electrode tab 100 to avoid short - circuit phenomenon of the electrode tab 100 through the communication holes 600. On the other hand, part of the communication holes 600 are opened on the hot pressing area 400, which can reduce the influence of the opening on the diaphragm strength and avoid problems such as bending of the diaphragm due to insufficient strength.
[0053] Based on the above, in the present application, by providing the communication holes 600, the accommodation cavity where the electrode sheet 100 is located is communicated with the external environment. When the electrode sheet assembly enters the baking process, the moisture in the electrode sheet 100 can be better discharged, which is beneficial to improving the baking efficiency. In addition, in the liquid injection process, the electrolyte can enter the accommodation cavity through the communication holes 600, and the fluidity of the electrolyte is better, so that the wetting effect of the electrode sheet 100 is better, the formation activation degree is higher, and it is beneficial to improving the cycle life of the battery cell. Moreover, since the present application adopts the closed-mouth thermal lamination process, there is no special requirement for the type of separator, and the practicability is strong. After thermal lamination, the separator has no wrinkles. This structure of the present application can be compatible with special-shaped electrode sheets, such as circular electrode sheets, polygonal electrode sheets or L-shaped electrode sheets, etc.
[0054] In some embodiments, as Figure 3 shown, the hot pressing area 400 is a regular square ring structure, and the communication holes 600 are opened on the inner ring of the hot pressing area 400. In other embodiments, as Figure 4 shown, along the circumferential direction of the electrode sheet assembly, the hot pressing area 400 includes alternately arranged main body parts 410 and recessed parts 420, wherein the distance from the recessed part 420 to the electrode sheet 100 is less than the distance from the main body part 410 to the electrode sheet 100, and the communication holes 600 are arranged corresponding to the recessed parts 420, so that the distance from the communication holes 600 to the electrode sheet 100 is greater than the distance from the main body part 410 to the electrode sheet 100.
[0055] It should be noted that the "distance from the communication hole 600 to the electrode sheet 100" mentioned above should be understood as the minimum distance from the hole wall of the communication hole 600 to the electrode sheet 100. Specifically, any recessed part 420 and its two adjacent main body parts 410 define a groove 421, and the groove 421 is a part of the first gap 500. In some specific embodiments, along the thickness direction of the electrode sheet 100 and the projection on the plane where the electrode sheet 100 is located, the projection area of the communication hole 600 can entirely fall within the groove 421, or in other specific embodiments, the projection area of the communication hole 600 can partially fall within the groove 421 and the other part fall on the recessed part 420.
[0056] It should be understood that since the distance from the communication hole 600 to the electrode sheet 100 is farther, even after thermal lamination, the electrode sheet 100 still has a certain degree of freedom of movement in the accommodation cavity. Restricted by the abutting action of the two side main body parts 410, the electrode sheet 100 will not protrude from the communication hole 600, thus avoiding the risk of short circuit. In addition, since the communication hole 600 is communicated with the groove 421, the groove 421 can accommodate part of the electrolyte, so that the electrolyte can be stored in the groove 421 to ensure the wetting effect of the electrode sheet 100.
[0057] Further, the difference between the distance from the main body portion 410 to the electrode sheet 100 and the distance from the recessed portion 420 to the electrode sheet 100 is set as the recess depth D, and the recess depth D is also the groove depth of the groove 421. To ensure the connection strength of the hot pressing area 400, there are certain requirements for the recess depth D of the recessed portion 420. The distance from the edge of the hot pressing area 400 to the electrode sheet 100 is set as the hot pressing distance L, and the following relationship exists between the recess depth D and the hot pressing distance L: 2D ≤ L. When the recess depth D is within this range, both the connection strength of the hot pressing and the wetting effect of the electrode sheet 100 can be better ensured.
[0058] Preferably, the length ratio of the main body portion 410 to the recessed portion 420 is within the range of 2 to 4, and the length of the recessed portion 420 is within the range of 1 mm to 4 mm.
[0059] In some embodiments, as Figure 3 and Figure 4 shown, along the circumferential direction of the electrode sheet assembly, the hot pressing area 400 is continuous. In other embodiments, along the circumferential direction of the electrode sheet assembly, the hot pressing area 400 is discontinuous. It can be understood that if the hot pressing area 400 is discontinuous, a flow-through area is defined between adjacent hot pressing areas 400, and the first separator 200 and the second separator 300 at the flow-through area are not connected, so that the electrolyte can enter the accommodation cavity from the flow-through area, further increasing the flow-through area between the accommodation cavity and the external environment, thereby improving the moisture loss efficiency in the baking process and the electrolyte wetting efficiency in the formation process.
[0060] Further, to ensure the strength of the hot pressing connection and avoid an increase in the internal resistance of the battery due to excessive electrolyte in the electrode sheet 100, the length ratio of the hot pressing area 400 to the flow-through area needs to be controlled within the range of 10 to 15. It can be understood that the "length of the hot pressing area 400 and the flow-through area" refers to the length along the circumferential direction of the electrode sheet assembly, that is, the length after the hot pressing area 400 and the flow-through area are unfolded along the circumferential direction of the electrode sheet assembly.
[0061] In some embodiments, as Figure 3 and Figure 4 shown, the communication holes 600 are circular holes, which are made by laser drilling process. The aperture of the circular holes is 0.22 mm to 0.5 mm. The circular holes within this scale range can be more easily obtained by the laser drilling process, avoiding an increase in processing difficulty due to the circular hole size being too large or too small. On the same first separator 200 or the same second separator 300, the interval between two adjacent circular holes is 5 to 10 times the aperture. For example, if the aperture of the circular hole is 0.5 mm, the axial distance between two adjacent circular holes should be within the range of 2.5 mm to 5 mm, and the processing efficiency within this range is relatively high.
[0062] In the second aspect of the embodiments of the present application, a battery cell is proposed, as Figure 5As shown, the battery cell has the electrode assembly mentioned in any of the above embodiments. Based on the foregoing, the electrode 100 in the electrode assembly can be the positive electrode 101 or the negative electrode 102. As Figure 5 shown, if the electrode 100 of the electrode assembly is the positive electrode 101, the battery cell further includes a plurality of negative electrodes 102. Each electrode assembly and the negative electrode 102 are stacked, and along the stacking direction, the negative electrode 102 and the electrode assembly are alternately arranged. It can be understood that since the electrode assembly includes the first separator 200, the positive electrode 101, and the second separator 300, after being stacked with the negative electrode 102, the two sides of the negative electrode 102 are respectively in contact with the first separator 200 and the second separator 300. The first separator 200 and the second separator 300 play a role in isolating the positive electrode 101 and the negative electrode 102, avoiding short circuit caused by their direct contact.
[0063] Similarly, in some other embodiments, the electrode 100 of the electrode assembly can also be the negative electrode 102. Correspondingly, the battery cell further includes a plurality of positive electrodes 101. The electrode assembly and the positive electrode 101 are stacked, and along the stacking direction, the positive electrode 101 and the electrode assembly are alternately arranged.
[0064] Furthermore, it should be understood that in order to reduce the phenomenon of lithium plating during the use of the battery, the size of the negative electrode 102 is often larger than that of the positive electrode 101 to accommodate more active materials, so as to have more space to store and release lithium ions. That is, in the projection along the stacking direction, the projection area of the positive electrode 101 falls within the projection area of the negative electrode 102. It can be understood that when the electrode 100 of the electrode assembly is the positive electrode 101, since the size of the positive electrode 101 itself is small, the size difference between the formed electrode assembly and the negative electrode 102 is small, thus improving the energy density of the battery.
[0065] The size of the electrode assembly is larger than that of the negative electrode 102. In the projection along the stacking direction on the negative electrode 102, the projection area of the communication hole 600 should be located outside the projection area of the negative electrode 102 to avoid the risk of short circuit caused by the exposure of the negative electrode 102 through the communication hole 600 in the accommodation cavity. Further, the distance from the axis of the communication hole 600 to the edge of the positive electrode 101 is 0.4 mm to 0.5 mm. If it is less than this range, the probability of short circuit between the positive electrode 101 and the negative electrode 102 through the communication hole 600 will increase greatly. If it is greater than this range, the distance from the electrolyte to the electrode 100 through the communication hole 600 is long, and the flow efficiency is reduced.
[0066] In the embodiment where the electrode 100 of the electrode assembly is the negative electrode 102, since the size of the negative electrode 102 is larger than that of the positive electrode 101, the projection area of the communication hole 600 will inevitably be outside the projection area of the positive electrode 101, and the safety is better.
[0067] A third aspect embodiment of the present application further provides a battery, which includes a housing and the battery cell described in any one of the above embodiments, and the battery cell is disposed in the housing. Due to the good infiltration effect, this kind of battery has a lower impedance and a longer battery life. This battery can be a 3C battery, used in various electronic devices such as mobile phones and computers, or it can be a power battery, used in devices such as new energy vehicles.
[0068] The above has described the embodiments of the present utility model in detail with reference to the accompanying drawings. However, the present utility model is not limited to the above embodiments. Within the scope of knowledge possessed by those of ordinary skill in the art to which it pertains, various changes can be made without departing from the gist of the present utility model. In addition, without conflict, the embodiments of the present utility model and the features in the embodiments can be combined with each other.
Claims
1. The pole piece assembly, characterized in that, Comprising: A pole piece; A first separator located on one side of the pole piece in the thickness direction; A second separator located on the other side of the pole piece in the thickness direction. The second separator is connected to the edge of the first separator and defines a hot pressing area. An accommodating cavity for accommodating the pole piece is formed between the first separator and the second separator; Wherein, there is a first gap between the edge of the pole piece and the hot pressing area. At least one of the first separator and the second separator is provided with a communication hole. Along the projection on the plane where the pole piece is located in the thickness direction, at least part of the projection area of the communication hole falls within the projection area of the first gap.
2. The pole piece assembly according to claim 1, characterized in that, Along the projection on the pole piece in the thickness direction, a part of the projection area of the communication hole is located within the projection area of the first gap, and the remaining part is located within the projection area of the hot pressing area.
3. The electrode sheet assembly according to claim 1, characterized in that, Along the circumferential direction of the pole piece assembly, the hot pressing area includes alternately arranged main body parts and recessed parts. The distance from the recessed part to the pole piece is less than the distance from the main body part to the pole piece. The communication hole is arranged corresponding to the recessed part, so that the distance from the communication hole to the pole piece is greater than the distance from the main body part to the pole piece.
4. The electrode sheet assembly according to claim 3, characterized in that, Set the difference between the distance from the main body part to the pole piece and the distance from the recessed part to the pole piece as the recess depth D, and the distance from the edge of the hot pressing area to the pole piece as the hot pressing distance L. The recess depth D and the hot pressing distance L have the following relationship: 2D ≤ L.
5. The electrode sheet assembly according to claim 1, wherein Along the circumferential direction of the pole piece assembly, the hot pressing area is continuous; Or, along the circumferential direction of the pole piece assembly, the hot pressing area is not connected. Set a circulation area defined between adjacent hot pressing areas. The ratio of the length of the hot pressing area to the length of the circulation area is within the range of 10 to 15.
6. The pole piece assembly according to any one of claims 1 to 5, characterized in that The communication hole is a round hole, and the aperture of the round hole is from 0.22 mm to 0.5 mm. On the same first separator or the same second separator, the interval between two adjacent round holes is five to ten times the aperture.
7. The battery cell is characterized in that, Comprising: A plurality of pole piece assemblies according to any one of claims 1 to 6; Wherein, the pole piece of the pole piece assembly is a positive pole piece, and the battery cell further includes a plurality of negative pole pieces. The pole piece assembly and the negative pole pieces are stacked, and, along the stacking direction, the negative pole pieces and the pole piece assembly are alternately arranged; Or, the pole piece of the pole piece assembly is a negative pole piece, and the battery cell further includes a plurality of positive pole pieces. The pole piece assembly and the positive pole pieces are stacked, and, along the stacking direction, the positive pole pieces and the pole piece assembly are alternately arranged.
8. The battery cell according to claim 7, characterized in that, If the pole piece of the pole piece assembly is a positive pole piece, along the projection on the negative pole piece in the stacking direction, the projection area of the positive pole piece falls within the projection area of the negative pole piece, and the projection area of the communication hole is located outside the projection area of the negative pole piece.
9. The battery cell according to claim 8, characterized in that, The distance from the axis of the communication hole to the edge of the positive pole piece is from 0.4 mm to 0.5 mm.
10. A battery, characterized in that, Comprising a housing and a battery cell according to any one of claims 7 to 9, and the battery cell is arranged in the housing.