Pole piece structure and core package assembly

Abstract

The invention discloses a pole piece structure and a core package assembly, the pole piece structure comprises a foil and a coating layer, the foil comprises a first part and second parts, and the second parts are arranged at two ends of the first part along the width direction of the foil. The coating layers are arranged on the two sides of the first part in the thickness direction of the foil, through grooves are formed in the coating layers in the width direction of the foil, the through grooves penetrate through the coating layers, and the diaphragm covers the through grooves. The pole piece structure and the core package assembly solve the technical problems that black spots and lithium precipitation are easily caused by gas accumulation during formation of a core package of a laminated battery.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a pole piece structure and a core package assembly. Background Art

[0002] In the production process of lithium-ion batteries, the core package hot pressing process and the formation process are two important steps. First, the battery undergoes a hot pressing process, which heats and pressurizes the diaphragm and the pole piece to make them fit more closely, in order to increase the energy density of the battery. However, because the core package of the laminated battery causes the diaphragm and the pole piece to fit too closely during the hot pressing process, after the core package enters the formation process, the coating on the electrode piece reacts with the electrolyte to produce gas, which easily gathers at the edge of the pole piece and is difficult to discharge. If these gases cannot be removed in time, they will cause problems such as black spots and lithium precipitation, and may even endanger the safety of the core package. Summary of the invention

[0003] One object of the present invention is to provide a pole piece structure and a core package assembly, which is intended to solve the technical problem that black spots and lithium precipitation are easily generated due to gas accumulation during the formation of laminated batteries.

[0004] To achieve the above object, the present invention provides a solution: a pole piece structure and a core package assembly, characterized in that it comprises: a foil, the foil comprises a first part and a second part, the second part is arranged at both ends of the first part along the width direction of the foil;

[0005] The coating layer is arranged on both sides of the first part along the thickness direction of the foil, and a through groove is opened in the coating layer along the width direction of the foil, and the through groove runs through the coating layer.

[0006] Optionally, the coating layer is divided into a third part and a fourth part, the fourth part is arranged on both sides of the third part along the width direction of the foil, the through groove includes a first groove and a second groove, the first groove is opened in the third part along the width direction of the foil, the width of the first groove is L1, the second groove is opened in the fourth part along the width direction of the foil, the width of the second groove is L2, and L2<L1.

[0007] Optionally, the thickness of the single-sided coating layer is L3, the depth of the first groove is L4, the depth of the second groove is L5, and 0.08≤L5 / L3≤L4 / L3≤0.12.

[0008] Optionally, the width of the foil is L6, and in the width direction of the foil, the length of the third portion is L7, and 0.3≤L7 / L6≤0.7.

[0009] Optionally, 0.2≤L2 / L1≤0.5.

[0010] Optionally, along the length direction of the foil, the cross-sectional shape of the first groove and / or the second groove is fan-shaped.

[0011] Optionally, a plurality of first grooves are provided along the length direction of the foil, a plurality of second grooves are provided along the length direction of the foil, and each first groove is connected to at least two of the plurality of second grooves.

[0012] Optionally, the third part includes a first supporting part, a plurality of first grooves are arranged at intervals, and the first supporting part is arranged between adjacent first grooves;

[0013] Alternatively, the fourth portion includes a second supporting portion, a plurality of second grooves are arranged at intervals, and the second supporting portion is arranged between adjacent second grooves.

[0014] Optionally, the third part includes a first supporting part, a plurality of first grooves are arranged at intervals, and the first supporting part is arranged between adjacent first grooves;

[0015] The fourth part includes a second supporting part, a plurality of second grooves are arranged at intervals, and the second supporting part is arranged between adjacent second grooves.

[0016] Optionally, the width of the first supporting portion gradually increases along a direction approaching the center of the foil.

[0017] Optionally, the width of the second supporting portion gradually increases along a direction approaching the center of the foil.

[0018] To achieve the above-mentioned purpose, the present invention provides a solution: a core package assembly, including a plurality of pole piece structures and a diaphragm, wherein the diaphragm is arranged on two opposite sides of the pole piece structure and covered with a through groove.

[0019] The beneficial effects of the present invention are:

[0020] The pole piece structure includes a foil and a coating layer, the foil includes a first part and a second part, the second part is arranged at both ends of the first part along the width direction of the foil. The coating layer is arranged on both sides of the first part along the thickness direction of the foil, the coating layer is provided with a through groove along the width direction of the foil, the through groove penetrates the coating layer, and the diaphragm cover is provided with a through groove.

[0021] In actual applications, during the core package component formation process, the coating layer will release a large amount of gas, which will be quickly discharged from the core package component through the through groove. This design effectively avoids the accumulation of gas at the edge of the pole piece and reduces the black spots and lithium precipitation caused by gas retention. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0023] Figure 1is a structural schematic diagram for showing a core package assembly provided by an embodiment of the present invention;

[0024] Figure 2 is a structural schematic diagram for showing the specific structure of a core package assembly provided by an embodiment of the present invention;

[0025] Figure 3 It is a cross-sectional structural schematic diagram provided by the present invention for showing the specific structure of the core package assembly;

[0026] Figure 4 is a structural schematic diagram for showing a pole piece structure provided by an embodiment of the present invention;

[0027] Figure 5 is a partial structural schematic diagram of the depth of the first groove and the depth of the second groove provided by an embodiment of the present invention;

[0028] Figure 6 It is a structural schematic diagram for showing the positional relationship between the coating layer and the foil provided by an embodiment of the present invention;

[0029] Figure 7 The embodiment of the present invention provides Figure 2 Schematic diagram of the cross-sectional structure at AA in the middle;

[0030] Figure 8 is a schematic structural diagram for showing a first supporting part and a second supporting part provided by an embodiment of the present invention;

[0031] Fig. 9 The embodiment of the present invention provides Figure 5 Schematic diagram of the cross-sectional structure at BB in the middle.

[0032] Description of Figure Numbers:

[0033] 20. Foil; 21. First part; 22. Second part; 30. Coating layer; 31. Through groove; 32. Third part; 321. First groove; 322. First supporting part; 33. Fourth part; 331. Second groove; 332. Second supporting part; 40. Diaphragm; 41. Width direction. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] See also Figure 1 , Figure 2 , Figure 3 and Figure 4 , Figure 1 is a schematic diagram of the structure of a core package assembly provided by an embodiment of the present invention, Figure 2 is a structural schematic diagram for showing the specific structure of a core package assembly provided by an embodiment of the present invention, Figure 3 is a cross-sectional structural schematic diagram provided by the present invention for showing the specific structure of the core package assembly, Figure 4 It is a structural schematic diagram for showing the pole piece structure provided by an embodiment of the present invention.

[0036] The embodiment of the present invention provides a core package assembly, including a pole piece structure and a diaphragm 40, wherein the diaphragm 40 is disposed on two opposite sides of the pole piece structure.

[0037] Specifically, the pole piece structure includes: a foil 20 and a coating layer 30, wherein the foil 20 includes a first portion 21 and a second portion 22, wherein the second portion 22 is disposed at both ends of the first portion 21 along a width direction 41 of the foil 20. The coating layer 30 is disposed at both sides of the first portion 21 along a thickness direction of the foil 20, and the coating layer 30 is provided with a through groove 31 along a width direction 41 of the foil 20, wherein the through groove 31 penetrates the coating layer 30, and the diaphragm 40 is provided with the through groove 31.

[0038] Note that Figure 4 In order to facilitate the display, only part of the pole piece structure is intercepted. The pole piece structure is a rectangle, and the extension direction of the short side of the rectangle is the width direction 41 of the foil 20.

[0039] In actual application, during the core package component formation process, the coating layer 30 releases a large amount of gas, which is quickly discharged from the core package component through the through groove 31. This design effectively avoids the accumulation of gas at the edge of the pole piece, reduces the black spots and lithium precipitation caused by gas retention, and significantly improves the processing quality of the core package component.

[0040] In one embodiment, see Figure 4 The coating layer 30 is divided into a third portion 32 and a fourth portion 33. The fourth portion 33 is arranged on both sides of the third portion 32 along the width direction 41 of the foil 20. The through groove 31 includes a first groove 321 and a second groove 331. The first groove 321 is opened in the third portion 32 along the width direction 41 of the foil 20, and the width of the first groove 321 is L1. The second groove 331 is opened in the fourth portion 33 along the width direction 41 of the foil 20, and the width of the second groove 331 is L2, and L2<L1.

[0041] In actual applications, the first groove 321 is located in the central area of ​​the core package assembly, where more gas is generated, so a wider groove is required to accommodate and discharge a large amount of gas in time. The width of the second groove 331 is narrower because when the gas enters the narrow groove from the wide groove, the air flow speed is accelerated, which further promotes the discharge of the gas, thereby improving the exhaust efficiency. Through this design, the gas discharge path is optimized, and the gas can be quickly discharged from the pole piece, avoiding the accumulation of gas at the edge. This effectively reduces the black spots and lithium precipitation caused by gas retention, ensures the quality of the pole piece, and improves the overall performance of the battery.

[0042] In this embodiment, 0.2≤L2 / L1≤0.5.

[0043] Optionally, see Figure 5 The thickness of the single-side coating layer 30 is L3, the depth of the first groove 321 is L4, the depth of the second groove 331 is L5, and 0.08≤L5 / L3≤L4 / L3≤0.12.

[0044] In practical applications, the thickness of the coating layer 30 matches the depth of the groove, ensuring that the gas can be discharged smoothly and quickly from the coating layer 30 and effectively reducing the risk of gas retention. At the same time, this design can avoid the problem of poor gas discharge caused by too shallow a groove or excessive weakening of the coating layer 30 caused by too deep a groove, thereby optimizing the structural stability of the pole piece structure and improving the performance and safety of the battery.

[0045] Optionally, see Figure 4 The width of the foil 20 is L6, and in the width direction 41 of the foil 20, the length of the third portion 32 is L7, and 0.3≤L7 / L6≤0.7.

[0046] In practical applications, the longer third portion 32 provides a larger discharge space for the gas, ensuring that the gas can be discharged smoothly through the first groove 321 and the second groove 331, thereby preventing the gas from being retained inside the pole piece.

[0047] Further, refer to Figure 6 and Figure 7 Along the length direction of the foil 20 , the cross-sectional shape of the first groove 321 and / or the second groove 331 is fan-shaped.

[0048] In practical applications, the fan-shaped cross-section design effectively reduces stress concentration. Compared with straight lines or other sharp-angled notches, the fan-shaped cross-section allows the airflow to transition more smoothly and avoids local high stress at the slot wall. This helps to reduce the structural damage that may occur to the pole piece during production or use, especially when the gas is discharged quickly, reducing the risk of material rupture or deformation due to stress concentration. Therefore, this design not only optimizes gas emissions, but also improves the mechanical stability and overall reliability of the pole piece, thereby enhancing the long-term performance and safety of the battery.

[0049] Optionally, refer to Figure 7 A plurality of first grooves 321 are provided along the length direction of the foil 20 , a plurality of second grooves 331 are provided along the length direction of the foil 20 , and each first groove 321 is connected to at least two of the plurality of second grooves 331 .

[0050] In practical applications, one first groove 321 is connected to multiple second grooves 331, which can effectively improve the efficiency of gas exhaust. Multiple second grooves 331 provide more exhaust channels for gas, so that the gas can quickly diffuse and exhaust from the first groove 321, reduce the retention and accumulation of gas during the exhaust process, and ensure that the gas released by the coating layer 30 during the core package component formation process can be quickly discharged, thereby reducing the black spots and lithium precipitation caused by gas retention.

[0051] Further, refer to Figure 8 and Fig. 9 The third portion 32 includes a first support portion 322 , a plurality of first grooves 321 are arranged at intervals, and the first support portion 322 is arranged between adjacent first grooves 321 , or the fourth portion 33 includes a second support portion 332 , a plurality of second grooves 331 are arranged at intervals, and the second support portion 332 is arranged between adjacent second grooves 331 .

[0052] Optionally, the third portion 32 includes a first support portion 322 , a plurality of first grooves 321 are arranged at intervals, and the first support portion 322 is arranged between adjacent first grooves 321 ; the fourth portion 33 includes a second support portion 332 , a plurality of second grooves 331 are arranged at intervals, and the second support portion 332 is arranged between adjacent second grooves 331 .

[0053] In practical applications, by providing a support portion between the adjacent first groove 321 and second groove 331, the stability of the pole piece structure can be effectively enhanced. The first support portion 322 and the second support portion 332 play a supporting role, preventing the first groove 321 and the second groove 331 from deforming or collapsing during the hot pressing process, thereby ensuring that the coating layer 30 can maintain a uniform exhaust effect and a smooth gas exhaust path during the core package component formation process. In addition, the support portion can also optimize the mechanical properties of the coating layer 30, enhance its compressive resistance and deformation resistance, and improve the safety and reliability of the battery.

[0054] Further, refer to Fig. 9 The width of the first supporting portion 322 gradually increases along a direction approaching the center of the foil 20 .

[0055] Optionally, the width of the second supporting portion 332 gradually increases along a direction approaching the center of the foil 20 .

[0056] In actual applications, the width of the first support portion 322 and the second support portion 332 gradually increases along the center of the foil 20, which can effectively distribute and evenly withstand the pressure from the diaphragm 40 during hot pressing and the pressure of the gas during formation, thereby increasing the strength and stability of the support portion, further improving the structural stability of the coating layer 30, and reducing deformation or damage of the first groove 321 and the second groove 331 caused by excessive pressure during hot pressing.

[0057] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0058] It should also be noted that when an element is referred to as being "fixed on" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element at the same time. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or may be indirectly connected to the other element through an intermediate element.

[0059] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0060] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A pole piece structure, characterized in that: include: A foil, the foil comprising a first portion and a second portion, the second portion being arranged at two ends of the first portion along a width direction of the foil; A coating layer is provided on both sides of the first portion along the thickness direction of the foil, and a through groove is provided on the coating layer along the width direction of the foil, and the through groove passes through the coating layer.

2. The pole piece structure according to claim 1, characterized in that: The coating layer is divided into a third part and a fourth part, the fourth part is arranged on both sides of the third part along the width direction of the foil, the through groove includes a first groove and a second groove, the first groove is opened in the third part along the width direction of the foil, the width of the first groove is L1, the second groove is opened in the fourth part along the width direction of the foil, the width of the second groove is L2, and L2<L1.

3. The pole piece structure according to claim 2, characterized in that: The thickness of the coating layer on one side is L3, the depth of the first groove is L4, the depth of the second groove is L5, and 0.08≤L5 / L3≤L4 / L3≤0.

12.

4. The pole piece structure according to claim 2, characterized in that: The width of the foil is L6, and in the width direction of the foil, the length of the third portion is L7, 0.3≤L7 / L6≤0.

7.

5. The pole piece structure according to claim 2, characterized in that: 0.2≤L2 / L1≤0.

5.

6. The pole piece structure according to any one of claims 2 to 5, characterized in that: Along the length direction of the foil, the cross-sectional shape of the first groove and / or the second groove is fan-shaped.

7. The pole piece structure according to any one of claims 2 to 5, characterized in that: A plurality of the first grooves are provided along the length direction of the foil, a plurality of the second grooves are provided along the length direction of the foil, and each of the first grooves is connected to at least two of the plurality of the second grooves.

8. The pole piece structure according to claim 7, characterized in that: The third part includes a first supporting part, a plurality of the first grooves are arranged at intervals, and the first supporting part is arranged between adjacent first grooves; Alternatively, the fourth portion includes a second supporting portion, a plurality of the second grooves are arranged at intervals, and the second supporting portion is arranged between adjacent second grooves.

9. The pole piece structure according to claim 7, characterized in that: The third part includes a first supporting part, a plurality of the first grooves are arranged at intervals, and the first supporting part is arranged between adjacent first grooves; The fourth portion includes a second supporting portion, a plurality of the second grooves are arranged at intervals, and the second supporting portion is arranged between adjacent second grooves.

10. The pole piece structure according to any one of claims 8 or 9, characterized in that: The width of the first supporting portion gradually increases along a direction approaching the center of the foil.

11. The pole piece structure according to any one of claims 8 or 9, characterized in that: The width of the second supporting portion gradually increases along a direction approaching the center of the foil.

12. A core package assembly, characterized in that: The core package assembly comprises a plurality of pole piece structures and diaphragms according to any one of claims 1 to 11, wherein the diaphragms are arranged on opposite sides of the pole piece structure and cover the through groove.

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