Pole piece structure and core package assembly

Abstract

The application 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 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 through the coating layer. The diaphragm cover is provided with the through groove. The pole piece structure and the core package assembly solve the technical problem that the core package of the laminated battery is prone to black spots and lithium precipitation due to gas accumulation during formation.

Description

An electrode structure and a core package assembly Technical Field

[0001] This invention relates to the field of battery technology, and in particular to an electrode structure and a core pack assembly. Background Technology

[0002] In the production process of lithium-ion batteries, the hot-pressing and formation processes are two crucial steps. First, the battery undergoes a hot-pressing process, where heating and pressurization are applied to ensure a tighter bond between the separator and electrodes, aiming to improve the battery's energy density. However, because the hot-pressing process in stacked batteries results in an overly tight bond between the separator and electrodes, when the battery enters the formation process, the coating on the electrodes reacts with the electrolyte to generate gas. This gas tends to accumulate at the edges of the electrodes and is difficult to expel. If this gas cannot be removed in time, it can cause problems such as black spots and lithium plating, and may even jeopardize the safety of the battery pack. Summary of the Invention

[0003] One object of the present invention is to provide an electrode structure and a core-pack assembly, which aims to solve the technical problem that black spots and lithium plating are easily caused by gas accumulation during the formation of stacked batteries.

[0004] To achieve the above objectives, the present invention provides a solution: an electrode structure and a core-pack assembly, characterized in that it includes: a foil, the foil comprising a first part and a second part, the second part being disposed at both ends of the first part along the width direction of the foil;

[0005] The coating layer is disposed on both sides of the first part along the thickness direction of the foil, and the coating layer has through grooves along the width direction of the foil, the through grooves penetrating the coating layer.

[0006] Optionally, the coating layer is divided into a third part and a fourth part. The fourth part is disposed 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 and the width of the first groove is L1. The second groove is opened in the fourth part along the width direction of the foil and the width of the second groove is L2, where L2 < L1.

[0007] Optionally, 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.

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

[0009] Optionally, 0.2 ≤ L2 / L1 ≤ 0.5.

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

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

[0012] Optionally, the third part includes a first support part, and a plurality of first slots are spaced apart, with the first support part disposed between adjacent first slots;

[0013] Alternatively, the fourth part includes a second support part, and a plurality of second slots are spaced apart, with the second support part disposed between adjacent second slots.

[0014] Optionally, the third part includes a first support part, and a plurality of first slots are spaced apart, with the first support part disposed between adjacent first slots;

[0015] The fourth part includes a second support part, and multiple second slots are spaced apart, with the second support part disposed between adjacent second slots.

[0016] Optionally, the width of the first support gradually increases along the direction closer to the center of the foil.

[0017] Optionally, the width of the second support gradually increases along the direction closer to the center of the foil.

[0018] To achieve the above objectives, the present invention provides a solution: a core package assembly comprising multiple electrode structures and a diaphragm, wherein the diaphragm is disposed on opposite sides of the electrode structures and is covered with a through groove.

[0019] The beneficial effects of this invention are as follows:

[0020] The electrode structure includes a foil and a coating layer. The foil includes a first part and a second part, with the second part disposed at both ends of the first part along the width direction of the foil. The coating layer is disposed on both sides of the first part along the thickness direction of the foil, and a through groove is formed in the coating layer along the width direction of the foil, the through groove penetrating the coating layer, and a diaphragm covers the through groove.

[0021] In practical applications, during the core-pack module formation process, the coating layer releases a large amount of gas, which is rapidly discharged from the core-pack module through channels. This design effectively avoids gas accumulation at the electrode edges, reducing black spots and lithium plating caused by gas retention. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

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

[0024] Figure 2 is a structural schematic diagram provided in an embodiment of the present invention to illustrate the specific structure of the core package assembly;

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

[0026] Figure 4 is a schematic diagram of the electrode structure provided in 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 in an embodiment of the present invention;

[0028] Figure 6 is a schematic diagram of the structure provided in an embodiment of the present invention for demonstrating the positional relationship between the coating layer and the foil;

[0029] Figure 7 is a schematic diagram of the cross-sectional structure at point AA in Figure 2 provided in an embodiment of the present invention;

[0030] Figure 8 is a structural schematic diagram of the first support portion and the second support portion provided in an embodiment of the present invention;

[0031] Figure 9 is a schematic diagram of the cross-sectional structure at BB in Figure 5 provided by an embodiment of the present invention.

[0032] Explanation of icon numbers:

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

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0035] Please refer to Figures 1, 2, 3 and 4. Figure 1 is a structural schematic diagram of the core package assembly provided in an embodiment of the present invention. Figure 2 is a structural schematic diagram of the specific structure of the core package assembly provided in an embodiment of the present invention. Figure 3 is a cross-sectional structural schematic diagram of the specific structure of the core package assembly provided in the present invention. Figure 4 is a structural schematic diagram of the electrode structure provided in an embodiment of the present invention.

[0036] An embodiment of the present invention provides a core package assembly, including an electrode structure and a diaphragm 40, wherein the diaphragm 40 is disposed on opposite sides of the electrode structure.

[0037] Specifically, the electrode structure includes a foil 20 and a coating layer 30. The foil 20 includes a first part 21 and a second part 22. The second part 22 is disposed at both ends of the first part 21 along the width direction 41 of the foil 20. The coating layer 30 is disposed on both sides of the first part 21 along the thickness direction of the foil 20. The coating layer 30 has a through groove 31 along the width direction 41 of the foil 20, and the through groove 31 penetrates the coating layer 30. The diaphragm 40 covers the through groove 31.

[0038] Note that in Figure 4, only a portion of the electrode structure is shown for ease of illustration. The electrode structure is rectangular, and the direction of the extension of the short side of the rectangle is the width direction 41 of the foil 20.

[0039] In practical applications, during the core-pack module formation process, the coating layer 30 releases a large amount of gas, which is rapidly discharged from the core-pack module through the channel 31. This design effectively avoids gas accumulation at the electrode edges, reduces black spots and lithium plating caused by gas retention, and significantly improves the processing quality of the core-pack module.

[0040] In one embodiment, referring to FIG4, the coating layer 30 is divided into a third part 32 and a fourth part 33. The fourth part 33 is disposed on both sides of the third part 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 part 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 part 33 along the width direction 41 of the foil 20, and the width of the second groove 331 is L2, where L2 < L1.

[0041] In practical applications, the first slot 321 is located in the central region of the cell assembly, where a large amount of gas is generated. Therefore, a wider slot is needed to accommodate and promptly expel this large amount of gas. The second slot 331 is narrower because the airflow velocity increases as gas moves from the wider slot to the narrower slot, further promoting gas expulsion and improving exhaust efficiency. This design optimizes the gas emission path, allowing gas to quickly exit the electrode and preventing gas accumulation at the edges. This effectively reduces black spots and lithium plating caused by gas retention, ensuring electrode quality and improving the overall battery performance.

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

[0043] Optionally, referring to Figure 5, the thickness of the single-sided 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 is matched with the depth of the groove, ensuring that gas can be smoothly and quickly discharged from the coating layer 30 and effectively reducing the risk of gas retention. At the same time, this design can avoid the problems of poor gas discharge caused by an excessively shallow groove or excessive weakening of the coating layer 30 caused by an excessively deep groove, thereby optimizing the structural stability of the electrode structure and improving the performance and safety of the battery.

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

[0046] In practical applications, the longer third section 32 provides a larger exhaust space for the gas, ensuring that the gas can be smoothly discharged through the first groove 321 and the second groove 331, avoiding the gas from being trapped inside the electrode.

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

[0048] In practical applications, the fan-shaped cross-section design effectively reduces stress concentration. Compared to straight lines or other sharp-angled notches, the fan-shaped cross-section allows for a smoother airflow transition, avoiding localized high stress at the notch walls. This helps reduce potential structural damage to the electrode during production or use, especially during rapid gas emission, reducing the risk of material cracking or deformation due to stress concentration. Therefore, this design not only optimizes gas emission but also improves the mechanical stability and overall reliability of the electrode, thereby enhancing the long-term performance and safety of the battery.

[0049] Optionally, referring to FIG7, a plurality of first grooves 321 are provided along the length direction of foil 20, and a plurality of second grooves 331 are provided along the length direction of foil 20, wherein at least two of each first groove 321 and the plurality of second grooves 331 are connected.

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

[0051] Further, referring to Figures 8 and 9, the third part 32 includes a first support part 322, and a plurality of first grooves 321 are spaced apart, with the first support part 322 disposed between adjacent first grooves 321; or, the fourth part 33 includes a second support part 332, and a plurality of second grooves 331 are spaced apart, with the second support part 332 disposed between adjacent second grooves 331.

[0052] Optionally, the third part 32 includes a first support part 322, and a plurality of first grooves 321 are spaced apart. The first support part 322 is disposed between adjacent first grooves 321. The fourth part 33 includes a second support part 332, and a plurality of second grooves 331 are spaced apart. The second support part 332 is disposed between adjacent second grooves 331.

[0053] In practical applications, by providing support portions between adjacent first grooves 321 and second grooves 331, the stability of the electrode structure can be effectively enhanced. The first support portion 322 and the second support portion 332 provide support, preventing deformation or collapse of the first groove 321 and second groove 331 during hot pressing, thereby ensuring that the coating layer 30 maintains a uniform venting effect and unobstructed gas emission path during the core-packaging assembly formation process. Furthermore, the support portions can optimize the mechanical properties of the coating layer 30, enhancing its compressive strength and deformation resistance, and improving the safety and reliability of the battery.

[0054] Furthermore, referring to Figure 9, the width of the first support portion 322 gradually increases along the direction close to the center of the foil 20.

[0055] Optionally, the width of the second support portion 332 gradually increases along the direction close to the center of the foil 20.

[0056] In practical applications, the widths of the first support portion 322 and the second support portion 332 gradually increase along the center of the foil 20, which can effectively distribute and evenly bear 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 the 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 (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component 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 a component is referred to as being "fixed to" or "set on" another component, it can be directly on the other component or may be connected to an intermediary component. When a component is referred to as being "connected to" another component, it can be directly connected to the other component or indirectly connected to the other component through an intermediary component.

[0059] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0060] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. An electrode structure, characterized in that, include: A foil sheet, comprising a first part and a second part, wherein the second part is disposed at both ends of the first part along the width direction of the foil sheet; a coating layer, wherein the coating layer is disposed on both sides of the first part along the thickness direction of the foil sheet, wherein the coating layer has through grooves along the width direction of the foil sheet, the through grooves penetrating the coating layer; the through grooves include a first groove and a second groove, wherein a plurality of first grooves are disposed along the length direction of the foil sheet, and a plurality of second grooves are disposed along the length direction of the foil sheet, wherein each first groove and at least two of the plurality of second grooves are connected.

2. The electrode 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 disposed on both sides of the third part along the width direction of the foil. The first groove is opened in the third part along the width direction of the foil, and the second groove is opened in the fourth part along the width direction of the foil. The width of the first groove is L1, and the width of the second groove is L2, where L2 < L1.

3. The electrode 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 electrode structure according to claim 2, characterized in that, The foil has a width of L6, and the third part has a length of L7 in the width direction of the foil, where 0.3 ≤ L7 / L6 ≤ 0.

7.

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

5.

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

7. The electrode structure according to claim 2, characterized in that, The third part includes a first support part, and a plurality of first slots are spaced apart, with the first support parts disposed between adjacent first slots; or, the fourth part includes a second support part, and a plurality of second slots are spaced apart, with the second support parts disposed between adjacent second slots.

8. The electrode structure according to claim 2, characterized in that, The third part includes a first support part, and a plurality of first slots are spaced apart, with the first support parts disposed between adjacent first slots; the fourth part includes a second support part, and a plurality of second slots are spaced apart, with the second support parts disposed between adjacent second slots.

9. The electrode structure according to any one of claims 7 or 8, characterized in that, The width of the first support portion gradually increases along the direction close to the center of the foil.

10. The electrode structure according to any one of claims 7 or 8, characterized in that, The width of the second support gradually increases along the direction close to the center of the foil.

11. A core-packaging assembly, characterized in that, The core assembly includes a plurality of electrode structures and diaphragms as described in any one of claims 1 to 10, wherein the diaphragms are disposed on opposite sides of the electrode structures and cover the through grooves.

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