Pole piece coating device

Abstract

The utility model discloses a pole piece coating device which is used for coating electrode slurry in a coating area of a current collector and coating insulating liquid in a blank area of the current collector. The pole piece coating device comprises a transmission mechanism for transmitting the current collector along the transmission direction, a coating head for synchronously coating the electrode slurry and the insulating liquid, and a curing lamp comprising a support frame and an irradiation part for emitting curing light, and the coating head is arranged in a transmission path of the transmission mechanism. One end part of the support frame is connected with the coating head, the other end part of the support frame is fixedly connected with the irradiation part, the irradiation part is positioned at the downstream of the coating head along the transmission direction, and the blank area coated with the insulating liquid is positioned in the irradiation area of the irradiation part. The pole piece coating device can effectively avoid mutual permeation of the electrode slurry and the insulating liquid.

Description

Technical Field

[0001] This utility model belongs to the field of electrode coating technology, specifically relating to an electrode coating device. Background Technology

[0002] Lithium-ion batteries, as a new energy battery, have advantages such as high operating voltage, high specific capacity, long charge / discharge life, and no memory effect. Lithium-ion batteries are gradually becoming the mainstream energy choice, leading to increasing demand. Simultaneously, the safety of lithium-ion batteries is becoming a growing concern. During the daily manufacturing process, abnormal cells may exhibit issues such as short circuits during assembly (zero resistance), low formation voltage, high self-discharge, and large module voltage differences. Disassembly of finished batteries has revealed that the separator corresponding to the blank edge of the positive electrode plate has been punctured. Analysis shows that metal particles generated during laser cutting sputter into the blank area, causing foreign objects to puncture the separator. This can lead to a large voltage difference within the cell, or even a short circuit and serious accidents. Furthermore, bending the tabs during cell assembly can cause the base of the tab to contact the blank edge of the electrode plate, also resulting in a short circuit.

[0003] Current manufacturing processes for square lithium-ion batteries mostly involve coating with a blank area, laser cutting the electrode tabs, and then winding. Traditional laser cutting typically involves directly cutting the foil to reduce dust, leaving a 0.5-1mm blank area at the edge of the material area. Direct cutting often results in metal particles sputtering into the blank area. Current methods involve coating the blank edge with an insulating liquid. For example, Chinese patent CN114656918A discloses an insulating liquid and its preparation method for coating the blank edge of the positive electrode sheet in lithium-ion batteries. It proposes using polyimide, polyvinylidene fluoride, N-methylpyrrolidone, and insulating carbon black to form the insulating liquid. During production, the positive electrode slurry and the insulating liquid are coated simultaneously, and the two are in contact in a liquid state. While this method provides good insulation protection, it is prone to interpenetration, which reduces battery capacity. Utility Model Content

[0004] The purpose of this invention is to address the problem of mutual penetration when electrode paste and insulating liquid are coated simultaneously in the prior art, and to provide an electrode coating device that can avoid mutual penetration.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is: an electrode coating device for coating electrode paste in the coating area of ​​a current collector and coating insulating liquid in the blank area of ​​the current collector, the electrode coating device comprising:

[0006] The transmission mechanism conveys the current collector along the transmission direction;

[0007] A coating head is disposed in the transmission path of the transmission mechanism, and the coating head is used to simultaneously coat the electrode slurry and the insulating liquid;

[0008] A curing lamp includes a support frame and an irradiation section for emitting curing light. One end of the support frame is connected to the coating head, and the other end of the support frame is fixedly connected to the irradiation section. The irradiation section is located downstream of the coating head along the transmission direction, and the blank area coated with the insulating liquid is located within the irradiation area of ​​the irradiation section.

[0009] In some embodiments, the curing lamp is an ultraviolet curing lamp, and the irradiation section is used to emit ultraviolet light.

[0010] In some embodiments, the irradiation portion includes a plurality of light-emitting elements spaced apart along its own length, and the power of the plurality of light-emitting elements gradually increases along the transmission direction.

[0011] In some embodiments, the irradiation portion is provided with multiple rows of light-emitting components spaced apart along its own length direction, each row of light-emitting components including multiple light-emitting elements, and the power of the light-emitting elements gradually increases along the transmission direction.

[0012] In some embodiments, the current collector, after being coated by the coating head, is transported along a first direction extending horizontally, and the support frame is slidably connected to the coating head along a second direction, which is perpendicular to the first direction.

[0013] In some embodiments, the coating head is provided with a groove extending along the second direction, the support frame has a connecting portion, the connecting portion and the irradiation portion are located at opposite ends of the support frame, and the connecting portion is slidably inserted into the groove.

[0014] In some embodiments, one sidewall of the slide is provided with a plurality of toothed grooves, the plurality of toothed grooves are arranged at equal intervals along the second direction at a first spacing, the connecting portion is provided with a limiting structure, the limiting structure is inserted in the toothed grooves, and the limiting structure is configured to be able to move between the plurality of toothed grooves.

[0015] In some embodiments, the coating head is provided with multiple scale lines, which are arranged at equal intervals along the second direction at a second spacing.

[0016] In some embodiments, the coating head is provided with the toothed groove and the scale line, the first spacing is equal to the second spacing, and the scale line corresponds to the position of the toothed groove.

[0017] In some embodiments, the current collector, after being coated by the coating head, is transported along a first direction extending horizontally. The support frame includes multiple support rods, with two adjacent support rods rotatably connected about a rotation center line extending along a second direction perpendicular to the first direction. A locking structure for locking the two adjacent support rods is provided between them.

[0018] In some embodiments, the two adjacent support rods are a first support rod and a second support rod, and the locking structure includes:

[0019] A fixing ring having a central hole is fixedly mounted on the first support rod;

[0020] A locking element, wherein the locking element is an arc extending around the rotation center line, the locking element is slidably inserted into the fixing ring, and limiting portions are fixed at both ends of the locking element, the width of the limiting portions being greater than the diameter of the central hole;

[0021] A tightening bolt is threadedly connected to the retaining ring, and at least a portion of the tightening bolt can extend into the central hole;

[0022] When the locking structure is in the locked state, the locking member is pressed against the wall between the tightening bolt and the center hole, and the limiting part abuts against the second support rod; or, the limiting part includes a first limiting part near the second support rod and a second limiting part away from the second support rod, the first limiting part being fixedly connected to the second support rod, and when the locking structure is in the locked state, the locking member is pressed against the wall between the tightening bolt and the center hole.

[0023] In some embodiments, the locking element is a semi-circular arc extending about the rotation center line.

[0024] Due to the application of the above technical solution, this utility model has the following advantages compared with the prior art: The electrode coating device of this utility model simultaneously coats the electrode slurry on the coating area and the insulating liquid on the blank area through the coating head, resulting in higher coating efficiency. Furthermore, after coating and before drying in the oven, the insulating slurry coated on the blank area is irradiated with a curing lamp, causing the insulating liquid to cure rapidly and preventing interpenetration between the electrode slurry and the insulating liquid. Moreover, curing by the curing lamp also prevents diffusion between the electrode slurry and the insulating liquid at the interface during drying in the oven. Attached Figure Description

[0025] Appendix Figure 1 This is a schematic diagram of a portion of the electrode coating device according to Embodiment 1 of this utility model;

[0026] Appendix Figure 2 For the appendix Figure 1 Schematic diagram of the curing lamp and guide block;

[0027] Appendix Figure 3 For the appendix Figure 2 A schematic diagram of the guide block;

[0028] Appendix Figure 4 This is a schematic diagram of the irradiation section in Example 1;

[0029] Appendix Figure 5 This is a partial structural schematic diagram of the electrode coating device in Embodiment 2 of this utility model;

[0030] Appendix Figure 6 For the appendix Figure 5 Schematic diagram of the curing lamp and guide block;

[0031] Appendix Figure 7 For the appendix Figure 6 Enlarged view of point A in the middle;

[0032] Appendix Figure 8 This is a partial structural schematic diagram of the electrode coating device in Embodiment 3 of this utility model;

[0033] Appendix Figure 9 This is a schematic diagram of the irradiation section in Example 3;

[0034] The components are as follows: 10. Current collector; 11. First roller; 12. Second roller; 2. Coating head; 20. Main body; 21. Guide block; 211. Slide groove; 212. Tooth groove; 22. Slide rail; 3. Curing lamp; 31. Support frame; 311. Connecting part; 312. Support rod; 32. Irradiation part; 321. Light-emitting element; 41. Fixing ring; 411. Center hole; 42. Locking element; 421. Limiting part; 43. Tightening bolt. Detailed Implementation

[0035] The technical solution of this utility model will be described in detail below with reference to the accompanying drawings and specific embodiments, so that the advantages and features of this utility model can be more easily understood by those skilled in the art. Obviously, the embodiments described in this application are only a part of the embodiments, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments in this application without creative effort are within the scope of protection of this application.

[0036] When coating electrodes, specifically when coating the current collector of a lithium battery positive electrode with electrode slurry and insulating liquid, the electrode slurry and insulating liquid are in liquid contact before drying, which can easily lead to interpenetration. This invention provides a novel coating apparatus that, after coating and before drying, uses a curing lamp to cure the insulating liquid, thus preventing interpenetration between the insulating liquid and the electrode slurry.

[0037] Example 1

[0038] See Figure 1 An electrode coating apparatus is shown, used to coat electrode slurry in the coating area of ​​a current collector 10 and to coat insulating liquid in the blank area of ​​the current collector 10. The electrode coating apparatus includes a conveying mechanism, a coating head 2, and a curing lamp 3. The conveying mechanism is used to transport the current collector 10 along the conveying direction. The coating head 2 is disposed in the conveying path of the conveying mechanism and is used to simultaneously coat the electrode slurry and insulating liquid, improving coating efficiency. The curing lamp 3 includes a support frame 31 and an irradiation section 32 for emitting curing light. The support frame 31 is connected to the coating head 2, and the irradiation section 32 is fixedly connected to the support frame 31. The irradiation section 32 is located downstream of the coating head 2 along the conveying direction, and the blank area coated with the insulating liquid is located within the irradiation area of ​​the irradiation section 32.

[0039] After the coating head 2 completes the coating process on the current collector 10, the irradiation unit 32 can cure the insulating liquid coated on the blank area, allowing the insulating liquid to cure quickly and thus preventing the insulating liquid from interpenetrating with the electrode paste. In this embodiment, the insulating liquid is a coating that can be cured using ultraviolet light, the curing lamp 3 is an ultraviolet curing lamp 3, and the irradiation unit 32 is used to emit ultraviolet light.

[0040] In this embodiment, the conveying mechanism includes multiple conveying rollers, which drive the current collector 10 to move forward along the conveying direction by rotating the conveying rollers. See also... Figure 1 As shown, the transfer roller includes a first roller 11 and a second roller 12, wherein the first roller 11 is disposed opposite to the coating head 2, and the current collector 10 is located between the first roller 11 and the coating head 2.

[0041] In this embodiment, the current collector 10, after being coated by the coating head 2, is transported along a first horizontal direction, and the irradiation part 32 also extends along the first direction. The irradiation part 32 has a preset length to meet the irradiation energy required for the curing of the insulating liquid.

[0042] In this embodiment, see Figure 4As shown, the irradiation unit 32 includes a plurality of light-emitting elements 321 spaced apart along its own length. The power of the plurality of light-emitting elements 321 gradually increases along the transmission direction. The irradiation intensity received by the insulating liquid gradually increases during the forward transmission process. Compared with high-intensity ultraviolet light directly irradiating the freshly coated insulating liquid, gradually increasing the irradiation intensity can achieve a better curing effect.

[0043] Specifically, in this embodiment, the light-emitting element 321 is a lamp bead capable of emitting ultraviolet light. The lamp bead is replaceable, which facilitates adjustment of the irradiation intensity and maintenance. The lamp bead is equipped with a focusing lens to focus the emitted light and concentrate the ultraviolet light onto the insulating liquid, thereby achieving a better curing effect.

[0044] See Figure 1 As shown, in this embodiment, the coating head 2 extends along a second direction, which is perpendicular to the first direction and parallel to the width direction of the current collector. The support frame 31 is connected to one side of the coating head 2 along the second direction. The irradiation unit 32 is located above the current collector 10. Specifically, the irradiation unit 32 is located above the blank area coated with insulating liquid. The irradiation unit 32 emits ultraviolet light downwards and cures the insulating liquid below.

[0045] In this embodiment, the support frame 31 is slidably mounted on the coating head 2 along the second direction. The operator can adjust the position of the irradiation section 32 along the second direction by sliding the support frame 31, so that the blank area coated with insulating liquid falls accurately into the irradiation area. The electrode coating device of this embodiment can be applied to current collectors 10 of different sizes. When coating current collectors 10 of different sizes, the irradiation section 32 is accurately positioned above the blank area coated with insulating liquid by sliding the support frame 31.

[0046] Specifically, in this embodiment, the coating head 2 is provided with a groove 211 extending along the second direction, and the support frame 31 has a connecting part 311. The connecting part 311 and the irradiation part 32 are respectively disposed at opposite ends of the support frame 31, and the connecting part 311 is slidably inserted into the groove 211. Specifically, the coating head 2 includes a main body 20 for coating treatment, and a guide block 21 is fixedly provided on the upper part of the main body 20. The guide block 21 has a groove 211. The sliding connection between the support frame 31 and the coating head 2 is realized through the cooperation between the groove 211 and the connecting part 311, and the groove 211 provides motion guidance for the sliding of the support frame 31.

[0047] In this embodiment, along the first direction, a plurality of toothed grooves 212 are provided on one side wall of the slide groove 211. The plurality of toothed grooves are arranged at equal intervals along the second direction. The connecting part 311 is provided with a limiting structure, which is inserted into the toothed grooves 212 and is configured to move between the plurality of toothed grooves 212. Through the cooperation between the limiting mechanism and the toothed grooves 212, the operator can adjust the position of the support frame 31 in units of toothed grooves 212, thereby improving the adjustment accuracy. For example, in some embodiments, the distance between two adjacent toothed grooves 212 is 1 mm. Each time the limiting structure moves one toothed groove 212, the support frame 31 translates 1 mm along the second direction. The limiting structure can adopt a combination structure of elastic element and limiting pin, wherein the limiting pin is movably set along the first direction, and the elastic element is used to provide the force required to drive the limiting pin to move towards the toothed grooves 212. Alternatively, the limiting structure can adopt other structures in the prior art that can achieve the above functions, which will not be elaborated here.

[0048] In this embodiment, the coating head 2 is provided with multiple graduation lines spaced apart along the second direction, and the support frame 31 is provided with indicator marks. Specifically, see Figure 3 As shown, scale lines are set on the upper surface of the guide block 21, and the scale lines are located on the side of the slide groove 211 away from the tooth groove 212 along the first direction. Multiple scale lines are set at equal intervals along the second direction. Indicator marks are set on the connecting part 311 of the support frame 31. The indicator marks are indicator lines extending in the vertical direction. The position of the support frame 31 can be better determined by the scale lines and indicator marks, and the moving distance of the support frame 31 can be better determined during the sliding of the support frame 31. In this embodiment, the spacing between two adjacent scale lines is the same as the spacing between two adjacent tooth grooves 212, which facilitates the operator to adjust the position of the support frame 31.

[0049] In this embodiment, the support frame 31 includes multiple support rods 312. Adjacent support rods 312 are rotatably connected around a rotation center line extending in a second direction. A locking structure is provided between adjacent support rods 312 to lock them together. By rotating the support rods 312, the angle between adjacent support rods 312 changes, thereby adjusting the height of the irradiation section 32, thus changing the size of the irradiation area and the irradiation intensity. Simultaneously, adjusting the support rods 312 also adjusts the position of the irradiation section 32 along the first direction, thereby adjusting the distance between the irradiation area and the working area of ​​the coating head 2. After adjusting the support rods 312, the locking structure is used to lock them, thereby maintaining the stability of the support frame 31.

[0050] In this embodiment, see Figure 2As shown, the support frame 31 includes three support rods 312. The first support rod 312 extends vertically and has a connecting part 311 at its lower part. One end of the second support rod 312 is fixedly connected to the irradiation part 32. One end of the third support rod 312 is rotatably connected to the second support rod 312, and the other end of the third support rod 312 is rotatably connected to the upper part of the first support rod 312. In this embodiment, the locking structure is a screw connected between two adjacent support rods 312. Locking between the two support rods 312 is achieved by tightening the screw.

[0051] Example 2

[0052] See Figures 5 to 7 As shown, the main difference between this embodiment and Embodiment 1 lies in the different locking structure configuration. Specifically, in this embodiment, the two adjacent support rods 312 are the first support rod and the second support rod, respectively. The locking structure includes a fixing ring 41, a locking element 42, and a tightening bolt 43. See also... Figure 7 As shown, the retaining ring 41 has a central hole 411 and is fixed to the first support rod. The locking member 42 is an arc extending about the rotation center line. The locking member 42 is slidably inserted into the retaining ring 41. Limiting portions 421 are fixed at both ends of the locking member 42, and the width of the limiting portions 421 is greater than the diameter of the central hole 411. The tightening bolt 43 is threadedly connected to the retaining ring 41, and at least part of the tightening bolt 43 can extend into the central hole 411. When the locking structure is in the locked state, the locking member 42 is pressed against the wall of the central hole 411 between the tightening bolt 43 and the hole, and the limiting portions 421 abut against the second support rod.

[0053] During the adjustment of the support rod 312, when the limiting part 421 abuts against the fixing ring 41, the locking member 42 cannot slide relative to the fixing ring 41, thereby limiting the rotation angle of the locking member 42 relative to the first support rod, and thus limiting the relative rotation angle between the first support rod and the second support rod. When the locking structure is in the locked state, the locking member 42 is fixed relative to the first support rod, and the limiting part 421 abuts against the second support rod, thereby preventing the first support rod from moving closer to the second support rod, thus maintaining stability between the first support rod and the second support rod.

[0054] When adjusting the support rod, first rotate the tightening bolt 43 to release the locking member 42 from the hole wall of the center hole 411. At this time, the locking member 42 can slide relative to the fixing ring 41, and the first support rod and the second support rod can also rotate relative to each other. After the first support rod and the second support rod are adjusted into place, drive the limiting part 421 to abut against the second support rod and rotate the tightening bolt 43 in the opposite direction to fix the locking member 42 to the first support rod, thus completing the locking of the first support rod and the second support rod.

[0055] In some embodiments, the locking member 42 is fixedly connected to the second support rod. Specifically, the two limiting portions 421 are a first limiting portion closer to the second support rod and a second limiting portion farther from the second support rod, respectively, with the first limiting portion fixedly connected to the second support rod. When the locking structure is in the unlocked state, during the process of driving the second support rod to rotate relative to the first support rod, the second support rod drives the locking member 42 to rotate together around the rotation center line, and the locking member 42 slides relative to the fixed ring 41. By rotating the tightening bolt 43 to clamp and fix the locking member 42, the locking structure can be driven to switch to the locked state.

[0056] In this embodiment, the locking member 42 is a semi-circular arc extending around the rotation center line, and the maximum rotation angle between the first support rod and the second support rod is 180 degrees.

[0057] Example 3

[0058] See Figure 8 , Figure 9 As shown, the main difference between this embodiment and Embodiment 1 is that in this embodiment, the irradiation unit 32 is provided with multiple rows of light-emitting components spaced apart along its own length direction. Each row of light-emitting components includes multiple light-emitting elements 321 spaced apart, and the power of the light-emitting elements 321 gradually increases along the first direction. In this embodiment, the upper part of the coating head 2 is provided with a slide rail 22 extending along the second direction, and the connecting part 311 is slidably disposed on the slide rail 22.

[0059] Example 4

[0060] Without illustrations, the main difference between this embodiment and Embodiments 1 and 2 is that: in this embodiment, the locking structure includes the screw provided between two adjacent support rods 312 as in Embodiment 1, and the locking structure also includes the fixing ring 41, locking member 42 and tightening bolt 43 as in Embodiment 2. After locking with this locking structure, the stability of the support frame 31 is better.

[0061] In summary, the electrode coating apparatus of all the above embodiments has the following advantages:

[0062] 1) By setting the curing lamp 3, the insulating liquid is quickly cured after the coating head 2 has finished coating the current collector 10, which effectively avoids the mutual penetration between the electrode paste and the insulating liquid during the transfer to the oven.

[0063] 2) Effectively prevents the electrode paste and insulating liquid from diffusing at the interface during the drying process;

[0064] 3) The support frame 31 can slide along the second direction, and the electrode coating device can be applied to current collectors 10 of different sizes.

[0065] The above embodiments are only for illustrating the technical concept and features of this utility model, and are intended to enable those skilled in the art to understand the content of this utility model and implement it accordingly. They should not be construed as limiting the scope of protection of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this utility model should be included within the scope of protection of this utility model.

Claims

1. An electrode coating apparatus for coating an electrode paste in a coating area of ​​a current collector and coating an insulating liquid in a blank area of ​​the current collector, characterized in that: The electrode coating apparatus includes: The transmission mechanism conveys the current collector along the transmission direction; A coating head is disposed in the transmission path of the transmission mechanism, and the coating head is used to simultaneously coat the electrode slurry and the insulating liquid; A curing lamp includes a support frame and an irradiation section for emitting curing light. One end of the support frame is connected to the coating head, and the other end of the support frame is fixedly connected to the irradiation section. The irradiation section is located downstream of the coating head along the transmission direction, and the blank area coated with the insulating liquid is located within the irradiation area of ​​the irradiation section.

2. The electrode coating apparatus according to claim 1, characterized in that: The curing lamp is an ultraviolet curing lamp, and the irradiation part is used to emit ultraviolet light.

3. The electrode coating apparatus according to claim 1, characterized in that: The irradiation unit includes a plurality of light-emitting elements spaced apart along its own length, and the power of the plurality of light-emitting elements gradually increases along the transmission direction; Alternatively, the irradiation section may be provided with multiple rows of light-emitting components spaced apart along its own length, each row of light-emitting components including multiple light-emitting elements, and the power of the light-emitting elements gradually increases along the transmission direction.

4. The electrode coating apparatus according to claim 1, characterized in that: The current collector, after being coated by the coating head, is transported along a first horizontal direction, and the support frame is slidably connected to the coating head along a second direction, which is perpendicular to the first direction.

5. The electrode coating apparatus according to claim 4, characterized in that: The coating head is provided with a groove extending along the second direction, and the support frame has a connecting part. The connecting part and the irradiation part are located at opposite ends of the support frame, and the connecting part is slidably inserted into the groove.

6. The electrode coating apparatus according to claim 5, characterized in that: The sidewall of the slide is provided with a plurality of toothed grooves, which are arranged at equal intervals along the second direction at a first spacing. The connecting part is provided with a limiting structure, which is inserted into the toothed grooves and is configured to move between the plurality of toothed grooves. And / or, the coating head is provided with multiple scale lines, which are arranged at equal intervals along the second direction at a second spacing.

7. The electrode coating apparatus according to claim 6, characterized in that: The coating head is provided with the toothed groove and the scale line, the first spacing is equal to the second spacing, and the scale line corresponds to the position of the toothed groove.

8. The electrode coating apparatus according to claim 1, characterized in that: The current collector, after being coated by the coating head, is transported along a first horizontally extending direction. The support frame includes multiple support rods, with two adjacent support rods rotatably connected around a rotation center line. The rotation center line extends along a second direction, which is perpendicular to the first direction. A locking structure is provided between two adjacent support rods to lock them together.

9. The electrode coating apparatus according to claim 8, characterized in that: The two adjacent support rods are a first support rod and a second support rod, and the locking structure includes: A fixing ring having a central hole is fixedly mounted on the first support rod; A locking element, wherein the locking element is an arc extending around the rotation center line, the locking element is slidably inserted into the fixing ring, and limiting portions are fixed at both ends of the locking element, the width of the limiting portions being greater than the diameter of the central hole; A tightening bolt is threadedly connected to the retaining ring, and at least a portion of the tightening bolt can extend into the central hole; When the locking structure is in the locked state, the locking member is pressed against the wall between the tightening bolt and the center hole, and the limiting part abuts against the second support rod; or, the limiting part includes a first limiting part near the second support rod and a second limiting part away from the second support rod, the first limiting part being fixedly connected to the second support rod, and when the locking structure is in the locked state, the locking member is pressed against the wall between the tightening bolt and the center hole.

10. The electrode coating apparatus according to claim 9, characterized in that: The locking element is a semi-circular arc extending around the rotation center line.

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