Coating die head and coating equipment

Abstract

The utility model relates to the technical field of battery manufacturing equipment, and discloses a coating die head and coating equipment. The coating die head comprises a die head assembly, the die head assembly comprises a first die head, a second die head and a third die head which are stacked in sequence, and a discharging end is formed at one end of the die head assembly in the direction perpendicular to the stacking direction of the first die head, the second die head and the third die head; the first gasket is clamped between the first die head and the second die head, the first gasket is provided with a first discharging opening facing an opening of the discharging end, the total thickness of the first gasket is H1mm, and the opening width of the first discharging opening is L1mm; the second gasket is clamped between the second die head and the third die head, the second gasket is provided with a second discharging opening facing an opening of the discharging end, the total thickness of the second gasket is H2mm, and the opening width of the second discharging opening is L2 mm; wherein H1 and H2 meet the condition that H1 is larger than H2, and L1 and L2 meet the condition that L1 is larger than L2. And two kinds of slurry can be discharged from the discharging end, so that double-layer coating of the pole piece is realized.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery manufacturing equipment technical field, concretely relates to coating die head and coating equipment. BACKGROUND

[0002] In the battery production manufacturing process, the coating equipment is used for the coating processing of the pole piece, and the coating die head is an important component of the coating equipment. The coating equipment coats the material on the foil of the pole piece through the coating die head. The coating die head in the prior art is usually composed of two die heads and a gasket clamped between the adjacent two die heads. The die head is used to provide the material, and the gasket is provided with a discharge port. The gasket is used to control the width and thickness of the discharge. Some pole pieces need to be coated with two different materials, i.e. double-layer coating. However, the coating die head in the prior art can usually only be used for single-layer coating of the pole piece. For the pole piece that needs double-layer coating and the composition of the coated material is different, the die head or the gasket needs to be replaced after coating the first layer of material, and then the second layer of material is coated. The coating die head cannot simultaneously perform double-layer coating on the pole piece. The single coating die head is not convenient for realizing double-layer coating on the pole piece, the processing efficiency is low, the cost is high, and the product competitiveness is not improved. SUMMARY

[0003] Therefore, the utility model provides a kind of coating die head and coating equipment to solve the problem that coating die head is not convenient for realizing double-sided coating of pole piece.

[0004] In the first aspect, the utility model provides a kind of coating die head, comprising: die head assembly, including first die head, second die head and third die head that are stacked in sequence, in the stacking direction perpendicular to the first die head, second die head and third die head, one end of the die head assembly forms discharge end;First gasket, clamped between the first die head and the second die head, first gasket is provided with first discharge port that opens towards the discharge end, the total thickness of the first gasket is H1 mm, the opening width of the first discharge port is L1 mm;Second gasket, clamped between the second die head and the third die head, second gasket is provided with second discharge port that opens towards the discharge end, the total thickness of the second gasket is H2 mm, the opening width of the second discharge port is L2 mm;Wherein, H1 and H2 satisfy: H1> H2, L1 and L2 satisfy: L1> L2.

[0005] Beneficial effects: By setting the die assembly to be stacked by the first die, the second die and the third die, and a gasket is arranged between the adjacent two setting dies, the position of each gasket corresponds to the output of one kind of slurry, so that two kinds of slurry can be output at the discharge end, two kinds of slurry can be coated on the pole piece at the same time, that is, double-layer coating of the pole piece is realized, which is beneficial to improve the processing efficiency. By setting the thickness of the first gasket and the second gasket to be different, the surface density of the two-layer coating slurry is realized, the actual demand is met, and by setting the thickness of the first gasket to be greater than the thickness of the second gasket, and the opening width of the first discharge port on the first gasket is greater than the opening width of the second discharge port on the second gasket, it is ensured that the upper film area corresponding to the first gasket can cover the lower film area corresponding to the second gasket, and the cleanliness of the film layer appearance is ensured, which is convenient for detecting whether the coating film layer is qualified.

[0006] In an optional embodiment, the opening width L1 mm of the first discharge port and the opening width L2 mm of the second discharge port satisfy the relationship: 0.5≤L1-L2≤3.

[0007] Beneficial effects: It can not only ensure that the first film area formed by the first discharge port can stably cover the second film area formed by the second discharge port, but also avoid that the first film area exceeds the second film area by too much size, so as to avoid waste of materials and save costs.

[0008] In an optional embodiment, the first gasket comprises a first connecting portion and at least two first extension portions, the first extension portion is extended from a part of the area on the side of the first connecting portion to the direction close to the discharge end, and the first discharge port is formed between the adjacent two first extension portions; the second gasket comprises a second connecting portion and at least two second extension portions, the second extension portion is extended from a part of the area on the side of the second connecting portion to the direction close to the discharge end, and the second discharge port is formed between the adjacent two second extension portions.

[0009] Beneficial effects: By setting the first gasket to be composed of the first connecting portion and the at least two first extension portions connected to the first connecting portion, the first discharge port is formed between the adjacent two first extension portions, so that the first gasket has at least one first discharge port, which is convenient for the slurry between the first die and the second die to be discharged from the first discharge port, thereby realizing the coating of the slurry; by setting the second gasket to be composed of the second connecting portion and the at least two second extension portions connected to the second connecting portion, the second discharge port is formed between the adjacent two second extension portions, which is convenient for the slurry between the second die and the third die to be discharged from the second discharge port, thereby realizing the coating of the slurry.

[0010] In one optional embodiment, the first extension has a first chamfer and a wing at the end away from the first connecting portion. The first chamfer is located at the corner of the first extension facing the first discharge port. The first chamfer is formed by a portion of the upper surface of the first extension being recessed downwards. The wing is connected to the side of the first extension facing the first discharge port. The end of the wing away from the first connecting portion is flush with the end of the first extension away from the first connecting portion. The thickness of the first chamfer is H12 mm, and the thickness of the wing is H11 mm, wherein H11 < H12 < H1.

[0011] Beneficial effects: By constructing a first chamfer and a flying wing at the end of the first extension away from the first connection, and the first chamfer and the flying wing are both at the corner of the first extension facing the first outlet, and the total thickness H1 mm of the first gasket, the thickness H11 mm of the flying wing 140, and the thickness H12 mm of the first chamfer 130 satisfy the relationship H11 < H12 < H1, the flying wing thins the thickness of the first slurry flowing out of the first outlet, and the first chamfer guides and further thins the thickness of the first slurry, thereby reducing the amount of slurry at the edge along the second direction, reducing the edge thickness of the first film layer formed by the first slurry, and forming a thinning zone at the edge position of the first film layer along the second direction, effectively avoiding the phenomenon of bulging and cracking of the electrode, improving the electrode yield and battery safety.

[0012] In one optional embodiment, the maximum dimension of the first chamfered portion along the extension direction of the first connecting portion is A mm, and the maximum dimension of the first chamfered portion along the extension direction of the first extension portion is B mm, wherein the extension direction of the first connecting portion is perpendicular to the extension direction of the first extension portion, and the value range of A is 0.5-5, and the value range of B is 0.5-5.

[0013] Beneficial effects: The first chamfered portion has a reasonable size, which can ensure that the thinning area on both sides of the first film layer formed by the first slurry flowing out of the first outlet has a reasonable width, avoiding insufficient thinning area size or material waste, and can also ensure the stability of the first slurry when flowing through the first chamfered portion and the structural strength of the first chamfered portion.

[0014] In one optional embodiment, the dimension of the flying wing along the extension direction of the first connecting portion is C mm, and the dimension of the flying wing along the extension direction of the first extension portion is D mm, wherein the value of C ranges from 1 to 10, and the value of D ranges from 3 to 50.

[0015] And / or, the total thickness H1 mm of the first gasket, the thickness H12 mm of the first chamfer, and the thickness H11 mm of the flying wing satisfy the following relationship: H12 / H1 = 2 / 3, H11 / H1 = 1 / 3.

[0016] Beneficial effects: By setting the dimension C of the flying wing along the extension direction of the first connecting part to a value in the range of 1-10, and the dimension D of the flying wing along the extension direction of the first extension part to a value in the range of 3-50, the flying wing has a reasonable size. This ensures that the thinning area has a reasonable size along the second direction, avoiding insufficient size of the thinning area or insufficient surface density of the electrode sheet. It also ensures the thinning effect of the flying wing on the first film layer near the edge, ensuring the thinning effect, and ensuring the structural strength of the flying wing itself, thus improving reliability.

[0017] By setting the thickness of the three components to satisfy the relationship H12 / H1=2 / 3 and H11 / H1=1 / 3, the thickness of the first gasket body, the first chamfer, and the flying wing are arranged in a stepped shape with decreasing thickness. This facilitates the control of the dimensions of each part during the processing and helps to improve processing accuracy and efficiency.

[0018] In one alternative embodiment, a second chamfer is formed at one end of the second extension away from the second connecting portion. The second chamfer is located at the corner of the second extension on the side facing the second discharge port, and the second chamfer is formed by a portion of the upper surface of the second extension being recessed downward.

[0019] Beneficial effects: By constructing a second chamfer at the corner of the second extension facing the second outlet, and the second chamfer being formed by a portion of the upper surface of the second extension being recessed downwards, the thickness of the second chamfer is less than the thickness of the second extension. The second chamfer guides and thins the second slurry flowing out of the second outlet, thereby reducing the amount of slurry at both edges along the second direction and reducing the edge thickness of the second film layer formed by the second slurry. This creates a thinning zone at both edges of the second film layer along the second direction, further preventing bulging and cracking of the electrode, improving electrode yield and battery safety.

[0020] In one optional embodiment, the maximum dimension of the second chamfered portion along the extension direction of the second connecting portion is E mm, and the maximum dimension of the second chamfered portion along the extension direction of the second extension portion is F mm, wherein the extension direction of the second connecting portion is perpendicular to the extension direction of the second extension portion, the value of E is in the range of 1-5, and the value of F is in the range of 0.5-5.

[0021] And / or, the thickness of the second chamfer is H21 mm, wherein H21 mm and the total thickness H2 mm of the second gasket satisfy the relationship: H21 / H2=1 / 2.

[0022] Beneficial effects: By setting the maximum dimension E of the second chamfered portion along the extension direction of the second connecting portion to be within the range of 1-5, and the maximum dimension F of the second chamfered portion along the extension direction of the second extension portion to be within the range of 0.5-5, the second chamfered portion has a reasonable size, ensuring that the thinning area on both sides of the second film layer formed by the second slurry flowing out of the second outlet along the second direction has a reasonable width, avoiding insufficient electrode surface density, ensuring the thinning effect and that the second chamfered portion has sufficient structural strength, and improving reliability.

[0023] By setting the thickness H21 mm of the second chamfer to satisfy the relationship H21 / H2 = 1 / 2 with the total thickness H2 mm of the second shim, the thickness of the second chamfer is ensured to be less than the total thickness of the second shim. The body of the second shim and the second chamfer are stepped, which facilitates the control of the dimensions of the second chamfer during the processing and helps to improve the processing accuracy and efficiency.

[0024] In one alternative embodiment, the maximum dimension E mm of the second chamfered portion along the extension direction of the second connecting portion and the maximum dimension A mm of the first chamfered portion along the extension direction of the first connecting portion satisfy the relationship: E > A.

[0025] Beneficial effects: By setting the width E mm of the chamfered part of the second gasket to satisfy the relationship E > A mm with the width A mm of the chamfered part of the first gasket, a width difference is ensured between the first film layer and the second film layer, achieving a thinning width ≤ 8 mm. This avoids the overall film area from having an excessively large width or thickness at the edge along the second direction, thus preventing the thinning area from being too wide or the electrode from exceeding the thickness requirement.

[0026] Secondly, this utility model also provides a coating device, including the aforementioned coating die. Since the coating device includes a coating die and has the same effects as the coating die, it will not be described in detail here. Attached Figure Description

[0027] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0028] Figure 1This is an exploded view of a coating die head according to an embodiment of the present utility model;

[0029] Figure 2 for Figure 1 An exploded view of the coating die head from another perspective;

[0030] Figure 3 for Figure 1 A side view of the assembly diagram of the coating die head shown;

[0031] Figure 4 This is a schematic diagram of the structure of a first gasket according to an embodiment of the present utility model;

[0032] Figure 5 for Figure 4 A magnified view of a portion of G;

[0033] Figure 6 for Figure 4 A top view of the first gasket shown;

[0034] Figure 7 for Figure 6 A magnified view of part of K;

[0035] Figure 8 for Figure 7 A partial front view of the first gasket shown;

[0036] Figure 9 for Figure 4 The diagram shown is a partially enlarged view of the first gasket, including a first discharge port.

[0037] Figure 10 This is a schematic diagram of the structure of a second gasket according to an embodiment of the present utility model;

[0038] Figure 11 for Figure 10 A magnified view of part M in the diagram;

[0039] Figure 12 for Figure 10 Top view of the second gasket shown

[0040] Figure 13 for Figure 12 A magnified view of N in the diagram;

[0041] Figure 14 for Figure 13 A partial front view of the second gasket shown;

[0042] Figure 15 for Figure 10 The diagram shown is a partially enlarged view of the first gasket, including a second discharge port.

[0043] Explanation of reference numerals in the attached figures:

[0044] 1. First gasket; 101. First discharge port; 110. First connecting part; 120. First extension part; 130. First chamfered part; 140. Flying wing; 2. Second gasket; 201. Second discharge port; 210. Second connecting part; 220. Second extension part; 230. Second chamfered part; 3. Die head assembly; 301. First die head; 302. Second die head; 303. Third die head; 310. Discharge end. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0046] The following is combined with Figures 1 to 15 The following describes embodiments of the present invention.

[0047] According to an embodiment of the present invention, a coating die head is provided, comprising: a die head assembly 3, a first gasket 1, and a second gasket 2. The die head assembly 3 includes a first die head 301, a second die head 302, and a third die head 303 stacked sequentially. In the stacking direction perpendicular to the first die head 301, the second die head 302, and the third die head 303, one end of the die head assembly 3 forms a discharge end 310. A first gasket 1 is sandwiched between the first die head 301 and the second die head 302. The first gasket 1 has a first discharge port 101 opening towards the discharge end 310. The total thickness of the first gasket 1 is H1 mm, and the opening width of the first discharge port 101 is L1 mm. A second gasket 2 is sandwiched between the second die head 302 and the third die head 303. The second gasket 2 has a second discharge port 201 opening towards the discharge end 310. The total thickness of the second gasket 2 is H2 mm, and the opening width of the second discharge port 201 is L2 mm. Wherein, H1 and H2 satisfy: H1 > H2, and L1 and L2 satisfy: L1 > L2.

[0048] It should be noted that the first mold head 301, the second mold head 302, and the third mold head 303 of the mold head assembly 3 are configured according to... Figure 1 , Figure 3 The "up and down" direction indicated by the middle arrow indicates stacking from top to bottom; the discharge end 310 is located along... Figure 3The end indicated by the middle arrow, the "first direction," is the discharge end 310, used to discharge slurry, thereby coating the slurry onto the foil of the electrode sheet; the opening width of the first discharge port 101 or the second discharge port 201 refers to the width along the direction indicated by the middle arrow. Figure 1 The dimension of the "second direction" indicated by the middle arrow, wherein the second direction is perpendicular to the first direction.

[0049] The coating die head of this embodiment is configured by stacking a first die head 301, a second die head 302, and a third die head 303, with a spacer sandwiched between adjacent die heads. Each spacer corresponds to a different type of slurry, allowing two types of slurry to be discharged from the discharge end 310. This enables simultaneous coating of the electrode sheet with two types of slurry, achieving double-layer coating of the electrode sheet, which improves processing efficiency. By setting the thicknesses of the first spacer 1 and the second spacer 2 to be different, the areal densities of the two coating slurries are different, meeting practical requirements. Furthermore, by setting the thickness of the first spacer 1 to be greater than the thickness of the second spacer 2, and the opening width of the first discharge port 101 on the first spacer 1 to be greater than the opening width of the second discharge port 201 on the second spacer 2, it is ensured that the upper film area corresponding to the first spacer 1 can cover the lower film area corresponding to the second spacer 2, ensuring the cleanliness of the film appearance and facilitating the detection of whether the coated film layer is qualified.

[0050] It should be noted that the first gasket 1 corresponds to the first slurry, and the second gasket 2 corresponds to the second slurry. After the slurry is coated onto the foil of the electrode, it solidifies to form a first film layer and a second film layer. The first film layer is the upper film layer, and the second film layer is the lower film layer. The lower film layer formed by the second slurry is in contact with the foil, and the upper film layer formed by the first slurry covers the lower film layer, thus achieving double-layer coating of the electrode. The maximum thickness of the first film layer is the same as the thickness of the first gasket 1, and the maximum thickness of the second film layer is the same as the thickness of the second gasket 2. The two slurries discharged from the discharge end 310 have the same polarity but different materials; for example, the first gasket 1 corresponds to graphite slurry, and the second gasket 2 corresponds to silicon slurry. The electrode can be a positive electrode or a negative electrode.

[0051] Further integration Figure 3 As shown, the cross section of the second die head 302 parallel to the first direction is triangular, so that the second pad 2 is parallel to the first direction and the first pad 1 is set at an angle to the first direction, thereby making the discharge end 310 pointed to facilitate material discharge.

[0052] In one embodiment, the opening width L1 mm of the first outlet 101 and the opening width L2 mm of the second outlet 201 satisfy the relationship: 0.5 ≤ L1 - L2 ≤ 3. If L1 - L2 is less than 0.5, the difference between the opening widths of the first outlet 101 and the second outlet 201 is too small. Due to the fluidity of the slurry, the first film area formed by the material exiting from the first outlet 101 may not completely cover the second film area formed by the material exiting from the second outlet 201, thus making it difficult to ensure the stability of the coated film area and to detect whether the coated film area is qualified. If L1 - L2 is greater than 3, the difference between the opening widths of the first outlet 101 and the second outlet 201 is too large, and the size of the first film area extending beyond the sides of the second film area is too large, wasting materials and costs. Therefore, by setting the difference between the opening width L1 of the first discharge port 101 and the opening width L2 of the second discharge port 201 to be within the range of 0.5 to 3, it can be ensured that the first film area formed by the material discharged from the first discharge port 101 can stably cover the second film area formed by the material discharged from the second discharge port 201, while also preventing the first film area from exceeding the second film area by too much, thereby avoiding material waste and saving costs. Here, the width direction refers to along... Figure 1 The dimension in the "second direction" indicated by the middle arrow.

[0053] It should be noted that after the electrode coating process, the inspection process usually only checks the width of one layer of film area. By setting L1 > L2 and the difference between L1 and L2 within the range of 0.5 to 3, the width of the second film area can be determined by checking whether the width of the first film area is qualified during the post-processing inspection. This facilitates the inspection and ensures the accuracy of the inspection results.

[0054] In one embodiment, further combination Figures 4 to 9 As shown, the first gasket 1 includes a first connecting portion 110 and at least two first extension portions 120. The first extension portion 120 extends from a portion of the side of the first connecting portion 110 toward the discharge end 310, and a first discharge port 101 is formed between two adjacent first extension portions 120; further combined with Figures 10 to 15As shown, the second gasket 2 includes a second connecting portion 210 and at least two second extension portions 220. The second extension portions 220 extend from a portion of the side of the second connecting portion 210 toward the discharge end 310, and a second discharge port 201 is formed between two adjacent second extension portions 220. It should be noted that both the first connecting portion 110 and the second connecting portion 210 extend along a second direction. The first extension portion 120 extends from a portion of the side of the first connecting portion 110 toward the discharge end 310, and the second extension portion 220 extends from a portion of the side of the second connecting portion 210 toward the discharge end 310.

[0055] By setting the first gasket 1 to consist of a first connecting portion 110 and at least two first extension portions 120 connected to the first connecting portion 110, and forming a first discharge port 101 between two adjacent first extension portions 120, the first gasket 1 has at least one first discharge port 101, which facilitates the discharge of slurry between the first die head 301 and the second die head 302 from the first discharge port 101, thereby achieving slurry coating; by setting the second gasket 2 to consist of a second connecting portion 210 and at least two second extension portions 220 connected to the second connecting portion 210, and forming a second discharge port 201 between two adjacent second extension portions 220, which facilitates the discharge of slurry between the second die head 302 and the third die head 303 from the second discharge port 201, thereby achieving slurry coating.

[0056] In one embodiment, the first connecting portion 110 of the first gasket 1 is connected to three first extension portions 120, forming two first discharge ports 101, and the second connecting portion 210 of the second gasket 2 is connected to three second extension portions 220, forming two second discharge ports 201. The two second discharge ports 201 correspond one-to-one with the two first discharge ports 101, thereby enabling the coating of two coating belts at one time, which is beneficial to improving processing efficiency.

[0057] In other embodiments, the first connecting portion 110 may also be connected to two first extensions 120 to form a first discharge port 101, and the second connecting portion 210 may be connected to two second extensions 220 to form a second discharge port 201, thus achieving coating of one coating belt at a time. It is understood that, as an alternative implementation, the first connecting portion 110 may also be connected to four or more first extensions 120, and the second connecting portion 210 may be connected to four or more second extensions 220, thereby forming three or more first discharge ports 101 and second discharge ports 201, which can further improve processing efficiency.

[0058] In one embodiment, the end of the first extension 120 away from the first connecting portion 110 is provided with a first chamfer 130 and a wing 140. The first chamfer 130 is located at the corner of the first extension 120 facing the first discharge port 101, and is formed by a portion of the upper surface of the first extension 120 being recessed downwards. The wing 140 is connected to the side of the first extension 120 facing the first discharge port 101, and the end of the wing 140 away from the first connecting portion 110 is flush with the end of the first extension 120 away from the first connecting portion 110. The thickness of the first chamfer 130 is H12 mm, and the thickness of the wing 140 is H11 mm, where H11 < H12 < H1. The thickness refers to the dimension along the thickness direction of the first gasket 1, which is the direction perpendicular to its large surface.

[0059] It should be noted that the wing 140 extends the first extension 120 along the second direction, and the wing 140 occupies a certain dimension along the thickness direction of the first gasket 1. Therefore, the wing 140 occupies a certain space in the slurry along the thickness direction, allowing the slurry discharged from the first outlet 101 to be thinned after passing through the wing 140. The first chamfer 130 provides a guiding effect for the slurry, thereby reducing the slurry outflow velocity. The first film layer formed by the first slurry discharged from the first outlet 101 has the following thicknesses: for positions at the first outlet 101 without the wing 140 and the first chamfer 130, the corresponding thickness of the first film layer is equal to the thickness of the first gasket 1; for positions with the wing 140, the corresponding thickness of the first film layer is equal to the thickness of the first gasket 1 minus the thickness of the wing 140; for positions with the first chamfer 130, the corresponding thickness of the first film layer is equal to the thickness of the first gasket 1 minus the thickness of the first chamfer 130. Therefore, the total thickness H1 of the first gasket 1 is... When the thickness of the wing 140 (H11 mm) and the thickness of the first chamfer 130 (H12 mm) satisfy the relationship H11 < H12 < H1, the thickness of the wing 140 (H11 mm) and the thickness of the first chamfer 130 (H12 mm) can be such that the thickness of the wing 140 (H11 mm) and the thickness of the first chamfer 130 (H12 mm) on the first film layer, the thickness of the wing 140 (H12 mm) and the thickness of the first chamfer 130 (H12 mm) on the first film layer can be such that the thickness of the wing 140 (H11 mm) and the thickness of the first chamfer 130 (H12 mm) on the first film layer decreases sequentially.

[0060] That is, by constructing a first chamfer 130 and a wing 140 on the end of the first extension 120 away from the first connecting portion 110, and the first chamfer 130 and the wing 140 are both at the corner of the first extension 120 facing the first outlet 101, and the total thickness H1 mm of the first gasket 1, the thickness H11 mm of the wing 140, and the thickness H12 mm of the first chamfer 130 satisfy the relationship H11 < H12 < H1. The wing 140 thins the thickness of the first slurry flowing out of the first outlet 101, and the first chamfer 130 guides and further thins the thickness of the first slurry, thereby reducing the amount of slurry at the edge along the second direction, reducing the edge thickness of the first film layer formed by the first slurry, so that a thinning zone is formed at the edge position of the first film layer along the second direction, effectively avoiding the phenomenon of bulging and cracking of the electrode, improving the electrode yield and battery safety.

[0061] Specifically, for the first extension 120 located at the edge, one side of the first extension 120 along the second direction faces the first discharge port 101, and a first chamfer 130 and a flying wing 140 are provided at the corner of the first extension 120 on that side; for the first extension 120 located in the middle, a first chamfer 130 and a flying wing 140 are provided at the corners on both sides of the first extension 120 along the second direction.

[0062] In one embodiment, the maximum dimension of the first chamfered portion 130 along the extending direction of the first connecting portion 110 is A mm, and the maximum dimension of the first chamfered portion 130 along the extending direction of the first extending portion 120 is B mm. The extending direction of the first connecting portion 110 is perpendicular to the extending direction of the first extending portion 120. The value of A ranges from 0.5 to 5, and the value of B also ranges from 0.5 to 5. It should be noted that the extending direction of the first connecting portion 110 refers to... Figures 6 to 7 The "second direction" indicated by the middle arrow refers to the extension direction of the first extension 120. Figures 6 to 7The "third direction" indicated by the middle arrow is perpendicular to the second direction and forms an acute angle with the first direction. If A is less than 0.5, the dimension of the first chamfered portion 130 along the extension direction of the first connecting portion 110 is too small, resulting in an insufficiently wide thinning area on both sides of the first film layer formed by the first slurry along the second direction; if A is greater than 5, the dimension of the first chamfered portion 130 along the extension direction of the first connecting portion 110 is too large, resulting in an excessively wide thinning area of ​​the first film layer, wasting material; if B is less than 0.5, the dimension of the first chamfered portion 130 along the extension direction of the first extension portion 120 is too small, resulting in insufficient flow guiding effect of the first chamfered portion 130, which may cause the slurry to not flow smoothly to the outermost edge; if B is greater than 5, the dimension of the first chamfered portion 130 along the extension direction of the first extension portion 120 is too large, weakening the structural strength of the first chamfered portion 130.

[0063] Therefore, by setting the maximum dimension A of the first chamfered portion 130 along the extension direction of the first connecting portion 110 to be in the range of 0.5-5, and the maximum dimension B of the first chamfered portion 130 along the extension direction of the first extension portion 120 to be in the range of 0.5-5, the first chamfered portion 130 has a reasonable size. This ensures that the thinning area on both sides of the first film layer formed by the first slurry flowing out of the first outlet 101 along the second direction has a reasonable width, avoiding insufficient thinning area size or material waste. It also ensures the stability of the first slurry flowing through the first chamfered portion 130 and the structural strength of the first chamfered portion 130.

[0064] In one embodiment, the dimension of the flying wing 140 along the extension direction of the first connecting portion 110 is C mm, and the dimension of the flying wing 140 along the extension direction of the first extension portion 120 is D mm, wherein the value of C ranges from 1 to 10, and the value of D ranges from 3 to 50. The dimension C mm of the flying wing 140 along the extension direction of the first connecting portion 110 is the dimension of the flying wing 140 extending into the first discharge port 101 along the second direction, and the dimension D mm of the flying wing 140 along the extension direction of the first extension portion 120 is the dimension of the flying wing 140 along the third direction. If C is less than 1, the dimension of the flying wing 140 along the second direction is too small, and the width dimension along the second direction corresponding to the flying wing 140 on the thinning area of ​​the first film layer is too small, resulting in insufficient thinning area size. If C is greater than 10, the dimension of the flying wing 140 along the second direction is too large, and the width dimension along the second direction corresponding to the flying wing 140 on the thinning area is too large, resulting in insufficient material in the first film layer and low areal density. If D is less than 3, the dimension of the flying wing along the third direction is too small, and the thinning effect of the flying wing 140 on the first film layer is not obvious, and the phenomenon of the thinning area exceeding the thickness requirement is easy to occur. If D is greater than 50, the dimension of the flying wing 140 along the third direction is too large, and the structural stability is poor.

[0065] Therefore, by setting the dimension C of the flying wing 140 along the extension direction of the first connecting portion 110 to a value in the range of 1-10, and the dimension D of the flying wing 140 along the extension direction of the first extension portion 120 to a value in the range of 3-50, the flying wing 140 has a reasonable size. This ensures that the thinning area has a reasonable size along the second direction, avoiding insufficient size of the thinning area or insufficient surface density of the electrode sheet. It also ensures that the flying wing 140 can effectively thin the first film layer near the edge, ensuring the thinning effect and the structural strength of the flying wing 140 itself, thus improving reliability.

[0066] In one embodiment, the total thickness H1 mm of the first gasket 1, the thickness H12 mm of the first chamfer 130, and the thickness H11 mm of the flying wing 140 satisfy the following relationships: H12 / H1 = 2 / 3, H11 / H1 = 1 / 3. Further combining... Figure 5 and Figure 8 By setting the thickness of the three components to satisfy the relationship H12 / H1=2 / 3 and H11 / H1=1 / 3, the body of the first gasket 1, the first chamfer 130, and the flying wing 140 are arranged in a stepped shape with decreasing thickness, which facilitates the control of the dimensions of each part during the processing and helps to improve the processing accuracy and efficiency.

[0067] Specifically, the first chamfered portion 130 and the flying wing 140 are formed by milling. Taking the total thickness of the first gasket 1 as 0.6mm as an example, firstly, 1 / 3 (i.e. 0.2mm) of the total thickness of the first gasket 1 is milled off at the first chamfered portion 130 and the flying wing 140. Then, another 1 / 3 (i.e. 0.2mm) of the total thickness of the first gasket 1 is milled off on the flying wing 140, so that the thickness of the first chamfered portion 130 is 0.4mm and the thickness of the flying wing 140 is 0.2mm.

[0068] In one embodiment, a second chamfer 230 is formed at the end of the second extension 220 away from the second connecting portion 210. The second chamfer 230 is located at the corner of the second extension 220 on the side facing the second discharge port 201, and is formed by a portion of the upper surface of the second extension 220 being recessed downwards. The upper surface refers to the area along... Figure 1 and Figure 14 The surface in the direction indicated by the middle arrow ("up"); the downward indentation refers to the direction towards... Figure 14The indentation is in the direction indicated by the middle arrow "down". A second chamfered portion 230 is constructed at the corner of the second extension 220 facing the second outlet 201. The second chamfered portion 230 is formed by a portion of the upper surface of the second extension 220 being recessed downwards. Therefore, the thickness of the second chamfered portion 230 is less than the thickness of the second extension 220. The second chamfered portion 230 guides and thins the second slurry flowing from the second outlet 201, thereby reducing the amount of slurry at both edges along the second direction and reducing the edge thickness of the second film layer formed by the second slurry. This creates a thinning zone at both edges of the second film layer along the second direction, further preventing bulging and cracking of the electrode, improving electrode yield and battery safety. The thickness of the second chamfered portion 230 and the thickness of the second extension 220 refer to their respective thicknesses along the second direction. Figure 1 and Figure 14 The dimension in the "up and down" direction indicated by the middle arrow.

[0069] In one embodiment, the maximum dimension of the second chamfered portion 230 along the extending direction of the second connecting portion 210 is E mm, and the maximum dimension of the second chamfered portion 230 along the extending direction of the second extending portion 220 is F mm. The extending direction of the second connecting portion 210 is perpendicular to the extending direction of the second extending portion 220. The value of E ranges from 1 to 5, and the value of F ranges from 0.5 to 5. It should be noted that the extending direction of the second connecting portion 210 refers to... Figures 12 to 13 The "second direction" indicated by the middle arrow refers to the extension direction of the second extension 220. Figures 12 to 13 The "first direction" indicated by the middle arrow. If E is less than 1, the dimension of the second chamfer 230 along the extension direction of the second connecting portion 210 is too small, and the width of the thinning area formed on the second film layer under the action of the second chamfer 230 along the second direction is too small, resulting in insufficient thinning area size; if E is greater than 5, the dimension of the second chamfer 230 along the extension direction of the second connecting portion 210 is too large, resulting in an excessively large width of the thinning area of ​​the second film layer along the second direction, insufficient material on the second film layer, and low areal density; if F is less than 0.5, the dimension of the second chamfer 230 along the extension direction of the second extension portion 220 is too small, the guiding effect of the second chamfer 230 is insufficient, and the slurry may not flow smoothly to the outermost edge; if F is greater than 5, the dimension of the second chamfer 230 along the extension direction of the second extension portion 220 is too large, which weakens the structural strength of the second chamfer 230.

[0070] Therefore, by setting the maximum dimension E of the second chamfered portion 230 along the extension direction of the second connecting portion 210 to be in the range of 1-5, and the maximum dimension F of the second chamfered portion 230 along the extension direction of the second extension portion 220 to be in the range of 0.5-5, the second chamfered portion 230 has a reasonable size, ensuring that the thinning area on both sides of the second film layer formed by the second slurry flowing out of the second outlet 201 along the second direction has a reasonable width, avoiding insufficient electrode surface density, ensuring the thinning effect and that the second chamfered portion 230 has sufficient structural strength, and improving reliability.

[0071] In one embodiment, further combination Figure 11 and Figure 14 The thickness of the second chamfered portion 230 is H21 mm, and the relationship between H21 mm and the total thickness H2 mm of the second gasket 2 is H21 / H2 = 1 / 2. By setting the relationship between the thickness H21 mm of the second chamfered portion 230 and the total thickness H2 mm of the second gasket 2 to H21 / H2 = 1 / 2, the thickness of the second chamfered portion 230 is ensured to be less than the total thickness of the second gasket 2. The body of the second gasket 2 and the second chamfered portion 230 are stepped, which facilitates the control of the dimensions of the second chamfered portion 230 during processing and helps to improve processing accuracy and efficiency.

[0072] Specifically, the second chamfered portion 230 is formed by milling. During the milling process, half the thickness of the second gasket 2 is milled away from the position of the second chamfered portion 230 on the second extension portion 220.

[0073] In one embodiment, the maximum dimension E mm of the second chamfered portion 230 along the extension direction of the second connecting portion 210 and the maximum dimension A mm of the first chamfered portion 130 along the extension direction of the first connecting portion 110 satisfy the relationship: E > A. It should be noted that the width of the second film layer formed on the foil by the second slurry guided by the second gasket 2 is equal to L2 mm, and the width of the first film layer formed on the second film layer by the first slurry guided by the first gasket 1 is equal to L1 mm. There is a width difference between the first film layer and the second film layer. The area where the first film layer covers the second film layer and extends outwards along the second direction is such that if E is not greater than A, the overall width dimension of the thinned area formed by the first film layer and the second film layer along the second direction is too large, the overlap area of ​​the first film layer and the second film layer in the edge thinning area is too thick, and the electrode exceeds the thickness requirement. Therefore, by setting the maximum dimension E of the second chamfered portion 230 along the extension direction of the second connecting portion 210 to be greater than the maximum dimension A of the first chamfered portion 130 along the extension direction of the first connecting portion 110, it is possible to avoid the width or thickness of the thinning area at the edge of the overall film region along the second direction being too large, and to avoid the thinning area being too wide or the electrode exceeding the thickness requirement.

[0074] It should be noted that, based on actual production verification, E > A is the key to achieving an overall film area thinning width ≤ 8mm and a single-sided thinning thickness ≤ 10mm.

[0075] Further integration Figure 9 As shown, the width of the first film layer formed by the first slurry extruded between the first die head 301 and the second die head 302 is equal to the opening width L1 of the first discharge port 101, wherein the opening width of the first discharge port 101 refers to the width of the film layer formed by the first slurry extruded between the first die head 301 and the second die head 302. Figure 9 In the "second direction" indicated by the middle arrow, the distance between the corner points of the first chamfered portions 130 on the first extensions 120 on both sides of the first discharge port 101, where they are far apart; further combined with Figure 15 As shown, the width of the second film layer formed by the second slurry extruded between the second die head 302 and the third die head 303 is equal to the opening width L2 of the second discharge port 201. The opening width of the second discharge port 201 refers to the width of the film layer formed by the second slurry extruded between the second die head 302 and the third die head 303. Figure 15 The distance between the corner points of the second chamfered portions 230 on the second extensions 220 on both sides of the second discharge port 201 in the "second direction" indicated by the middle arrow.

[0076] In this embodiment, the coating die head is equipped with two gaskets, and the two gaskets are designed with different opening widths, different thicknesses and different chamfer structures to achieve simultaneous coating of two different materials in the upper and lower layers, thereby realizing the double-layer coating of the electrode.

[0077] According to an embodiment of the present invention, in another aspect, a coating apparatus is also provided, including the aforementioned coating die head. The coating apparatus further includes an apparatus body, on which the coating die head is mounted for coating the electrode sheet.

[0078] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A coating die head, characterized in that, include: The die head assembly (3) includes a first die head (301), a second die head (302) and a third die head (303) stacked in sequence. In the stacking direction perpendicular to the first die head (301), the second die head (302) and the third die head (303), one end of the die head assembly (3) forms a discharge end (310). The first gasket (1) is sandwiched between the first die head (301) and the second die head (302). The first gasket (1) has a first discharge port (101) opening towards the discharge end (310). The total thickness of the first gasket (1) is H1mm, and the opening width of the first discharge port (101) is L1mm. The second gasket (2) is sandwiched between the second die head (302) and the third die head (303). The second gasket (2) has a second discharge port (201) opening towards the discharge end (310). The total thickness of the second gasket (2) is H2mm, and the opening width of the second discharge port (201) is L2mm. Among them, H1 and H2 satisfy the condition: H1 > H2, and L1 and L2 satisfy the condition: L1 > L2.

2. The coating die head according to claim 1, characterized in that, The opening width L1 mm of the first discharge port (101) and the opening width L2 mm of the second discharge port (201) satisfy the following relationship: 0.5 ≤ L1 - L2 ≤ 3.

3. The coating die head according to claim 1, characterized in that, The first gasket (1) includes a first connecting portion (110) and at least two first extension portions (120). The first extension portion (120) is formed by a portion of the side of the first connecting portion (110) extending toward the discharge end (310). The first discharge port (101) is formed between two adjacent first extension portions (120). The second gasket (2) includes a second connecting portion (210) and at least two second extension portions (220). The second extension portion (220) extends from a portion of the side of the second connecting portion (210) toward the discharge end (310), and a second discharge port (201) is formed between two adjacent second extension portions (220).

4. The coating die head according to claim 3, characterized in that, The first extension (120) has a first chamfer (130) and a wing (140) at one end away from the first connecting part (110). The first chamfer (130) is located at the corner of the first extension (120) facing the first discharge port (101). The first chamfer (130) is formed by a portion of the upper surface of the first extension (120) being recessed downwards. The wing (140) is connected to the side of the first extension (120) facing the first discharge port (101). The end of the wing (140) away from the first connecting part (110) is flush with the end of the first extension (120) away from the first connecting part (110). The thickness of the first chamfer (130) is H12 mm, and the thickness of the wing (140) is H11 mm, wherein H11 < H12 < H1.

5. The coating die head according to claim 4, characterized in that, The maximum dimension of the first chamfered portion (130) along the extension direction of the first connecting portion (110) is A mm, and the maximum dimension of the first chamfered portion (130) along the extension direction of the first extension portion (120) is B mm. The extension direction of the first connecting portion (110) is perpendicular to the extension direction of the first extension portion (120). The value range of A is 0.5-5, and the value range of B is 0.5-5.

6. The coating die head according to claim 4, characterized in that, The dimension of the flying wing (140) along the extension direction of the first connecting part (110) is C mm, and the dimension of the flying wing (140) along the extension direction of the first extension part (120) is D mm, wherein the value of C is in the range of 1-10, and the value of D is in the range of 3-50. And / or, the total thickness H1 mm of the first gasket (1), the thickness H12 mm of the first chamfer (130), and the thickness H11 mm of the flying wing (140) satisfy the following relationship: H12 / H1 = 2 / 3, H11 / H1 = 1 / 3.

7. The coating die head according to claim 5, characterized in that, The second extension (220) has a second chamfer (230) at one end away from the second connecting part (210). The second chamfer (230) is located at the corner of the second extension (220) on the side facing the second discharge port (201). The second chamfer (230) is formed by a portion of the upper surface of the second extension (220) being recessed downward.

8. The coating die head according to claim 7, characterized in that, The maximum dimension of the second chamfered portion (230) along the extension direction of the second connecting portion (210) is E mm, and the maximum dimension of the second chamfered portion (230) along the extension direction of the second extension portion (220) is F mm. The extension direction of the second connecting portion (210) is perpendicular to the extension direction of the second extension portion (220). The value range of E is 1-5, and the value range of F is 0.5-5. And / or, the thickness of the second chamfer (230) is H21 mm, wherein H21 mm and the total thickness H2 mm of the second gasket (2) satisfy the relationship: H21 / H2=1 / 2.

9. The coating die head according to claim 8, characterized in that, The maximum dimension E mm of the second chamfered portion (230) along the extension direction of the second connecting portion (210) and the maximum dimension A mm of the first chamfered portion (130) along the extension direction of the first connecting portion (110) satisfy the relationship: E > A.

10. A coating apparatus, characterized in that, include: The coating die head according to any one of claims 1 to 9.

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