Extrusion coating composite gasket structure and extrusion coating machine

Abstract

The invention discloses an extrusion coating composite gasket structure and an extrusion coating machine, and relates to the technical field of pole piece coating, the extrusion coating composite gasket structure comprises a main gasket and a forced cutting gasket, the main gasket comprises a transverse piece and two extension side pieces connected to the two sides of the transverse piece, and the transverse piece and the two extension side pieces define a hollow main slurry channel; a main slurry outlet is formed in the main slurry channel in the material coating direction; the forced cutting gasket comprises a connecting head part, a forced cutting part and a flow blocking part connected between the connecting head part and the forced cutting part, the connecting head part is arranged in the middle of the transverse piece, the flow blocking part is located in the main slurry channel, and the forced cutting part is located at the main slurry outlet; the thickness of the forced cutting part is smaller than that of the connecting head part and the flow blocking part; through the composite structure of the main body gasket and the forced cutting gasket, the amount of slurry in the middle during positive electrode coating is reduced, and the problem of lithium precipitation during positive electrode coating is solved; the forced cutting gasket can move back and forth within a certain range, and adjustment of the cutting width and thickness in a main slurry channel and an outlet is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of pole piece coating, and in particular to an extrusion coating composite gasket structure and an extrusion coating machine. Background Art

[0002] With the support of national electrification policies, the market share of power batteries has been rising year by year. Double-ended tab stacked batteries are increasingly favored by OEM customers due to their high energy density, good heat dissipation and strong versatility. The structure of double-ended tab battery cells is shown in the following figure. Figure 1 shown.

[0003] According to the length of the battery cell, the current industrial battery electrode coating production method often adopts a one-out-two / four-out / multi-way method. When stacking, the head of the negative electrode corresponds to the tail of the positive electrode. At this time, due to the thinning area at the electrode head, the NP ratio of the negative electrode thinning area (the ratio of the battery negative electrode capacity to the motor capacity) will be insufficient. Figure 2 As shown, the coating die head at the positive electrode is prone to lithium precipitation in the later stage of the battery cell, resulting in failure of battery cell performance and even safety problems. Therefore, the coating die head of the positive electrode needs to be thinned.

[0004] Usually, the coating die head of the coating machine is composed of three parts: the lower die, the die head gasket and the upper die. There is a technology that can achieve middle thinning by adding branches to the gasket, such as a gasket and coating device for adjusting the thickness of the middle area of ​​the coated electrode disclosed in patent CN215542359U. This structure has limited thinning effect and cannot be adjusted according to the thinning requirements of different products. It is difficult to achieve an ideal balance effect of thinning treatment of positive and negative electrode coating slurries. Summary of the invention

[0005] In view of one or more deficiencies in the above-mentioned prior art, the present invention provides an extrusion coated composite gasket structure and an extrusion coating machine, which are mainly suitable for the positive electrode die head, and can achieve effective thinning of the middle part of the die head. At the same time, the thinning width and thickness can be adjusted according to product requirements, which can not only avoid the problem of lithium plating of the gasket, but also facilitate employee operation and control.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] An extrusion-coated composite gasket structure comprises a main gasket and a strong-cutting gasket, wherein the main gasket is an integrated structure, comprising a transverse piece and two extended side pieces connected to both sides of the transverse piece, wherein the transverse piece and the two extended side pieces are arranged to form a hollow main slurry channel, and the main slurry channel is provided with a main slurry outlet in the direction of material coating;

[0008] The strong cutting gasket is an integrated structure, including a connecting head, a strong cutting portion and a flow blocking portion connected between the connecting head and the strong cutting portion, the connecting head is arranged in the middle position of the cross piece, the flow blocking portion is located in the main slurry channel, and the strong cutting portion is located at the main slurry outlet; the thickness of the strong cutting portion is less than the thickness of the connecting head and the flow blocking portion.

[0009] As a further implementation method, the main body gasket is provided with a plurality of gasket positioning holes for connecting with the die head.

[0010] As a further implementation method, a strong cutting positioning hole is opened on the connecting head, and the strong cutting positioning hole is an elliptical hole. The focus of the ellipse is arranged perpendicular to the horizontal direction. The strong cutting gasket is installed on the die head through the strong cutting positioning hole. At the same time, the installation position of the strong cutting gasket can be moved forward and backward to adjust the thickness and width of the thinning area, which can effectively meet the thinning requirements of the product.

[0011] As a further implementation, the thickness H3 of the connecting head and the baffle is 0.5-3.0 mm, which is the same as the thickness of the main gasket, so as to match the main gasket and facilitate installation operation and die head closure.

[0012] As a further implementation method, the thickness D1 of the strong cutting portion is 5%-95% of the thickness H3, which can reduce the slurry flow rate of the strong cutting portion and achieve thinning in the middle of the pole piece.

[0013] As a further implementation, the end of the strong cutting portion is set to be rectangular, the length H2 of the strong cutting portion parallel to the cross piece is 2-50 mm, and the width H1 of the strong cutting portion perpendicular to the cross piece is 5-25 mm.

[0014] As a further implementation, the distance H0 from the strong chipping portion extending into the main slurry channel and connecting with the baffle portion is 0-30 mm, so as to control the advance amount of the slurry entering the chipping area, thereby controlling the chipping intensity.

[0015] As a further implementation method, the main body gasket and the strong cutting gasket are both made of high-strength stainless steel.

[0016] As a further implementation method, the two extended side pieces are chamfered at opposite ends on both sides of the main slurry outlet, so as to control the thinning width and thickness according to the thinning requirements of different products.

[0017] As a further implementation method, the distance between the outer end of the connecting head and the inner wall of the cross piece is 0-2 mm. By adjusting the position of the strong cutting gasket within this range, the best slurry reduction effect of the pole piece can be ensured.

[0018] On the other hand, the present invention further provides an extrusion coating machine, which includes a coating die, wherein the coating die includes an upper die, a lower die and a die gasket, and the die gasket adopts any of the extrusion coating composite gasket structures described above.

[0019] By adopting the above technical solution, the beneficial effects of the present invention are as follows:

[0020] 1. The present invention arranges a strong cutting gasket in the middle of the main gasket to form a composite gasket structure, which can not only use the strong cutting gasket to realize slurry diversion and slow down the slurry flow rate, but also reduce the amount of slurry in the middle during positive electrode coating, which can effectively avoid the lithium plating problem of positive electrode coating; moreover, the strong cutting gasket can move back and forth within a certain range relative to the main gasket, thereby adjusting the distance between the strong cutting gasket and the back roller of the material coating area, realizing the adjustment of the thinning width and thickness in the main slurry channel and the outlet, and improving the controllability of the thinning effect.

[0021] 2. The utility model can also be applied to the negative electrode coating die head, which can reduce material loss and improve energy density. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0023] Figure 1 A schematic plan view of an embodiment of the present invention;

[0024] Figure 2 A schematic plan view of a strong cutting gasket according to an embodiment of the present invention;

[0025] Figure 3 It is a schematic diagram of the size design of the strong cutting portion of the strong cutting gasket according to an embodiment of the present invention.

[0026] In the figure: 1, main gasket; 11, transverse piece; 12, extended side piece; 13, main slurry channel; 14, main slurry outlet; 15, gasket positioning hole;

[0027] 2. Strong cutting gasket; 21. Connecting head; 22. Flow blocking part; 23. Strong cutting part; 24. Strong cutting positioning hole. DETAILED DESCRIPTION

[0028] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0029] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0030] Embodiment 1

[0031] In a typical embodiment of the present application, an extrusion-coated composite gasket structure is provided, such as Figure 1-3 As shown, it includes a main gasket 1 and a strong cutting gasket 2. The main gasket 1 is an integrated structure, including a transverse piece 11 and two extended side pieces 12 connected on both sides of the transverse piece. The transverse piece 11 and the two extended side pieces 12 are surrounded to form a hollow main slurry channel 13. The main slurry channel 13 is provided with a main slurry outlet 14 toward the direction of material coating;

[0032] The strong cutting gasket 2 is an integrated structure, including a connecting head 21, a strong cutting portion 23 and a baffle 22 connected between the connecting head and the strong cutting portion. The connecting head 21 is arranged in the middle position of the cross piece 11, the baffle 22 is located in the main slurry channel 13, and the strong cutting portion 23 is located at the main slurry outlet 14; the thickness of the strong cutting portion 23 is less than the thickness of the connecting head 21 and the baffle 22.

[0033] In this embodiment, outside the main slurry outlet is a back roller for slurry coating, the strong cutting gasket is arranged between the main gaskets, the flow blocking part diverts the slurry in the main slurry channel, and the strong cutting part is in the middle of the main slurry outlet so that most of the slurry flows out from both sides, and a small part of the slurry flows out along the strong cutting part, thereby thinning the coating in the middle of the pole piece.

[0034] Specifically, in order to realize the connection and fixation between the composite gasket structure and the die head, a gasket positioning hole is opened on the main gasket 1, such as Figure 1 As shown, the main gasket 1 is provided with a plurality of evenly distributed gasket positioning holes 15, the size and hole spacing of which can be determined according to the requirements of different die heads, and during installation, the die head and the gasket positioning holes are fixedly connected by die head fixing nuts.

[0035] Specifically, the strong cutting gasket 2 is arranged in the middle position of the main gasket 1 to ensure that the middle part of the electrode coating is cut. In order to realize the installation of the strong cutting gasket, a strong cutting positioning hole is opened on the connecting head of the strong cutting gasket, such as Figure 1 , 2As shown, two strong cutting positioning holes 24 are provided on the connecting head 21, and the strong cutting gasket 2 is installed on the die head through the strong cutting positioning holes 24. In order to achieve the adjustable thinning effect, in this embodiment, as shown in FIG. Figure 1 , 2 As shown, the strong cutting positioning hole 24 is set as an elliptical hole, and the focus of the ellipse is arranged perpendicular to the horizontal direction. This allows the strong cutting gasket to be fine-tuned forward and backward along the direction perpendicular to the horizontal direction when installed on the die head, thereby changing the distance from the back roller of the material coating area; when the distance is far, the slurry coated on the foil per unit time increases, and the overflow angle becomes larger; when the distance is close, the slurry coated on the foil per unit time decreases, and the overflow angle becomes smaller, thereby achieving adjustment of the thickness and width of the thinning area. When applied, specific adjustments can be made according to the thinning requirements of the product to better achieve the ideal thinning effect.

[0036] Specifically, in order to meet the thinning requirements, the thickness of the strong chipping gasket varies in different parts, such as Figure 2 As shown, the thickness H3 of the connecting head 21 and the baffle 22 is 0.5-3.0 mm, which is the same as the thickness of the main gasket 1. In this way, the thickness H3 of the main gasket can be determined according to the coating thickness of different products, so that the thickness of the strong cutting gasket is consistent with the thickness of the main gasket, which is convenient for matching and installing with the main gasket, and does not affect the circulation direction of the slurry fluid inside the die head. The thickness D1 of the strong cutting portion 23 is 5%-95% of the thickness H3, which can reduce the slurry flow of the strong cutting portion and realize the thinning in the middle of the pole piece.

[0037] In this embodiment, Figure 2 , 3 As shown, the end of the strong cutting part 23 is set to be rectangular, the length H2 of the strong cutting part parallel to the cross piece is 2-50mm, and the width H1 perpendicular to the cross piece is 5-25mm. The distance H0 from the strong cutting part 23 extending to the main slurry channel and connecting with the baffle part is 0-30mm, the purpose is to control the flow rate of slurry flowing into the thinning area and thus control the thinning effect. Figure 3 As shown, the width H1 and the distance H0 can be combined in many different ways. Within a certain range of the baffle, the larger H0 is, the more obvious the thinning effect on the middle of the slurry is. When H1 is smaller, the thinning ability of the slurry flow is weaker. Therefore, different specifications of strong thinning gaskets can be selected according to the actual coating, so as to achieve precise flow control, meet the thinning requirements of different products, and achieve an ideal balance effect when coating and thinning the positive and negative electrode coating slurries.

[0038] In addition, if Figure 1As shown, the outer end of the connecting head 21 can protrude a certain distance from the inner wall of the cross piece 11, further reducing the area of ​​the main slurry channel and shortening the distance between the strong cutting area and the back roller, so as to more effectively reduce the slurry in the middle. In this embodiment, the distance between the outer end of the connecting head 21 and the inner wall of the cross piece 11 is 0-2mm. By adjusting the position of the strong cutting gasket within this range, the best slurry reduction effect of the pole piece can be achieved.

[0039] In this embodiment, the gasket body and the strong cutting gasket are both made of high-strength stainless steel.

[0040] In this embodiment, the two extended side pieces 12 are chamfered at opposite ends on both sides of the main slurry outlet 14 to control the width and thickness of the thinning area.

[0041] This embodiment can be applied to the positive electrode coating die head to solve the performance failure and safety problems caused by lithium deposition at the negative electrode head corresponding to the positive electrode tail in the double-headed output ear structure battery cell; at the same time, this embodiment adopts a composite structure of a main gasket + a strong cutting gasket in the middle, and the strong cutting gasket can move forward and backward, which can meet the thickness and width requirements of different products for the thinning area, and can not only solve the performance failure and safety problems caused by lithium deposition at the negative electrode head corresponding to the positive electrode tail, but also meet the convenience of employees in installation and operation, which is economical and practical. In addition, in addition to being used for the positive electrode to solve the lithium deposition problem, this embodiment can also be applied to the negative electrode die head to save the slurry loss in the thinning area, improve the battery energy density, save part of the material cost, and improve the company's benefits.

[0042] Example 2

[0043] In another typical embodiment of the present invention, an extrusion coating machine is provided, which includes a coating die, wherein the coating die includes an upper die, a lower die and a die gasket, and the die gasket adopts the extrusion coating composite gasket structure in Example 1.

[0044] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Those skilled in the art should understand that the present invention may have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. An extrusion coated composite gasket structure, characterized in that: It includes a main gasket and a strong cutting gasket. The main gasket is an integrated structure, including a transverse piece and two extended side pieces connected on both sides of the transverse piece. The transverse piece and the two extended side pieces are surrounded to form a hollow main slurry channel. The main slurry channel is provided with a main slurry outlet toward the direction of material coating. The strong cutting gasket is an integrated structure, including a connecting head, a strong cutting portion and a flow blocking portion connected between the connecting head and the strong cutting portion, the connecting head is arranged in the middle position of the cross piece, the flow blocking portion is located in the main slurry channel, and the strong cutting portion is located at the main slurry outlet; the thickness of the strong cutting portion is less than the thickness of the connecting head and the flow blocking portion.

2. An extrusion coated composite gasket structure as claimed in claim 1, characterized in that: The main body gasket is provided with a plurality of gasket positioning holes for connecting with the die head.

3. An extrusion coated composite gasket structure as claimed in claim 1, characterized in that: The connecting head is provided with a strong cutting positioning hole, which is an elliptical hole, the focus of the ellipse is arranged perpendicular to the horizontal direction, and the strong cutting gasket is installed on the die head through the strong cutting positioning hole.

4. An extrusion coated composite gasket structure as claimed in claim 1, characterized in that: The thickness H3 of the connecting head and the baffle is 0.5-3.0 mm, which is the same as the thickness of the main body gasket.

5. An extrusion coated composite gasket structure as claimed in claim 4, characterized in that: The thickness D1 of the strongly cut portion is 5% to 95% of the thickness H3.

6. An extrusion coated composite gasket structure as claimed in claim 1, characterized in that: The end of the strong cutting portion is set to be rectangular, the length H2 of the strong cutting portion parallel to the transverse piece is 2-50mm, and the width H1 of the strong cutting portion perpendicular to the transverse piece is 5-25mm.

7. An extrusion coated composite gasket structure as claimed in claim 6, characterized in that The distance H0 from the strong cutting portion extending into the main slurry channel and connecting with the baffle portion is 0-30 mm; the distance between the outer end of the connecting head and the inner wall of the transverse sheet is 0-2 mm.

8. An extrusion coated composite gasket structure as claimed in claim 1, characterized in that: The main body gasket and the strong cutting gasket are both made of stainless steel.

9. An extrusion coated composite gasket structure as claimed in claim 1, characterized in that: The two extended side pieces are respectively processed with chamfers at opposite ends on both sides of the main slurry outlet.

10. An extrusion coating machine, comprising a coating die, wherein the coating die comprises an upper die, a lower die and a die gasket, wherein: The die head gasket adopts an extrusion coated composite gasket structure as described in any one of claims 1-9.

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