Coating feed gap valve for lithium battery pole pieces

Abstract

This utility model relates to a coating and feeding gap valve for lithium battery electrodes, comprising a first valve body and a second valve body connected via a connecting pipe. A valve stem and a valve cover plate are respectively built into the cylinder of the first and second valve bodies. A sealing ring assembly is connected to the middle of the valve stem, and a connecting pin hole is provided at its lower end. The valve stem is connected to a drive mechanism via an inserted connecting pin in the connecting pin hole. The valve cover plate and valve stem form an integral valve stem structure, and the valve cover plate of the integral valve stem is fitted with a PTFE gasket fixed to the upper opening of the cylinder. This utility model improves the coating and feeding gap valve by addressing the structural problems of the valve stem by making the valve stem and valve cover plate an integral structure. While ensuring operational stability, it improves the valve closing speed and prevents leakage caused by valve stem and cover plate leaks, as well as problems such as material leakage at intervals and large differences in thickness between the beginning and end of the valve.

Description

Technical Field

[0001] This invention relates to a coating and feeding gap valve for lithium battery electrodes. Background Technology

[0002] In the lithium-ion battery production process, the coating process is the most crucial step in determining the safety of the battery electrode. The stable operation of the gap valve is a prerequisite for ensuring the appearance and dimensions of the electrode, and the design of the valve stem and cover directly affects the thickness and size of the coated electrode. The existing structure involves a central opening in the gap valve through which the valve stem passes, and then the valve cover is secured to the upper thread of the valve stem with a nut to assemble the valve stem and cover. Because there is a gap between the valve stem and the valve cover, the gap valve may not close tightly when closed, leading to material leakage. Especially during the opening and closing process, the valve stem moves up and down. Since the valve stem and valve cover are connected by threads, friction occurs on the threads of the valve stem, causing the valve cover to lag and jam when it falls, resulting in poor coating thickness and surface condition at both ends of the electrode. Patent document CN 222887244 U discloses a gap valve sealing structure for a lithium battery coating machine, including a gap valve placed inside the coating cylinder. The gap valve comprises a V-shaped gasket assembly, a rubber gasket, a gap valve connecting rod, and a connecting rod locking sleeve. The V-shaped gasket assembly is fitted onto the gap valve connecting rod and tightened therewith by the connecting rod locking sleeve. The top of the V-shaped gasket has a rubber gasket, and the upper part of the rubber gasket is connected to the gap valve cylinder to form an integral gap valve sealing structure. This improvement solves the problem of material leakage during gap valve sealing. In the continuous and intermittent coating processes of battery electrode foil, the gap valve is a prerequisite for ensuring the surface condition of the coating. Currently, using a motor to drive and control the gap valve allows for quantitative adjustment of the valve's opening and closing stroke and speed. However, high-speed coating, with the slurry being rapidly squeezed and conveyed (specifically, squeezed by a motor-driven valve stem and conveyed to the die head of the battery electrode coating equipment), intensifies the coating pressure at the initial coating moment. Due to the aforementioned valve stem structural issues, the battery electrodes obtained through intermittent coating exhibit an excessively thick slurry at the initial position (i.e., the starting position), thus posing a risk of lithium plating. Within a 5mm width following the initial position, the electrode thickness is generally 10-20μm greater than the normal position. The areal density of the active material at this location exceeds the design value, creating a risk of lithium plating at the positive electrode's initial position and easily forming a crushing dead zone on the negative electrode, thereby affecting battery safety and performance, posing a significant safety risk.

[0003] Therefore, there is an urgent need to improve the gap valve of the existing technology to solve the problem of excessive slurry coating thickness at the first position of the electrode, so as to effectively ensure the safety and performance of the final battery under high-speed gap coating mode. Utility Model Content

[0004] The present invention aims to overcome the shortcomings of the prior art by providing a coating and feeding gap valve for lithium battery electrodes, thereby improving the valve's closing speed and reducing problems such as material leakage and large thickness differences between the beginning and end of the valve due to incomplete closure.

[0005] To achieve the above objectives, this utility model provides a coating and feeding gap valve for lithium battery electrodes, comprising a first valve body and a second valve body connected via a valve body connecting pipe. A valve stem and a valve cover plate are respectively built into the cylinder of the first valve body and the cylinder of the second valve body. A sealing ring assembly is connected to the middle of the valve stem, and a connecting pin hole is provided at its lower end. The valve stem is connected to a drive mechanism via an inserted connecting pin in the connecting pin hole. The valve cover plate and the valve stem form an integral valve stem structure, and the integral valve stem is fitted to the upper opening of a PTFE gasket fixed on the cylinder body.

[0006] Furthermore, the integrated valve stem includes a truncated cone and a cylindrical rod, which are fixedly connected to form an integral structure. The cylindrical rod constitutes the valve stem of the clearance valve, and the truncated cone constitutes the valve cover plate of the clearance valve. The cylindrical rod passes through the central hole of the PTFE gasket, and the conical surface of the truncated cone is sealed and fitted with the upper circumferential surface of the PTFE gasket. The lower end of the integrated valve stem is provided with a pin hole and is pinned to the drive mechanism. The integrated valve stem moves up and down through the drive mechanism.

[0007] Furthermore, the diameter of the cylindrical stem of the integrated valve stem is smaller than the diameter of the central hole of the PTFE gasket.

[0008] Furthermore, the truncated cone of the integrated valve stem has a circular edge with a diameter greater than the bottom circle diameter of the truncated cone, and the height of the circular edge is 1-2mm.

[0009] Furthermore, the maximum opening and closing distance between the truncated cone of the integrated valve stem and the upper opening of the PTFE gasket is 3mm-5mm.

[0010] Furthermore, the conical surface of the truncated cone of the integrated valve stem matches the chamfer at the top of the PTFE gasket.

[0011] Furthermore, the integrated valve stem is made of 304 stainless steel.

[0012] Beneficial effects: Compared with existing technologies, this utility model improves the coating and feeding gap valve by addressing the structural problems of the valve stem, making the valve stem and valve cover plate into an integrated structure. While ensuring operational stability, it increases the valve's closing speed and prevents leakage caused by incomplete valve stem and cover plate sealing. Installation is simple and requires no adjustment. More importantly, it reduces problems such as material leakage and large thickness differences between the beginning and end of the valve due to incomplete sealing, and also extends the service life of the gap valve consumables. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the integral valve stem of this utility model;

[0014] Figure 2 This is a schematic diagram of the improved coating and feeding gap valve with an integrated valve stem in the open state.

[0015] Figure 3 This is a schematic diagram of the closed state of the integrated valve stem of the improved coating and feeding gap valve;

[0016] Figure 4 This is a schematic diagram of the coating and feeding gap valve structure before the improvement;

[0017] Figure 5 This is a schematic diagram of the improved clearance valve's stem and cover plate separation structure.

[0018] In the diagram: 1. First valve body, 2. Second valve body, 3. Valve body connecting pipe, 4. Cylinder, 5. Sealing ring assembly, 6. Connecting pin hole, 7. Drive mechanism, 8. PTFE gasket, 9. Valve stem, 10. Valve cover plate, 11. Integrated valve stem, 11-1. Frustum conical body, 11-1-1. Circular edge, 11-2. Cylindrical rod body, 12. Nut.

[0019] H, the maximum opening and closing distance between the truncated cone and the upper opening of the PTFE gasket. Detailed Implementation

[0020] The following detailed description of the specific embodiments provided by this utility model, in conjunction with preferred embodiments, is provided in the appendix. Figure 1-4 This embodiment provides a coating and feeding gap valve for lithium battery electrodes, including a first valve body 1 and a second valve body 2 connected by a valve body connecting pipe 3. A valve stem 9 and a valve cover plate 10 are respectively built into the cylinder body 4 of the first valve body and the cylinder body of the second valve body. A sealing ring group 5 is fitted in the middle of the valve stem, and a connecting pin hole 6 is provided at its lower end. The valve stem is connected to the drive mechanism 7 through a connecting pin inserted into the connecting pin hole. The valve cover plate and the valve stem form an integral valve stem structure. The integral valve stem is connected to the upper opening of the PTFE gasket 8 fixed on the cylinder body.

[0021] In a preferred embodiment, the integrated valve stem includes a truncated cone body 11-1 and a cylindrical rod body 11-2. The truncated cone body and the cylindrical rod body are fixedly connected to form an integral structure. The cylindrical rod body constitutes the valve stem of the clearance valve, and the truncated cone body constitutes the valve cover plate of the clearance valve. The cylindrical rod body passes through the central hole of the PTFE gasket. The conical surface of the truncated cone body is sealed and fitted with the upper circumferential surface of the PTFE gasket. The lower end of the integrated valve stem is provided with a pin hole and is pinned to the drive mechanism. The integrated valve stem moves up and down through the drive mechanism.

[0022] In a preferred embodiment, the diameter of the cylindrical stem of the integrated valve stem is smaller than the diameter of the central hole of the PTFE gasket, and the space between them facilitates the flow of coating.

[0023] In a preferred embodiment, the truncated cone of the integrated valve stem has a circular rim 11-1-1 with a diameter greater than the base circle diameter of the truncated cone, and a height of 1-2 mm. This circular rim design better ensures its sealing function.

[0024] In this preferred embodiment, the maximum opening and closing distance between the truncated cone of the integrated valve stem and the upper opening of the PTFE gasket is 3mm-5mm. Based on practical experience, designing the maximum opening and closing degree of the integrated valve stem as a fixed value ensures a fast response speed when the integrated valve stem falls downwards, which can fully adapt to the valve closing speed controlled by pressure and the valve stem's own weight, thus ensuring that the coating thickness at the beginning and end of the electrode plate does not exceed the limit.

[0025] In a preferred embodiment, the conical surface of the truncated cone of the integrated valve stem matches the chamfer at the top of the PTFE gasket. This fit between the conical surface and the chamfer at the top of the PTFE gasket prevents material leakage.

[0026] In a preferred embodiment, the integrated valve stem is made of 304 stainless steel.

[0027] See appendix for details Figure 3 The overall structure of the coating and feeding gap valve includes a first valve body on the right side and a second valve body on the left side, connected by a hollow valve body connecting pipe. The internal space of the first valve body, the second valve body, and the valve body connecting pipe forms a valve body material chamber for the flow of slurry used to coat battery electrode foil. A slurry inlet is located on the left side of the first valve body, which is connected to an external slurry conveying device (e.g., a slurry conveying pump). The gap valve uses a drive mechanism that moves the valve cover plate via a valve stem to control the flow of slurry. The valve stem passes directly through the center point of the valve cover plate and is locked in place with a nut 12. The valve opening is adjusted by the length of the locking thread at the upper end of the valve stem, thereby controlling the flow rate. Since this invention improves upon existing coating and feeding gap valves, its specific structure will not be described in detail.

[0028] The key improvement of this utility model lies in the fact that stable operation of the gap valve is a prerequisite for ensuring the appearance and dimensions of the electrode sheet, and the structure of the valve stem and valve cover plate directly affects the thickness and dimensions of the coated electrode sheet. The original structure involved a hole in the center of the valve cover plate, through which the valve stem passed and was threaded to the upper end of the valve stem with a nut for locking. However, the gap between the valve stem and valve cover plate caused incomplete closure, leading to material leakage. Furthermore, the slow response of the valve cover plate during the opening / closing process of the gap valve, caused by the up-and-down movement of the valve stem, resulted in lag and jamming, causing problems such as poor thickness and surface condition at both ends of the electrode sheet. This utility model integrates the valve stem and valve cover plate into a single, unified structure, improving the valve's closing speed and reducing problems such as material leakage and large thickness differences between the beginning and end of the electrode sheet due to incomplete closure.

[0029] The above detailed description of a coating and feeding gap valve for lithium battery electrodes, with reference to the embodiments, is illustrative rather than limiting. Several embodiments can be listed according to the defined scope. Therefore, changes and modifications without departing from the overall concept of this utility model should be within the protection scope of this utility model.

Claims

1. A coating and feeding gap valve for lithium battery electrodes, comprising a first valve body and a second valve body connected via a valve body connecting pipe, wherein a valve stem and a valve cover plate are respectively built into the cylinder of the first valve body and the cylinder of the second valve body, a sealing ring assembly is connected to the middle of the valve stem, and a connecting pin hole is provided at its lower end, wherein the valve stem is connected to a drive mechanism through an inserted connecting pin in the connecting pin hole, characterized in that: The valve cover and valve stem are an integral valve stem structure, and the integral valve stem is connected to the upper opening of the PTFE gasket fixed on the cylinder body.

2. The coated web gap valve for lithium battery pole pieces of claim 1, wherein: The integrated valve stem includes a truncated cone and a cylindrical rod, which are fixedly connected to form an integral structure. The cylindrical rod constitutes the valve stem of the clearance valve, and the truncated cone constitutes the valve cover plate of the clearance valve. The cylindrical rod passes through the central hole of the PTFE gasket. The conical surface of the truncated cone is sealed and fitted with the upper circumferential surface of the PTFE gasket. The lower end of the integrated valve stem is provided with a pin hole and is pinned to the drive mechanism. The integrated valve stem moves up and down through the drive mechanism.

3. The coated web gap valve for lithium battery pole pieces of claim 1 or 2, characterized by: The diameter of the cylindrical stem of the integrated valve is smaller than the diameter of the center hole of the PTFE gasket.

4. The coated web gap valve for lithium battery pole pieces of claim 3, wherein: The truncated cone of the integrated valve stem has a circular edge with a diameter greater than the bottom circle diameter of the truncated cone, and the height of the circular edge is 1-2mm.

5. The coated web gap valve for lithium battery pole pieces of claim 4, wherein: The maximum opening and closing distance between the truncated cone of the integrated valve stem and the upper opening of the PTFE gasket is 3mm-5mm.

6. The coated web gap valve for lithium battery pole pieces of claim 5, wherein: The conical surface of the truncated cone of the integrated valve stem matches the chamfer at the top of the PTFE gasket.

7. The coated web gap valve for lithium battery pole pieces of claim 6, wherein: The one-piece valve stem is made of 304 stainless steel.

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