Tool for solving edge cracking in coating and baking process of lithium battery negative plate

Abstract

The utility model discloses a tool for solving the problem of edge cracking in the coating and baking process of a lithium battery negative electrode plate, which comprises a wind shield arranged at an air nozzle of a baking oven, a thinning area positioned on the electrode plate and used for reducing the flow velocity and heat transfer area of convection air, and a heat transfer plate arranged at the air nozzle of the baking oven, the wind shield is of a U-shaped structure, and the wind shield is arranged on the air nozzle of the drying oven in a sleeving manner; the wind shield comprises a bottom plate and two connecting plates, and the two connecting plates are symmetrically arranged on the bottom plate; a connecting hole is formed in the connecting plate; during installation, bolts penetrate through the connecting holes to fix the wind shield to the drying oven, and airflow blown out by a drying oven tuyere is blocked; the convection air speed and the heat transfer area borne by the pole piece thinning area located right above the wind shield are reduced, the drying rate lower than the drying rate of the central area of the pole piece is shown, and the phenomenon of edge cracking is effectively reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of lithium battery production, and in particular relates to a tool for solving edge cracking in the coating and baking process of a lithium battery negative electrode sheet. Background Art

[0002] The coating process of lithium-ion battery manufacturing is a process of evenly coating the positive and negative electrode slurries on the foil sheet and then drying them to form a film. The drying oven equipment plays the role of wet film curing, and its drying effect directly affects the quality of the electrode. At present, the most commonly used coating oven is the convection drying form. In order to provide more hot air to the electrode and thus increase the drying effect, the length of the oven nozzle outlet is generally set to be equal to the length of the roller.

[0003] However, at this time, the width of the electrode will be smaller than the length of the nozzle outlet. The excess hot air at both ends of the outlet will over-dry the thinned area of ​​the electrode, that is, the edge of the electrode. In severe cases, it will cause coating defects such as edge cracks, affecting the quality of the lithium battery electrode.

[0004] Therefore, how to reduce the flow rate and heat transfer area of ​​the convective air in the thinning zone, thereby reducing the drying rate and reducing the occurrence of cracking defects in the edge thinning zone, is a problem that needs to be solved at present. Utility Model Content

[0005] Purpose of the utility model: To provide a tool for solving the edge cracking during the coating and baking process of the negative electrode sheet of a lithium battery, so as to solve the above-mentioned problems existing in the prior art.

[0006] Technical solution: A tool to solve the edge cracking during the coating and baking process of lithium battery negative electrode sheets, including:

[0007] The wind shield plate installed at the oven air nozzle is located in the thinning area of ​​the pole piece to reduce the flow rate and heat transfer area of ​​the convective air;

[0008] The wind shield is a U-shaped structure, and the wind shield is sleeved on the oven air nozzle;

[0009] The wind shield plate comprises a bottom plate and two connecting plates, and the two connecting plates are symmetrically arranged on the bottom plate;

[0010] A connecting hole is provided on the connecting plate;

[0011] During installation, bolts penetrate the connection holes to fix the wind shield on the oven, thereby blocking the airflow blown out of the oven nozzle.

[0012] In a further embodiment, the length of the area where the wind shield is parallel to the oven air nozzle is greater than the width of the oven air nozzle; thereby facilitating the sliding wind shield to be adjusted anywhere, thereby ensuring smooth adjustment of the wind shield.

[0013] In a further embodiment, two chamfers are symmetrically provided in the length direction of the top of the oven air nozzle.

[0014] In a further embodiment, a plurality of air outlets are evenly arranged on the top of the oven air nozzle;

[0015] The wind shield is used to shield the designated air outlet.

[0016] In a further embodiment, the length direction of the wind shield is perpendicular to the air outlet direction of the oven air nozzle.

[0017] Beneficial effect: The utility model relates to a tooling for solving the edge cracking during the coating and baking process of the negative electrode sheet of a lithium battery. In order to reduce the flow rate and heat transfer area of ​​the convective air in the thinning zone, thereby reducing the drying rate and reducing the occurrence of cracking defects in the edge thinning zone, before the oven is turned on, the wind shield is first pushed to move the wind shield on the oven air nozzle, so that the wind shield is located near the thinning zone of the electrode sheet, and then the wind shield is fixed to the oven air nozzle by bolts, and then the oven is turned on. At this time, the fresh air blown out from the air outlet of the air nozzle is blocked by the upper wind shield, and then blows in the direction of both sides of the width of the baffle. At this time, the convective air velocity and heat transfer area of ​​the electrode sheet thinning zone located directly above the wind shield are reduced, showing a drying rate lower than that of the central area of ​​the electrode sheet, effectively reducing the phenomenon of edge cracking; at the same time, based on the principle of cost saving, on the basis of not changing the original oven structure, a simple device is added to solve the defects in the existing coating production, making the oven air nozzle more practical and economical. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the structure of a tooling proposed by the utility model to solve the edge cracking of the negative electrode sheet of a lithium battery during coating and baking;

[0019] Figure 2 This is a front view of a tool proposed by the utility model for solving edge cracking during coating and baking of negative electrode sheets of lithium batteries.

[0020] Figure 3 This is a top view of a tooling proposed by the utility model for solving the problem of edge cracking during coating and baking of negative electrode sheets of lithium batteries.

[0021] Figure 4 This is a left view of a tool proposed by the utility model for solving the problem of edge cracking during the coating and baking process of the negative electrode sheet of a lithium battery.

[0022] Figure 5 The utility model is a structural schematic diagram of a tuyere device equipped with a baffle provided by the utility model.

[0023] The reference numerals in the figures are: wind shield 1, connecting hole 2, bolt 3, oven air nozzle 4, air outlet 5. DETAILED DESCRIPTION

[0024] After research and analysis by the applicant, the reason for this problem (cracking in the edge thinning area) is that the width of the electrode piece is smaller than the length of the nozzle outlet, and the excess hot air at both ends of the outlet will over-dry the thinning area of ​​the electrode piece. In severe cases, it will cause coating defects such as edge cracking, affecting the quality of the lithium battery electrode piece. In order to reduce the flow rate and heat transfer area of ​​the convective air in the thinning area, thereby reducing the drying rate and reducing the occurrence of cracking defects in the edge thinning area, before the oven is started, the wind shield is first pushed to move the wind shield on the oven nozzle, and then the wind shield is located near the thinning area of ​​the electrode piece. At this time, the fresh air blown out from the nozzle outlet is blocked by the upper wind shield, and then blows in the direction of both sides of the baffle width. At this time, the pole piece thinning area located directly above the wind shield is subject to reduced convective air velocity and heat transfer area, showing a lower drying rate than the central area of ​​the pole piece, effectively reducing the edge cracking phenomenon; at the same time, based on the principle of cost saving, without changing the original oven structure, the defects in the existing coating production are solved by adding a simple device, making the oven nozzle more practical and economical.

[0025] A tool for solving edge cracking during coating and baking of a lithium battery negative electrode sheet comprises: a wind shield 1, a connection hole 2, a bolt 3, an oven air nozzle 4, and an air outlet 5.

[0026] The device comprises a windshield 1 arranged at the oven air nozzle 4, located in the thinning area of ​​the pole piece, and used to reduce the flow rate and heat transfer area of ​​the convective air; the windshield 1 arranged at the oven air nozzle 4 is located in the thinning area of ​​the pole piece and used to reduce the flow rate and heat transfer area of ​​the convective air; the windshield 1 is a U-shaped structure, and the windshield 1 is sleeved on the oven air nozzle 4; the windshield 1 is a bottom plate and two connecting plates, and the two connecting plates are symmetrically arranged on the bottom plate; a connecting hole 2 is opened on the connecting plate; during installation, the bolt 3 passes through the connecting hole 2 to fix the windshield 1 on the oven to block the air flow blown out of the oven air nozzle 4; in the device, before the oven is started, the windshield 1 is first pushed to move the windshield 1 on the oven air nozzle 4, and then the windshield 1 is located near the thinning area of ​​the pole piece. At this time, the fresh air blown out from the air outlet 5 of the air nozzle is blocked by the upper windshield 1, and then blows in the direction of both sides of the width of the windshield. At this time, the pole piece thinning area located directly above the wind shield 1 is subjected to reduced convective air velocity and heat transfer area, showing a lower drying rate than the central area of ​​the pole piece, effectively reducing the edge cracking phenomenon; at the same time, based on the principle of cost saving, without changing the original oven structure, the defects in the existing coating production are solved by adding a simple device, making the oven nozzle 4 more practical and economical.

[0027] The oven air nozzle 4 is symmetrically provided with two grooves in the length direction, and a slider slidably connected to the grooves; the slider is connected to the wind shield 1; the top of the oven air nozzle 4 is symmetrically provided with two chamfers in the length direction; through the provided grooves and sliders, the slider can be moved in the grooves, so as to facilitate the adjustment of the position of the wind shield 1 in the length direction of the oven air nozzle 4, so as to facilitate its location in the thinning area of ​​the electrode; at the same time, the wind shield 1 can be flexibly disassembled and assembled, and is suitable for the drying process of electrodes of various widths, providing a unified and effective way to solve common problems such as cracking in the thinning area of ​​the edge of the lithium battery electrode; through the provided chamfers, the collision between the wind shield 1 and the oven air nozzle 4 during the movement can be avoided, so as to avoid damage to both.

[0028] The length of the area parallel to the air nozzle 4 of the oven is greater than the width of the air nozzle 4 of the oven, so that the air shield 1 can be translated in the length direction of the air nozzle.

[0029] A plurality of air outlets 5 are evenly arranged on the top of the oven air nozzle 4; the wind shield 1 is used to shield the designated air outlet 5; the surface of the electrode can be dried through the arranged air outlet 5.

[0030] The length direction of the wind shield 1 is perpendicular to the direction of the air outlet 5 of the oven air nozzle 4; the wind shield 1 can block the blown hot air.

[0031] Working principle description: before starting the oven, first push the wind shield 1 to move it on the oven nozzle 4, so that the wind shield 1 is located near the thinning area of ​​the pole piece, then fix the wind shield 1 on the oven nozzle 4 by bolts 3, and then turn on the oven. At this time, the fresh air blown out from the nozzle outlet 5 is blocked by the wind shield 1 above, and blows in the direction of both sides of the baffle width. At this time, the pole piece thinning area located directly above the wind shield 1 has a reduced convection air velocity and heat transfer area, showing a lower drying rate than the central area of ​​the pole piece, effectively reducing the edge cracking phenomenon.

[0032] As described above, although the present invention has been shown and described with reference to specific preferred embodiments, it should not be interpreted as limiting the present invention itself. Various changes can be made to it in form and detail without departing from the spirit and scope of the present invention defined in the appended claims.

Claims

1. A tool for solving edge cracking during coating and baking of negative electrode sheets of lithium batteries, characterized in that: include: The wind shield plate installed at the oven air nozzle is located in the thinning area of ​​the pole piece to reduce the flow rate and heat transfer area of ​​the convective air; The wind shield is a U-shaped structure, and the wind shield is sleeved on the oven air nozzle; The wind shield plate comprises a bottom plate and two connecting plates, and the two connecting plates are symmetrically arranged on the bottom plate; A connecting hole is provided on the connecting plate; During installation, bolts penetrate the connection holes to fix the wind shield on the oven, thereby blocking the airflow blown out of the oven nozzle.

2. A tool for solving edge cracking during coating and baking of lithium battery negative electrode sheets according to claim 1, characterized in that: The oven air nozzle is symmetrically provided with two grooves in the length direction, and a sliding block slidably connected to the grooves; The sliding block is connected with the wind shield.

3. A tool for solving edge cracking during coating and baking of negative electrode sheets of lithium batteries according to claim 1, characterized in that: The length of the area where the wind shield is parallel to the oven air nozzle is greater than the width of the oven air nozzle.

4. The tooling for solving edge cracking during coating and baking of negative electrode sheets of lithium batteries according to claim 1, characterized in that: The top of the oven air nozzle is symmetrically provided with two chamfers in the length direction.

5. The tooling for solving edge cracking during coating and baking of negative electrode sheets of lithium batteries according to claim 1, characterized in that: A plurality of air outlets are evenly arranged on the top of the oven air nozzle; The wind shield is used to shield the designated air outlet.

6. The tooling for solving edge cracking during coating and baking of negative electrode sheets of lithium batteries according to claim 1, characterized in that: The length direction of the wind shield is perpendicular to the air outlet direction of the oven air nozzle.

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