Slurry pretreatment device for improving coating effect of positive electrode of lithium battery
The slurry is uniformly heated by the insulation heating tank and the stirring shaft device, which solves the problem of binder floating due to sudden temperature changes during the coating process of the lithium-ion battery electrode sheet, and improves the peel strength and electrical performance stability of the electrode sheet.
Patent Information
- Application Number
- CN202422458985.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-11
- Publication Date
- 2025-08-08
- Estimated Expiration
- 2034-10-11
AI Technical Summary
During the coating process of lithium-ion battery electrode sheet, the adhesive component floats up due to the sudden increase in temperature, which affects the interface adhesion, resulting in a decrease in the peel strength of the dry film electrode sheet and early deterioration during the electrical performance cycle.
The slurry is heated evenly by using a heat-insulating heating tank and a stirring shaft device, increasing the temperature from normal temperature to 45-50°C, and ensuring the uniformity of the slurry temperature through the barrier plate and feeding shell structure to avoid slurry peeling.
The uniform heating of the slurry temperature is achieved, the peeling problem of the slurry during the coating process is avoided, and the peeling strength and electrical performance stability of the dry film electrode sheet are improved.
Smart Images
Figure CN223196864U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of lithium battery positive electrode coating, in particular to a slurry pretreatment device for improving the coating effect of lithium battery positive electrode. Background Art
[0002] Lithium-ion batteries offer advantages such as a high voltage window, high energy density, long cycle life, wide temperature range, and excellent rate performance. They are widely used in large and medium-sized electric devices such as electric vehicles, electric bicycles, power tools, and portable energy storage. With the development of the times, the performance requirements of lithium-ion batteries are becoming increasingly demanding. Electrode production is a fundamental process in lithium-ion battery manufacturing and determines its primary performance. Therefore, how to produce high-quality electrode sheets is currently a key area of focus.
[0003] Currently, lithium-ion battery electrode production all uses room-temperature slurry coating. The coated wet film electrode enters the coating machine oven for baking, and the baked dry film electrode is then reeled up for use. The wet film electrode first experiences relatively low temperatures and air speeds as it travels through the coating machine oven, slowly heating up. After being heated evenly, it enters a high-temperature, high-air-volume zone to accelerate the volatilization of the solvent in the wet film electrode. It then enters a low-temperature, low-air-volume buffer zone to slowly release stress, thereby preventing cracking of the dry film surface due to sudden stress release upon exiting the oven.
[0004] However, when the room temperature slurry enters the coating machine oven, even if the front section of the oven is a low temperature and low wind speed zone, the temperature will rise sharply from room temperature 20-25℃ to 85-90℃. When the temperature rises suddenly, the binder component of the inner layer of the wet film will quickly float to the surface as the solvent evaporates, which will easily cause the binder component at the interface between the coating layer and the current collector to decrease. Later, when it enters the high temperature and high wind volume zone, this floating process will be further intensified, thereby seriously affecting the adhesion at the interface, which will greatly reduce the peel strength of the dry film electrode, and in the electrical performance cycle process, due to poor interface adhesion, the loose interface will show early degradation at a certain point in time.
[0005] To this end, the present application provides a slurry pretreatment device for improving the coating effect of lithium battery positive electrodes. Utility Model Content
[0006] The purpose of the present invention is to provide a slurry pretreatment device for improving the coating effect of lithium battery positive electrodes, so as to solve the problems raised in the above background technology.
[0007] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a slurry pretreatment device for improving the coating effect of lithium battery positive electrode, comprising: a heat-insulating heating tank and a stirring shaft, a cover plate is provided on the top of the heat-insulating heating tank, a drive motor is provided in the center of the top of the cover plate, a stirring shaft is provided at the bottom end of the output shaft of the drive motor, a bottom stirring rod is provided on the outer wall of the bottom of the stirring shaft, a top stirring rod is provided on the outer wall of the upper half of the stirring shaft, a scraper is provided at one end of the bottom stirring rod and the top stirring rod, a material receiving shell is provided at the bottom of the top stirring rod, and a material baffle is provided on the inner wall of the heat-insulating heating tank above the top stirring rod.
[0008] Furthermore, a feed pipe is provided on one side of the cover plate, a discharge valve is provided at the bottom of the thermal insulation heating tank, and a discharge pipe is provided at the bottom of the discharge valve.
[0009] Furthermore, the inner side of the thermal insulation heating tank is an inner liner, the material baffle is fixedly connected to the inner wall of the inner liner, an electric heating wire mesh is provided on the outer side of the inner liner, the outer wall of the inner liner is located outside the electric heating wire mesh and a sandwich steel plate is provided on the outer side of the sandwich steel plate, an insulation layer is provided on the outer side of the insulation layer, and an outer shell is provided on the outer side of the insulation layer.
[0010] Furthermore, the baffle plate is an annular stainless steel plate, the cross section of the baffle plate is an inclined surface, and the end of the baffle plate with a higher inclined surface is connected to the inner wall of the thermal insulation heating tank.
[0011] Furthermore, the top of the material receiving shell is open, and the bottom of the material receiving shell is provided with a discharge port. There are four material receiving shells, and the four material receiving shells are evenly arranged circumferentially on the outside of the stirring shaft.
[0012] Furthermore, one side of the scraper is in contact with the inner wall of the liner, the contact portion between the scraper and the liner is made of silicone, and the liner, the sandwich steel plate and the outer shell are all made of stainless steel.
[0013] Compared with the prior art, the beneficial effects of the present invention are:
[0014] The utility model provides a heat preservation heating tank, a stirring shaft and a baffle plate, so that before the lithium battery positive electrode coating slurry enters the coating machine oven, the slurry is transferred to the heat preservation heating tank after preparation, and the heat preservation heating tank is used to evenly heat the slurry, raising the temperature of the slurry from the normal temperature of 20-25°C to 45-50°C. When entering the oven, the temperature rises more gradually, avoiding the problem of slurry peeling.
[0015] During the heating process of the slurry in the heat-insulating heating tank, a funnel-shaped vortex will be generated in the center of the slurry under the action of centrifugal force. When the slurry at the top of the vortex contacts the baffle plate, the slurry will splash into the receiving shell under the obstruction of the baffle plate. The slurry at the edge of the vortex is transferred to the center of the inner tank through the receiving shell, and the slurry with high edge temperature is quickly transferred to the center, further improving the uniformity of the slurry temperature and ensuring uniform temperature during slurry coating. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 This is a three-dimensional diagram of a slurry pretreatment device for improving the coating effect of lithium battery positive electrodes according to the present invention;
[0017] Figure 2 This is a main cross-sectional view of a slurry pretreatment device for improving the coating effect of lithium battery positive electrodes according to the present invention;
[0018] Figure 3 This is a schematic diagram of the stirring shaft connection structure of a slurry pretreatment device for improving the coating effect of lithium battery positive electrodes in the utility model;
[0019] Figure 4 This is a schematic diagram from another perspective of the stirring shaft connection structure of a slurry pretreatment device for improving the coating effect of lithium battery positive electrodes according to the present invention.
[0020] In the figure: 1. Insulated heating tank; 101. Inner tank; 102. Electric heating wire mesh; 103. Interlayer steel plate; 104. Insulation layer; 105. Outer shell; 2. Cover plate; 3. Drive motor; 4. Feed pipe; 5. Discharge valve; 6. Discharge pipe; 7. Stirring shaft; 8. Bottom stirring rod; 9. Top stirring rod; 10. Scraper; 11. Material receiving shell; 12. Material baffle. DETAILED DESCRIPTION
[0021] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.
[0022] See also Figure 1-Figure 4 The utility model provides a technical solution: a slurry pretreatment device for improving the coating effect of lithium battery positive electrode, comprising: a heat preservation and heating tank 1 and a stirring shaft 7, a cover plate 2 is provided on the top of the heat preservation and heating tank 1, a driving motor 3 is provided in the center of the top of the cover plate 2, a stirring shaft 7 is provided at the bottom end of the output shaft of the driving motor 3, a bottom stirring rod 8 is provided on the outer wall of the bottom of the stirring shaft 7, a top stirring rod 9 is provided on the outer wall of the upper half of the stirring shaft 7, a scraper 10 is provided at one end of the bottom stirring rod 8 and the top stirring rod 9, a material receiving shell 11 is provided at the bottom of the top stirring rod 9, and a material baffle 12 is provided on the inner wall of the heat preservation and heating tank 1 above the top stirring rod 9.
[0023] A feed pipe 4 is provided on one side of the cover plate 2, a discharge valve 5 is provided at the bottom of the thermal insulation and heating tank 1, and a discharge pipe 6 is provided at the bottom of the discharge valve 5. The slurry is transferred to the thermal insulation and heating tank 1 through the feed pipe 4, and is discharged through the discharge valve 5 and the discharge pipe 6 after heating.
[0024] The inner side of the thermal insulation heating tank 1 is an inner liner 101, the baffle plate 12 is fixedly connected to the inner wall of the inner liner 101, an electric heating wire mesh 102 is provided on the outer side of the inner liner 101, and an outer wall of the inner liner 101 is located outside the electric heating wire mesh 102 and is provided with a sandwich steel plate 103, an insulation layer 104 is provided outside the sandwich steel plate 103, and an outer shell 105 is provided outside the insulation layer 104.
[0025] The overall appearance of the thermal insulation heating tank 1 is funnel-shaped. The outer shell 105, insulation layer 104, interlayer steel plate 103, electric heating wire mesh 102 and the upper part of the inner liner 101 are all bent into a barrel shape, with a top-down through-design. The barrel body is 400mm high, and the inner and outer diameters of the upper and lower edges are the same, with an outer diameter of 300mm and an inner diameter of 297mm. The interlayer steel plate 103 is in the middle; the outer shell 105, interlayer steel plate 103 and inner liner steel plate 101 are welded at the upper edge; insulation material is filled between the outer shell 105 and the interlayer steel plate 103 as the insulation layer 104, and the electric heating wire mesh 102 is laid between the interlayer steel plate 103 and the inner liner 101; the outer shell 105 steel plate is 5mm thick, the insulation layer 104 is 10mm thick, the interlayer steel plate 103 is 5mm thick, the electric heating wire mesh 102 is 10mm thick, and the inner liner 101 steel plate is 5mm thick.
[0026] The middle part of the tank body is conical, and the upper edge opening is completely connected with the lower edge of the upper barrel. The outer shell 105, the interlayer steel plate 103, and the inner liner 101 are welded separately, and the insulation layer 104 and the electric heating wire mesh 102 are located in the same position as the upper barrel; at the lower edge of the cone, the interlayer steel plate 103 and the inner liner 101 are welded, and the electric heating wire mesh 102 stops at the weld; the inner diameter of the lower edge of the cone is 20mm, and the outer diameter is 23mm.
[0027] The lower part of the tank body is in the shape of a thin barrel, with a hollow design at the top and bottom, which serves as a discharge pipe 6, and a discharge valve 5 is provided in the middle; the opening on the upper edge of the thin barrel is completely connected with the lower edge of the upper cone, the outer shell 105 and the inner liner 101 are welded separately, and the insulation layer stops at the discharge valve 5; the lower edge of the thin barrel is oblique when viewed from the front, and the outer shell 105 and the inner liner 101 are welded at the lower oblique edge; the inner diameter of the thin barrel is 20mm and the outer diameter is 23mm.
[0028] The outer shell 105, the sandwich steel plate 103 and the inner liner 101 are all made of 304 stainless steel, the insulation layer 104 is polyurethane foam plastic, the electric heating wire mesh 102 is iron-chromium-aluminum alloy, and the high dielectric constant material embedded in the wire opening is PC composite resin.
[0029] The baffle plate 12 is an annular stainless steel plate with an inclined cross section. The end of the baffle plate 12 with a higher inclined surface is connected to the inner wall of the heat preservation and heating tank 1. The top of the material receiving shell 11 is open, and a discharge port is provided at the bottom of the material receiving shell 11. There are four material receiving shells 11, and the four material receiving shells 11 are evenly arranged circumferentially on the outside of the stirring shaft 7. During the rotation of the stirring shaft 7 and the stirring rod, the slurry will generate a funnel-shaped vortex in the center under the action of centrifugal force. When the slurry at the top of the vortex contacts the baffle plate 12, the slurry will splash into the material receiving shell 11 under the obstruction of the baffle plate 12. The slurry at the edge of the vortex is transferred to the center of the inner tank 101 through the material receiving shell 11, and the slurry with high edge temperature is quickly transferred to the center, further improving the uniformity of the slurry temperature and ensuring the uniformity of the temperature when the slurry is applied.
[0030] One side of the scraper 10 abuts against the inner wall of the liner 101. The contact portion between the scraper 10 and the liner 101 is made of silicone. The scraper 10 scrapes off the slurry on the inner wall of the liner 101. The liner 101, the interlayer steel plate 103 and the outer shell 105 are all made of stainless steel.
[0031] Before the lithium battery positive electrode coating slurry enters the coating machine oven, after the slurry is prepared, it is transferred to the heat preservation and heating tank 1, and the heat preservation and heating tank 1 is used to evenly heat the slurry, raising the temperature of the slurry from room temperature 20-25°C to 45-50°C. When entering the oven, the temperature rises more slowly, avoiding the problem of slurry peeling;
[0032] During the heating process of the slurry in the heat preservation and heating tank 1, the inner tank 101 is heated by the electric heating screen 102, and the temperature of the part of the slurry in the heat preservation and heating tank 1 that contacts the inner tank 101 will rise first. In order to ensure the uniformity of the slurry temperature, the driving motor 3 drives the stirring shaft 7 to rotate, and the stirring shaft 7 drives the bottom stirring rod 8 and the top stirring rod 9 to rotate to stir the slurry, and cooperates with the scraper 10 to scrape the slurry on the inner wall of the inner tank 101 to ensure the uniformity of the slurry temperature. In addition, during the rotation of the stirring shaft 7 and the stirring rod, the slurry will generate a funnel-shaped vortex in the center under the action of centrifugal force. When the slurry at the top of the vortex contacts the baffle plate 12, the slurry will splash into the material receiving shell 11 under the obstruction of the baffle plate 12, and the slurry at the edge of the vortex will be transferred to the center of the inner tank 101 through the material receiving shell 11, and the slurry with high edge temperature will be quickly transferred to the center, further improving the uniformity of the slurry temperature and ensuring the uniformity of temperature during slurry coating.
[0033] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of the present invention.
Claims
1. A slurry pretreatment device for improving the coating effect of lithium battery positive electrode, comprising: The heat preservation and heating tank (1) and the stirring shaft (7) are characterized in that: a cover plate (2) is provided on the top of the heat preservation and heating tank (1), a driving motor (3) is provided at the center of the top of the cover plate (2), a stirring shaft (7) is provided at the bottom end of the output shaft of the driving motor (3), a bottom stirring rod (8) is provided on the outer wall of the bottom of the stirring shaft (7), a top stirring rod (9) is provided on the outer wall of the upper half of the stirring shaft (7), a scraper (10) is provided at one end of the bottom stirring rod (8) and the top stirring rod (9), a material receiving shell (11) is provided at the bottom of the top stirring rod (9), and a material blocking plate (12) is provided on the inner wall of the heat preservation and heating tank (1) above the top stirring rod (9).
2. The slurry pretreatment device for improving the coating effect of lithium battery positive electrode according to claim 1, characterized in that: A feed pipe (4) is provided on one side of the cover plate (2), a discharge valve (5) is provided at the bottom of the heat-insulating heating tank (1), and a discharge pipe (6) is provided at the bottom of the discharge valve (5).
3. The slurry pretreatment device for improving the coating effect of lithium battery positive electrode according to claim 1, characterized in that: The inner side of the heat-insulating heating tank (1) is an inner liner (101), the material blocking plate (12) is fixedly connected to the inner wall of the inner liner (101), the outer side of the inner liner (101) is provided with an electric heating wire mesh (102), the outer wall of the inner liner (101) is located outside the electric heating wire mesh (102) and is provided with a sandwich steel plate (103), the outer side of the sandwich steel plate (103) is provided with a heat-insulating layer (104), and the outer side of the heat-insulating layer (104) is provided with an outer shell (105).
4. The slurry pretreatment device for improving the coating effect of lithium battery positive electrode according to claim 1, characterized in that: The baffle plate (12) is a ring-shaped stainless steel plate. The cross section of the baffle plate (12) is an inclined surface. The end of the baffle plate (12) with a higher inclined surface is connected to the inner wall of the heat preservation and heating tank (1).
5. The slurry pretreatment device for improving the coating effect of lithium battery positive electrode according to claim 4, characterized in that: The top of the material receiving shell (11) is open, and the bottom of the material receiving shell (11) is provided with a discharge port. There are four material receiving shells (11), and the four material receiving shells (11) are evenly arranged in the circumferential direction outside the stirring shaft (7).
6. The slurry pretreatment device for improving the coating effect of lithium battery positive electrode according to claim 3, characterized in that: One side of the scraper (10) abuts against the inner wall of the inner container (101); the contact portion between the scraper (10) and the inner container (101) is made of silicone; the inner container (101), the sandwich steel plate (103) and the outer shell (105) are all made of stainless steel.