A semi-solid electrolyte coating apparatus and method

Abstract

This invention relates to the field of semi-solid electrolyte production equipment technology, specifically to a semi-solid electrolyte coating equipment and coating method, comprising a support; a guiding and conveying mechanism for guiding the movement of a diaphragm; a pretreatment mechanism for pretreatment of the slurry; a slurry coating mechanism for coating the slurry onto the diaphragm; and a drying and shaping mechanism for drying the coated slurry. The guiding and conveying mechanism is mounted on the support, the pretreatment mechanism is mounted on one side of the support, the slurry coating mechanism is mounted on the pretreatment mechanism, and the drying and shaping mechanism is mounted at the end of the support away from the slurry coating mechanism. A low-pressure drying environment is created by a low-pressure chamber and a fan, thereby significantly reducing the solvent boiling point and allowing the solvent to rapidly vaporize and evaporate at low temperatures. Furthermore, the low-temperature drying characteristic prevents rapid skin formation on the coating surface, allowing the solvent to escape uniformly from the inside out, fundamentally preventing drying defects such as bubbling, cracking, and curling.

Description

Technical Field

[0001] This invention relates to the field of semi-solid electrolyte production equipment technology, specifically to a semi-solid electrolyte coating equipment and coating method. Background Technology

[0002] Semi-solid electrolytes are battery electrolyte materials that fall between liquid and all-solid electrolytes. They are typically composed of a solid electrolyte matrix mixed with a small amount of liquid electrolyte, forming a gel-like or composite state. For semi-solid systems, the slurry is usually more viscous and has a higher solid content, making solvent removal more difficult. Therefore, drying the wet coating after processing is a crucial step in determining the electrode's microstructure, mechanical integrity, and electrochemical performance. Current technologies widely employ convective hot air drying for wet coatings. This technology uses high-temperature hot air to blow onto the surface of the wet coating, providing heat through convection and conduction to evaporate the solvent. However, hot air drying is limited by air humidity and heat exchange, resulting in very low drying efficiency. Therefore, to increase drying efficiency, the hot air temperature is generally increased to improve solvent evaporation efficiency; however, increasing the hot air temperature introduces new drawbacks.

[0003] The hot air first heats the coating surface, causing the surface solvent to evaporate rapidly. This easily leads to the premature migration and accumulation of surface binders and solid particles, forming a dense, hard shell. This shell severely hinders the escape channels of internal solvent vapor. As the internal solvent continues to vaporize under heat, it generates enormous vapor pressure, eventually bursting the surface and causing irreversible defects such as blistering, cracking, and curling. These defects directly damage the continuity of the conductive network in the electrode coating and become the starting point for side reactions and failures during battery cycling. Furthermore, increasing the temperature to achieve drying efficiency can damage heat-sensitive materials, causing polymer binder molecular chains to break or remodel, and adverse phase transitions to occur on the surface of some active materials, thereby degrading the interfacial stability and long-term cycling performance of the electrode.

[0004] In view of this, we propose a semi-solid electrolyte coating device and coating method. Summary of the Invention

[0005] The purpose of this invention is to provide a semi-solid electrolyte coating device and coating method, which solves the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A semi-solid electrolyte coating device, including a support; A guiding and conveying mechanism is used to guide the movement of the diaphragm; Pretreatment unit, used for pretreatment of slurry; A slurry coating mechanism for coating slurry onto a diaphragm; The drying and setting mechanism is used to dry the coated slurry. The guiding and conveying device is mounted on the support, the pretreatment mechanism is mounted on one side of the support, the slurry coating mechanism is mounted on the pretreatment mechanism, and the drying and shaping mechanism is mounted on the end of the support away from the slurry coating mechanism.

[0007] Preferably, the guiding and conveying mechanism includes a conveying roller, which is rotatably connected to a support. A drive motor is fixedly connected to the support, and the output end of the drive motor passes through the support and is fixedly connected to one end of the conveying roller.

[0008] Preferably, the pretreatment mechanism includes a mixing tank, which is fixedly connected to a support. A aging tank is connected to one side of the mixing tank via a pipe. A blower is fixedly connected to the top of the aging tank via a pipe, and the blower is connected to the interior of the aging tank via a pipe.

[0009] Preferably, the slurry coating mechanism includes a conveying pipe that is connected to an aging tank. An ultrasonic generator is provided on the conveying pipe, and an ultrasonic probe is fixedly connected to the ultrasonic generator. The ultrasonic probe is disposed through the side wall of the conveying pipe.

[0010] Preferably, the conveying pipeline is equipped with a back pressure valve, one end of the conveying pipeline is fixedly connected to a coating head, the other end of the conveying pipeline is connected to a liquid pump, and the conveying pipeline is equipped with a cooling component.

[0011] Preferably, the cooling assembly includes a cooling pipe that is wound around the outside of the delivery pipe, the cooling pipe is disposed on both sides of the ultrasonic generator, and a heat exchanger is fixedly connected to the end of the cooling pipe.

[0012] Preferably, the drying and shaping mechanism includes a low-pressure box, which is fixedly connected to the top of the support. The low-pressure box has through holes at the bottom of both sides, and a support roller is rotatably connected to one side of the through hole.

[0013] Preferably, there are several low-pressure boxes, which are arranged adjacent to each other and connected to each other through through holes. A second fan is fixedly connected to the top of each low-pressure box, and a heating device is fixedly connected inside each low-pressure box.

[0014] A semi-solid electrolyte coating method, used in a semi-solid electrolyte coating apparatus as described in any of the above claims, includes the following steps: S1. Slurry mixing treatment: Add the slurry raw materials into the mixing tank and continuously mix the slurry at the set mixing rate; S2. Online ultrasonic treatment of slurry: The semi-solid electrolyte slurry mixed in step S1 is continuously transported to the coating head through a conveying pipeline. During the conveying process, the slurry flows through an ultrasonic probe, and pulsed ultrasound is used to homogenize the flowing slurry online. S3. Precision coating of homogeneous slurry: The slurry processed in step S2 is continuously coated onto the moving substrate through a slit extrusion coating head to form a wet coating. S4. Segmented low-pressure drying of wet coating: The wet coating is passed through at least two drying stages in sequence. The drying stages are under normal or low pressure conditions, and the pressure difference between two adjacent stages is 10-50 kPa and the temperature difference between two adjacent stages is 10-20°C. The coating is then dried to a final depth to completely remove residual solvent.

[0015] Preferably, step S2 further includes applying back pressure to the slurry while it flows through the ultrasonic probe during the conveying process, maintaining the pressure in the ultrasonic treatment section of the conveying pipeline where the ultrasonic probe is located greater than 0.2 MPa.

[0016] By employing the above technical solution, the present invention provides a semi-solid electrolyte coating device and coating method that have at least the following beneficial effects: (1) The present invention creates a low-pressure drying environment by setting a low-pressure box and a fan, thereby significantly reducing the boiling point of the solvent and enabling the solvent to vaporize and evaporate rapidly at low temperature. At the same time, the solvent vapor pressure difference and concentration gradient formed inside and outside the coating improve the evaporation effect of the solvent. In addition, the low-temperature drying characteristics prevent the rapid skin formation on the coating surface, allowing the solvent to escape evenly from the inside to the outside, fundamentally preventing the generation of drying defects such as bubbling, cracking, and curling. On the other hand, the low-temperature environment avoids damage to heat-sensitive materials, allowing the uniform microstructure formed by the coating to be solidified and preserved during the drying process.

[0017] (2) The present invention utilizes the cavitation effect and acoustic flow effect generated in the flowing slurry by the ultrasonic generator and ultrasonic probe. The micro-jet and shock wave generated by the cavitation effect can effectively break up the agglomerates of particles, while the acoustic flow effect promotes the overall macroscopic uniform mixing of the slurry. By applying controllable back pressure in the conveying pipeline through the back pressure valve, excessive cavitation can be suppressed, making the treatment more gentle and controllable. Attached Figure Description

[0018] The accompanying drawings, which are provided to further illustrate the invention, constitute a part of this application: Figure 1 This is a schematic diagram of the structure of the present invention. Figure 1 ; Figure 2 This is a schematic diagram of the structure of the present invention. Figure 2 ; Figure 3This is a schematic diagram of the internal structure of the drying and shaping mechanism of the present invention; Figure 4 This is a schematic diagram of the internal structure of the aging tank of the present invention; Figure 5 This is a schematic diagram of the internal structure of the conveying pipeline of the present invention; Figure 6 In this invention Figure 5 Enlarged diagram of point A.

[0019] In the diagram: 1. Support frame; 2. Guiding and conveying mechanism; 21. Conveying roller; 22. Drive motor; 3. Pretreatment mechanism; 31. Mixing tank; 32. Aging tank; 33. Fan 1; 4. Slurry coating mechanism; 41. Conveying pipe; 42. Ultrasonic generator; 43. Ultrasonic probe; 44. Back pressure valve; 45. Coating head; 47. Cooling assembly; 471. Cooling pipe; 472. Heat exchanger; 5. Drying and shaping mechanism; 51. Low-pressure box; 52. Through hole; 53. Support roller; 54. Fan 2; 55. Heating device. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] Example 1 A semi-solid electrolyte coating device, such as Figures 1-6 As shown, it includes a support 1; a guiding and conveying mechanism 2 is provided on the support 1 for guiding the movement of the diaphragm; a pretreatment mechanism 3 is provided on one side of the support 1 for pretreatment of the slurry; a slurry coating mechanism 4 is provided on the pretreatment mechanism 3 for coating the slurry onto the diaphragm; a drying and shaping mechanism 5 is provided at the end of the support 1 away from the slurry coating mechanism 4 for drying the coated slurry.

[0022] Specifically, the guiding and conveying mechanism 2 includes a conveying roller 21, which is rotatably connected to the support 1. A drive motor 22 is fixedly connected to the support 1, and the output end of the drive motor 22 passes through the support 1 and is fixedly connected to one end of the conveying roller 21. The conveying roller 21 is used to guide and convey the diaphragm, so that the diaphragm substrate can move from one end of the support 1 to the other end. There are several conveying rollers 21, including unwinding rollers and take-up rollers located at both ends of the support 1. The drive motor 22 is used to drive the unwinding rollers and take-up rollers. The remaining take-up rollers are rotatably connected to the support 1 and passively rotate during the movement of the diaphragm to support the diaphragm and adjust the surface tension of the diaphragm so that the diaphragm reaches a flat state before coating.

[0023] It is worth noting that the pretreatment unit 3 includes a mixing tank 31, which is fixedly connected to the support 1. One side of the mixing tank 31 is connected to an aging tank 32 via a pipe. The top of the aging tank 32 is fixedly connected to a blower 33 via a pipe, and the blower 33 is connected to the interior of the aging tank 32 via a pipe. The mixing tank 31 is used for continuous mixing of the slurry raw materials. Inside the mixing tank 31, stirring blades and a stirring rod for mounting and supporting the stirring blades are rotatably connected, allowing the stirring blades to rotate inside the mixing tank 31 to mix the slurry raw materials. The aging tank 32 is used to place and age the mixed slurry raw materials. Static aging allows the internal structure of the slurry to slowly rebuild and stabilize, achieving optimal thixotropy, viscosity, and yield stress. The blower 33 is used to exhaust gas from the aging tank 32, thereby reducing the internal gas pressure of the aging tank 32. This allows the bubbles generated during the mixing process of the high-viscosity slurry to be quickly discharged. At the same time, the low pressure state can be combined with the atmospheric or high-pressure gas in the mixing tank 31 to compress the slurry after mixing, increasing the speed at which the high-viscosity slurry flows from the mixing tank 31 to the aging tank 32. The mixing tank 31 and the aging tank 32 are connected to each other by a pipeline, and a control valve is installed on the pipeline.

[0024] Based on this, the slurry coating mechanism 4 includes a conveying pipe 41, which is connected to the aging tank 32. An ultrasonic generator 42 is installed on the conveying pipe 41, and an ultrasonic probe 43 is fixedly connected to the ultrasonic generator 42. The ultrasonic probe 43 passes through the side wall of the conveying pipe 41. The conveying pipe 41 is used to extract the aged slurry from the aging tank 32. The ultrasonic probe 43 is used to apply the ultrasonic waves generated by the ultrasonic generator 42 to the flowing slurry inside the conveying pipe 41. When the ultrasonic waves propagate in the liquid, they generate high-frequency pressure changes, forming countless tiny vacuum bubbles that burst violently and instantaneously. This process generates extremely strong local impact force, high temperature, and high-speed microjets, effectively breaking up particle agglomerates in the slurry, improving the dispersion effect, and simultaneously destroying the internal network structure of the slurry, significantly reducing its apparent viscosity and yield stress, thus improving its fluidity.

[0025] In addition, a back pressure valve 44 is provided on the delivery pipe 41. A coating head 45 is fixedly connected to one end of the delivery pipe 41, and a liquid pump is connected to the other end of the delivery pipe 41. A cooling component 47 is provided on the delivery pipe 41. The back pressure valve 44 can be directly set and stably maintained at the required pressure. At the same time, the pressure can be independently adjusted without affecting the ultrasonic treatment while ensuring the flow rate. At the same time, the back pressure valve 44 can reduce the jerking caused by the liquid pump during operation, provide a stable system pressure, and thus improve the process stability. The coating head 45 is used to coat the slurry onto the surface of the diaphragm substrate. When the slurry passes through the coating head 45, the velocity gradient at the gaps increases by orders of magnitude, and the shear rate of the high-viscosity slurry increases rapidly, thereby stretching the slurry into a uniform film. At the same time, the high shear rate is used to achieve effective homogenization by finally mixing the slurry. The cooling component 47 is used to cool and reduce the temperature of the ultrasonic generator 42 and the ultrasonic area acting on the delivery pipe 41, so as to avoid the local temperature rise of the slurry caused by the large amount of heat generated during the ultrasonic process, which accelerates the evaporation of low-boiling-point solvents or reduces the adsorption stability of the dispersant.

[0026] Based on this, the cooling assembly 47 includes a cooling pipe 471, which is wrapped around the outside of the delivery pipe 41. The cooling pipe 471 is arranged on both sides of the ultrasonic generator 42. A heat exchanger 472 is fixedly connected to the end of the cooling pipe 471. The cooling pipe 471 is used to transport cooling water, thereby cooling the section of the delivery pipe 41 that is subjected to ultrasonic action. The heat exchanger 472 is used to exchange heat between the cooling pipe 471 and the external environment, quickly reducing the temperature of the internal cooling water and keeping the cooling water within the room temperature range.

[0027] It is worth noting that the drying and shaping mechanism 5 includes a low-pressure box 51, which is fixedly connected to the top of the support 1. Through holes 52 are provided on both sides of the low-pressure box 51, and a support roller 53 is rotatably connected to one side of each through hole 52. Several low-pressure boxes 51 are provided, arranged adjacent to each other, and connected to each other through the through holes 52. A second fan 54 is fixedly connected to the top of the low-pressure box 51, and a heating device 55 is fixedly connected inside the low-pressure box 51. In this design, the heating device 55 uses an infrared heating tube. The low-pressure box 51 is used to heat the support 1. Multiple semi-sealed structures are formed on the surface, and together with fan 54, a low-pressure environment is created to improve the drying effect on the coating slurry. Several low-pressure boxes 51 are arranged in a straight line and interconnected. At the same time, the air pressure inside several low-pressure boxes 51 decreases in a stepped manner under the action of fan 54, so that the pressure difference between adjacent low-pressure boxes 51 or between low-pressure boxes 51 and the external environment is kept within a low range. This keeps the air velocity entering the low-pressure box 51 from the through hole 52 within a low range, avoiding the formation of strong jets that blow away the coating due to excessive air velocity. At the same time, when the low-pressure box 51 is under low-pressure conditions, the solvent boiling point decreases, thereby improving the drying effect on the coating slurry. In addition, the low-pressure environment reduces the solvent vapor partial pressure on the coating surface to an extremely low level, which maximizes the solvent concentration gradient and vapor pressure difference between the inside and the surface of the coating. After the solvent vaporizes, it forms bubbles or vapor, which are more likely to expand and escape quickly through the pores of the wet coating under low-pressure conditions, reducing the risk of bubbles being trapped inside and forming defects.

[0028] Example 2 A semi-solid electrolyte coating method includes the following steps: S1. Slurry mixing treatment: Add the slurry raw materials into the mixing tank 31 and continuously mix the slurry by the set mixing rate; S2. Online ultrasonic treatment of slurry: The semi-solid electrolyte slurry mixed in step S1 is continuously transported to the coating head 45 through the conveying pipe 41. During the conveying process, the slurry flows through the ultrasonic probe 43, and back pressure is applied to the slurry to maintain the pressure in the ultrasonic treatment section of the conveying pipe 41 where the ultrasonic probe 43 is located greater than 0.2 MPa. Pulsed ultrasound is used to homogenize the flowing slurry online. S3. Precision coating of homogeneous slurry: The slurry processed in step S2 is continuously coated onto the moving substrate through a slit extrusion coating head 45 to form a wet coating. S4. Segmented low-pressure drying of wet coating: The wet coating is passed through at least two drying stages in sequence. The drying stages are under normal or low pressure conditions, and the pressure difference between two adjacent stages is 10-50 kPa, and the temperature difference between two adjacent stages is 10-20°C. In this embodiment, this step includes two drying stages. The first stage is under 40 kPa and 50°C for preliminary curing to set the coating surface. The second stage is under 10 kPa and 70°C for final deep drying to completely remove residual solvent.

[0029] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0030] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A semi-solid electrolyte coating device, characterized in that: Including the support (1); The guiding and conveying mechanism (2) is used to guide the movement of the diaphragm; Pretreatment unit (3) is used to pretreatment slurry; A slurry coating mechanism (4) is used to coat slurry onto the diaphragm; The drying and shaping mechanism (5) is used to dry the coated slurry; The guiding and conveying device is set on the support (1), the pretreatment mechanism (3) is set on one side of the support (1), the slurry coating mechanism (4) is set on the pretreatment mechanism (3), and the drying and shaping mechanism (5) is set on the end of the support (1) away from the slurry coating mechanism (4).

2. The semi-solid electrolyte coating equipment according to claim 1, characterized in that: The guiding conveying mechanism (2) includes a conveying roller (21), which is rotatably connected to a bracket (1). A drive motor (22) is fixedly connected to the bracket (1). The output end of the drive motor (22) passes through the bracket (1) and is fixedly connected to one end of the conveying roller (21).

3. The semi-solid electrolyte coating equipment according to claim 1, characterized in that: The pretreatment mechanism (3) includes a mixing tank (31), which is fixedly connected to the support (1). A aging tank (32) is connected to one side of the mixing tank (31) through a pipe. A blower (33) is fixedly connected to the top of the aging tank (32) through a pipe. The blower (33) is connected to the inside of the aging tank (32) through a pipe.

4. The semi-solid electrolyte coating equipment according to claim 1, characterized in that: The slurry coating mechanism (4) includes a conveying pipe (41) which is connected to an aging tank (32). An ultrasonic generator (42) is provided on the conveying pipe (41), and an ultrasonic probe (43) is fixedly connected to the ultrasonic generator (42). The ultrasonic probe (43) is installed through the side wall of the conveying pipe (41).

5. The semi-solid electrolyte coating equipment according to claim 4, characterized in that: The conveying pipe (41) is equipped with a back pressure valve (44), one end of the conveying pipe (41) is fixedly connected to a coating head (45), the other end of the conveying pipe (41) is connected to a liquid pump, and the conveying pipe (41) is equipped with a cooling assembly (47).

6. The semi-solid electrolyte coating equipment according to claim 5, characterized in that: The cooling assembly (47) includes a cooling pipe (471) which is wrapped around the outside of the delivery pipe (41). The cooling pipe (471) is arranged on both sides of the ultrasonic generator (42), and a heat exchanger (472) is fixedly connected to the end of the cooling pipe (471).

7. The semi-solid electrolyte coating device according to claim 1, characterized in that: The drying and shaping mechanism (5) includes a low-pressure box (51), which is fixedly connected to the top of the support (1). The low-pressure box (51) has through holes (52) at the bottom of both sides, and a support roller (53) is rotatably connected to one side of the through hole (52).

8. The semi-solid electrolyte coating device according to claim 7, characterized in that: The low-pressure box (51) is provided in several pairs, and the low-pressure boxes (51) are arranged adjacent to each other and connected to each other through through holes (52). A second fan (54) is fixedly connected to the top of the low-pressure box (51), and a heating device (55) is fixedly connected inside the low-pressure box (51).

9. A method for coating a semi-solid electrolyte, used in a semi-solid electrolyte coating apparatus as described in any one of claims 1-8, characterized in that, Includes the following steps: S1. Slurry mixing treatment: Add the slurry raw materials into the mixing tank (31) and continuously mix the slurry by the set mixing rate; S2. Online ultrasonic treatment of slurry: The semi-solid electrolyte slurry mixed in step S1 is continuously transported to the coating head (45) through the conveying pipe (41). During the conveying process, the slurry flows through the ultrasonic probe (43) and pulsed ultrasound is used to homogenize the flowing slurry online. S3, Precision coating of homogeneous slurry: The slurry processed in step S2 is continuously coated onto the moving substrate through a slit extrusion coating head (45) to form a wet coating; S4. Segmented low-pressure drying of wet coating: The wet coating is passed through at least two drying stages in sequence. The drying stages are under normal or low pressure conditions, and the pressure difference between two adjacent stages is 10-50 kPa and the temperature difference between two adjacent stages is 10-20°C. The coating is then dried to a final depth to completely remove residual solvent.

10. A semi-solid electrolyte coating method according to claim 9, characterized in that: Step S2 further includes applying back pressure to the slurry while it flows through the ultrasonic probe (43) during the conveying process, maintaining the pressure in the ultrasonic treatment section of the conveying pipe (41) where the ultrasonic probe (43) is located greater than 0.2 MPa.

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