Membrane preparation device
By combining a freezing chamber and a drying chamber, and utilizing temperature gradient freezing and sublimation drying treatment, the problems of prolonged electrolyte infiltration time and reduced rate performance caused by increased electrode thickness in lithium-ion batteries were solved, thus realizing the design of high-energy-density batteries.
Patent Information
- Application Number
- CN202422661152.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-01
- Publication Date
- 2025-10-28
- Estimated Expiration
- 2034-11-01
AI Technical Summary
In existing lithium-ion batteries, as the active material loading increases, the electrode thickness increases, resulting in prolonged electrolyte infiltration time and reduced rate performance.
A combination of a freezing chamber and a drying chamber is used, and temperature gradient freezing and sublimation drying treatment are used to form an oriented pore structure perpendicular to the direction of the membrane, which promotes the rapid transmission of electrolyte ions and reduces the internal exciton transmission resistance.
It improves the rate performance and energy density of the battery, promotes the design of high energy density batteries, and improves the wetting ability of the electrolyte and the space utilization of the electrode.
Smart Images
Figure CN223487070U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of battery technology, specifically relating to a membrane preparation device. Background Technology
[0002] To achieve higher energy density, lithium-ion batteries using graphite or silicon-carbon anodes require a continuous increase in the loading of active materials in the battery electrodes, resulting in a continuous increase in electrode thickness. This, in turn, leads to a longer electrolyte wetting time and a decrease in battery rate performance. Utility Model Content
[0003] In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide a membrane preparation apparatus.
[0004] A first aspect of this utility model provides a membrane preparation apparatus, comprising: a freezing chamber, wherein at least two freezing sources are disposed in the freezing chamber, the at least two freezing sources are disposed vertically spaced apart, a freezing gap is formed between the vertically spaced freezing sources, the freezing gap is used to accommodate a membrane to be processed, and the temperature of the lower freezing source is lower than the temperature of the upper freezing source;
[0005] A drying chamber is used to at least sublimate and dry the membrane after it has been frozen in the freezing chamber, so as to form pores in the membrane.
[0006] The membrane preparation apparatus provided in this application embodiment has a simple structure and low cost. It can form an oriented pore structure perpendicular to the membrane direction. This pore structure can serve as a channel for rapid ion transport in the electrolyte, promoting electrolyte wetting. It also reduces the internal resistance of exciton transport inside the electrode, improves the rate performance of the battery, and promotes the design of high energy density batteries.
[0007] In addition, the exhaust valve of this utility model may also have the following additional technical features:
[0008] Preferably, the upper freezing source has a temperature of 0°C to -40°C and adopts a single-stage refrigeration structure that undergoes one evaporation and condensation process; the lower freezing source has a temperature of -30°C to -196°C and adopts a cascaded multi-stage refrigeration structure formed by a combination of multiple refrigeration cycles.
[0009] Preferably, the freezing source includes a cooling plate having a cooling plane that covers at least the area where the membrane is located along the width direction of the membrane.
[0010] Preferably, the refrigeration plate includes an evaporator, the evaporator is provided with a protective cover, the protective cover has a refrigeration plane on the side away from the evaporator, and the refrigeration plane is disposed close to the freezing gap.
[0011] Preferably, the upper refrigeration plate and the lower refrigeration plate have a first state of being close to each other and a second state of being far apart from each other. In the first state, the freezing gap is formed between the upper refrigeration plate and the lower refrigeration plate.
[0012] Preferably, each of the refrigeration plates is connected to a lifter, which is used to drive the refrigeration plate to move linearly along a side close to or away from the freezing gap.
[0013] Preferably, the drying chamber is provided with an air outlet, which has an air outlet facing the surface of the membrane. The air outlet is used to blow dry air at -30°C to 25°C onto the surface of the membrane.
[0014] Preferably, the air outlet device includes a blower nozzle and a fan. The blower nozzle is disposed inside the drying chamber, and the fan is disposed outside the drying chamber. The fan and the blower nozzle are connected and disposed in communication. The blower nozzle extends along the length direction of the diaphragm, and a plurality of air outlets are disposed inside the blower nozzle along the length direction of the diaphragm.
[0015] Preferably, at least one side wall of the freezing compartment and / or the drying compartment is provided with an insulation layer.
[0016] Preferably, the membrane preparation apparatus includes a box, and a partition is provided inside the box to divide the space inside the box into a freezing chamber and a drying chamber.
[0017] Preferably, the freezing chamber has a feed inlet on the side wall away from the drying chamber, and the drying chamber has a discharge outlet on the side wall away from the freezing chamber. The partition has a through hole, and the feed inlet, the through hole, and the discharge outlet cooperate to form a transmission channel for the membrane to be transported.
[0018] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description
[0019] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:
[0020] Figure 1 An exemplary structural diagram of the membrane fabrication apparatus provided in the embodiments of this application;
[0021] Figure 2 Another exemplary structural diagram of the membrane preparation apparatus provided in the embodiments of this application.
[0022] In the above image:
[0023] 100 Freezer compartment; 101 Feed inlet; 110 Refrigeration plate; 120 Lifter; 130 First refrigeration source; 131 Second refrigeration source;
[0024] 200 Drying chamber; 201 Discharge port; 210 Air outlet; 211 Air nozzle; 212 Fan; 213 Air outlet;
[0025] 300 Enclosure; 310 Partition; 311 Through-hole;
[0026] 400 Diaphragm; 401 Current collector; 402 Slurry;
[0027] 500 Feeding mechanism; 600 Unwinding mechanism; 700 Rewinding mechanism. Detailed Implementation
[0028] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the relevant utility model and not intended to limit the scope of the utility model. Furthermore, it should be noted that, for ease of description, only the parts relevant to the utility model are shown in the accompanying drawings.
[0029] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.
[0030] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” as used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.
[0031] Unless the context otherwise requires, throughout the specification and claims, the term "comprising" is interpreted as open and encompassing, that is, "including, but not limited to".
[0032] In the description of this specification, the terms "one embodiment," "some embodiments," "exemplary embodiment," "example," "specific example," or "some examples," etc., are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of this disclosure. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics mentioned may be included in any suitable manner in any one or more embodiments or examples.
[0033] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of this disclosure, unless otherwise stated, "a plurality of" means two or more.
[0034] like Figure 1 and Figure 2 As shown, in a first aspect, this utility model provides a membrane preparation apparatus, comprising: a freezing chamber 100, wherein at least two freezing sources are disposed in the freezing chamber 100, the at least two freezing sources are disposed vertically spaced apart, and a freezing gap is formed between the vertically spaced freezing sources, the freezing gap being used to accommodate a membrane 400 to be processed, and the temperature of the freezing source located below is lower than the temperature of the freezing source located above.
[0035] The drying chamber 200 is used to perform at least sublimation drying on the membrane 400 after it has been frozen in the freezing chamber 100, so as to form pores in the membrane 400.
[0036] The membrane 400 to be processed can be an electrode, such as a positive electrode or a negative electrode. The electrode is a current collector 401 coated with undried slurry 402. For example, a current collector 401 coated with positive electrode slurry 402 is a positive electrode, and a current collector 401 coated with negative electrode slurry 402 is a negative electrode. The membrane 400 can also be formed by covering other substrates with a viscous liquid mixture. Those skilled in the art can select the specific type of membrane 400 to be processed according to actual needs. This application embodiment uses an electrode formed by a current collector 401 coated with slurry 402 as an example to illustrate the specific implementation of the membrane preparation apparatus provided in this application embodiment.
[0037] The freezer compartment 100 is provided with at least two freezer sources. The multiple freezer sources can be divided into a first part of freezer sources and a second part of freezer sources. The first part of freezer sources are arranged in a direction parallel to the collector 401, and the second part of freezer sources are arranged in a direction parallel to the collector 401. The first part of freezer sources and the second part of freezer sources are arranged vertically at intervals. For example, the number of freezing sources can be 2, 4, 6, etc., where the two freezing sources are a first freezing source 130 and a second freezing source 131, which are arranged vertically at intervals. The first freezing source 130 is located above the second freezing source 131, that is, the first freezing source 130 is arranged near the slurry 402 side of the electrode, and the second freezing source 131 is arranged near the current collector 401 side of the electrode. A freezing gap is formed between the first freezing source 130 and the second freezing source 131, which can accommodate the current collector 401 coated with slurry 402. The temperature of the first freezing source 130 is higher than the temperature of the second freezing source 131, so that a temperature gradient from low to high is formed in the freezing chamber 100 from the second freezing source 131 to the first freezing source 130 (that is, the direction perpendicular to the current collector 401). This temperature gradient makes the temperature of the slurry 402 near the current collector 401 lower than the temperature of the slurry 402 away from the current collector 401. The lower the temperature, the smaller the ice crystal particles formed by the solvent in slurry 402. The ice crystals grow towards areas with higher temperatures, and the temperature gradient from low to high induces the growth direction and size of the ice crystals.
[0038] Therefore, within the temperature gradient provided by the freezing chamber 100, the solvent in the slurry 402 grows from the side of the current collector 401 towards the side away from the current collector 401 under the induction of the temperature gradient, until ice crystals grow to the top, and the insoluble particles in the slurry 402 are pushed away by the ice crystals, forming a solid structure on the current collector 401 where insoluble particles and ice crystals alternate. Furthermore, the solvent in the slurry 402 closer to the current collector 401 forms a large number of nucleated ice crystals, while the solvent in the slurry 402 further away from the current collector 401 forms fewer nucleated ice crystals, resulting in larger ice crystals.
[0039] The drying chamber 200 performs sublimation drying on the electrode sheet frozen in the freezing chamber 100. Sublimation drying refers to the phase change process in which a substance changes directly from a solid state to a gaseous state. In this example, the solid ice crystal structure formed by the solvent in the slurry 402 directly sublimates into a gaseous state in the drying chamber 200. The surface tension generated by the sublimation of the ice crystals on the insoluble particles is small, so the three-dimensional spatial structure occupied by the ice crystal growth is completely preserved. This allows the slurry 402 to form a porous structure at the ice crystal location. This porous structure is perpendicular to the current collector 401, and the pores closer to the current collector 401 have small pore diameters, while the pores farther from the current collector 401 have large pore diameters, similar to a trumpet-shaped structure. This improves the electrolyte wetting and battery rate problems caused by the increased thickness of the electrode sheet.
[0040] The membrane preparation apparatus provided in this application embodiment has a simple structure. By combining the temperature gradient provided by the freezing chamber 100 and the sublimation drying treatment of the drying chamber 200, the slurry 402 on the electrode can form an oriented pore structure perpendicular to the current collector 401. This pore structure can serve as a channel for rapid transport of electrolyte ions, promoting electrolyte wetting; and it also reduces the internal resistance of exciton transport inside the electrode, improving the rate performance of the battery and promoting the design of high energy density batteries, such as the structural design of lithium-ion batteries.
[0041] The pores formed in the slurry 402 on the electrode near the current collector 401 have small pore sizes, while those far from the current collector 401 have large pore sizes. The closer to the current collector 401, the lower the ion flow rate, and the smaller the required pore size, which can increase space utilization. Furthermore, the smaller the pore size near the current collector 401, the higher the electronic conductivity, thus guiding lithium ions to preferentially deposit near the current collector 401. This avoids lithium ions preferentially depositing on the surface far from the current collector 401, which would lead to the formation of a large number of surface lithium dendrites after fewer battery cycles, thereby improving the battery's energy density and cycle life.
[0042] In some embodiments, the upper freezing source has a temperature of 0°C to -40°C and employs a single-stage refrigeration structure that undergoes one evaporation and condensation process; the lower freezing source has a temperature of -30°C to -196°C and employs a cascaded multi-stage refrigeration structure formed by a combination of multiple refrigeration cycles.
[0043] Specifically, the temperature of the first freezing source 130 is any temperature value between 0℃ and -40℃, such as 0℃, -10℃, -15℃, -20℃, -25℃, -30℃, -35℃, -40℃, or any range of the above values. The temperature of the second freezing source 131 is any temperature value between -30℃ and -196℃, such as -30℃, -50℃, -80℃, -100℃, -120℃, -140℃, -160℃, -180℃, -190℃, or any range of the above values.
[0044] For example, such as Figure 2 As shown, the first refrigeration source 130 adopts a single-stage refrigeration structure with one evaporation and condensation process. It has a refrigeration system with only one refrigeration unit, which mainly includes a compressor, condenser, capillary tube and evaporator. The compressor compresses the low-temperature and low-pressure gas into a high-temperature and high-pressure gas. The condenser turns the high-temperature and high-pressure gas discharged from the compressor into a low-temperature and high-pressure liquid. The capillary tube turns the low-temperature and high-pressure liquid discharged from the condenser into a low-temperature and low-pressure liquid. The low-temperature and low-pressure liquid enters the evaporator. The low-temperature and low-pressure liquid evaporates and absorbs heat, which lowers the surface temperature of the evaporator and thus lowers the temperature inside the freezer compartment.
[0045] For example, such as Figure 2 As shown, the second refrigeration source 131 employs a cascaded multi-stage refrigeration structure formed by combining multiple refrigeration cycles. This refrigeration system, composed of two or more refrigeration units, achieves a more efficient refrigeration process through the cooperation of multiple compressors, capillary tubes, condensers, and evaporators, reaching a lower evaporation temperature than a single-stage refrigeration cycle. For example, taking a two-stage cascaded multi-stage refrigeration structure, it consists of a high-temperature stage and a low-temperature stage. The high-temperature stage uses a medium-temperature refrigerant, and the low-temperature stage uses a low-temperature refrigerant, forming a cycle of two single-stage compression refrigeration units working in cascade. The refrigerant in the high-temperature stage evaporates in the evaporator, absorbing heat from the low-temperature stage refrigerant and condensing it. The refrigerant vapor in the high-temperature stage transfers heat to the surrounding medium, completing one refrigeration cycle. The refrigerant in the low-temperature stage, after being depressurized through a capillary tube, enters the evaporator, absorbing heat from the object being cooled and evaporating to achieve the desired low temperature.
[0046] The temperature of the first freezing source 130 is higher than that of the second freezing source 131, so that a temperature gradient is formed in the freezing chamber 100 along the direction perpendicular to the current collector 401, and the temperature of the electrode near the slurry 402 is close to that of the current collector 401. By controlling the freezing temperature and freezing rate in the freezing chamber 100, the orientation and size of the solvent crystals in the slurry 402 on the electrode can be controlled, so that an oriented crystalline structure is formed in the slurry 402. The crystals grow from the side near the current collector 401 to the side away from the current collector 401, thereby forming an oriented porous structure in the slurry 402 on the electrode, improving the wetting ability of the electrolyte and the rate performance of the battery.
[0047] In some implementations, such as Figure 1 As shown, the freezing source includes a cooling plate 110, which has a cooling plane that covers at least the area where the diaphragm 400 is located along the width direction of the diaphragm 400.
[0048] Specifically, both the first freezing source 130 and the second freezing source 131 include a cooling plate 110. The cooling plate 110 has a cooling plane that covers at least the area where the slurry 402 is located on the electrode along the width direction of the electrode, so that the cooling temperature of the slurry 402 at each location is uniform, thereby forming a coating of uniform thickness on the surface of the current collector 401. The width direction of the electrode is perpendicular to the running direction of the electrode. By controlling the temperature of the upper and lower cooling plates 110, a temperature gradient with increasing temperature from bottom to top can be formed inside the freezing chamber 100.
[0049] In some embodiments, the refrigeration plate 110 includes an evaporator, the evaporator is provided with a protective cover, the side of the protective cover away from the evaporator has the refrigeration plane, and the refrigeration plane is disposed close to the freezing gap.
[0050] Specifically, the evaporator utilizes the low-temperature, low-pressure liquid refrigerant to vaporize and absorb heat on one side of the evaporator's heat transfer wall, thereby cooling the medium on the other side of the heat transfer wall. Water or air is typically used as the cooling medium, and the refrigeration effect is achieved through heat exchange with the outside air. A protective cover with a refrigeration plane is installed on the side of the evaporator near the freezing gap, allowing for the freezing of the collector 401 coated with slurry 402 within the freezing gap.
[0051] In some embodiments, the upper refrigeration plate 110 and the lower refrigeration plate 110 have a first state of being close to each other and a second state of being far apart from each other. In the first state, the freezing gap is formed between the upper refrigeration plate 110 and the lower refrigeration plate 110.
[0052] Specifically, such as Figure 1 As shown, in the first state, a freezing gap is formed between the upper and lower cooling plates 110 to accommodate the electrode, allowing the upper and lower cooling plates 110 to be positioned close to the electrode. This enables more precise control of the electrode's cooling temperature, which in turn facilitates the formation of an oriented crystalline structure in the solvent within the slurry 402 on the electrode, and allows for precise crystal size determination. In the second state, the upper and lower cooling plates 110 are positioned further apart, facilitating the installation and transfer of the electrode within the freezing chamber 100.
[0053] In some implementations, such as Figure 1 As shown, each of the refrigeration plates 110 is connected to a lifter 120, which is used to drive the refrigeration plate 110 to move linearly along a side close to or away from the freezing gap.
[0054] Specifically, the upper and lower cooling plates 110 are each connected to a lifter 120. The electrode plates housed in the freezing gap are controlled by the lifter 120 to move towards or away from the electrode plates. When the upper and lower electrode plates move towards each other, the electrode plates can be uniformly frozen. When the upper and lower electrode plates move away from each other, it facilitates the installation and transfer of the electrode plates within the freezing chamber 100. Furthermore, the width of the freezing gap can be controlled by the lifter 120, thereby controlling the magnitude of the temperature gradient and adjusting the pore structure gradient of the electrode plates to a suitable size.
[0055] In some implementations, such as Figure 1As shown, the drying chamber 200 is provided with an air outlet 210, which has an air outlet 213 facing the surface of the diaphragm 400. The air outlet 213 is used to blow dry air at -30°C to 25°C onto the surface of the diaphragm 400.
[0056] Specifically, the air outlet 210 can be installed inside or outside the drying chamber 200. The air outlet 210 has an air outlet 213 located inside the drying chamber 200 and facing the slurry 402 side of the electrode. It can blow dry air at -30℃ to 25℃ towards the slurry 402 side. Temperatures below -30℃ are not conducive to the crystallization and sublimation of the slurry 402; temperatures above 25℃ can easily lead to the melting of the crystals. For example, the drying temperature can be -30℃, -20℃, -10℃, 0℃, 10℃, 20℃, or any range of these values. Preferably, the freeze-dried electrode is processed using convection drying within the drying chamber 200, which allows the crystals in the slurry 402 to directly sublimate from solid to gas to form an oriented porous structure. The dry air carries away the sublimated water vapor.
[0057] It should be noted that a temperature sensor can be installed inside the drying chamber 200. The temperature sensor is placed close to the electrode, and the drying temperature of the electrode can be accurately detected through the temperature sensor, thereby allowing for precise control of the drying temperature of the electrode.
[0058] In some implementations, such as Figure 2 As shown, the air outlet device 210 includes a blower nozzle 211 and a fan 212. The blower nozzle 211 is disposed inside the drying chamber 200, and the fan 212 is disposed outside the drying chamber 200. The fan 212 is connected to the blower nozzle 211, and the blower nozzle 211 extends along the length direction of the diaphragm 400. A plurality of air outlets 213 are disposed inside the blower nozzle 211 along the length direction of the diaphragm 400.
[0059] Specifically, the air nozzle 211 extends along the running direction of the electrode sheet within the drying chamber 200. The air nozzle 211 is connected to a fan 212 located outside the drying chamber 200 via a pipe. The air nozzle 211 has multiple air outlets 213. The fan 212 blows dry air onto the slurry 402 of the electrode sheet through the air nozzle 211, causing the crystals within the slurry 402 to sublimate and form a porous structure. The multiple air outlets 213 distributed along the running direction of the electrode sheet ensure uniform drying of the slurry 402 and the formation of a uniform coating on the surface of the current collector 401.
[0060] In some embodiments, at least one side wall of the freezing chamber 100 and / or the drying chamber 200 is provided with an insulation layer.
[0061] Specifically, at least one of the front, rear, left, and right side walls of the freezer compartment 100 is provided with an insulation layer. The insulation layer can reduce heat loss from the freezer compartment 100 and reduce energy consumption. Or / and, at least one of the front, rear, left, and right side walls of the drying compartment 200 is provided with an insulation layer, which can also reduce heat loss and further reduce energy consumption.
[0062] In some implementations, such as Figure 1 and Figure 2 As shown, the membrane preparation device includes a box 300, and a partition 310 is provided inside the box 300. The partition 310 divides the space inside the box 300 into the freezing chamber 100 and the drying chamber 200.
[0063] Specifically, a partition 310 is installed inside the cabinet 300, which divides the space inside the cabinet 300 into a freezer compartment 100 and a dryer compartment 200, so that the freezer compartment 100 and the dryer compartment 200 share the same partition 310 as the compartment wall, thus saving costs.
[0064] In some implementations, such as Figure 1 and Figure 2 As shown, the freezing chamber 100 has an inlet 101 on the side wall away from the drying chamber 200, and the drying chamber 200 has an outlet 201 on the side wall away from the freezing chamber 100. The partition 310 has a through hole 311. The inlet 101, the through hole 311 and the outlet 201 cooperate to form a transmission channel for the membrane 400 to transmit.
[0065] Specifically, the box 300 has an inlet 101 and an outlet 201 on its two side walls along its length. The inlet 101 is located on the side wall of the freezing chamber 100, and the outlet 201 is located on the side wall of the drying chamber 200. The partition 310 has a through hole 311, so that the current collector 401 coated with slurry 402 passes through the inlet 101, the through hole 311 and the outlet 201 in sequence. That is, the current collector 401 coated with slurry 402 first undergoes freezing treatment in the freezing chamber 100 and then sublimation drying treatment in the drying chamber 200, realizing continuous processing of the electrode.
[0066] It should be noted that if Figure 1 and Figure 2As shown, a feeding mechanism 500 is also provided on the outside of the feed inlet 101 side of the housing 300. The feeding mechanism 500 includes any one of a slit coating die, a micro-gravure roller, an ultrasonic spraying device, and an anilox roller to apply slurry 402 to the current collector 401. The current collector 401 coated with slurry 402 is first sent to the freezing chamber 100 for freezing treatment, and then sent to the drying chamber 200 for drying treatment to obtain an electrode with an oriented pore structure. When using this electrode to prepare a battery, the electrolyte can quickly wet the electrode along the pores and reduce ion transport obstruction, thereby improving the battery rate performance.
[0067] It is understandable that, such as Figure 1 and Figure 2 As shown, a winding mechanism 700 and an unwinding mechanism 600 can also be provided on the outer sides of both sides of the housing 300 along the length direction. The unwinding mechanism 600 is located near the feed inlet 101 (the feeding mechanism 500 is located between the unwinding mechanism 600 and the feed inlet 101), and the winding mechanism 700 is located near the discharge outlet 201. The winding mechanism 700 and the unwinding mechanism 600 are conventional structures in the art, and will not be described in detail in this application embodiment. Through the cooperation of the unwinding mechanism 600 and the winding mechanism 700, the automatic unwinding and winding operation of the electrode sheet can be realized, thereby realizing the continuous processing operation of the electrode sheet.
[0068] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the utility model involved in this application is not limited to the technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.
Claims
1. A membrane preparation apparatus, characterized in that, include: A freezing chamber (100) is provided with at least two freezing sources, which are arranged vertically at intervals, forming a freezing gap between them. The freezing gap is used to accommodate the film (400) to be processed, and the temperature of the freezing source located below is lower than the temperature of the freezing source located above. A drying chamber (200) is used to at least sublimate and dry the membrane (400) after it has been frozen in the freezing chamber (100) so that pores are formed inside the membrane (400).
2. The membrane preparation apparatus according to claim 1, characterized in that, The upper freezing source has a temperature of 0℃ to -40℃ and adopts a single-stage refrigeration structure that undergoes one evaporation and condensation process; the lower freezing source has a temperature of -30℃ to -196℃ and adopts a cascaded multi-stage refrigeration structure formed by the combination of multiple refrigeration cycles.
3. The membrane preparation apparatus according to claim 1, characterized in that, The freezing source includes a cooling plate (110) having a cooling plane that covers at least the area where the membrane (400) is located along the width direction of the membrane (400).
4. The membrane preparation apparatus according to claim 3, characterized in that, The refrigeration plate (110) includes an evaporator, and a protective cover is provided on the evaporator. The side of the protective cover away from the evaporator has the refrigeration plane, and the refrigeration plane is located close to the freezing gap.
5. The membrane preparation apparatus according to claim 3, characterized in that, The upper refrigeration plate (110) and the lower refrigeration plate (110) have a first state of being close to each other and a second state of being far apart from each other. In the first state, the freezing gap is formed between the upper refrigeration plate (110) and the lower refrigeration plate (110).
6. The membrane preparation apparatus according to any one of claims 3-5, characterized in that, Each of the refrigeration plates (110) is connected to a lifter (120), which is used to drive the refrigeration plate (110) to move linearly along a side close to or away from the refrigeration gap.
7. The membrane preparation apparatus according to claim 1, characterized in that, The drying chamber (200) is provided with an air outlet (210), which has an air outlet (213) facing the surface of the diaphragm (400). The air outlet (213) is used to blow dry air at -30°C to 25°C onto the surface of the diaphragm (400).
8. The membrane preparation apparatus according to claim 7, characterized in that, The air outlet device (210) includes a blower nozzle (211) and a fan (212). The blower nozzle (211) is disposed inside the drying chamber (200), and the fan (212) is disposed outside the drying chamber (200). The fan (212) is connected to the blower nozzle (211), and the blower nozzle (211) extends along the length direction of the diaphragm (400). Multiple air outlets (213) are disposed inside the blower nozzle (211) along the length direction of the diaphragm (400).
9. The membrane preparation apparatus according to any one of claims 1-5, characterized in that, An insulation layer is provided on at least one side wall of the freezing chamber (100) and / or the drying chamber (200).
10. The membrane preparation apparatus according to any one of claims 1-5, characterized in that, The membrane preparation device includes a box (300), and a partition (310) is provided inside the box (300). The partition (310) divides the space inside the box (300) into the freezing chamber (100) and the drying chamber (200).
11. The membrane preparation apparatus according to claim 10, characterized in that, The freezing chamber (100) has an inlet (101) on the side wall away from the drying chamber (200), and the drying chamber (200) has an outlet (201) on the side wall away from the freezing chamber (100). The partition (310) has a through hole (311). The inlet (101), the through hole (311) and the outlet (201) cooperate to form a transmission channel for the membrane (400) to be transmitted.