Diaphragm preparation process with dispersed ceramic powder and base membrane, ceramic diaphragm and equipment thereof

Abstract

The invention provides a ceramic powder and base membrane dispersed diaphragm preparation process, a ceramic diaphragm and equipment thereof. The preparation process of the diaphragm with dispersed ceramic powder and base membrane comprises the following steps: obtaining the ceramic powder; introducing an air source into the ceramic powder, wherein the flow velocity of the air source is 80 sccm to 100 sccm; the gas source is subjected to plasma treatment, modified ceramic powder is obtained, the plasma power source power ranges from 400 W to 800 W, the discharge voltage ranges from 700 V to 1000 V, the discharge current ranges from 0.5 A to 3 A, and the temperature ranges from 80 DEG C to 150 DEG C; an adhesive, a dispersing agent and the modified ceramic powder are mixed in a solvent to obtain modified ceramic powder coating slurry, and the ratio of the adhesive to the modified ceramic powder to the dispersing agent is 5: (93-94): (1-2); and coating a base membrane with the modified ceramic powder coating slurry to obtain the modified ceramic powder composite diaphragm.

Description

Technical Field

[0001] The present disclosure relates to the field of lithium batteries, and particularly to a preparation process of a separator with ceramic powder and base film dispersion, a ceramic separator and its equipment. Background Art

[0002] The separator is one of the four main materials of lithium-ion batteries. The quality of the separator performance is crucial for the charging and discharging, light weight and safety of lithium-ion batteries. Currently, the widely used polyolefin separators and ceramic composite separators in the market have their own advantages and disadvantages. Traditional polyolefin separators have advantages such as high mechanical strength and good electrochemical stability, but they have defects such as poor electrolyte wettability, high interfacial resistance, poor thermal stability, and easy shrinkage when heated, which is not conducive to the use of batteries in harsh environments; ceramic composite separators have extremely high thermal stability and chemical stability, and at the same time have stronger wettability and liquid retention ability for electrolytes, which can improve the electrochemical performance, safety and service life of batteries. However, when ceramic particles are coated on the surface of the separator, problems such as particle agglomeration and uneven dispersion, ceramic particle shedding after coating resulting in pore blockage, and easy moisture absorption of ceramic composite separators will occur, which have an adverse impact on the cycle performance and service life of the batteries.

[0003] In order to achieve better dispersion effect of ceramic powder, Chinese Patent with publication number CN104538576B discloses a modified ceramic separator for lithium-ion batteries and its preparation method. It modifies the surface of ceramic powder through alkyl anionic surfactants, vinyl or amino silane coupling agents, and at the same time performs plasma treatment on the polyolefin base film to reduce powder agglomeration and improve dispersibility and compatibility. However, using surfactants to modify ceramic powder has a complex process and high energy consumption, and organic solvents or acid-base solutions will produce a large amount of waste liquid, resulting in environmental pollution. At the same time, surface modification at the atomic scale of the powder cannot be achieved, that is, the dispersibility and compatibility of ceramic powder are not high enough.

[0004] Therefore, there is an urgent need for a ceramic powder modification process and equipment that can make the dispersibility and compatibility of ceramic powder higher, be environmentally friendly and have higher production efficiency. Summary of the Invention

[0005] The purpose of the present disclosure is to overcome the deficiencies in the prior art and provide a preparation process of a separator with ceramic powder and base film dispersion, a ceramic separator and its equipment that can make the dispersibility and compatibility of ceramic powder higher, be environmentally friendly and have higher production efficiency.

[0006] The purpose of the present disclosure is achieved through the following technical solutions: A preparation process of a separator with ceramic powder and base film dispersion, comprising: Obtaining ceramic powder; Introduce a gas source to the ceramic powder to fluidize the ceramic powder, so that the gas source is mixed with the ceramic powder. The flow rate of the gas source is 80 sccm - 100 sccm; Perform plasma treatment on the gas source to form a plasma from the gas source, and make the plasma impact the surface of the ceramic powder to obtain a modified ceramic powder. Among them, the plasma power supply power is 400 W - 800 W, the discharge voltage is 700 V - 1000 V, the discharge current is 0.5 A - 3 A, and the temperature is 80 °C - 150 °C; Mix the binder, dispersant and the modified ceramic powder in a solvent to obtain a modified ceramic powder coating slurry. The ratio of the binder, the modified ceramic powder and the dispersant is 5:93 - 94:1 - 2; Coat the modified ceramic powder coating slurry on a base film to obtain a modified ceramic powder composite separator.

[0007] In one embodiment, introduce a gas source to the ceramic powder to fluidize the ceramic powder, so that the gas source is mixed with the ceramic powder. Specifically, it includes the following steps: Introduce a first gas source to the ceramic powder; Introduce a second gas source to the ceramic powder to mix the first gas source with the second gas source. Among them, the mixing ratio of the first gas source and the second gas source is 1:2 - 3.

[0008] In one embodiment, the first gas source is one of nitrogen, helium, argon, oxygen, ammonia, methane and air.

[0009] In one embodiment, the second gas source is one of nitrogen, helium, argon, oxygen, ammonia, methane and air.

[0010] In one embodiment, the dispersant is polyvinylpyrrolidone.

[0011] In one embodiment, the solvent is one of N-methylpyrrolidone or water.

[0012] In one embodiment, the binder is one of polyvinylidene fluoride, sodium carboxymethyl cellulose and styrene-butadiene rubber.

[0013] In one embodiment, the base film is one of polypropylene or polyethylene.

[0014] A ceramic separator manufacturing device includes: A reaction chamber; Feeding mechanism, the feeding mechanism includes a feed bin and a discharge bin, the feed bin and the discharge bin are respectively communicated with the reaction bin, the feed bin is used for conveying the ceramic powder into the reaction bin, and the discharge bin is used for collecting and outputting the ceramic powder in the reaction bin; Gas source mechanism, the gas source mechanism is communicated with the reaction bin, and the gas source mechanism is used for conveying the gas source into the reaction bin; Plasma reaction mechanism, the plasma reaction mechanism is communicated with the reaction bin, the acting end of the plasma reaction mechanism is located in the reaction bin, and the plasma reaction mechanism is used for plasmaizing the gas source; Controller, the controller is electrically connected to the gas source mechanism and the plasma reaction mechanism respectively, so that the gas source mechanism fluidizes the ceramic powder in the reaction bin, and the plasma reaction mechanism plasmaizes the gas source in the reaction bin.

[0015] A ceramic diaphragm is prepared by using the ceramic diaphragm manufacturing equipment described in any one of the above embodiments.

[0016] Compared with the prior art, the present disclosure has at least the following advantages: 1. In the above-mentioned diaphragm preparation process of dispersing ceramic powder and base film, a gas source is introduced into the ceramic powder for fluidization treatment, and the flow rate of the gas source is 80 sccm - 100 sccm, so that the ceramic powder is in a suspended state to reduce the agglomeration between the ceramic powders, and at the same time, the gas source and the ceramic powder are fully mixed. Then, the gas source is subjected to plasma treatment, wherein the plasma power is 400 W - 800 W, the discharge voltage is 700 V - 1000 V, the discharge current is 0.5 A - 3 A, and the temperature is 80 °C - 150 °C, so that the gas source forms plasma, and the plasma impacts the surface of the ceramic powder, causing many defects and active sites on the surface of the ceramic powder, thereby modifying the ceramic powder. The existence of these defects and active sites enables the ceramic powder to chemically adsorb with the base film to form a cross-linked structure, and also improves the dispersibility and compatibility of the ceramic powder on the base film, so that the ceramic powder can be evenly coated on the surface of the base film. Compared with the traditional technology of using surfactants to modify ceramic powder, the solution of the present application is simple to operate, environmentally friendly and has high production efficiency. At the same time, it also realizes the surface modification of ceramic powder at the atomic scale to better improve the dispersibility and compatibility of ceramic powder on the base film.

[0017] 2. The defects and active sites on the surface of the modified ceramic powder are chemically adsorbed with the base film to form a cross-linked structure. The cross-linked structure makes the structure of the separator more stable, thereby improving the problem that the ceramic powder falls off after the separator is soaked in the electrolyte for a long time, that is, improving the structural stability of the separator. At the same time, plasma modification can also generate hydrophilic groups on the surface of the ceramic powder, such as carbonyl groups, hydroxyl groups, etc., thereby improving the wetting ability of the electrolyte to the separator, reducing the internal resistance of the battery, and enabling the battery to have a better capacity retention rate.

[0018] 3. Since the shape retention ability of the ceramic powder is much greater than that of the base film, the presence of the ceramic powder hinders the thermal shrinkage of the separator, improves the thermal deformation resistance of the separator, and thus improves the performance of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present disclosure, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0020] Figure 1 It is a process flow diagram of a preparation process of a separator in which ceramic powder and a base film are dispersed in an embodiment; Figure 2 It is a structural schematic diagram of a ceramic separator manufacturing device in an embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] To facilitate the understanding of the present disclosure, the present disclosure will be described more comprehensively below with reference to the relevant drawings. The preferred embodiments of the present disclosure are shown in the drawings. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present disclosure more thorough and comprehensive.

[0022] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are only for the purpose of illustration and do not represent the only embodiments.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this disclosure belongs. The terms used in the description of this disclosure herein are for the purpose of describing specific embodiments only and are not intended to limit this disclosure. The term "and / or" as used herein includes any and all combinations of one or more of the related listed items.

[0024] This disclosure provides a process for preparing a separator with ceramic powder and base film dispersion, including the following steps: obtaining ceramic powder; introducing a gas source to the ceramic powder to fluidize the ceramic powder so that the gas source is mixed with the ceramic powder, and the flow rate of the gas source is 80 sccm - 100 sccm; performing plasma treatment on the gas source to form a plasma and making the plasma impact the surface of the ceramic powder to obtain modified ceramic powder, wherein the plasma power supply power is 400 W - 800 W, the discharge voltage is 700 V - 1000 V, the discharge current is 0.5 A - 3 A, and the temperature is 80 °C - 150 °C; mixing a binder, a dispersant and the modified ceramic powder in a solvent to obtain a modified ceramic powder coating slurry, and the ratio of the binder, the modified ceramic powder and the dispersant is 5:93 - 94:1 - 2; coating the modified ceramic powder coating slurry on a base film to obtain a modified ceramic powder composite separator; wherein, introducing a gas source to the ceramic powder to fluidize the ceramic powder so that the gas source is mixed with the ceramic powder specifically includes the following steps: introducing a first gas source to the ceramic powder to impact the surface of the ceramic powder; introducing a second gas source to the ceramic powder to impact the surface of the ceramic powder; and obtaining the gas type of the second gas source; performing a gas type product process on the gas type and a preset type to obtain a gas source gas reaction product; detecting whether the gas source gas reaction product is greater than or equal to a preset reaction product; when the gas source gas reaction product is greater than or equal to the preset reaction product, introducing the first gas source and the second gas source in a time-sharing manner to perform primary plasma treatment and secondary plasma treatment.

[0025] For the diaphragm preparation process of dispersing the above-mentioned ceramic powder and base film, a gas source is introduced into the ceramic powder for fluidization treatment. The flow rate of the gas source is 80 sccm - 100 sccm, so that the ceramic powder is in a suspended state to reduce the agglomeration between the ceramic powders. At the same time, the gas source is fully mixed with the ceramic powder, and then the gas source is subjected to plasma treatment. Among them, the plasma power supply power is 400 W - 800 W, the discharge voltage is 700 V - 1000 V, the discharge current is 0.5 A - 3 A, and the temperature is 80 °C - 150 °C, so that the gas source forms a plasma, and the plasma impacts the surface of the ceramic powder, resulting in many defects and active sites on the surface of the ceramic powder, thereby modifying the ceramic powder. The existence of these defects and active sites enables the ceramic powder to chemically adsorb with the base film to form a cross-linked structure, and also improves the dispersibility and compatibility of the ceramic powder on the base film, so that the ceramic powder can be evenly coated on the surface of the base film. Compared with the traditional technology of using surfactants to modify ceramic powders, the solution of this application is simple to operate, environmentally friendly and has high production efficiency. At the same time, it also realizes the surface modification of ceramic powders at the atomic scale to better improve the dispersibility and compatibility of ceramic powders on the base film; the defects and active sites on the surface of the modified ceramic powder chemically adsorb with the base film to form a cross-linked structure, and the cross-linked structure makes the structure of the diaphragm more stable, thereby improving the problem that the ceramic powder falls off after the diaphragm is soaked in the electrolyte for a long time, that is, improving the structural stability of the diaphragm. At the same time, plasma modification can also generate hydrophilic groups on the surface of the ceramic powder, such as carbonyl groups, hydroxyl groups, etc., thereby improving the wetting ability of the electrolyte on the diaphragm, reducing the internal resistance of the battery, and enabling the battery to have a good capacity retention rate; because the shape retention ability of the ceramic powder is much greater than that of the base film, the presence of the ceramic powder hinders the thermal shrinkage of the diaphragm, improves the thermal deformation resistance of the diaphragm, and thus improves the performance of the battery.

[0026] To better understand the technical solutions and beneficial effects of the present disclosure, the following further elaborates on the present disclosure with specific embodiments: As Figure 1 shown, the diaphragm preparation process of dispersing ceramic powder and base film in an embodiment includes the following steps: S100: Obtain ceramic powder. It can be understood that the base film generally uses polyolefin materials, which have advantages such as high mechanical strength and good electrochemical stability. However, it has defects such as poor electrolyte wettability, high interfacial resistance, poor thermal stability, and easy shrinkage when heated. To solve the above problems, a layer of ceramic powder can be coated on the base film. The ceramic powder can improve the thermal stability of the base film, and at the same time make the base film have stronger wettability and liquid retention ability for the electrolyte, thereby improving the electrochemical performance of the battery. However, when ceramic particles are coated on the surface of the separator, problems such as particle agglomeration and uneven dispersion, particle shedding after coating resulting in pore blockage, and easy moisture absorption of the ceramic composite separator will occur. And the traditional technology of using surfactants to modify ceramic powder has problems such as complex process, high energy consumption, and a large amount of waste liquid generated, resulting in environmental pollution. Therefore, in this application, ceramic powder is used and the surface of the ceramic powder is modified at the atomic scale to improve the performance of the separator.

[0027] S200: Pass a gas source into the ceramic powder to fluidize the ceramic powder so that the gas source is mixed with the ceramic powder. The flow rate of the gas source is 80 sccm - 100 sccm. It can be understood that after placing the ceramic powder in the reaction chamber of the equipment, start the gas source mechanism to introduce the gas source into the reaction chamber. The flow rate of the gas source is 80 sccm - 100 sccm. The flow rate of the gas source is the fluidization flow rate of the ceramic powder to ensure that the ceramic powder is in a suspended state under the action of the gas source, which is the fluidization treatment of the ceramic powder. Under the action of the fluidization treatment, the ceramic powder vibrates violently, and adjacent ceramic powders collide and disperse, thus reducing the agglomeration of the ceramic powder and at the same time making the gas source and the ceramic powder fully mixed, and then making the effect of plasma treatment of the gas source and the ceramic powder better.

[0028] S300: Perform plasma treatment on the gas source to form a plasma of the gas source and make the plasma impact the surface of the ceramic powder to obtain modified ceramic powder, where the plasma power supply power is 400 W - 800 W, the discharge voltage is 700 V - 1000 V, the discharge current is 0.5 A - 3 A, and the temperature is 80 °C - 150 °C. It can be understood that after the gas source and the ceramic powder are fully mixed, the agglomeration between the ceramic powders is reduced at this time. Start the plasma equipment to perform plasma treatment on the gas source. Among them, the plasma power supply power is 400 W - 800 W, the discharge voltage is 700 V - 1000 V, the discharge current is 0.5 A - 3 A, and the temperature is 80 °C - 150 °C, so that the gas source forms a plasma, and the plasma impacts the surface of the ceramic powder, making many defects and active sites appear on the surface of the ceramic powder. These defects and active sites can cause chemical adsorption between the ceramic powder and the base film to form a cross-linked structure, so as to improve the dispersibility and compatibility of the ceramic powder on the base film, and then realize the modification of the ceramic powder, so that the ceramic powder can be evenly coated on the surface of the base film.

[0029] S400: Mix the binder, dispersant and the modified ceramic powder in a solvent to obtain a modified ceramic powder coating slurry. The ratio of the binder, the modified ceramic powder and the dispersant is 5:93 - 94:1 - 2. It can be understood that when the binder, dispersant and the modified ceramic powder are mixed in a solvent, the binder is mainly used to improve the bonding strength between the ceramic powder and the base film, so that the ceramic powder is firmly bonded to the surface of the base film. The dispersant is mainly used to reduce the attraction between the ceramic powders, prevent the aggregation of the ceramic powders, and make the ceramic powders evenly dispersed in the solvent to form a stable suspension, thereby avoiding the agglomeration and precipitation of the ceramic powders in the slurry.

[0030] S500: Coat the modified ceramic powder coating slurry on the base film to obtain a modified ceramic powder composite separator. It can be understood that the modified ceramic powder coating slurry is coated on the base film by a coater. Since the ceramic powder is treated by plasma with a gas source, many defects and active sites are generated on the surface of the ceramic powder, and then the ceramic powder is modified. The existence of these defects and active sites can enable the ceramic powder to chemically adsorb with the base film to form a cross-linked structure, improving the dispersibility and compatibility of the ceramic powder on the base film, so that the ceramic powder can be evenly coated on the surface of the base film.

[0031] Among them, a gas source is introduced into the ceramic powder to fluidize the ceramic powder so that the gas source is mixed with the ceramic powder, which specifically includes the following steps: Introduce a first gas source into the ceramic powder to impact the surface of the ceramic powder; Introduce a second gas source into the ceramic powder to impact the surface of the ceramic powder; And, Obtain the gas type of the second gas source; Perform a gas type product process on the gas type and a preset type to obtain a gas source gas reaction product; Detect whether the gas source gas reaction product is greater than or equal to a preset reaction product; When the gas source gas reaction product is greater than or equal to the preset reaction product, the first gas source and the second gas source are introduced in a time-sharing manner to perform primary plasma treatment and secondary plasma treatment.

[0032] It can be understood that in order to make the active sites and defects formed on the surface of the ceramic powder more complex and diversified, two gas sources can be used to bombard the ceramic powder. However, if both the first gas source and the second gas source introduced are relatively active gases, during the plasma treatment discharge, the first gas source and the second gas source will react, resulting in the internal consumption of the first gas source and the second gas source. As a result, the active sites and defects formed on the surface of the ceramic powder cannot achieve the expected effect. At the same time, when the first gas source and the second gas source discharge and react at a relatively high concentration, there is a certain risk, and even an explosion may occur. Therefore, in this embodiment, before introducing the second gas source, the gas type of the second gas source is detected first, and the gas type of the second gas source can be accurately detected by a gas detector to determine whether the second gas source and the first gas source can be introduced simultaneously.Further, after determining the gas type of the second gas source, perform a gas type multiplication process on the gas type of the second gas source and a preset type, where the preset type is the gas type of the first gas source. The specific operations of the gas type multiplication process and obtaining the reaction product of the gas sources are as follows: First, mark active gases and inert gases in advance. For example, inert gases (such as helium, argon, etc.) are marked as "1", and active gases (such as oxygen, ammonia, methane, etc.) are marked as "2", and the preset reaction product can be set as "3". The reaction product of the first gas source and the second gas source is used to reflect the reaction intensity between the two gas sources. Specifically, there are the following four situations: 1. When the first gas source is an inert gas and the second gas source is also an inert gas, the reaction product of the gas sources is multiplied to get "1" at this time. At this time, the reaction product "1" is less than the preset reaction product "3", indicating that the first gas source and the second gas source will not react under the discharge condition and can be introduced simultaneously; 2. When the first gas source is an inert gas and the second gas source is an active gas, the reaction product of the gas sources is multiplied to get "2" at this time. At this time, the reaction product "2" is less than the preset reaction product "3", indicating that the first gas source and the second gas source will not react under the discharge condition and can be introduced simultaneously; 3. When the first gas source is an active gas and the second gas source is an inert gas, the reaction product of the gas sources is multiplied to get "2" at this time. At this time, the reaction product "2" is less than the preset reaction product "3", indicating that the first gas source and the second gas source will not react under the discharge condition and can be introduced simultaneously; 4. When the first gas source is an active gas and the second gas source is also an active gas, the reaction product of the gas sources is multiplied to get "4" at this time. At this time, the reaction product "4" is greater than the preset reaction product "3", indicating that the first gas source and the second gas source will react under the discharge condition and the reaction is relatively intense. That is, the first gas source and the second gas source cannot be introduced simultaneously. At this time, the first gas source and the second gas source need to be introduced separately, and primary plasma treatment and secondary plasma treatment are carried out respectively. That is, after introducing the first gas source, primary plasma treatment is carried out to make the first gas source form a plasma to bombard the ceramic powder. After the first gas source is consumed, the second gas source is introduced, and then secondary plasma treatment is carried out to make the second gas source form a plasma to bombard the ceramic powder. In this way, while ensuring that the first gas source and the second gas source jointly modify the ceramic powder, it also avoids the internal consumption of the first gas source and the second gas source, reduces the production cost, and at the same time avoids the risk brought by the reaction of the first gas source and the second gas source under the discharge condition.

[0033] For the diaphragm preparation process of dispersing the above-mentioned ceramic powder and base film, a gas source is introduced into the ceramic powder for fluidization treatment. The flow rate of the gas source is 80 sccm - 100 sccm, so that the ceramic powder is in a suspended state to reduce the agglomeration between the ceramic powders and at the same time make the gas source and the ceramic powder fully mixed. Then, the gas source is subjected to plasma treatment. Among them, the plasma power supply power is 400 W - 800 W, the discharge voltage is 700 V - 1000 V, the discharge current is 0.5 A - 3 A, and the temperature is 80 °C - 150 °C, so that the gas source forms a plasma, and the plasma impacts the surface of the ceramic powder, causing many defects and active sites on the surface of the ceramic powder, thereby modifying the ceramic powder. The existence of these defects and active sites enables the ceramic powder to chemically adsorb with the base film to form a cross-linked structure, and also improves the dispersibility and compatibility of the ceramic powder on the base film, so that the ceramic powder can be evenly coated on the surface of the base film. Compared with the traditional technology of using surfactants to modify ceramic powders, the solution of this application is simple to operate, environmentally friendly and has high production efficiency. At the same time, it also realizes surface modification of ceramic powders at the atomic scale to better improve the dispersibility and compatibility of ceramic powders on the base film; the defects and active sites on the surface of the modified ceramic powder chemically adsorb with the base film to form a cross-linked structure, and the cross-linked structure makes the structure of the diaphragm more stable, thereby improving the problem that the ceramic powder falls off after the diaphragm is soaked in the electrolyte for a long time, that is, improving the structural stability of the diaphragm. At the same time, using plasma modification can also generate hydrophilic groups on the surface of the ceramic powder, such as carbonyl groups, hydroxyl groups, etc., thereby improving the wetting ability of the electrolyte on the diaphragm, reducing the internal resistance of the battery, and enabling the battery to have a good capacity retention rate; because the shape retention ability of the ceramic powder is much greater than that of the base film, the presence of the ceramic powder hinders the thermal shrinkage of the diaphragm, improves the thermal deformation resistance of the diaphragm, and thus improves the performance of the battery.

[0034] In one embodiment, after detecting whether the reaction product of the gas source gas is greater than or equal to a preset reaction product, the following steps are further included: When the reaction product of the gas source gas is less than the preset reaction product, the first gas source and the second gas source are simultaneously introduced for three plasma treatments, wherein the mixing ratio of the first gas source and the second gas source is 1:2 - 3.

[0035] In this embodiment, when the reaction product of the source gas is less than the preset reaction product, it indicates that it is impossible for both the first source gas and the second source gas to be active gases at this time. Then there are the following three situations: 1. The first source gas is an inert gas and the second source gas is also an inert gas; 2. The first source gas is an inert gas and the second source gas is an active gas; 3. The first source gas is an active gas and the second source gas is an inert gas. In all of the above three situations, the first source gas and the second source gas can be introduced simultaneously. This is because when the first source gas and the second source gas are not both active gases at the same time, when the first source gas and the second source gas are introduced simultaneously and under the condition of discharge, the first source gas and the second source gas will not react. And when the first source gas and the second source gas are introduced simultaneously and three plasma treatments are carried out, that is, after the first source gas and the second source gas are introduced and mixed, plasma treatment is carried out, so that the first source gas and the second source gas can simultaneously impact the ceramic powder to modify the ceramic powder. Since the first source gas and the second source gas do not need to be subjected to plasma treatment in two steps, the production efficiency is improved. Further, the active sites and defects on the modified ceramic powder are related to the mixing ratio of the first source gas and the second source gas. This is because the impact paths of the first source gas and the second source gas on the ceramic powder are different, and the generated groups are also inconsistent, so that there are more active sites and defects on the modified ceramic powder. At the same time, when the second source gas uses a gas such as oxygen or a gas containing oxygen element, the oxygen element will form hydrophilic groups with the ceramic powder. When the proportion of the second source gas is larger, more hydrophilic groups are formed on the ceramic powder. Under the condition of ensuring the dispersibility and compatibility of the modified ceramic powder and the base film, the proportion of the dispersant can be reduced to reduce the production cost. In this embodiment, the first source gas introduced is an inert gas, the second source gas introduced is oxygen, and the mixing ratio of the first source gas and the second source gas is 1:3, so that more hydrophilic groups are formed on the ceramic powder.

[0036] It can be understood that for the first source gas and the second source gas that will react under high-power discharge conditions, in order to avoid the reaction of the first source gas and the second source gas after mixing under plasma discharge conditions. For example, when the first source gas is nitrogen and the second source gas is oxygen, nitrogen and oxygen react to form nitric oxide under discharge conditions, resulting in a reduction in the amount of the source gas reacting with the ceramic powder, and further reducing the defects and active sites formed on the surface of the ceramic powder. Therefore, in another embodiment, introducing the source gas into the ceramic powder and performing plasma treatment on the source gas specifically include the following steps: Introduce the first source gas into the ceramic powder and perform primary plasma treatment on the first source gas, where the plasma power supply power is 700W - 800W, the discharge voltage is 900V - 1000V, the discharge current is 2A - 3A, the temperature is 130°C - 150°C, and the reaction time is 20s - 30s; Introduce a second gas source to the ceramic powder and perform secondary plasma treatment on the second gas source. Among them, the power of the plasma power supply is 400W - 500W, the discharge voltage is 700V - 800V, the discharge current is 0.5A - 1A, the temperature is 80°C - 100°C, and the reaction time is 50s - 60s.

[0037] In this embodiment, after introducing the first gas source to the ceramic powder, primary plasma treatment is performed. Under the discharge condition, the first gas source forms a plasma to impact the surface of the ceramic powder and undergo a chemical reaction, so that the ceramic powder and the first gas source form corresponding groups. And the time for introducing the first gas source to the ceramic powder is controlled within 20s - 30s. When the preset time is reached, the input of the first gas source is stopped. At this time, the first gas source completely reacts with the ceramic powder to generate groups under the discharge condition, that is, the first gas source is completely consumed. Specifically, the power parameters of the primary plasma are relatively high, making the impact and reaction between the plasma and the ceramic powder relatively more intense to ensure that the first gas source is consumed during the primary plasma treatment process. Then, after introducing the second gas source to the ceramic powder, secondary plasma treatment is performed. At this time, there is no first gas source in the reaction chamber. Under the discharge condition, the second gas source forms a plasma to impact the ceramic surface and undergo a chemical reaction, so that the ceramic powder and the second gas source form corresponding groups. That is, the power parameters of the secondary plasma treatment are relatively small, making the impact and reaction between the plasma and the ceramic powder more gentle, and further enabling the second gas source to completely react with the ceramic powder within the preset time of 50s - 60s. Specifically, by separately introducing the first gas source and the second gas source, and performing plasma treatment on the first gas source before introducing the second gas source, the first gas source has been completely consumed when the second gas source is introduced. In this way, it is avoided that the first gas source and the second gas source react under the discharge condition of the device, resulting in waste of the first gas source and the second gas source. That is, the objects of action of the first gas source and the second gas source are the ceramic powder, making the defects and active sites formed on the surface of the ceramic powder more diversified and complex, and further improving the dispersibility and compatibility of the ceramic powder on the base film.

[0038] Further, in order to ensure that when the second gas source is introduced, the first gas source has been consumed, so as to ensure that the introduced second gas source can only react with the ceramic powder. In one of the embodiments, after introducing the first gas source to the ceramic powder and performing primary plasma treatment on the first gas source, and before introducing the second gas source to the ceramic powder and performing secondary plasma treatment on the second gas source, the following steps are further included: Obtain the concentration of the first gas source after primary plasma treatment; Match the concentration of the first gas source with the preset concentration; When the concentration of the first gas source is greater than or equal to the preset concentration, increase the power of the plasma power supply, the discharge voltage, the discharge current, and the temperature, and decrease the reaction time.

[0039] It is understandable that after introducing the first gas source and performing the primary plasma treatment, there may still be a situation where the first gas source is not completely consumed. If the second gas source is introduced at this time and the secondary plasma treatment is performed, the introduced second gas source will react with the remaining first gas source under the discharge condition, resulting in a decrease in the amount of the second gas source reacting with the ceramic powder per unit time, and further resulting in a decrease in the active sites and defects generated by the ceramic powder. In this embodiment, after introducing the first gas source and performing the primary plasma treatment, the concentration of the first gas source in the reaction chamber of the equipment is detected to obtain the concentration of the first gas source and match it with the preset concentration. The preset concentration can be designed according to the flow rate of the first gas source introduced per unit time. For example, the preset concentration is designed to be 2% - 3%. When the obtained concentration of the first gas source is greater than the preset concentration, it indicates that there is more remaining first gas source in the reaction chamber at this time, that is, the first gas source has not completely reacted with the ceramic powder. At this time, increase the power of the plasma power supply, amplify the voltage, amplify the current and the temperature, that is, the plasma power supply power is greater than 800W, the discharge voltage is greater than 1000V, the discharge current is greater than 3A, and the temperature is greater than 150°C. After increasing the parameters of the plasma reaction, the reaction between the plasma formed by the remaining first gas source and the ceramic powder becomes more intense, thereby consuming the remaining first gas source, and further making the number of active sites and defects formed by the ceramic powder after the primary plasma treatment more. Further, while increasing the parameters of the plasma reaction, it is also necessary to reduce the plasma startup time, that is, the reaction time should be less than 20s. This is because after increasing the parameters of the plasma reaction, if the reaction time is too long, it will cause the bond energy on the surface of the ceramic powder material itself to break, resulting in a poor performance of the formed diaphragm.

[0040] In another embodiment, matching the concentration of the first gas source with the preset concentration further includes the following steps: When the concentration of the first gas source is less than the preset concentration, start the vacuum device to evacuate the remaining first gas source.

[0041] In this embodiment, when it is detected that the concentration of the first gas source after the primary plasma treatment is less than the preset concentration, that is, the concentration of the first gas source is less than 2%, it indicates that the first gas source has basically reacted completely with the ceramic powder at this time, that is, the remaining first gas source has little effect on the modification effect of the ceramic powder. At this time, start the vacuum device to evacuate the remaining first gas source, so that when the second gas source is introduced into the reaction chamber, there is no remaining first gas source in the reaction chamber, thereby enabling the second gas source to better impact and react with the ceramic powder, making the modification effect of the ceramic powder better.

[0042] Further, in order to ensure that the second gas source introduced reacts completely with the ceramic powder to ensure the performance of the modified ceramic powder, in one embodiment, after introducing the second gas source into the ceramic powder and performing secondary plasma treatment on the second gas source, the following steps are further included: Obtain the concentration of the second gas source; Match the concentration of the second gas source with a preset concentration; When the concentration of the second gas source is greater than or equal to the preset concentration, increase the power, discharge voltage, discharge current and temperature of the plasma power supply, and reduce the reaction time.

[0043] In this embodiment, after introducing the second gas source and performing secondary plasma treatment, the residual concentration of the second gas source is detected. When the concentration of the second gas source is greater than the preset concentration, for example, when the preset concentration is set to 1%-2%, that is, when the concentration of the second gas source is less than or greater than 2%, it indicates that the residual amount of the second gas source is relatively large at this time, that is, the second gas source has not reacted completely with the ceramic powder, and the modification of the ceramic powder has not achieved the expected effect. At this time, by increasing the power, discharge voltage, discharge current and temperature of the plasma power supply, specifically, the plasma power supply power is greater than 500W, the discharge voltage is greater than 800V, the discharge current is greater than 1A, and the temperature is greater than 100°C. After increasing the parameters of the plasma reaction, the reaction between the plasma formed by the residual second gas source and the ceramic powder becomes more intense, thereby consuming the residual second gas source, and further making the number of active sites and defects formed by the ceramic powder after secondary plasma treatment more, and further making the modification effect of the ceramic powder better. Further, while increasing the plasma reaction parameters, reduce the reaction time of the secondary plasma treatment, that is, the reaction time of the secondary plasma treatment should be less than 50s, to avoid the bond energy breakage on the surface of the ceramic powder material itself due to too long reaction time, and further resulting in poor performance of the formed diaphragm.

[0044] In one embodiment, the first gas source is one of nitrogen, helium, argon, oxygen, ammonia, methane and air. It can be understood that the number and type of active sites generated on the surface of the ceramic powder by the plasma formed by different gas sources are different. In this embodiment, nitrogen is used as the first gas source, so that nitrogen forms a plasma during plasma treatment, impacts the surface of the ceramic powder and reacts with the ceramic powder to form groups.

[0045] In one embodiment, the second gas source is one of nitrogen, helium, argon, oxygen, ammonia, methane, and air. It can be understood that there will be trace impurities in the production process of ceramic powder, and these impurities carry trace elements of hydrogen and carbon. When the gas source is an active gas, the gas source will react with these elements under the plasma state to form hydrophilic groups, such as carbonyl or hydroxyl groups. In this embodiment, the second gas source is oxygen. Oxygen forms a plasma during plasma treatment to impact the surface of the ceramic powder and react with the ceramic powder to form groups, making the defects and active sites on the surface of the ceramic powder more diversified. At the same time, oxygen can also react with the ceramic powder to form hydrophilic groups (carbonyl or hydroxyl groups), and the hydrophilic groups can improve the wetting effect of the electrolyte on the separator, thereby reducing the internal resistance of the battery and enabling the battery to have a good capacity retention rate. Further, when the gas source is an inert gas, the inert gas will not react with the ceramic powder under the discharge condition, that is, the inert gas and the ceramic powder will not react to form hydrophilic groups.

[0046] In one embodiment, the dispersant is polyvinylpyrrolidone. In this embodiment, the dispersant is polyvinylpyrrolidone (PVP). Polyvinylpyrrolidone has good dispersibility and can quickly disperse the ceramic powder into the solvent. At the same time, polyvinylpyrrolidone can form a protective layer on the surface of the ceramic powder to prevent the agglomeration and sedimentation of the ceramic powder, thereby making the dispersibility and compatibility between the ceramic powder and the base film better.

[0047] In one embodiment, the solvent is one of N-methylpyrrolidone or water. In this embodiment, the solvent is N-methylpyrrolidone (NMP) or water, so that the modified ceramic powder can be well dissolved in the solvent and then coated on the surface of the base film.

[0048] In one embodiment, the binder is one of polyvinylidene fluoride, sodium carboxymethyl cellulose, and styrene-butadiene rubber. In this embodiment, the binder is one of polyvinylidene fluoride (PVDF), sodium carboxymethyl cellulose (CMC), and styrene-butadiene rubber (SBR), so that the modified ceramic powder coating slurry can be well fixed on the surface of the base film.

[0049] In one embodiment, the base film is one of polypropylene or polyethylene. In this embodiment, the base film is one of polypropylene (PP) or polyethylene (PE), so that the separator has good mechanical strength and high-temperature resistance.

[0050] This application also provides a ceramic separator manufacturing device for implementing the separator preparation process of dispersing ceramic powder and base film to prepare modified ceramic powder. Please refer to Figure 2, The ceramic separator manufacturing device 10 of an embodiment includes a reaction chamber 100, a feeding mechanism 200, a gas source mechanism 300, a plasma reaction mechanism 400, and a controller (not shown in the figure). The feeding mechanism 200 includes a feeding bin 210 and a discharging bin 220. The feeding bin 210 and the discharging bin 220 are respectively communicated with the reaction chamber 100. The feeding bin 210 is used to convey the ceramic powder into the reaction chamber 100, and the discharging bin 200 is used to collect and output the ceramic powder in the reaction chamber 100. The gas source mechanism 300 is communicated with the reaction chamber 100, and the gas source mechanism 300 is used to convey the gas source into the reaction chamber 100. The plasma reaction mechanism 400 is communicated with the reaction chamber 100, and the acting end of the plasma reaction mechanism 400 is located in the reaction chamber 100. The plasma reaction mechanism 400 is used to plasmaize the gas source. The controller is electrically connected to the gas source mechanism 300 and the plasma reaction mechanism 400 respectively, so that the gas source mechanism 300 fluidizes the ceramic powder in the reaction chamber 100, and the plasma reaction mechanism 400 plasmaizes the gas source in the reaction chamber 100. Specifically, the controller controls the flow rate of the gas source mechanism, as well as the power, discharge voltage, discharge current, and temperature of the plasma reaction mechanism.

[0051] The present application also provides a ceramic separator, which is prepared by using the ceramic separator manufacturing device described in any of the above embodiments.

[0052] Compared with the prior art, the present disclosure has at least the following advantages: 1. In the above-mentioned diaphragm preparation process of dispersing ceramic powder and base film, a gas source is introduced into the ceramic powder for fluidization treatment. The flow rate of the gas source is 80 sccm - 100 sccm, so that the ceramic powder is in a suspended state to reduce the agglomeration between ceramic powders, and at the same time, the gas source and the ceramic powder are fully mixed. Then, the gas source is subjected to plasma treatment, wherein the plasma power is 400 W - 800 W, the discharge voltage is 700 V - 1000 V, the discharge current is 0.5 A - 3 A, and the temperature is 80 °C - 150 °C, so that the gas source forms a plasma, and the plasma impacts the surface of the ceramic powder, causing many defects and active sites on the surface of the ceramic powder, thereby modifying the ceramic powder. The existence of these defects and active sites enables the ceramic powder to chemically adsorb with the base film to form a cross-linked structure, and also improves the dispersibility and compatibility of the ceramic powder on the base film, so that the ceramic powder can be evenly coated on the surface of the base film. Compared with the traditional technology of using surfactants to modify ceramic powder, the solution of the present application is simple to operate, environmentally friendly, and has high production efficiency. At the same time, it also realizes surface modification of the ceramic powder at the atomic scale to better improve the dispersibility and compatibility of the ceramic powder on the base film.

[0053] 2. The defects and active sites on the surface of the modified ceramic powder undergo chemical adsorption with the base membrane to form a cross-linked structure. The cross-linked structure makes the structure of the diaphragm more stable, thereby improving the problem of ceramic powder falling off after long-term immersion in electrolyte, that is, improving the structural stability of the diaphragm; at the same time, plasma modification can also produce hydrophilic groups on the surface of the ceramic powder, such as carbonyl, hydroxyl, etc., thereby improving the wetting ability of the electrolyte on the diaphragm, reducing the internal resistance of the battery, and making the battery have a better capacity retention rate.

[0054] 3. Since the shape retention ability of ceramic powder is much greater than that of base film, the presence of ceramic powder hinders the thermal shrinkage of the diaphragm, improves the diaphragm's resistance to thermal deformation, and thus improves the performance of the battery.

[0055] Some specific examples are listed below, and if % is mentioned, it means percentage by weight. It should be noted that the following examples do not exhaust all possible situations, and the materials used in the following examples can be obtained from commercial sources unless otherwise specified.

[0056] Example 1 Add ceramic powder to the plasma feed bin, open the feed valve to allow the ceramic powder to enter the reactor, then introduce air, adjust the air flow rate to make the ceramic powder in a fluidized state, open the air outlet valve and the vacuum pump at the same time, finally turn on the plasma power supply, adjust the plasma power, discharge voltage, discharge current, and temperature, the processing time is 90s, then close the air outlet valve, open the discharge valve to discharge and collect the modified ceramic powder; The glue solution was prepared with the binder PVDF accounting for 6% by mass. The modified ceramic powder was added into the melting barrel and stirred at low speed for 2 h. The melting barrel was opened and vacuum (5. 2×10 －3 Pa) high-speed stirring for 20 h, and finally adding 1% of dispersant PVP to fully disperse the materials to form a uniform ceramic powder slurry; The slurry was evenly coated on both sides of the dry PP base film using a micro-gravure coater, and the coated base film was placed at 80 ° C in a vacuum (5. 2 × 10 －3 Pa) and dried for 24 h to obtain the modified ceramic / PP composite membrane.

[0057] Example 2 Add ceramic powder to the plasma feed bin, open the feed valve to allow the ceramic powder to enter the reactor, then introduce air, adjust the air flow rate to make the ceramic powder in a fluidized state, open the air outlet valve and the vacuum pump at the same time, finally turn on the plasma power supply, adjust the plasma power, discharge voltage, discharge current, and temperature, the processing time is 90s, then close the air outlet valve, open the discharge valve to discharge and collect the modified ceramic powder; Prepare a glue solution with the mass fraction of binder PVDF being 6%. Add the modified ceramic powder into the melting barrel and stir at a low speed for 2 h. Open the melting barrel and stir at a high speed under vacuum (5.2×10 －3 Pa) for 20 h. Finally, add 0.8% of dispersant PVP to fully disperse the materials and form a uniform ceramic powder slurry; Use a microgravure coater to uniformly coat the above slurry on both sides of the dry-process PP base film. Place the coated base film in a vacuum (5.2×10 －3 Pa) at 80 °C and dry for 24 h to obtain the modified ceramic / PP composite separator.

[0058] Example 3 Add the ceramic powder into the plasma feed bin. Open the feed valve to allow the ceramic powder to enter the reactor. Then introduce helium gas, adjust the air flow rate to make the ceramic powder in a fluidized state. At the same time, open the outlet valve and the vacuum pump. Finally, turn on the plasma power supply and adjust the plasma power, discharge voltage, discharge current, and temperature. The treatment time is 90 s. Then close the outlet valve, open the discharge valve to discharge and collect the modified ceramic powder; Prepare a glue solution with the mass fraction of binder PVDF being 6%. Add the modified ceramic powder into the melting barrel and stir at a low speed for 2 h. Open the melting barrel and stir at a high speed under vacuum (5.2×10 －3 Pa) for 20 h. Finally, add 1% of dispersant PVP to fully disperse the materials and form a uniform ceramic powder slurry; Use a microgravure coater to uniformly coat the above slurry on both sides of the dry-process PP base film. Place the coated base film in a vacuum (5.2×10 －3 Pa) at 80 °C and dry for 24 h to obtain the modified ceramic / PP composite separator.

[0059] Example 4 Add the ceramic powder into the plasma feed bin. Open the feed valve to allow the ceramic powder to enter the reactor. Then introduce oxygen, adjust the air flow rate to make the ceramic powder in a fluidized state. At the same time, open the outlet valve and the vacuum pump. Finally, turn on the plasma power supply and adjust the plasma power, discharge voltage, discharge current, and temperature. The treatment time is 90 s. Then close the outlet valve, open the discharge valve to discharge and collect the modified ceramic powder; Prepare a glue solution with the mass fraction of binder PVDF being 6%. Add the modified ceramic powder into the melting barrel and stir at a low speed for 2 h. Open the melting barrel and stir at a high speed under vacuum (5.2×10 －3 Pa) for 20 h. Finally, add 1% of dispersant PVP to fully disperse the materials and form a uniform ceramic powder slurry; The above slurry was evenly coated on both sides of the dry-process PP base film using a gravure coater, and the coated base film was placed in a vacuum (5.2×10 －3 Pa) at 80 °C and dried for 24 h to obtain the modified ceramic / PP composite separator.

[0060] Example 5 The ceramic powder was added to the plasma feed bin, the feed valve was opened to allow the ceramic powder to enter the reactor, and then helium was introduced. The air flow rate was adjusted to make the ceramic powder in a fluidized state. At the same time, the outlet valve and the vacuum pump were opened. Finally, the plasma power supply was turned on for 30 s, and the plasma power, discharge voltage, discharge current, and temperature were adjusted. Then, the introduction of helium was stopped and oxygen was introduced. After 60 s, the outlet valve was closed, the discharge valve was opened to discharge the material, and the modified ceramic powder was collected; A glue solution was prepared with the binder PVDF accounting for 6% by mass fraction. The modified ceramic powder was added to the melting slurry barrel and stirred at a low speed for 2 h; the melting slurry barrel was opened, and it was stirred at a high speed under vacuum (5.2×10 －3 Pa) for 20 h. Finally, 1% of the dispersant PVP was added to fully disperse the material to form a uniform ceramic powder slurry; The above slurry was evenly coated on both sides of the dry-process PP base film using a gravure coater, and the coated base film was placed in a vacuum (5.2×10 －3 Pa) at 80 °C and dried for 24 h to obtain the modified ceramic / PP composite separator.

[0061] Example 6 The ceramic powder was added to the plasma feed bin, the feed valve was opened to allow the ceramic powder to enter the reactor, and then helium was introduced. The air flow rate was adjusted to make the ceramic powder in a fluidized state. At the same time, the outlet valve and the vacuum pump were opened. Finally, the plasma power supply was turned on for 30 s, and the plasma power, discharge voltage, discharge current, and temperature were adjusted. Then, the introduction of helium was stopped and oxygen was introduced. After 60 s, the outlet valve was closed, the discharge valve was opened to discharge the material, and the modified ceramic powder was collected; A glue solution was prepared with the binder PVDF accounting for 6% by mass fraction. The modified ceramic powder was added to the melting slurry barrel and stirred at a low speed for 2 h; the melting slurry barrel was opened, and it was stirred at a high speed under vacuum (5.2×10 －3 Pa) for 20 h. Finally, 0.8% of the dispersant PVP was added to fully disperse the material to form a uniform ceramic powder slurry; The above slurry was evenly coated on both sides of the dry-process PP base film using a gravure coater, and the coated base film was placed in a vacuum (5.2×10 －3 Pa) at 80 °C and dried for 24 h to obtain the modified ceramic / PP composite separator.

[0062] Comparative Example 1 Purchased dry-process PP separator.

[0063] Comparative Example 2 Prepare a glue solution with PVDF at a mass fraction of 6%, add the unmodified ceramic powder into the melting slurry tank, and stir at a low speed for 2 h; open the melting slurry tank, and stir at a high speed under vacuum (5.2×10 －3 Pa) for 20 h. Finally, add 1% dispersant PVP to fully disperse the materials to form a uniform ceramic powder slurry; Use a microgravure coater to evenly coat the two sides of the dry-process PP base film with the above slurry, and place the coated base film in a vacuum (5.2×10 －3 Pa) at 80 °C for drying for 24 h to obtain an unmodified ceramic / PP composite separator.

[0064] The modified ceramic / PP composite separators of Examples 1 to 6 and the unmodified ceramic / PP composite separators of Comparative Examples 1 to 2 were used to prepare button cells. The positive electrode active material of the button cell was lithium iron phosphate, and the negative electrode active material was graphite. The separators of the above button cells were tested for tensile strength, puncture strength, thermal shrinkage and cycling performance. The obtained data are shown in the following figure: As can be seen from the above table, the performance of the ceramic / PP composite separator is better than that of the ordinary dry-process PP separator in Comparative Example 1. The performance of the separator prepared with the ceramic powder modified by a plasma powder modifier is also better than that of the unmodified ceramic / PP separator in Comparative Example 2. Among them, the thermal shrinkage is greatly reduced because many defects and active sites are generated on the surface of the modified ceramic powder. The existence of these defects and active sites enables chemical adsorption between the ceramic particles and the PP base film to form a cross-linked structure, while improving the dispersibility and compatibility of the ceramic slurry on the PP base film, so that the ceramic can be evenly coated on the surface of the PP separator. At the same time, the cross-linked structure also makes the structure of the separator more stable, thereby improving the problem that the ceramic falls off after the separator is soaked in the electrolyte for a long time. Further, since the shape retention ability of the ceramic is much greater than that of the base film, the presence of the ceramic hinders the thermal shrinkage of the separator and improves the thermal deformation resistance of the separator. Plasma modification can also make hydrophilic groups such as carbonyl and hydroxyl groups generated on the surface of the ceramic powder, thereby improving the wetting ability of the electrolyte to the separator, reducing the internal resistance of the battery, and enabling the battery to have a good capacity retention rate.

[0065] The difference between Example 1 and Example 3 lies in the use of different plasma gas sources. Different plasma gas sources can cause differences in the quantity and types of active sites generated on the particle surface. The compressed air used in Experimental Case 1 contains various gas molecules such as nitrogen and oxygen, which makes the active sites generated on the surface of alumina ceramics more diversified. Moreover, the oxygen molecules among them can cause the organic substances on the particle surface to undergo oxidation reactions to generate more hydrophilic groups, thereby making the separator prepared in Example 1 superior to the separator prepared in Example 3 (with the gas source being He).

[0066] Compared with Example 1, in Example 2, and compared with Example 6, in Example 5, when preparing the ceramic slurry, the amount of dispersant added is less, but the performance of the separator prepared with its slurry changes little. This shows that the plasma-modified alumina ceramic particles have good dispersibility, and the amount of dispersant can be appropriately reduced when preparing the slurry, so as to achieve the effect of cost reduction and efficiency improvement.

[0067] When Example 5 is compared with Examples 3 and 4, the performance of its separator is improved to a certain extent. This is because when using He alone as the plasma gas source, it mainly plays a role of physical bombardment, which can remove some impurities on the particle surface and cause surface defects of the particles. However, this effect has certain limitations. When He is first introduced for physical bombardment for 30 s and then O2 is introduced as the plasma gas source, O2 can better contact the particle surface to generate more defects and hydrophilic groups.

[0068] In summary, by performing plasma treatment on the surface of ceramic powder, more active sites, defects, and hydrophilic groups are formed on the surface of the ceramic powder. Furthermore, chemical adsorption occurs between the ceramic powder and the base film to form a cross-linked structure, improving the dispersibility and compatibility of the ceramic slurry on the base film, enabling the ceramic slurry to be coated on the surface of the base film more uniformly, and thus comprehensively optimizing the performance (mechanical properties, thermal properties, and electrochemical properties) of the alumina ceramic separator.

[0069] The above-described embodiments merely represent several implementation manners of the present disclosure. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present disclosure, several modifications and improvements can still be made, and these all belong to the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure patent shall be subject to the appended claims.

Claims

1. A process for preparing a diaphragm in which ceramic powder and base film are dispersed, characterized in that: The following steps are involved: Obtaining ceramic powder; A gas source is introduced into the ceramic powder to fluidize the ceramic powder so that the gas source is mixed with the ceramic powder, and the flow rate of the gas source is 80 sccm-100 sccm; Plasma treatment is performed on the gas source to form plasma, and the plasma is made to impact the surface of the ceramic powder to obtain modified ceramic powder, wherein the plasma power is 400W-800W, the discharge voltage is 700V-1000V, the discharge current is 0.5A-3A, and the temperature is 80°C-150°C; Mixing a binder, a dispersant and the modified ceramic powder in a solvent to obtain a modified ceramic powder coating slurry, wherein the ratio of the binder, the modified ceramic powder and the dispersant is 5:93-94:1-2; The modified ceramic powder coating slurry is coated on the base membrane to obtain a modified ceramic powder composite diaphragm; wherein, The ceramic powder is introduced with a gas source to perform fluidization treatment on the ceramic powder so as to mix the gas source with the ceramic powder, which specifically includes the following steps: Passing a first gas source into the ceramic powder to impact the surface of the ceramic powder; Passing a second gas source into the ceramic powder to impact the surface of the ceramic powder; as well as, obtaining the gas type of the second gas source; Performing gas type product processing on the gas type and the preset type to obtain a gas source gas reaction product; Detecting whether the source gas reaction product is greater than or equal to a preset reaction product; When the gas source gas reaction product is greater than or equal to the preset reaction product, the first gas source and the second gas source are introduced in different time periods to perform primary plasma treatment and secondary plasma treatment.

2. The process for preparing a diaphragm in which ceramic powder and base film are dispersed according to claim 1, characterized in that: After detecting whether the source gas reaction product is greater than or equal to the preset reaction product, the following steps are also included: When the gas source gas reaction product is less than a preset reaction product, the first gas source and the second gas source are introduced simultaneously to perform three plasma treatments, wherein the mixing ratio of the first gas source and the second gas source is 1:2-3.

3. The process for preparing a diaphragm in which ceramic powder and base film are dispersed according to claim 1, characterized in that: The first gas source is one of nitrogen, helium, argon, oxygen, ammonia, methane and air.

4. The process for preparing a diaphragm in which ceramic powder and base film are dispersed according to claim 1, characterized in that: The second gas source is one of nitrogen, helium, argon, oxygen, ammonia, methane and air.

5. The process for preparing a diaphragm with dispersed ceramic powder and base film according to claim 1, characterized in that: The dispersant is polyvinyl pyrrolidone.

6. The process for preparing a diaphragm with dispersed ceramic powder and base film according to claim 1, characterized in that: The solvent is one of N-methylpyrrolidone or water.

7. The process for preparing a diaphragm with dispersed ceramic powder and base film according to claim 1, characterized in that: The binder is one of polyvinylidene fluoride, sodium carboxymethyl cellulose and styrene-butadiene rubber.

8. The process for preparing a diaphragm with dispersed ceramic powder and base film according to claim 1, characterized in that: The base film is one of polypropylene or polyethylene.

9. A ceramic diaphragm manufacturing device, characterized in that: include: Reaction chamber; A feeding mechanism, the feeding mechanism comprising a feeding bin and a discharging bin, the feeding bin and the discharging bin are respectively connected to the reaction bin, the feeding bin is used to transport the ceramic powder into the reaction bin, and the discharging bin is used to collect and output the ceramic powder in the reaction bin; An air source mechanism, the air source mechanism is connected to the reaction chamber, and the air source mechanism is used to transport the air source into the reaction chamber; A plasma reaction mechanism, the plasma reaction mechanism is communicated with the reaction chamber, an action end of the plasma reaction mechanism is located in the reaction chamber, and the plasma reaction mechanism is used to plasmatize the gas source; A controller is electrically connected to the gas source mechanism and the plasma reaction mechanism, respectively, so that the gas source mechanism performs fluidization treatment on the ceramic powder in the reaction chamber, and the plasma reaction mechanism performs plasma treatment on the gas source in the reaction chamber.

10. A ceramic diaphragm, characterized in that: The ceramic diaphragm is prepared using the ceramic diaphragm manufacturing equipment described in claim 9.

Images