Composite cathode material, preparation method thereof and battery

Abstract

The present application relates to the technical field of energy storage devices, in particular to a composite cathode material, a preparation method thereof and a battery. The composite cathode material comprises a polyaryletherketone matrix material with a porous structure and a cathode component, and the cathode component is loaded on the polyaryletherketone matrix material. The composite cathode material effectively controls the expansion and contraction of the cathode material during the charging and discharging process of the solid-state battery, thereby maintaining stable battery capacity. The composite cathode has excellent mechanical properties and flexibility, which can prevent lithium dendrite puncture from causing short circuit with the cathode, ensuring the safety of the solid-state battery during cycling.

Description

Technical Field

[0001] This invention relates to the field of energy storage device technology, and more specifically, to composite cathode materials, their preparation methods, and batteries. Background Technology

[0002] As the most widely used energy storage device, batteries have dominated the portable electronic device market since their inception in the 1990s due to their superior energy and power density. Developing high-performance batteries is of great strategic significance for environmental protection, energy efficiency, and many other aspects. Currently, liquid electrolytes are commonly used in battery systems, which are prone to leakage, short circuits, and potentially dangerous accidents such as battery combustion and explosion. The use of solid-state electrolytes can reduce the proportion of flammable materials in the battery and, to some extent, suppress dendrite growth on the negative electrode, thus preventing short circuits. Therefore, solid-state batteries offer higher safety compared to liquid batteries. However, during the operation of solid-state batteries, issues arise such as the volume expansion and contraction of the positive electrode material and the high impedance and stability of the solid / solid interfaces between the various components (including active materials, solid electrolytes, and conductive additives). These issues hinder the transport of alkali metal ions, increase the internal resistance of the battery, and ultimately lead to rapid capacity decay.

[0003] In view of this, the present invention is proposed. Summary of the Invention

[0004] The purpose of this invention is to provide a composite cathode material, its preparation method, and a battery. The composite cathode material provided in this invention effectively controls the expansion and contraction of the cathode material during the charging and discharging process of a solid-state battery, thereby maintaining a stable battery capacity. This composite cathode possesses excellent mechanical properties and flexibility, preventing lithium dendrite puncture that could lead to short circuits with the cathode, thus ensuring the safety of the solid-state battery during cycling.

[0005] This invention is implemented as follows:

[0006] In a first aspect, the present invention provides a composite cathode material comprising a polyaryletherketone matrix material having a porous structure and a cathode component, wherein the cathode component is loaded on the polyaryletherketone matrix material.

[0007] In an optional embodiment, the positive electrode component is attached to the porous structure of the polyaryletherketone matrix material.

[0008] In an optional embodiment, the polyaryletherketone matrix material is selected from any one of polyetheretherketone matrix materials, polyetherketone matrix materials, polyetherketone ketone matrix materials, polyetheretherketone ketone matrix materials, and polyetherketone etherketone ketone matrix materials.

[0009] In an optional embodiment, the positive electrode component includes any one or a combination of two or more of the following: positive electrode active material, electrolyte, conductive agent, and binder;

[0010] Preferably, the positive electrode active material includes a material containing one or more of nickel, cobalt, and manganese;

[0011] Preferably, the positive electrode active material includes one or more of lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium manganese oxide, lithium nickel manganese oxide, lithium cobalt manganese oxide, lithium-rich manganese-based materials, and nickel manganese spinel.

[0012] Preferably, the conductive agent is selected from carbon-containing materials, and more preferably from carbon black materials and graphite materials; more preferably, it is at least one of conductive graphite, conductive carbon black, acetylene black, carbon nanotubes and carbon nanofibers, and more preferably, it is conductive graphite;

[0013] Preferably, the adhesive is selected from polymers, and more preferably from any one of ester polymers, amine polymers and olefin polymers; more preferably from at least one of polyvinylidene fluoride, polyimide and polyacrylate, and most preferably from polyvinylidene fluoride;

[0014] Preferably, the positive electrode active material is selected from inorganic particles, preferably an alkaline phosphate salt, and more preferably an alkaline aluminum titanium phosphate salt.

[0015] Secondly, the present invention provides a method for preparing the composite cathode material described in the foregoing embodiments, comprising: loading the cathode component onto the polyaryletherketone matrix material.

[0016] In an optional implementation, the method includes: preparing a dispersion of a positive electrode component containing a positive electrode component;

[0017] Preferably, the step of forming the positive electrode component dispersion includes: mixing the first solvent, positive electrode active material, electrolyte, conductive agent, and binder evenly;

[0018] Preferably, the step of forming the positive electrode component dispersion includes: mixing the first solvent and the positive electrode active material evenly, and then mixing them evenly with the conductive agent and the binder in sequence;

[0019] Preferably, the conditions during the mixing process include: a rotation speed of 200–500 rpm and a time of 2–3 hours.

[0020] In an optional embodiment, the first solvent is selected from alcohol solvents, preferably monohydric alcohols, more preferably C1-C10 monohydric alcohols, even more preferably C1-C5 monohydric alcohols, and more preferably any one or a combination of two or more of methanol, ethanol, propanol, propylene glycol, glycerol, ethylene glycol and isopropanol.

[0021] Preferably, the positive electrode component includes any one or a combination of two or more of the following: positive electrode active material, electrolyte, conductive agent, and binder;

[0022] Preferably, the positive electrode active material includes a material containing one or more of nickel, cobalt, and manganese;

[0023] Preferably, the positive electrode active material includes one or more of lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium manganese oxide, lithium nickel manganese oxide, lithium cobalt manganese oxide, lithium-rich manganese-based materials, and nickel manganese spinel.

[0024] Preferably, the conductive agent is selected from carbon-containing materials, and more preferably from carbon black materials and graphite materials; more preferably, it is at least one of conductive graphite, conductive carbon black, acetylene black, carbon nanotubes and carbon nanofibers, and more preferably, it is conductive graphite;

[0025] Preferably, the adhesive is selected from polymers, and more preferably from any one of ester polymers, amine polymers and olefin polymers; more preferably from at least one of polyvinylidene fluoride, polyimide and polyacrylate, and most preferably from polyvinylidene fluoride;

[0026] Preferably, the positive electrode active material is selected from inorganic particles, preferably an alkaline phosphate salt, and more preferably an alkaline aluminum titanium phosphate salt.

[0027] In an optional embodiment, the mass of the positive electrode active material accounts for 65-85% of the total mass of the positive electrode component dispersion, preferably 70-80%.

[0028] Preferably, the electrolyte accounts for 10-25% of the total mass of the positive electrode component dispersion, and more preferably 15-20%.

[0029] Preferably, the conductive agent accounts for 3-10% of the total mass of the positive electrode component dispersion, more preferably 3-9%.

[0030] Preferably, the mass of the binder accounts for 1-10% of the total mass of the positive electrode component dispersion, more preferably 1-5%;

[0031] Preferably, the concentration of the first solvent is 80% to 99.9%, more preferably 95% to 99.5%.

[0032] In an optional embodiment, the method includes: preparing a polyaryletherketone matrix solution containing polyaryletherketone;

[0033] Preferably, the preparation step of the polyaryletherketone matrix solution includes: mixing and dissolving the second solvent and the polyaryletherketone powder;

[0034] Preferably, the conditions for the dissolution process include: a temperature of 250-280℃, more preferably 260-270℃; a rotation speed of 200-500 rpm; and a time of 1-3 hours.

[0035] Preferably, the solid content of the polyaryletherketone matrix solution is 5-20%, more preferably 5-15%;

[0036] Preferably, the melt index of the polyaryletherketone powder is 8-15;

[0037] Preferably, the second solvent is selected from sulfoxide solvents or alkane-ketone solvents, more preferably from tetramethyl sulfoxide, diphenyl sulfone, dimethyl sulfoxide and N-methylpyrrolidone, and more preferably tetramethyl sulfoxide;

[0038] The polyaryletherketone powder is selected from any one of polyetheretherketone powder, polyetherketone powder, polyetherketone ketone powder, polyetheretherketone ketone powder, and polyetherketone etherketone ketone powder.

[0039] In optional embodiments, the method includes: using thermally induced phase separation, liquid blending technology and site-occupancy method to load the positive electrode component onto the polyaryletherketone matrix material;

[0040] Preferably, the method includes: mixing a dispersion of a positive electrode component containing a positive electrode component and a polyaryletherketone matrix solution containing a polyaryletherketone under heating conditions to form a mixture;

[0041] Preheat the current collector, and then coat the current collector with the mixture;

[0042] Next, cooling, washing, and drying are carried out.

[0043] In an optional embodiment, the heating temperature is 250-280°C, preferably 260-270°C;

[0044] Preferably, the preheating temperature is 220-260℃, and more preferably 240-250℃;

[0045] Preferably, the thickness of the coated film is 0.2-1 mm, more preferably 0.3-0.6 mm;

[0046] Preferably, the drying conditions include a drying temperature of 80-100℃ and a drying time of 20-30h.

[0047] Thirdly, the present invention provides a battery comprising the composite cathode material described in the foregoing embodiments;

[0048] Preferably, the battery is a solid-state battery.

[0049] The present invention has the following beneficial effects: The composite cathode material provided in the embodiments of the present invention uses a polyaryletherketone matrix material, whose porous structure effectively controls the expansion and contraction of the cathode material during the charging and discharging process of the solid-state battery, thereby maintaining a stable battery capacity and giving the material good cycle stability. At the same time, it has excellent mechanical strength and good flexibility, which can prevent short circuits between the cathode and metal anode due to dendrite puncture, thereby reducing the risk of short circuits during cycling and improving battery safety. Attached Figure Description

[0050] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0051] Figure 1 This is a schematic diagram of the structure of the composite cathode material provided in an embodiment of the present invention;

[0052] Figure 2 This is a scanning electron microscope image of the composite cathode material provided in Embodiment 2 of the present invention;

[0053] Figure 3 This is a scanning electron microscope image of the polyetheretherketone matrix material provided in Comparative Example 5 of the present invention. Detailed Implementation

[0054] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0055] In a first aspect, the present invention provides a composite cathode material comprising a polyaryletherketone matrix material having a porous structure and a cathode component, wherein the cathode component is loaded on the polyaryletherketone matrix material.

[0056] During the charge and discharge process of solid-state batteries, the positive electrode material undergoes volume expansion, leading to component shedding during repeated volume changes. These detached components, lacking electrical contact, are unable to participate in subsequent electrochemical reactions, resulting in permanent capacity decay. The composite positive electrode material provided in this invention utilizes a polyaryletherketone (PAK) matrix material with a porous structure. This provides sufficient space for the positive electrode active material to mitigate volume expansion, resulting in good cycle stability. Furthermore, the PAK matrix material improves the interfacial stability between the positive electrode and electrolyte, inhibiting chemical reactions between the positive electrode active material and the electrolyte, significantly enhancing the electrochemical performance of the solid-state battery. Additionally, during charge and discharge cycles, when alkali metal ions deposit on the negative electrode material of the solid-state battery, lithium dendrites are generated due to the tip discharge effect. These dendrites, after piercing the electrolyte layer, short-circuit with the positive electrode, causing a short circuit. Because PAK material possesses high mechanical properties and good flexibility, it can prevent dendrite penetration, protecting the positive electrode material and thus improving the safety of the solid-state battery.

[0057] Specifically, the porous structure of the polyaryletherketone matrix material provides attachment sites for positive electrode components such as positive electrode active materials, electrolytes, and conductive agents (see [reference]). Figure 1 This allows the cathode components to be evenly dispersed, and the porous structure effectively controls the expansion and contraction of the cathode material during the charging and discharging process of the solid-state battery, thereby maintaining a stable battery capacity.

[0058] Polyaryletherketone (PAEK) is a class of crystalline polymers composed of phenylene rings linked by ether bonds and carbonyl (ketone) groups. Depending on the order and ratio of ether bonds, ketone groups, and benzene rings in the molecular chain, many different polymers can be formed. The main varieties include polyetheretherketone (PEEK), polyetherketone (PEK), polyetherketoneketone (PEKK), polyetheretherketoneketone (PEEKK), and polyetherketoneetherketoneketone (PEKEKK). The rigid benzene rings in the PAEK molecular structure give it excellent high-temperature performance, mechanical properties, electrical insulation, radiation resistance, and chemical resistance. The ether bonds in the PAEK molecular structure also provide it with good flexibility, allowing it to be molded using methods for thermoplastic engineering plastics.

[0059] In this embodiment of the invention, the polyaryletherketone matrix material is selected from any one of polyetheretherketone matrix materials, polyetherketone matrix materials, polyetherketone ketone matrix materials, polyetheretherketone ketone matrix materials, and polyetherketone etherketone ketone matrix materials.

[0060] The embodiments of the present invention are illustrated using polyetheretherketone as an example, but other polyaryletherketones can also be used.

[0061] Furthermore, the positive electrode component includes any one or more combinations of positive electrode active material, electrolyte, conductive agent and binder.

[0062] The positive electrode active material includes materials containing any one or more combinations of nickel, cobalt and manganese; for example, the positive electrode active material includes, but is not limited to, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium manganese oxide, lithium nickel manganese oxide, lithium cobalt manganese oxide, lithium-rich manganese-based materials and nickel manganese spinel, or one or more of these.

[0063] The binder is selected from polymers, preferably any one of ester polymers, amine polymers and olefin polymers; for example, including but not limited to at least one of polyvinylidene fluoride, polyimide and polyacrylate, with polyvinylidene fluoride being the most preferred.

[0064] The positive electrode active material is selected from inorganic particles, preferably an alkaline phosphate salt, and more preferably an alkaline aluminum titanium phosphate salt.

[0065] The conductive agent is selected from carbon-containing materials, preferably carbon black materials and graphite materials; for example, including but not limited to at least one of conductive graphite, conductive carbon black, acetylene black, carbon nanotubes and carbon nanofibers, more preferably conductive graphite.

[0066] Since heating is required during the preparation of the composite cathode material in this embodiment of the invention, the cathode active material and conductive agent used are materials that need to be resistant to high temperatures. If materials that are not resistant to high temperatures are selected, they will decompose during the subsequent heating process, which will result in the inability to prepare the required composite cathode material.

[0067] It should be noted that: (1) The alkali metal ions in the inorganic particles are determined according to the battery to be prepared. For example, if a lithium battery is to be prepared, the inorganic particles are lithium inorganic particles; if a sodium battery is to be prepared, the inorganic particles are sodium inorganic particles.

[0068] (2) The selection of the above positive electrode components refers to the raw materials that can be purchased. The positive electrode active material, electrolyte, conductive agent and binder are not limited to the selection of the embodiments of the present invention. The embodiments of the present invention select materials with better effects. Other materials that can be purchased and meet the requirements of the embodiments of the present invention are also within the protection scope of the embodiments of the present invention.

[0069] Secondly, the present invention provides a method for preparing the composite cathode material described in the foregoing embodiments, comprising:

[0070] S1, positive electrode component dispersion;

[0071] The first solvent, positive electrode active material, electrolyte, conductive agent, and binder are mixed evenly to form a positive electrode component dispersion. Specifically, the positive electrode active material is added to the first solvent and stirred evenly to form a homogeneous solution. Then, the conductive agent and binder are added to the solution in sequence and stirred thoroughly to ensure that the materials are evenly dispersed in the first solvent, thereby forming the positive electrode component dispersion.

[0072] Throughout the mixing process, the stirring speed is 200-500 rpm, and the time is 2-3 hours. For example, the stirring speed can be any value between 200-500 rpm or any range between two values, such as 200 rpm, 300 rpm, 400 rpm, and 500 rpm, and the time can be any value between 2 hours, 2.5 hours, and 3 hours, or any range between two values.

[0073] The first solvent is selected from alcohol solvents, preferably monohydric alcohols, more preferably C1-C10 monohydric alcohols, and even more preferably C1-C5 monohydric alcohols, such as any one or more combinations of methanol, ethanol, propanol, propylene glycol, glycerol, ethylene glycol and isopropanol.

[0074] The mass concentration of the first solvent is 80% to 99.9%, for example, any value between 80% and 99.9%, or a range between any two values, such as 80%, 85%, 90%, 95%, 99.5%, and 99.9%. Preferably, it is 95% to 99.5%.

[0075] For the limitations of other components in the positive electrode composition, such as the positive electrode active material, electrolyte, conductive agent and binder, please refer to the above description.

[0076] Furthermore, the mass of the highly active material accounts for 65-85% of the total mass of the positive electrode component dispersion, for example, any value between 65-85% or any range between any two values, such as 65%, 70%, 75%, 80%, and 85%. Preferably, it is 70-80%.

[0077] The mass of the electrolyte accounts for 10-25% of the total mass of the positive electrode component dispersion, for example, any value between 10-25% or any range between any two values, such as 10%, 15%, 20% and 25%, preferably 15-20%.

[0078] The conductive agent accounts for 3-10% of the total mass of the positive electrode component dispersion, for example, any value between 3% and 10%, or any range between any two values, such as 3%, 4%, 5%, 6%, 7%, 8%, 9%, and 10%, preferably 3-9%.

[0079] The mass of the binder accounts for 1-10% of the total mass of the positive electrode component dispersion, for example, any value between 1% and 10% or any range between any two values, such as 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, and 10%, preferably 1-5%.

[0080] S2, forming a polyaryletherketone matrix solution;

[0081] The second solvent and polyaryletherketone (PAK) powder are mixed and dissolved to form a PAK matrix solution. Specifically, the second solvent is poured into a homogenizer, and then a certain amount of PAK powder is added to the homogenizer. The mixture is heated and stirred at high speed to fully dissolve the PAK powder in the second solvent. After maintaining the solution at this temperature and stirring for a period of time, the PAK matrix solution is obtained.

[0082] The conditions for the solution process include: a temperature of 250-280℃, such as any value or range between 250℃, 260℃, 270℃, and 280℃, preferably 260-270℃; a rotational speed of 200-500 rpm, such as any value or range between 200 rpm, 300 rpm, 400 rpm, and 500 rpm; and a time of 1-3 hours, such as any value or range between 1h, 2h, 2.5h, and 3h.

[0083] The solid content of the polyaryletherketone matrix solution is 5-20%, for example, any value between 5% and 20% or any range between any two values, such as 5%, 10%, 15% and 20%, preferably 5-15%.

[0084] The solid content of the polyaryletherketone matrix solution mentioned above refers to the ratio of the mass of the polyaryletherketone powder to the mass of the polyaryletherketone matrix solution.

[0085] The melt index of polyaryletherketone powder is 8-15; for example, any value between 8 and 15 or any range between any two values, such as 8, 9, 10, 11, 12, 13, 14 and 15.

[0086] The polyaryletherketone powder is selected from any one of polyetheretherketone powder, polyetherketone powder, polyetherketoneketone powder, polyetheretherketoneketone powder, and polyetherketoneetherketoneketone powder.

[0087] The second solvent is selected from organic solvents that can dissolve polyaryletherketone powder under heating conditions, such as sulfoxide solvents or alkane-ketone solvents, including but not limited to one of tetramethyl sulfoxide, diphenyl sulfone, dimethyl sulfoxide and N-methylpyrrolidone, preferably tetramethyl sulfoxide.

[0088] The positive electrode component is loaded onto the polyaryletherketone matrix material by using thermally induced phase separation, liquid blending technology and site occupancy method.

[0089] A porous structure is formed inside polyaryletherketone resin using thermally induced phase separation technology. Composite cathode materials are prepared by introducing cathode active materials, electrolytes, conductive agents and other cathode components using liquid blending technology and site-occupancy method. This method has low cost and a relatively simple preparation process.

[0090] Specifically, the technical principle of preparing polyaryletherketone (PAEK) materials by thermally induced phase separation is to dissolve PAEK in a suitable solvent at a temperature above its melting point to form a homogeneous solution. This solution is then rapidly poured into a mold for cooling. During cooling, the solubility of PAEK in the solvent gradually decreases, the system nucleates, and phase separation gradually occurs. Finally, after removing the solvent, a porous structure is formed inside the PAEK.

[0091] This invention uses polyetheretherketone (PEEK) as an example. PEEK is a type of polyaryletherketone material with excellent physical and chemical properties such as high strength, high temperature resistance, good chemical stability, and wear resistance. It is currently widely used in aerospace, automotive, electronics, and medical device fields. The preparation methods for PEEK materials can be mainly divided into physical methods and chemical methods. Physical methods mainly include supercritical fluid methods and thermally induced phase separation methods; while chemical methods mainly include chemical foaming agent methods and chemical etching methods.

[0092] The advantages of using thermally induced phase separation (TIPS) to prepare polyetheretherketone (PEEK) materials can be considered from several aspects. First, from a strength perspective, because TPS achieves phase separation of the polymer solution through more rapid heat exchange, the microstructure of the material is predominantly microporous, resulting in superior mechanical properties. Second, regarding porosity, the TPS preparation process is generally only affected by crystallization and liquid-liquid phase separation; therefore, almost all solvent molecules participate in the formation of the porous structure of polyetheretherketone, which is beneficial for the encapsulation of inorganic particles such as positive electrode active materials and conductive agents. Finally, from the perspective of cost and processing technology, the equipment and materials required for TPS are relatively inexpensive, and there are fewer influencing factors than other methods, making the processing technology of the composite material easier to control. Therefore, the preparation of composite positive electrode materials using TPS has good mechanical properties, low cost, simple method, and the product can adapt to the physical and chemical environment inside solid-state batteries.

[0093] Specifically, the positive electrode component dispersion formed in S1 is slowly poured into a homogenizer and thoroughly mixed with the polyaryletherketone matrix solution in S2 under heating conditions to form a homogenate. The current collector is spread evenly on a glass plate, and the glass plate is preheated to a certain temperature. Then, the mixture is poured onto the current collector while it is still hot, and a film is coated onto the surface of the current collector using a scraper. The heating device is removed, and after cooling to room temperature, the material is washed with the first and second washing solutions respectively, and then dried in a vacuum drying oven to obtain the polyaryletherketone-based composite positive electrode material.

[0094] The temperature at which the mixture is heated is 250-280°C, for example, any value between 250-280°C or any range between two values, such as 250°C, 260°C, 270°C and 280°C, for example, preferably 260-270°C.

[0095] The temperature of the preheated glass is 220-260℃, for example, any value or range between 220-260℃ such as 220℃, 230℃, 240℃, 250℃ and 260℃, for example, preferably 240-250℃.

[0096] The thickness of the coating during the coating process is 0.2-1mm, for example, any value between 0.2-1.0mm or any range between any two values, such as 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm and 1.0mm, for example, preferably 0.3-0.6mm.

[0097] The drying temperature is 80-100℃, and the time is 20-30 hours. For example, the drying temperature can be any value between 80-100℃ or any range between any two values, such as 80℃, 85℃, 90℃, 95℃, and 100℃. The drying time can be any value between 20-30 hours or any range between any two values, such as 20h, 21h, 22h, 23h, 24h, 25h, 26h, 27h, 28h, 29h, and 30h.

[0098] Current collectors include, but are not limited to, carbon-coated aluminum foil.

[0099] Thirdly, the present invention provides a battery comprising the composite cathode material described in the foregoing embodiments;

[0100] Preferably, the battery is a solid-state battery; more preferably, the battery is a solid-state lithium battery.

[0101] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0102] Example 1

[0103] This invention provides a method for preparing a polyetheretherketone-based composite cathode material, comprising:

[0104] Weigh 15g of lithium nickel cobalt manganese oxide (NCM811) and add it to 100mL of 99.5% ethanol solvent. Stir at high speed to uniformly disperse the solid, thus preparing a positive electrode active material dispersion solution. Add 3g of lithium aluminum titanium phosphate, 1.5g of conductive graphite, and 0.5g of polyvinylidene fluoride to the above dispersion solution in sequence, and then sonicate in an ultrasonic water bath to uniformly disperse the components. Stir at 200rpm for 2 hours to obtain the positive electrode component dispersion solution.

[0105] Add 180g of tetramethyl sulfoxide to a homogenizing tank, weigh 20g of polyetheretherketone powder and pour it into the homogenizing tank, stir at 200rpm, and heat to 270℃ at a heating rate of 10℃ / min. Maintain the temperature at 270℃ and stirring at 200rpm for 2 hours to obtain a polyetheretherketone matrix solution with a solid content of 10%.

[0106] The positive electrode component dispersion was slowly poured into the polyetheretherketone (PEEK) matrix solution and thoroughly mixed at 200 rpm. The mixture was heated to 270°C to remove the ethanol solvent, resulting in a PEEK matrix solution containing the positive electrode component. A 100mm x 100mm carbon-coated aluminum foil was then laid flat on a glass plate. The glass plate was heated to 240°C using a heating device. While still hot, the PEEK matrix solution containing the positive electrode component was quickly poured onto the carbon-coated aluminum foil. The solution was evenly coated onto the surface of the carbon-coated aluminum foil using a scraper, maintaining a thickness of 0.4mm. The heating device was removed, and after cooling to room temperature, the material was washed with appropriate amounts of N,N-dimethylformamide and sufficient anhydrous ethanol. After washing, the material was placed in a vacuum oven and dried at 90°C for 24 hours to form a PEEK-based composite positive electrode material.

[0107] Examples 2-7

[0108] Examples 2-7 describe the preparation of composite cathode materials using the method described in Example 1. The operational steps, conditions, and selection and proportioning of some materials are basically the same as in Example 1, except for the selection of the cathode components, as detailed below:

[0109] Example 2: The mass of NCM811 is 22.5g, and the masses of electrolyte LATP, conductive graphite and polyvinylidene fluoride are 4.5g, 2.25g and 0.75g, respectively.

[0110] Example 3: The mass of NCM811 is 30g, and the masses of LATP, conductive graphite and polyvinylidene fluoride are 6g, 3g and 1g, respectively.

[0111] Example 4: The mass of NCM811 is 7.5g, and the masses of LATP, conductive graphite and polyvinylidene fluoride are 1.5g, 0.75g and 0.25g, respectively.

[0112] Example 5: The mass of NCM811 is 24g, and the masses of LATP, conductive graphite, and polyvinylidene fluoride are 4g, 1.5g, and 0.5g, respectively.

[0113] Example 6: The mass of NCM811 is 25g, and the masses of LATP, conductive graphite, and polyvinylidene fluoride are 3.4g, 1.2g, and 0.4g, respectively.

[0114] Example 7: The mass of NCM811 is 22g, and the masses of LATP, conductive graphite, and polyvinylidene fluoride are 6g, 1.5g, and 0.5g, respectively.

[0115] Example 8 Example 15

[0116] Examples 8-15 describe the preparation of composite cathode materials using the method described in Example 5. The operational steps, conditions, some materials, and proportions are basically the same as in Example 5. The differences lie in the amount of the second solvent, the amount of polyetheretherketone, the coating thickness, or the selection of the cathode active material, as detailed below:

[0117] Example 8: The mass of tetramethyl sulfoxide is 140g.

[0118] Example 9: The mass of tetramethyl sulfoxide is 230g.

[0119] Example 10: The mass of tetramethyl sulfoxide is 270g, and the mass of polyetheretherketone is 30g.

[0120] Example 11: The mass of tetramethyl sulfoxide is 90g, and the mass of polyetheretherketone is 10g.

[0121] Example 12: The coating thickness is 0.5 mm.

[0122] Example 13: The coating thickness is 0.3 mm.

[0123] Example 14: The positive electrode active material is lithium nickel cobalt aluminum oxide.

[0124] Example 15: The positive electrode active material is lithium manganese oxide.

[0125] Comparative Example 1

[0126] This comparative example provides a method for preparing a cathode material, including:

[0127] Weigh 24g of lithium nickel cobalt manganese oxide (NCM811) and add it to 100mL of 99.5% ethanol solvent. Stir at high speed to uniformly disperse the solid, thus preparing a positive electrode active material dispersion solution. Add 4g of lithium aluminum titanium phosphate, 1.5g of conductive graphite, and 0.5g of polyvinylidene fluoride to the above dispersion solution in sequence, and then sonicate in an ultrasonic water bath to uniformly disperse the two components. Stir at 200rpm for 2 hours to obtain the positive electrode component dispersion solution.

[0128] 180g of tetramethyl sulfoxide was added to a homogenizing vessel and stirred at 200rpm. The mixture was heated to 270℃ at a heating rate of 10℃ / min. The mixture was maintained at 270℃ and 200rpm for 2 hours. The positive electrode component dispersion was then slowly poured into the solution and stirred thoroughly at 200rpm until homogeneous. The ethanol solvent was removed while maintaining the heating temperature at 270℃, resulting in a solution containing the positive electrode component. A 100mm x 100mm carbon-coated aluminum foil was then laid flat on a glass plate. The glass plate was heated to 240℃ using a heating device. While still hot, the solution containing the positive electrode component was quickly poured onto the carbon-coated aluminum foil. The solution was then evenly coated onto the surface of the aluminum foil using a spatula, maintaining a thickness of 0.4mm. After removing the heating device and allowing it to cool to room temperature, wash it with an appropriate amount of N,N-dimethylformamide and sufficient anhydrous ethanol. After washing, place the material in a vacuum oven and dry it at 90°C for 24 hours to obtain a positive electrode material that does not contain polyether ether ketone.

[0129] Comparative Example 2

[0130] This comparative example provides a method for preparing a cathode material, including:

[0131] Weigh 24g of lithium nickel cobalt manganese oxide (NCM811) and add it to 100mL of 99.5% ethanol solvent. Stir at high speed to uniformly disperse the solid, thus preparing a positive electrode active material dispersion solution. Add 4g of lithium aluminum titanium phosphate, 1.5g of conductive graphite, and 0.5g of polyvinylidene fluoride to the above dispersion solution in sequence, and then sonicate in an ultrasonic water bath to uniformly disperse the two components. Stir at 200rpm for 2 hours to obtain the positive electrode component dispersion solution.

[0132] Add 180g of N-methylpyrrolidone (NMP) to a homogenizing tank, weigh out 1.5g of polyvinylidene fluoride (PVDF), 3.5g of polyvinylidene fluoride hexafluoropropylene (PVDFHFP), and 5g of polyvinylpyrrolidone (PVP), and pour them into the homogenizing tank. Stir at 200 rpm for 2 hours to obtain a matrix solution with a solid content of 10%.

[0133] The cathode component dispersion was slowly poured into the matrix solution and thoroughly mixed at 200 rpm. The mixture was heated to 80°C to remove the ethanol solvent, resulting in a matrix solution containing the cathode component. A 100mm x 100mm carbon-coated aluminum foil was then laid flat on a glass plate. The glass plate was heated to 100°C using a heating device. While still hot, the matrix solution containing the cathode component was quickly poured onto the carbon-coated aluminum foil. The solution was then evenly coated onto the surface of the aluminum foil using a scraper, maintaining a thickness of 0.4mm. The heating device was removed, and after cooling to room temperature, the material was washed with an appropriate amount of anhydrous ethanol. After washing, the material was placed in a vacuum oven and dried at 90°C for 24 hours to obtain a porous composite cathode material crosslinked with PVDF and PVDF HFP.

[0134] Comparative Example 3

[0135] This comparative example provides a method for preparing a cathode material, including:

[0136] Weigh 24g of lithium nickel cobalt manganese oxide (NCM811), 4g of lithium aluminum titanium phosphate, 1.5g of conductive graphite and 0.5g of polyvinylidene fluoride, and add them to a ball mill jar in sequence. Then, ball mill the mixture to ensure that the three components are mixed evenly. Stir at 350 rpm for 0.5 hours to obtain a uniformly mixed cathode component powder. Use a scraper to evenly coat the powder onto the surface of carbon-coated aluminum foil, controlling the thickness to 0.4mm, to obtain a cathode material that does not contain polyether ether ketone.

[0137] Comparative Example 4

[0138] This comparative example provides a method for preparing a cathode material, including:

[0139] The polyether ether ketone-based composite cathode material prepared in Example 5 was placed on a press and compacted with a pressure of 100 MPa to obtain a polyether ether ketone-based composite cathode material without porous structure.

[0140] Comparative Example 5

[0141] This comparative example provides a method for preparing a cathode material, including:

[0142] Add 180g of tetramethyl sulfoxide to a homogenizing tank, weigh 20g of polyetheretherketone powder and pour it into the homogenizing tank, stir at 200rpm, and heat to 270℃ at a heating rate of 10℃ / min. Maintain the temperature at 270℃ and stirring at 200rpm for 2 hours to obtain a polyetheretherketone matrix solution with a solid content of 10%.

[0143] A 100mm x 100mm carbon-coated aluminum foil was laid flat on a glass plate. The glass plate was heated to 240℃ using a heating device. While still hot, a polyetheretherketone (PEEK) matrix solution was quickly poured onto the carbon-coated aluminum foil. The solution was then evenly coated onto the surface of the aluminum foil using a scraper, maintaining a thickness of 0.4mm. The heating device was removed, and after cooling to room temperature, the material was cleaned with appropriate amounts of N,N-dimethylformamide and sufficient anhydrous ethanol. After cleaning, the material was placed in a vacuum oven and dried at 90℃ for 24 hours to obtain a PEEK composite material free of positive electrode components.

[0144] Comparative Example 6

[0145] This comparative example provides a method for preparing a cathode material, including:

[0146] Weigh 24g of lithium cobalt oxide (LCO) and add it to 100mL of 99.5% ethanol solvent. Stir at high speed to uniformly disperse the solid, thus preparing a positive electrode active material dispersion solution. Add 4g of lithium aluminum titanium phosphate, 1.5g of conductive graphite, and 0.5g of polyvinylidene fluoride to the above dispersion solution in sequence, and then sonicate in an ultrasonic water bath to uniformly disperse the two components. Stir at 200rpm for 2 hours to obtain the positive electrode component dispersion solution.

[0147] Add 180g of tetramethyl sulfoxide to a homogenizing tank, weigh 20g of polyetheretherketone powder and pour it into the homogenizing tank, stir at 200rpm, and heat to 270℃ at a heating rate of 10℃ / min. Maintain the temperature at 270℃ and stirring at 200rpm for 2 hours to obtain a polyetheretherketone matrix solution with a solid content of 10%.

[0148] The positive electrode component dispersion was slowly poured into the polyetheretherketone (PEEK) matrix solution and thoroughly mixed at 200 rpm. The mixture was heated to 270°C to remove the ethanol solvent, resulting in a PEEK matrix solution containing the positive electrode component. A 100mm x 100mm carbon-coated aluminum foil was then laid flat on a glass plate. The glass plate was heated to 240°C using a heating device. While still hot, the PEEK matrix solution containing the positive electrode component was quickly poured onto the carbon-coated aluminum foil. The solution was evenly coated onto the surface of the carbon-coated aluminum foil using a scraper, maintaining a thickness of 0.4mm. The heating device was removed, and after cooling to room temperature, the material was washed with appropriate amounts of N,N-dimethylformamide and sufficient anhydrous ethanol. After washing, the material was placed in a vacuum oven and dried at 90°C for 24 hours to form a PEEK-based composite positive electrode material.

[0149] Characterization

[0150] The morphology of the cathode materials of Example 1 and Comparative Example 5 was characterized, and the results are shown in [reference]. Figures 2 to 3 .

[0151] according to Figure 2 and Figure 3 It can be seen that the positive electrode component is uniformly dispersed on the porous structure of the polyetheretherketone matrix.

[0152] Meanwhile, the embodiments of the present invention provide Figure 2 This demonstrates that the embodiments of the present invention form a porous structure inside the polyaryletherketone resin through thermally induced phase separation technology, and introduce positive electrode components such as positive electrode active material, electrolyte, and conductive agent by liquid blending technology and site occupation method.

[0153] Battery assembly

[0154] The molded battery was assembled in a glove box. The protective gas inside the glove box was argon, and the partial pressures of water and oxygen were both below 0.1 ppm. Die-cut solid-state battery composite positive electrode material was selected, with LATP as the solid electrolyte and lithium metal as the negative electrode. All components were pressed at a pressure of 10 MPa to assemble a solid-state battery.

[0155] Battery test

[0156] With a cutoff voltage of 2.5–4.0V, the system was charged and discharged at a rate of 0.5C for 100 cycles. The initial discharge specific capacity, initial coulombic efficiency, and capacity retention rate after 100 cycles were recorded. The results are shown in Table 1.

[0157] Table 1. Initial discharge specific capacity, initial coulombic efficiency, and capacity retention after 100 cycles for coin cells.

[0158]

[0159]

[0160] As shown in Table 1, using the composite cathode material provided in the embodiments of the present invention can significantly improve battery performance. This is attributed to the combined effect of the porous structure and mechanical properties of the polyetheretherketone (PEEK) material. The porous structure of PEEK provides sufficient space for the cathode active material to alleviate its volume expansion, thereby maintaining a stable battery capacity and giving it good cycle stability. Simultaneously, the high mechanical strength and good flexibility of the PEEK-based composite cathode material can reduce the risk of short circuits during cycling, improving battery safety.

[0161] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A composite cathode material, characterized in that, It includes a polyaryletherketone matrix material with a porous structure and a positive electrode component, wherein the positive electrode component is loaded on the polyaryletherketone matrix material; the positive electrode component is attached to the porous structure of the polyaryletherketone matrix material.

2. The composite cathode material according to claim 1, characterized in that, The polyaryletherketone matrix material is selected from any one of polyetheretherketone matrix materials, polyetherketone matrix materials, polyetherketone ketone matrix materials, polyetheretherketone ketone matrix materials, and polyetherketone etherketone ketone matrix materials.

3. The composite cathode material according to claim 1 or 2, characterized in that, The positive electrode component includes any one or a combination of two or more of the following: positive electrode active material, electrolyte, conductive agent, and binder.

4. The composite cathode material according to claim 3, characterized in that, The positive electrode active material includes materials containing one or more of nickel, cobalt and manganese; The conductive agent is selected from carbon-containing materials. The adhesive is selected from polymers.

5. The composite cathode material according to claim 3, characterized in that, The positive electrode active material includes one or more of lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium manganese oxide, lithium nickel manganese oxide, lithium cobalt manganese oxide, lithium-rich manganese-based materials, and nickel manganese spinel. The conductive agent is selected from carbon black and graphite materials; The binder is any one of ester polymers, amine polymers, and olefin polymers.

6. The composite cathode material according to claim 3, characterized in that, The conductive agent is at least one selected from conductive graphite, conductive carbon black, acetylene black, carbon nanotubes, and carbon nanofibers. The adhesive is at least one of polyvinylidene fluoride, polyimide, and polyacrylate.

7. The composite cathode material according to claim 3, characterized in that, The conductive agent is conductive graphite; the binder is polyvinylidene fluoride.

8. The composite cathode material according to claim 3, characterized in that, The positive electrode active material is selected from inorganic particles.

9. The composite cathode material according to claim 3, characterized in that, The positive electrode active material is a basic phosphate salt.

10. The composite cathode material according to claim 3, characterized in that, The positive electrode active material is an aluminum titanium phosphate basic salt.

11. A method for preparing the composite cathode material according to claim 1, characterized in that, include: The positive electrode component is loaded onto the polyaryletherketone matrix material; Specifically, this includes: preparing a dispersion of positive electrode components; Preparation of polyaryletherketone matrix solutions containing polyaryletherketone; The positive electrode component is loaded onto the polyaryletherketone matrix material by using thermally induced phase separation, liquid blending technology and site occupancy method.

12. The preparation method according to claim 11, characterized in that, include: Prepare a dispersion of positive electrode components containing positive electrode components.

13. The preparation method according to claim 11, characterized in that, The steps for forming the positive electrode component dispersion include: mixing the first solvent, positive electrode active material, electrolyte, conductive agent and binder evenly.

14. The preparation method according to claim 13, characterized in that, The steps for forming the positive electrode component dispersion include: mixing the first solvent and the positive electrode active material evenly, and then mixing them evenly with the conductive agent and the binder in sequence.

15. The preparation method according to any one of claims 12-14, characterized in that, The conditions for the mixing process include: a rotation speed of 200~500 rpm and a time of 2~3 h.

16. The preparation method according to claim 13, characterized in that, The first solvent is selected from alcohol solvents, and the positive electrode active material includes materials containing any one or more combinations of nickel, cobalt and manganese; The conductive agent is selected from carbon-containing materials. The adhesive is selected from polymers.

17. The preparation method according to claim 13, characterized in that, The first solvent is selected from monohydric alcohols; the positive electrode active material includes one or more of lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium manganese oxide, lithium nickel manganese oxide, lithium cobalt manganese oxide, lithium-rich manganese-based materials, and nickel manganese spinel; The conductive agent is selected from carbon black and graphite materials; The binder is any one of ester polymers, amine polymers, and olefin polymers.

18. The preparation method according to claim 13, characterized in that, The first solvent is selected from C1-C10 monohydric alcohols; the conductive agent is at least one selected from conductive graphite, conductive carbon black, acetylene black, carbon nanotubes, and carbon nanofibers. The adhesive is at least one of polyvinylidene fluoride, polyimide, and polyacrylate.

19. The preparation method according to claim 13, characterized in that, The first solvent is selected from C1-C5 monohydric alcohols, the conductive agent is conductive graphite, and the binder is polyvinylidene fluoride.

20. The preparation method according to claim 13, characterized in that, The first solvent is selected from any one or a combination of two or more of methanol, ethanol, propanol, propylene glycol, glycerol, ethylene glycol and isopropanol.

21. The preparation method according to claim 13, characterized in that, The positive electrode active material is selected from inorganic particles.

22. The preparation method according to claim 13, characterized in that, The positive electrode active material is a basic phosphate salt.

23. The preparation method according to claim 13, characterized in that, The positive electrode active material is an aluminum titanium phosphate basic salt.

24. The preparation method according to claim 13, characterized in that, The positive electrode active material accounts for 65-85% of the total mass of the positive electrode component dispersion, the electrolyte accounts for 10-25% of the total mass of the positive electrode component dispersion, the conductive agent accounts for 3-10% of the total mass of the positive electrode component dispersion, the binder accounts for 1-10% of the total mass of the positive electrode component dispersion, and the mass concentration of the first solvent is 80%~99.9%.

25. The preparation method according to claim 13, characterized in that, The mass of the positive electrode active material accounts for 70-80% of the total mass of the positive electrode component dispersion; The electrolyte accounts for 15-20% of the total mass of the positive electrode component dispersion; The conductive agent accounts for 3-9% of the total mass of the positive electrode component dispersion; The binder accounts for 1-5% of the total mass of the positive electrode component dispersion; The mass concentration of the first solvent is 95%~99.5%.

26. The preparation method according to claim 11, characterized in that, The preparation steps of the polyaryletherketone matrix solution include: mixing and dissolving the second solvent and the polyaryletherketone powder.

27. The preparation method according to claim 26, characterized in that, The conditions for the dissolution process include: temperature of 250-280℃, rotation speed of 200-500 rpm, and time of 1-3 hours; The solid content of the polyaryletherketone matrix solution is 5-20%; The melt index of the polyaryletherketone powder is 8-15; The second solvent is selected from sulfoxide solvents or alkyl ketone solvents. The polyaryletherketone powder is selected from any one of polyetheretherketone powder, polyetherketone powder, polyetherketone ketone powder, polyetheretherketone ketone powder, and polyetherketone etherketone ketone powder.

28. The preparation method according to claim 26, characterized in that, The conditions for the dissolution process include a temperature of 260-270℃; The solid content of the polyaryletherketone matrix solution is 5-15%; The second solvent is selected from one of tetramethyl sulfoxide, diphenyl sulfone, dimethyl sulfoxide, and N-methylpyrrolidone.

29. The preparation method according to claim 11, Its features are, This includes: mixing a dispersion of a positive electrode component containing a positive electrode component and a polyaryletherketone matrix solution containing a polyaryletherketone under heating conditions to form a mixture; Preheat the current collector, and then coat the current collector with the mixture; Next, cooling, washing, and drying are carried out.

30. The preparation method according to claim 29, characterized in that, The heating temperature is 250-280℃, the preheating temperature is 220-260℃, and the thickness of the coated film is 0.2-1mm; the drying conditions include: drying temperature of 80-100℃ and drying time of 20-30 h.

31. The preparation method according to claim 29, characterized in that, The heating temperature is 260-270℃; the preheating temperature is 240-250℃; and the thickness of the coated film is 0.3-0.6mm.

32. A battery, characterized in that, It includes the composite cathode material as described in claim 1.

33. The battery according to claim 32, characterized in that, The battery is a solid-state battery.

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