Lithium-ion solid-state battery electrode and its preparation method

Abstract

The present invention provides a lithium-ion solid-state battery electrode material and a preparation method thereof. The steps of the preparation method include adding a nitrogen source and a carboxyl auxiliary ligand to a metal salt solution, carrying out a thermal synthesis reaction to obtain a coordinated metal cluster; mixing a cellulose derivative and a functional organic group, carrying out a polymerization reaction to obtain a copolymer matrix; dissolving the coordinated metal cluster and the copolymer matrix in a lithium salt solution, carrying out a crosslinking reaction to obtain a composite solution; adding an electrode active material to the composite solution, stirring evenly, defoaming, and then coating it on a current collector, and drying to obtain the lithium-ion solid-state battery electrode material. Thereby, the cycle life and the conduction efficiency of the battery are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of battery materials, and particularly relates to a lithium-ion solid-state battery electrode and a preparation method thereof. Background Art

[0002] A lithium-ion solid-state battery is a lithium-ion battery that uses a solid electrolyte instead of a traditional liquid electrolyte. Compared with liquid batteries, solid-state batteries have higher safety, energy density, and longer cycle life. The electrolyte of a solid-state battery is usually a ceramic or polymer material, which can work in a wider temperature range and does not face the risk of leakage or combustion like liquid batteries.

[0003] In some special applications, lithium-ion solid-state batteries need to work in environments with high salt concentration or high humidity. These environments pose challenges to the material properties, long-term stability, and lifespan of the battery, so the battery is required to withstand extreme conditions. For example, in ocean research or subsea exploration equipment, such as deep-sea ocean detectors, underwater robots, subsea sensors, etc. The salt water in the ocean environment has strong corrosiveness, and the battery must have sufficient corrosion resistance and long-term stability to continuously work in such an environment. However, in related technologies, the interface between the electrode materials of lithium-ion solid-state batteries is affected by moisture or salt, resulting in an increase in interface impedance, thereby reducing the overall conductivity of the battery and leading to a decrease in the conductive efficiency and lifespan of the battery. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a lithium-ion solid-state battery electrode and a preparation method thereof, aiming to solve the problems of decreased battery lifespan and conductive efficiency.

[0005] To solve the above technical problem, the present invention is implemented as follows. A preparation method of a lithium-ion solid-state battery electrode is proposed, and the steps include:

[0006] S1. Add a nitrogen source and a carboxyl auxiliary ligand to a metal salt solution, and carry out a thermal reaction to obtain a coordinated metal cluster;

[0007] S2. Mix a cellulose derivative and a functional organic group, and carry out a polymerization reaction to obtain a copolymer matrix;

[0008] S3. Dissolve the coordinated metal cluster and the copolymer matrix in a lithium salt solution, and carry out a cross-linking reaction to obtain a composite solution;

[0009] S4. Add an electrode active material to the composite solution, stir evenly and then defoam to obtain a slurry of a lithium-ion solid-state battery electrode material. Then, coat the slurry of the lithium-ion solid-state battery electrode material on a current collector, and dry to obtain a lithium-ion solid-state battery electrode.

[0010] In some embodiments of the present invention, in the step S1, the nitrogen source includes at least one of imidazoline, pyridine, and ethylenediamine, the carboxyl auxiliary ligand includes at least one of terephthalic acid, oxalic acid, and acetic acid, and the metal salt solution includes at least one of copper(II) nitrate, zinc(II) nitrate, and cobalt(II) chloride.

[0011] In some embodiments of the present invention, by mass ratio, the nitrogen source: the carboxyl auxiliary ligand: the metal salt solution = 1 - 3:1:1.

[0012] In some embodiments of the present invention, the step S1 includes:

[0013] S1.1. Dissolve the selected metal salt in absolute ethanol or water, and stir until completely dissolved to obtain a metal salt solution;

[0014] S1.2. Add the nitrogen source and the carboxyl auxiliary ligand to the metal salt solution, heat up to 50 - 60 °C, and stir until completely dissolved;

[0015] S1.3. Heat up to 70 - 80 °C, keep warm for 2 - 6 h, naturally cool after the heat preservation ends, and then filter and dry to obtain a coordination metal cluster.

[0016] In some embodiments of the present invention, the step S2 includes:

[0017] S2.1. Dissolve the cellulose derivative in water or absolute ethanol, and use a magnetic stirrer to stir at room temperature to ensure that the cellulose derivative is completely dissolved to obtain a cellulose derivative solution;

[0018] S2.2. Add the functional organic group solution to the cellulose solution, add a dispersant while stirring, and stir for 20 - 30 min to obtain a mixed solution;

[0019] S2.3. Add an initiator to the mixed solution, carry out a polymerization reaction at a temperature of 60 - 80 °C for a reaction time of 4 - 6 h, keep stirring during the reaction, after the reaction is completed, filter to remove unreacted monomers and impurities, and dry to obtain a copolymer matrix.

[0020] In some embodiments of the present invention, in step S2, the cellulose derivative includes at least one of cellulose ether, cellulose acetate, and cellulose ester, the functional organic group includes at least one of acrylate group, imidazoline group, and acrylic functional group, the initiator includes at least one of sodium persulfate, hydrogen peroxide, and diphenyl peroxide, and the dispersant includes at least one of polyvinylpyrrolidone, sodium dodecylbenzenesulfonate, and polyvinyl alcohol.

[0021] In some embodiments of the present invention, calculated by mass ratio, the functional organic group: the cellulose derivative = 1:4 to 10.

[0022] In some embodiments of the present invention, step S3 includes:

[0023] S3.1. First, dissolve the coordination metal cluster in a solvent, stir in a temperature-controlled stirrer to ensure the solution is uniform, and control the reaction temperature at 50 to 70 °C to obtain a coordination metal cluster solution, wherein the solvent includes at least one of anhydrous ethanol, dimethyl sulfoxide, and N,N-dimethylformamide;

[0024] S3.2. Dissolve the copolymer matrix in anhydrous ethanol or acetone, use a heating stirrer to maintain the temperature between 50 and 60 °C to obtain a copolymer solution, and then add the coordination metal cluster solution to the copolymer solution and stir for 1 to 2 h to obtain a composite solution.

[0025] In some embodiments of the present invention, in step S4, the electrode active material includes a positive electrode active material or a negative electrode active material. The positive electrode active material includes at least one of lithium cobaltate, lithium iron phosphate, and nickel-rich ternary materials. The negative electrode active material includes at least one of graphite, silicon-based materials, and lithium metal. The current collector includes a positive electrode current collector or a negative electrode current collector. The positive electrode current collector includes at least one of aluminum foil, nickel foil, and titanium foil. The negative electrode current collector includes at least one of copper foil, stainless steel foil, and nickel foil.

[0026] The present invention provides a lithium-ion solid-state battery electrode, which is characterized in that it is made by the preparation method of a lithium-ion solid-state battery electrode as described above. The lithium-ion solid-state battery electrode includes a lithium-ion solid-state battery electrode material, and the lithium-ion solid-state battery electrode material includes a coordination metal cluster, a copolymer matrix, and a lithium salt; wherein,

[0027] The coordination metal cluster is used to enhance the conductivity, stability of the lithium-ion solid-state battery electrode material, and the interaction with lithium ions;

[0028] The copolymer matrix is used to provide structural support, enhance mechanical strength, and assist lithium ion transport;

[0029] The lithium salt is used to provide a lithium ion source and promote ionic conductivity.

[0030] Compared with the prior art, the beneficial effects of the lithium-ion solid-state battery electrode and its preparation method in the present invention are as follows:

[0031] The preparation process of the coordination metal cluster involves reacting a nitrogen source and a carboxyl auxiliary ligand with a metal salt solution. The resulting metal cluster has high stability and good electronic conductivity. These metal clusters can enhance the electron conduction ability of the electrode material and reduce the conductance loss of the battery in high-salinity and high-humidity environments. In a high-salt concentration environment, the stability of the coordination metal cluster helps prevent corrosion inside the battery, while the good conductivity enables the battery to maintain high performance in extreme environments. The copolymer matrix of cellulose derivatives and functional organic groups has excellent structural support and mechanical strength. The copolymer matrix provides the framework for the electrode material, and its structure can effectively resist the influence of moisture in a high-humidity environment. The solid electrolyte obtained through a cross-linking reaction is not easily affected by moisture in a high-humidity environment, ensuring that the ionic conductivity of the battery is not affected by moisture. In addition, solid electrolytes usually have high electrochemical stability and salt corrosion resistance, enabling the electrolyte to maintain high conductivity and stability in a high-salinity environment.

[0032] Therefore, in a high-salt concentration environment, the electrode material of the lithium-ion solid-state battery can avoid common problems such as corrosion or lithium plating caused by salts in liquid batteries. The anti-corrosion properties of the coordination metal cluster and the solid electrolyte can ensure that the battery still maintains good ionic conductivity in a high-salt environment and improve the power density and efficiency of the battery. In a high-humidity environment, the solid electrolyte can effectively reduce the influence of moisture on the battery. The solid electrolyte material obtained through a cross-linking reaction has good moisture isolation and mechanical stability, avoiding the problem of electrolyte degradation caused by moisture penetration and improving the cycle life and conduction efficiency of the battery. Brief Description of the Drawings

[0033] Figure 1 It is a schematic flowchart of a method for preparing an electrode material of a lithium-ion solid-state battery according to an embodiment of the present invention. Detailed Embodiments

[0034] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0035] Please refer to Figure 1 , the present invention provides a method for preparing an electrode material of a lithium-ion solid-state battery, and the steps include:

[0036] S1. Add the nitrogen source and carboxyl auxiliary ligand to the metal salt solution and carry out a thermal reaction to obtain a coordination metal cluster. In step S1, the nitrogen source includes at least one of imidazoline, pyridine, and ethylenediamine, the carboxyl auxiliary ligand includes at least one of terephthalic acid, oxalic acid, and acetic acid, and the metal salt solution includes at least one of copper(II) nitrate, zinc(II) nitrate, and cobalt(II) chloride.

[0037] Calculated by mass ratio, nitrogen source: carboxyl auxiliary ligand: metal salt solution = 1 - 3:1:1.

[0038] Step S1 includes:

[0039] S1.1. Dissolve the selected metal salt in absolute ethanol or water and stir until completely dissolved to obtain a metal salt solution.

[0040] By dissolving the metal salt, it ensures that metal ions are evenly distributed in the solution, laying the foundation for subsequent coordination reactions. Absolute ethanol or water is a common solvent that can effectively dissolve most metal salts and has good compatibility with the dissolution of the nitrogen source and carboxyl auxiliary ligand, ensuring the smooth progress of subsequent reactions. The dissolution process helps to form a stable coordination metal cluster when the metal salt reacts with the ligand, optimizing the release and reaction activity of metal ions.

[0041] S1.2. Add the nitrogen source and carboxyl auxiliary ligand to the metal salt solution, heat up to 50 - 60 °C, and stir until completely dissolved.

[0042] By adding the nitrogen source (such as imidazoline, pyridine, ethylenediamine) and carboxyl auxiliary ligand (such as terephthalic acid, oxalic acid, acetic acid), they provide coordination sites, which helps metal ions form coordination compounds with these ligands to form a stable coordination metal cluster.

[0043] Heating the solution to 50 - 60 °C helps to accelerate the dissolution of the nitrogen source and carboxyl ligand and their coordination reaction with metal ions. The control of temperature ensures an appropriate reaction rate and avoids unnecessary side reactions caused by too high temperature. This temperature range helps the coordination reaction of the nitrogen source and ligand with metal ions to be more rapid and complete, ensuring the formation of the coordination metal cluster.

[0044] S1.3. Heat up to 70 - 80 °C, keep warm for 2 - 6 h, after the heat preservation ends, cool naturally and then filter and dry to obtain the coordination metal cluster.

[0045] Heating up to 70 - 80 °C and keeping warm for 2 - 6 hours can promote the completion of the coordination reaction, enabling metal ions and ligands to fully react to form a stable coordination metal cluster. This temperature range helps to increase the stability of the coordination metal cluster and at the same time prevents adverse side reactions caused by too high temperature.

[0046] Through a long-term heat preservation reaction, the complete formation of metal clusters is ensured, and it helps to remove by-products in the reaction. The filtration and drying processes after cooling help to obtain pure coordination metal clusters, avoid the residue of unreacted substances, and ensure the purity and performance of the final product. During this process, the reaction conditions (temperature, time, etc.) can regulate the particle size and morphology of the coordination metal clusters, thereby affecting their electrochemical properties, such as improving ionic conductivity and stability.

[0047] During the heating process, the particle size of the coordination metal clusters can be controlled by controlling the temperature, according to , where is the reaction rate of the heating process, is the reaction rate constant of the heating process, is the activation energy of the heating reaction, is the gas constant, which is 8.314 J / (mol·K), is the real-time temperature. This equation shows that an increase in temperature will accelerate the reaction rate, thereby increasing the growth rate of the coordination metal clusters. Controlling the reaction temperature can prevent the over-aggregation of the coordination metal clusters. The activation energy of the heating reaction is the minimum energy required to carry out the reaction, and it characterizes the energy required for the reactants to overcome the reaction barrier. The higher the activation energy, the slower the rate of increase of the reaction rate constant at high temperatures. The activation energy is obtained through the Arrhenius equation. By experimentally measuring the reaction rate constants at different temperatures, and then performing a linear fit to obtain the slope ( ), the activation energy can thus be calculated.

[0048] The growth of the coordination metal clusters conforms to the nanoparticle growth theory, and its growth process is controlled by the following equation:

[0049]

[0050] where, is the radius of the coordination metal clusters; is the reaction rate constant dependent on temperature and concentration, is the initial concentration of the metal salt, is the concentration of metal ions during the reaction process, is the heat preservation time.

[0051] According to the above equation, can be inferred as , where, is the pre-exponential factor, is the metal salt concentration, is the influence index of concentration, and its value can range from 0.8 to 1. The pre-exponential factor is a constant of the reaction rate constant, which is related to the collision frequency of reactants and the geometric arrangement of reactants. It is an empirical constant obtained through experimental data. Its unit is usually consistent with the unit of the reaction rate and is independent of temperature. By using the Arrhenius equation to fit the reaction rate constant and temperature with multiple sets of reaction rate constant data at different temperatures, the pre-exponential factor can be obtained. is 10 5 ~10 13 , and the specific value needs to be obtained through experimental data.

[0052] To simplify the model, we assume that the change in metal ion concentration is small in the initial reaction, and can be approximated as .

[0053] Therefore, the equation is simplified to: , is the time when the particle size of the coordinated metal cluster, is the initial particle size, which is obtained by measuring the average particle size of the coordinated metal cluster in step S1.2. This equation shows that the growth rate of the coordinated metal cluster is related to the temperature and the metal salt concentration . An increase in temperature will accelerate the growth of the coordinated metal cluster. Excessively high temperature may lead to excessive growth of particles, resulting in uncontrolled particle size and the formation of larger metal clusters. This will reduce the specific surface area of the material and thus affect the performance of the battery, especially the conductivity and the efficiency of lithium ion insertion / extraction. A higher concentration will promote the rapid growth of the coordinated metal cluster, resulting in a larger particle size.

[0054] Coordinated metal clusters with smaller particle sizes have a higher specific surface area, which means they can provide more active sites for lithium ion insertion and extraction. A higher specific surface area can usually enhance the capacity of the electrode material because more lithium ions can participate in the charge and discharge process of the battery. By increasing the surface area of the coordinated metal cluster, the specific capacity of the electrode material can be improved.

[0055] The small particle size of the coordinated metal cluster means that they can form a more uniform conductive network. Small-sized coordinated metal clusters can usually reduce the obstacles to electron conduction, thereby improving the electronic conductivity of the electrode material. Smaller particle sizes can help the battery perform better at high current densities because they can conduct electrons faster. Improving the electronic conductivity of the electrode material, especially having an advantage during high-rate charge and discharge, reduces the resistance loss of the battery during rapid charge and discharge.

[0056] Smaller coordinated metal clusters have more surface sites, allowing lithium ions to be inserted and extracted more rapidly, thus improving the charge and discharge rates of the battery. This is particularly important for high power density applications such as electric vehicles and fast charging devices. Improve the charge and discharge rates of the electrode material to make it more efficient under fast charge and discharge conditions.

[0057] During the charge and discharge process, lithium ions are inserted and extracted in the electrode material, causing volume changes in the material. Small-sized coordinated metal clusters can alleviate volume expansion and reduce structural damage to the electrode material during long-term use. Compared with larger particles, smaller particles are structurally more stable and less prone to fragmentation or swelling problems. Enhance the cycle stability of the electrode material and extend the service life of the battery.

[0058] Controlling the particle size of the coordinated metal clusters helps to improve the stability of the coordinated metal clusters and prevent aggregation or agglomeration during the charge and discharge process. Coordinated metal clusters with smaller particle sizes are usually more dispersed, reducing the loss of surface active sites and improving the long-term stability of the coordinated metal clusters in the electrode material. Enhance the electrochemical stability of the battery material and reduce capacity decay caused by particle aggregation during cycling.

[0059] Coordinated metal clusters with small particle sizes have stronger reactivity and can more easily participate in the lithium ion migration and reactions in the battery. Therefore, the electrode material exhibits better reactivity and selectivity during the charge and discharge process, improving the overall efficiency of the battery. Enhance the ion selectivity and reaction activity of the electrode material, thereby increasing the energy density and efficiency of the battery.

[0060] Smaller coordinated metal clusters help the material maintain good thermal stability during operation. Under high temperature conditions, coordinated metal clusters with smaller particle sizes are less likely to overheat or fail, thus improving the thermal stability of the battery. Enhance the thermal stability of the battery, improve its adaptability under different environmental conditions, and avoid battery overheating and performance degradation.

[0061] The particle size of the coordinated metal clusters can be controlled within the range of 5 - 20 nm. This particle size range can provide a large specific surface area, thereby increasing the capacity of the electrode while ensuring the cycle stability and high ion conductivity of the battery. Control the particle size of the coordinated metal clusters by reducing the temperature or the solubility of the metal salt solution. For example, add an appropriate amount of solvent (such as anhydrous ethanol, dimethyl sulfoxide (DMSO), water, etc.) to the original metal salt solution to reduce the concentration of the metal salt. By diluting with the solvent, the concentration of the metal salt can be made to meet the required range. Or use a standardized metal salt solution with a known concentration and dilute it to the required concentration according to the required ratio. Or evaporate the solvent in a low-temperature vacuum environment. A rotary evaporator or other evaporation equipment can be used to remove the solvent. After evaporating to an appropriate volume, add solvent to the solution according to the need and dilute it to the target concentration.

[0062] S2. Mixing the cellulose derivative and the functional organic group, performing a polymerization reaction, and obtaining a copolymer matrix.

[0063] S2.1. Dissolve a cellulose derivative in water or anhydrous ethanol, and stir with a magnetic stirrer at room temperature to ensure that the cellulose derivative is completely dissolved to obtain a cellulose derivative solution; the cellulose derivative includes at least one of cellulose ether, cellulose acetate, and cellulose ester.

[0064] By dissolving the cellulose derivative, a uniform solution can be obtained. This provides a good foundation for the subsequent polymerization reaction, allowing the cellulose derivative to fully contact the functional organic groups. Continuous stirring with a magnetic stirrer at room temperature can ensure that the cellulose derivative is completely dissolved in the solution, thereby increasing its reactivity and promoting the smooth progress of subsequent reactions. Water or anhydrous ethanol as a solvent can not only effectively dissolve the cellulose derivative, but also provide a suitable environment for subsequent reactions with functional organic groups. Anhydrous ethanol can help dissolve more hydrophobic cellulose derivatives.

[0065] S2.2. Add the functional organic group solution to the cellulose solution while stirring. Add a dispersant and stir for 20-30 minutes to obtain a mixed solution. The functional organic group includes at least one of an acrylate group, an imidazoline group, and an acrylic functional group. The dispersant includes at least one of polyvinyl pyrrolidone, sodium dodecylbenzenesulfonate, and polyvinyl alcohol. The weight ratio of functional organic group to cellulose derivative is 1:4-10.

[0066] Functional organic groups are added to the cellulose solution, and it is ensured that these groups are evenly dispersed in the solution. The introduction of functional groups gives the final copolymer material special functional properties such as ionic conductivity and coordination ability. By adding a dispersant, the functional groups and cellulose derivatives can be effectively dispersed, the agglomeration of polymers or groups can be avoided, and the uniformity of the reaction can be ensured. The dispersant can optimize the reaction system and improve the stability and performance of the material. Stirring for 20 to 30 minutes ensures that the functional organic groups and cellulose derivatives are fully mixed, which contributes to the uniform structure and excellent final performance of the copolymer. At the same time, the outer layer of the functional group's hydrophobic group can block the infiltration of water vapor, and the inner layer contains nitrogen and oxygen coordination sites, which are conducive to the formation of reversible bonds with metal clusters and lithium salts, combining mechanical enhancement and ion channel provision, thereby improving the corrosion resistance of the electrode material.

[0067] Functional groups also include silane groups (such as methyltriethoxysilane), which can form a cross-linked network on the surface of the electrode material, helping to further enhance the structural stability of the electrode material, especially during long-term charging and discharging.

[0068] S2.3. Add an initiator to the mixed solution and carry out a polymerization reaction at a temperature of 60 - 80 °C for 4 - 6 h. Stir during the reaction process. After the reaction is completed, filter to remove unreacted monomers and impurities, and obtain a copolymer matrix after drying. The initiator includes at least one of sodium persulfate, hydrogen peroxide, and diphenyl peroxide.

[0069] By adding an initiator, the polymerization reaction is initiated to trigger the polymerization of monomers and form long-chain copolymers. The role of the initiator is to generate free radicals or ions to promote the polymerization reaction of monomers. The selection of the initiator can control the rate and degree of polymerization of the polymerization reaction.

[0070] Carrying out the polymerization reaction at a temperature of 60 - 80 °C can ensure that the reaction proceeds fully, while avoiding the occurrence of side reactions caused by too high a temperature. Temperature control ensures that the structure and properties of the copolymer are optimized. After 4 - 6 hours of polymerization reaction, functional organic groups combine with cellulose derivatives to form copolymers, enhancing the conductivity, mechanical strength, and stability of the final material.

[0071] By filtering to remove unreacted monomers, impurities, and solvents, a pure copolymer matrix is obtained, ensuring that it has high purity and performance. The dried copolymer matrix can remove solvents and moisture, enabling the final material to reach the required physical form and being suitable for subsequent battery assembly.

[0072] S3. Dissolve the coordination metal cluster and the copolymer matrix in a lithium salt solution and carry out a cross-linking reaction to obtain a composite solution.

[0073] Step S3 includes:

[0074] S3.1. First, dissolve the coordination metal cluster in a solvent and stir in a temperature-controlled stirrer to ensure the solution is uniform and the reaction temperature is controlled at 50 - 70 °C to obtain a coordination metal cluster solution. Among them, the solvent includes at least one of absolute ethanol, dimethyl sulfoximide, and N,N-dimethylformamide.

[0075] Dissolve the coordination metal cluster in an appropriate solvent to ensure that metal ions are fully dissolved and form a stable solution with the solvent. Dissolving the metal cluster is the basis for the smooth progress of subsequent reactions. Selecting solvents such as absolute ethanol, dimethyl sulfoximide (DMSO), and N,N-dimethylformamide (DMF) is to optimize the solubility and stability of the metal cluster. In particular, DMSO and DMF, as polar solvents, help improve the solubility of metal salts and will not have an adverse effect on the coordination reaction.

[0076] Stir in a temperature-controlled stirrer and maintain the reaction temperature within the range of 50 - 70 °C, which helps to accelerate the dissolution process of metal clusters and ensure the uniform distribution of metal ions in the solution. Excessive temperature may cause the volatilization of certain solvents or the degradation of metal clusters, while too low temperature may lead to incomplete dissolution. Therefore, appropriate temperature control is crucial for the reaction efficiency. By using a temperature-controlled stirrer, the uniformity of the metal cluster solution can be ensured, enabling the uniform distribution of metal ions, avoiding precipitation or incomplete dissolution, and ensuring the smooth progress of subsequent cross-linking reactions.

[0077] S3.2. Dissolve the copolymer matrix in anhydrous ethanol or acetone, use a heating stirrer, and maintain the temperature between 50 - 60 °C to obtain a copolymer solution. Then add the coordinated metal cluster solution to the copolymer solution and stir for 1 - 2 h to obtain a composite solution.

[0078] Dissolve the copolymer matrix in anhydrous ethanol or acetone to ensure that the copolymer can be fully dissolved and form a uniform solution. The choice of solvent can improve the solubility and reactivity of the copolymer, avoid group aggregation, and ensure a uniform reaction. Use a heating stirrer to stir the copolymer solution and maintain the temperature between 50 - 60 °C, which helps to accelerate the dissolution process of the copolymer, avoid excessive evaporation of the solution at high temperature, and promote the uniform dissolution and dispersion of the copolymer. Controlling the temperature within this range can ensure the smooth progress of the dissolution process without damaging the polymer structure.

[0079] Add the coordinated metal cluster solution to the already dissolved copolymer solution and ensure thorough mixing of the metal clusters and the copolymer matrix by stirring. This step is to ensure the interaction between the metal clusters and the copolymer, thereby enhancing the structural stability and electrochemical performance of the composite material. Stirring for 1 - 2 hours helps to ensure the uniform distribution of the coordinated metal clusters in the copolymer matrix, forming a good composite solution. Through this process, the interaction between the coordinated metal clusters and the copolymer matrix can be fully exerted.

[0080] S4. Add the electrode active material to the composite solution, stir evenly to remove bubbles, then coat it on the current collector and dry to obtain the electrode material for a lithium-ion solid-state battery.

[0081] In step S4, the electrode active material includes a positive electrode active material or a negative electrode active material. The positive electrode active material includes at least one of lithium cobalt oxide, lithium iron phosphate, and nickel-rich ternary materials. The negative electrode active material includes at least one of graphite, silicon-based materials, and lithium metal. The current collector includes a positive electrode current collector or a negative electrode current collector. The positive electrode current collector includes at least one of aluminum foil, nickel foil, and titanium foil. The negative electrode current collector includes at least one of copper foil, stainless steel foil, and nickel foil.

[0082] The mass ratio of the electrode active material to the composite solution is usually controlled at 70~90:10~30 and adjusted according to specific application requirements. The positive electrode active material is usually used for the positive electrode of the battery. These materials have a high specific capacity, good electrochemical stability, and a long cycle life. The negative electrode active material is used for the negative electrode of the battery and has good conductivity and a high cycle efficiency.

[0083] S4.1: Add the selected electrode active material to the composite solution and stir it using a magnetic stirrer. Set the stirring speed to 500~1000 rpm to ensure that the active material and the composite solution are fully mixed.

[0084] S4.2: Use a vacuum degassing machine or an ultrasonic degassing device for degassing. Set the vacuum pressure to 20~50 kPa and perform degassing at room temperature for 10~20 min. After degassing is completed, coat it on the current collector.

[0085] Coating method: Coating can be carried out by common methods such as doctor blade coating, casting method, or spin coating method. Usually, the coating method is selected according to the viscosity of the solution and the requirements of the electrode film. Doctor blade coating: Suitable for thick film coating and commonly used in the preparation of battery electrode materials. Use a flat knife to evenly coat the composite solution on the surface of the current collector. Casting method: Use a casting device to evenly coat the solution on the surface of the current collector, suitable for large-area coating. Spin coating method: Suitable for coating of thinner film layers, especially for high-performance batteries and commonly used in the preparation of thin film batteries. Equipment: Commonly used equipment includes coating machines, casting machines, and spin coaters. The coating speed and thickness can be adjusted according to needs. The thickness of the coated film is usually between 50~100 μm. Control the coating speed and coating thickness to ensure that the coating is uniform and avoid cracks or bubbles.

[0086] Among them, the slurry added with the positive electrode active material is correspondingly coated on the positive electrode current collector, and the slurry added with the negative electrode active material is correspondingly coated on the negative electrode current collector.

[0087] S4.3: Use a constant temperature oven or a vacuum drying oven for drying. Set the temperature to 50~80 °C and the drying time to 4~8 h. After drying is completed, raise the temperature to 100~150 °C and keep it warm for 2~4 h to obtain the lithium-ion solid-state battery electrode material. Drying is to remove the solvent, form a solid film of the electrode material, and improve its structural stability. After drying is completed, perform heat treatment on the coated electrode material to improve the structural stability of the electrode material and remove residual solvent or moisture.

[0088] In the present invention, a scanning electron microscope (SEM) and a transmission electron microscope (TEM) can also be used to characterize the coated electrode material, observe the microstructure of the electrode surface and interior, and ensure the uniformity and defect control of the material. Electrochemical impedance spectroscopy (EIS) tests are carried out to verify the ionic conductivity and electrochemical performance of the electrode material. The prepared electrode material is assembled with the negative electrode material and the solid electrolyte to form a lithium-ion solid-state battery. Its performance is evaluated through charge-discharge tests, including specific capacity, cycle life, rate performance, etc.

[0089] The present invention provides an electrode material for a lithium-ion solid-state battery, which is prepared by a preparation method of an electrode material for a lithium-ion solid-state battery. The electrode material for a lithium-ion solid-state battery includes a coordination metal cluster, a copolymer matrix, and a lithium salt; wherein,

[0090] The coordination metal cluster is used to enhance the conductivity, stability, and interaction with lithium ions of the electrode material for a lithium-ion solid-state battery;

[0091] The copolymer matrix is used to provide structural support, enhance mechanical strength, and assist in lithium ion transport;

[0092] The lithium salt is used to provide a lithium ion source and promote ionic conductivity.

[0093] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing an electrode of a lithium-ion solid-state battery, characterized in that the steps Comprising: S1. Add a nitrogen source and a carboxyl auxiliary ligand to a metal salt solution, and carry out a thermal synthesis reaction to obtain a coordination metal cluster; In the step S1, the nitrogen source includes at least one of imidazoline, pyridine, and ethylenediamine, the carboxyl auxiliary ligand includes at least one of p-carboxylic acid, oxalic acid, and acetic acid, and the metal salt solution includes at least one of a copper nitrate salt solution, a zinc nitrate salt solution, and a cobalt chloride salt solution. Calculated by mass ratio, the nitrogen source: the carboxyl auxiliary ligand: the metal salt solution = 1-3:1:1; S2. Mix a cellulose derivative and a functional organic group, and then add a dispersant and an initiator to carry out a polymerization reaction to obtain a copolymer matrix; In step S2, the cellulose derivative includes at least one of cellulose ether, cellulose acetate, and cellulose ester, the functional organic group includes at least one of an acrylate group and an imidazoline group, the initiator includes at least one of sodium persulfate, hydrogen peroxide, and diphenyl peroxide, and the dispersant includes at least one of polyvinylpyrrolidone, sodium dodecylbenzenesulfonate, and polyvinyl alcohol; Calculated by mass ratio, the functional organic group: the cellulose derivative = 1:4-10; S3. Dissolve the coordination metal cluster and the copolymer matrix in a lithium salt solution, and carry out a cross-linking reaction to obtain a composite solution; S4. Add an electrode active material to the composite solution, stir evenly and then defoam to obtain a slurry of a lithium ion solid state battery electrode material, and then coat the slurry of the lithium ion solid state battery electrode material on a current collector and dry to obtain a lithium ion solid state battery electrode.

2. The preparation method of a lithium-ion solid-state battery electrode according to claim 1, wherein, The step S1 includes: S1.

1. Dissolve the selected metal salt in absolute ethanol or water, and stir until completely dissolved to obtain a metal salt solution; S1.

2. Add a nitrogen source and a carboxyl auxiliary ligand to the metal salt solution, heat up to 50-60 °C, and stir until completely dissolved; S1.

3. Heat up to 70-80 °C, keep warm for 2-6 h, naturally cool after the heat preservation is over, and then filter and dry to obtain a coordination metal cluster.

3. The preparation method of a lithium-ion solid-state battery electrode according to claim 1, characterized in that, The step S2 includes: S2.

1. Dissolve the cellulose derivative in water or absolute ethanol, and stir with a magnetic stirrer at room temperature to ensure that the cellulose derivative is completely dissolved to obtain a cellulose derivative solution; S2.

2. Add the functional organic group solution to the cellulose solution, add a dispersant while stirring, and stir for 20-30 min to obtain a mixed solution; S2.

3. Add an initiator to the mixed solution, carry out a polymerization reaction at a temperature of 60-80 °C, the reaction time is 4-6 h, keep stirring during the reaction, after the reaction is completed, filter to remove unreacted monomers and impurities, and dry to obtain a copolymer matrix.

4. The preparation method of a lithium-ion solid-state battery electrode according to claim 1, characterized in that, The step S3 includes: S3.

1. First dissolve the coordination metal cluster in a solvent, stir in a temperature-controlled stirrer to ensure that the solution is uniform, and control the reaction temperature at 50-70 °C to obtain a coordination metal cluster solution, wherein the solvent includes at least one of absolute ethanol, dimethyl sulfoxide amide, and N,N-dimethylformamide; S3.

2. Dissolve the copolymer matrix in anhydrous ethanol or acetone, and use a heating stirrer to maintain the temperature between 50 and 60 °C to obtain a copolymer solution. Then add the coordination metal cluster solution to the copolymer solution and stir for 1 to 2 h to obtain a composite solution.

5. The preparation method of a lithium-ion solid-state battery electrode according to claim 1, wherein, In the step S4, the electrode active material includes a positive electrode active material or a negative electrode active material. The positive electrode active material includes at least one of lithium cobaltate, lithium iron phosphate, and nickel-rich ternary materials. The negative electrode active material includes at least one of graphite, silicon-based materials, and lithium metal. The current collector includes a positive electrode current collector or a negative electrode current collector. The positive electrode current collector includes at least one of aluminum foil, nickel foil, and titanium foil. The negative electrode current collector includes at least one of copper foil, stainless steel foil, and nickel foil.

6. A lithium-ion solid-state battery electrode, characterized in that, Manufactured by the preparation method of a lithium-ion solid-state battery electrode according to any one of claims 1 to 5, the lithium-ion solid-state battery electrode includes a lithium-ion solid-state battery electrode material, and the lithium-ion solid-state battery electrode material includes a coordination metal cluster, a copolymer matrix, and a lithium salt; wherein, The coordination metal cluster is used to enhance the conductivity, stability of the lithium-ion solid-state battery electrode material, and the interaction with lithium ions; The copolymer matrix is used to provide structural support, enhance mechanical strength, and assist in lithium ion transport; The lithium salt is used to provide a lithium ion source and promote ionic conductivity.

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