Homopolymerization process method for in-situ polymerization of solid electrolyte

Abstract

The invention discloses a uniform polymerization process method for in-situ polymerization of a solid electrolyte, which specifically comprises the following steps: S1, raw material selection: selecting a monomer with a double bond or a fork chain structure, selecting a proper initiator according to the property of the selected monomer, and adding a proper amount of additive; the invention relates to the technical field of solid-state batteries. According to the uniform polymerization process method of the in-situ polymerization solid electrolyte, uniform polymerization of the in-situ polymerization solid electrolyte is realized by optimizing polymerization process conditions, such as stirring and dispersion, temperature gradient control and monomer concentration optimization, and the ionic conductivity and chemical stability of the electrolyte are improved; the uniform electrolyte structure is beneficial to rapid transmission of lithium ions, the internal impedance of the battery is reduced, the charge-discharge rate and the energy density of the battery are improved, and the in-situ polymerization solid electrolyte has excellent mechanical strength and chemical stability and can effectively inhibit internal short circuit of the battery and reduce the thermal runaway risk of the battery.

Description

Technical Field

[0001] This invention relates to the field of solid-state battery technology, specifically to a homogeneous polymerization process for in-situ polymerization of solid electrolytes. Background Technology

[0002] Solid-state batteries are batteries that use solid electrodes and solid electrolytes. The negative electrode material of a solid-state battery can be a composite negative electrode of nano-silicon and graphite, and the positive electrode can be lithium manganese oxide, lithium-rich manganese-based materials, or lithium-free positive electrode materials. The electrolyte is a solid electrolyte, with an energy density of 300-450 Wh / kg. Solid-state batteries use solid electrolytes to replace the electrolyte and separator of traditional lithium-ion batteries, making them safer, with higher energy density and stronger cycle performance. They have become the main research direction for next-generation power batteries. Solid electrolytes can be roughly divided into three categories: inorganic electrolytes, solid polymer electrolytes, and composite electrolytes. Due to the high power-to-weight ratio of solid-state batteries, they are ideal batteries for electric vehicles. With the rapid development of electric vehicles, portable electronic devices, and energy storage systems, the demand for high-performance batteries is increasing. Traditional liquid electrolytes have safety hazards such as leakage and flammability, which limit the further improvement of battery safety and energy density. As a new type of electrolyte, solid electrolytes have advantages such as high mechanical strength, good electrochemical stability, and good thermal stability, which can effectively solve the problems of liquid electrolytes and have become a hot topic in current battery technology research.

[0003] In-situ polymerized solid electrolytes are a technology in which the electrolyte is polymerized in situ on the electrode surface to form a solid electrolyte layer during battery operation. This technology can significantly improve the safety and performance of the battery, has rapid ion transport capabilities, and a conductivity of over 10^-6 S / cm, and remains stable over a wide temperature range. However, the current preparation process of in-situ polymerized solid electrolytes suffers from uneven polymerization, which leads to unstable electrolyte performance and affects the overall performance of the battery. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a homogeneous polymerization process for in-situ polymerizing solid electrolytes, which solves the problems mentioned in the background section.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a homogeneous polymerization process for in-situ polymerizing solid electrolytes, specifically comprising the following steps: S1. Raw material selection: Select monomers with double bond or cross-chain structure, select appropriate initiators and add appropriate additives according to the properties of the selected monomers. S2, Polymerization Process: (1) Pretreatment: Add polymer monomers, lithium salts, initiators and additives to the solvent in a certain proportion, and stir in a glove box filled with inert gas to prevent light from entering, so that the solids are fully dissolved and a uniform transparent liquid is obtained. The stirring time and temperature need to be optimized according to the properties of the raw materials to ensure that the components are fully mixed. (2) Coating: The pretreated slurry is coated onto the electrode surface or a specific mold. Coating methods can include blade coating, spin coating, etc., and the appropriate coating thickness and uniformity should be selected according to actual needs; (3) Polymerization reaction: Select appropriate polymerization reaction conditions according to the type of initiator. For photoinitiators, use ultraviolet light irradiation to carry out the polymerization reaction. Control the wavelength, power and irradiation time of the ultraviolet light to make the polymerization reaction proceed uniformly. Use a 120W ultraviolet lamp to irradiate at a wavelength of 365nm for 1.3h to carry out free radical polymerization reaction. (4) Post-processing: After the polymerization reaction is completed, the obtained solid electrolyte is post-processed; S3, Uniformity Control: (1) Stirring and dispersion: During the polymerization reaction, an appropriate stirring method is used to ensure that the monomer and initiator are evenly dispersed in the solution; (2) Temperature gradient control: During the polymerization reaction, the temperature gradient of the reaction system is controlled to avoid local temperatures being too high or too low. Heating jacket equipment is used to precisely control the temperature of the reaction system and ensure that the polymerization reaction proceeds under uniform temperature conditions. (3) Monomer concentration optimization: Optimize the monomer concentration to keep it within a suitable range. The optimal monomer concentration range is determined through experiments to ensure the uniformity of the polymerization reaction and the excellent performance of the electrolyte.

[0006] Preferably, in S1, the unit is one of 1,3-dioxolane, polyethylene oxide, or polyacrylonitrile; for free radical polymerization, azobisisobutyronitrile or benzoyl peroxide is selected; for cationic polymerization, lithium salt is selected as the initiator; and the additive includes one of functionalized polymers, functionalized fillers, or functionalized additives.

[0007] Preferably, in S1, the functionalized polymer is one of polyethylene oxide and polyethyleneimine, the functionalized filler is one of inorganic non-active ceramic filler or lithium-ion active filler, and the functionalized additive is one of interface stabilizer, film-forming additive, and anti-overcharge additive.

[0008] Preferably, in S2(1), the solvent is one of water, ethanol, or acetone, and the inert gas is argon.

[0009] Preferably, in step S2 (4), residual solvent is removed by methods such as vacuum drying to improve the purity and stability of the solid electrolyte.

[0010] Preferably, in step S3(1), the stirring method is either mechanical stirring or magnetic stirring. The stirring speed and time should be optimized according to the properties of the reaction system to ensure that the monomer and initiator are fully mixed and to avoid uneven polymerization caused by excessively high or low local concentrations.

[0011] Preferably, in S3 (3), if the monomer concentration is too high, the polymerization reaction may be too violent, resulting in gelation and affecting the uniformity of the electrolyte. If the monomer concentration is too low, the polymerization reaction may be incomplete, resulting in poor electrolyte performance. Beneficial effects

[0012] This invention provides a homogeneous polymerization process for in-situ polymerized solid electrolytes. Compared with existing technologies, it offers the following advantages: This homogeneous polymerization process for in-situ polymerized solid electrolytes achieves homogeneous polymerization of the solid electrolyte by optimizing polymerization conditions, such as stirring and dispersion, temperature gradient control, and monomer concentration optimization. This improves the ionic conductivity and chemical stability of the electrolyte. The homogeneous electrolyte structure facilitates rapid lithium-ion transport, reduces the battery's internal impedance, and increases the battery's charge / discharge rate and energy density. The in-situ polymerized solid electrolyte exhibits excellent mechanical strength and chemical stability, effectively suppressing internal short circuits and reducing the risk of thermal runaway. The homogeneous electrolyte structure further enhances battery safety, providing assurance for battery applications in various harsh environments. The homogeneously polymerized in-situ polymerized solid electrolyte has good interfacial compatibility with the electrodes, reducing interfacial impedance and improving the battery's cycle life and rate performance. Furthermore, the electrolyte's homogeneity helps improve battery consistency, reduces performance differences between individual cells in the battery pack, and improves the overall performance of the battery pack. Attached Figure Description

[0013] Figure 1 This is a flowchart of the steps of the present invention. Detailed Implementation

[0014] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0015] Please see Figure 1This invention provides a technical solution: a homogeneous polymerization process for in-situ polymerizing solid electrolytes, specifically including the following steps: S1. Raw material selection: Select monomers with double bond or cross-chain structure, select appropriate initiators and add appropriate additives according to the properties of the selected monomers. S2, Polymerization Process: (1) Pretreatment: Add polymer monomers, lithium salts, initiators and additives to the solvent in a certain proportion, and stir in a glove box filled with inert gas to prevent light from entering, so that the solids are fully dissolved and a uniform transparent liquid is obtained. The stirring time and temperature need to be optimized according to the properties of the raw materials to ensure that the components are fully mixed. (2) Coating: The pretreated slurry is coated onto the electrode surface or a specific mold. Coating methods can include blade coating, spin coating, etc., and the appropriate coating thickness and uniformity should be selected according to actual needs; (3) Polymerization reaction: Select appropriate polymerization reaction conditions according to the type of initiator. For photoinitiators, use ultraviolet light irradiation to carry out the polymerization reaction. Control the wavelength, power and irradiation time of the ultraviolet light to make the polymerization reaction proceed uniformly. Use a 120W ultraviolet lamp to irradiate at a wavelength of 365nm for 1.3h to carry out free radical polymerization reaction. (4) Post-processing: After the polymerization reaction is completed, the obtained solid electrolyte is post-processed; S3, Uniformity Control: (1) Stirring and dispersion: During the polymerization reaction, an appropriate stirring method is used to ensure that the monomer and initiator are evenly dispersed in the solution; (2) Temperature gradient control: During the polymerization reaction, the temperature gradient of the reaction system is controlled to avoid local temperatures being too high or too low. Heating jacket equipment is used to precisely control the temperature of the reaction system and ensure that the polymerization reaction proceeds under uniform temperature conditions. (3) Monomer concentration optimization: Optimize the monomer concentration to keep it within a suitable range. The optimal monomer concentration range is determined through experiments to ensure the uniformity of the polymerization reaction and the excellent performance of the electrolyte.

[0016] In this invention, in S1, the unit is one of 1,3-dioxolane, polyethylene oxide, and polyacrylonitrile. For free radical polymerization, azobisisobutyronitrile or benzoyl peroxide is selected. For cationic polymerization, lithium salt is selected as the initiator. The additive includes one of functionalized polymer, functionalized filler, and functionalized additive.

[0017] In this invention, in S1, the functionalized polymer is either polyethylene oxide or polyethyleneimine, the functionalized filler is either an inorganic non-active ceramic filler or a lithium-ion-conducting active filler, and the functionalized additive is either an interface stabilizer, a film-forming additive, or an anti-overcharge additive.

[0018] In this invention, in S2(1), the solvent is one of water, ethanol, or acetone, and the inert gas is argon.

[0019] In this invention, in step S2 (4), residual solvent is removed by methods such as vacuum drying to improve the purity and stability of the solid electrolyte.

[0020] In this invention, in S3(1), the stirring method is either mechanical stirring or magnetic stirring. The stirring speed and time should be optimized according to the properties of the reaction system to ensure that the monomer and initiator are fully mixed and to avoid uneven polymerization caused by excessively high or low local concentrations.

[0021] In this invention, in S3 (3), if the monomer concentration is too high, the polymerization reaction may be too violent, resulting in gelation and affecting the uniformity of the electrolyte. If the monomer concentration is too low, the polymerization reaction may be incomplete, resulting in poor electrolyte performance.

[0022] Furthermore, any content not described in detail in this specification is existing technology known to those skilled in the art.

[0023] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0024] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A homogeneous polymerization process for in-situ polymerization of solid electrolytes, characterized in that: Specifically, the following steps are included: S1. Raw material selection: Select monomers with double bond or cross-chain structure, select appropriate initiators and add appropriate additives according to the properties of the selected monomers. S2, Polymerization Process: (1) Pretreatment: Add polymer monomers, lithium salts, initiators and additives to the solvent in a certain proportion, and stir in a glove box filled with inert gas to prevent light from entering, so that the solids are fully dissolved and a uniform transparent liquid is obtained. The stirring time and temperature need to be optimized according to the properties of the raw materials to ensure that the components are fully mixed. (2) Coating: The pretreated slurry is coated onto the electrode surface or a specific mold. Coating methods can include blade coating, spin coating, etc., and the appropriate coating thickness and uniformity should be selected according to actual needs; (3) Polymerization reaction: Select appropriate polymerization reaction conditions according to the type of initiator. For photoinitiators, use ultraviolet light irradiation to carry out the polymerization reaction. Control the wavelength, power and irradiation time of the ultraviolet light to make the polymerization reaction proceed uniformly. Use a 120W ultraviolet lamp to irradiate at a wavelength of 365nm for 1.3h to carry out free radical polymerization reaction. (4) Post-processing: After the polymerization reaction is completed, the obtained solid electrolyte is post-processed; S3, Uniformity Control: (1) Stirring and dispersion: During the polymerization reaction, an appropriate stirring method is used to ensure that the monomer and initiator are evenly dispersed in the solution; (2) Temperature gradient control: During the polymerization reaction, the temperature gradient of the reaction system is controlled to avoid local temperatures being too high or too low. Heating jacket equipment is used to precisely control the temperature of the reaction system and ensure that the polymerization reaction proceeds under uniform temperature conditions. (3) Monomer concentration optimization: Optimize the monomer concentration to keep it within a suitable range. The optimal monomer concentration range is determined through experiments to ensure the uniformity of the polymerization reaction and the excellent performance of the electrolyte.

2. The homogeneous polymerization process for in-situ polymerized solid electrolytes according to claim 1, characterized in that: In S1, the unit is one of 1,3-dioxolane, polyethylene oxide, and polyacrylonitrile. For free radical polymerization, azobisisobutyronitrile or benzoyl peroxide is selected. For cationic polymerization, lithium salt is selected as the initiator. The additive includes one of functionalized polymer, functionalized filler, and functionalized additive.

3. The homogeneous polymerization process for in-situ polymerized solid electrolytes according to claim 1, characterized in that: In S1, the functionalized polymer is either polyethylene oxide or polyethyleneimine, the functionalized filler is either an inorganic non-active ceramic filler or a lithium-ion-conducting active filler, and the functionalized additive is either an interface stabilizer, a film-forming additive, or an anti-overcharge additive.

4. The homogeneous polymerization process for in-situ polymerized solid electrolytes according to claim 1, characterized in that: In S2(1), the solvent is one of water, ethanol, or acetone, and the inert gas is argon.

5. The homogeneous polymerization process for in-situ polymerized solid electrolytes according to claim 1, characterized in that: In step S2(4), residual solvent is removed by methods such as vacuum drying to improve the purity and stability of the solid electrolyte.

6. The homogeneous polymerization process for in-situ polymerized solid electrolytes according to claim 1, characterized in that: In S3(1), the stirring method is either mechanical stirring or magnetic stirring. The stirring speed and time should be optimized according to the properties of the reaction system to ensure that the monomer and initiator are fully mixed and to avoid uneven polymerization caused by excessively high or low local concentrations.

7. The homogeneous polymerization process for in-situ polymerized solid electrolytes according to claim 1, characterized in that: In S3(3), if the monomer concentration is too high, the polymerization reaction may be too violent, resulting in gelation and affecting the uniformity of the electrolyte. If the monomer concentration is too low, the polymerization reaction may be incomplete, resulting in poor electrolyte performance.

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