Polymer and NASICON ceramic high-performance composite solid electrolyte based on photocuring technology and preparation method of polymer and NASICON ceramic high-performance composite solid electrolyte

Abstract

The invention relates to the technical field of solid electrolytes, in particular to a high-performance composite solid electrolyte of a polymer and NASICON ceramic based on a photocuring technology and a preparation method of the high-performance composite solid electrolyte. The problem that the mechanical property and the conductivity of the solid electrolyte formed by the common technology cannot be simultaneously realized is solved. The Naokuai composite solid electrolyte is composed of an acrylate polymer matrix, a ceramic filler, a lithium salt and a photoinitiator. By optimizing the formula design of the polyethylene glycol polymer matrix and the ceramic filler and the photocuring preparation process, the ionic conductivity, the mechanical property and the electrochemical stability of the solid electrolyte are remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of solid electrolytes, and in particular to a high-performance composite solid electrolyte of a polymer and NASICON ceramics based on photocuring technology and a preparation method thereof. Background Art

[0002] As energy demand continues to grow, lithium-ion batteries have become an important battery technology widely used in consumer electronics, electric vehicles and stationary energy storage systems. However, traditional lithium-ion batteries use organic liquid electrolytes, which have high flammability, low thermal stability and flash point. If used improperly, they are prone to fire or explosion, posing serious safety hazards.

[0003] Solid-state lithium batteries do not use liquid electrolytes, but solid electrolytes, which have higher energy density and higher electrochemical stability, and are compatible with high-voltage positive electrode materials, thereby further improving the energy density of the battery. In addition, solid-state electrolytes also have excellent mechanical properties, which can improve the safety and service life of the battery. Existing solid-state lithium batteries can generally be divided into two categories: one is a polymer-based solid-state lithium battery, and the other is a solid-state lithium battery based on inorganic materials (such as ceramics). Ceramic solid electrolytes have high Li+ ion conductivity and thermal stability, but they are very brittle and it is difficult to achieve good interface contact with electrode materials; polymer electrolytes have good processability and flexibility, but poor ionic conductivity at room temperature, which limits their application in high-performance batteries.

[0004] Therefore, it is urgent to propose a high-performance composite solid electrolyte of polymer and NASICON ceramic based on photocuring technology and a preparation method to solve the above technical problems. Summary of the invention

[0005] The present invention is to solve the problem that the mechanical properties and conductivity of the solid electrolyte formed by the conventional technology cannot be combined. A brief summary of the present invention is given below to provide a basic understanding of certain aspects of the present invention. It should be understood that this summary is not an exhaustive summary of the present invention. It is not intended to determine the key or important parts of the present invention, nor is it intended to limit the scope of the present invention.

[0006] The technical solution of the present invention:

[0007] A high-performance composite solid electrolyte of a polymer based on photocuring technology and NASICON ceramics, wherein the high-performance composite solid electrolyte of a polymer based on photocuring technology and NASICON ceramics is composed of an acrylic polymer matrix, a ceramic filler, a lithium salt, and a photoinitiator;

[0008] The mass fraction of the acrylic polymer matrix is ​​0.551-0.992 parts, the mass fraction of the ceramic filler is 0-0.5 parts, the mass fraction of the lithium salt is 0.448-0.808 parts, and the mass fraction of the photoinitiator is 0.005-0.009 parts.

[0009] Preferably, the acrylic polymer matrix is ​​one of polyethylene glycol dimethacrylate and polyethylene glycol dimethacrylate or a cross-linked product thereof.

[0010] Preferably, the ceramic filler is one or more of NASICON type Li1+xAlxGe2-x(PO4)3 and Li1+xAlxTi2-x(PO4)3.

[0011] Preferred: The lithium salt is lithium bis(trifluoromethanesulfonyl)imide.

[0012] Preferred: The photoinitiator is dimethyl methylphosphonate.

[0013] A method for preparing a high-performance composite solid electrolyte of a polymer and NASICON ceramic based on photocuring technology comprises the following steps:

[0014] Step 1: Mix polyethylene glycol dimethacrylate, polyethylene glycol methyl methacrylate and ceramic filler, add lithium salt, and adjust the molar ratio of ether oxygen to lithium ion to 8, add photoinitiator, and stir evenly to form slurry;

[0015] Step 2: Casting the slurry into a polytetrafluoroethylene mold through a vacuum packaging machine to form a film;

[0016] Step 3: placing the film under an ultraviolet light source for irradiation to complete curing and prepare a self-supporting composite polymer solid electrolyte film;

[0017] Step 4: Post-process the cured film to ensure uniform film size and avoid residual solvent affecting its performance.

[0018] Preferably, the stirring temperature in step 1 is 40° C. and the stirring time is 30 min.

[0019] Preferably, the film has a thickness of 100-150 μm.

[0020] Preferably: the intensity of the UV light source is 125 mW / cm 2 , the irradiation time is 10min.

[0021] The present invention has the following beneficial effects:

[0022] The present invention significantly improves the ionic conductivity, mechanical properties and electrochemical stability of the solid electrolyte by optimizing the formula design of the polyethylene glycol polymer matrix and the ceramic filler and the photocuring preparation process;

[0023] The present invention significantly improves the ionic conductivity, mechanical properties and electrochemical stability of the composite polymer solid electrolyte, provides an effective solution for the application of high-performance lithium metal batteries, and promotes the further development of solid-state battery technology. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is described below by specific embodiments. However, it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0025] Specific implementation method 1: In this implementation method, a high-performance composite solid electrolyte of a polymer based on photocuring technology and NASICON ceramics is provided. The high-performance composite solid electrolyte of a polymer based on photocuring technology and NASICON ceramics is composed of an acrylic polymer matrix, a ceramic filler, a lithium salt, and a photoinitiator;

[0026] The mass fraction of the acrylic polymer matrix is ​​0.551-0.992 parts, the mass fraction of the ceramic filler is 0-0.5 parts, the mass fraction of the lithium salt is 0.448-0.808 parts, and the mass fraction of the photoinitiator is 0.005-0.009 parts.

[0027] By mixing the above materials, the polymer matrix is ​​cured under ultraviolet light using photocuring technology, and the ceramic filler and lithium salt are evenly distributed to form a high-performance composite solid electrolyte. The characteristics of this composite electrolyte include high ionic conductivity, good mechanical properties, and adaptability to the needs of high-efficiency battery systems.

[0028] Specific embodiment 2: This embodiment is a high-performance composite solid electrolyte of a polymer based on photocuring technology and NASICON ceramics. The acrylate polymer matrix is ​​one of polyethylene glycol dimethacrylate and polyethylene glycol dimethacrylate or a cross-linked product. The overall performance of the composite material is improved, and it has good conductivity, mechanical strength and environmental stability, and is suitable for high-efficiency solid-state battery systems.

[0029] Specific implementation method three: This implementation method is a high-performance composite solid electrolyte of a polymer and NASICON ceramic based on photocuring technology, and the ceramic filler is one or more of NASICON-type Li1+xAlxGe2-x(PO4)3 and Li1+xAlxTi2-x(PO4)3. This filler can not only significantly improve the ionic conductivity and mechanical properties of the composite solid electrolyte, but also enhance the stability of the material under harsh conditions such as high temperature and high pressure, thereby further optimizing the overall performance of the solid-state battery.

[0030] Specific implementation method 4: This implementation method is a high-performance composite solid electrolyte of a polymer and NASICON ceramic based on photocuring technology, and the lithium salt is lithium bis(trifluoromethanesulfonyl)imide.

[0031] Lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) as a lithium salt plays a key role in the high-performance composite solid electrolyte based on photocuring technology polymer and NASICON ceramic. It can not only improve the ionic conductivity of the electrolyte, but also enhance the chemical stability, thermal stability and mechanical strength of the electrolyte, thereby improving the performance of the entire composite electrolyte and meeting the needs of high-performance battery systems.

[0032] Specific implementation method 5: This implementation method is a high-performance composite solid electrolyte of a polymer and NASICON ceramic based on photocuring technology, and the photoinitiator is dimethyl methyl phosphonate.

[0033] As a photoinitiator, dimethyl methylphosphonate (DMMP) plays an important role in the composite solid electrolyte of polymer and NASICON ceramic based on photocuring technology. It initiates polymerization reaction, so that the polymer matrix forms a highly cross-linked network structure, thereby improving the mechanical strength, ionic conductivity and stability of the solid electrolyte. At the same time, its good compatibility with NASICON ceramics makes the composite material have great potential for application in high-performance lithium batteries.

[0034] Specific implementation method 6: A method for preparing a high-performance composite solid electrolyte of a polymer and NASICON ceramic based on photocuring technology in this implementation method comprises the following steps:

[0035] Step 1: Mix polyethylene glycol dimethacrylate, polyethylene glycol methyl methacrylate and ceramic filler, add lithium salt, and adjust the molar ratio of ether oxygen to lithium ion to 8, add photoinitiator, and stir evenly to form slurry;

[0036] Step 2: Casting the slurry into a polytetrafluoroethylene mold through a vacuum packaging machine to form a film;

[0037] Step 3: placing the film under an ultraviolet light source for irradiation to complete curing and prepare a self-supporting composite polymer solid electrolyte film;

[0038] Step 4: Post-process the cured film to ensure uniform film size and avoid residual solvent affecting its performance.

[0039] This preparation method successfully prepared a high-performance composite solid electrolyte film by combining polymer and NASICON ceramic filler through photocuring technology. This method not only has high production efficiency, but also can accurately control the structure and performance of the film, which is suitable for application fields such as solid-state batteries.

[0040] Specific implementation method seven: In this implementation method, a high-performance composite solid electrolyte of a polymer and NASICON ceramic based on photocuring technology is prepared. In step 1, the stirring temperature is 40°C and the stirring time is 30 minutes, which helps to improve the dispersion, uniformity and reaction efficiency of the composite material, thereby optimizing the overall performance of the composite solid electrolyte. This optimization of temperature and time enables the material to achieve optimal ionic conductivity and mechanical strength during the preparation process, and is suitable for the application of high-performance solid electrolytes.

[0041] Specific implementation eight: This implementation method is a method for preparing a high-performance composite solid electrolyte of a polymer and NASICON ceramic based on photocuring technology, wherein the film thickness is 100-150 μm, which helps to optimize ionic conductivity, mechanical strength, thermal stability and interface contact while ensuring that the performance of the solid electrolyte film meets the requirements of high-performance batteries. This thickness can provide the composite solid electrolyte with the best physical and electrochemical properties, and is suitable for the application of different types of batteries.

[0042] Specific embodiment 9: A method for preparing a high-performance composite solid electrolyte of a polymer and NASICON ceramic based on photocuring technology in this embodiment, the intensity of the ultraviolet light source is 125mW / cm 2 , the irradiation time is 10min.

[0043] 125mW / cm 2 The light intensity of 125mW / cm and the irradiation time of 10 minutes help improve the long-term stability of the composite solid electrolyte. Moderate light intensity can effectively cure the material and reduce the presence of uncured areas, thereby reducing the risk of aging or performance degradation of the material during use. Especially for solid electrolytes used in batteries, better stability means a longer service life. In the production process, the light intensity and curing time of light curing directly affect the production efficiency. 2The light intensity of 10 and the curing time of 10 minutes can ensure high production efficiency and reduce unnecessary time consumption while ensuring material performance. By optimizing these two parameters, the production speed of solid electrolyte membrane can be increased, thereby reducing costs and meeting the needs of large-scale production.

[0044] Example 1

[0045] A method for preparing a high-performance composite solid electrolyte of a polymer and NASICON ceramic based on photocuring technology comprises the following steps:

[0046] Step 1: Weigh 0.165 g of polyethylene glycol dimethacrylate, 0.386 g of polyethylene glycol methacrylate, 0.449 g of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), and 0.005 g of dimethyl methylphosphonate (DMPP), add all the components into a mixing container, and stir at 40° C. for 30 minutes at a stirring speed of 300 r / min until a uniform slurry is formed;

[0047] Step 2: Use a vacuum packaging machine to cast the uniform slurry into a polytetrafluoroethylene mold, and control the film thickness to be 120 μm;

[0048] Step 3: Place the mold under a strength of 125mW / cm 2 The film was irradiated under a UV light source for 10 minutes to complete the curing and obtain a solid polymer film;

[0049] Step 4: Post-processing of the cured film, including trimming and drying, to ensure uniform film size and avoid residual solvent affecting its performance.

[0050] Example 2

[0051] A method for preparing a high-performance composite solid electrolyte of a polymer and NASICON ceramic based on photocuring technology comprises the following steps:

[0052] Step 1: Weigh 0.275 g of polyethylene glycol dimethacrylate, 0.276 g of polyethylene glycol methacrylate, 0.449 g of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), and 0.005 g of dimethyl methylphosphonate (DMPP), and add all the components into a mixing container; stir at 40° C. for 30 minutes at a stirring speed of 300 r / min until a uniform slurry is formed;

[0053] Step 2: Use a vacuum packaging machine to cast the uniform slurry into a polytetrafluoroethylene mold, and control the film thickness to be 120 μm;

[0054] Step 3: Place the mold under a strength of 125mW / cm 2The film was irradiated under a UV light source for 10 minutes to complete the curing and obtain a solid polymer film;

[0055] Step 4: Post-processing of the cured film, including trimming and drying, to ensure uniform film size and avoid residual solvent affecting its performance.

[0056] Example 3

[0057] A method for preparing a high-performance composite solid electrolyte of a polymer and NASICON ceramic based on photocuring technology comprises the following steps:

[0058] Step 1: Weigh 0.386 g of polyethylene glycol dimethacrylate, 0.165 g of polyethylene glycol methacrylate, 0.449 g of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), and 0.005 g of dimethyl methylphosphonate (DMPP), add all the components into a mixing container, and stir at 40° C. for 30 minutes at a stirring speed of 300 r / min until a uniform slurry is formed;

[0059] Step 2: Use a vacuum packaging machine to cast the uniform slurry into a polytetrafluoroethylene mold, and control the film thickness to be 120 μm;

[0060] Step 3: Place the mold under a strength of 125mW / cm 2 The film was irradiated under a UV light source for 10 minutes to complete the curing and obtain a solid polymer film;

[0061] Step 4: Post-processing of the cured film, including trimming and drying, to ensure uniform film size and avoid residual solvent affecting its performance.

[0062] Example 4

[0063] A method for preparing a high-performance composite solid electrolyte of a polymer and NASICON ceramic based on photocuring technology comprises the following steps:

[0064] Step 1: Weigh 0.298 g of polyethylene glycol dimethacrylate, 0.694 g of polyethylene glycol methacrylate, 0.808 g of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), 0.2 g of Li1+xAlxGe2-x(PO4)3(LAGP), and 0.009 g of dimethyl methylphosphonate (DMPP), add all the components into a mixing container, and stir at 40°C for 30 minutes at a stirring speed of 300 r / min until a uniform slurry is formed;

[0065] Step 2: Use a vacuum packaging machine to cast the uniform slurry into a polytetrafluoroethylene mold, and control the film thickness to be 120 μm;

[0066] Step 3: Place the mold under a strength of 125mW / cm 2 The film was irradiated under a UV light source for 10 minutes to complete the curing and obtain a solid polymer film;

[0067] Step 4: Post-processing of the cured film, including trimming and drying, to ensure uniform film size and avoid residual solvent affecting its performance.

[0068] Example 5

[0069] A method for preparing a high-performance composite solid electrolyte of a polymer and NASICON ceramic based on photocuring technology comprises the following steps:

[0070] Step 1: Weigh 0.248 g of polyethylene glycol dimethacrylate, 0.578 g of polyethylene glycol methacrylate, 0.674 g of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), 0.5 g of Li1+xAlxGe2-x(PO4)3(LAGP), and 0.008 g of dimethyl methylphosphonate (DMPP), and add all the components into a mixing container; stir at 40°C for 30 minutes at a stirring speed of 300 r / min until a uniform slurry is formed;

[0071] Step 2: Use a vacuum packaging machine to cast the uniform slurry into a polytetrafluoroethylene mold, and control the film thickness to be 120 μm;

[0072] Step 3: Place the mold under a strength of 125mW / cm 2 The film was irradiated under a UV light source for 10 minutes to complete the curing and obtain a solid polymer film;

[0073] Step 4: Post-processing of the cured film, including trimming and drying, to ensure uniform film size and avoid residual solvent affecting its performance.

[0074] Example 6

[0075] A method for preparing a high-performance composite solid electrolyte of a polymer and NASICON ceramic based on photocuring technology comprises the following steps:

[0076] Step 1: Weigh 0.165 g of polyethylene glycol dimethacrylate, 0.386 g of polyethylene glycol methacrylate, 0.449 g of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), 1 g of Li1+xAlxGe2-x(PO4)3(LAGP), and 0.005 g of dimethyl methylphosphonate (DMPP); add all the components into a mixing container, stir at 40°C for 30 minutes at a stirring speed of 300 r / min until a uniform slurry is formed;

[0077] Step 2: Use a vacuum packaging machine to cast the uniform slurry into a polytetrafluoroethylene mold, and control the film thickness to be 120 μm;

[0078] Step 3: Place the mold under a strength of 125mW / cm 2 The film was irradiated under a UV light source for 10 minutes to complete the curing and obtain a solid polymer film;

[0079] Step 4: Post-processing of the cured film, including trimming and drying, to ensure uniform film size and avoid residual solvent affecting its performance.

[0080] The performance of the composite polymer solid electrolyte films prepared in Examples 1 to 6 was tested, and the results are shown in the following table:

[0081]

[0082] 1. Electrochemical Impedance Spectroscopy

[0083] Using electrochemical impedance spectroscopy (EIS) determination, the sample was sandwiched between stainless steel electrodes, and the test frequency range was 100kHz to 1Hz. The ionic conductivity of Example 1 and Example 6 reached 1.47×10-4, which is significantly higher than that of other samples. This is attributed to the high segment flexibility provided by polyethylene glycol dimethacrylate and the strong polar lithium salt dissociation effect of vinyl carbonate (VC) side chain. In addition, the optimized TFEA content further improves the ion migration capacity.

[0084] 2. Mechanical properties test

[0085] The mechanical elongation of the sample was measured on a tensile tester. The mechanical elongation of Example 5 and Example 6 was 2600% and 2700%, respectively, which was significantly better than that of other examples and comparative samples. This is because the synergistic effect of TFEA and polyethylene glycol methacrylate MA optimized the flexibility of the film, while VC provided mechanical support, thereby achieving strength, toughness and balance.

[0086] As can be seen from the above results, Example 1 and Example 4 show a good balance in ionic conductivity and mechanical properties, indicating that by reasonably controlling the amount of LAGP added, it is possible to maintain excellent mechanical properties while improving the ion migration ability. Although the addition of LAGP helps to improve the conductivity of the electrolyte, excessive LAGP will lead to the formation of cracks, thereby significantly reducing the mechanical elongation and affecting the smooth conduction of lithium ions. Therefore, the appropriate addition of LAGP is crucial to the comprehensive performance of the composite polymer solid electrolyte. Optimizing the formula and strictly controlling the amount of LAGP added not only helps to improve the ionic conductivity of the electrolyte, but also ensures the mechanical stability of the film, thereby achieving good ion migration ability and excellent electrochemical stability. In general, the composite polymer solid electrolyte film prepared in this study shows excellent comprehensive performance in ionic conductivity, mechanical properties and electrochemical stability. In particular, in Example 1 and Example 4, by optimizing the amount of LAGP added, the ion migration ability and mechanical properties are successfully balanced, achieving the best overall effect. This provides solid technical support for the research and development of high-performance solid-state lithium metal batteries and shows broad application prospects.

[0087] It should be noted that in the above embodiments, as long as the technical solutions are not contradictory, they can be arranged and combined, and those skilled in the art can exhaust all possibilities based on the mathematical knowledge of arrangement and combination. Therefore, the present invention will no longer describe the technical solutions after arrangement and combination one by one, but it should be understood that the technical solutions after arrangement and combination have been disclosed by the present invention.

[0088] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A high-performance composite solid electrolyte of a polymer and NASICON ceramic based on photocuring technology, characterized in that: The high-performance composite solid electrolyte of the polymer and NASICON ceramic based on the photocuring technology is composed of an acrylic polymer matrix, a ceramic filler, a lithium salt, and a photoinitiator; The mass fraction of the acrylic polymer matrix is ​​0.551-0.992 parts, the mass fraction of the ceramic filler is 0-0.5 parts, the mass fraction of the lithium salt is 0.448-0.808 parts, and the mass fraction of the photoinitiator is 0.005-0.009 parts.

2. The high-performance composite solid electrolyte of a polymer and NASICON ceramic based on photocuring technology according to claim 1, characterized in that: The acrylic polymer matrix is ​​one of methoxy polyethylene glycol methacrylate and polyethylene glycol dimethacrylate or a cross-linked product.

3. The high-performance composite solid electrolyte of a polymer and NASICON ceramic based on photocuring technology according to claim 1, characterized in that: The ceramic filler is one or more of NASICON type Li1+xAlxGe2-x(PO4)3 and Li1+xAlxTi2-x(PO4)3.

4. The high-performance composite solid electrolyte of a polymer and NASICON ceramic based on photocuring technology according to claim 1, characterized in that: The lithium salt was lithium bis(trifluoromethanesulfonyl)imide.

5. The high-performance composite solid electrolyte of a polymer and NASICON ceramic based on photocuring technology according to claim 1, characterized in that: The photoinitiator was dimethyl methylphosphonate.

6. A method for preparing a high-performance composite solid electrolyte of a polymer and NASICON ceramic based on photocuring technology, characterized in that: The steps include: Step 1: Mix polyethylene glycol dimethacrylate, polyethylene glycol methyl methacrylate and ceramic filler, add lithium salt, and adjust the molar ratio of ether oxygen to lithium ion to 8, add photoinitiator, and stir evenly to form slurry; Step 2: Casting the slurry into a polytetrafluoroethylene mold through a vacuum packaging machine to form a film; Step 3: placing the film under an ultraviolet light source for irradiation to complete curing and prepare a self-supporting composite polymer solid electrolyte film; Step 4: Post-process the cured film to ensure uniform film size and avoid residual solvent affecting its performance.

7. The method for preparing a high-performance composite solid electrolyte of a polymer and NASICON ceramic based on photocuring technology according to claim 6, characterized in that: In step 1, the stirring temperature is 40° C. and the stirring time is 30 min.

8. The method for preparing a high-performance composite solid electrolyte of a polymer and NASICON ceramic based on photocuring technology according to claim 6, characterized in that: The film thickness is 100-150 μm.

9. The method for preparing a high-performance composite solid electrolyte of a polymer and NASICON ceramic based on photocuring technology according to claim 6, characterized in that: The intensity of the UV light source is 125mW / cm 2 , the irradiation time is 10min.

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