Polymer solid electrolyte based on photocuring technology and preparation method thereof

Abstract

The invention relates to the technical field of solid electrolyte, in particular to polymer solid electrolyte based on a photocuring technology and a preparation method. The problem that high conductivity and mechanical stability cannot be achieved at the same time in a common technology is solved. The polymer solid electrolyte based on the photocuring technology is composed of a functional component A, a functional component B, a functional component C, a lithium salt and a photoinitiator. By optimizing the formula design of the composite polymer and the photocuring preparation process, the ionic conductivity and the mechanical property of the solid electrolyte are effectively improved, and the prepared composite polymer solid electrolyte film has excellent electrochemical stability and cycle performance; and a technical support is provided for the application of the high-performance lithium metal battery.

Description

Technical Field

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

[0002] The application of solid electrolytes in lithium metal batteries has the following significant advantages: their high safety can reduce the risk of leakage and combustion of traditional liquid electrolytes; high energy density supports lithium metal anodes to achieve higher capacity; in addition, the growth of lithium dendrites can be effectively inhibited by optimizing the solid electrolyte interface. However, current solid polymer electrolytes face challenges in balancing ionic conductivity and mechanical properties, which significantly limits their large-scale application in actual lithium batteries. Existing photocuring technology provides an efficient way to prepare solid polymer electrolytes with excellent performance, but most related technologies are still in the laboratory stage and have not yet formed a systematic solution. In addition, the market demand for solid electrolytes with high conductivity and mechanical stability is becoming increasingly urgent, and existing technologies are difficult to meet both performance requirements at the same time.

[0003] Composite polymer solid electrolyte is a new type of material that has attracted much attention. It is widely used in the field of energy storage due to its high safety, high ionic conductivity and interface stability. Although its application in lithium metal batteries has shown excellent performance, the balance between ionic conductivity and mechanical properties remains an important challenge. Due to the limited ion migration capacity of traditional solid polymer electrolytes and the difficulty of mechanical properties to meet the requirements of high energy density and safety at the same time,

[0004] Therefore, it is urgent to propose a polymer solid electrolyte 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 high conductivity and mechanical stability formed by conventional technologies cannot be achieved at the same time. A brief overview 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 overview is not an exhaustive overview 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 polymer solid electrolyte based on photocuring technology, wherein the polymer solid electrolyte based on photocuring technology is composed of functional component A, functional component B, functional component C, lithium salt, and photoinitiator;

[0008] The mass fraction of the functional component A is 0.35-0.50 parts, the mass fraction of the functional component B is 0.25-0.40 parts, the mass fraction of the functional component C is 0.15-0.30 parts, the mass fraction of the lithium salt is 0.03-0.04 parts, and the mass fraction of the photoinitiator is 0.01-0.05 parts.

[0009] Preferably, the functional component A is 2,2,2-trifluoroethyl acrylate.

[0010] Preferably, the functional component B is vinyl carbonate.

[0011] Preferably, the functional component C is methoxy polyethylene glycol methacrylate.

[0012] Preferred: The lithium salt is lithium bis(trifluoromethanesulfonyl)imide.

[0013] Preferred: The photoinitiator is dimethyl methylphosphonate.

[0014] A method for preparing a polymer solid electrolyte based on photocuring technology comprises the following steps:

[0015] Step 1: Mix 2,2,2-trifluoroethyl acrylate, vinyl carbonate, and methoxy polyethylene glycol methacrylate, add lithium salt to adjust the molar ratio to 8, add a photoinitiator, and stir evenly to form a slurry;

[0016] Step 2: Casting the slurry into a polytetrafluoroethylene mold through a vacuum packaging machine to form a film;

[0017] 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;

[0018] Step 4: Post-process the cured film to ensure uniform film size and avoid residual solvent affecting its performance.

[0019] Preferably, in step 1, the stirring temperature is 40° C., the stirring rate is 300 r / min, and the stirring time is 30 min.

[0020] Preferably, the film thickness is 100-150 μm.

[0021] Preferably: the intensity of the UV light source is 125 mW / cm 2 , the irradiation time is 10min.

[0022] The present invention has the following beneficial effects:

[0023] The present invention effectively improves the ionic conductivity and mechanical properties of the solid electrolyte by optimizing the formula design of the composite polymer and the photocuring preparation process;

[0024] The composite polymer solid electrolyte film prepared by the present invention has excellent electrochemical stability and cycle performance, and provides technical support for the application of high-performance lithium metal batteries. DETAILED DESCRIPTION

[0025] 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.

[0026] Specific implementation method 1: In this implementation method, a polymer solid electrolyte based on photocuring technology is used. The polymer solid electrolyte based on photocuring technology is composed of functional component A, functional component B, functional component C, lithium salt, and photoinitiator;

[0027] The mass fraction of the functional component A is 0.35-0.50 parts, the mass fraction of the functional component B is 0.25-0.40 parts, the mass fraction of the functional component C is 0.15-0.30 parts, the mass fraction of the lithium salt is 0.03-0.04 parts, and the mass fraction of the photoinitiator is 0.01-0.05 parts.

[0028] The design of this polymer solid electrolyte is based on photocuring technology, which uses the synergistic effect of different functional components to achieve high conductivity, excellent mechanical properties and good stability, and is suitable for efficient lithium-ion batteries or other related battery systems. The advantage of this material is that it can be quickly manufactured and shaped by photocuring technology, and it is easy to adjust the composition to optimize performance.

[0029] Specific implementation method 2: In this implementation method, a polymer solid electrolyte based on photocuring technology is used, and the functional component A is 2,2,2-trifluoroethyl acrylate, which has high oxidation stability and interface compatibility and is used to improve the chemical stability and mechanical properties of the electrolyte film.

[0030] Specific implementation method three: In this implementation method, a polymer solid electrolyte based on photocuring technology is used, and the functional component B is vinyl carbonate, which promotes the dissociation of lithium salt through its high polar groups, thereby improving the ion migration ability.

[0031] Vinyl carbonate as functional component B in polymer solid electrolytes using photocuring technology can significantly improve the electrolyte's ionic conductivity, thermal stability, electrochemical stability and interface compatibility, while enhancing the efficiency of the photocuring process. These advantages make it play an important role in solid-state battery applications, especially in improving battery performance and long-term stability.

[0032] Specific implementation method 4: In this implementation method, a polymer solid electrolyte based on photocuring technology is used, and the functional component C is methoxy polyethylene glycol methacrylate, which effectively improves the ionic conductivity of the electrolyte by enhancing the flexibility of the chain segments and lowering the glass transition temperature.

[0033] The molecular weight of methoxy polyethylene glycol methacrylate is 276.

[0034] As the functional component C in the photocuring technology, oxypolyethylene glycol methacrylate provides many advantages in polymer solid electrolytes, including improving the ionic conductivity of the electrolyte, enhancing the photocuring efficiency, improving the mechanical strength and flexibility, improving the thermal stability and electrochemical stability of the electrolyte, and optimizing the interface compatibility between the electrolyte and the electrode. By adjusting its structure, the overall performance of the solid electrolyte can be optimized as needed, making it more suitable for the application of high-performance batteries.

[0035] Specific implementation method 5: In this implementation method, a polymer solid electrolyte based on photocuring technology is used, and the lithium salt is lithium bis(trifluoromethanesulfonyl)imide.

[0036] When lithium bis(trifluoromethanesulfonyl)imide is used as a lithium salt in photocurable polymer solid electrolytes, it can significantly improve the ionic conductivity, electrochemical stability and thermal stability of the electrolyte. At the same time, it also has a positive impact on the compatibility of the photocuring process, the optimization of interface properties and the cycle stability of the battery. Due to these excellent properties of LiTFSI, it has become an important component of photocurable polymer solid electrolytes, especially suitable for high-performance solid-state lithium-ion battery applications.

[0037] Specific implementation method 6: In this implementation method, a polymer solid electrolyte based on photocuring technology is used, and the photoinitiator is dimethyl methyl phosphonate, which is used to ensure rapid curing efficiency and reduce preparation costs.

[0038] As a photoinitiator, dimethyl methylphosphonate can effectively improve the curing efficiency, improve the mechanical properties of the electrolyte membrane, enhance the electrochemical stability and optimize the ionic conductivity. The initiation of DMMP helps the cross-linking of the polymer, improves the density and uniformity of the electrolyte membrane, and enhances the safety and long life of the battery. This makes DMMP an ideal photoinitiator and is widely used in the preparation of photocurable polymer solid electrolytes.

[0039] Specific implementation method 7: A method for preparing a polymer solid electrolyte based on photocuring technology in this implementation method includes the following steps:

[0040] Step 1: Mix 2,2,2-trifluoroethyl acrylate, vinyl carbonate, and methoxy polyethylene glycol methacrylate, add lithium salt to adjust the molar ratio to 8, add a photoinitiator, and stir evenly to form a slurry;

[0041] Step 2: Casting the slurry into a polytetrafluoroethylene mold through a vacuum packaging machine to form a film;

[0042] 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;

[0043] Step 4: Post-process the cured film to ensure uniform film size and avoid residual solvent affecting its performance.

[0044] Optimum: Setting the casting temperature to 40°C can maintain the proper fluidity of the slurry while avoiding the negative effects of high temperature. This temperature condition ensures the uniformity, stability and quality of the film, and provides the best preliminary preparation for the subsequent UV curing reaction.

[0045] This preparation method uses photocuring technology to prepare polymer solid electrolyte film, which not only has excellent ionic conductivity and mechanical strength, but also can improve production efficiency and reduce environmental impact. It has broad application prospects, especially in high-demand fields such as solid-state batteries.

[0046] Specific implementation example eight: In the present implementation example, a method for preparing a polymer solid electrolyte based on a photocuring technology, in step one, the stirring temperature is 40° C., the stirring rate is 300 r / min, and the stirring time is 30 min.

[0047] The stirring conditions in step 1 provide the necessary preliminary preparation for the preparation of uniform and stable polymer solid electrolytes. These conditions ensure the full dissolution and uniform dispersion of various components in the slurry, thus laying the foundation for the subsequent casting and photocuring steps, ensuring that the final prepared solid electrolyte has good performance and consistency.

[0048] Specific implementation method 9: This implementation method is a method for preparing a polymer solid electrolyte based on photocuring technology, and the film thickness is 100-150 μm.

[0049] Film thicknesses in the range of 100-150 μm are ideal for preparing polymer solid electrolytes based on photocuring technology. This thickness can maintain appropriate ionic conductivity and ensure the mechanical stability of the electrolyte, which is suitable for electrochemical devices such as batteries. By precisely controlling process parameters such as casting and photocuring, the uniformity and high performance of the film can be ensured.

[0050] Specific embodiment 10: In this embodiment, a method for preparing a polymer solid electrolyte based on photocuring technology, the intensity of the ultraviolet light source is 125mW / cm 2 , irradiation time is 10min, which can effectively improve the ionic conductivity, mechanical strength and thermal stability of the electrolyte membrane. The key influencing factors include the intensity of the UV light source, irradiation time, the choice of photoinitiator and the thickness of the film. These factors need to be precisely controlled to ensure that the performance of the electrolyte meets the application requirements.

[0051] Example 1

[0052] A method for preparing a polymer solid electrolyte based on photocuring technology comprises the following steps:

[0053] Step 1: Weigh 0.45 g of 2,2,2-trifluoroethyl acrylate (TFEA), 0.30 g of vinyl carbonate (VC), 0.20 g of methoxy polyethylene glycol methacrylate (PEGMMA), 0.03 g of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), and 0.01 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;

[0054] 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;

[0055] 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;

[0056] Step 4: Post-processing of the cured film, including trimming and drying, to ensure uniform film size and avoid residual solvent affecting its performance.

[0057] Example 2

[0058] A method for preparing a polymer solid electrolyte based on photocuring technology comprises the following steps:

[0059] Step 1: Weigh 0.40 g of 2,2,2-trifluoroethyl acrylate (TFEA), 0.30 g of vinyl carbonate (VC), 0.20 g of methoxy polyethylene glycol methacrylate (PEGMMA), 0.04 g of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), and 0.01 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 to ensure that the slurry is uniform;

[0060] 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;

[0061] 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;

[0062] Step 4: Post-processing of the cured film, including trimming and drying, to ensure uniform film size and avoid residual solvent affecting its performance.

[0063] Example 3

[0064] This embodiment optimizes film performance by reducing the amount of photoinitiator used.

[0065] A method for preparing a polymer solid electrolyte based on photocuring technology comprises the following steps:

[0066] Step 1: Weigh 0.45 g of 2,2,2-trifluoroethyl acrylate (TFEA), 0.30 g of vinyl carbonate (VC), 0.15 g of methoxy polyethylene glycol methacrylate (PEGMMA), 0.03 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 200 r / min until a uniform slurry is formed;

[0067] 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;

[0068] 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;

[0069] Step 4: Post-processing of the cured film, including trimming and drying, to ensure uniform film size and avoid residual solvent affecting its performance.

[0070] Example 4

[0071] In this embodiment, the mechanical properties of the film are optimized by adjusting the TFEA ratio.

[0072] A method for preparing a polymer solid electrolyte based on photocuring technology comprises the following steps:

[0073] Step 1: Weigh 0.50 g of 2,2,2-trifluoroethyl acrylate (TFEA), 0.25 g of vinyl carbonate (VC), 0.15 g of methoxy polyethylene glycol methacrylate (PEGMMA), 0.03 g of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), and 0.01 g of dimethyl methylphosphonate (DMPP), add all the components into a mixing container, and stir at 40 ° C for 30 minutes to ensure that the slurry is uniform;

[0074] 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;

[0075] 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;

[0076] Step 4: Post-processing of the cured film, including trimming and drying, to ensure uniform film size and avoid residual solvent affecting its performance.

[0077] Example 5

[0078] In this embodiment, the flexibility and ion migration ability of the film are optimized by increasing the proportion of PEGMMA.

[0079] A method for preparing a polymer solid electrolyte based on photocuring technology comprises the following steps:

[0080] Step 1: Weigh 0.35 g of 2,2,2-trifluoroethyl acrylate (TFEA), 0.25 g of vinyl carbonate (VC), 0.30 g of methoxy polyethylene glycol methacrylate (PEGMMA), 0.03 g of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), and 0.01 g of dimethyl methylphosphonate (DMPP), add all the components into a mixing container, and stir at 40 ° C for 40 minutes at a stirring speed of 300 r / min to ensure uniformity;

[0081] 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;

[0082] 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;

[0083] Step 4: Post-processing of the cured film, including trimming and drying, to ensure uniform film size and avoid residual solvent affecting its performance.

[0084] Example 6

[0085] This embodiment optimizes the polarity of the film and the lithium salt dissociation ability by increasing the VC ratio.

[0086] A method for preparing a polymer solid electrolyte based on photocuring technology comprises the following steps:

[0087] Step 1: Weigh 0.35 g of 2,2,2-trifluoroethyl acrylate (TFEA), 0.40 g of vinyl carbonate (VC), 0.15 g of methoxy polyethylene glycol methacrylate (PEGMMA), 0.03 g of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), and 0.01 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 to ensure that the slurry is uniform;

[0088] 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;

[0089] 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;

[0090] Step 4: Post-processing of the cured film, including trimming and drying, to ensure uniform film size and avoid residual solvent affecting its performance.

[0091] The performance of the polymer solid electrolyte films prepared in Examples 1 to 6 based on the photocuring technology was tested, and the results are shown in the following table:

[0092]

[0093] 1. Electrochemical Impedance Spectroscopy

[0094] 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 5 and Example 6 reached 1.46×10-4S / cm and 1.49×10-4S / cm, respectively, which was significantly higher than that of other samples. This is attributed to the high segment flexibility provided by methoxy polyethylene glycol methacrylate (PEGMMA) and the strong polar lithium salt dissociation effect of vinyl carbonate (VC) side chain. In addition, the optimized TFEA content further improved the ion migration capacity.

[0095] 2. Mechanical properties test

[0096] 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 PEGMMA optimized the flexibility of the film, while VC provided mechanical support, thereby achieving toughness and balance.

[0097] 3. Linear Sweep Voltammetry

[0098] The starting oxidation potential of the samples was tested using linear sweep voltammetry (LSV) with a voltage range of 0 to 7 V. The starting oxidation potential of Examples 5 and 6 reached 4.97 V, showing extremely high antioxidant capacity. This is mainly attributed to the electrochemical stability of the CF bond in the TFEA side chain.

[0099] From the results in the above table, it can be seen that Examples 5 and 6 perform best in ionic conductivity, mechanical properties and electrochemical stability. This shows that by optimizing the formula and process, a good balance can be achieved between ion migration ability and mechanical properties. In general, the composite polymer solid electrolyte film prepared in this study exhibits excellent comprehensive performance, especially in Examples 5 and 6, the best results were achieved. This provides important technical support for the development of a new generation of high-performance solid-state lithium metal batteries.

[0100] 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.

[0101] 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 polymer solid electrolyte based on photocuring technology, characterized in that: The polymer solid electrolyte based on photocuring technology is composed of functional component A, functional component B, functional component C, lithium salt and photoinitiator; The mass fraction of the functional component A is 0.35-0.50 parts, the mass fraction of the functional component B is 0.25-0.40 parts, the mass fraction of the functional component C is 0.15-0.30 parts, the mass fraction of the lithium salt is 0.03-0.04 parts, and the mass fraction of the photoinitiator is 0.01-0.05 parts.

2. The polymer solid electrolyte based on photocuring technology according to claim 1, characterized in that: The functional component A is 2,2,2-trifluoroethyl acrylate.

3. The polymer solid electrolyte based on photocuring technology according to claim 1, characterized in that: The functional component B is vinyl carbonate.

4. The polymer solid electrolyte based on photocuring technology according to claim 1, characterized in that: The functional component C is methoxy polyethylene glycol methacrylate.

5. The polymer solid electrolyte based on photocuring technology according to claim 1, characterized in that: The lithium salt is lithium bis(trifluoromethanesulfonyl)imide.

6. The polymer solid electrolyte based on photocuring technology according to claim 1, characterized in that: The photoinitiator was dimethyl methylphosphonate.

7. A method for preparing a polymer solid electrolyte based on photocuring technology, characterized in that: The steps include: Step 1: Mix 2,2,2-trifluoroethyl acrylate, vinyl carbonate, and methoxy polyethylene glycol methacrylate, add lithium salt to adjust the molar ratio to 8, add a photoinitiator, and stir evenly to form a 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.

8. The method for preparing a polymer solid electrolyte based on photocuring technology according to claim 7, characterized in that: In step 1, the stirring temperature is 40° C., the stirring rate is 300 r / min, and the stirring time is 30 min.

9. The method for preparing a polymer solid electrolyte based on photocuring technology according to claim 7, characterized in that: The film thickness is 100-150 μm.

10. The method for preparing a polymer solid electrolyte based on photocuring technology according to claim 7, characterized in that: The intensity of the UV light source is 125mW / cm 2 , the irradiation time is 10min.

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