A three-dimensional structure ceramic-polymer composite solid electrolyte and a preparation method thereof

Abstract

The application discloses a kind of three-dimensional structure ceramic-polymer composite solid electrolyte and preparation method thereof, belong to lithium ion battery solid electrolyte technical field.The solid electrolyte includes three-dimensional structure ceramic and polymer composite;Three-dimensional structure ceramic is the oxide type ceramic electrolyte with three-dimensional structure, it is one of LLTO, LLZO and LATP;Polymer composite includes the polymer, lithium salt, nitrile and phenoxy resin with mass ratio (30-50):(10-25):(10-20):(1-5).By three-dimensional structure ceramic and polymer composite are compounded, ceramic-based or polymer-based solid electrolyte can be very simply and effectively regulated to form, significantly improve the interface contact state of inorganic and polymer, ion conductivity is high, phenoxy resin can significantly improve the toughness of material, and mechanical stability is high.

Description

Technical Field

[0001] This invention belongs to the field of solid electrolyte technology for lithium-ion batteries, specifically relating to a three-dimensional ceramic-polymer composite solid electrolyte and its preparation method. Background Technology

[0002] With the arrival of the energy crisis and the increasing awareness of environmental protection, new energy vehicles have received unprecedented attention. However, existing liquid lithium-ion batteries, due to their use of liquid organic electrolytes, are prone to fire and explosion risks, and their safety has not been completely resolved. Furthermore, the energy density of current liquid lithium-ion batteries has reached its limit and cannot be further improved, resulting in the unresolved issue of driving range for new energy vehicles. Solid-state batteries, on the other hand, do not contain liquid electrolytes, thus significantly improving safety and greatly increasing energy density, making them the mainstream direction for the future development of rechargeable lithium-ion batteries.

[0003] Existing solid-state electrolytes are mainly divided into polymer solid-state electrolytes and inorganic solid-state electrolytes. Polymer solid-state electrolytes have advantages such as good flexibility, low cost, and ease of large-scale processing and molding, but their very low ionic conductivity at room temperature limits their application. Inorganic solid-state electrolytes include oxide solid-state electrolytes, sulfide solid-state electrolytes, and halide electrolytes. Among them, oxide solid-state electrolytes have high chemical stability, high electrochemical stability, good mechanical strength, and high electrochemical oxidation potential. However, because the contact between inorganic solid-state electrolytes and electrodes is a solid-solid contact, especially oxides which have very high rigidity, the contact state with the positive and negative electrodes is very poor. During charge and discharge, the contact easily changes from surface contact to point contact, which seriously affects the charge and discharge performance of the battery. At the same time, due to the rigid structure of oxides, electrolyte membranes cannot be fabricated on a large scale, and composites are required for application. Therefore, the composite of polymer solid-state electrolytes and inorganic solid-state electrolytes has attracted widespread attention. The composite can solve the problem of low ionic conductivity of polymer solid-state electrolytes and the problem of insufficient structural toughness of inorganic solid-state electrolytes, significantly improving the interfacial contact problem. Summary of the Invention

[0004] One of the objectives of this invention is to provide a three-dimensional ceramic-polymer composite solid electrolyte to solve the problem of low ionic conductivity in solid electrolytes;

[0005] The second objective of this invention is to provide a method for preparing a three-dimensional ceramic-polymer composite solid electrolyte to improve the interfacial contact problem between polymer solid electrolytes and inorganic solid electrolytes.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] In a first aspect, a three-dimensional ceramic-polymer composite solid electrolyte comprises a three-dimensional ceramic and a polymer composite.

[0008] The three-dimensional ceramic is an oxide-type ceramic electrolyte with a three-dimensional structure. The ceramic electrolyte is one of LLTO (lithium lanthanum titanium oxide) ceramic, LLZO (lithium lanthanum zirconium oxide) ceramic, and LATP (lithium titanium aluminum phosphate) ceramic.

[0009] The polymer composite comprises polymers, lithium salts, nitrile compounds, and phenoxy resins.

[0010] Furthermore, the polymer includes one or more of polyethylene oxide, polyvinylidene fluoride, polymethyl methacrylate, polyvinylidene fluoride cohexafluoropropylene, polyurethane acrylate, and polyethylene glycol.

[0011] Furthermore, the lithium salt includes one or two of lithium halides (LiX, X = F, Cl, Br, I), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium perchlorate (LiClO4), lithium hexafluorophosphate (LiPF6), and lithium tetrafluoroborate (LiBF4).

[0012] Furthermore, the nitrile includes one or two of succinic anhydride, adiponitrile, and phenylacetonitrile.

[0013] Secondly, a method for preparing a three-dimensional ceramic-polymer composite solid electrolyte includes the following steps:

[0014] S1: A composite slurry of ceramic electrolyte and epoxy resin is coated to obtain a film;

[0015] S2: Imprinting is performed on the adhesive film to obtain an imprinted adhesive film;

[0016] S3: Sinter the imprinted adhesive film to obtain a three-dimensional ceramic structure;

[0017] S4: Prepare a polymer composite system solution and blend it with a three-dimensional structured ceramic to obtain a three-dimensional structured ceramic-polymer composite solid electrolyte.

[0018] Furthermore, the mass ratio of ceramic electrolyte to epoxy resin in S1 is (5-15):(2.5-30).

[0019] Furthermore, the epoxy resin in S1 is a mixture of bisphenol A epoxy resin and bisphenol F epoxy resin in a mass ratio of (2-20):(0.5-10).

[0020] Furthermore, the epoxy value of the bisphenol A epoxy resin is 0.001-0.5, and preferably, the epoxy value of the bisphenol A epoxy resin is 0.02-0.09.

[0021] Furthermore, the coating process in S1 specifically involves: using a PET substrate (base film) with a thickness of 50 μm, coating a composite slurry of ceramic electrolyte and epoxy resin onto the substrate through a slit, drying to obtain a composite adhesive film, and peeling off the substrate to obtain the adhesive film.

[0022] Furthermore, the thickness of the adhesive film is 10-100 μm, and preferably, the thickness of the adhesive film is 20-50 μm.

[0023] Furthermore, S1 also includes:

[0024] S1-1: Preparation of oxygen ceramic electrolyte slurry: Dissolve the ceramic electrolyte in a solvent and crush it to obtain the ceramic electrolyte slurry; the crushing method includes, but is not limited to, high-energy ball milling or sand milling;

[0025] S1-2: Preparation of composite slurry of ceramic electrolyte and epoxy resin: Mix ceramic electrolyte slurry and epoxy resin evenly to obtain composite slurry of ceramic electrolyte and epoxy resin.

[0026] Furthermore, in S2, the embossing template is a nickel metal template with regularly shaped protrusions on its surface; the shapes of the protrusions include, but are not limited to, hexagons, triangles, quadrilaterals, or circles.

[0027] Furthermore, the height of the protrusion is 10-50 μm, preferably 10-20 μm; the spacing between the protrusions is 5-20 μm, preferably 5-10 μm.

[0028] Furthermore, in S2, the imprinting temperature is 30-100℃, preferably 30-60℃; the imprinting speed is 1-20cm / min, preferably 1-5cm / min.

[0029] Furthermore, in S3, the sintering temperature is 500-950℃ and the sintering time is 1-10h.

[0030] Furthermore, in step S4, the polymer composite system solution is prepared by the following steps: dissolving the polymer, lithium salt, nitrile and phenoxy resin in a solvent at a mass ratio of (30-50):(10-25):(10-20):(1-5), mixing them evenly to obtain the polymer composite system solution.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] 1. This invention provides a three-dimensional ceramic-polymer composite solid electrolyte and its preparation method. By combining the three-dimensional ceramic with the polymer composite, the formation of ceramic-based or polymer-based solid electrolyte can be controlled very simply and effectively. This significantly improves the interfacial contact state between inorganic materials and polymers, resulting in high ionic conductivity. Phenoxy resin can significantly improve the toughness of the material and high mechanical stability.

[0033] 2. This invention obtains a ceramic electrolyte / epoxy resin film with controllable thickness by grinding the ceramic electrolyte into micro-nano-scale particles, mixing it with epoxy resin, and then coating it. By controlling the type of bisphenol A epoxy resin and the ratio of bisphenol F epoxy resin in the epoxy resin, the film can be made into a solid structure at room temperature (25-30℃), which can be easily unwound and rewound. At the same time, since the epoxy resin can very well wet inorganic particles, the epoxy resin and ceramic particles in the dried film can be fully wrapped together.

[0034] 3. By using an imprinting method, controllable imprinting of the ceramic electrolyte / epoxy resin film can be achieved, allowing the film surface to replicate the pattern of the template to form regular and controllable pores. Combined with the sintering process, a three-dimensional ceramic electrolyte framework with regular pores can be formed. This rich three-dimensional framework is beneficial for subsequent filling with polymer solution, forming a tightly contacted ceramic / polymer composite electrolyte. Attached Figure Description

[0035] The present invention will now be further described with reference to the accompanying drawings.

[0036] Figure 1 This is a schematic diagram of the preparation process of a three-dimensional ceramic-polymer composite solid electrolyte according to the present invention;

[0037] Figure 2 This is the impedance spectrum of the three-dimensional ceramic-polymer composite solid electrolyte prepared in Example 1 of this invention;

[0038] Figure 3 The linear sweep voltammetry curve of the three-dimensional ceramic-polymer composite solid electrolyte prepared in Example 1 of this invention is shown.

[0039] Figure 4 This is a stress-strain curve of the three-dimensional ceramic-polymer composite solid electrolyte prepared according to Example 1 of the present invention. Detailed Implementation

[0040] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0041] In this invention, there are no special requirements for the drying process of the coating process. Any known drying process can be used in this application without departing from the inventive concept. Drying can be carried out by electric heating, infrared heating, forced-air heating, etc. It is understood that the drying temperature, drying time, and other related process parameters are not particularly limited in this application. Any technical solution obtained by adjusting parameters without requiring creative effort is within the protection scope of this application, provided it does not depart from the inventive concept.

[0042] Please refer to the schematic diagram of the preparation process of the three-dimensional ceramic-polymer composite solid electrolyte in the following embodiments. Figure 1 .

[0043] Example 1

[0044] A method for preparing a three-dimensional ceramic-polymer composite solid electrolyte includes the following steps:

[0045] S1: Preparation of adhesive film:

[0046] S1-1: Dissolve 10g LLTO in 20g xylene by ball milling, and ball mill for 5 hours at a speed of 500rpm to obtain an LLTO slurry with a D50 of 500nm;

[0047] S1-2: Add 2g of bisphenol A epoxy resin E-06 and 0.5g of bisphenol F epoxy resin 830 to the LLTO slurry, and stir at high speed of 1000rpm for 0.5h to obtain a composite slurry of ceramic electrolyte and epoxy resin.

[0048] S1-3: Using a PET substrate (base film) with a thickness of 50μm, a composite slurry of ceramic electrolyte and epoxy resin is coated onto the substrate through a slit at a coating speed of 3m / min. The composite film is dried at 100℃. The substrate is then peeled off to obtain a film with a thickness of 20μm.

[0049] S2: Design hexagonal protrusions on a nickel metal template. The height of the protrusions is 50μm and the spacing between the protrusions is 5μm. Imprint the adhesive film at a temperature of 30℃ and a speed of 20cm / min. Peel off the template to obtain the imprinted adhesive film.

[0050] S3: The imprinted film is placed in a muffle furnace for sintering at a temperature of 500℃ for 10 hours to obtain a three-dimensional ceramic structure.

[0051] S4: Polyethylene oxide, LiTFSI, succinate, and phenyl resin PKHH were weighed in a mass ratio of 50:25:10:1; Polyethylene oxide, LiTFSI, and succinate were dissolved in 30g xylene, and phenyl resin PKHH was dissolved in 15g butanone beforehand. The two were mixed evenly to obtain a polymer composite system solution; 2g of three-dimensional ceramic was fully immersed in the polymer composite system solution, and after 5h, it was taken out, the excess solution on the surface was absorbed with filter paper, and it was placed at room temperature for 24h. Then it was placed in an oven at 50℃ and dried for another 24h to obtain a three-dimensional ceramic-polymer composite solid electrolyte.

[0052] The mass of the three-dimensional ceramic-polymer composite solid electrolyte obtained after drying was measured to be 12 ± 0.01 g. The mass ratio of the three-dimensional ceramic to the polymer composite was calculated to be 2:10, indicating that this material is a typical three-dimensional ceramic-polymer composite solid electrolyte.

[0053] Example 2

[0054] A method for preparing a three-dimensional ceramic-polymer composite solid electrolyte includes the following steps:

[0055] S1: Preparation of adhesive film:

[0056] S1-1: Dissolve 15g LLTO in 25g xylene by ball milling, and ball mill for 5h at a speed of 1000rpm to obtain an LLTO slurry with a D50 of 300nm;

[0057] S1-2: Add 5g of bisphenol A epoxy resin E-06 and 1g of bisphenol F epoxy resin 830 to the LLTO slurry, and stir at high speed of 1000rpm for 0.5h to obtain a composite slurry of ceramic electrolyte and epoxy resin.

[0058] S1-3: Using a PET substrate (base film) with a thickness of 50μm, a composite slurry of ceramic electrolyte and epoxy resin is coated onto the substrate through a slit at a coating speed of 1m / min. The composite film is dried at 80℃. The substrate is then peeled off to obtain a film with a thickness of 50μm.

[0059] S2: Design hexagonal protrusions on a nickel template. The height of the protrusions is 40μm and the spacing between them is 10μm. Imprint the adhesive film at a temperature of 50℃ and a speed of 10cm / min. Peel off the template to obtain the imprinted adhesive film.

[0060] S3: The imprinted film is placed in a muffle furnace for sintering at a temperature of 950℃ for 1 hour to obtain a three-dimensional ceramic structure.

[0061] S4: Polyvinylidene fluoride, LiTFSI, succinate, and phenyl resin PKHB were weighed in a mass ratio of 30:20:10:5. Polyvinylidene fluoride, LiTFSI, and succinate were dissolved in 25g of xylene, and phenyl resin PKHB was dissolved in 10g of butanone beforehand. The two were mixed evenly to obtain a polymer composite system solution. 5g of three-dimensional ceramic was fully immersed in the polymer composite system solution. After 10h, it was taken out, and the excess solution on the surface was absorbed with filter paper. It was placed at room temperature for 24h, and then placed in an oven at 50℃ for another 24h to continue drying, thus obtaining a three-dimensional ceramic-polymer composite solid electrolyte.

[0062] The mass of the three-dimensional ceramic-polymer composite solid electrolyte obtained after drying was measured to be 7.14 ± 0.01 g. The mass ratio of the three-dimensional ceramic to the polymer composite was calculated to be 7:3, indicating that this material is a typical three-dimensional ceramic-polymer composite solid electrolyte.

[0063] Example 3

[0064] A method for preparing a three-dimensional ceramic-polymer composite solid electrolyte includes the following steps:

[0065] S1: Preparation of adhesive film:

[0066] S1-1: Dissolve 10g LLTO in 15g toluene by sand milling, ball mill for 15h at 1500rpm to obtain LLTO slurry with D50 of 150nm;

[0067] S1-2: Add 20g of bisphenol A epoxy resin E-06 and 10g of bisphenol F epoxy resin 830 to the LLTO slurry, and stir at high speed at 1000rpm for 0.5h to obtain a composite slurry of ceramic electrolyte and epoxy resin.

[0068] S1-3: Using a PET substrate (base film) with a thickness of 50μm, a composite slurry of ceramic electrolyte and epoxy resin is coated onto the substrate through a slit at a coating speed of 3m / min. The composite film is dried at 60℃. The substrate is then peeled off to obtain a film with a thickness of 50μm.

[0069] S2: Design the shape of the protrusions as quadrilaterals on the nickel metal template. The height of the protrusions is 50μm and the spacing between the protrusions is 15μm. Imprint the film with the template at a temperature of 80℃ and a speed of 10cm / min. Peel off the template to obtain the imprinted film.

[0070] S3: The imprinted film is placed in a muffle furnace for sintering at a temperature of 750℃ for 5 hours to obtain a three-dimensional ceramic structure.

[0071] S4: Polymethyl methacrylate, lithium perchlorate, succinic acid, and phenyl resin PKHH were weighed in a mass ratio of 50:10:25:5. Polymethyl methacrylate, lithium perchlorate, and succinic acid were dissolved in 45g of xylene, and phenyl resin PKHH was dissolved in 25g of butanone beforehand. The two were mixed evenly to obtain a polymer composite system solution. 5g of three-dimensional ceramic was fully immersed in the polymer composite system solution. After 5h, it was taken out, and the excess solution on the surface was absorbed with filter paper. It was placed at room temperature for 24h, and then placed in an oven at 50℃ for another 24h to continue drying, thus obtaining a three-dimensional ceramic-polymer composite solid electrolyte.

[0072] The mass of the three-dimensional ceramic-polymer composite solid electrolyte obtained after drying was measured to be 105 ± 0.01 g. The mass ratio of the three-dimensional ceramic to the polymer composite was calculated to be 0.5:10, indicating that this material is a typical three-dimensional ceramic-polymer composite solid electrolyte.

[0073] Example 4

[0074] A method for preparing a three-dimensional ceramic-polymer composite solid electrolyte includes the following steps:

[0075] S1: Preparation of adhesive film:

[0076] S1-1: Dissolve 10g of LATP in 30g of xylene by ball milling, and ball mill for 5 hours at a speed of 2000rpm to obtain an LATP slurry with a D50 of 800nm;

[0077] S1-2: Add 10g of bisphenol A epoxy resin E-06 and 0.5g of bisphenol F epoxy resin 830 to the LATP slurry, and stir at high speed at 1000rpm for 0.5h to obtain a composite slurry of ceramic electrolyte and epoxy resin.

[0078] S1-3: Using a PET substrate (base film) with a thickness of 50μm, a composite slurry of ceramic electrolyte and epoxy resin is coated onto the substrate through a slit at a coating speed of 3m / min. The composite film is dried at 100℃. The substrate is then peeled off to obtain a film with a thickness of 30μm.

[0079] S2: Design hexagonal protrusions on a nickel template. The height of the protrusions is 25μm and the spacing between them is 5μm. Imprint the adhesive film at a temperature of 100℃ and a speed of 20cm / min. Peel off the template to obtain the imprinted adhesive film.

[0080] S3: The imprinted film is placed in a muffle furnace for sintering at a temperature of 750℃ for 5 hours to obtain a three-dimensional ceramic structure.

[0081] S4: Polyvinylidene fluoride cohexafluoropropylene, lithium hexafluorophosphate, phenylacetonitrile, and phenyl resin PKHB are weighed in a mass ratio of 30:10:10:3. Polyvinylidene fluoride cohexafluoropropylene, lithium hexafluorophosphate, and phenylacetonitrile are dissolved in 40g of xylene, and phenyl resin PKHB is dissolved in 25g of butanone beforehand. The two are mixed evenly to obtain a polymer composite system solution. 10g of three-dimensional structured ceramic is fully immersed in the polymer composite system solution. After 1 hour, it is taken out, and the excess solution on the surface is absorbed with filter paper. It is placed at room temperature for 24 hours and then placed in an oven at 50℃ for another 24 hours to continue drying, thus obtaining a three-dimensional structured ceramic-polymer composite solid electrolyte.

[0082] After weighing and drying, the mass of the three-dimensional ceramic-polymer composite solid electrolyte was 12 ± 0.01 g. The mass ratio of the three-dimensional ceramic to the polymer composite was calculated to be 10:2, indicating that this material is a typical three-dimensional ceramic-polymer composite solid electrolyte.

[0083] Example 5

[0084] A method for preparing a three-dimensional ceramic-polymer composite solid electrolyte includes the following steps:

[0085] S1: Preparation of adhesive film:

[0086] S1-1: Dissolve 5g LLTO in 20g xylene by sand milling, ball mill for 5h at 500rpm to obtain LLTO slurry with D50 of 500nm;

[0087] S1-2: Add 2g of bisphenol A epoxy resin E-51 and 1g of bisphenol F epoxy resin 830 to the LLTO slurry, and stir at high speed at 1000rpm for 0.5h to obtain a composite slurry of ceramic electrolyte and epoxy resin.

[0088] S1-3: Using a PET substrate (base film) with a thickness of 50μm, a composite slurry of ceramic electrolyte and epoxy resin is coated onto the substrate through a slit at a coating speed of 2.5m / min. The composite film is dried at 40℃. The substrate is then peeled off to obtain a film with a thickness of 30μm.

[0089] S2: Design hexagonal protrusions on a nickel metal template. The height of the protrusions is 30μm and the spacing between the protrusions is 20μm. Imprint the adhesive film at a temperature of 30℃ and a speed of 15cm / min. Peel off the template to obtain the imprinted adhesive film.

[0090] S3: The imprinted film is placed in a muffle furnace for sintering at a temperature of 650℃ for 3 hours to obtain a three-dimensional ceramic structure.

[0091] S4: Polyethylene oxide, lithium fluoride, phenylacetonitrile, and phenyl resin PKHH were weighed in a mass ratio of 45:25:10:5. Polyethylene oxide, lithium fluoride, and phenylacetonitrile were dissolved in 25g of tetrahydrofuran, and phenyl resin PKHH was dissolved in 25g of butanone beforehand. The two were mixed evenly to obtain a polymer composite system solution. 1g of three-dimensional ceramic was fully immersed in the polymer composite system solution. After 15h, it was taken out, and the excess solution on the surface was absorbed with filter paper. It was placed at room temperature for 24h, and then placed in an oven at 50℃ for another 24h to continue drying, thus obtaining a three-dimensional ceramic-polymer composite solid electrolyte.

[0092] The mass of the three-dimensional ceramic-polymer composite solid electrolyte obtained after drying was measured to be 11 ± 0.01 g. The mass ratio of the three-dimensional ceramic to the polymer composite was calculated to be 1:10, indicating that this material is a typical three-dimensional ceramic-polymer composite solid electrolyte.

[0093] Comparative Example 1

[0094] The difference between this comparative example and Example 1 is that the adhesive film obtained in S1-3 does not undergo the S2 imprinting process, but is directly sintered, while the remaining steps and parameters remain the same.

[0095] Comparative Example 2

[0096] The difference between this comparative example and Example 1 is that phenyl resin PKHH is not added to the polymer composite system in S4, while the remaining steps and parameters remain the same.

[0097] The performance of the solid electrolytes prepared in Examples 1-5 and Comparative Examples 1-2 was tested:

[0098] (I) Ionic Conductivity Test: The AC impedance spectrum of the samples was tested using an Autolab PGSTAR302N electrochemical workstation, and the corresponding particle conductivity was calculated according to the formula. Test Method: In a glove box, the electrolyte impedance R was indirectly obtained by testing with a stainless steel / composite solid electrolyte / stainless steel assembled blocking electrode. The ionic conductivity was tested at 25℃, with a frequency range of 0.1-1MHz and a voltage of 10mV. The ionic conductivity of the electrolyte film can be calculated by the formula: σ=L / (S×R), where L is the thickness of the electrolyte film in cm, and S is the effective contact area between the electrolyte film and the stainless steel sheet in cm². 2 R is the impedance of the electrolyte membrane, in Ω.

[0099] (II) Electrochemical Stability Window: The electrochemical stability window of the sample was tested using an Autolab PGSTAR302N electrochemical workstation. Test method: In a glove box, a button cell was assembled in the following order: negative electrode shell, stainless steel sheet, lithium sheet, composite solid electrolyte, stainless steel sheet, metal spring sheet, and positive electrode shell. The linear sweep voltammetric curve of the electrolyte film in the range of 2.5-5V was recorded at a scan rate of 1mV / s and a test temperature of 25℃.

[0100] (III) Mechanical property testing: The mechanical properties of the electrolyte film were tested using a CMT4104 electronic general-purpose measuring instrument. Test method: The polymer film was cut into strips and fixed between the clamps of a tensile testing machine. The tensile rate was 5 mm / min.

[0101] The performance test results are shown in Table 1.

[0102] Table 1

[0103]

[0104]

[0105] The impedance spectrum of the three-dimensional ceramic-polymer composite solid electrolyte prepared in Example 1 is shown below. Figure 2 As shown, the linear sweep voltammetry curve is as follows: Figure 3 As shown, the stress-strain curve is as follows: Figure 4 As shown.

[0106] The test results above show that, compared with Example 1 and Comparative Example 1, the imprinting process can further improve the ionic conductivity, electrochemical window, mechanical strength, and elongation at break of the composite polymer electrolyte. Comparative Examples 1 and 2 demonstrate that the addition of phenoxy resin can improve the mechanical strength and elongation at break of the material. Examples 2-5 demonstrate that by optimizing experimental conditions, the electrochemical and mechanical properties of the composite solid electrolyte can be adjusted within a wide range.

[0107] 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.

[0108] 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 three-dimensional ceramic-polymer composite solid electrolyte, characterized in that, Including three-dimensional structured ceramics and polymers Complex; The three-dimensional ceramic is an oxide-type ceramic electrolyte with a three-dimensional structure, and the ceramic electrolyte is one of LLTO ceramic, LLZO ceramic and LATP ceramic. The polymer composite comprises polymers, lithium salts, nitrile compounds, and phenoxy resins; The preparation method of the three-dimensional ceramic-polymer composite solid electrolyte includes the following steps: S1: A composite slurry of ceramic electrolyte and epoxy resin is coated to obtain a film with a thickness of 10-100μm. S2: Imprinting is performed on the adhesive film to obtain an imprinted adhesive film; S3: Sinter the imprinted adhesive film to obtain a three-dimensional ceramic structure; S4: Prepare a polymer composite system solution and blend it with a three-dimensional structured ceramic to obtain a three-dimensional structured ceramic-polymer composite solid electrolyte.

2. The three-dimensional ceramic-polymer composite solid electrolyte according to claim 1, characterized in that, The polymer includes one or more of polyethylene oxide, polyvinylidene fluoride, polymethyl methacrylate, polyvinylidene fluoride cohexafluoropropylene, polyurethane acrylate, and polyethylene glycol. And / or, lithium salts include one or two of lithium halides, lithium bis(trifluoromethanesulfonyl)imide, lithium perchlorate, lithium hexafluorophosphate, and lithium tetrafluoroborate; And / or, nitriles include one or two of succinic anhydride, adiponitrile, and phenylacetonitrile.

3. The three-dimensional ceramic-polymer composite solid electrolyte according to claim 1, characterized in that, The mass ratio of ceramic electrolyte to epoxy resin in S1 is (5-15):(2.5-30).

4. The three-dimensional ceramic-polymer composite solid electrolyte according to claim 1, characterized in that, The epoxy resin in S1 is a mixture of bisphenol A epoxy resin and bisphenol F epoxy resin in a mass ratio of (2-20):(0.5-10).

5. The three-dimensional ceramic-polymer composite solid electrolyte according to claim 1, characterized in that, In step S2, the embossing template is a nickel metal template with regularly shaped protrusions on its surface. The protrusions may include, but are not limited to, hexagons, triangles, quadrilaterals, or circles.

6. The three-dimensional ceramic-polymer composite solid electrolyte according to claim 5, characterized in that, The height of the protrusions is 10-50μm, and the spacing between the protrusions is 5-20μm.

7. The three-dimensional ceramic-polymer composite solid electrolyte according to claim 1, characterized in that, In step S2, the imprinting temperature is 30-100℃ and the imprinting speed is 1-20cm / min.

8. The three-dimensional ceramic-polymer composite solid electrolyte according to claim 1, characterized in that, In S3, the sintering temperature is 500-950℃ and the sintering time is 1-10h.

9. The three-dimensional ceramic-polymer composite solid electrolyte according to claim 1, characterized in that, In step S4, the polymer composite system solution is prepared through the following steps: The polymer, lithium salt, nitrile and phenoxy resin were dissolved in a solvent at a mass ratio of (30-50):(10-25):(10-20):(1-5) and mixed evenly to obtain a polymer composite system solution.

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