Binder, clay electrolyte as well as preparation method and application of clay electrolyte

Abstract

The invention discloses a binder, a clay electrolyte as well as a preparation method and application of the clay electrolyte. The binder comprises 100 parts of imidazolium ionic liquid, 1-5 parts of cellulose and 0-5 parts of a plasticizer. The clay electrolyte can be prepared on the basis of the binder, the clay electrolyte can be obtained by kneading after mechanical mixing, and a large-size, ultrathin and high-ionic-conductivity solid electrolyte membrane can be formed by directly rolling subsequently, so that the defects of a dry-method membrane preparation or a wet-method membrane preparation are effectively avoided, and the clay electrolyte is high in ionic conductivity. Compared with the prior art, the electrolyte prepared by the method has soft mechanical properties, is better in contact with an electrode, keeps tight contact between the electrolyte and the electrode without high additional stack pressure (several to hundreds of MPa), and has very important significance for realizing a non-pressure solid-state battery and preparing a solid-state battery with high volume energy density and high mass energy density.

Description

Technical Field

[0001] The present application belongs to the technical field of secondary batteries, and specifically relates to a binder for secondary batteries, as well as a clay electrolyte prepared based on the binder, and a preparation method and application thereof. Background Art

[0002] Solid-state electrolytes (SEs) possess excellent thermal stability, a wide electrochemical window, and inherent safety advantages. They can replace electrolytes to produce high-energy-density and highly safe solid-state batteries. Common inorganic solid electrolytes include oxide solid electrolytes, halide solid electrolytes, and sulfide solid electrolytes. As inactive substances in solid-state batteries, thinner solid electrolyte layers can reduce the inactive content of solid-state lithium batteries, thereby significantly improving the battery's energy density. However, the difficulty in preparing thin films of halide and sulfide solid electrolytes has hindered further improvements in the energy density of all-solid-state batteries.

[0003] The current mainstream methods for preparing solid electrolyte films can be divided into wet and dry methods. Among them, the typical preparation process of the wet method mainly includes three key steps: (1) dispersion: the solid electrolyte and binder are dispersed in a solvent to produce a uniform slurry; (2) film formation: a film is formed from the slurry using wet coating, slot die coating, immersion, casting or similar methods; (3) solvent removal: the solvent is removed from the formed film. Although the wet method is widely used in the preparation of solid electrolyte films and has the advantages of low cost, simplicity and scalability, the wet method still has problems such as high energy consumption and large pollution caused by evaporation of harmful solvents. In addition, inorganic particles are easily agglomerated, resulting in uneven precipitation and stratification in the solid electrolyte membrane; residual polar solvents and binders will lead to structural degradation of the solid electrolyte and reduced ionic conductivity. In addition, halide and sulfide electrolytes are also extremely sensitive to water and polar organic solvents. Only non-polar or weakly polar solvents (such as xylene and toluene) can be used, which will also reduce the ionic conductivity of the electrolyte and limit the choice of binders. In contrast, dry film production uses a deformable binder with good plasticity, significantly reducing the binder ratio and eliminating the disadvantages of using solvents. However, dry film production usually requires hot pressing and has problems such as uneven thickness and brittleness after high pressure.

[0004] From the above, it can be seen that there are certain limitations in the preparation of solid electrolyte membranes, whether it is a wet method or a dry method. Summary of the Invention

[0005] In view of this, the primary purpose of this application is to provide a binder, and based on the binder, a clay electrolyte is provided. The clay electrolyte in this application can be obtained by mechanical mixing and kneading, and can then be directly rolled to form a large-size, ultra-thin and high-ionic conductivity solid electrolyte membrane, thereby effectively avoiding the defects of dry or wet membrane preparation.

[0006] In order to achieve the above objectives, this application adopts the following technical solutions:

[0007] One aspect of the present application discloses a binder, which comprises, by weight, 100 parts of an imidazole ionic liquid, 1 to 5 parts of cellulose, and 0 to 5 parts of a plasticizer.

[0008] Another aspect of the present application discloses a method for preparing a binder, wherein an imidazole ionic liquid, cellulose, and a plasticizer are mixed according to a ratio, heated and stirred at a temperature T until a uniform and transparent slurry is formed, and the binder is obtained after solidification, wherein the temperature T is not lower than the melting point of the imidazole ionic liquid.

[0009] Another aspect of the present application discloses a clay electrolyte comprising the binder, electrolyte salt and inorganic solid electrolyte as described above.

[0010] Another aspect of the present application discloses a solid electrolyte membrane formed by rolling the clay electrolyte described above.

[0011] Another aspect of the present application discloses a solid-state battery comprising the solid-state electrolyte membrane described above.

[0012] Beneficial effects of this application:

[0013] The binder provided in this application can be mechanically mixed and kneaded with any inorganic solid electrolyte to produce a clay electrolyte with clay-like soft mechanical properties. Subsequent roll-pressing can produce a large-scale, ultra-thin solid electrolyte membrane with high ionic conductivity. The entire preparation process is free of free solvents, and the soft mechanical properties of the clay electrolyte do not require high pressure or hot pressing, thus effectively avoiding the drawbacks of separate dry or wet membrane production methods.

[0014] The clay electrolyte obtained in this application has high ionic conductivity and soft mechanical properties, and has better contact with the electrodes. It does not require high additional stack pressure (several to hundreds of MPa) to maintain close contact between the electrolyte and the electrodes. It is of great significance for realizing pressure-free solid-state batteries and preparing solid-state batteries with high volume energy density and high mass energy density.

[0015] In addition, the clay electrolyte in this application also has the advantages of high thermal stability, high temperature resistance and non-flammability, which can further improve the safety of solid-state batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a process of preparing the adhesive slurry and solidifying the adhesive to form the adhesive in a preferred embodiment of the present application.

[0017] Figure 2This is a physical picture of the LIC clay electrolyte HSE-C prepared in Example 1 of the present application.

[0018] Figure 3 This is a diagram showing the soft mechanical properties of the LIC clay electrolyte HSE-C prepared in Example 1 of the present application.

[0019] Figure 4 This is a physical picture of the solid electrolyte membrane obtained by roller pressing the LIC clay electrolyte HSE-C in Example 1 of the present application.

[0020] Figure 5 These are the test results of the ionic conductivity (30° C.) of the clay electrolytes prepared in Examples 1-3 of the present application.

[0021] Figure 6 The impedance of the clay electrolyte HSE-C prepared in Example 1 of the present application at different temperatures ( Figure 6 A) and activation energy ( Figure 6 Middle B) Test results.

[0022] Figure 7 Li||Li symmetric battery with clay electrolyte HSE-C at 0.1 mA·cm -2 Current density, 0.1 mAh cm -2 Cycling performance at capacity density.

[0023] Figure 8 These are the activation energy test results of the clay electrolytes HSE-O and HSE-S prepared in Examples 2 and 3.

[0024] Figure 9 The Li||Li symmetric battery assembled based on the clay electrolyte HSE-O in Example 2 was tested at 0.1 mA·cm -2 Current density, 0.1 mAh cm -2 Cycling performance at capacity density.

[0025] Figure 10 The cycling performance of the LCO||Li full cell assembled based on the clay electrolyte HSE-O in Example 2 at 0.1C. DETAILED DESCRIPTION

[0026] The following will clearly and completely describe the embodiments of the present application. The technical solutions in the embodiments described below are exemplary and are only possible technical implementations of the present application, not all possible implementations. Those skilled in the art can fully combine the embodiments of the present application to obtain other embodiments without creative work, and these embodiments are also within the scope of protection of the present application.

[0027] The first aspect of the present application discloses a binder, which comprises, by weight, 100 parts of an imidazole ionic liquid, 1 to 5 parts of cellulose, and 0 to 5 parts of a plasticizer.

[0028] The binder contains an imidazolium ionic liquid, cellulose, and a plasticizer. Cellulose provides support, while the imidazolium ionic liquid efficiently dissolves cellulose. Furthermore, the cellulose provides plasticity and viscosity to the imidazolium ionic liquid. As a preferred option, a certain amount of plasticizer can be added simultaneously to further enhance the binder's plasticity and viscosity. This binder is used to prepare electrolytes, circumventing the drawbacks of either dry or wet film formation alone, resulting in a clay electrolyte with excellent performance. Specifically, imidazolium ionic liquids are generally solid at room temperature. After being heated to a certain temperature to dissolve cellulose, they become solid upon standing at room temperature, thus possessing the properties of a binder, giving them advantages in dry film formation during subsequent electrolyte preparation. Furthermore, the binder, when combined with the electrolyte, forms a clay-like structure with far greater fluidity than solid particles, thus possessing the characteristics of wet film formation.

[0029] In the present application, the imidazolium ionic liquid refers to a salt composed of an imidazolium cation and an organic / inorganic anion, which is solid at room temperature or near room temperature. This type of imidazolium ionic liquid can be melted into a liquid when heated at a high temperature and can be restored to a solid state when left standing at room temperature. It is a key component of the binder in the present application. Specific examples of the imidazolium ionic liquid include at least one of 1-allyl-3-methylimidazolium chloride (AMIMCl), 1-butyl-3-methylimidazolium chloride (BMImCl), 1-ethyl-3-methylimidazolium acetate (EMImAc), and 1-methyl-3-propylimidazolium chloride (PMImCl), but are not limited thereto. In some examples, the imidazolium ionic liquid is 1-allyl-3-methylimidazolium chloride (AMIMCl), 1-butyl-3-methylimidazolium chloride (BMImCl), or 1-ethyl-3-methylimidazolium acetate (EMImAc).

[0030] In some examples, the cellulose may be plant cellulose or animal cellulose; in other examples, the cellulose may be natural cellulose or a derivative of natural cellulose. As an example, the cellulose is selected from at least one of cotton, chitin, wood cellulose, cellulose powder, and nanocellulose.

[0031] In the present application, the plasticizer is a substance that enhances the viscosity and plasticity of the adhesive. As an example, the plasticizer is preferably succinonitrile (SN), but is not limited thereto.

[0032] The second aspect of the present application discloses a method for preparing the binder described above. Specifically, after mixing the imidazole ionic liquid, cellulose and plasticizer according to the ratio, heating and stirring at a temperature T until a uniform and transparent slurry is formed, and the binder is obtained after solidification, wherein the temperature T is not lower than the melting point of the imidazole ionic liquid.

[0033] When heated at temperature T, the imidazolium ionic liquid melts into a liquid state. After dissolving cellulose, it becomes solid after standing at room temperature or near room temperature, thus having the properties of a binder. In this application, the temperature T is not particularly limited and is specifically set according to the type of imidazolium ionic liquid used. In some examples, the temperature T is between 55 and 100°C, for example, any temperature of 55°C, 60°C, 70°C, 80°C, 90°C, 100°C, or any range therebetween.

[0034] The third aspect of the present application discloses a clay electrolyte comprising the binder, electrolyte salt and inorganic solid electrolyte as described above.

[0035] There is no special restriction on the amount of each component in the clay electrolyte, and those skilled in the art can adjust or select it as needed. In some examples, the mass proportion of each component in the clay electrolyte is: binder 15-30wt%, electrolyte salt 10-30wt%, inorganic solid electrolyte 40-70wt%.

[0036] In the present application, the electrolyte salt is a type commonly used for electrolytes in the art, which can be a lithium salt or a sodium salt. The specific subsequent preparation of different battery types can be designed or selected accordingly.

[0037] In some examples, the electrolyte salt is a lithium salt, and the lithium salt is selected from at least one of lithium bis(trifluoromethylsulfonyl)imide (LiTFSI), lithium difluorooxalatoborate (LiDFOB), lithium hexafluorophosphate (LiPF6), lithium bis(fluorosulfonyl)imide (LiFSI), and lithium bis(oxalatoborate) (LiBOB), but is not limited thereto.

[0038] In other examples, the electrolyte salt is a sodium salt, and the sodium salt is selected from at least one of sodium hexafluorophosphate (NaPF6), sodium bis(fluorosulfonyl)imide (NaFSI), sodium bis(trifluoromethanesulfonyl)imide (NaTFSI), sodium bis(oxalatoborate) (NaBOB), sodium difluorooxalatoborate (NaDFOB), and sodium tetrafluoroborate (NaBF4), but is not limited thereto.

[0039] In the present application, the inorganic solid electrolyte includes at least one of a halide electrolyte, a sulfide solid electrolyte, and an oxide solid electrolyte, without any particular limitation. Any common inorganic solid electrolyte in the art can be used in the present application.

[0040] In some examples, the inorganic solid electrolyte is an oxide electrolyte, and the oxide electrolyte includes at least one of a NASICON-type electrolyte, a perovskite-type electrolyte, an antiperovskite-type electrolyte, a LISICON-type electrolyte, a garnet-type electrolyte, and Na-β-Al2O3.

[0041] In other examples, the inorganic solid electrolyte is a halide electrolyte, and the halide electrolyte includes Li a (M b )X c Y d , wherein M includes at least one of Ga, Y, In, Mg, Sr, Sc, Sn, Pb, Ti, Zr, Hf, Nb, Ta, W, Fe, Ru, Al, and lanthanide metal elements; X includes at least one of halogen elements; Y includes at least one of halide ions, N ions, oxygen-containing anion groups, and pseudohalogen anions; 0.5≤a≤5, 0.2≤b≤4, c+d=a+bm, wherein m is the weighted average valence of the M element, and specific examples that can be mentioned include Li3YCl6, Li3YBr6, Li3ErCl6, Li3YbCl6, Li3InCl6, Li3ScCl6, Li3ZrCl6, Li3TiCl6, Li3TaCl6, Li3ErCl6 or Li3HoCl6, but are not limited thereto.

[0042] In other examples, the inorganic solid electrolyte is a sulfide electrolyte, and the sulfide electrolyte includes Li 6-x PS 5-x Cl 1+x ,0≤x≤0.8, Li2S-P2S5, Li 10 GeP2S 12 , Li3PS4, but is not limited thereto. The sulfide electrolyte may also be at least one of Na3PS4 and Na2SbS4.

[0043] It is understandable that the selection of a specific inorganic solid electrolyte can be selected or adapted accordingly with reference to the specific type of battery. Those skilled in the art have such ability, so there is no special limitation.

[0044] In addition, the clay electrolyte in the present application can be formed by mechanically mixing the components and then kneading them.

[0045] The fourth aspect of the present application discloses a solid electrolyte membrane formed by rolling the clay electrolyte described above. The specific rolling process is a conventional process in the art and will not be described in detail here.

[0046] As an example, the thickness of the solid electrolyte membrane is 20 to 60 μm, for example, it can be any thickness of 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, or a range between any two of them.

[0047] The fifth aspect of the present application discloses a solid-state battery comprising the solid-state electrolyte membrane described above.

[0048] It is understood that the solid-state battery can be a lithium solid-state battery or a sodium solid-state battery. In addition to the solid electrolyte membrane, the solid-state battery also includes a positive electrode and a negative electrode. For example, preferably, the positive electrode and negative electrode are made of sodium or lithium metal or an alloy containing sodium or lithium. This will not be further elaborated here.

[0049] The following are specific embodiments of the present application. It should be noted that the following specific embodiments are only for illustrative purposes and do not limit the scope of the present application in any way.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0051] In addition, unless otherwise specified, methods without specific conditions or steps are conventional methods, and the reagents and materials used are all commercially available.

[0052] Table 1 Composition of clay electrolyte in the embodiment

[0053]

[0054]

[0055] Example 1

[0056] This embodiment discloses a binder and a clay electrolyte prepared based on the binder. The specific composition can be found in Table 1. The preparation steps (all steps are carried out under an inert atmosphere such as Ar) are as follows:

[0057] 1. Preparation of binder

[0058] According to parts by mass, 20 parts of AMIMCl, 1 part of natural cellulose and 1 part of succinonitrile (SN) were mixed, heated and stirred at 80° C. until a uniform and transparent slurry was formed, and the slurry was solidified to obtain a binder.

[0059] In this embodiment, the slurry is coated on a glass plate by a casting method and allowed to stand until the slurry solidifies. Figure 1 .

[0060] 2. Preparation of clay electrolyte

[0061] The obtained binder was uniformly mixed with LiTFSI and Li3InCl6 (LIC) in a mass ratio of 1:1:3 and kneaded into LIC clay electrolyte (denoted as HSE-C in this article). The actual photo is shown in Figure 2 shown.

[0062] Furthermore, after applying a certain pressure to the HSE-C and releasing it, it can be seen that the HSE-C in this embodiment has soft mechanical properties similar to clay ( Figure 3 ).

[0063] 3. Assemble the battery and test it

[0064] The HSE-C prepared in this example was rolled into a solid electrolyte membrane with a thickness of 60 μm. Figure 4 As shown in . And cut into 16mm round pieces.

[0065] The solid electrolyte membrane is placed between two steel gaskets to form an SS||SS symmetrical battery.

[0066] The solid electrolyte membrane is placed between two lithium sheets to make a Li||Li symmetrical battery.

[0067] First, the battery impedance was measured using DHElecCHem, and the lithium ion conductivity of HSE-C was as high as 2.25mS·cm -1 (like Figure 5 The SS||SS symmetrical battery was placed in an oven and kept at different temperatures (40℃, 50℃, 60℃, 70℃, 80℃) for 1h to test the battery impedance. The activation energy of HSE-C was calculated to be 0.21eV (as shown in Figure 6 The Li||Li symmetrical battery was tested using the Xinwei test system. The Li||Li battery was tested at 0.1 mA·cm -2 Current density, 0.1 mAh cm -2 Capacity density is used to test the battery cycle, such as Figure 7 As shown, the cycle time exceeds 200 h, indicating its feasibility in lithium-ion batteries.

[0068] Example 2

[0069] This embodiment discloses a binder and a clay electrolyte prepared based on the binder. The specific composition can be found in Table 1. The preparation steps are as follows:

[0070] 1. Preparation of binder

[0071] According to parts by mass, 20 parts of AMIMCl and 1 part of natural cellulose were taken, heated and stirred at 80° C. until a uniform and transparent slurry was formed, and the slurry was solidified to obtain a binder.

[0072] 2. Preparation of clay electrolyte

[0073] The obtained binder was mixed with LiTFSI, Li 6.4 LqCy 1.4 Ta 0.6 O 12 (LLZTO) were uniformly mixed in a mass ratio of 1:1:2 and kneaded into LLZTO clay electrolyte (denoted as HSE-O in this paper).

[0074] 3. Assemble the battery and test it

[0075] The HSE-O prepared in this example was rolled into a solid electrolyte membrane with a thickness of 60 μm, and then cut into 16 mm discs.

[0076] The solid electrolyte membrane is placed between two steel gaskets to form an SS||SS symmetrical battery.

[0077] The solid electrolyte membrane is placed between two lithium sheets to make a Li||Li symmetrical battery.

[0078] The solid electrolyte membrane was placed on the lithium sheet and the LiCoO2 (LCO) electrode (load 1.5 mg cm -2 ) to make a LCO||Li full battery.

[0079] The battery impedance was measured using DHElecCHem, and the lithium ion conductivity of HSE-O was measured to be 2.17×10 -4 S cm -1 (like Figure 5 As shown), the SS||SS symmetrical battery was placed in an oven and kept at different temperatures (30℃, 40℃, 50℃, 60℃, 70℃, 80℃) for 1h to test the battery impedance. The activation energy of HSE-O was calculated to be 0.41eV, as shown in Figure 8 As shown. The Li||Li symmetric battery was tested, and the Li||Li battery was tested at 0.1 mA·cm -2 Current density, 0.1 mAh cm -2 Capacity density is used to test the battery cycle, such as Figure 9As shown, the stable cycle time is more than 200h. The LCO||Li full battery was tested and the LCO||Li full battery was cycled at 0.1C. Figure 10 shown.

[0080] Example 3

[0081] This embodiment discloses a binder and a clay electrolyte prepared based on the binder. The specific composition can be found in Table 1. The preparation steps are as follows:

[0082] 1. Preparation of binder

[0083] Same as Example 1.

[0084] 2. Preparation of clay electrolyte

[0085] The obtained binder was uniformly mixed with LiTFSI and Li6PS5Cl (LPSC) in a mass ratio of 1:1:2 and kneaded into LPSC clay electrolyte (denoted as HSE-S in this article).

[0086] 3. Assemble the battery and test it

[0087] The HSE-S prepared in this example was rolled into a film and cut into 16 mm round pieces.

[0088] The solid electrolyte membrane is placed between two steel gaskets to form an SS||SS symmetrical battery.

[0089] The solid electrolyte membrane is placed between two lithium sheets to make a Li||Li symmetrical battery.

[0090] The battery impedance was measured using DHElecCHem, and the lithium ion conductivity of HSE-S was measured to be 6.26×10 -4 S cm -1 (like Figure 5 The SS||SS symmetrical cell was placed in an oven and kept at different temperatures (30°C, 40°C, 50°C, 60°C, 70°C, 80°C) for 1 hour to test the cell impedance. The activation energy of HSE-S was calculated to be 0.21 eV, as shown in Figure 8 shown.

[0091] Example 4

[0092] This embodiment discloses a binder and a clay electrolyte prepared based on the binder. The specific composition can be found in Table 1. The preparation steps are as follows:

[0093] 1. Preparation of binder

[0094] The same implementation method as in Example 1 was used, except that AMIMCl was replaced with an equal mass of 1-butyl-3-methylimidazolium chloride (BMImCl).

[0095] 2. Preparation of clay electrolyte

[0096] The obtained binder was evenly mixed with LiTFSI and Li3InCl6 (LIC) in a mass ratio of 1:1:2 and kneaded into LIC clay electrolyte.

[0097] Example 5

[0098] This embodiment discloses a binder and a clay electrolyte prepared based on the binder. The specific composition can be found in Table 1. The preparation steps are as follows:

[0099] 1. Preparation of binder

[0100] The same embodiment as in Example 1 was used, except that AMIMCl was replaced with an equal mass of 1-ethyl-3-methylimidazolium acetate (EMImAc).

[0101] 2. Preparation of clay electrolyte

[0102] The obtained binder was evenly mixed with LiTFSI and Li3InCl6 (LIC) in a mass ratio of 1:1:2 and kneaded into LIC clay electrolyte.

[0103] Example 6

[0104] This embodiment discloses a binder and a clay electrolyte prepared based on the binder. The specific composition can be found in Table 1. The preparation steps are as follows:

[0105] 1. Preparation of binder

[0106] The same implementation method as in Example 1 is used, with the only difference being that the natural cellulose is replaced with cellulose powder of equal mass.

[0107] 2. Preparation of clay electrolyte

[0108] The obtained binder was evenly mixed with LiTFSI and Li3InCl6 (LIC) in a mass ratio of 1:1:2 and kneaded into LIC clay electrolyte.

[0109] Example 7

[0110] This embodiment discloses a binder and a clay electrolyte prepared based on the binder. The specific composition can be found in Table 1. The preparation steps are as follows:

[0111] 1. Preparation of binder

[0112] The same implementation method as in Example 1 is used, except that the natural cellulose is replaced with chitosan of equal mass.

[0113] 2. Preparation of clay electrolyte

[0114] The obtained binder was evenly mixed with LiTFSI and Li3InCl6 (LIC) in a mass ratio of 1:1:2 and kneaded into LIC clay electrolyte.

[0115] Example 8

[0116] This embodiment discloses a binder and a clay electrolyte prepared based on the binder. The specific composition can be found in Table 1. The preparation steps are as follows:

[0117] 1. Preparation of binder

[0118] 100 parts of AMIMCl, 1 part of natural cellulose and 1 part of succinonitrile were mixed according to mass, heated and stirred at 80° C. until a uniform and transparent slurry was formed, and the slurry was solidified to obtain a binder.

[0119] 2. Preparation of clay electrolyte

[0120] The obtained binder was uniformly mixed with LiTFSI and Li3InCl6 (LIC) in a mass ratio of 1:1:2 and kneaded into LIC clay electrolyte.

[0121] Example 9

[0122] This embodiment discloses a binder and a clay electrolyte prepared based on the binder. The specific composition can be found in Table 1. The preparation steps are as follows:

[0123] 1. Preparation of binder

[0124] 100 parts of AMIMCl, 3 parts of natural cellulose and 3 parts of succinonitrile were mixed according to mass, heated and stirred at 80° C. until a uniform and transparent slurry was formed, and the slurry was solidified to obtain a binder.

[0125] 2. Preparation of clay electrolyte

[0126] The obtained binder was evenly mixed with LiTFSI and Li3InCl6 (LIC) in a mass ratio of 1:1:2 and kneaded into LIC clay electrolyte.

[0127] Example 10

[0128] This embodiment discloses a binder and a clay electrolyte prepared based on the binder. The specific composition can be found in Table 1. The preparation steps are as follows:

[0129] 1. Preparation of binder

[0130] Same as Example 1.

[0131] 2. Preparation of clay electrolyte

[0132] The obtained binder was evenly mixed with LiTFSI and Li3InCl6 (LIC) in a mass ratio of 1:1.5:3 and kneaded into LIC clay electrolyte.

[0133] Example 11

[0134] This embodiment discloses a binder and a clay electrolyte prepared based on the binder. The specific composition can be found in Table 1. The preparation steps are as follows:

[0135] 1. Preparation of binder

[0136] Same as Example 1.

[0137] 2. Preparation of clay electrolyte

[0138] The obtained binder was evenly mixed with LiTFSI and Li3InCl6 (LIC) in a mass ratio of 1:0.8:2.5 and kneaded into LIC clay electrolyte.

[0139] Example 12

[0140] This embodiment discloses a binder and a clay electrolyte prepared based on the binder, and the specific steps are as follows:

[0141] 1. Preparation of binder

[0142] Same as Example 1.

[0143] 2. Preparation of clay electrolyte

[0144] The obtained binder was evenly mixed with LiFSI and Li3InCl6 (LIC) in a mass ratio of 1:1:2 and kneaded into LIC clay electrolyte.

[0145] Example 13

[0146] 1. Preparation of binder

[0147] Same as Example 1.

[0148] 2. Preparation of clay electrolyte

[0149] The obtained binder was mixed with NaTFSI, Na 0.7 La 0.7 Zr 0.3 Cl 1.4 (NaLZC) were uniformly mixed in a mass ratio of 1:1:2 and kneaded into NaLZC clay electrolyte.

[0150] Performance Testing

[0151] The clay electrolyte in the example was rolled into a solid electrolyte membrane with a thickness of 60 μm and cut into discs with a diameter of 16 mm. The solid electrolyte membrane was placed between two steel spacers to form an SS||SS symmetrical battery.

[0152] (1) The impedance of the SS||SS symmetrical battery was measured using DHElecCHem, and the lithium ion conductivity of the clay electrolyte was obtained. The results are shown in Table 2.

[0153] Table 2 Clay electrolyte ion conductivity test results

[0154]

[0155]

[0156] (2) The SS||SS symmetrical battery was placed in an oven and kept at different temperatures (40°C, 50°C, 60°C, 70°C, and 80°C) for 1 h. The battery impedance was measured and the activation energy was calculated. The results are shown in Table 3.

[0157] Table 3 Activation energy test results

[0158] Activation energy Ea (eV) Example 1 0.21 Example 2 0.41 Example 3 0.21 Example 10 0.22 Example 11 0.21

[0159] Through Tables 2, 3 and Figure 1-10 It can be seen from the test results that the preparation of the clay electrolyte in this application and the obtained clay electrolyte have high ionic conductivity and low activation energy, which meet the requirements of the cycle test, indicating that the preparation method and the obtained clay electrolyte in this application can be applied to solid-state batteries and have industrial application prospects.

[0160] It should be noted that the present application is not limited to the above-mentioned embodiments. The above-mentioned embodiments are merely examples, and any embodiments having substantially the same structure and effect as the technical concept within the scope of the present application are all included in the technical scope of the present application. In addition, without departing from the scope of the present application, any other embodiments that can be conceived by those skilled in the art and that combine some of the constituent elements in the embodiments are also included in the scope of the present application.

Claims

1. A binder, characterized in that: Calculated by weight, the binder includes 100 parts of imidazole ionic liquid, 1 to 5 parts of cellulose and 0 to 5 parts of plasticizer.

2. The adhesive according to claim 1, wherein The imidazole ionic liquid is selected from at least one of 1-allyl-3-methylimidazole chloride, 1-butyl-3-methylimidazole chloride, 1-ethyl-3-methylimidazole acetate, and 1-methyl-3-propylimidazole chloride.

3. The adhesive according to claim 1, wherein The cellulose is selected from at least one of cotton, chitin, wood cellulose, cellulose powder and nanocellulose.

4. The adhesive according to claim 1, wherein The plasticizer is succinonitrile.

5. A method for preparing the adhesive according to any one of claims 1 to 4, characterized in that: After mixing the imidazole ionic liquid, cellulose and plasticizer according to the ratio, heating and stirring at a temperature T until a uniform and transparent slurry is formed, and solidifying to obtain the binder, wherein the temperature T is not lower than the melting point of the imidazole ionic liquid; Preferably, the temperature T is 55-100°C.

6. A clay electrolyte, characterized in that Containing the binder according to any one of claims 1 to 4, an electrolyte salt and an inorganic solid electrolyte; Preferably, in the clay electrolyte, the mass proportions of the components are: 15-30 wt% of binder, 10-30 wt% of electrolyte salt, and 40-70 wt% of inorganic solid electrolyte.

7. The clay electrolyte according to claim 6, characterized in that The electrolyte salt is a lithium salt or a sodium salt; Preferably, the lithium salt is selected from at least one of lithium bis(trifluoromethylsulfonyl)imide, lithium difluorooxalatoborate, lithium hexafluorophosphate, lithium bis(fluorosulfonyl)imide, and lithium bis(oxalatoborate); Preferably, the sodium salt is selected from at least one of sodium hexafluorophosphate, sodium bis(fluorosulfonyl)imide, sodium bis(trifluoromethanesulfonyl)imide, sodium bis(oxalatoborate), sodium difluorooxalatoborate, and sodium tetrafluoroborate.

8. The clay electrolyte according to claim 6, wherein The inorganic solid electrolyte is one of a halide electrolyte, a sulfide electrolyte or an oxide electrolyte.

9. A solid electrolyte membrane, characterized in that The clay electrolyte according to any one of claims 6 to 8 is rolled and formed; Preferably, the thickness of the solid electrolyte membrane is 20 to 60 μm.

10. A solid-state battery, characterized in that: A solid electrolyte membrane according to claim 9 is included.

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