Binder and preparation method thereof, positive electrode slurry, positive electrode plate, battery and electric equipment

Abstract

The invention discloses a binder and a preparation method thereof, positive pole slurry, a positive pole piece, a battery and electric equipment, the binder comprises a fluorine-containing polyether ionomer, the fluorine-containing polyether ionomer is a copolymer of a fluorine-containing polyether structural unit and a polyion liquid structural unit, the fluorine-containing polyether structural unit comprises a fluorine-containing polyether monomer with an unsaturated carbon-carbon double bond. According to the adhesive disclosed by the invention, the adhesive is easily dissolved in a slurry solvent, side reaction between the adhesive and sulfide can be avoided, and the adhesive has good stability on sulfide solid electrolyte.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a binder and its preparation method, a positive electrode slurry, a positive electrode sheet, a battery, and an electrical device. Background Technology

[0002] The urgent demand for high-range, high-safety power batteries in the passenger vehicle market has spurred the development of solid-state battery technology. In sulfide all-solid-state batteries, the composite cathode slurry composition typically includes active material particles, small-particle-size sulfide solid electrolyte, conductive agent, dispersant, and low-polarity solvent. The use of small-particle-size sulfide solid electrolyte mixed with active material particles aims to improve the poor ionic conductivity within the electrode. However, it often requires the introduction of up to 20%–40% of small-particle-size sulfide solid electrolyte to ensure high ionic conductivity and low polarization in the electrode. This also leads to insufficient adhesion between particles within the composite cathode, which is typically addressed by adding binders to improve particle adhesion.

[0003] The most mature preparation method for composite cathodes is wet processing. However, due to the instability of sulfide electrolyte particles in polar solvents, non-polar or low-polarity organic reagents are commonly used as slurry solvents to avoid side reactions in the sulfide solid electrolyte during wet preparation, which could lead to a decrease in ionic conductivity. However, commonly used binders are difficult or insoluble in these slurry solvents, which is detrimental to the use of cathode slurries. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. Therefore, one object of the present invention is to provide a binder that is readily soluble in slurry solvents, avoids side reactions between the binder and sulfides, and exhibits good stability to sulfide solid electrolytes.

[0005] The second objective of this invention is to provide a method for preparing an adhesive.

[0006] A third objective of this invention is to provide a positive electrode slurry employing the aforementioned binder.

[0007] The fourth objective of this invention is to provide a positive electrode sheet using the above-mentioned positive electrode slurry.

[0008] The fifth object of the present invention is to provide a battery using the above-mentioned positive electrode slurry or positive electrode sheet.

[0009] The sixth object of the present invention is to provide an electrical device using the above-described battery.

[0010] According to an embodiment of the first aspect of the present invention, an adhesive includes a fluorinated polyether ionomer, said fluorinated polyether ionomer being a copolymer of a fluorinated polyether structural unit and a polyionic liquid structural unit, said fluorinated polyether structural unit comprising a fluorinated polyether monomer having unsaturated carbon-carbon double bonds.

[0011] According to embodiments of the present invention, the binder enhances its lipophilicity by using a fluorinated polyether ionomer, and also exhibits good solubility in the aforementioned slurry solvent, thereby facilitating the preparation and use of the positive electrode slurry. Furthermore, the perfluorinated or highly fluorinated structure stabilizes the sulfide solid electrolyte, preventing side reactions between the binder and the sulfide solid electrolyte that could lead to a decline in ionic conductivity, thus ensuring the optimal electrical performance of the positive electrode slurry.

[0012] According to some embodiments of the present invention, the molar ratio of the fluorinated polyether structural unit to the polyionic liquid structural unit is 10:1 to 1:1.

[0013] According to some embodiments of the present invention, the fluorinated polyether monomer is a perfluorinated polyether monomer.

[0014] According to some embodiments of the present invention, the fluorinated polyether structural unit copolymer premonomer comprises a compound having the general chemical formula (1):

[0015] Equation (1), In equation (1), a = 1 - 16, R CC1 The number of carbon atoms ranges from 1 to 6.

[0016] According to some embodiments of the present invention, the premonomer of the polyionic liquid structural unit copolymerization comprises a compound having the chemical formula (2):

[0017] Equation (2), In equation (2), [X + [Y] is a cation with a carbon-carbon double bond. - The cation is an anion, and the cation includes compounds having the general chemical formula (a)-(g):

[0018] Formula (a)-(g), (a)-(g) represent pyridyl cation, piperidinyl cation, pyrroloyl cation, pyrrolidone cation, imidazole cation, quaternary phosphonium cation, and quaternary ammonium cation, respectively, R CC2 The number of carbon atoms is 1-6, R CH1 R CH2 R CH3The number of carbon atoms is independently selected from 1 to 6; the anion is selected from tetrafluorophosphate, bis(trifluoromethanesulfonyl)imide, hexafluorophosphate, bis(fluorosulfonyl)imide, perchlorate, tetrafluoroborate, bis(oxalateborate), difluorooxalateborate, or hexafluoroarsenate.

[0019] According to some embodiments of the present invention, the molar ratio of the copolymerization precursor of the fluorinated polyether structural unit to the copolymerization precursor of the polyionic liquid structural unit is 10:1 to 1:1.

[0020] A method for preparing an adhesive according to a second aspect of the present invention includes the following steps: Solution A is obtained by dissolving a fluorinated polyether monomer in an organic solvent; Solution B is obtained by dissolving the ionic liquid monomer in an organic solvent; Solution B is mixed with solution A to obtain solution C; The reaction vessel was evacuated, and then the solution C was drawn in. The initiator solution is introduced into the reactor, and after reacting at a preset temperature and pressure for a preset time, cooling brine is introduced to terminate the copolymerization reaction. A precipitant is added to the slurry obtained by copolymerization to carry out a precipitation reaction and obtain a precipitated product. The precipitated product is filtered and dried to obtain the adhesive according to the first aspect of the embodiment described above.

[0021] According to some embodiments of the present invention, the reaction at a preset temperature and preset pressure for a preset time further includes: When the actual pressure inside the reactor decreases, the fluorinated polyether monomer and the ionic liquid monomer are added to the reactor, and the pressure inside the reactor is adjusted to maintain the preset pressure. The percentage of the sum of the mass of the fluorinated polyether monomer and the ionic liquid monomer to the mass of the organic solvent is ω, wherein ω satisfies: 10%≤ω≤30%.

[0022] According to some embodiments of the present invention, the preset temperature is T, the preset pressure is P, and the preset time is t, wherein T, P, and t respectively satisfy: 20℃≤T≤60℃, 4MPa≤P≤8MPa, and 4h≤t≤8h.

[0023] According to some embodiments of the present invention, the step of introducing the initiator solution into the reaction vessel includes: using a constant flow pump to introduce the initiator solution into the reaction vessel at a rate of 2 mL / min, and when the actual pressure inside the reaction vessel decreases, adjusting the initiator solution to be introduced into the reaction vessel at a rate of 1 mL / min.

[0024] According to some embodiments of the present invention, the total amount of initiator added to the initiator solvent is 0.001% to 1% of the sum of the mass of the fluorinated polyether monomer and the ionic liquid monomer.

[0025] According to some embodiments of the present invention, the vacuuming process of the reactor includes: filling the reactor with nitrogen gas for gas replacement, performing the vacuuming process, repeating the operation three times, and continuing the vacuuming process of the reactor when the oxygen content in the reactor is detected to be less than 10 ppm.

[0026] According to some embodiments of the present invention, the organic solvent includes acetonitrile, acetone, dimethyl sulfoxide, N,N-dimethylformamide, 1,3-dimethyl-2-imidazolinone, or hexamethylphosphoramide; and / or, the initiator solution is an initiator dissolved in the organic solvent, wherein the initiator includes at least one selected from cumene hydroperoxide, azobisisobutyronitrile, azobisisoheptanenitrile, benzoyl peroxide, dialkyl peroxide, diisopropyl percarbonate, di-n-propyl percarbonate, tert-butyl hydroperoxide, and tert-butyl peroxide benzoate; and / or, the precipitant includes methanol, ethanol, or methyl tert-butyl ether.

[0027] According to some embodiments of the present invention, the filtration and drying of the precipitated product specifically includes: drying the precipitated product in a vacuum oven at 80°C to 100°C for 24 hours.

[0028] The positive electrode slurry according to a third aspect of the present invention includes the binder according to the first aspect of the present invention, or the binder prepared according to the preparation method of the second aspect of the present invention.

[0029] According to a fourth aspect embodiment of the present invention, the positive electrode sheet includes the positive electrode slurry described in the third aspect embodiment above.

[0030] A battery according to a fifth aspect embodiment of the present invention includes a positive electrode slurry as described in the third aspect embodiment above, or a positive electrode sheet as described in the fourth aspect embodiment above.

[0031] An electrical appliance according to a sixth aspect of the present invention includes a battery according to the fifth aspect of the present invention.

[0032] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Detailed Implementation

[0033] The embodiments of the present invention are described in detail below. These embodiments are exemplary, and the binder according to the first aspect of the present invention is described in detail below. In the following description, the binder is used as an example in the positive electrode slurry of an all-solid-state battery.

[0034] The adhesive according to a first aspect of the present invention includes a fluorinated polyether ionomer.

[0035] Specifically, fluorinated polyether ionomers are copolymers of fluorinated polyether structural units and polyionic liquid structural units, wherein the fluorinated polyether structural units include fluorinated polyether monomers having unsaturated carbon-carbon double bonds.

[0036] For example, fluorinated polyether ionomers are obtained by thermally initiating random copolymerization of fluorinated polyether monomers with unsaturated carbon-carbon double bonds and ionic liquid monomers. The fluorinated polyether monomers can be either highly fluorinated or perfluorinated. The higher the fluorine content, the stronger the nonpolarity of the fluorinated polyether monomer.

[0037] The fluorinated polyether monomer used in this application has abundant strongly polar CF covalent bonds, which effectively enhances the chemical inertness of the binder molecules, thereby improving the stability of the binder, especially its antioxidant stability for high-nickel cathode active materials. Furthermore, the fluorinated polyether monomer increases molecular polarizability, which to some extent enhances the lipophilicity of the binder, resulting in good solubility in non-polar or low-polar organic solvents that offer good stability to solid electrolytes. In other words, non-polar or low-polar organic solvents with good stability to solid electrolytes are typically used as slurry solvents in cathode slurry preparation; the binder in this application also exhibits good solubility in these solvents, thus facilitating the preparation and use of the cathode slurry. Moreover, compared to binders containing polar groups such as hydroxyl, ester, and carboxyl groups in traditional technologies, the perfluorinated or highly fluorinated structure stabilizes the sulfide solid electrolyte, preventing side reactions between the binder and the sulfide solid electrolyte that could lead to a decline in ionic conductivity, thereby ensuring the optimal electrical performance of the cathode slurry.

[0038] According to embodiments of the present invention, the binder enhances its lipophilicity by using a fluorinated polyether ionomer, and also exhibits good solubility in the aforementioned slurry solvent, thereby facilitating the preparation and use of the positive electrode slurry. Furthermore, the perfluorinated or highly fluorinated structure stabilizes the sulfide solid electrolyte, preventing side reactions between the binder and the sulfide solid electrolyte that could lead to a decline in ionic conductivity, thus ensuring the optimal electrical performance of the positive electrode slurry.

[0039] According to some embodiments of the present invention, the molar ratio of fluorinated polyether structural units to polyionic liquid structural units is 10:1 to 1:1. For example, when the molar ratio of fluorinated polyether structural units to polyionic liquid structural units is greater than 10:1, the ionic conductivity of the adhesive is poor, resulting in a large interfacial impedance. When the molar ratio of fluorinated polyether structural units to polyionic liquid structural units is less than 1:1, the stability of the adhesive is poor, and it is not conducive to dissolving in nonpolar solvents. Therefore, by setting the molar ratio of fluorinated polyether structural units to polyionic liquid structural units to 10:1 to 1:1, and by setting the amount of fluorinated polyether structural units and polyionic liquid structural units reasonably, it can be ensured that the obtained fluorinated polyether ionomer is obtained by fully copolymerizing the fluorinated polyether monomer and the ionic liquid monomer, thereby improving the antioxidant properties of the adhesive. For example, the fluorinated polyether ionomer is a random copolymer polymer with the molecular structure shown in the following formula (01):

[0040] Equation (01), In formula (01), RF is a fluorinated polyether structural unit and RI is a polyionic liquid structural unit. The molar ratio of the fluorinated polyether structural unit to the ionic liquid structural unit is m:n = 10~1:1.

[0041] According to some embodiments of the present invention, the fluorinated polyether monomer is a perfluorinated polyether monomer. This configuration enhances the molecular polarizability of the binder molecule, thereby improving its lipophilicity and optimizing its solubility in nonpolar or low-polar solvents with good stability to sulfide solid electrolytes. Simultaneously, the perfluorinated structure of the binder molecule provides good stability to the sulfide solid electrolyte, preventing side reactions between the binder and the sulfide and ensuring the ionic conductivity of the sulfide solid electrolyte.

[0042] According to some embodiments of the present invention, the precursor monomer for the copolymerization of the fluorinated polyether structural unit (i.e., the fluorinated polyether monomer) comprises a compound having the general chemical formula (1):

[0043] Equation (1), In equation (1), a = 1 - 16, R CC1 The number of carbon atoms is 1-6. For example, one end of a fluorinated polyether monomer contains at least one or more perfluorinated polyether groups, where a averages 1-16, and the other end of the fluorinated polyether monomer contains an alkyl group R containing an unsaturated carbon-carbon double bond. CC1Therefore, the unsaturated double bonds of the fluorinated polyether structural units formed by the above-mentioned fluorinated polyether monomers can undergo polymerization reactions with the polyionic liquid structural units to generate fluorinated polyether ionomers, thereby giving the adhesive better peel strength, improving the stability of the adhesive and its solubility in the slurry solvent, which is beneficial to the use of the adhesive.

[0044] According to some embodiments of the present invention, the premonomer of the polyionic liquid structural unit copolymerization comprises a compound having the chemical formula (2):

[0045] Equation (2), In equation (2), [X + [Y] is a cation with a carbon-carbon double bond. - [A] is an anion, and cations include compounds having the general chemical formula (a)-(g):

[0046] Formula (a)-(g), (a)-(g) represent pyridyl cation, piperidinyl cation, pyrroloyl cation, pyrrolidone cation, imidazole cation, quaternary phosphonium cation, and quaternary ammonium cation, respectively, R CC2 The number of carbon atoms is 1-6, R CH1 R CH2 R CH3 The number of carbon atoms is independently selected from 1 to 6. The anion is selected from tetrafluorophosphate, bis(trifluoromethanesulfonyl)imide, hexafluorophosphate, bis(fluorosulfonyl)imide, perchlorate, tetrafluoroborate, bis(oxalateborate), difluorooxalateborate, or hexafluoroarsenate.

[0047] In other words, the monomers (i.e., ionic liquid monomers) used as copolymers of polyionic liquid structural units are pyridinium salts, piperidine salts, pyrrole salts, pyrrolidone salts, imidazole salts, quaternary ammonium salts, or quaternary phosphonium salts with carbon-carbon double bonds, and their molecular structures are shown in the above general structural formulas (a)-(g), where [X + [Y] is a cation with a carbon-carbon double bond. - ] is an anion. Wherein, R CC2 An alkyl group containing one unsaturated carbon-carbon double bond, wherein the alkyl group R CC2 The number of carbon atoms is 1~6; R CH1 R CH2 R CH3 The alkane group R is a saturated straight-chain or branched alkane group. CH1 R CH2 R CH3 The number of carbon atoms ranges from 1 to 6.

[0048] This configuration allows the binder molecules of the fluorinated polyether ionomer to possess lithium-ion conductivity due to the ionic liquid segments, thus becoming an ion-conducting polymer, i.e., an ionomer. By uniformly distributing itself among the pores of the component particles, this fluorinated polyether ionomer binder effectively reduces the interfacial contact resistance between solid particles, mitigating the impact of polarization on battery cycle and rate performance, thereby promoting rapid lithium-ion transport kinetics. The addition of this binder reduces the proportion of sulfide solid electrolyte, thereby increasing the active material loading per unit mass of the positive electrode.

[0049] Furthermore, the polyionic liquid structural units in the binder molecules can provide more weak interactions between the binder and component particles, such as electrostatic interactions, π-π interactions, and dipole interactions, thereby enhancing the adhesion of the binder molecules. Simultaneously, the binder is copolymerized under high pressure, resulting in a more branched structure in the binder molecules, which enhances the entanglement ability of the molecular chains. The binder's adhesive ability is optimized, allowing for a reduction in the proportion of binder added while maintaining the positive electrode peel strength, further increasing the loading of active material per unit mass of the positive electrode. In other words, the binder exhibits good adhesion and stability while also possessing good conductivity.

[0050] According to some embodiments of the present invention, the molar ratio of the monomer prior to copolymerization of the fluorinated polyether structural unit to the monomer prior to copolymerization of the polyionic liquid structural unit is 10:1 to 1:1. That is, the fluorinated polyether monomer and the ionic liquid monomer react under preset conditions to generate a fluorinated polyether ionomer comprising both fluorinated polyether structural units and polyionic liquid structural units. Adding the fluorinated polyether monomer and the ionic liquid monomer within the above-specified molar ratio range ensures a reasonable amount of both, which is beneficial to the production of the fluorinated polyether ionomer and guarantees the optimal performance of the fluorinated polyether ionomer.

[0051] A method for preparing an adhesive according to a second aspect of the present invention includes the following steps: Dissolve the fluorinated polyether monomer in an organic solvent to obtain solution A (i.e., the fluorinated polyether monomer solution). The ionic liquid monomer is dissolved in an organic solvent to obtain solution B (i.e., the ionic liquid monomer solution). Solution C (i.e., mixed precursor solution) is prepared by mixing solution B with solution A. The reaction vessel was evacuated, and then the above solution C was drawn in. The initiator solution is introduced into the reactor, and after reacting at a preset temperature and pressure for a preset time, cooling brine is introduced to terminate the copolymerization reaction. A precipitant is added to the slurry obtained by copolymerization to carry out a precipitation reaction and obtain a precipitated product. The precipitated product is filtered and dried to obtain the binder according to the first aspect of the embodiment described above.

[0052] In other words, the fluorinated polyether monomer and the ionic liquid monomer are first prepared into solutions of specific concentrations and then mixed. The mixed fluorinated polyether monomer and ionic liquid monomer will not undergo self-polymerization. After adding the initiator solution and allowing the polymerization reaction to occur under preset temperature and pressure conditions, the binder can be obtained. The preparation method is simple and facilitates control of the reaction.

[0053] According to some embodiments of the present invention, the reaction time at a preset temperature and a preset pressure further includes: when the actual pressure inside the reactor decreases, adding fluorinated polyether monomer and ionic liquid monomer to the reactor, and adjusting the pressure inside the reactor to maintain at a preset pressure, wherein the percentage of the sum of the mass of the fluorinated polyether monomer and the ionic liquid monomer to the mass of the organic solvent is ω, wherein ω satisfies: 10%≤ω≤30%.

[0054] For example, the reactor can be a 10L horizontal reactor equipped with a ribbon agitator. During the reaction, when a pressure drop is observed, perfluoropolyether monomers and ionic liquid monomers are continuously introduced at the same monomer feeding ratio, and the pressure inside the reactor is maintained at a set value, i.e., 4~8MPa, using a regulating valve. The total mass of the added perfluoropolyether monomers and ionic liquid monomers is 10~30% of the mass of the organic solvent. This means that during the reaction, the perfluoropolyether monomers and ionic liquid monomers are consumed as the reaction proceeds, while the amount of organic solvent remains relatively constant. The amount of added perfluoropolyether monomers and ionic liquid monomers is the same as the amount of solutions A and B obtained. By supplementing the perfluoropolyether monomers and ionic liquid monomers during the reaction, the copolymerization reaction can proceed smoothly, ensuring that the polymer formed after full copolymerization of the perfluoropolyether monomers and ionic liquid monomers has a saturated long-chain structure, thus improving the antioxidant properties of the binder. ω is further preferably 15%≤ω≤25%. During the reaction, the total volume of solution introduced is 25-45% of the volume of the reaction vessel. Therefore, the amount of solution added is reasonable and conducive to the smooth progress of the reaction.

[0055] According to some embodiments of the present invention, the preset temperature is T, the preset pressure is P, and the preset time is t, wherein T, P, and t respectively satisfy: 20℃≤T≤60℃, 4MPa≤P≤8MPa, and 4h≤t≤8h.

[0056] To promote the full copolymerization reaction of the perfluoropolyether monomer and the ionic liquid monomer, the reaction is preferably carried out at a lower temperature not exceeding 60°C, with the lower temperature range being 20°C to 60°C, and more preferably 40°C to 50°C. Furthermore, to increase the branching degree of the copolymer and enhance the entanglement and bonding ability of the copolymer binder molecular chains, the copolymerization reaction is preferably carried out at a higher pressure of not less than 4 MPa, with the higher pressure being 4 MPa to 8 MPa, and more preferably 6 MPa to 8 MPa. Therefore, the perfluoropolyether monomer and the ionic liquid monomer are introduced in the same proportion until the pressure in the reactor is controlled to rise above 4 MPa. After introducing the solution to mix the precursor solution, the reactor is stirred, with the ribbon agitator rotating at 40 to 80 rpm to facilitate thorough mixing of the solution. Maintaining the above reaction conditions, after the reaction has proceeded for 4 to 8 hours, the initiator solution is stopped, the feeding of the perfluoropolyether monomer and the ionic liquid monomer is stopped, and the unreacted monomer is discharged into the reactor. After the pressure is reduced to atmospheric pressure, nitrogen is introduced for gas purging.

[0057] According to some embodiments of the present invention, introducing the initiator solution into the reaction vessel includes: using a constant flow pump to introduce the initiator solution into the reaction vessel at a rate of 2 mL / min; when the actual pressure inside the reaction vessel decreases, adjusting the initiator solution to be introduced into the reaction vessel at a rate of 1 mL / min. The total amount of initiator added to the initiator solvent is 0.001% to 1% of the sum of the mass of the fluorinated polyether monomer and the ionic liquid monomer.

[0058] For example, after starting the agitator in the reactor and waiting for the actual temperature and pressure to stabilize, the initiator solution is introduced into the reactor at a rate of 2 mL / min using a constant flow pump. At this point, the perfluoropolyether monomer and the ionic liquid monomer begin a random copolymerization reaction. After the reaction begins, the pressure reading inside the reactor is continuously observed. Once a pressure drop is observed, the rate at which the initiator solution is introduced is reduced to 1 mL / min. The total amount of initiator added to the initiator solvent is 0.001% to 1% of the total mass of the polymerizing monomers (i.e., perfluoropolyether monomers and ionic liquid monomers), more preferably 0.02% to 0.4%. Therefore, the amount of initiator added is appropriate to ensure the smooth progress of the copolymerization reaction. It should be noted that the amount of initiator solution is determined based on the amounts of perfluoropolyether monomers, ionic liquid monomers, and organic solvents, as well as the reaction relationship.

[0059] According to some embodiments of the present invention, the vacuuming process of the reactor includes: purging the reactor with nitrogen gas for gas replacement, followed by vacuuming, repeating this process three times. When the oxygen content in the reactor is detected to be less than 10 ppm, the vacuuming process is continued. The above-mentioned deoxygenation step is to prevent oxygen from inhibiting the copolymerization reaction, thereby further ensuring the smooth progress of the copolymerization reaction.

[0060] According to some embodiments of the present invention, the organic solvent includes acetonitrile, acetone, dimethyl sulfoxide, N,N-dimethylformamide, 1,3-dimethyl-2-imidazolinone, or hexamethylphosphoramide. And / or, the initiator solution is an initiator dissolved in an organic solvent, and the initiator includes at least one selected from cumene hydroperoxide, azobisisobutyronitrile, azobisisoheptanenitrile, benzoyl peroxide, dialkyl peroxide, diisopropyl percarbonate, di-n-propyl percarbonate, tert-butyl hydroperoxide, and tert-butyl peroxide benzoate. And / or, the precipitant includes methanol, ethanol, or methyl tert-butyl ether.

[0061] The organic solvent used to dissolve the fluorinated polyether monomer can be the same as or different from the organic solvent used to dissolve the ionic liquid monomer. That is, the organic solvents in solutions A and B can be the same or different, and each solution can use one of the aforementioned organic solvents. This facilitates the rapid dissolution of the fluorinated polyether monomer, the ionic liquid monomer, and the initiator, which is beneficial for the preparation of the binder. The initiator can be one of the aforementioned initiators or a mixture of multiple initiators to promote the copolymerization reaction. Furthermore, the precipitant is a common reagent, widely available and easily purchased, reducing the difficulty of binder preparation and improving production efficiency.

[0062] According to some embodiments of the present invention, the filtration and drying of the precipitated product specifically includes: drying the precipitated product in a vacuum oven at 80°C to 100°C for 24 hours. Thus, after drying at the above temperature for 24 hours, the binder is obtained. Preferably, drying at 80°C does not affect the performance of the binder.

[0063] The method for preparing the adhesive according to the second aspect of this application includes the following steps: Step 1: Take the fluorinated polyether monomer F(CF(CF3)CF2O) a CF(CF3)-R CC1 A homogeneous solution of fluorinated polyether monomer (solution A) was prepared by dissolving it in an organic solvent and dispersing it with stirring. The fluorinated polyether monomer contains unsaturated carbon-carbon double bond functional groups.

[0064] Step 2: Dissolve the ionic liquid monomer in an organic solvent, stir and disperse to prepare a homogeneous ionic liquid monomer solution (solution B). The ionic liquid monomer consists of cations and anions with unsaturated carbon-carbon double bonds.

[0065] Step 3: Dissolve the thermal initiator in an organic solvent, stir and disperse to prepare a uniform initiator solution.

[0066] Step 4: Mix the fluorinated polyether monomer solution and the ionic liquid monomer solution obtained in Step 1 and Step 2 to obtain a mixed precursor solution (solution C). In the above mixed precursor solution, the molar ratio of the fluorinated polyether monomer to the ionic liquid monomer is 10:1 to 1:1.

[0067] Step 5: Vacuum the 10L horizontal reactor equipped with a ribbon agitator, then draw in the above-mentioned mixed precursor solution. Further, purge the reactor with nitrogen for gas replacement, then perform vacuuming again. Repeat this process three times until the oxygen content is detected to be less than 10 ppm, then continue vacuuming the reactor.

[0068] To promote full copolymerization of the monomers, the reaction is preferably carried out at a relatively low temperature not exceeding 60°C. To increase the branching degree of the copolymer and enhance the entanglement and bonding ability of the copolymer binder molecular chains, the copolymerization reaction is preferably carried out at a relatively high pressure of not less than 4 MPa. Perfluoropolyether monomers and ionic liquid monomers are introduced in equal proportions until the pressure in the reactor is controlled to rise to above 4 MPa.

[0069] Step 6: Turn on the stirring in the reactor, with the ribbon agitator rotating at 40 rpm to 80 rpm; Step 7: After the temperature and pressure of the reactor stabilize, use a constant flow pump to introduce the initiator solution into the reactor at a rate of 2 mL / min. At this time, the perfluoropolyether monomer and the ionic liquid monomer begin to undergo random copolymerization.

[0070] Step 8: After the reaction begins, continuously observe the pressure readings inside the reactor. Once the pressure drops, reduce the initiator flow rate to 1 mL / min.

[0071] Step 9: While observing the pressure drop, continue to feed perfluoropolyether monomer and ionic liquid monomer in the same monomer feeding ratio, and use the regulating valve to control the pressure in the reactor to maintain the set value, that is, the pressure is maintained at 4~8MPa.

[0072] Step 10: Maintain the above reaction conditions. After the reaction has proceeded for 4-8 hours, stop the initiator solution and stop the monomer feed. Discharge the unreacted monomer into the reactor and reduce the pressure to atmospheric pressure. Then, introduce nitrogen gas for gas replacement.

[0073] Step 11: Quickly introduce cooling brine to rapidly cool the product, thereby quickly terminating the copolymerization reaction and reducing the content of oligomers in the product.

[0074] Step 12: When the temperature drops to room temperature, add a precipitant to the slurry obtained from the copolymerization reaction to carry out a precipitation reaction to obtain a precipitated product.

[0075] Step 13: The precipitated product is filtered and dried to obtain the binder. The drying process is carried out in a vacuum oven at 80℃~100℃ for 24 hours, preferably at 80℃.

[0076] Preferably, the fluorinated polyether ionomer binder has a weight-average molecular weight of over 600,000 and a molecular weight distribution (PD) of less than 2.0.

[0077] The positive electrode slurry according to a third aspect of the present invention includes a binder according to the first aspect of the present invention, or a binder prepared according to the preparation method of the second aspect of the present invention.

[0078] According to the embodiments of the present invention, by using the above-mentioned binder, the loading of active material in the positive electrode slurry is increased, and the performance and conductivity of the positive electrode slurry are also improved.

[0079] For example, the positive electrode slurry also includes a sulfide solid electrolyte and a slurry solvent. The binder described above in this application provides chemical stability to the sulfide solid electrolyte, which includes Li3PS4 and Li7P3S. 11 Li 11 GeP2S 12 Li6PS5Cl, Li7P2S8I, Li 10 SnP2S 12 Li 3 .25 Ge 0 .25 P 0 .75 S4, Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 Li6PS5Br, Li6PS5I, Li7P 2.9 S 10.85 Mo 0.01 Li 10 Si 0.3 Sn 0.7 P2S 12 Li 9.54 Si 1.74 P 1.44 S 11.7 Cl 0.3 Li 6.6 Sb 0.4 Si 0.6 S5I, Li 6.5 Sb 0.5 Ge 0.5 S5I, Li 6.6 P 0.4 Ge 0.6 S5I, Li 5.3 PS 4.3ClBr 0.7 One or a combination of several of them.

[0080] The binder can be dissolved in a slurry solvent stable for sulfide solid electrolytes, such as a nonpolar or low-polarity organic solvent, including at least one of toluene, o-xylene, m-xylene, p-xylene, a mixture of xylene isomers, mesitylene, anisole, methyl benzoate, monochlorobenzene, cyclohexane, cyclohexanone, n-hexane, n-heptane, n-decane, dichloromethane, butyl butyrate, isobutyl isobutyrate, methylformamide, diisopropyl ketone, and diisobutyl ketone. Preferably, when the binder is used in the solid-state battery cathode slurry, it is further vacuum dried at 80°C, resulting in a water content of less than 10 ppm.

[0081] Therefore, the binder of this application can be used in common sulfide solid electrolytes to prepare all-solid-state batteries. It has lower requirements for the precision of the solid electrolyte and slurry solvent, meaning fewer restrictions on materials and wider applicability, which is beneficial for the preparation of the positive electrode slurry and improves its usability and applicability.

[0082] According to a fourth aspect of the present invention, the positive electrode sheet includes the positive electrode slurry according to the third aspect of the present invention.

[0083] According to the embodiments of the present invention, by using the above-mentioned positive electrode slurry, the positive electrode sheet is beneficial to the use and performance of the positive electrode sheet, and the positive electrode sheet also has good conductivity.

[0084] A battery according to a fifth aspect embodiment of the present invention includes a positive electrode slurry according to the third aspect embodiment described above, or a positive electrode sheet according to the fourth aspect embodiment described above.

[0085] According to the embodiments of the present invention, the battery can be an all-solid-state battery. By using the above-mentioned positive electrode slurry or positive electrode sheet, the energy density and capacity of the battery are improved, which is beneficial to the long-term use of the battery.

[0086] An electrical appliance according to a sixth aspect of the present invention includes a battery according to the fifth aspect of the present invention.

[0087] According to embodiments of the present invention, the performance of electrical devices is improved by employing the aforementioned batteries. Examples of such electrical devices include vehicles, aircraft, ships, computers, energy storage cabinets, etc.

[0088] The embodiments of the present invention are described in detail below. It should be noted that the embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. In addition, unless otherwise specified, all reagents used in the following embodiments are commercially available or can be synthesized according to the methods described herein or known to others. For reaction conditions not listed, they are also readily available to those skilled in the art.

[0089] The binder and battery of the present invention will be described through exemplary specific embodiments in conjunction with comparative examples. The following tests will examine the performance of the batteries of Examples 1-9 and Comparative Examples 1-2.

[0090] In this study, the binders prepared using the examples and comparative examples were used to prepare the positive electrode sheet, and all-solid-state batteries were assembled for testing of ionic conductivity and battery performance.

[0091] In preparing the adhesive solution, cyclohexane, xylene, anisole, or butyl butyrate can be selected as adhesive solutions for solubility experiments.

[0092] The testing methods are as follows: The ionic conductivity of the positive electrode was tested using an electrochemical workstation. Five batteries from each of Example 1 and Comparative Example 1 were taken, and the average ionic conductivity was recorded as I1. The battery performance of the positive electrode in the all-solid-state battery was tested using a LAND CT 2001C secondary battery performance testing device. Five batteries from each of Example 1 and Comparative Example 1 were taken, and the batteries were subjected to charge-discharge cycle tests at a rate of 0.1C. The average initial specific capacity of the active positive electrode at a rate of 0.1C was recorded as Q1. During the cycle, when the battery capacity was lower than 80% of the initial discharge capacity, the cycle was terminated, and the number of cycles was the cycle life of the battery. The average battery cycle life at a rate of 0.1C was recorded as L1. Five batteries from each of Example 1 and Comparative Example 1 were taken, and the batteries were subjected to rate performance tests at rates of 0.1C, 0.2C, 0.33C, 0.5C, and 1.0C, and the average charge specific capacity of the battery at different rates was recorded as Q2-Q6.

[0093] Example 1 In solid-state batteries, the positive electrode comprises a positive electrode active material, a sulfide solid electrolyte, a conductive agent, a binder, and a current collector. The positive electrode active material, sulfide solid electrolyte, conductive agent, and binder form a layered structure on the surface of the current collector. The sulfide solid electrolyte, conductive agent, and binder are uniformly dispersed between the positive electrode active materials and are linked together by the binder.

[0094] The specific preparation process of the adhesive includes the following steps: (1) Take the fluorinated polyether monomer F(CF(CF3)CF2O)a CF(CF3)-(CH2)3CH=CH2 was dissolved in dimethyl sulfoxide solvent and dispersed by heating and stirring at 60°C for 4 hours to prepare a homogeneous fluorinated polyether monomer solution. The mass fraction of the fluorinated polyether monomer was 10 wt%. (2) The ionic liquid monomer (1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide salt) was dissolved in dimethyl sulfoxide solvent and stirred at room temperature for 30 min to prepare a homogeneous ionic liquid monomer solution. The mass fraction of the ionic liquid monomer was 10 wt%. (3) Dissolve the azobisisobutyronitrile initiator in dimethyl sulfoxide solvent, stir at room temperature for 30 min, and disperse to prepare a uniform initiator solution. The mass fraction of azobisisobutyronitrile is 0.1 wt%. (4) The prepared fluorinated polyether monomer solution and ionic liquid monomer solution are mixed in a ratio of 10:1 to obtain a mixed precursor solution.

[0095] (5) Vacuum treatment is performed on the 10L horizontal reactor, and then the above mixed precursor solution is drawn in, with the volume of the drawn solution being 35% of the container volume. Nitrogen gas is then introduced into the reactor for gas replacement, and then vacuum treatment is performed. This operation is repeated three times until the oxygen content is detected to be lower than 10 ppm, and then the reactor is vacuumed again.

[0096] (6) Turn on the stirring function of the reactor and set the speed of the ribbon agitator to 60 rpm. Turn on the reactor heating and set the reaction temperature to 40℃. Introduce the mixed monomers into the reactor at a ratio of 10:1 for the molar number of perfluoropolyether monomers and ionic liquid monomers until the reactor pressure is controlled to rise to 8 MPa.

[0097] (7) Wait for the temperature and pressure of the reactor to stabilize. Use a constant flow pump to introduce the initiator solution into the reactor at a rate of 2 ml / min. Continuously observe the pressure reading changes in the reactor. After observing the pressure drop, reduce the initiator introduction rate to 1 ml / min. At the same time, continue to introduce the mixed monomers according to the same feed ratio and maintain the pressure in the reactor at 8 MPa. Continue the copolymerization reaction for 4 h.

[0098] (8) Stop the introduction of the initiator solution and mixed monomers, reduce the gas pressure, and introduce nitrogen for gas replacement. Then, quickly introduce cooling brine to cool down. When the temperature drops to room temperature, add ethanol precipitant to the copolymer slurry, filter the precipitated binder product, and place the filtered product in an 80 °C vacuum drying oven for 24 h drying. The binder of the first aspect embodiment of this application is thus obtained.

[0099] Preparation of the positive electrode slurry: The slurry raw materials are obtained by mass percentage as follows: 15% sulfide solid electrolyte, 0.5% conductive agent, 1.25% binder, and the remaining ternary positive electrode active material. The ternary positive electrode active material is NCM811 single crystal with a particle size D. 50 =4 μm. The sulfide solid electrolyte is Li6PS5Cl electrolyte with an ionic conductivity of 5 mS / cm and a particle size of 1 μm; the conductive agent is Super P with a particle size of 20 nm. The positive electrode active material, sulfide solid electrolyte, and binder are sequentially added to anisole solvent and stirred thoroughly at 25 °C for 2 h at a stirring speed of 4000 rpm and a dispersion rate of 1500 rpm. The water content of the anisole solvent is less than 10 ppm. Subsequently, the conductive agent is added and stirred for another 2 h to obtain a viscosity of 12000-16000 mPa·s. -1 The positive electrode slurry has a solid content of 70 wt%.

[0100] Positive electrode preparation: The positive electrode slurry is uniformly coated on the surface of the carbon-coated aluminum foil current collector by transfer coating. It is then dried by forced air drying at 80 °C for 1 h, and further dried under vacuum at 80 °C for 1 h to remove residual solvent and moisture from the positive electrode, thus obtaining the positive electrode.

[0101] All-solid-state battery assembly: The obtained binder-containing positive electrode sheet is stacked with a solid electrolyte sheet and a negative electrode sheet, the tabs are welded, and the assembly is sealed to form a battery cell. The resulting solid-state battery cell is first subjected to preheating and pressing treatment, followed by isostatic pressing treatment, to obtain an all-solid-state battery containing binder. The temperature of the preheating and pressing treatment is 80 ℃, and the pressure of the preheating and pressing treatment is 20 MPa; the pressure of the isostatic pressing treatment is 500 MPa.

[0102] Example 2 The main difference from Example 1 is that the molar ratio of the perfluoropolyether monomer to the ionic liquid monomer is 8:1.

[0103] Example 3 The main difference from Example 1 is that the molar ratio of the perfluoropolyether monomer to the ionic liquid monomer is 6:1.

[0104] Example 4 The main difference from Example 1 is that the molar ratio of the perfluoropolyether monomer to the ionic liquid monomer is 4:1.

[0105] Example 5 The main difference from Example 1 is that the molar ratio of the perfluoropolyether monomer to the ionic liquid monomer is 2:1.

[0106] Example 6 The main difference from Example 1 is that the molar ratio of the perfluoropolyether monomer to the ionic liquid monomer is 1:1.

[0107] Example 7 The main difference from Example 1 is that the molar ratio of the perfluoropolyether monomer to the ionic liquid monomer is 12:1.

[0108] Example 8 The main difference from Example 1 is that the molar ratio of the perfluoropolyether monomer to the ionic liquid monomer is 0.7:1.

[0109] Comparative Example 1 The adhesive contains no polyionic liquid structural units.

[0110] Comparative Example 2 The adhesive contains no fluorinated polyether structural units.

[0111] The adhesives from the above examples and comparative examples were subjected to solvent solubility tests. The test method was as follows: the adhesives from Examples 1-8 and Comparative Examples 1-2 were dissolved in cyclohexane, xylene, anisole, and butyl butyrate until the adhesive solution changed from a clear and transparent state to a cloudy and foggy state. The maximum mass fraction T of the adhesive solution that could achieve a clear and transparent state was recorded. If there were granular or lumpy aggregates, they were also considered as undissolved. The test results are shown in Table 1.

[0112] The electrochemical performance test results of the batteries in the examples and comparative examples are shown in Table 2.

[0113] Table 1. Solubility test results of the adhesives in the examples and comparative examples.

[0114] The binders obtained in Examples 1-7 can all be dissolved in solvents such as cyclohexane, xylene, anisole, and butyl butyrate to prepare binder solutions, suitable for wet slurry preparation processes in the design of sulfide solid electrolyte composite positive electrodes, composite negative electrodes, and electrolyte sheets. Solubility test results from Examples 1-8 in different solvents show that when the proportion of fluorinated polyether structural units in the fluorinated polyether ionomer binder increases, the increased molecular polarizability of the binder due to the perfluoropolyether segments results in better lipid solubility in non-polar or low-polar solvents, promoting the dissolution of the binder in these solvents. Simultaneously, it can be observed that when the molar ratio between fluorinated polyether structural units and ionic liquid structural units decreases to 4:1, further reducing the proportion of fluorinated polyether structural units in the binder molecule has little effect on solubility. Referring to Table 2, although Example 7 exhibits better solubility, its electrochemical performance is lower than that of Example 6.

[0115] Table 2 Electrochemical performance test results of the batteries in the examples and comparative examples

[0116] Example 6 is a sample prepared using a fluorinated polyether ionomer binder with a molar ratio of fluorinated polyether structural units to ionic liquid structural units of 1:1. The ionic conductivity test results show that the positive electrode of Example 6 has an ionic conductivity of 2.93 × 10⁻⁶. -3 S×cm -1 The ionic conductivity is significantly higher than that of the positive electrode in Comparative Example 1 (2.17 × 10⁻⁶). -3 S×cm -1 The aforementioned performance optimization mainly stems from the ionic liquid structural units contained in the ionomer binder, which endow the binder with certain ionic conductivity characteristics. Compared with the positive electrode sheet made of pure fluorinated polyether binder, which is a non-ionic conductor, the ionic conductivity of the positive electrode sheet made of the binder is effectively improved.

[0117] Cycling tests at 0.1 C rate for the all-solid-state battery revealed that, compared to the binder-assembled all-solid-state battery in Comparative Example 1, the initial discharge specific capacity (199.8 mAh × g) was significantly higher. -1 The all-solid-state batteries assembled with binders in Examples 6 and 7 exhibit a larger initial charge specific capacity, reaching 208.4 mAh × g. -1 The increased capacity comes from the ionic liquid structural units in the binder, which possess ionic conductivity. These units effectively reduce the polarization of the solid-state battery, facilitating the hexagonal-to-hexagonal (H2-H3) phase transition of the active material. Simultaneously, the enhanced bonding performance of the fluorinated polyether ionomer binder helps ensure the structural stability of the cathode's internal structure during long-term cycling, thus significantly improving cycle life. Comparing the charge specific capacity of the all-solid-state batteries used in Example 6 and Comparative Example 1 at rates of 0.1C, 0.2C, 0.33C, 0.5C, and 1.0C, it can be seen that the all-solid-state battery assembled using the fluorinated polyether ionomer binder exhibits better rate performance. This improvement mainly stems from the ionic liquid structural units in the binder, whose ionic conductivity enhances the ion diffusion kinetics of the composite cathode, resulting in minimal electrode polarization and excellent rate performance even at higher current rates.

[0118] Other configurations and operations of the positive electrode slurry, positive electrode sheet, battery, and electrical device according to embodiments of the present invention are known to those skilled in the art and will not be described in detail here.

[0119] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0120] In the description of this invention, "a plurality of" means two or more.

[0121] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0122] Although embodiments of the invention have been shown and described, those skilled in the art will understand 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 claims and their equivalents.

Claims

1. An adhesive, characterized in that, It includes fluorinated polyether ionomers, which are copolymers of fluorinated polyether structural units and polyionic liquid structural units, wherein the fluorinated polyether structural units include fluorinated polyether monomers having unsaturated carbon-carbon double bonds.

2. The adhesive according to claim 1, characterized in that, The molar ratio of the fluorinated polyether structural unit to the polyionic liquid structural unit is 10:1 to 1:

1.

3. The adhesive according to claim 1, characterized in that, The fluorinated polyether monomer is a perfluoropolyether monomer.

4. The adhesive according to any one of claims 1-3, characterized in that, The fluorinated polyether structural unit copolymer premonomer includes a compound having the general chemical formula (1): Equation (1), In equation (1), a = 1 - 16, R CC1 The number of carbon atoms ranges from 1 to 6.

5. The adhesive according to claim 4, characterized in that, The premonomer of the polyionic liquid structural unit copolymer includes a compound having the general chemical formula (2): Equation (2), In equation (2), [X + [Y] is a cation with a carbon-carbon double bond. - The cation is an anion, and the cation includes compounds having the general chemical formula (a)-(g): Formula (a)-(g), (a)-(g) represent pyridyl cation, piperidinyl cation, pyrroloyl cation, pyrrolidone cation, imidazole cation, quaternary phosphonium cation, and quaternary ammonium cation, respectively, R CC2 The number of carbon atoms is 1-6, R CH1 R CH2 R CH3 The number of carbon atoms is independently selected from 1 to 6; The anion is selected from tetrafluorophosphate, bis(trifluoromethanesulfonyl)imide, hexafluorophosphate, bis(fluorosulfonyl)imide, perchlorate, tetrafluoroborate, bis(oxalate-borate), difluorooxalate-borate, or hexafluoroarsenate.

6. The adhesive according to claim 5, characterized in that, The molar ratio of the copolymerization precursor of the fluorinated polyether structural unit to the copolymerization precursor of the polyionic liquid structural unit is 10:1 to 1:

1.

7. A method for preparing an adhesive according to any one of claims 1-6, characterized in that, Includes the following steps: Solution A is obtained by dissolving a fluorinated polyether monomer in an organic solvent; Solution B is obtained by dissolving the ionic liquid monomer in an organic solvent; Solution B is mixed with solution A to obtain solution C; The reaction vessel was evacuated, and then the solution C was drawn in. The initiator solution is introduced into the reactor, and after reacting at a preset temperature and pressure for a preset time, cooling brine is introduced to terminate the copolymerization reaction. A precipitant is added to the slurry obtained by copolymerization to carry out a precipitation reaction and obtain a precipitated product. The precipitated product is filtered and dried to obtain the binder according to any one of claims 1-6.

8. The method for preparing the adhesive according to claim 7, characterized in that, The preset reaction time at preset temperature and preset pressure also includes: When the actual pressure inside the reactor decreases, the fluorinated polyether monomer and the ionic liquid monomer are added to the reactor, and the pressure inside the reactor is adjusted to maintain the preset pressure. The percentage of the sum of the mass of the fluorinated polyether monomer and the ionic liquid monomer to the mass of the organic solvent is ω, wherein ω satisfies: 10%≤ω≤30%.

9. The method for preparing the adhesive according to claim 7, characterized in that, The preset temperature is T, the preset pressure is P, and the preset time is t, wherein T, P, and t respectively satisfy: 20℃≤T≤60℃, 4MPa≤P≤8MPa, and 4h≤t≤8h.

10. The method for preparing the adhesive according to claim 7, characterized in that, The step of introducing the initiator solution into the reaction vessel includes: The initiator solution is introduced into the reaction vessel at a rate of 2 mL / min using a constant flow pump. When the actual pressure inside the reaction vessel decreases, the initiator solution is introduced into the reaction vessel at a rate of 1 mL / min.

11. The method for preparing the adhesive according to claim 7, characterized in that, The total amount of initiator added to the initiator solvent is 0.001% to 1% of the sum of the mass of the fluorinated polyether monomer and the ionic liquid monomer.

12. The method for preparing the adhesive according to claim 7, characterized in that, The process of evacuating the reaction vessel includes: After nitrogen is introduced into the reactor for gas replacement, the vacuuming process is performed. This process is repeated three times. When the oxygen content in the reactor is detected to be less than 10 ppm, the vacuuming process is continued.

13. The method for preparing the adhesive according to claim 7, characterized in that, The organic solvent includes acetonitrile, acetone, dimethyl sulfoxide, N,N dimethylformamide, 1,3-dimethyl-2-imidazolinone, or hexamethylphosphoramide; and / or, The initiator solution is an initiator dissolved in the organic solvent, and the initiator includes at least one selected from cumene hydroperoxide, azobisisobutyronitrile, azobisisoheptanenitrile, benzoyl peroxide, dialkyl peroxide, diisopropyl percarbonate, di-n-propyl percarbonate, tert-butyl hydroperoxide, and tert-butyl benzoate peroxide; and / or, The precipitant includes methanol, ethanol, or methyl tert-butyl ether.

14. The method for preparing the adhesive according to any one of claims 7-13, characterized in that, The precipitated product is filtered and dried, specifically including: The precipitated product was dried in a vacuum oven at 80℃~100℃ for 24 hours.

15. A positive electrode slurry, characterized in that, The adhesive includes any one of claims 1-6, or the adhesive prepared by any one of claims 7-14.

16. A positive electrode plate, characterized in that, Includes the positive electrode slurry according to claim 15.

17. A battery, characterized in that, This includes the positive electrode slurry according to claim 15, or the positive electrode sheet according to claim 16.

18. An electrical appliance, characterized in that, Includes the battery according to claim 17.

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