Sulfide electrolyte paste, method of preparation and use thereof

Abstract

This invention provides a sulfide electrolyte slurry, its preparation method, and its application. The sulfide electrolyte slurry comprises a solid phase component and an organic solvent. The solid phase component includes a sulfide electrolyte, a binder, and a dispersant. The dispersant is a polyester-type superdispersant, and its weight content in the solid phase component is 0.1-1%. By adding a polyester-type superdispersant to the sulfide electrolyte slurry and controlling the amount added, the viscosity of the sulfide electrolyte slurry can be effectively reduced, the agglomeration phenomenon in the sulfide electrolyte slurry can be improved, and the resulting sulfide electrolyte slurry can be more uniform during coating. The resulting sulfide electrolyte film has better flexibility, which is beneficial for further improving the processing quality and conductivity of the sulfide electrolyte and enhancing the overall electrochemical performance of the battery.

Description

Technical Field

[0001] This invention relates to the field of all-solid-state battery technology, and more specifically, to a sulfide electrolyte slurry, its preparation method, and its application. Background Technology

[0002] Solid-state batteries, as a revolutionary energy storage technology, are widely considered a key development direction for electric vehicles, consumer electronics, and large-scale energy storage systems due to their high energy density, high safety, and long cycle life. Compared to traditional lithium-ion batteries, solid-state batteries abandon liquid or gel electrolytes and instead use solid electrolytes, significantly improving battery safety and operating temperature range. Solid electrolytes mainly include sulfide-type, oxide-type, and polymer-type electrolytes. Among them, sulfide-type solid electrolytes, such as Li2S-P2S5 and Li6PS5Cl, have excellent ionic conductivity (up to 10⁻⁶ Ω·cm). -2 ~10 -3 Scm -1 Its excellent machinability has made it a hot topic in all-solid-state battery research.

[0003] However, the production of sulfide electrolytes faces a major challenge—agglomeration. Nanoscale sulfide electrolyte particles possess excellent ionic conductivity and good machinability; however, due to their large specific surface area and surface energy, they are highly prone to aggregation and agglomeration during the preparation of electrolyte slurries and subsequent coating processes for electrolyte membranes. This leads to uneven dispersion of the components in the electrolyte slurry, affecting not only the final electrolyte membrane's processing quality but also directly impairing the battery's electrochemical performance. Specifically, this manifests as follows: the dried electrode surface may exhibit noticeable graininess or cracks, affecting aesthetics and functionality; localized electron or ion transport pathways within the electrode may be obstructed, increasing internal resistance and reducing interfacial stability and overall efficiency; the electrode may become brittle, easily peeling and cracking, resulting in decreased mechanical properties; during coating, a sudden increase in slurry viscosity increases scraper resistance, potentially causing streaks in the coating and affecting product quality; inconsistent solvent evaporation rates around agglomerates may generate residual stress after drying, affecting the consistency and reliability of battery performance.

[0004] To address the problem of sulfide electrolyte agglomeration, introducing dispersants is an effective method to improve the agglomeration and uneven dispersion of sulfide electrolytes. Common dispersants include nonionic, anionic, and cationic types. However, anionic and cationic dispersants are not suitable for sulfide electrolyte solvent systems. Common nonionic dispersants, such as triethanolamine, tributyl phosphate, and terpineol, contain active hydrogen groups such as hydroxyl, carboxyl, and amino groups, which will react with sulfide electrolytes and are therefore unsuitable for this system. Dispersants without polar functional groups, such as all-carbon chain amphiphilic molecules and aromatic aliphatic amphiphilic molecules, are almost ineffective at dispersion.

[0005] In view of the above problems, how to effectively solve the problem of easy agglomeration of nano-sized sulfide electrolyte particles due to high surface energy during slurrying and coating, and how to reduce the van der Waals forces between sulfide electrolyte particles, thereby reducing the viscosity of the slurry and improving the uniformity and processability of coating, has become an urgent problem to be solved in the development of sulfide all-solid-state batteries. Summary of the Invention

[0006] The main objective of this invention is to provide a sulfide electrolyte slurry, its preparation method, and its application, in order to solve the problems of easy agglomeration of nano-sized sulfide electrolyte particles during homogenization and coating processes due to high surface energy, as well as the problems of high slurry viscosity, poor coating uniformity, and poor processability caused by the presence of van der Waals forces in the solid phase components. The aim is to further improve the processing quality and electrochemical performance of the sulfide electrolyte slurry and enhance the overall advantages of the battery.

[0007] To achieve the above objectives, according to one aspect of the present invention, a sulfide electrolyte slurry is provided, the sulfide electrolyte slurry comprising a solid phase component and an organic solvent, the solid phase component comprising: a sulfide electrolyte, a binder, and a dispersant; wherein the dispersant is a polyester-type superdispersant, and the weight content of the polyester-type superdispersant in the solid phase component is 0.1-1%.

[0008] Furthermore, the weight content of the polyester-type superdispersant in the solid phase is 0.2~0.5%;

[0009] Furthermore, the polyester-type superdispersant is selected from at least one of Solsperse-3000, Solsperse-11000, Solsperse-11200, Solsperse-13300, Solsperse-13400, Solsperse-13940, Solsperse-16000, Solsperse-17000, Solsperse-17940 and Solsperse-21000.

[0010] Furthermore, the polyester-type superdispersant is selected from at least one of Solsperse-3000, Solsperse-17000 and Solsperse-21000.

[0011] Furthermore, the polyester-type superdispersant is selected from Solsperse-3000 and / or Solsperse-21000.

[0012] Furthermore, when the polyester-type superdispersant is at least one of Solsperse-3000, Solsperse-11000 or Solsperse-11200, the weight content of the dispersant in the solid phase is 0.1-1%.

[0013] Furthermore, when the polyester-type superdispersant is at least one of Solsperse-13300, Solsperse-13400, Solsperse-13940, Solsperse-16000, Solsperse-17000, Solsperse-17940, and Solsperse-21000, the weight content of the dispersant in the solid phase is 0.1% to 0.5%.

[0014] Furthermore, the weight content of sulfide electrolyte in the solid phase is 95-99%.

[0015] Furthermore, the binder content in the solid phase is 1-5% by weight.

[0016] Furthermore, the D50 particle size range of the sulfide electrolyte is 50 nm to 5 μm.

[0017] Furthermore, the sulfide electrolyte is selected from at least one of LiPSCl, LiGePSCl, LiSnPSCl, LiSbPSClBr, LiSPClIO, LiGePSClBr, and LiGePSClI.

[0018] Furthermore, the adhesive is selected from at least one of polyvinylidene fluoride, styrene-butadiene copolymer, styrene-ethylene-butene copolymer, hydrogenated butadiene-nitrile, polyisoprene, polybutadiene, and vinylidene fluoride-hexafluoropropylene copolymer.

[0019] Furthermore, the organic solvent is selected from at least one of toluene, xylene, isobutyl isobutyrate, cyclohexane, diethyl ether, ethyl acetate, and white oil.

[0020] According to a second aspect of the present invention, a method for preparing a sulfide electrolyte slurry is provided, comprising the following steps: mixing a sulfide electrolyte and a polyester-type superdispersant in an organic solvent to obtain a first mixed slurry; subjecting the first mixed slurry to a first ball milling to obtain a second mixed slurry; adding a binder to the second mixed slurry to obtain a third mixed slurry; and subjecting the third mixed slurry to a second ball milling to obtain a sulfide electrolyte slurry.

[0021] Furthermore, the first and second ball milling processes are carried out under a protective gas atmosphere.

[0022] Furthermore, the protective gas is selected from one or more of argon, nitrogen, or helium.

[0023] Furthermore, the first ball milling time is 0.5~2h, and the first ball milling speed is 200~400r / min.

[0024] Furthermore, the second ball milling time is 0.5~2h, and the rotation speed of the second ball mill is 200~400r / min.

[0025] According to a third aspect of the present invention, an application of a sulfide electrolyte slurry is provided, wherein the sulfide electrolyte slurry is used to prepare at least one of a positive electrode, a negative electrode, or an electrolyte layer.

[0026] Applying the technical solution of this invention, a sulfide electrolyte slurry is provided. This sulfide electrolyte slurry comprises a solid phase component and an organic solvent. The solid phase component includes a sulfide electrolyte, a binder, and a dispersant. The dispersant is a polyester-type superdispersant, and its weight content in the solid phase component is 0.1-1%. By adding a polyester-type superdispersant and controlling its amount, the viscosity of the sulfide electrolyte slurry can be effectively reduced, and the agglomeration phenomenon in the sulfide electrolyte slurry can be improved. This results in a more uniform sulfide electrolyte slurry during coating, and the resulting sulfide electrolyte film has better flexibility. This, in turn, helps to further improve the processing quality and conductivity of the sulfide electrolyte, and enhances the overall electrochemical performance of the battery. Detailed Implementation

[0027] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the embodiments.

[0028] As described in the background section, nanoscale sulfide electrolyte particles possess excellent ionic conductivity and good machinability. However, due to their large specific surface area and surface energy, they are prone to aggregation and agglomeration during the preparation of electrolyte slurries and subsequent coating processes for electrolyte membranes. This leads to uneven dispersion of the various components in the electrolyte slurry, affecting not only the final electrolyte membrane processing quality but also directly damaging the electrochemical performance of the battery. Currently, introducing dispersants during electrolyte slurry preparation is one of the effective methods to improve the agglomeration and uneven dispersion of sulfide electrolytes. However, existing common dispersants, such as nonionic, anionic, and cationic dispersants, are insufficient to meet the practical application requirements for improving the agglomeration of solid components.

[0029] To address the aforementioned problems, in a first typical embodiment of this application, a sulfide electrolyte slurry is provided. This sulfide electrolyte slurry comprises a solid phase component and an organic solvent. The solid phase component includes a sulfide electrolyte, a binder, and a dispersant. The dispersant is a polyester-type superdispersant, and its weight content in the solid phase component is 0.1-1%. By adding a polyester-type superdispersant and controlling its amount, the viscosity of the sulfide electrolyte slurry provided in this application can be effectively reduced, and the agglomeration phenomenon in the sulfide electrolyte slurry can be improved. This results in a more uniform sulfide electrolyte slurry during coating, and the resulting sulfide electrolyte film exhibits better flexibility. This, in turn, helps to further improve the processing quality and conductivity of the sulfide electrolyte, thereby enhancing the overall electrochemical performance of the battery.

[0030] First, nano- or micro-sized sulfide electrolyte particles have high surface energy due to their large specific surface area. When these electrolyte particles approach each other, the high surface energy causes them to attract each other through van der Waals forces and other forces, leading to aggregation and affecting the uniform dispersion and overall performance of the sulfide electrolyte. The polyester-type superdispersant (such as Solsperse-3000) described in this application contains a small amount of active hydrogen at its end groups, which can act as active sites to anchor the surface of the sulfide electrolyte particles. This anchoring effect, dominated by chemical bonds, is stronger and can reduce the desorption of the dispersant during shear mixing of the slurry, allowing the sulfide electrolyte particles in the electrolyte slurry to be better dispersed. In addition, the polyester-type superdispersant has a long alkane side chain, which makes the reactivity of the active hydrogen at the end groups of the dispersant weaker, resulting in good compatibility with the sulfide electrolyte particles without causing destructive chemical reactions. Furthermore, the adsorption of polyester-type superdispersants on the surface of sulfide particles can significantly reduce the surface energy of sulfide electrolyte particles, weaken the attraction between sulfide electrolyte particles, and thus effectively inhibit the aggregation of sulfide electrolytes. The reduction in surface energy and the inhibition of aggregation are beneficial to improving the leveling properties of the sulfide electrolyte slurry during the coating process, enabling it to form a more uniform and particle-free coating layer on the electrode, and also giving the resulting sulfide electrolyte membrane better uniformity and flexibility.

[0031] Secondly, polyester-type superdispersants are dispersants with long-chain structures, which play a "steric hindrance effect" in dispersion. When the dispersant adsorbs onto the surface of sulfide particles, its extended long-chain molecular ends act as a "barrier" between sulfide electrolyte particles, preventing aggregation caused by close proximity between the particles. This reduces particle settling and viscosity increase during the electrolyte slurry's settling process, better maintaining the slurry's stability. Furthermore, the physical isolation effect of the dispersant's long chains reduces the collision frequency between sulfide electrolyte particles in the slurry, further reducing viscosity increase due to agglomeration. Lower slurry viscosity is beneficial for increasing the content of electrolyte solid particles in the slurry, meaning more electrode material can exist in the same volume of slurry, reducing solvent usage. This is highly advantageous for energy consumption and cost control during the drying process. Moreover, the use of high-solids slurries can reduce binder floating, preventing increased porosity within the electrode sheet, ultimately improving the mechanical strength and stability of the battery electrode.

[0032] In addition to the aforementioned effects, polyester-based superdispersants can also form a protective film on the surface of sulfide electrolyte particles. This film reduces the direct contact between sulfides and moisture and oxygen in the environment, improving the air stability of the sulfide electrolyte. Sulfide electrolytes are particularly sensitive to the presence of humidity and oxygen, and are prone to chemical reactions leading to performance degradation. Polyester-based superdispersants can isolate these potential corrosive factors, especially during preparation and processing, providing a more stable environment for sulfide electrolytes, extending their service life in air, simplifying the operation process, reducing the requirements for dust-free and inert gas environments, and facilitating the large-scale production and application of all-solid-state batteries.

[0033] In summary, by adding a polyester-type superdispersant and controlling the amount of polyester-type superdispersant added, the viscosity of the sulfide electrolyte slurry provided in this application can be effectively reduced, the agglomeration phenomenon in the sulfide electrolyte slurry can be improved, the resulting sulfide electrolyte slurry is more uniform during the coating process, and the resulting sulfide electrolyte film has better flexibility. This is beneficial to further improve the processing quality and conductivity of the sulfide electrolyte and enhance the overall electrochemical performance of the battery.

[0034] Typical, but not limiting, the sulfide electrolyte slurry provided in this application contains, in the solid phase, a polyester-type superdispersant by weight of 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, or any combination of two values.

[0035] In a preferred embodiment, the weight content of the polyester-type superdispersant in the solid phase component is 0.2-0.5%. As described above, the addition of the polyester-type superdispersant to the sulfide electrolyte slurry can reduce the surface energy of the sulfide electrolyte, improve agglomeration in the sulfide electrolyte slurry, reduce the viscosity of the sulfide electrolyte slurry, and give the sulfide electrolyte slurry better coating uniformity and processability. Controlling the weight content of the dispersant in the sulfide electrolyte slurry within the above-mentioned range can better exert the above-mentioned effects, and can also further improve the conductivity of the sulfide electrolyte slurry, so that the resulting sulfide electrolyte has a better effect. Preferably, the polyester-type superdispersant is selected from at least one of Solsperse-3000, Solsperse-11000, Solsperse-11200, Solsperse-13300, Solsperse-13400, Solsperse-13940, Solsperse-16000, Solsperse-17000, Solsperse-17940, and Solsperse-21000. The aforementioned specific polyester-type superdispersants can better exert their "anchoring effect" and "steric hindrance effect," thereby improving the performance of the sulfide electrolyte slurry. Preferably, the polyester-type superdispersant is selected from at least one of Solsperse-3000, Solsperse-17000, and Solsperse-21000; more preferably, the polyester-type superdispersant is selected from Solsperse-3000 and / or Solsperse-21000. The molecular weight of the aforementioned polyester-type superdispersant allows for better compatibility with sulfide electrolyte particles, thereby improving the performance of the sulfide electrolyte slurry.

[0036] In a preferred embodiment, when the polyester-type superdispersant is at least one of Solsperse-3000, Solsperse-11000, or Solsperse-11200, the weight content of the polyester-type superdispersant in the solid phase is 0.1% to 1%; and / or, when the polyester-type superdispersant is at least one of Solsperse-13300, Solsperse-13400, Solsperse-13940, Solsperse-16000, Solsperse-17000, Solsperse-17940, or Solsperse-21000, the weight content of the polyester-type superdispersant in the solid phase is 0.1% to 0.5%. Different types of polyester-type superdispersants (molecular weight, etc.) will result in different dispersion states and steric hindrance effects in solvents, which in turn will affect the amount added during use. Controlling the addition ratio of the above-mentioned polyester-type superdispersants within the above range can improve the performance of sulfide electrolyte slurry and sulfide electrolyte.

[0037] In a preferred embodiment, the solid phase component contains 95-99% by weight of sulfide electrolyte; and / or, the solid phase component contains 1-5% by weight of binder; preferably, the D50 particle size of the sulfide electrolyte is 50 nm-5 μm. Controlling the weight content of sulfide electrolyte and binder in the electrolyte slurry within the above range can improve the performance of the sulfide electrolyte slurry. This application has a particularly significant effect on nano- and micron-sized sulfide electrolytes.

[0038] In a preferred embodiment, the sulfide electrolyte is selected from one or more of LiPSCl, LiGePSCl, LiSnPSCl, LiSbPSClBr, LiSPClIO, LiGePSClBr, and LiGePSClI; the performance of the corresponding sulfide electrolyte slurry is better when the above-mentioned specific sulfide electrolytes are used in combination with the dispersant provided in this application.

[0039] In a preferred embodiment, the binder is selected from one or more of polyvinylidene fluoride, styrene-butadiene copolymer, styrene-ethylene-butene copolymer, hydrogenated butadiene-nitrile, polyisoprene, polybutadiene, and vinylidene fluoride-hexafluoropropylene copolymer; and / or, the organic solvent is selected from one or more of toluene, xylene, isobutyl isobutyrate, cyclohexane, diethyl ether, ethyl acetate, and white oil. The above-mentioned binder and organic solvent are more effective in improving the performance of sulfide electrolyte slurries.

[0040] In a second typical embodiment of this application, a method for preparing the above-mentioned sulfide electrolyte slurry is provided. The method includes the following steps: mixing sulfide electrolyte and dispersant in an organic solvent to obtain a first mixed slurry; performing a first ball milling on the first mixed slurry to obtain a second mixed slurry; adding a binder to the second mixed slurry to obtain a third mixed slurry; and performing a second ball milling on the third mixed slurry to obtain the sulfide electrolyte slurry. In the preparation process of the above-mentioned sulfide electrolyte slurry, the sulfide electrolyte and dispersant are first mixed and ball-milled, which can fully utilize the anchoring and steric hindrance effects of the dispersant on the sulfide electrolyte particles, making the system more uniformly dispersed. Furthermore, the preferential addition of the dispersant can reduce the competitive adsorption effect of the subsequently added binder on the sulfide electrolyte particles, reducing particle agglomeration, thereby resulting in better dispersion of the various components in the prepared sulfide electrolyte slurry.

[0041] In a preferred embodiment, the first and second ball milling are performed under a protective gas atmosphere; preferably, the protective gas is selected from one or more of argon, nitrogen, or helium; preferably, the first ball milling time is 0.5 to 2 hours, and the first ball milling speed is 200 to 400 r / min; and / or, the second ball milling time is 0.5 to 2 hours, and the second ball milling speed is 200 to 400 r / min. Performing the ball milling process under a protective gas atmosphere can prevent the oxidation of the sulfide electrolyte. Controlling the ball milling time and speed within the above ranges can make the various components in the sulfide electrolyte more uniformly dispersed.

[0042] In a third typical embodiment of this application, an application of the above-mentioned sulfide electrolyte slurry is provided, in which the sulfide electrolyte slurry is used to prepare at least one of a positive electrode, a negative electrode, or an electrolyte layer. Using the sulfide electrolyte slurry provided in this application to prepare the positive electrode, negative electrode, and electrolyte layer can effectively improve the agglomeration phenomenon in the sulfide electrolyte slurry, which is beneficial to further improving the overall electrochemical performance of the prepared battery.

[0043] The present application will be further described in detail below with reference to specific embodiments, which should not be construed as limiting the scope of protection claimed in the present application.

[0044] Example 1

[0045] (1) Dissolve 1g of Solsperse-3000 in 10g of isobutyl isobutyrate solvent to form a 10wt% dispersant solution for later use; in a glove box filled with nitrogen, add 9.7g of sulfide electrolyte powder (LiPSCl, D50: 300 nm), 0.5g of dispersant solution (10wt%) and 7.73g of isobutyl isobutyrate solvent to a quartz ball mill jar, and ball mill at 300r / min for 30min under nitrogen atmosphere to mix evenly.

[0046] (2) Dissolve 1g of PVDF binder in 10g of isobutyl isobutyrate to form a 10wt% binder solution for later use; then add the above 3.0g binder solution (10wt%) under nitrogen atmosphere, and continue ball milling at 300r / min for 55min to obtain a uniformly dispersed sulfide electrolyte slurry.

[0047] The dispersant component was added at 0.5 wt% of the solid component in the resulting electrolyte slurry, and the binder component was added at 3 wt% of the solid component in the resulting electrolyte slurry. Subsequently, under a nitrogen atmosphere, the above-mentioned sulfide electrolyte slurry was coated onto PET, and after being air-dried in a glove box, it was transferred to an oven for further drying to obtain an electrolyte film with a thickness of approximately 120 μm.

[0048] Example 2

[0049] The difference between Example 2 and Example 1 is that the amount of dispersant Solsperse-3000 added is 0.1 wt% of the weight of the solid phase component in the resulting electrolyte slurry.

[0050] Example 3

[0051] The difference between Example 3 and Example 1 is that the amount of dispersant Solsperse-3000 added is 1 wt% of the weight of the solid phase component in the resulting electrolyte slurry.

[0052] Example 4

[0053] The difference between Example 4 and Example 1 is that the amount of dispersant Solsperse-3000 added is 0.2 wt% of the weight of the solid phase component in the resulting electrolyte slurry.

[0054] Example 5

[0055] The difference between Example 5 and Example 1 is that the dispersant used is Solsperse-11000.

[0056] Example 6

[0057] The difference between Example 6 and Example 1 is that the dispersant used is Solsperse-11200.

[0058] Example 7

[0059] The difference between Example 7 and Example 1 is that the dispersant used is Solsperse-13400.

[0060] Example 8

[0061] The difference between Example 8 and Example 1 is that the dispersant used is Solsperse-13940.

[0062] Example 9

[0063] The difference between Example 9 and Example 1 is that the dispersant used is Solsperse-17000.

[0064] Example 10

[0065] The difference between Example 10 and Example 1 is that the dispersant used is Solsperse-21000.

[0066] Example 11

[0067] The difference between Example 11 and Example 1 is that the dispersant used is Solsperse-21000, and the amount of dispersant added is 0.8% of the weight of the solid phase component in the resulting electrolyte slurry.

[0068] Example 12

[0069] The difference between Example 12 and Example 1 is that the sulfide electrolyte used in the electrolyte slurry is LiGePSCl, and the amount of sulfide electrolyte added is 9.5g, while the amount of binder polyvinylidene fluoride (PVDF) added is 0.5g.

[0070] Example 13

[0071] The difference between Example 13 and Example 1 is that the sulfide electrolyte used in the electrolyte slurry is LiPSCl, and the amount of sulfide electrolyte added is 9.9g, while the amount of binder polyvinylidene fluoride (PVDF) added is 0.1g.

[0072] Comparative Example 1

[0073] The difference between Comparative Example 1 and Example 1 is that no dispersant was added to the sulfide electrolyte slurry.

[0074] Comparative Example 2

[0075] The difference between Comparative Example 2 and Example 1 is that the amount of dispersant Solsperse-3000 added is 2% of the weight of the solid phase component in the resulting electrolyte slurry.

[0076] Comparative Example 3

[0077] The difference between Comparative Example 3 and Example 1 is that the dispersant added to the sulfide electrolyte slurry is an organosilicon-based superdispersant BYK-190.

[0078] Comparative Example 4

[0079] The difference between Comparative Example 4 and Example 1 is that the dispersant and binder are added in the following order: the binder solution is added first and ball-milled, followed by the dispersant solution.

[0080] The sulfide electrolyte slurries prepared in the above embodiments and comparative examples were tested for relevant properties, and the results are shown in Table 1. Regarding the test results in Table 1, the following further explanation is needed:

[0081] Performance testing: The tensile strength of the obtained electrolyte membrane was measured by a tensile testing machine, which reflects the uniformity and integrity of the prepared electrolyte membrane; the viscosity of the obtained sulfide electrolyte slurry was tested by a rotational rheometer; and the ionic conductivity of the obtained electrolyte membrane was tested by an electrochemical workstation.

[0082] Table 1

[0083]

[0084] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects:

[0085] The sulfide electrolyte slurry provided by this invention includes a solid phase component and an organic solvent. The solid phase component includes a sulfide electrolyte, a binder, and a dispersant. The dispersant is a polyester-type superdispersant, and its weight content in the solid phase component is 0.1-1%. By adding a polyester-type superdispersant and controlling its amount, the viscosity of the sulfide electrolyte slurry can be effectively reduced, and the agglomeration phenomenon in the sulfide electrolyte slurry can be improved. This results in a more uniform sulfide electrolyte slurry during coating, and the resulting sulfide electrolyte film has better flexibility. This, in turn, helps to further improve the processing quality and conductivity of the sulfide electrolyte, and enhances the overall electrochemical performance of the battery.

[0086] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A sulfide electrolyte slurry, characterized in that, The sulfide electrolyte slurry comprises a solid phase component and an organic solvent, wherein the solid phase component comprises: a sulfide electrolyte, a binder, and a dispersant; The dispersant is a polyester-type superdispersant, and the weight content of the polyester-type superdispersant in the solid phase component is 0.1-1%.

2. The sulfide electrolyte slurry according to claim 1, characterized in that, In the solid phase component, the weight content of the polyester-type superdispersant is 0.2~0.5%; Preferably, the polyester-type superdispersant is selected from at least one of Solsperse-3000, Solsperse-11000, Solsperse-11200, Solsperse-13300, Solsperse-13400, Solsperse-13940, Solsperse-16000, Solsperse-17000, Solsperse-17940, and Solsperse-21000; Preferably, the polyester-type superdispersant is selected from at least one of Solsperse-3000, Solsperse-17000, and Solsperse-21000; More preferably, the polyester-type superdispersant is selected from Solsperse-3000 and / or Solsperse-21000.

3. The sulfide electrolyte slurry according to claim 2, characterized in that, When the polyester-type superdispersant is at least one of Solsperse-3000, Solsperse-11000, or Solsperse-11200, the weight content of the polyester-type superdispersant in the solid phase component is 0.1% to 1%. And / or, when the polyester-type superdispersant is at least one of Solsperse-13300, Solsperse-13400, Solsperse-13940, Solsperse-16000, Solsperse-17000, Solsperse-17940 or Solsperse-21000, the weight content of the polyester-type superdispersant in the solid phase component is 0.1~0.5%.

4. The sulfide electrolyte slurry according to any one of claims 1 to 3, characterized in that, In the solid phase composition, the weight content of the sulfide electrolyte is 95-99%; And / or, in the solid phase component, the weight content of the binder is 1-5%; Preferably, the D50 particle size of the sulfide electrolyte is 50 nm to 5 μm.

5. The sulfide electrolyte slurry according to any one of claims 1 to 3, characterized in that, The sulfide electrolyte is selected from at least one of LiPSCl, LiGePSCl, LiSnPSCl, LiSbPSClBr, LiSPClIO, LiGePSClBr, and LiGePSClI.

6. The sulfide electrolyte slurry according to any one of claims 1 to 3, characterized in that, The adhesive is selected from at least one of polyvinylidene fluoride, styrene-butadiene copolymer, styrene-ethylene-butene copolymer, hydrogenated butadiene-nitrile, polyisoprene, polybutadiene, and vinylidene fluoride-hexafluoropropylene copolymer; And / or, the organic solvent is selected from at least one of toluene, xylene, isobutyl isobutyrate, cyclohexane, diethyl ether, ethyl acetate, and white oil.

7. A method for preparing a sulfide electrolyte slurry according to any one of claims 1 to 6, characterized in that, The preparation method of the sulfide electrolyte slurry includes the following steps: A sulfide electrolyte and a polyester-type superdispersant are mixed in an organic solvent to obtain a first mixed slurry; the first mixed slurry is then subjected to a first ball milling to obtain a second mixed slurry. A binder is added to the second mixed slurry to obtain a third mixed slurry; the third mixed slurry is then subjected to a second ball milling to obtain the sulfide electrolyte slurry.

8. The method for preparing the sulfide electrolyte slurry according to claim 6, characterized in that, The first ball milling and the second ball milling were carried out under a protective gas atmosphere; Preferably, the protective gas is selected from one or more of argon, nitrogen, or helium.

9. The method for preparing the sulfide electrolyte slurry according to claim 6, characterized in that, The first ball milling time is 0.5~2h, and the rotation speed of the first ball mill is 200~400r / min; And / or, the second ball milling time is 0.5~2h, and the rotation speed of the second ball mill is 200~400r / min.

10. The application of a sulfide electrolyte slurry according to any one of claims 1 to 6, characterized in that, The sulfide electrolyte slurry is used to prepare at least one of the following: a positive electrode, a negative electrode, or an electrolyte layer.

Images