Inorganic oxide solid electrolyte dispersion liquid with stable solids content for batteries, manufacturing processes and applications thereof

Abstract

The present invention discloses an inorganic oxide solid electrolyte dispersion fluid with a stable solids content for batteries, a manufacturing process, and an application thereof. The inorganic oxide solid electrolyte dispersion fluid according to the invention consists of a granular inorganic oxide solid electrolyte and a solvent without additives, wherein the solvent in the dispersion fluid is an aprotic solvent with a polarity of 4 to 8, and the solids content of the dispersion fluid is 40 wt.% to 85 wt.%. In the inorganic oxide solid electrolyte dispersion fluid according to the invention, the particles do not agglomerate when the solids content is within this range, thus achieving high stability and reducing the costs of storage, transport, and use.Due to the higher solids content, the dispersion fluid consumes less solvent, which can effectively reduce the production costs of the dispersion fluid.

Description

[0001] The present invention relates to the technical field of lithium batteries, particularly to an inorganic oxide solid electrolyte dispersion liquid with stable solid content for batteries, a manufacturing method and an application thereof.

[0002] With the continuous increase in battery energy density, safety concerns are becoming increasingly important. The introduction of an inorganic solid electrolyte, especially an inorganic oxide solid electrolyte that can replace a flammable organic electrolyte, into a battery generally involves application in the modification of pole pieces and separators, which can improve the safety performance of the battery. In practical applications, it is necessary to first prepare an inorganic oxide solid electrolyte into a nanodispersion liquid for use. However, in practical applications, the inorganic oxide solid electrolyte is easily deposited at the bottom of the container due to gravity and particle interaction during transportation, storage, and loading of the dispersion liquid, resulting in uneven solid content in the upper and lower layers of the dispersion liquid.Because the material is stored in pipelines for more than 24 hours during transportation, the unstable solid content directly leads to inaccurate loading values ​​during loading, causing difficulties in production. In severe cases, solids may even settle and clump at the bottom of the container, making the material unevenly redispersed or even unusable. In addition, unstable solid content is often accompanied by unstable particle size, and poor particle size stability of the dispersion fluid can easily lead to adverse effects in use. Especially for mass production, a reserve inventory with a storage time of more than 30 days is required. Long-term storage places higher demands on the stability of the dispersion fluid.In order to improve the solid content stability and particle size stability of the solid electrolyte, the solid content of the dispersion liquid used is typically less than 10 wt%, because the prior art generally believes that a low solid content contributes to improving the solid content stability and particle size stability of the dispersion liquid. And the current method of use is immediate preparation and use, which seriously affects the efficiency of actual mass production. The above-mentioned problems seriously hinder the large-scale application of inorganic oxide solid electrolytes. For inorganic oxide solid electrolytes to be used, it is generally required that the solid content of the inorganic oxide solid electrolyte dispersion liquid stabilizes during transportation, storage, and loading / unloading.changes by less than 2% during use. State-of-the-art inorganic oxide solid electrolyte nanodispersion fluids have a comparatively low solid content, typically less than 30 wt% or even less than 10 wt%. However, during transportation, the higher the solvent content, the higher the transportation costs. And when flammable and explosive organic solvents are used, the risk is higher. Therefore, dispersion fluids with low solid content generally involve high transportation costs and high risks. When a dispersion fluid with a very low solid content is used during storage, a large amount of solvent is required, which increases storage costs. During use, it is also possible that the solid content is too low to be used with existing slurry formulas for electrode materials.Therefore, under the premise of ensuring a certain solid content, it is very important to improve the stability of the solid content of inorganic oxide solid electrolyte nanodispersion liquids.

[0003] Currently, methods for improving the stability of the solid content of dispersion liquids and preventing settling mainly include the addition of dispersants, centrifugation, and a process for preparing materials with special morphology.

[0004] CN112876901A discloses a water-dispersible functional ceramic ink prepared by dispersing a Li7La3Zr2O 12 -powder mixture in a dispersion medium of aqueous polyacrylamide solution, the viscosity of which is 3 to 5 mPa·s and the surface tension of which is 55 to 65 mN / m, the ceramic ink having excellent stability, wherein per 100 ml of dispersion medium 6 to 15 g Li7La3Zr2O12 -powder mixture. Due to the low solids content, this invention also suffers from the above-mentioned problems that arise during the transportation, storage, and use of dispersion liquids with low solids content.

[0005] CN102760510B discloses a process for producing an aqueous ATO nanocrystal dispersion liquid without the use of additives. It exhibits high purity, high solid content, good transparency, excellent electrical conductivity, stable storage, and no agglomeration or sedimentation. In this process, an ordinary aqueous ATO dispersion liquid is prepared by grinding with a sand mill and ultrasonic crushing and dispersion. This dispersion liquid is then subjected to high-speed centrifugation to obtain a supernatant with a small particle size. This process is believed to improve the stability of the dispersion liquid at low solid content.The advantage of this method is that no additives are used and the sedimentation of large particles is accelerated by centrifugation. The small particles in the supernatant that do not settle during centrifugation are allowed to stand under normal conditions until they are stable and do not settle easily. The disadvantage is that the solid content of the supernatant is reduced after centrifugation, and the solid in the lower layer is easy to agglomerate after centrifugation. To obtain a dispersion liquid, multi-stage grinding is required again. The process is complex and the entire operation is inefficient. In addition, the dispersion liquid produced by this method has a low solid content.

[0006] CN201810560205.3 discloses a method for producing a Zn2TiO4 dispersion liquid with stable solid content using a dispersant in conjunction with cryogenic centrifugation technology. In this method, a gradient distribution of the solid content occurs during a centrifugation process, resulting in poor solid content uniformity in the overall slurry. It should be noted that even with the use of a dispersant, the stability of the solid content of the dispersion liquid cannot be fully guaranteed. The process of adjusting system stability often requires precise adjustment of various parameters within the system. The effect of long-term storage cannot be achieved by simply adding a dispersant.

[0007] CN113964450A provides a coating fluid for battery separators and a manufacturing method thereof. The coating fluid for battery separators contains ceramic nanowires with a diameter of 1 to 1000 nm and a length of 0.05 to 100 µm. However, a uniform dispersion of nanowires in the dispersion fluid requires the tailored use of other additives and ceramic particles in addition to hydrogen bonding between nanowires, making the formulation complex.

[0008] CN202010494930.2 relates to a method for producing a solid electrolyte film with high mechanical strength. This method comprises the following steps: preparing a solid electrolyte slurry, adding a solid electrolyte and a binder in a specific ratio to a dispersion liquid, and thoroughly mixing to obtain a uniformly dispersed electrolyte slurry, wherein the mass ratio of solid electrolyte to binder is 80 to 100% and 0 to 20%, respectively. However, this invention uses a binder, which impairs the purity of the dispersion system; and the solid electrolyte slurry cannot be stored for an extended period of time.

[0009] In general, the current state of the art cannot simultaneously meet the requirements of simple processing, stable solids content, good redispersibility, and low cost. Furthermore, the current state of the art is technically biased toward the idea that low-solids dispersion fluids are more stable.

[0010] Given the limitations of the above-mentioned techniques, the present patent produces a dispersion liquid with a stable solid content in the range of 40 wt% to 85 wt% without additives. With the inorganic oxide solid electrolyte dispersion liquid, the solid content of which is within this solid content range, the particles do not agglomerate, thus achieving high solid content stability and high particle size stability, which can reduce storage and transportation costs, as well as the cost of use. This dispersion liquid consumes less solvent, which can effectively reduce the production cost of the dispersion liquid.

[0011] An inventive point of the present invention is to provide an inorganic oxide solid electrolyte dispersion liquid having a stable solid content, wherein the inorganic oxide solid electrolyte dispersion liquid consists of a granular inorganic oxide solid electrolyte and a solvent without additives, wherein no modifications to particles of the inorganic oxide solid electrolyte are required.

[0012] The solvent in the dispersion liquid is an aprotic solvent with a polarity of 4 to 8.

[0013] The solids content of the dispersion liquid is 40 wt% to 85 wt%.

[0014] The inorganic oxide solid electrolyte may be at least one of a NASICON type electrolyte, a garnet type electrolyte, a perovskite type electrolyte, an anti-perovskite type electrolyte, a LiSICON type electrolyte, Li 1-x1 Ti1-x1 M1 x1 OPO4, Li 1+x2 H 1-x2 Al(PO4)O 1-y M 2y , LiAlPO4F x3 (OH) 1-x3 and Na-β / β''-Al2O3, wherein M1 is selected from at least one of Nb, Ta and Sb, wherein M is selected from at least one of F, Cl, Br and I, with 0≤x1≤0.7, 0≤x2<1, 0≤x3<1, 0 <y<0,1, wobei es sich bei dem anorganischen Oxid-Festelektrolyten vorzugsweise um mindestens ein von Li 1+x4+n Al x4 Ti 2-x4 Si n (P 1-n / 3 O4)3, Li 1+x4+n Al x4 Ge 2-x4 Si n (P 1-n / 3 O4)3, Na 1+x4 Al x4 Ti 2-x4 Si n (P 1-n / 3 O4)3, Na 1+x5 Zr2Si x5 P 3- x5O 12 , Li 7-z1 La3Zr 2-z1 A2 z1 O 12 , Li 7+z2 La3Zr 2-z2 Y z2 O 12 , Li 7-3z3 Ga z3 La3Zr2O 12 , Li 3x6 La 2 / 3 - x6 TiO3, Li3OCl, Na3OCl, Li 14Zn(GeO4)4, Li 1-x1 Ti 1-x1 M1 x1 OPO4, Li 1+x2 H1- x2 Al(PO4)O 1-y M 2y , LiAlPO4F x3 (OH) 1-x3 and Na-β / β''-Al2O3, wherein M1 is selected from at least one of Nb, Ta and Sb, wherein M is selected from at least one of F, Cl, Br and I, wherein A2 is selected from at least one of Nb, Ta and W, with 0≤x1≤0.7, 0≤x2<1, 0≤x3<1, 0 <x4<0,6, 0≤x5≤3, 0<x6<0,16, 0<y<0,1, 0≤z1≤1, 0≤z2≤1, 0≤z3≤0,3, 0≤n<3.

[0015] The inorganic oxide solid electrolyte in the inorganic oxide solid electrolyte dispersion liquid has a particle size of 50 to 1000 nm.

[0016] Preferably, types of solvents include at least one of N-methylpyrrolidone, N,N-dimethylformamide, dimethylacetamide, 1,3-dioxolane, and dimethyl carbonate.

[0017] Another inventive point of the present invention is to crush the particles of the inorganic oxide solid electrolyte by a grinding process, whereby a stable solid content state is formed within the solid content range after interaction between the particles of the solid electrolyte. The grinding process has a crushing function. A grinding process is not only a process for dispersing the inorganic oxide solid electrolyte, but also a process for promoting interaction between particles. This grinding process reduces the proportion of free solvent in the dispersion liquid and increases the proportion of an inorganic oxide solid electrolyte bound with the solvent, thereby increasing the diffusion difficulty of the inorganic oxide solid electrolyte and achieving the effect of improving the solid content stability.The effect of the present invention cannot be achieved by simple ultrasonic dispersion.

[0018] The grinding process includes at least one of grinding by vertical agitator mill, grinding by drum ball mill and grinding by sand mill.

[0019] After the dispersion liquid has been left standing for 30 days, the solids content of the dispersion liquid shows a change value of less than 2%.

[0020] After the dispersion liquid has been standing for 30 days, the particles of the inorganic oxide solid electrolyte have a particle size change rate of less than 5%.

[0021] Another object of the present invention is to provide a manufacturing method for an inorganic oxide solid electrolyte dispersion liquid, characterized in that the manufacturing method comprises the following steps: (1) Mixing: Putting a grinding media, the granular inorganic oxide solid electrolyte and a solvent into a grinding chamber, wherein a mass ratio of the grinding media, the inorganic oxide solid electrolyte and the solvent is (2000 to 100):100:(17 to 150); (2) Grinding: Grinding the grinding media, the inorganic oxide solid electrolyte and the solvent mixed in the grinding chamber to obtain a dispersion liquid slurry with stable solid content.

[0022] Preferably, the grinding time is 30 minutes to 15 hours;

[0023] Preferably, the linear speed of grinding is greater than or equal to 3 m / s.

[0024] The application of the inorganic oxide solid electrolyte dispersion liquid of the present invention to batteries includes application to at least one of a liquid battery, a hybrid solid-liquid battery, and an all-solid-state battery.

[0025] Specifically, the application of the inorganic oxide solid electrolyte dispersion liquid in batteries includes direct application or application after dilution to at least one of a mixture or doping of positive pole pieces, a surface coating of positive pole pieces, a surface plating of positive electrode particles, and a separator coating, which can improve the safety performance, rate performance, and cycle performance of the battery.

[0026] In the present invention, a dispersion liquid having a stable solids content in the range of 40 wt% to 85 wt% without additives is prepared, wherein the stability of the solids content and the particle size stability are improved by increasing the surface repulsion of particles and delaying the settling rate of inorganic particles.

[0027] Compared to the prior art, the present invention offers the following advantages and outstanding effects: By using the inorganic oxide solid electrolyte dispersion liquid with a stable solid content without additives according to the invention, the problem of the dispersion liquid being unusable due to electrolyte sedimentation during transportation, storage, loading, or use can be solved. The key technical points here are the system adaptation, the manufacturing method, and the appropriate solid content range. This solution has the following advantages: simple processing, low cost, stable solid content and particle size during long-term storage, uniform upper and lower layers of the dispersion liquid, good redispersibility, and the absence of additives, pretreatment of the solid electrolyte surface, and pH adjustment.Compared with the use of other dispersion liquids, a battery using the dispersion liquid of the present invention has better consistency and higher efficiency in grouping batteries.

[0028] The inorganic oxide solid electrolyte dispersion liquid of the present invention is a high-solids nanodispersion liquid. Compared with prior art low-solids dispersion liquids, it does not sediment the solid electrolyte due to reduced solvent content, reduced transportation costs, lower risks, good solid content stability, and good particle size stability. Since less solvent is used during storage, storage costs are reduced. Furthermore, the solid content stability and particle size stability are good, and the solid electrolyte does not settle. During use, the required amount of solid electrolyte dispersion liquid can be accurately added to the slurry as needed, ensuring uniformity between the upper and lower layers of the dispersion liquid.Therefore, the present invention achieves significant economic advantages and utilization effects.

[0029] In the present invention, there is no need to use additives to maintain dispersion stability, which can reduce costs, improve system purity, and reduce the impact on practical applications.

[0030] After increasing the solid content, the present invention reduces the amount of solvent used, thereby reducing the cost of producing the dispersion liquid.

[0031] The present invention does not require any pretreatment of the surface of the ceramic particles.

[0032] The manufacturing process according to the present invention is simple, scalable and compatible with existing milling processes.

[0033] The present invention will be described in detail below in conjunction with specific embodiments. It should be noted that the following embodiments serve only to further illustrate the present invention and should not be construed as limiting the scope of the present invention. Some non-essential improvements and adaptations to the present invention made by those skilled in the art depending on the content of the present invention still fall within the scope of the present invention.

[0034] Test method for the stability of the solid content of the dispersion liquid: A drying method is used to test the solid content of the dispersion liquid, with the test steps for solid content stability being as follows: (1) A prepared dispersion liquid is taken to test its solid content, which is recorded as initial solid content. (2) 100 ml of the dispersion liquid is placed in a 150 ml test bottle, which is then sealed and left to stand for 30 days. After 30 days, 1 ml of the dispersion liquid is taken out of the test bottle at a distance of 5 mm from the liquid level to test its solid content, which is recorded as the solid content value w1 of the upper layer of the dispersion liquid. 1 ml of the dispersion liquid is taken out of the test bottle at a distance of 5 mm from the bottle bottom to test its solid content, which is recorded as the solid content value w2 of the lower layer of the dispersion liquid. (3) The stability S of the solid content of the dispersion liquid is measured by the deviation of the solid content values ​​w1 and w2 of the upper and lower layers, respectively, from the initial solid content value w0. The change value of the solid content in the upper layer is S1=|w1-w0| / w0×100%, while the change value of the solid content in the lower layer is S2=|w2-w0| / w0×100%. The smaller the values ​​of S1 and S2, the more stable the slurry.

[0035] Test method for particle size stability of the dispersion liquid: A nanoparticle measuring device is used to test the particle size of the dispersion liquid, whereby the solvent used is the same as that of the dispersion liquid, and the test steps for particle size stability are as follows: (1) A prepared dispersion liquid is taken to test its particle size, which is recorded as the initial average particle size D0. (2) 100 ml of the dispersion liquid is placed in a 150 ml test bottle, which is then sealed and allowed to stand for 30 days. After 30 days, 1 ml of the dispersion liquid is withdrawn from the test bottle at a distance of 5 mm from the liquid level to test its particle size, which is recorded as the particle size value D1 of the upper layer of the dispersion liquid. (3) 1 ml of the dispersion liquid at a distance of 5 mm from the bottle bottom is taken out of the test bottle to test its particle size, which is recorded as the particle size value D2 of the bottom layer of the dispersion liquid. (4) The particle size stability T of the dispersion liquid is measured by the deviation of the particle size values ​​D1 and D2 of the upper and lower layers, respectively, from the initial particle size value D0. The change value of the particle size of the particles in the upper layer of the slurry is T1=|D1-D0| / D0×100%, while the change value of the particle size of the particles in the lower layer is T2=|D2-D0| / D0×100%. The smaller the values ​​of T1 and T2, the more stable the particle size of the dispersion liquid. Example 1:

[0036] Step 1: 500 parts by weight of zirconium balls, 100 parts by weight of Li 1,4 Al 0,4 Ti 1,6 (PO4)3 powder with a particle size of 3 µm and 67 parts by weight of NMP are placed in a grinding chamber and stirred evenly.

[0037] Step 2: The zirconium balls, the Li 1,4 Al 6,4 Ti 1,6(PO4)3 powder and NMP mixed in the grinding chamber are milled by a drum ball mill into a dispersion liquid slurry with a solid content of 60 wt% and D50 of 306 nm, with the milling time being 12 hours and the milling linear velocity being 6 m / s.

[0038] The prepared dispersion fluid is subjected to a solids content stability test and a particle size stability test. The results are shown in Table 1 and Table 2. Example 2:

[0039] Step 1: 500 parts by weight of zirconium balls, 100 parts by weight of Li7La3Zr2O 12 -Powder with a particle size of 3 µm and 67 parts by weight of NMP are placed in a grinding chamber and stirred evenly.

[0040] Step 2: The zirconium spheres, the Li7La3Zr2O 12-Powder and NMP mixed in the grinding chamber are ground by a sand mill into a dispersion liquid slurry with a solid content of 60 wt% and with D50 of 301 nm, the grinding time being 6 hours and the linear speed of grinding being 8 m / s.

[0041] The prepared dispersion fluid is subjected to a solids content stability test and a particle size stability test. The results are shown in Table 1 and Table 2. Example 3:

[0042] Step 1: 500 parts by weight of zirconium balls, 100 parts by weight of Li 0,35 La 0,55 TiO3 powder with a particle size of 3 µm and 43 parts by weight of DMF are placed in a grinding chamber and stirred evenly.

[0043] Step 2: The zirconium balls, the Li 0,35 La 0,550TiO3 powder and DMF mixed in the grinding chamber are ground by a vertical agitator mill into a dispersion liquid slurry with a solid content of 70 wt% and D50 of 402 nm, with the grinding time being 12 hours and the linear speed of grinding being 7 m / s.

[0044] The prepared dispersion fluid is subjected to a solids content stability test and a particle size stability test. The results are shown in Table 1 and Table 2. Example 4:

[0045] Step 1: 500 parts by weight of zirconium spheres, 100 parts by weight of Li-HAl(PO4)O 0,95 F 0,1 -Powder with a particle size of 3 µm and 67 parts by weight of DMF are placed in a grinding chamber and stirred evenly.

[0046] Step 2: The zirconium spheres containing LiHAl(PO4)O 0,95 F 0,1-Powder and DMF mixed in the grinding chamber are ground by a ball mill into a dispersion liquid slurry with a solid content of 60 wt% and with D50 of 203 nm, the grinding time being 12 hours and the linear speed of grinding being 6 m / s.

[0047] The prepared dispersion fluid is subjected to a solids content stability test and a particle size stability test. The results are shown in Table 1 and Table 2. Example 5:

[0048] Step 1: 500 parts by weight of zirconium balls, 100 parts by weight of Li 1,4 Al 0,4 Ti 1,6 (PO4)3 powder with a particle size of 4 µm and 150 parts by weight of NMP are placed in a grinding chamber and stirred evenly.

[0049] Step 2: The zirconium balls, the Li 1,4 Al 6,4 Ti 1,6(PO4)3 powder and NMP mixed in the grinding chamber are ground by a ball mill into a dispersion liquid slurry with a solid content of 40 wt% and D50 of 307 nm, with the grinding time being 12 hours and the linear speed of grinding being 5 m / s.

[0050] The prepared dispersion fluid is subjected to a solids content stability test and a particle size stability test. The results are shown in Table 1 and Table 2. Example 6:

[0051] Step 1: 500 parts by weight of zirconium balls, 100 parts by weight of Li 1,4 Al 0,4 Ti 1,6 (PO4)3 powder with a particle size of 5 µm and 100 parts by weight of NMP are placed in a grinding chamber and stirred evenly.

[0052] Step 2: The zirconium balls, the Li 1,4 Al 6,4 Ti1,6 (PO4)3 powder and NMP mixed in the grinding chamber are ground by a ball mill into a dispersion liquid slurry with a solid content of 50 wt% and D50 of 300 nm, with the grinding time being 14 hours and the linear speed of grinding being 7 m / s.

[0053] The prepared dispersion fluid is subjected to a solids content stability test and a particle size stability test. The results are shown in Table 1 and Table 2. Example 7:

[0054] Step 1: 500 parts by weight of zirconium balls, 100 parts by weight of Li 1,4 Al 0,4 Ti 1,6 (PO4)3 powder with a particle size of 6 µm and 18 parts by weight of NMP are placed in a grinding chamber and stirred evenly.

[0055] Step 2: The zirconium balls, the Li 1,4 Al 6,4Ti 1,6 (PO4)3 powder and NMP mixed in the grinding chamber are ground by a ball mill into a dispersion liquid slurry with a solid content of 85 wt% and D50 of 811 nm, with the grinding time being 8 hours and the linear speed of grinding being 6 m / s.

[0056] The prepared dispersion fluid is subjected to a solids content stability test and a particle size stability test. The results are shown in Table 1 and Table 2. Example 8:

[0057] Step 1: 100 parts by weight of zirconium balls, 100 parts by weight of Li7La3Zr2O 12 -Powder with a particle size of 3 µm and 67 parts by weight of DMAc are placed in a grinding chamber and stirred evenly.

[0058] Step 2: The zirconium spheres, the Li7La3Zr2O 12-Powder and DMAc mixed in the grinding chamber are ground by a vertical agitator mill into a dispersion liquid slurry with a solid content of 60 wt% and D50 of 1001 nm, with the grinding time being 6 hours and the linear speed of grinding being 4 m / s.

[0059] The prepared dispersion fluid is subjected to a solids content stability test and a particle size stability test. The results are shown in Table 1 and Table 2. Example 9:

[0060] Step 1: 100 parts by weight of zirconium balls, 100 parts by weight of Li7La3Zr2O 12 -Powder with a particle size of 3 µm and 67 parts by weight of DMAc are placed in a grinding chamber and stirred evenly.

[0061] Step 2: The zirconium spheres, the Li7La3Zr2O 12-Powder and DMAc mixed in the grinding chamber are ground by a vertical agitator mill into a dispersion liquid slurry with a solid content of 60 wt% and with D50 of 799 nm, with the grinding time being 8 hours and the linear speed of grinding being 4 m / s.

[0062] The prepared dispersion fluid is subjected to a solids content stability test and a particle size stability test. The results are shown in Table 1 and Table 2. Example 10:

[0063] Step 1: 500 parts by weight of zirconium balls, 100 parts by weight of Li7La3Zr2O 12 -Powder with a particle size of 3 µm and 67 parts by weight of DMAc are placed in a grinding chamber and stirred evenly.

[0064] Step 2: The zirconium spheres, the Li7La3Zr2O 12-Powder and DMAc mixed in the grinding chamber are ground by a sand mill into a dispersion liquid slurry with a solid content of 60 wt% and with D50 of 500 nm, the grinding time being 6 hours and the linear speed of grinding being 7 m / s.

[0065] The prepared dispersion fluid is subjected to a solids content stability test and a particle size stability test. The results are shown in Table 1 and Table 2. Example 11:

[0066] Step 1: 2000 parts by weight of zirconium balls, 100 parts by weight of Li7La3Zr2O 12 -Powder with a particle size of 1 µm and 150 parts by weight of DMAc are placed in a grinding chamber and stirred evenly.

[0067] Step 2: The zirconium spheres, the Li7La3Zr2O 12-Powder and DMAc mixed in the grinding chamber are ground by a sand mill into a dispersion liquid slurry with a solid content of 40 wt% and D50 of 50 nm, with the grinding time being 24 hours and the linear speed of grinding being 8 m / s.

[0068] The prepared dispersion fluid is subjected to a solids content stability test and a particle size stability test. The results are shown in Table 1 and Table 2. Comparison example 1:

[0069] Step 1: 500 parts by weight of zirconium balls, 100 parts by weight of Li 0,35 La 0,55 TiO3 powder with a particle size of 3 µm, 2 parts by weight of PVDF and 122 parts by weight of NMP are placed in a grinding chamber and stirred evenly.

[0070] Step 2: The zirconium balls, the Li 0,35 La 0,55TiO3 powder and NMP mixed in the grinding chamber are ground by a ball mill into a dispersion liquid slurry with a solid content of 45 wt% and D50 of 603 nm, with the grinding time being 8 hours and the linear speed of grinding being 6 m / s.

[0071] The prepared dispersion fluid is subjected to a solids content stability test and a particle size stability test. The results are shown in Table 1 and Table 2. Comparison example 2:

[0072] Step 1: 500 parts by weight of zirconium balls, 100 parts by weight of Li 0,35 La 0,55 TiO3 powder with a particle size of 3 µm, 3 parts by weight of acrylate and 150 parts by weight of NMP are placed in a grinding chamber and stirred evenly.

[0073] Step 2: The zirconium balls, the Li 0,35 La 0,55TiO3 powder and NMP mixed in the grinding chamber are ground by a ball mill into a dispersion liquid slurry with a solid content of 40 wt% and D50 of 299 nm, with the grinding time being 10 hours and the linear speed of grinding being 5 m / s.

[0074] The prepared dispersion fluid is subjected to a solids content stability test and a particle size stability test. The results are shown in Table 1 and Table 2. Comparison example 3:

[0075] Step 1: 100 parts by weight of LiHAl(PO4)O 0,95 F 0,1-Powder with a particle size of 300 nm and 233 parts by weight of NMP are placed in a container, which is then sealed; then the container is placed in an ultrasonic tank and treated with ultrasound for 15 hours, with the solid content being 30 wt%.

[0076] The prepared dispersion fluid is subjected to a solids content stability test and a particle size stability test. The results are shown in Table 1 and Table 2. Comparison example 4:

[0077] Step 1: 500 parts by weight of zirconium balls, 100 parts by weight of Li 1,4 Al 0,4 Ti 1,6 (PO4)3 powder with a particle size of 3 µm and 900 parts by weight of NMP are placed in a grinding chamber and stirred evenly.

[0078] Step 2: The zirconium balls, the Li 1,4 Al 6,4 Ti 1,6(PO4)3 powder and NMP mixed in the grinding chamber are ground by a ball mill into a dispersion liquid slurry with a solid content of 10 wt% and D50 of 300 nm, with the grinding time being 12 hours and the linear speed of grinding being 6 m / s.

[0079] The prepared dispersion fluid is subjected to a solids content stability test and a particle size stability test. The results are shown in Table 1 and Table 2. Table 1: Results of the test for the stability of the solid content of the dispersion liquid: Serial number W0 (wt.%) W1 (wt%) W2 (wt%) S1 (%) S2 (%) Example 1 60 59,15 60,85 1,417% 1,417% Example 2 60 59,10 60,90 1,500% 1,500% Example 3 70 69,00 71,00 1,429% 1,429% Example 4 60 59,10 61,00 1,500% 1,667% Example 5 40 39,22 40,75 1,950% 1,875% Example 6 50 49,15 50,85 1,700% 1,700% Example 7 85 84,20 86,40 0,941 % 1,647% Example 8 60 58,85 61,15 1,917% 1,917% Example 9 60 58,95 61,05 1,750% 1,750% Example 10 60 59,08 61,00 1,533% 1,667% Example 11 40 39,50 40,77 1,250% 1,925% Comparison example 1 45 41,00 48,50 8,889% 7,778% Comparison example 2 40 34,60 46,40 13,500% 16,000% Comparison example 3 30 26,00 35,00 13,333% 16,667% Comparison example 4 10 8,10 12,80 19,000% 28,000% Table 2: Results of the test for the particle size stability of the dispersion liquid: Serial number D0 (nm) D1 (nm) D2 (nm) T1 T2 Example 1 306 303 309 0,980% 0,980% Example 2 301 296 304 1,661% 0,997% Example 3 402 392 409 2,488% 1,741% Example 4 203 197 210 2,956% 3,448% Example 5 307 295 319 3,909% 3,909% Example 6 300 290 311 3,333% 3,667% Example 7 811 827 828 1,973% 2,096% Example 8 1001 954 1048 4,695% 4,695% Example 9 799 776 820 2,879% 2,628% Example 10 500 493 505 1,400% 1,000% Example 11 50 51,5 51,3 3,000% 2,600% Comparison example 1 603 546 658 9,453% 9,121 % Comparison example 2 299 269 341 10,033% 14,047% Comparison example 3 200 182 221 9,000% 10,500% Comparison example 4 300 265 355 11,667% 18,333%

[0080] From the working examples, it can be seen that the dispersion liquid of the present invention has excellent solid content stability and excellent particle size stability, with the solid content stability being less than 2% and the particle size stability being less than 5%. From working examples 1, 5, and 6, it can be seen that with increasing solid content, the solid content stability and the particle size stability increase. From working examples 8 to 10, it can be seen that with decreasing particle size of the electrolyte particles, the solid content stability and the particle size stability increase. In Comparative Examples 1 and 2, the viscosity of the dispersion liquid increased to 15,000 mP·s and 13,000 mP·s, respectively, due to the addition of a thickener.However, since the thickener has only a slight influence on the free solvent ratio, the solid content stability and particle size stability are far worse than those of the dispersion liquid of the present invention. From Comparative Example 3, it is clear that the milling process of the present invention is superior to the ultrasonic process, where the milling process is irreplaceable, and the solid content stability and particle size stability of the dispersion liquid obtained by the ultrasonic process are comparatively poor. Finally, it is clear from Comparative Example 4 that when the solid content is comparatively low, the solid content stability and particle size stability of the dispersion liquid are comparatively poor.

[0081] The prepared dispersion liquid can be mixed into the positive electrode for use, or coated on the surface of the positive pole piece, or applied to the surface of the positive electrode material, which can improve the electrical performance and safety performance of the battery.

[0082] It should be understood that the above embodiments are merely exemplary embodiments illustrating the principles of the present invention, but the present invention is not limited thereto. Those skilled in the art may make various modifications and improvements without departing from the spirit and scope of the present invention. These modifications and improvements are also considered to be within the scope of the present invention. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] CN 112876901A

[0004] CN 102760510B

[0005] CN 201810560205.3

[0006] CN 113964450A

[0007] CN 202010494930.2

[0008]

Claims

[1] Inorganic oxide solid electrolyte dispersion liquid with stable solid content for batteries, characterized by that the inorganic oxide solid electrolyte dispersion liquid consists of a granular inorganic oxide solid electrolyte and a solvent without additives, wherein the solvent in the inorganic oxide solid electrolyte dispersion liquid is an aprotic solvent having a polarity of 4 to 8 and wherein the solid content of the inorganic oxide solid electrolyte dispersion liquid is 40 wt% to 85 wt%. [2] Inorganic oxide solid electrolyte dispersion liquid according to claim 1, characterized by that the inorganic oxide solid electrolyte consists of at least one of a NASICON-type electrolyte, a garnet-type electrolyte, a perovskite-type electrolyte, an anti-perovskite-type electrolyte, a LiSICON-type electrolyte, Li 1-x1 Ti 1-x1 M1 x1 OPO4, Li 1+x2 H1-x2 Al(PO4)O 1-y M 2y , LiAl-PO4F x3 (OH) 1-x3 and Na-β / β''-Al2O3, wherein M1 is selected from at least one of Nb, Ta and Sb, wherein M is selected from at least one of F, Cl, Br and I, with 0≤x1≤0.7, 0≤x2<1, 0≤x3<1, 0 <y<0,1, wobei der anorganische Oxid-Festelektrolyt in der anorganischen Oxid-Festelektrolyt-Dispersionsflüssigkeit eine Partikelgröße von 50 bis 1000 nm aufweist, das Lösungsmittel mindestens eines von N-Methylpyrrolidon, N,N-Dimethylformamid, Dimethylacetamid, 1,3-Dioxolan und Dimethylcarbonat umfasst und der Feststoffgehalt 50 Gew.-% bis 80 Gew.-% beträgt. [3] The inorganic oxide solid electrolyte dispersion liquid according to claim 2, wherein the solid content is 55 wt% to 75 wt%. [4] Inorganic oxide solid electrolyte dispersion liquid according to claim 1, characterized by that the inorganic oxide solid electrolyte consists of at least one of Li 1+x4+n Al x4 Ti2-x4 Si n (P 1-n / 3 O4)3, Li 1+x4+n Al x4 Ge 2-x4 Si n (P 1-n / 3 O4)3, Na 1+x4 Al x4 Ti 2-x4 Si n (P 1-n / 3 O4)3, Na 1+x5 Zr2Si x5 P 3-x5 O12, Li 7-z1 La3Zr 2-z1 A2 z1 O12, Li 7+z2 La3Zr 2-z2 Y z2 O12, Li 7-3z3 Ga z3 La3Zr2O 12 , Li 3x6 La 2 / 3-x6 TiO3, Li3OCl, Na3OCl, Li 14 Zn(GeO4)4, Li 1- x1Ti 1-x1 M1 x1 OPO4, Li 1+x2 H 1-x2 Al(PO4)O 1-y M 2y , LiAlPO4Fx3(OH) 1- x3 and Na-β / β''-Al2O3, M1 is selected from at least one of Nb, Ta and Sb, M is selected from at least one of F, Cl, Br and I and A2 is selected from at least one of Nb, Ta and W, with 0≤x1≤0.7, 0≤x2<1, 0≤x3<1, 0 <x4<0,6, 0≤x5≤3, 0<x6<0,16, 0<y<0,1, 0≤z1≤1, 0≤z2≤1, 0≤z3≤0,3, 0≤n<3. [5] Inorganic oxide solid electrolyte dispersion liquid according to claim 1, characterized by that after the inorganic oxide solid electrolyte dispersion liquid has been left to stand for 30 days, the solid content of the inorganic oxide solid electrolyte dispersion liquid has a change value of less than 2%. [6] A manufacturing method for an inorganic oxide solid electrolyte dispersion liquid according to claim 1, characterized by that the manufacturing process includes: Crushing a granular inorganic oxide solid electrolyte by grinding, and interaction between the crushed particles to form a stable state of solid content. [7] Manufacturing method according to claim 6, characterized by that the manufacturing process specifically includes the following steps: (1) Mixing: Putting a grinding media, the granular inorganic oxide solid electrolyte and a solvent into a grinding chamber, wherein a mass ratio of the grinding media, the inorganic oxide solid electrolyte and the solvent is (2000 to 100):100:(17 to 150); (2) Grinding: Grinding the grinding media, the inorganic oxide solid electrolyte and the solvent mixed in the grinding chamber to obtain a dispersion liquid slurry with stable solid content. [8] Use of an inorganic oxide solid electrolyte dispersion liquid according to any one of claims 1 to 5 in batteries, characterized by that the application includes an application to at least one of a liquid battery, a hybrid solid-liquid battery and a solid-state battery. [9] Application according to claim 8, characterized bythat the application comprises a direct application or an application after dilution to at least one of a mixture or doping of positive pole pieces, a surface coating of positive pole pieces, a surface plating of positive electrode particles and a separator coating.