A fast-ion conductor battery ceramic diaphragm material and a preparation method and application thereof

Abstract

The application relates to a fast-ion-conductor battery ceramic diaphragm material, a preparation method thereof and application thereof in the field of batteries, and belongs to the field of battery diaphragm materials. A slurry of the fast-ion-conductor battery ceramic diaphragm material comprises a fast-ion-conductor synergistic material ABPS4, micron alumina and a solvent; wherein A is an alkali metal ion, B is at least one of Ba 2+ and Ca 2+ ; the cross-section average diameter of the micron alumina is 3-5 microns, preferably 4-5 microns; the solid content (mass percentage) of the slurry is 10-20%, and the solid only comprises the fast-ion-conductor synergistic material ABPS4 and the micron alumina, wherein the mass percentage of the micron alumina in the solid is 70-90%, preferably 85-90%, and the mass percentage of the fast-ion-conductor synergistic material ABPS4 in the solid is 10-30%, preferably 10-15%.

Description

Technical Field

[0001] This invention belongs to the field of battery separator materials, specifically relating to a fast ion conductor battery ceramic separator material, its preparation method, and its application in the battery field. Background Technology

[0002] The separator is a crucial component of a rechargeable battery, significantly impacting its safety, power, and cycle life. Currently, polyolefin separators, such as PE (polyethylene) and PP (polypropylene) membranes, are the most widely used. They offer good chemical stability, excellent mechanical properties, and relatively low cost. However, these separators have low melting points and poor thermal stability, making them prone to thermal shrinkage at high temperatures, potentially leading to short circuits. Furthermore, polyolefin separators lack organic functional groups, resulting in weak adsorption of polar electrolytes and poor wettability. This makes it difficult to retain electrolytes within the separator's micropores for extended periods, thus affecting cycle life. Therefore, modification of polyolefin separators is necessary. One effective modification method involves coating Al2O3 ceramic particles onto a polyolefin-based membrane. The resulting composite membrane effectively improves thermal stability and polar electrolyte wettability, but typically does not significantly improve ionic conductivity and ion transference number, failing to meet the high-current charge and discharge requirements of batteries. Summary of the Invention

[0003] To address the problems of poor thermal stability, poor electrolyte wettability, and low ion mobility faced by separator materials in the battery field, this invention provides a fast-ion conductor ceramic separator material, its preparation method, and its application. This invention, starting from the perspective of multi-level composite material design, successfully prepares a ceramic composite separator material with high ion conductivity, high stability, and enhanced electrolyte wettability by constructing a fast ion transport channel network structure in situ on the surface of the separator base membrane.

[0004] Based on the latest advances in solid-state chemistry, this invention designs a novel class of fast ion conductor sulfur-based compounds, with LiBaPS4 and LiCaPS4 being representative examples. These fast ion conductor materials can be co-prepared with Al2O3 micron-sized particles to form functional ceramic-modified slurries that are then coated onto a membrane substrate. Ba and Ca cations can bond with the hydroxyl anions on the surface of Al2O3 micron-sized particles, forming an ion-conducting network that enhances local stability and ion conductivity. LiBaPS4 and LiCaPS4 fast ion conductors contain lithium ions, which can be directionally transported under an electric field. Sulfur has a relatively low electronegativity relative to oxygen (sulfur: 2.58, oxygen: 3.44), reducing the binding force on lithium and sodium ions and thus enhancing their transport performance. These fast ion conductor materials and Al2O3 micron-sized particles can synergistically adsorb electrolyte, enhancing electrolyte wetting properties. Therefore, by introducing novel fast ion conductor sulfur-based compounds as ceramic modification slurries for coating, the thermal stability, electrolyte wettability, and ion mobility of the separator base film can be effectively improved, and the performance upgrades of the battery, such as high safety, long life, and high-rate charge and discharge, can be achieved.

[0005] Specifically, in a first aspect, the present invention provides a slurry for a fast-ion conductor battery ceramic separator material, characterized in that it comprises: a fast-ion conductor enhancement material ABPS4, micron-sized alumina, and a solvent; wherein A is an alkali metal ion, and B is Ba. 2+ and Ca 2+ At least one of the following: the cross-sectional average diameter of the micron-sized alumina is 3-5 micrometers, preferably 4-5 micrometers; the solid content (mass percentage) of the slurry is 10-20%, and the solids contain only fast ion conductor enhancing material ABPS4 and micron-sized alumina, wherein the micron-sized alumina accounts for 70%-90% of the solid mass percentage, preferably 85%-90%, and the fast ion conductor enhancing material ABPS4 accounts for 10%-30% of the solid mass percentage, preferably 10%-15%.

[0006] Preferably, in the fast ion conductor enhancement material ABPS4, A is Li. + Na + and K + At least one of the following; alkali metal A can react with OH groups on the surface of micron-sized alumina. - Combined with enhanced stability, the low electronegativity of sulfide ions is beneficial to Li + Na + K + Rapid diffusion, synergistically forming fast ion conductor channels.

[0007] Preferably, the solvent in the slurry is at least one of ethanol, isopropanol, glycerol, water, acetone, and NMP, and more preferably ethanol and glycerol.

[0008] Preferably, the slurry further includes a binder, which includes polyacrylate materials, carboxymethyl cellulose, PVDF, and preferably polyacrylate materials.

[0009] Preferably, the amount of the binder added is 0.5% to 3% of the total mass of solids and solvents.

[0010] Preferably, the mixing ratio of the fast ion conductor enhancing material ABPS4, micron-sized alumina solid, binder, and solvent is 10–20: 0.5–3: 77–89.5.

[0011] Secondly, the present invention provides a fast ion conductor battery ceramic separator, characterized in that the fast ion conductor battery ceramic separator includes a base film and a functional ceramic film layer formed by coating the slurry on the base film.

[0012] Preferably, the polyolefin membrane base material includes polyethylene, polypropylene, and polypropylene-polyethylene composite material, with polyethylene and polypropylene being the most preferred.

[0013] Preferably, the thickness of the base film is 7 micrometers, and the thickness of the functional ceramic film layer is 1 to 3 micrometers.

[0014] Thirdly, the present invention provides an application of a fast-ion conductor battery ceramic separator material, characterized in that the fast-ion conductor battery ceramic separator can be used in lithium-ion batteries, sodium-ion batteries, solid-state batteries, dual-ion batteries, and supercapacitors.

[0015] Beneficial effects

[0016] 1) The ceramic composite membrane material prepared by this invention has the characteristics of high ionic conductivity, high stability, and high electrolyte wettability;

[0017] 2) The process of this invention is compatible with the traditional ceramic composite membrane coating process. Only the modified slurry formula is changed, and no special changes are required to the production process. Production personnel will not need to make significant changes to the membrane preparation process. The operation steps are simple and efficient, and the requirements for process technology are low, which is conducive to the realization of industrial-scale preparation.

[0018] 3) By introducing a novel fast-ion conductor sulfur-based compound as a ceramic modification slurry for coating, this invention can effectively improve the thermal stability, electrolyte wettability, and ion mobility of the separator base film, thereby achieving performance upgrades such as high safety, long life, and high-rate charge and discharge of the battery. Attached Figure Description

[0019] Figure 1 This is a SEM image of the fast ion conductor sulfur-based compound LiBaPS4 from Example 1.

[0020] Figure 2 This is a TEM image of LiCaPS4, a fast ion conductor sulfur-based compound, from Example 2. Detailed Implementation

[0021] To further illustrate the invention's content, features, and practical effects, the invention will be described in detail below with reference to embodiments. It should be noted that the modification methods of the invention are not limited to these specific implementation methods. Equivalent substitutions and modifications made by those skilled in the art based on their understanding of the invention, without departing from its spirit and essence, are also within the scope of protection claimed by this invention.

[0022] A method for preparing a ceramic separator material for fast-ion conductor batteries, the specific steps of which are as follows:

[0023] (1) Preparation of functional ceramic modified slurry: The prepared fast ion conductor enhancement material ABPS4, micron alumina and binder are mixed in a solvent in proportion and the slurry is dispersed evenly using a grinding device.

[0024] (2) The slurry from step 1 is coated onto the separator base membrane and dried to obtain the fast ion conductor battery ceramic separator material.

[0025] In some implementations, the fast ion conductor enhancement material ABPS4, wherein A is an alkali metal ion, including Li + Na + K + At least one of the following, selected according to the battery type, wherein B includes Ba. 2+ Ca 2+ At least one of, wherein Ba is preferred 2+ .

[0026] In some implementation processes, the preparation of the fast ion conductor enhancement material ABPS4 can be as follows: As, BS, red phosphorus, and sulfur powder are weighed according to stoichiometric ratios, ground evenly, and placed into a self-made quartz tube. After vacuuming, the quartz tube is sealed with an oxyhydrogen flame. The sealed quartz tube is placed in a muffle furnace and sintered at 1300–1400℃ for 1–10 h, with a heating rate of 5℃ / min. After sintering, it is naturally cooled to room temperature to obtain ABPS4 material. The ABPS4 particles are refined using a planetary ball mill to obtain ABPS4 slurry. The ball mill jar is filled with argon gas for protection and then sealed. The ball milling speed is 400 rpm / min, and the milling time is 1–10 h to obtain ABPS4.

[0027] In the preparation of the functional ceramic modified slurry, the mixing ratio of the fast ion conductor enhancing material ABPS4, micron-sized alumina solid, binder, and solvent is 10–20:0.5–3:77–89.5. Within this range, the solid dispersion is most uniform, and the coating effect is best. A slurry with a solid content (including ABPS4 and micron-sized alumina) of 10–20% is obtained, wherein the micron-sized alumina accounts for 70%–90% of the solid mass, preferably 85%–90%. If the mass percentage of micron-sized alumina is greater than 90%, the solid is difficult to disperse uniformly in the slurry; if the mass percentage of micron-sized alumina is less than 70%, the mechanical strength of the separator cannot be guaranteed. The average diameter of the micron-sized alumina cross-section is 3–5 micrometers, preferably 4–5 micrometers. If the diameter of the alumina is too large, it will adversely affect the cycle life of the battery cell; if the diameter is too small, it will adversely affect the rate capability of the battery cell.

[0028] Preferably, in the functional ceramic modified slurry, the solvent is at least one of ethanol, isopropanol, glycerol, water, acetone, and NMP, with ethanol and glycerol being preferred; the binder includes polyacrylate materials, carboxymethyl cellulose, and polyvinylidene fluoride (PVDF), with polyacrylate materials being preferred, and the amount added accounts for 0.5-3% of the total mass percentage of solids and solvents.

[0029] Preferably, the mixing method includes one or more of solution stirring, mechanical stirring, hydrothermal mixing, microsolution reaction, and three-dimensional mixing, with solution stirring being the preferred method.

[0030] Preferably, the grinding method includes one or more of ball milling, sand milling, rod milling, and wet grinding, with wet grinding being the preferred method.

[0031] In some implementations, the diaphragm base membrane material includes polyethylene, polypropylene, and polypropylene-polyethylene composites, with polyethylene and polypropylene being preferred. The thickness of the base membrane is 7 micrometers. PE and PP membranes have good chemical stability, excellent mechanical properties, and relatively low cost; however, these membranes have low melting points and poor thermal stability, and are prone to thermal shrinkage at high temperatures, leading to short circuits. Therefore, polyolefin membranes are chosen for modification. Coating can be performed using a coating machine, followed by drying at 60–80°C for 1–4 hours. This forms a functional ceramic membrane layer on the base membrane. The number of coatings can be controlled as needed, thereby controlling the thickness of the functional ceramic membrane layer. For example, the thickness of the functional ceramic membrane layer is preferably 1–3 micrometers. Within this range, the diaphragm performance is optimal. If the thickness of the functional ceramic membrane layer is too large, it will cause a decrease in diaphragm toughness, thus affecting performance; if it is too small, the diaphragm's effect will be insignificant.

[0032] Example 1

[0033] Preparation of a fast ion conductor sulfur-based compound LiBaPS4: 0.23g Li2S, 1.7g BaS, 0.31g red phosphorus, and 0.8g sulfur powder were weighed according to a stoichiometric ratio of 1:2:2:5 and ground evenly. The mixture was added to a self-made alumina tube, sealed under vacuum with an oxyhydrogen flame, and sintered at 1300℃ for 10h. After naturally cooling to room temperature, the tube was ball-milled under argon protection for 1h. After cooling, the fast ion conductor sulfur-based compound LiBaPS4 was obtained. The surface morphology of the sample was characterized by scanning electron microscopy.

[0034] Figure 1 This is a SEM image of the fast ion conductor sulfur-based compound LiBaPS4 from Example 1. As can be seen from the image, the sulfur-based compound LiBaPS4 particles are irregularly spherical, with a size of 4–5 micrometers, and their uneven distribution is beneficial for uniform distribution in solution.

[0035] Example 2

[0036] Preparation of a fast ion conductor sulfur-based compound, LiCaPS4. 0.23 g Li₂S, 0.72 g CaS, 0.31 g red phosphorus, and 0.8 g sulfur powder were weighed according to a stoichiometric ratio of 1:2:2:5 and ground evenly. The mixture was added to a self-made alumina tube, sealed under vacuum with an oxyhydrogen flame, and sintered at 1350 °C for 10 h. After natural cooling to room temperature, the tube was ball-milled under argon protection for 1 h. Upon cooling, the fast ion conductor sulfur-based compound LiCaPS4 was obtained. The morphology and microstructure of the sample were characterized using transmission electron microscopy.

[0037] Figure 2 This is a TEM image of the fast ion conductor sulfur-based compound LiCaPS4 in Example 2. The image shows that the sulfur-based compound LiCaPS4 has a well-formed crystal lattice and high material purity.

[0038] Example 3

[0039] (1) Preparation of a functional ceramic modification slurry containing 10% solids of fast ion conductor sulfur-based compound LiBaPS4. 0.1g of LiBaPS4 powder and 0.9g of micron-sized alumina with a diameter of 5 micrometers were weighed at a mass ratio of 1:9. 5mL of ethanol was added and mechanically stirred to mix them completely. Then, 0.075g of 1.5% polyacrylate binder was added to obtain the functional ceramic modification slurry.

[0040] (2) A ceramic-PP composite separator material for fast-ion conductor batteries. The functional ceramic modified slurry from step (1) is coated once onto a 7-micron thick polypropylene separator base membrane using a coating machine. After drying and slicing, the ceramic-PP composite separator material for fast-ion conductor batteries is obtained. The drying process refers to continuous drying at 80°C for 3 hours; the thickness of the coated slurry is approximately 2 microns.

[0041] Example 4

[0042] (1) Preparation of a functional ceramic modification slurry containing 15% solids of fast ion conductor sulfur-based compound LiBaPS4. 0.15g of LiBaPS4 powder and 0.85g of micron-sized alumina with a diameter of 5 μm were weighed according to a mass ratio of 1.5:8.5. 5mL of ethanol was added and mechanically stirred to mix them completely. Then, 0.075g of 1.5% polyacrylate binder was added to obtain the functional ceramic modification slurry.

[0043] (2) A ceramic-PP composite separator material for fast-ion conductor batteries. The functional ceramic modified slurry from step (1) is coated once onto a 7-micron thick polypropylene separator base membrane using a coating machine. After drying and slicing, the ceramic-PP composite separator material for fast-ion conductor batteries is obtained. The drying process refers to continuous drying at 65°C for 2 hours; the thickness of the coated slurry is approximately 1 micron.

[0044] Example 5

[0045] (1) Preparation of a functional ceramic modification slurry of LiBaPS4, a fast ion conductor sulfur-based compound with a solid content of 20%. 0.2 g of LiBaPS4 powder and 0.8 g of micron-sized alumina with a diameter of 5 micrometers were weighed at a mass ratio of 2:8. 5 mL of ethanol was added and mechanically stirred to mix them completely. Then, 0.1 g of polyacrylate binder with a mass fraction of 2% was added to obtain the functional ceramic modification slurry.

[0046] (2) A ceramic-PP composite separator material for fast-ion conductor batteries. The functional ceramic modified slurry from step (1) is coated once onto a 7-micron thick polypropylene separator base membrane using a coating machine. After drying and slicing, the ceramic-PP composite separator material for fast-ion conductor batteries is obtained. The drying process refers to continuous drying at 80°C for 3 hours; the thickness of the coated slurry is approximately 3 microns.

[0047] Example 6

[0048] (1) Preparation of a functional ceramic modification slurry containing 10% solids of fast ion conductor sulfur-based compound LiCaPS4. 0.1g of LiCaPS4 powder and 0.9g of micron-sized alumina with a diameter of 5 micrometers were weighed at a mass ratio of 1:9. 5mL of ethanol was added and mechanically stirred to mix them completely. Then, 0.05g of 1% polyacrylate binder was added to obtain the functional ceramic modification slurry.

[0049] (2) A ceramic-PP composite separator material for fast-ion conductor batteries. The functional ceramic modified slurry from step (1) is coated once onto a 7-micron thick polypropylene separator base membrane using a coating machine. After drying and slicing, the ceramic-PP composite separator material for fast-ion conductor batteries is obtained. The drying process refers to a continuous drying time of 4 hours at 65°C; the thickness of the coated slurry is approximately 1 micron.

[0050] Example 7

[0051] (1) Preparation of a functional ceramic modification slurry containing 20% ​​solids of fast ion conductor sulfur-based compound LiCaPS4. 0.2g of LiCaPS4 powder and 0.8g of micron-sized alumina with a diameter of 5 micrometers were weighed at a mass ratio of 2:8. 5mL of ethanol was added and mechanically stirred to mix them completely. Then, 0.1g of 2% polyacrylate binder was added to obtain the functional ceramic modification slurry.

[0052] (2) A ceramic-PP composite separator material for fast-ion conductor batteries. The functional ceramic modified slurry from step (1) is coated once onto a 7-micron thick polypropylene separator base membrane using a coating machine. After drying and slicing, the ceramic-PP composite separator material for fast-ion conductor batteries is obtained. The drying process refers to continuous drying at 60°C for 1 hour; the thickness of the coated slurry is approximately 1 micron.

[0053] Example 8

[0054] (1) Preparation of a functional ceramic modification slurry containing 10% solids of fast ion conductor sulfur-based compound LiBaPS4. 0.1g of LiBaPS4 powder and 0.9g of micron-sized alumina with a diameter of 5 micrometers were weighed at a mass ratio of 1:9. 5mL of ethanol was added and mechanically stirred to mix them completely. Then, 0.05g of 1% polyacrylate binder was added to obtain the functional ceramic modification slurry.

[0055] (2) A ceramic-PE composite separator material for fast-ion conductor batteries. The functional ceramic modified slurry from step (1) is coated once onto a 7-micron thick polyethylene separator base membrane using a coating machine. After drying and slicing, the ceramic-PE composite separator material for fast-ion conductor batteries is obtained. The drying process refers to continuous drying at 75°C for 2 hours; the thickness of the coated slurry is approximately 2 microns.

[0056] Example 9

[0057] (1) Preparation of a functional ceramic modification slurry containing 15% solids of fast ion conductor sulfur-based compound LiBaPS4. 0.15g of LiBaPS4 powder and 0.85g of micron-sized alumina with a diameter of 5 μm were weighed according to a mass ratio of 1.5:8.5. 5mL of ethanol was added and mechanically stirred to mix them completely. Then, 0.075g of 1.5% polyacrylate binder was added to obtain the functional ceramic modification slurry.

[0058] (2) A ceramic-PE composite separator material for fast-ion conductor batteries. The functional ceramic modified slurry from step (1) is coated once onto a 7-micron thick polyethylene separator base membrane using a coating machine. After drying and slicing, the ceramic-PE composite separator material for fast-ion conductor batteries is obtained. The drying process refers to a continuous drying time of 1 hour at 60°C; the thickness of the coated slurry is approximately 2 microns.

[0059] Example 10

[0060] (1) Preparation of a functional ceramic modification slurry of LiBaPS4, a fast ion conductor sulfur-based compound with a solid content of 20%. 0.2 g of LiBaPS4 powder and 0.8 g of micron-sized alumina with a diameter of 5 micrometers were weighed at a mass ratio of 2:8. 5 mL of ethanol was added and mechanically stirred to mix them completely. Then, 0.1 g of polyacrylate binder with a mass fraction of 2% was added to obtain the functional ceramic modification slurry.

[0061] (2) A ceramic-PE composite separator material for fast-ion conductor batteries. The functional ceramic modified slurry from step (1) is coated once onto a 7-micron thick polyethylene separator base membrane using a coating machine. After drying and slicing, the ceramic-PE composite separator material for fast-ion conductor batteries is obtained. The drying process refers to a continuous drying time of 4 hours at 80°C; the thickness of the coated slurry is approximately 2 microns.

[0062] Example 11

[0063] (1) Preparation of a functional ceramic modification slurry containing 10% solids of fast ion conductor sulfur-based compound LiCaPS4. 0.1g of LiCaPS4 powder and 0.9g of micron-sized alumina with a diameter of 5 micrometers were weighed at a mass ratio of 1:9. 5mL of ethanol was added and mechanically stirred to mix them completely. Then, 0.05g of 1% polyacrylate binder was added to obtain the functional ceramic modification slurry.

[0064] (2) A ceramic-PE composite separator material for fast-ion conductor batteries. The functional ceramic modified slurry from step (1) is coated once onto a 7-micron thick polyethylene separator base membrane using a coating machine. After drying and slicing, the ceramic-PE composite separator material for fast-ion conductor batteries is obtained. The drying process refers to a continuous drying time of 3 hours at 75°C; the thickness of the coated slurry is approximately 2 microns.

[0065] Example 12

[0066] (1) Preparation of a functional ceramic modification slurry containing 20% ​​solids of fast ion conductor sulfur-based compound LiCaPS4. 0.2g of LiCaPS4 powder and 0.8g of micron-sized alumina with a diameter of 5 micrometers were weighed at a mass ratio of 2:8. 5mL of ethanol was added and mechanically stirred to mix them completely. Then, 0.1g of 2% polyacrylate binder was added to obtain the functional ceramic modification slurry.

[0067] (2) A ceramic-PE composite separator material for fast-ion conductor batteries. The functional ceramic modified slurry from step (1) is coated once onto a 7-micron thick polyethylene separator base membrane using a coating machine. After drying and slicing, the ceramic-PE composite separator material for fast-ion conductor batteries is obtained. The drying process refers to a continuous drying time of 1 hour at 60°C; the thickness of the coated slurry is approximately 2 microns.

[0068] Comparative Example 1

[0069] (1) Preparation of a functional ceramic modified slurry without fast ion conductor sulfur-based compounds. Weigh 1g of micron-sized alumina with a diameter of 5 micrometers, add 5mL of ethanol and mechanically stir to mix it completely and evenly. Then add 0.075g of polyacrylate binder with a mass fraction of 1.5% to obtain a functional ceramic modified slurry of ordinary alumina micro powder.

[0070] (2) Preparation of a common alumina micron powder battery ceramic PP composite separator material. The slurry from step (1) is coated once on a 7-micron thick polypropylene separator base film using a coating machine. After drying and slicing, the common alumina micron powder battery ceramic PP composite separator material is obtained. The drying process refers to continuous drying at 70°C for 3 hours; the thickness of the coated slurry is approximately 1 micron.

[0071] Comparative Example 2

[0072] (1) Preparation of a functional ceramic modified slurry without fast ion conductor sulfur-based compounds. Weigh 1g of micron-sized alumina with a diameter of 5 micrometers, add 5mL of ethanol and mechanically stir to mix it completely and evenly. Then add 0.1g of polyacrylate binder with a mass fraction of 2% to obtain a common alumina micron-sized functional ceramic modified slurry.

[0073] (2) Preparation of a common alumina micron powder battery ceramic PE composite separator material. The slurry from step (1) is coated once on a 7-micron thick polyethylene separator base film using a coating machine. After drying and slicing, the common alumina micron powder battery ceramic PE composite separator material is obtained. The drying process refers to continuous drying at 70°C for 1 hour; the thickness of the coated slurry is approximately 2 microns.

[0074] Comparative Example 3

[0075] (1) Preparation of a functional ceramic modification slurry containing 10% solids of fast ion conductor sulfur-based compound LiBaPS4. 0.1g of LiBaPS4 powder and 0.9g of micron-sized alumina with a diameter of 5 micrometers were weighed at a mass ratio of 1:9. 5mL of ethanol was added and mechanically stirred to mix them completely. Then, 0.075g of 1.5% polyacrylate binder was added to obtain the functional ceramic modification slurry.

[0076] (2) A ceramic-PP composite separator material for fast-ion conductor batteries. The functional ceramic modified slurry from step (1) is coated twice on a 7-micron thick polypropylene separator base membrane using a coating machine. After drying and slicing, the ceramic-PP composite separator material for fast-ion conductor batteries is obtained. The drying process refers to a continuous drying time of 4 hours at 80°C; the thickness of the coated slurry is approximately 5 microns.

[0077] The composite separator materials prepared in Examples 3-12 and Comparative Examples 1-3 were installed in lithium-ion coin cells (CR2016) and tested. The negative electrode was a 1 mm thick, 14 mm diameter lithium metal sheet, and the positive electrode was a commercial lithium cobalt oxide material. Assembly was performed in a glove box, where oxygen and water vapor levels were below 0.1 ppm. Electrochemical testing was conducted using a CHI760e electrochemical workstation from Shanghai Chenhua Co., Ltd., and a LAND-CT2001C battery testing system from Wuhan Landian Co., Ltd. The test voltage range was 3-4.2 V, where 1C = 140 mA g. -1 The battery rate performance and cycle life were tested, and the results are shown in the table below:

[0078]

[0079]

[0080] Ba and Ca cations can bond with hydroxyl anions on the surface of Al2O3 micron-sized particles to form an ionic conductive network, enhancing local stability and ionic conductivity. LiBaPS4 and LiCaPS4 fast ion conductors contain lithium ions, which can be directionally transported under an electric field. Sulfur has a relatively low electronegativity relative to oxygen, reducing its binding force on lithium and sodium ions, thereby enhancing lithium and sodium ion transport performance. These fast ion conductor materials and Al2O3 micron-sized particles can synergistically adsorb electrolyte, enhancing electrolyte wetting performance. As can be seen from the above-mentioned test battery rate performance and cycle life tables, the high-rate battery performance and cycle life of Examples 1-12 are significantly better than those of Comparative Examples 1-3, while the low-rate battery performance is slightly better. Therefore, it is successfully demonstrated that the fast ion conductor battery ceramic separator material of this invention can effectively improve the performance of low-rate batteries, high-rate batteries, and battery cycle life. Furthermore, the separator performance is optimal when the thickness of the functional ceramic membrane layer is in the range of 1-3 microns. Excessive membrane thickness will cause a decrease in separator toughness, thus affecting cycle life.

[0081] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A slurry for a ceramic separator material for fast-ion conductor batteries, characterized in that, include: Fast ion conductor enhancement material ABPS4, micron-sized alumina and solvent; Where A is an alkali metal ion, and B is Ba. 2+ and Ca 2+ At least one of the following: the average cross-sectional diameter of the micron-sized alumina is 3-5 microns; the solid content of the slurry is 10-20% by mass, and the solids contain only fast ion conductor enhancement material ABPS4 and micron-sized alumina, wherein the micron-sized alumina accounts for 70%-90% of the solids by mass, and the fast ion conductor enhancement material ABPS4 accounts for 10%-30% of the solids by mass.

2. The slurry according to claim 1, characterized in that, The average diameter of the cross-section of the micron-sized alumina is 4-5 micrometers.

3. The slurry according to claim 1, characterized in that, The micron-sized alumina accounts for 85% to 90% of the solid mass.

4. The slurry according to claim 1, characterized in that, The fast ion conductor enhancement material ABPS4 accounts for 10%~15% of the solid mass.

5. The slurry according to claim 1, characterized in that, In the fast ion conductor enhancement material ABPS4, A is Li. + Na + and K + At least one of them.

6. The slurry according to claim 1, characterized in that, The solvent is at least one of ethanol, isopropanol, glycerol, water, acetone, and NMP.

7. The slurry according to claim 1, characterized in that, It also includes an adhesive, which includes polyacrylate, carboxymethyl cellulose, and polyvinylidene fluoride (PVDF).

8. The slurry according to claim 7, characterized in that, The amount of the binder added is 0.5-3% of the total mass of solids and solvents.

9. The slurry according to claim 7, characterized in that, The mixing ratio of the fast ion conductor enhancement material ABPS4, micron-sized alumina solid, binder, and solvent is 10~20:0.5~3:77~89.

5.

10. A ceramic separator for fast-ion conductor batteries, characterized in that, The fast-ion conductor battery ceramic separator includes a base membrane and a functional ceramic membrane layer formed by coating the base membrane with the slurry described in any one of claims 1 to 9.

11. The fast-ion conductor battery ceramic separator according to claim 10, characterized in that, The base film is made of polyethylene, polypropylene, or a polypropylene-polyethylene composite material.

12. The fast-ion conductor battery ceramic separator according to claim 10, characterized in that, The thickness of the base film is 7 micrometers, and the thickness of the functional ceramic film layer is 1 to 3 micrometers.

13. The application of the fast-ion conductor battery ceramic separator according to any one of claims 10 to 12, characterized in that, The fast-ion conductor battery ceramic separator can be used in lithium-ion batteries, sodium-ion batteries, solid-state batteries, dual-ion batteries, and supercapacitors.

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