Solid-state batteries and their preparation methods

Abstract

This application discloses a solid-state battery and its preparation method, belonging to the field of battery technology. The preparation method provided in this application first involves uniformly mixing at least one of an oxide solid electrolyte and a sulfide solid electrolyte with a polymer solid electrolyte, a positive electrode material, or a negative electrode material to prepare positive and negative electrode slurries. Then, a composite electrolyte slurry is prepared by mixing at least one of the oxide solid electrolyte and the sulfide solid electrolyte with the polymer solid electrolyte. Next, positive and negative electrode sheets are prepared using the positive and negative electrode slurries and the composite electrolyte slurry. Finally, the positive and negative electrode sheets are heat-bonded and aged to obtain the solid-state battery. This preparation method uses heat bonding to prepare the solid-state battery, reducing the internal stress between the solid electrolyte layer and the electrodes, creating a path for ion transport at the positive and negative electrode interfaces, reducing interfacial impedance, and improving the ion transport capacity during charging and discharging, thereby improving the charging and discharging efficiency of the solid-state battery.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a solid-state battery and its preparation method. Background Technology

[0002] With the development of new energy vehicles, people's requirements for vehicle safety are constantly increasing, posing a huge challenge to the safety of power batteries. Previously, liquid batteries were widely used in the market, but they are prone to leakage. Once a leak occurs, short-circuit, or is impacted, it can cause a fire or even an explosion, posing a significant safety risk. Therefore, solid-state batteries have become a key area of ​​research.

[0003] In related technologies, solid-state batteries are prepared through in-situ polymerization. The principle is to use in-situ polymerization technology inside the battery to generate a solid electrolyte through a polymerization reaction. However, solid-state batteries prepared in this way have poor interfacial contact, resulting in low charge and discharge efficiency. Summary of the Invention

[0004] This application provides a solid-state battery and its fabrication method, which can improve the charge and discharge efficiency of the solid-state battery. The technical solution is as follows:

[0005] On the one hand, a method for preparing a solid-state battery is provided, the method comprising:

[0006] At least one of oxide solid electrolyte and sulfide solid electrolyte, polymer solid electrolyte and positive electrode material are mixed in a first ratio to obtain positive electrode slurry;

[0007] At least one of the oxide solid electrolyte and the sulfide solid electrolyte, the polymer solid electrolyte and the negative electrode material are mixed in a second ratio to obtain a negative electrode slurry;

[0008] At least one of the oxide solid electrolyte and the sulfide solid electrolyte and the polymer solid electrolyte are mixed in a third ratio to obtain a composite electrolyte slurry;

[0009] A positive electrode sheet and a negative electrode sheet are prepared using the positive electrode slurry, the negative electrode slurry, and the composite electrolyte slurry.

[0010] The positive electrode and the negative electrode are thermally bonded and aged to obtain a solid-state battery.

[0011] In one possible implementation, the preparation of the positive electrode sheet and the negative electrode sheet using the positive electrode slurry, the negative electrode slurry, and the composite electrolyte slurry includes:

[0012] The positive electrode slurry is coated onto the positive electrode current collector to obtain the positive electrode sheet; the negative electrode slurry and the composite electrolyte slurry are coated onto the negative electrode current collector to obtain the negative electrode sheet; or...

[0013] The positive electrode slurry and the composite electrolyte slurry are coated onto the positive electrode current collector to obtain the positive electrode sheet, and the negative electrode slurry is coated onto the negative electrode current collector to obtain the negative electrode sheet; or...

[0014] The positive electrode slurry and the composite electrolyte slurry are coated onto the positive electrode current collector to obtain the positive electrode sheet, and the negative electrode slurry and the composite electrolyte slurry are coated onto the negative electrode current collector to obtain the negative electrode sheet.

[0015] In another possible implementation, the coating thickness of the positive electrode slurry on the positive electrode sheet and the coating thickness of the negative electrode slurry on the negative electrode sheet are both less than 200 μm, and the coating thickness of the composite electrolyte slurry on any electrode sheet is less than 100 μm.

[0016] In another possible implementation, the step of coating the negative electrode slurry and the composite electrolyte slurry onto the negative electrode current collector to obtain the negative electrode sheet includes:

[0017] The negative electrode slurry and the composite electrolyte slurry are coated onto the negative electrode current collector using a double-layer coating method to obtain the negative electrode sheet.

[0018] In another possible implementation, the first ratio is: 0 < at least one of the oxide solid electrolyte and the sulfide solid electrolyte ≤ 30%, 0 < the polymer solid electrolyte ≤ 30%, and 60% ≤ the cathode material < 100%.

[0019] In another possible implementation, the third ratio is: 0 < at least one of the oxide solid electrolyte and the sulfide solid electrolyte < 100%, 0 < the polymer solid electrolyte < 100%, and the sum of the masses of at least one of the oxide solid electrolyte and the sulfide solid electrolyte and the polymer solid electrolyte is 100%.

[0020] In another possible implementation, the step of thermally bonding and aging the positive electrode and the negative electrode to obtain a solid-state battery includes:

[0021] The positive electrode and the negative electrode are assembled by stacking or winding, under a temperature of 40℃~200℃ and a pressure ≥10N / cm. 2Under certain conditions, the positive electrode and the negative electrode are thermally bonded together for a time of ≥30 minutes, and the solid-state battery is obtained after aging.

[0022] In another possible implementation, the cathode material includes one or two of lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate, and lithium manganese iron phosphate.

[0023] The negative electrode material includes one or two of graphite, silicon oxide, silicon, lithium, graphene, hard carbon, and soft carbon.

[0024] In another possible implementation, the oxide solid electrolyte includes at least one of perovskite oxide solid electrolyte, sodium superion conductor oxide solid electrolyte, lithium superion conductor oxide solid electrolyte, and garnet oxide solid electrolyte;

[0025] The sulfide solid electrolyte includes at least one of perovskite-type sulfide solid electrolyte, sodium superion conductor-type sulfide solid electrolyte, lithium superion conductor-type sulfide solid electrolyte, and garnet-type sulfide solid electrolyte.

[0026] The polymer solid electrolyte includes at least one of polyethylene oxide, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, polypropylene oxide, polyvinylidene chloride, and monoionic polymer solid electrolyte.

[0027] On the other hand, a solid-state battery is provided, which is prepared by any of the preparation methods described above.

[0028] This application provides a method for preparing a solid-state battery. The method involves first uniformly mixing at least one of an oxide solid-state electrolyte and a sulfide solid-state electrolyte with a polymer solid-state electrolyte, a positive electrode material, or a negative electrode material to prepare positive and negative electrode slurries. Then, a composite electrolyte slurry is prepared by mixing at least one of the oxide solid-state electrolyte and the sulfide solid-state electrolyte with the polymer solid-state electrolyte. Next, positive and negative electrode sheets are prepared using the positive and negative electrode slurries and the composite electrolyte slurry. Finally, the positive and negative electrode sheets are heat-bonded and aged to obtain the solid-state battery. This method, through heat bonding, reduces the internal stress between the solid electrolyte layer and the electrodes, creating a path for ion transport at the positive and negative electrode interfaces, reducing interfacial impedance, and improving the ion transport capacity during charging and discharging, thereby increasing the charging and discharging efficiency of the solid-state battery.

[0029] It should be understood that the above general description and the following detailed description are merely exemplary and do not limit this disclosure. Attached Figure Description

[0030] Figure 1This is a flowchart of a solid-state battery fabrication method provided in an embodiment of this application;

[0031] Figure 2 This is a schematic diagram of a rate charging performance test provided in an embodiment of this application. Detailed Implementation

[0032] To make the technical solution and advantages of this application clearer, the embodiments of this application will be described in further detail below.

[0033] The terms "first," "second," "third," and "fourth," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0034] Figure 1 This is a flowchart of a solid-state battery fabrication method provided in an embodiment of this application. See also... Figure 1 The preparation method includes:

[0035] Step 101: Mix at least one of oxide solid electrolyte and sulfide solid electrolyte, polymer solid electrolyte and positive electrode material in a first ratio to obtain positive electrode slurry.

[0036] In the embodiments of this application, the oxide solid electrolyte includes at least one of perovskite oxide solid electrolyte, sodium superion conductor oxide solid electrolyte, lithium superion conductor oxide solid electrolyte, and garnet oxide solid electrolyte;

[0037] Sulfide solid electrolytes include at least one of perovskite-type sulfide solid electrolytes, sodium superionic conductor-type sulfide solid electrolytes, lithium superionic conductor-type sulfide solid electrolytes, and garnet-type sulfide solid electrolytes;

[0038] Polymer solid electrolytes include at least one of polyethylene oxide (PEO), polyacrylonitrile (PAN), polyvinylidene fluoride (PVDF), polymethyl methacrylate (PMMA), polypropylene oxide (PPO), polyvinylidene chloride (PVDC), and single-ion polymer solid electrolytes.

[0039] The cathode material includes one or two of lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate, and lithium manganese iron phosphate, without specific limitations.

[0040] In this step, at a temperature of 40℃ to 200℃, at least one of oxide solid electrolyte and sulfide solid electrolyte, polymer solid electrolyte and positive electrode material are mixed in a first ratio and stirred evenly to obtain positive electrode slurry.

[0041] For example, an oxide solid electrolyte, a polymer solid electrolyte, and a cathode material are mixed in a first ratio, or a sulfide solid electrolyte, a polymer solid electrolyte, and a cathode material are mixed in a first ratio, or an oxide solid electrolyte, a sulfide solid electrolyte, a polymer solid electrolyte, and a cathode material are mixed in a first ratio.

[0042] The first ratio is: 0 < at least one of oxide solid electrolyte and sulfide solid electrolyte ≤ 30%, 0 < polymer solid electrolyte ≤ 30%, 60% ≤ cathode material < 100%, and the sum of the mass of at least one of oxide solid electrolyte and sulfide solid electrolyte, polymer solid electrolyte and cathode material is 100%.

[0043] For example, the proportion of at least one of oxide solid electrolyte and sulfide solid electrolyte is 5%, the proportion of polymer solid electrolyte is 5%, and the proportion of cathode material is 90%; or, the proportion of at least one of oxide solid electrolyte and sulfide solid electrolyte is 5%, the proportion of polymer solid electrolyte is 10%, and the proportion of cathode material is 85%; or, the proportion of at least one of oxide solid electrolyte and sulfide solid electrolyte is 10%, the proportion of polymer solid electrolyte is 10%, and the proportion of cathode material is 80%.

[0044] When both oxide solid electrolytes and sulfide solid electrolytes are used, the mass ratio between the oxide solid electrolyte and the sulfide solid electrolyte can be set and changed as needed. For example, the mass ratio of oxide solid electrolyte to sulfide solid electrolyte can be 1:1, 2:1, 3:1, 4:1 or other ratios, and there are no specific limitations on this.

[0045] The temperature can be 50℃, 70℃, 90℃, 110℃, 130℃, 150℃ or 200℃, and the stirring speed is greater than 5m / s, for example, the stirring speed is 6m / s, 7m / s or 8m / s, and there is no specific limitation.

[0046] Step 102: Mix at least one of oxide solid electrolyte and sulfide solid electrolyte, polymer solid electrolyte and negative electrode material in a second ratio to obtain negative electrode slurry.

[0047] In this step, at a temperature of 40℃ to 200℃, at least one of oxide solid electrolyte and sulfide solid electrolyte, polymer solid electrolyte and negative electrode material are mixed in a second ratio and stirred evenly to obtain negative electrode slurry.

[0048] The negative electrode material includes one or two of graphite, silicon oxide, silicon, lithium, graphene, hard carbon, and soft carbon, without specific limitations. The stirring speed is greater than 5 m / s, for example, 6 m / s, 7 m / s, or 8 m / s, without specific limitations.

[0049] It should be noted that both steps 101 and 102 include at least one of oxide solid electrolyte and sulfide solid electrolyte. The at least one of oxide solid electrolyte and sulfide solid electrolyte used in step 101 may be the same as or different from the at least one of oxide solid electrolyte and sulfide solid electrolyte used in step 102.

[0050] In one possible implementation, at least one of the oxide solid electrolyte and the sulfide solid electrolyte used in step 101 is the same as at least one of the oxide solid electrolyte and the sulfide solid electrolyte used in step 102.

[0051] For example, if step 101 involves mixing an oxide solid electrolyte, a polymer solid electrolyte, and a positive electrode material, then step 102 also involves mixing the oxide solid electrolyte, the polymer solid electrolyte, and a negative electrode material. Similarly, if step 101 involves mixing a sulfide solid electrolyte, a polymer solid electrolyte, and a positive electrode material, then step 102 also involves mixing the sulfide solid electrolyte, the polymer solid electrolyte, and a negative electrode material. Again, if step 101 involves mixing an oxide solid electrolyte, a sulfide solid electrolyte, a polymer solid electrolyte, and a positive electrode material, then step 102 also involves mixing the oxide solid electrolyte, the sulfide solid electrolyte, the polymer solid electrolyte, and a negative electrode material.

[0052] In another possible implementation, at least one of the oxide solid electrolyte and the sulfide solid electrolyte used in step 101 is different from at least one of the oxide solid electrolyte and the sulfide solid electrolyte used in step 102.

[0053] For example, step 101 involves mixing the oxide solid electrolyte, the polymer solid electrolyte, and the positive electrode material, while step 102 involves mixing the oxide solid electrolyte, the sulfide solid electrolyte, the polymer solid electrolyte, and the negative electrode material. Again, step 101 involves mixing the oxide solid electrolyte, the polymer solid electrolyte, and the positive electrode material, while step 102 involves mixing the sulfide solid electrolyte, the polymer solid electrolyte, and the negative electrode material. Again, step 101 involves mixing the oxide solid electrolyte, the sulfide solid electrolyte, the polymer solid electrolyte, and the positive electrode material, while step 102 involves mixing the sulfide solid electrolyte, the polymer solid electrolyte, and the negative electrode material.

[0054] In this embodiment of the application, only one of the oxide solid electrolyte and sulfide solid electrolyte used in step 101 is the same as one of the oxide solid electrolyte and sulfide solid electrolyte used in step 102.

[0055] Furthermore, the second ratio and the first ratio can be the same or different, and there is no specific limitation on this. In the embodiments of this application, only the example of the second ratio and the first ratio being the same is used for illustration.

[0056] Step 103: Mix at least one of the oxide solid electrolyte and the sulfide solid electrolyte with the polymer solid electrolyte in a third ratio to obtain a composite electrolyte slurry.

[0057] This step can be as follows: at a temperature of 40℃~200℃, at least one of oxide solid electrolyte and sulfide solid electrolyte and polymer solid electrolyte in a molten state are mixed in a third ratio and stirred evenly to obtain composite electrolyte slurry.

[0058] Among them, oxide solid electrolyte and polymer solid electrolyte can be mixed in a third ratio, or sulfide solid electrolyte and polymer solid electrolyte can be mixed in a third ratio, or oxide solid electrolyte, sulfide solid electrolyte and polymer solid electrolyte can be mixed in a third ratio.

[0059] The third ratio is: 0 < at least one of oxide solid electrolyte and sulfide solid electrolyte < 100%, 0 < polymer solid electrolyte < 100%, and the sum of the mass of at least one of oxide solid electrolyte and sulfide solid electrolyte and polymer solid electrolyte is 100%.

[0060] For example, the proportion of oxide solid electrolyte is 50% and the proportion of polymer solid electrolyte is 50%; or, the proportion of oxide solid electrolyte is 10% and the proportion of polymer solid electrolyte is 90%; or the proportion of oxide solid electrolyte is 40%, the proportion of sulfide solid electrolyte is 50% and the proportion of polymer solid electrolyte is 10%, without specific limitations.

[0061] It should be noted that there is no specific order among steps 101, 102, and 103. During preparation, step 101 can be performed first, followed by steps 102 and 103 in sequence, or step 102 can be performed first, followed by steps 101 and 103 in sequence, or step 103 can be performed first, followed by steps 101 and 102 in sequence. There is no specific limitation on this order.

[0062] Step 104: Prepare positive electrode sheets and negative electrode sheets using positive electrode slurry, negative electrode slurry and composite electrolyte slurry.

[0063] This step can be implemented in any of the following ways.

[0064] The first method involves coating the positive electrode slurry onto the positive electrode current collector to obtain the positive electrode sheet; and coating the negative electrode slurry and the composite electrolyte slurry onto the negative electrode current collector to obtain the negative electrode sheet.

[0065] In this implementation, the negative electrode slurry and the composite electrolyte slurry can be coated onto the negative electrode current collector using a double-layer coating method. Of course, other coating methods can also be used, and no specific limitation is made.

[0066] The second method involves coating the positive electrode slurry and the composite electrolyte slurry onto the positive electrode current collector to obtain the positive electrode sheet, and coating the negative electrode slurry onto the negative electrode current collector to obtain the negative electrode sheet.

[0067] In this implementation method, a double-layer coating method can be used to coat the positive electrode slurry and the composite electrolyte slurry onto the positive electrode current collector.

[0068] The third method involves coating the positive electrode slurry and the composite electrolyte slurry onto the positive electrode current collector to obtain the positive electrode sheet, and coating the negative electrode slurry and the composite electrolyte slurry onto the negative electrode current collector to obtain the negative electrode sheet.

[0069] In this implementation method, the positive electrode slurry and the composite electrolyte slurry can be coated on the positive electrode current collector using a double-layer coating method, and the negative electrode slurry and the composite electrolyte slurry can be coated on the negative electrode current collector using the same double-layer coating method.

[0070] For any of the above implementation methods, the coating thickness of the positive electrode slurry on the positive electrode sheet and the coating thickness of the negative electrode slurry on the negative electrode sheet are both less than 200 μm, and the coating thickness of the composite electrolyte slurry on any electrode sheet is less than 100 μm.

[0071] It should be noted that after the corresponding slurry and composite electrolyte slurry are coated onto the corresponding current collector, the current collector needs to be rolled, cut, and processed to finally obtain the corresponding electrode.

[0072] Both the positive and negative current collectors can be set and changed as needed. For example, the positive current collector can be aluminum foil and the negative current collector can be copper foil. Of course, other materials can also be used for the positive and negative current collectors, and there are no specific limitations on this.

[0073] Step 105: Heat-bond and age the positive and negative electrode sheets to obtain a solid-state battery.

[0074] The positive and negative electrode sheets are assembled by stacking or winding, and the temperature is 40℃~200℃, and the pressure is ≥10N / cm. 2 Under certain conditions, the positive and negative electrode sheets are thermally bonded together for a time of ≥30 minutes, and then aged to obtain a solid-state battery.

[0075] The temperature can be 50℃, 70℃, 90℃, 110℃, 130℃, 150℃, or 200℃, and the pressure can be 10N / cm. 2 12N / cm 2 15N / cm 2 18N / cm 2 Or 20N / cm 2 The heat application time can be 30 minutes, 40 minutes, 50 minutes, 60 minutes or 70 minutes, and there are no specific limitations on temperature, pressure or heat application time.

[0076] In addition, the aging method can be set and changed as needed, for example, leaving it at 45°C for 2 days, without any specific limitation.

[0077] In this embodiment, active materials (positive and negative electrode materials) and solid electrolyte are mixed and stirred uniformly at high temperature to ensure homogeneity of the solid electrolyte and active materials, forming an electrode sheet. A composite electrolyte is then coated onto the electrode sheet surface, and the solid-state battery is assembled using high-temperature, high-pressure heat-bonding technology. This method utilizes the flexibility of the polymer solid electrolyte, which can well adapt to electrode deformation and expansion, improving battery stability. Furthermore, the high-temperature, high-pressure heat-bonding method for solid-state battery fabrication ensures that the polymer solid electrolyte is in a viscoelastic state and interconnected. It also ensures that the positive and negative electrode materials are fully bonded to at least one of the oxide solid electrolyte and sulfide solid electrolytes, reducing internal stress between the solid electrolyte layer and the electrodes. This creates a pathway for ion transport at the positive and negative electrode interfaces, reducing interfacial impedance and enhancing ion transport capacity during charging and discharging, thereby improving the charging and discharging efficiency of the solid-state battery.

[0078] It should be noted that the preparation method provided in this application is compatible with existing lithium battery production processes, requiring only minor adjustments to existing equipment and processes. The production cost is low, and the solid electrolyte has good thermal stability, which can effectively reduce the risk of spontaneous combustion and explosion of the battery and improve battery safety.

[0079] The technical solution of this application will be described in detail below through specific embodiments.

[0080] Example 1

[0081] Step 1: Mix the oxide solid electrolyte, polymer solid electrolyte and positive electrode material in a ratio of 10%:10%:80% to obtain the positive electrode slurry.

[0082] Step 2: Mix the oxide solid electrolyte, polymer solid electrolyte and negative electrode material in a ratio of 10%:10%:80% to obtain the negative electrode slurry.

[0083] Step 3: Mix the oxide solid electrolyte and the polymer solid electrolyte in a ratio of 90%:10% to obtain a composite electrolyte slurry.

[0084] It should be noted that the temperature in steps 1 to 3 is >60℃ and the stirring speed is >5m / s.

[0085] Step 4: Coat the positive electrode slurry and composite electrolyte slurry onto the positive electrode current collector to obtain the positive electrode sheet, and coat the negative electrode slurry and composite electrolyte slurry onto the negative electrode current collector to obtain the negative electrode sheet.

[0086] Step 5: Assemble the positive and negative electrode plates at a temperature of 90℃ and a pressure of 15N / cm. 2Under certain conditions, the positive and negative electrode sheets are heat-bonded for 60 minutes, and after aging, a solid-state battery is obtained.

[0087] Example 2

[0088] Step 1: Mix the oxide solid electrolyte, polymer solid electrolyte and positive electrode material in a ratio of 10%:10%:80% to obtain the positive electrode slurry.

[0089] Step 2: Mix the oxide solid electrolyte, polymer solid electrolyte and negative electrode material in a ratio of 10%:10%:80% to obtain the negative electrode slurry.

[0090] Step 3: Mix the oxide solid electrolyte and the polymer solid electrolyte in a ratio of 90%:10% to obtain a composite electrolyte slurry.

[0091] It should be noted that the temperature in steps 1 to 3 is >60℃ and the stirring speed is >5m / s.

[0092] Step 4: Coat the positive electrode slurry onto the positive electrode current collector to obtain the positive electrode sheet, and coat the negative electrode slurry and composite electrolyte slurry onto the negative electrode current collector to obtain the negative electrode sheet.

[0093] Step 5: Assemble the positive and negative electrode plates at a temperature of 90℃ and a pressure of 15N / cm. 2 Under certain conditions, the positive and negative electrode sheets are heat-bonded for 60 minutes, and after aging, a solid-state battery is obtained.

[0094] Example 3

[0095] Step 1: Mix the oxide solid electrolyte, polymer solid electrolyte and positive electrode material in a ratio of 5%:5%:90% to obtain the positive electrode slurry.

[0096] Step 2: Mix the oxide solid electrolyte, polymer solid electrolyte and negative electrode material in a ratio of 5%:5%:90% to obtain the negative electrode slurry.

[0097] Step 3: Mix the oxide solid electrolyte and the polymer solid electrolyte in a ratio of 90%:10% to obtain a composite electrolyte slurry.

[0098] It should be noted that the temperature in steps 1 to 3 is >60℃ and the stirring speed is >5m / s.

[0099] Step 4: Coat the positive electrode slurry onto the positive electrode current collector to obtain the positive electrode sheet, and coat the negative electrode slurry and composite electrolyte slurry onto the negative electrode current collector to obtain the negative electrode sheet.

[0100] Step 5: Assemble the positive and negative electrode plates at a temperature of 90℃ and a pressure of 15N / cm. 2 Under certain conditions, the positive and negative electrode sheets are heat-bonded for 60 minutes, and after aging, a solid-state battery is obtained.

[0101] Example 4

[0102] Step 1: Mix oxide solid electrolyte, sulfide solid electrolyte, polymer solid electrolyte and positive electrode material in a ratio of 5%:5%:10%:80% to obtain positive electrode slurry.

[0103] Step 2: Mix oxide solid electrolyte, sulfide solid electrolyte, polymer solid electrolyte and negative electrode material in a ratio of 5%:5%:10%:80% to obtain negative electrode slurry.

[0104] Step 3: Mix oxide solid electrolyte, sulfide solid electrolyte and polymer solid electrolyte in a ratio of 40%, 50% and 10% to obtain composite electrolyte slurry.

[0105] It should be noted that the temperature in steps 1 to 3 is >60℃ and the stirring speed is >5m / s.

[0106] Step 4: Coat the positive electrode slurry onto the positive electrode current collector to obtain the positive electrode sheet, and coat the negative electrode slurry and composite electrolyte slurry onto the negative electrode current collector to obtain the negative electrode sheet.

[0107] Step 5: Assemble the positive and negative electrode plates at a temperature of 90℃ and a pressure of 15N / cm. 2 Under certain conditions, the positive and negative electrode sheets are heat-bonded for 60 minutes, and after aging, a solid-state battery is obtained.

[0108] Application Examples

[0109] This application example tested the rate charging performance of the solid-state batteries prepared in Examples 1 to 4 and the in-situ polymerized solid-state batteries in related technologies. The test results are shown in Table 1 and... Figure 2 The rate performance test conditions are as follows: at room temperature, nC is charged to the cutoff voltage, n = 1, 2, 3, 4, and the cutoff voltage is 4.2V.

[0110] Table 1

[0111]

[0112] According to Table 1 and Figure 2It can be seen that, compared to the in-situ polymerized solid-state battery, at the same charging rate, the capacity percentage of the solid-state batteries prepared in Examples 1 to 4 is greater than that of the in-situ polymerized solid-state battery. Therefore, the solid-state battery prepared in this application has better rate-charging performance and higher charge-discharge efficiency.

[0113] The above description is only for the purpose of enabling those skilled in the art to understand the technical solution of this application, and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for preparing a solid-state battery, characterized in that, The preparation method includes: A positive electrode slurry is obtained by mixing at least one of oxide solid electrolyte and sulfide solid electrolyte, a polymer solid electrolyte, and a positive electrode material in a first ratio, wherein the first ratio is: 0 < at least one of oxide solid electrolyte and sulfide solid electrolyte ≤ 30%, 0 < polymer solid electrolyte ≤ 30%, and 60% ≤ positive electrode material < 100%. At least one of the oxide solid electrolyte and the sulfide solid electrolyte, the polymer solid electrolyte and the negative electrode material are mixed in a second ratio to obtain a negative electrode slurry, wherein the second ratio is the same as the first ratio. At least one of the oxide solid electrolyte and the sulfide solid electrolyte is mixed with the polymer solid electrolyte in a third ratio to obtain a composite electrolyte slurry. The third ratio is: 0 < at least one of the oxide solid electrolyte and the sulfide solid electrolyte < 100%, 0 < the polymer solid electrolyte < 100%, and the sum of the mass of at least one of the oxide solid electrolyte and the sulfide solid electrolyte and the polymer solid electrolyte is 100%. A positive electrode sheet and a negative electrode sheet are prepared using the positive electrode slurry, the negative electrode slurry, and the composite electrolyte slurry. The positive electrode and the negative electrode are assembled by stacking or winding, under a temperature of 40℃~200℃ and a pressure ≥10N / cm. 2 Under certain conditions, the positive electrode and the negative electrode are thermally bonded together for a time of ≥30 minutes, and then aged to obtain a solid-state battery.

2. The preparation method according to claim 1, characterized in that, The preparation of positive and negative electrode sheets using the positive electrode slurry, the negative electrode slurry, and the composite electrolyte slurry includes: The positive electrode slurry is coated onto the positive electrode current collector to obtain the positive electrode sheet; the negative electrode slurry and the composite electrolyte slurry are coated onto the negative electrode current collector to obtain the negative electrode sheet; or... The positive electrode slurry and the composite electrolyte slurry are coated onto the positive electrode current collector to obtain the positive electrode sheet, and the negative electrode slurry is coated onto the negative electrode current collector to obtain the negative electrode sheet; or... The positive electrode slurry and the composite electrolyte slurry are coated onto the positive electrode current collector to obtain the positive electrode sheet, and the negative electrode slurry and the composite electrolyte slurry are coated onto the negative electrode current collector to obtain the negative electrode sheet.

3. The preparation method according to claim 2, characterized in that, The coating thickness of the positive electrode slurry on the positive electrode sheet and the coating thickness of the negative electrode slurry on the negative electrode sheet are both less than 200 μm, and the coating thickness of the composite electrolyte slurry on any electrode sheet is less than 100 μm.

4. The preparation method according to claim 2, characterized in that, The step of coating the negative electrode slurry and the composite electrolyte slurry onto the negative electrode current collector to obtain the negative electrode sheet includes: The negative electrode slurry and the composite electrolyte slurry are coated onto the negative electrode current collector using a double-layer coating method to obtain the negative electrode sheet.

5. The preparation method according to claim 1, characterized in that, The cathode material includes one or two of lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate, and lithium manganese iron phosphate. The negative electrode material includes one or two of graphite, silicon oxide, silicon, lithium, graphene, hard carbon, and soft carbon.

6. The preparation method according to claim 1, characterized in that, The oxide solid electrolyte includes at least one of perovskite oxide solid electrolyte, sodium superion conductor oxide solid electrolyte, lithium superion conductor oxide solid electrolyte, and garnet oxide solid electrolyte; The sulfide solid electrolyte includes at least one of perovskite-type sulfide solid electrolyte, sodium superion conductor-type sulfide solid electrolyte, lithium superion conductor-type sulfide solid electrolyte, and garnet-type sulfide solid electrolyte. The polymer solid electrolyte includes at least one of polyethylene oxide, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, polypropylene oxide, polyvinylidene chloride, and monoionic polymer solid electrolyte.

7. A solid-state battery, characterized in that, The solid-state battery is prepared using the preparation method described in any one of claims 1 to 6.

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