All-solid-state lithium ion battery containing oxyhalide composite solid electrolyte

Abstract

The invention discloses an all-solid-state lithium ion battery containing oxyhalide composite solid electrolyte. According to the oxyhalide composite solid electrolyte, the phosphate radical-containing lithium salt is introduced into the zirconium-based oxyhalide, so that the amorphization of the zirconium-based oxyhalide is promoted, the lithium ion transmission rate and the ionic conductivity are effectively improved, and the oxyhalide composite solid electrolyte has good variability and excellent high-voltage stability. The all-solid-state battery comprises a composite solid electrolyte plate, a composite positive plate and a composite negative plate, the composite positive plate comprises a binder formed by polymerizing (E)-4-methoxybutyl-2-olefine acid and (2-acrylamidoethyl) tert-butyl carbamate, the interface bonding force of the composite positive plate can be improved, and the stripping force and the ionic conductivity can be improved. The preparation process is simple, the raw material cost is low, and the potential of large-scale production is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of batteries, and in particular relates to an all-solid-state lithium-ion battery containing a halide oxide composite solid electrolyte. Background Art

[0002] Lithium-ion batteries, with their high energy density, lightweight design, and long lifespan, have been widely used in various fields, including mobile electronic devices, electric vehicles, and aerospace. However, current commercial liquid lithium-ion batteries also present a series of problems, including high-temperature decomposition of the electrolyte, gas production, and lithium dendrites piercing the separator. Furthermore, the flammable and explosive nature of organic electrolytes poses serious safety risks.

[0003] In recent years, all-solid-state lithium batteries using inorganic solid electrolytes have attracted widespread attention due to their high energy density and high safety. Among various inorganic solid electrolytes, halide-based solid electrolytes, especially chloride solid electrolytes, stand out due to their high ionic conductivity, high mechanical compliance and wide electrochemical window. Despite these advantages, achieving high performance and low cost of halide solid electrolytes remains a huge challenge. Many halide solid electrolytes with high ionic conductivity rely on expensive metal components such as Ta, La, In, etc., which limits their practicality. In contrast, zirconium-based halides have significant cost advantages due to the high abundance of Zr elements in the earth's crust. However, their relatively low ionic conductivity limits their widespread application in high-performance all-solid-state batteries.

[0004] Therefore, it is of great significance to use cheap raw materials and simple methods to prepare halide-based solid electrolytes and all-solid-state lithium-ion batteries with high room-temperature ionic conductivity and relative stability to high-potential positive electrodes. Summary of the Invention

[0005] The object of the present invention is to provide an all-solid-state lithium-ion battery containing a halide oxide composite solid electrolyte with a high lithium ion transmission rate.

[0006] The technical solutions adopted by the present invention to achieve the above-mentioned purpose are: An all-solid-state lithium-ion battery comprises a composite solid electrolyte, a composite positive electrode sheet and a composite negative electrode sheet, wherein the composite solid electrolyte comprises an amorphous phase component and a crystalline phase component.

[0007] Preferably, the amorphous phase component includes zirconium-based oxyhalide.

[0008] Preferably, the crystalline phase component comprises a lithium phosphate-containing salt.

[0009] Preferably, the composite solid electrolyte is expressed as xA-Li 2+2y ZrCl4O 1+y, wherein 0≤x≤0.3, 0≤y≤1, and A is a lithium salt containing phosphate.

[0010] Preferably, the lithium phosphate salt comprises Li 1.3 Al 0.3 Ti 1.7 (PO4)3、Li 1.5 Al 0.5 Ge 1.5 At least one of (PO4)3 and Li3PO4.

[0011] Preferably, the zirconium-based oxyhalide comprises a zirconium source compound, a lithium source compound, and an oxygen source compound.

[0012] Preferably, the zirconium source compound comprises ZrCl4.

[0013] Preferably, the lithium source compound includes at least one of LiCl, Li2O and Li2CO3.

[0014] Preferably, the oxygen source compound includes at least one of Li2O, Li2CO3 and LiOH.

[0015] Preferably, the composite positive electrode sheet includes a composite solid electrolyte and a binder.

[0016] Preferably, the polymerizable monomers of the binder include (E)-4-methoxybut-2-enoic acid and tert-butyl (2-acrylamidoethyl)carbamate.

[0017] Preferably, the mass ratio of tert-butyl (2-acrylamidoethyl)carbamate to (E)-4-methoxybut-2-enoic acid is 10-100:15-150.

[0018] (E)-4-methoxybut-2-enoic acid and (2-acrylamidoethyl)carbamic acid tert-butyl ester are used as the polymerization monomers of the binder to form a network structure through synergistic polymerization. Its flexible polymer skeleton works together with methoxy, amide, tert-butyl and other groups to enhance the cohesion of the binder and the adhesion of the interface through hydrogen bonding. On the other hand, it forms lithium-philic sites, promotes the transmission of lithium ions in the binder network, optimizes the interface compatibility between the electrode and the electrolyte, and thus synergistically improves the peel strength and ion conduction efficiency of the composite positive electrode sheet.

[0019] Preferably, the negative electrode sheet comprises a sulfide solid electrolyte.

[0020] Preferably, the sulfide solid state electrolyte includes Li6PS5Cl.

[0021] More preferably, the binder's polymerizable monomers include allyl 2,2,3,3,3-pentafluoropropyl ether, with the mass ratio of allyl 2,2,3,3,3-pentafluoropropyl ether to (E)-4-methoxybut-2-enoic acid being 10-100:15-150. Allyl 2,2,3,3,3-pentafluoropropyl ether, (E)-4-methoxybut-2-enoic acid, and tert-butyl (2-acrylamidoethyl)carbamate all participate in the polymerization reaction, acting synergistically. Cross-linking strengthens the three-dimensional skeleton structure of the binder network, enhancing the cohesion and mechanical toughness of the polymer matrix, thereby significantly increasing the peel strength of the composite positive electrode sheet. Fluorine atoms exert a strong electron-withdrawing effect, reducing the binder's surface energy, improving wettability with the electrode material, constructing ion transport channels, and enhancing the ionic conductivity of the all-solid-state battery.

[0022] The present invention also provides a method for preparing a composite solid electrolyte, comprising: Preparation of composite solid electrolyte: Under argon protection, lithium phosphate salt, zirconium source compound, lithium source compound and oxygen source compound are uniformly mixed, zirconium oxide balls are added, and ball milling is carried out at a speed of 550-700 rpm for 19-30 hours to obtain a composite solid electrolyte.

[0023] Preferably, the lithium phosphate salt comprises Li 1.3 Al 0.3 Ti 1.7 (PO4)3、Li 1.5 Al 0.5 Ge 1.5 At least one of (PO4)3 and Li3PO4.

[0024] Preferably, the zirconium source compound comprises ZrCl4.

[0025] Preferably, the lithium source compound includes at least one of LiCl, Li2O and Li2CO3.

[0026] Preferably, the oxygen source compound includes at least one of Li2O, Li2CO3 and LiOH.

[0027] Preferably, the molar ratio of the lithium phosphate salt to the zirconium source compound is 0.1-2:2-40.

[0028] Preferably, the molar ratio of the lithium source compound to the zirconium source compound is 6.5-65:5-50.

[0029] Preferably, the molar ratio of the oxygen source compound to the zirconium source compound is 6.5-65:5-50.

[0030] Preferably, the particle size of the zirconia balls is 5-15 mm.

[0031] Preferably, the mass molar ratio of the zirconium oxide balls to the zirconium source compound is 7-70 g:5-50 mmol.

[0032] The present invention also provides a method for preparing a binder, comprising: Preparation of the binder: Ammonium persulfate is dissolved in deionized water to obtain an ammonium persulfate solution; (E)-4-methoxybut-2-enoic acid, tert-butyl (2-acrylamidoethyl)carbamate, sodium lauryl sulfate, and OP-10 emulsifier are added to the deionized water, ultrasonic emulsification is performed, and the ammonium persulfate solution is added at 70-80° C. The mixture is reacted under a nitrogen atmosphere for 10-15 hours to obtain the binder.

[0033] Preferably, in the ammonium persulfate solution, the mass ratio of ammonium persulfate to deionized water is 6-60:150-1500.

[0034] Preferably, the mass ratio of (E)-4-methoxybut-2-enoic acid to deionized water is 15-150:225-2250.

[0035] Preferably, the mass ratio of tert-butyl (2-acrylamidoethyl)carbamate to (E)-4-methoxybut-2-enoic acid is 10-100:15-150.

[0036] Preferably, the mass ratio of sodium lauryl sulfate to (E)-4-methoxybut-2-enoic acid is 0.75-7.5:15-150.

[0037] Preferably, the mass ratio of OP-10 emulsifier to sodium lauryl sulfate is 0.3-4:0.75-7.5.

[0038] Preferably, the mass of the ammonium persulfate solution is measured by the mass of the ammonium persulfate therein, and the mass ratio of ammonium persulfate to (E)-4-methoxybut-2-enoic acid is 6-60:15-150.

[0039] More preferably, allyl 2,2,3,3,3-pentafluoropropyl ether may be added during the preparation of the binder.

[0040] More preferably, the mass ratio of allyl 2,2,3,3,3-pentafluoropropyl ether to (E)-4-methoxybut-2-enoic acid is 10-100:15-150.

[0041] The present invention also provides a method for preparing a composite positive electrode sheet, comprising: Preparation of composite positive electrode sheet: The positive electrode active material, conductive agent and composite solid electrolyte are uniformly mixed, ball milled at a speed of 80-120 rpm for 0.5-1.5 hours, and pressed into sheets at a pressure of 250-350 MPa to obtain a composite positive electrode sheet.

[0042] Preferably, the positive electrode active material comprises LiNi 0.83 Co 0.12 Mn 0.05 O2.

[0043] Preferably, the conductive agent comprises conductive carbon.

[0044] Preferably, the mass ratio of the positive electrode active material to the conductive agent is 35-350:0.5-5.

[0045] Preferably, the mass ratio of the composite solid electrolyte to the conductive agent is 15-150:0.5-5.

[0046] More preferably, a binder may be added during the preparation of the composite positive electrode sheet.

[0047] More preferably, the mass ratio of the binder to the conductive agent is 2.5-25:0.5-5.

[0048] The present invention also provides a method for preparing a composite negative electrode sheet, comprising: Preparation of composite negative electrode sheet: composite sulfide solid electrolyte is added to the surface of negative electrode active material, and pressed into sheet under a pressure of 300 MPa to obtain composite negative electrode sheet.

[0049] Preferably, the negative electrode active material comprises a lithium-indium alloy.

[0050] Preferably, in the lithium-indium alloy, the proportion of lithium atoms is 1-30 at %.

[0051] Preferably, the sulfide solid state electrolyte includes Li6PS5Cl.

[0052] Preferably, the mass ratio of the negative electrode active material to the sulfide solid electrolyte is 3.5-35:25-250.

[0053] The present invention also provides a method for preparing an all-solid-state lithium battery, comprising: Preparation of all-solid-state lithium battery: The composite solid electrolyte is pressed into a sheet under a pressure of 250-350 MPa to obtain an electrolyte sheet, the electrolyte sheet is evenly spread on the composite positive electrode sheet, Li6PS5Cl is coated on the surface of the electrolyte sheet, and the negative electrode sheet is laid, and pressed under a pressure of 250-350 MPa for 2-4 minutes to obtain an all-solid-state lithium battery.

[0054] Preferably, the mass ratio of the electrolyte sheet to the composite positive electrode sheet is 10-100:1-10.

[0055] Preferably, the mass ratio of Li6PS5Cl to the electrolyte sheet is 0.5-5:10-100.

[0056] Preferably, the mass ratio of the composite negative electrode sheet to the composite positive electrode sheet is 1-10:1-10.

[0057] The present invention utilizes a phosphate-containing lithium salt and a zirconium-based oxyhalide solid electrolyte, along with a binder formed by polymerization of (E)-4-methoxybut-2-enoic acid and tert-butyl (2-acrylamidoethyl)carbamate. This advantageously achieves the following benefits: achieving a highly amorphous zirconium-based oxyhalide matrix, optimizing interfacial compatibility between the electrode and electrolyte, improving the ionic conductivity of the all-solid-state lithium-ion battery, and reducing overall raw material costs. Therefore, the present invention provides an all-solid-state lithium-ion battery containing an oxyhalide composite solid electrolyte with a high lithium ion transport rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 Schematic diagram of a scanning electron microscope image of the composite solid electrolyte prepared in Example 1.

[0059] Figure 2 Schematic diagram of a scanning electron microscope image of the composite solid electrolyte prepared in Example 2.

[0060] Figure 3 Schematic diagram of the X-ray diffraction pattern of the composite solid electrolyte.

[0061] Figure 4 Schematic diagram of the AC impedance spectrum of an all-solid-state lithium-ion battery.

[0062] Figure 5 Schematic diagram of the rate performance of all-solid-state lithium-ion batteries.

[0063] Figure 6 Schematic diagram of the long-cycle performance of all-solid-state lithium-ion batteries at 30°C.

[0064] Figure 7 Schematic diagram of the long-cycle performance of all-solid-state lithium-ion batteries at a cutoff voltage of 4.5 V. DETAILED DESCRIPTION

[0065] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0066] The following first describes the concepts involved in this application with reference to the accompanying drawings. It should be noted that the following description of each concept is intended only to make the content of this application easier to understand and does not limit the scope of protection of this application. At the same time, the embodiments and features in the embodiments of this application can be combined with each other unless there is a conflict. The following detailed description of this application will be made with reference to the accompanying drawings and in conjunction with the embodiments.

[0067] Example 1: Preparation of composite solid electrolyte: Under argon protection, Li 1.3 Al 0.3 Ti 1.7 (PO4)3, ZrCl4 and Li2O were uniformly mixed, zirconia balls were added, and ball milling was carried out at 600 rpm for 20 h to obtain a composite solid electrolyte. 1.3 Al 0.3 Ti 1.7 The molar ratio of (PO4)3 to ZrCl4 is 0.5:10, the molar ratio of Li2O to ZrCl4 is 13:10, the particle size of the zirconia balls is 10 mm, and the mass molar ratio of the zirconia balls to ZrCl4 is 35 g:10 mmol.

[0068] Preparation of composite positive electrode: LiNi 0.83 Co 0.12 Mn 0.05 O2, conductive carbon and composite solid electrolyte are evenly mixed, zirconium oxide balls are added, ball milled at 100 rpm for 1 hour, and pressed into sheets at a pressure of 300 MPa to obtain composite positive electrode sheets. 0.83 Co 0.12 Mn 0.05 The mass ratio of O2 to conductive carbon is 70:1, the mass ratio of the composite solid electrolyte to conductive carbon is 30:1, the particle size of the zirconia ball is 10 mm, and the mass ratio of the zirconia ball to conductive carbon is 1000:1.

[0069] Preparation of the composite negative electrode sheet: Li6PS5Cl is composited onto the surface of a lithium-indium alloy and pressed into a sheet at a pressure of 300 MPa. The lithium atoms in the lithium-indium alloy account for 1.5 at%; the mass ratio of the lithium-indium alloy to Li6PS5Cl is 7:50.

[0070] Preparation of an all-solid-state lithium battery: A composite solid electrolyte was pressed into a sheet at a pressure of 300 MPa to obtain an electrolyte sheet. This electrolyte sheet was evenly spread on a composite positive electrode sheet, followed by a composite negative electrode sheet, with the Li6PS5Cl side of the composite negative electrode sheet in contact with the electrolyte sheet. The battery was then pressed at a pressure of 300 MPa for 3 minutes to obtain an all-solid-state lithium battery. The mass ratio of the electrolyte sheet to the composite positive electrode sheet was 70:7, and the mass ratio of the composite negative electrode sheet to the composite positive electrode sheet was 57:7.

[0071] Example 2: Compared with Example 1, the only difference between this example and Example 1 is the preparation of the composite solid electrolyte.

[0072] Preparation of composite solid electrolyte: Under argon protection, Li 1.3 Al 0.3 Ti1.7 (PO4)3, ZrCl4 and Li2O were uniformly mixed, zirconia balls were added, and ball milling was carried out at 600 rpm for 20 h to obtain a composite solid electrolyte. 1.3 Al 0.3 Ti 1.7 The molar ratio of (PO4)3 to ZrCl4 is 1:10, the molar ratio of Li2O to ZrCl4 is 13:10, the particle size of the zirconia balls is 10 mm, and the mass molar ratio of the zirconia balls to ZrCl4 is 35 g:10 mmol.

[0073] Example 3: Compared with Example 1, the only difference between this example and Example 1 is the preparation of the composite solid electrolyte.

[0074] Preparation of composite solid electrolyte: Under argon protection, Li 1.3 Al 0.3 Ti 1.7 (PO4)3, ZrCl4 and Li2O were uniformly mixed, zirconia balls were added, and ball milling was carried out at 600 rpm for 20 h to obtain a composite solid electrolyte. 1.3 Al 0.3 Ti 1.7 The molar ratio of (PO4)3 to ZrCl4 is 1.5:10, the molar ratio of Li2O to ZrCl4 is 13:10, the particle size of the zirconia balls is 10 mm, and the mass molar ratio of the zirconia balls to ZrCl4 is 35 g:10 mmol.

[0075] Example 4: Compared with Example 1, the only difference between this example and Example 1 is the preparation of the composite solid electrolyte.

[0076] Preparation of composite solid electrolyte: Under argon protection, Li 1.3 Al 0.3 Ti 1.7 (PO4)3, ZrCl4 and Li2O were uniformly mixed, zirconia balls were added, and ball milling was carried out at 600 rpm for 20 h to obtain a composite solid electrolyte. 1.3 Al 0.3 Ti 1.7 The molar ratio of (PO4)3 to ZrCl4 is 2:10, the molar ratio of Li2O to ZrCl4 is 13:10, the particle size of the zirconia balls is 10 mm, and the mass molar ratio of the zirconia balls to ZrCl4 is 35 g:10 mmol.

[0077] Example 5: Compared with Example 1, the only difference between this example and Example 1 is the preparation of the composite solid electrolyte.

[0078] Preparation of the composite solid electrolyte: Under argon, Li₃PO₄, ZrCl₄, and Li₂O were uniformly mixed, zirconia balls were added, and the mixture was ball-milled at 600 rpm for 20 hours to obtain the composite solid electrolyte. The molar ratio of Li₃PO₄ to ZrCl₄ was 1:10, and the molar ratio of Li₂O to ZrCl₄ was 13:10. The particle size of the zirconia balls was 10 mm, and the mass molar ratio of the zirconia balls to ZrCl₄ was 35 g:10 mmol.

[0079] Example 6: Preparation of composite solid electrolyte: Under argon protection, Li 1.3 Al 0.3 Ti 1.7 (PO4)3, ZrCl4 and Li2O were uniformly mixed, zirconia balls were added, and ball milling was carried out at 600 rpm for 20 h to obtain a composite solid electrolyte. 1.3 Al 0.3 Ti 1.7 The molar ratio of (PO4)3 to ZrCl4 is 0.5:10, the molar ratio of Li2O to ZrCl4 is 13:10, the particle size of the zirconia balls is 10 mm, and the mass molar ratio of the zirconia balls to ZrCl4 is 35 g:10 mmol.

[0080] Preparation of the binder: Ammonium persulfate was dissolved in deionized water to obtain an ammonium persulfate solution; (E)-4-methoxybut-2-enoic acid, tert-butyl (2-acrylamidoethyl)carbamate, sodium lauryl sulfate, and OP-10 emulsifier were added to the deionized water and ultrasonically emulsified. The ammonium persulfate solution was added at 75°C and reacted under a nitrogen atmosphere for 12 hours to obtain the binder. In the ammonium persulfate solution, the mass ratio of ammonium persulfate to deionized water is 12:300; the mass ratio of (E)-4-methoxybut-2-enoic acid to deionized water is 30:450, the mass ratio of tert-butyl (2-acrylamidoethyl)carbamate to (E)-4-methoxybut-2-enoic acid is 20:30, the mass ratio of sodium dodecyl sulfate to (E)-4-methoxybut-2-enoic acid is 1.5:30, and the mass ratio of OP-10 emulsifier to sodium dodecyl sulfate is 0.75:1.5. The mass of the ammonium persulfate solution is measured by the mass of ammonium persulfate therein, and the mass ratio of ammonium persulfate to (E)-4-methoxybut-2-enoic acid is 12:30.

[0081] Preparation of composite positive electrode: LiNi 0.83 Co 0.12 Mn 0.05 O2, conductive carbon, composite solid electrolyte and binder are uniformly mixed, ball milled at 100 rpm for 1 hour, and pressed into sheets at a pressure of 300 MPa to obtain a composite positive electrode sheet. 0.83 Co0.12 Mn 0.05 The mass ratio of O2 to conductive carbon is 70:1, the mass ratio of composite solid electrolyte to conductive carbon is 30:1, and the mass ratio of binder to conductive carbon is 5:1.

[0082] Preparation of the composite negative electrode sheet: Li6PS5Cl is composited onto the surface of a lithium-indium alloy and pressed into a sheet at a pressure of 300 MPa. The lithium atoms in the lithium-indium alloy account for 1.5 at%; the mass ratio of the lithium-indium alloy to Li6PS5Cl is 7:50.

[0083] Preparation of an all-solid-state lithium battery: A composite solid electrolyte was pressed into a sheet at a pressure of 300 MPa to obtain an electrolyte sheet. This electrolyte sheet was evenly spread on a composite positive electrode sheet, followed by a composite negative electrode sheet, with the Li6PS5Cl side of the composite negative electrode sheet in contact with the electrolyte sheet. The battery was then pressed at a pressure of 300 MPa for 3 minutes to obtain an all-solid-state lithium battery. The mass ratio of the electrolyte sheet to the composite positive electrode sheet was 70:7, and the mass ratio of the composite negative electrode sheet to the composite positive electrode sheet was 57:7.

[0084] Example 7: Compared with Example 6, the only difference between this example is the preparation of the binder.

[0085] Preparation of the binder: Ammonium persulfate was dissolved in deionized water to obtain an ammonium persulfate solution; (E)-4-methoxybut-2-enoic acid, tert-butyl (2-acrylamidoethyl)carbamate, sodium lauryl sulfate, and OP-10 emulsifier were added to the deionized water and ultrasonically emulsified. The ammonium persulfate solution was added at 75°C and reacted under a nitrogen atmosphere for 12 hours to obtain the binder. In the ammonium persulfate solution, the mass ratio of ammonium persulfate to deionized water is 12:300; the mass ratio of (E)-4-methoxybut-2-enoic acid to deionized water is 30:450, the mass ratio of tert-butyl (2-acrylamidoethyl)carbamate to (E)-4-methoxybut-2-enoic acid is 40:30, the mass ratio of sodium dodecyl sulfate to (E)-4-methoxybut-2-enoic acid is 1.5:30, and the mass ratio of OP-10 emulsifier to sodium dodecyl sulfate is 0.75:1.5. The mass of the ammonium persulfate solution is measured by the mass of ammonium persulfate therein, and the mass ratio of ammonium persulfate to (E)-4-methoxybut-2-enoic acid is 12:30.

[0086] Example 8: Compared with Example 6, the only difference between this example and Example 6 is the preparation of the binder.

[0087] Preparation of the binder: Ammonium persulfate was dissolved in deionized water to obtain an ammonium persulfate solution; (E)-4-methoxybut-2-enoic acid, tert-butyl (2-acrylamidoethyl)carbamate, allyl 2,2,3,3,3-pentafluoropropyl ether, sodium lauryl sulfate, and OP-10 emulsifier were added to the deionized water and ultrasonic emulsification was performed. The ammonium persulfate solution was added at 75° C. and the mixture was reacted under a nitrogen atmosphere for 12 hours to obtain the binder. In the ammonium persulfate solution, the mass ratio of ammonium persulfate to deionized water is 12:300; the mass ratio of (E)-4-methoxybut-2-enoic acid to deionized water is 30:450, the mass ratio of tert-butyl (2-acrylamidoethyl)carbamate to (E)-4-methoxybut-2-enoic acid is 20:30, the mass ratio of allyl 2,2,3,3,3-pentafluoropropyl ether to (E)-4-methoxybut-2-enoic acid is 20:30, the mass ratio of sodium dodecyl sulfate to (E)-4-methoxybut-2-enoic acid is 1.5:30, and the mass ratio of OP-10 emulsifier to sodium dodecyl sulfate is 0.75:1.5. The mass of the ammonium persulfate solution is measured by the mass of ammonium persulfate therein, and the mass ratio of ammonium persulfate to (E)-4-methoxybut-2-enoic acid is 12:30.

[0088] Example 9: Compared with Example 6, the only difference between this example and Example 6 is the preparation of the binder.

[0089] Preparation of the binder: Ammonium persulfate was dissolved in deionized water to obtain an ammonium persulfate solution; (E)-4-methoxybut-2-enoic acid, tert-butyl (2-acrylamidoethyl)carbamate, allyl 2,2,3,3,3-pentafluoropropyl ether, sodium lauryl sulfate, and OP-10 emulsifier were added to the deionized water and ultrasonic emulsification was performed. The ammonium persulfate solution was added at 75° C. and the mixture was reacted under a nitrogen atmosphere for 12 hours to obtain the binder. In the ammonium persulfate solution, the mass ratio of ammonium persulfate to deionized water is 12:300; the mass ratio of (E)-4-methoxybut-2-enoic acid to deionized water is 30:450, the mass ratio of tert-butyl (2-acrylamidoethyl)carbamate to (E)-4-methoxybut-2-enoic acid is 20:30, the mass ratio of allyl 2,2,3,3,3-pentafluoropropyl ether to (E)-4-methoxybut-2-enoic acid is 40:30, the mass ratio of sodium dodecyl sulfate to (E)-4-methoxybut-2-enoic acid is 1.5:30, and the mass ratio of OP-10 emulsifier to sodium dodecyl sulfate is 0.75:1.5. The mass of the ammonium persulfate solution is measured by the mass of ammonium persulfate therein, and the mass ratio of ammonium persulfate to (E)-4-methoxybut-2-enoic acid is 12:30.

[0090] Comparative Example 1: Compared with Example 1, this comparative example differs only in the preparation of the composite solid electrolyte.

[0091] Preparation of the composite solid electrolyte: Under argon, ZrCl₄ and LiCl were uniformly mixed, zirconia balls were added, and the mixture was ball-milled at 600 rpm for 20 hours to obtain the composite solid electrolyte. The molar ratio of ZrCl₄ to LiCl was 10:20, the particle size of the zirconia balls was 10 mm, and the mass molar ratio of the zirconia balls to ZrCl₄ was 40 g:10 mmol.

[0092] Comparative Example 2: Compared with Example 1, this comparative example differs only in the preparation of the composite solid electrolyte.

[0093] Preparation of the composite solid electrolyte: Under argon, ZrCl₄ and LiCl were uniformly mixed, zirconia balls were added, and the mixture was ball-milled at 600 rpm for 20 hours to obtain the composite solid electrolyte. The molar ratio of ZrCl₄ to LiCl was 10:15, the particle size of the zirconia balls was 10 mm, and the mass molar ratio of the zirconia balls to ZrCl₄ was 40 g:10 mmol.

[0094] Comparative Example 3: This comparative example is different from Example 6 only in that tert-butyl (2-acrylamidoethyl)carbamate is not used in the preparation of the binder.

[0095] Comparative Example 4: This comparative example is different from Example 6 only in that (E)-4-methoxybut-2-enoic acid is not used in the preparation of the binder.

[0096] Comparative Example 5: This comparative example is different from Example 6 only in that tert-butyl (2-acrylamidoethyl)carbamate and (E)-4-methoxybut-2-enoic acid are not used in the preparation of the binder.

[0097] Experimental Example 1: Microstructural characterization of composite solid electrolyte.

[0098] Test sample: the composite solid electrolyte prepared in Example 1-2.

[0099] Test method: The surface of the composite solid electrolyte was treated with gold spraying, and the microscopic appearance of the composite solid electrolyte was observed using a scanning electron microscope.

[0100] The scanning electron microscope image of the composite solid electrolyte prepared in Example 1 is as follows: Figure 1 As shown, the scanning electron microscope image of the composite solid electrolyte prepared in Example 2 is as follows Figure 2 As shown, it shows that the composite solid electrolyte shown in the figure was successfully obtained. No obvious grain boundaries were observed in the composite solid electrolyte after tableting, and the electrolyte particles formed a continuous and dense surface, indicating that the composite solid electrolyte material prepared in Example 1-2 can achieve good interface contact in the all-solid-state battery, whether as a positive electrode filler or an electrolyte layer.

[0101] Experimental Example 2: X-ray diffraction test of composite solid electrolyte.

[0102] Test samples: composite solid electrolytes prepared in Examples 1-4 and Comparative Example 2.

[0103] Test method: The composite solid electrolyte was evenly loaded into the groove of the sample holder and compacted to ensure that the sample fits tightly to the sample holder. The scanning angle 2θ was set between 10°-90° and the scanning speed was set between 0.02°-0.05° / s. X-ray diffraction test was performed and the diffraction pattern was collected.

[0104] The X-ray diffraction patterns of the composite solid electrolytes prepared in Examples 1-4 and Comparative Example 2 are as follows: Figure 3 As shown, with Li 1.3 Al 0.3 Ti 1.7 As the amount of (PO4)3 added increases, the peaks corresponding to ZrCl4 and Li2O in Examples 1-4 gradually weaken, and the peaks corresponding to Li 1.3 Al 0.3 Ti 1.7 The characteristic peak of (PO4)3 gradually increases, indicating that Li 1.3 Al 0.3 Ti 1.7 The addition of (PO4)3 promotes the amorphization of ZrCl4 and Li2O matrices.

[0105] Test Example 3: Peel strength test of composite positive electrode sheet.

[0106] Test samples: composite positive electrode sheets prepared in various embodiments and comparative examples.

[0107] Test method: Cut the composite positive electrode sheet into strip samples with a width of 15 mm and a length of 40 mm. Use a universal material testing machine equipped with a 180° peeling fixture at a test speed of 15 mm / min to separate the electrode material surface from the aluminum foil current collector. Fix the material surface to the mobile fixture and the aluminum foil to the static fixture. Record the maximum tensile force during the peeling process and measure the average peel force of the composite positive electrode sheet.

[0108] The peel strength test results of the composite positive electrode sheet are shown in Table 1: Table 1 Peel strength test results of composite positive electrode sheets

[0109] Example 1-4 By adjusting Li 1.3 Al 0.3 Ti 1.7 The amount of (PO4)3 shows that the effect of the addition of lithium phosphate on the interfacial bonding strength is relatively stable within this range;1.3 Al 0.3 Ti 1.7 (PO4)3 is replaced by Li3PO4, and the peeling force is reduced compared with that of Example 1, indicating that there are differences in the compatibility of different lithium salt types with the system; Example 6 introduces a binder in the preparation of the composite positive electrode and optimizes the composition of the binder to improve the interaction between the components in the electrode, enhance the bonding strength of the electrode, and the peeling force is significantly improved compared with that of Example 1; Example 7 increases the amount of (2-acrylamidoethyl) tert-butyl carbamate, and the peeling force is further improved; Examples 8-9 introduce allyl 2,2,3,3,3-pentafluoropropyl ether and increase the ratio, which enhances the bonding network structure and achieves the highest peeling force; Comparative Example 1-2 did not use phosphate-containing lithium salts, and only ZrCl4 and LiCl were used to prepare the composite solid electrolyte. The peeling force was reduced compared with that of Example 1, confirming the importance of this component in maintaining the stability of the electrode structure; Comparative Example 3-4 lacked tert-butyl (2-acrylamidoethyl)carbamate or (E)-4-methoxybut-2-enoic acid in the binder, and the peeling force was reduced compared with that of Example 6; Comparative Example 5 lacked both tert-butyl (2-acrylamidoethyl)carbamate and (E)-4-methoxybut-2-enoic acid, and the peeling force was further reduced, indicating that the synergistic effect of the various components of the binder is indispensable for improving the interfacial bonding strength.

[0110] Test Example 4: Ionic conductivity test of all-solid-state lithium-ion battery.

[0111] Test samples: all-solid-state lithium-ion batteries prepared in various embodiments and comparative examples.

[0112] Test method: The ionic conductivity is measured by electrochemical impedance spectroscopy in air atmosphere, using Princeton PARSTAT MC electrochemical workstation connected to a computer, using the corresponding software for detection and data recording, the test frequency range is 1Hz-1000000Hz, and the disturbance voltage is 10mV. The ionic conductivity is calculated using the formula, where L is the electrolyte thickness, A is the surface area of the stainless steel column, and R is the impedance value.

[0113] The AC impedance spectrum of the all-solid-state lithium-ion battery prepared by the present invention is as follows: Figure 4 As shown, the ionic conductivity test results of the all-solid-state lithium-ion battery prepared by the present invention are shown in Table 2.

[0114] Table 2 Ionic conductivity test of all-solid-state lithium-ion battery

[0115] Example 1-2 By adjusting Li 1.3 Al 0.3 Ti 1.7The molar ratio of (PO4)3 to ZrCl4 indicates that the addition of lithium phosphate salts within this ratio range can promote the amorphization of zirconium-based oxyhalides, provide more continuous ion transport channels, and increase ion conductivity; Example 3-4 improves Li 1.3 Al 0.3 Ti 1.7 The amount of (PO4)3 used leads to an increase in the crystalline phase in the system, which reduces the ionic conductivity compared with Example 2. In Example 5, Li 1.3 Al 0.3 Ti 1.7 (PO4)3 is replaced by Li3PO4, which means that the composite system has a low degree of amorphization, or its interface compatibility with zirconium-based halide oxide is poor, resulting in increased ion transmission resistance; Example 6 introduces a binder in the preparation of the composite positive electrode sheet and optimizes the composition of the binder to improve the interface contact of the components inside the positive electrode sheet (active material, conductive carbon, composite solid electrolyte) and reduce the interface resistance of ion transmission; Example 7 increases the amount of (2-acrylamidoethyl) tert-butyl carbamate, and the ion conductivity is further improved; Examples 8-9 introduce the proportion of allyl 2,2,3,3,3-pentafluoropropyl ether, enhance the bonding network structure, improve the density of the electrode, promote the continuous transmission of ions in the electrode, improve the interface compatibility, and achieve the highest ion conductivity; Comparison In Example 1-2, no phosphate-containing lithium salt was used, and only ZrCl4 and LiCl were used to prepare a composite solid electrolyte. The ionic conductivity was lower than that in Example 1. Due to the lack of the promoting effect of the phosphate-containing lithium salt, the zirconium-based halide oxide was difficult to form an amorphous structure, the grain boundary resistance was large, and the ion transmission efficiency was low. In Comparative Example 3-4, the ionic conductivity was lower than that in Example 6 due to the lack of (2-acrylamidoethyl)carbamic acid tert-butyl ester or (E)-4-methoxybut-2-enoic acid in the binder. Comparative Example 5 lacked both (2-acrylamidoethyl)carbamic acid tert-butyl ester and (E)-4-methoxybut-2-enoic acid, resulting in a loose internal structure of the electrode, poor interface contact, and interrupted ion transmission path, thereby reducing the conductivity. The ionic conductivity was further reduced compared with Comparative Example 3.

[0116] Test Example 5: Battery cycle stability test of all-solid-state lithium-ion battery.

[0117] Test sample: the all-solid-state lithium-ion battery prepared in Example 2.

[0118] Test method: The long cycle performance of all-solid-state lithium-ion batteries is tested using the LAND battery test system.

[0119] The rate performance of the all-solid-state lithium-ion battery prepared in Example 2 is as follows: Figure 5As shown, high capacity can still be maintained at a high rate of 3C, proving that the high ionic conductivity of the composite solid electrolyte ensures ion transport inside the battery and achieves excellent high-rate performance.

[0120] The long cycle performance of the all-solid-state lithium-ion battery prepared in Example 2 at 30°C is as follows: Figure 6 As shown, the high capacity is maintained at a current of 1C, and the capacity retention rate after 700 cycles is 88.6%, thanks to Li 1.3 Al 0.3 Ti 1.7 (PO4)3 has excellent high-pressure stability.

[0121] The long cycle performance of the all-solid-state lithium-ion battery prepared in Example 2 at a cut-off voltage of 4.5V is as follows: Figure 7 As shown in the figure, the capacity retention rate is 80.4%, and the stable operation shows that the prepared composite solid electrolyte effectively improves the overall energy density of the battery.

[0122] The embodiments and / or implementation methods described above are only used to illustrate the preferred embodiments and / or implementation methods for realizing the technology of the present invention, and do not impose any form of limitation on the implementation methods of the technology of the present invention. Any person skilled in the art may make slight changes or modifications to other equivalent embodiments without departing from the scope of the technical means disclosed in the content of the present invention, but they should still be regarded as technologies or embodiments that are essentially the same as the present invention.

[0123] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. The above is only the preferred implementation method of this application. It should be pointed out that due to the limitations of textual expression, there are objectively infinite specific structures. For ordinary technicians in this technical field, without departing from the principles of this application, they can also make several improvements, modifications or changes, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the inventive concept and technical solution to other occasions without improvement, should be regarded as the scope of protection of this application.

Claims

1. An all-solid-state lithium-ion battery, comprising a composite solid electrolyte, a composite positive electrode sheet, and a composite negative electrode sheet, wherein the composite solid electrolyte comprises an amorphous phase component and a crystalline phase component, the amorphous phase component comprises a zirconium-based oxyhalide, and the crystalline phase component comprises a phosphate-containing lithium salt.

2. The all-solid-state lithium-ion battery according to claim 1, characterized in that: The composite solid electrolyte is expressed as xA-Li 2+2y ZrCl4O 1+y , wherein 0≤x≤0.3, 0≤y≤1, and A is a lithium salt containing phosphate.

3. The all-solid-state lithium-ion battery according to claim 1, characterized in that: The phosphate-containing lithium salt includes Li 1.3 Al 0.3 Ti 1.7 (PO4)3、Li 1.5 Al 0.5 Ge 1.5 At least one of (PO4)3 and Li3PO4.

4. The all-solid-state lithium-ion battery according to claim 1, characterized in that: The zirconium-based oxyhalide includes a zirconium source compound, a lithium source compound and an oxygen source compound, and the zirconium source compound includes ZrCl4.

5. The all-solid-state lithium-ion battery according to claim 4, characterized in that: The lithium source compound includes at least one of LiCl, Li2O and Li2CO3.

6. The all-solid-state lithium-ion battery according to claim 4, characterized in that: The oxygen source compound includes at least one of Li2O, Li2CO3 and LiOH.

7. The all-solid-state lithium-ion battery according to claim 1, characterized in that: The composite positive electrode sheet includes a composite solid electrolyte and a binder.

8. The all-solid-state lithium-ion battery according to claim 7, characterized in that: The polymerizable monomers of the binder include (E)-4-methoxybut-2-enoic acid and tert-butyl (2-acrylamidoethyl)carbamate.

9. The all-solid-state lithium-ion battery according to claim 8, characterized in that: The mass ratio of the tert-butyl (2-acrylamidoethyl)carbamate to the (E)-4-methoxybut-2-enoic acid is 10-100:15-150.

10. The all-solid-state lithium-ion battery according to claim 1, characterized in that: The negative electrode sheet includes a sulfide solid electrolyte, and the sulfide solid electrolyte includes Li6PS5Cl.

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