Electrode material coated with solid electrolyte as well as preparation method and application of electrode material

Abstract

The invention discloses an electrode material coated with a solid electrolyte and a preparation method and application of the electrode material, the electrode material is a positive electrode material or a negative electrode material, the solid electrolyte is dispersed on the grain boundary and the surface of the electrode material, and the chemical formula of the solid electrolyte is Li < 7-x > La < 3-y > Zr < 2-z > M < alpha > O < 12-beta > D < delta >, wherein M is at least one cation doping element, and D is at least one anion doping element; 0 < = x < = 2, 0 < = y < = 1.5, 0 < = z < = 1.5, 0 < alpha < 3, 0 < = beta < = 1.5, and 0 < = delta < = 1. The connection effect of the solid electrolyte, the positive electrode material and the negative electrode material is improved, and the preparation method can meet the compounding requirements of different positive electrode materials and negative electrode materials on the solid electrolyte and is suitable for large-scale application.

Description

Technical Field

[0001] The present invention belongs to the technical field of solid-state batteries, and particularly relates to an electrode material coated with a solid electrolyte, a preparation method thereof, and an application thereof. Background Art

[0002] Solid electrolytes are an important type of material and are widely used in various battery fields, such as all-solid-state lithium metal or lithium-ion batteries, semi-solid-state lithium-ion batteries, lithium-air batteries, etc. With the upgrade of lithium-ion batteries towards high energy density and high safety, all-solid-state batteries have become a key research direction due to the use of non-flammable solid electrolytes to replace liquid electrolytes. However, the solid-solid interface problems (such as poor contact and side reactions) between solid electrolytes and electrode active materials seriously restrict battery performance. Coating the surface of electrode active materials with solid electrolytes can inhibit interface side reactions through physical isolation, and at the same time optimize the ion transport path as an artificial interface layer. However, the existing solid electrolyte coatings only exist on the surface of electrode materials, have general ion conduction ability and poor cycle stability, cannot meet the composite requirements of different cathode materials and anode materials for solid electrolytes, and are not conducive to industrial promotion. Summary of the Invention

[0003] (I) Objects of the Invention

[0004] The object of the present invention is to provide an electrode material coated with a solid electrolyte, a preparation method thereof, and an application thereof. In the electrode material coated with a solid electrolyte prepared by the present invention, the solid electrolyte is distributed at the grain boundaries and on the surface of the cathode material or anode material, improving the connection effect between the solid electrolyte and the cathode material and anode material. The used preparation method can meet the composite requirements of different cathode materials and anode materials for solid electrolytes and is suitable for large-scale application.

[0005] (II) Technical Solutions

[0006] To solve the above problems, a first aspect of the present invention provides an electrode material coated with a solid electrolyte. The electrode material is a cathode material or an anode material, and the solid electrolyte is distributed at the grain boundaries and on the surface of the electrode material. The chemical formula of the solid electrolyte is Li 7-x La 3-y Zr 2-z M α O 12-β D δ ; wherein, M includes at least one cation doping element, D includes at least one anion doping element; and 0 ≤ x ≤ 2, 0 ≤ y ≤ 1.5, 0 ≤ z ≤ 1.5, 0 < α < 3, 0 ≤ β ≤ 1.5, 0 ≤ δ ≤ 1.

[0007] Further, the positive electrode material includes at least one of lithium cobaltate, lithium manganate, lithium iron phosphate, lithium-rich manganese-based solid solution, lithium nickel cobalt manganate, and lithium nickel cobalt aluminate.

[0008] Further, the negative electrode material includes at least one of graphite, soft carbon, hard carbon, lithium titanate, silicon, silicon carbide, and silicon oxide.

[0009] Further, M includes at least one of cations Na, K, Rb, Cs, Mg, Ca, Sr, Ba, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, B, Al, Ga, In, Si, Ge, Sn, Sb, Bi, Se, Te, Nb, Mo, Hf, Ta, W, P, and rare earth elements, and the rare earth elements do not include La. Preferably, the doping element M includes at least one of cations Ti, V, Mn, Fe, Co, Ni, Cu, Zn, Al, Ga, In, Ge, Sn, Sb, Te, Nb, Mo, Ta, Ce, Pr, Nd, Sm, Eu, Gd, Yb, Sc, and Y. More preferably, the doping element M includes at least one of cations Mn, Fe, Co, Ni, Al, Ga, Nb, Ta, Ce, Pr, Nd, Sm, Gd, Yb, and Y.

[0010] Further, D includes at least one of anions F, Cl, Br, I, N, P, and S.

[0011] Further, the particle size of the electrode material coated with the solid electrolyte is 100 nm - 50 μm, the particle size of the solid electrolyte is 5 - 900 nm, and the particle size of the solid electrolyte is smaller than that of the electrode material.

[0012] Further, the solid electrolyte includes amorphous and crystalline garnet-type structures.

[0013] The second aspect of the present invention provides a method for preparing an electrode material coated with a solid electrolyte as described in any one of the above descriptions, including the following steps:

[0014] Mix and react the source compounds corresponding to each element with the electrode material according to the stoichiometric ratio required for the solid electrolyte to obtain a precursor, wherein the mixing methods include at least one of in-situ deposition, coating, ball milling, impregnation, and fusion;

[0015] After selectively drying and heat-treating the precursor, an electrode material coated with a solid electrolyte is obtained.

[0016] Further, the preparation of the precursor includes:

[0017] Mix the lanthanum source compound, zirconium source compound, M source or part of the M source compound with water, and prepare a mixed solution according to the stoichiometric ratio required for the solid electrolyte;

[0018] Add the mixed solution, electrode material, and alkaline substance into a reactor, carry out an in-situ deposition reaction, and the deposition is sequentially subjected to one or more steps of filtration, washing, and drying to obtain a deposition product;

[0019] Add a lithium source compound, the remaining M source compound, and optionally a D source compound to the deposition product, and mix evenly to obtain a precursor.

[0020] Further, the preparation of the precursor further includes:

[0021] Prepare and mix the lanthanum source compound, zirconium source compound, Li source compound, M source compound, and D source compound according to the stoichiometric ratio required for the solid electrolyte to obtain a mixture;

[0022] Mix the mixture with the electrode material to obtain a precursor;

[0023] Wherein the mixture includes any one of a solid mixture, a liquid mixture, or a solid-liquid mixture.

[0024] Further, the zirconium source compound includes at least one of zirconium oxychloride, zirconyl nitrate, zirconium sulfate, zirconium acetate, and zirconium citrate; the lanthanum source compound includes at least one of lanthanum chloride, lanthanum nitrate, lanthanum sulfate, lanthanum acetate, and lanthanum citrate.

[0025] Further, the M source compound includes at least one of M-containing nitrates, acetates, sulfates, citrates, and amino acid salts, molten salts, and aqueous solutions; the Li source compound includes at least one of Li-containing nitrates, acetates, sulfates, citrates, and amino acid salts, molten salts, and aqueous solutions; the D source compound includes at least one of nitrates, fluorides, chlorides, bromides, iodides, phosphates, sulfates, and sulfides.

[0026] Further, the alkaline substance is at least one of magnesium bicarbonate, urea, ammonium-containing alkaline substances, sodium-containing alkaline substances, and potassium-containing alkaline substances. The ammonium-containing alkaline substances include any one of ammonium hydroxides, ammonium carbonates, or ammonium bicarbonates. The sodium-containing alkaline substances include any one of sodium hydroxides, sodium carbonates, or sodium bicarbonates. The potassium-containing alkaline substances include any one of potassium hydroxides, potassium carbonates, or potassium bicarbonates. Preferably, it is at least one of sodium hydroxide, urea, ammonia water, and ammonium bicarbonate.

[0027] Further, in the in-situ deposition reaction, the pH value during the deposition process is controlled to be 4.5 - 14, preferably 5 - 10, the pH value at the deposition end point is controlled to be 8 - 13, preferably 9 - 11, and the deposition temperature is controlled to be 0 - 200 °C, preferably 10 - 80 °C.

[0028] Further, the drying temperature is 50 - 300 °C, and the drying time is 1 - 24 h.

[0029] Further, the heat treatment temperature is 400 - 900 °C, preferably 450 - 850 °C, the heat treatment time is 1 - 48 h, preferably 3 - 24 h. The heat treatment can be one-step or multi-step, and both the temperature and time are adjustable. The heat treatment process is a key step for the electrolyte to enter the grain boundaries of the electrode material. During the heat treatment process, metal ions will diffuse into both the lattice bulk phase and the grain boundaries simultaneously. According to the Harrison C-type kinetic mechanism, only grain boundary diffusion occurs at a specific temperature. Therefore, heat treatment at a specific temperature can enable the electrolyte-related elements to preferentially enter the matrix grain boundaries and form corresponding compounds with anions at the grain boundaries. In addition, solid electrolytes also exist on the surfaces and joints of the electrode material particles, comprehensively improving the lithium ion transport ability. Further, the heat treatment atmosphere is at least one of nitrogen, argon, oxygen, and air.

[0030] In addition, the third aspect of the present invention provides an application of the electrode material coated with a solid electrolyte as described in any one of the above descriptions or a preparation method of the electrode material coated with a solid electrolyte as described in any one of the above descriptions in all-solid-state lithium metal, all-solid-state lithium ion batteries, semi-solid-state lithium ion batteries, lithium-air batteries, all-solid-state sodium metal batteries, all-solid-state sodium ion batteries, and semi-solid-state sodium ion batteries.

[0031] (III) Beneficial effects

[0032] The above technical solutions of the present invention have the following beneficial technical effects: The present invention provides an electrode material coated with a solid electrolyte, its preparation method and application. The chemical formula of the solid electrolyte is Li 7-x La 3-y Zr 2-z M α O 12-β D δ; wherein, M is at least one cation doping element, D is at least one anion doping element, and 0 ≤ x ≤ 2, 0 ≤ y ≤ 1.5, 0 ≤ z ≤ 1.5, 0 < α < 3, 0 ≤ β ≤ 1.5, 0 ≤ δ ≤ 1. In the present invention, the solid electrolyte is located at the grain boundaries and surfaces of the cathode material and the anode material through a mixing method such as in-situ deposition, improving the connection effect between the solid electrolyte and the cathode material and the anode material; the solid electrolyte on the surfaces of the cathode material and the anode material exists in a continuous state, and the coexistence of the solid electrolyte at the grain boundaries and surfaces enhances the ion transport ability. The gaps between particles are also filled with the solid electrolyte, comprehensively improving the lithium ion transport ability and endowing the battery with excellent cycle stability and rate performance. The preparation method used has the advantages of simple process, low cost and strong universality, can meet the composite requirements of different cathode materials and anode materials for the solid electrolyte, and is suitable for large-scale application. The cathode material or anode material coated with the solid electrolyte obtained by the technical solution of the present invention can be used in fields such as all-solid-state lithium metal or lithium ion batteries, semi-solid-state lithium ion batteries, and lithium-air batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a scanning electron microscope image of the polycrystalline lithium nickel cobalt manganese oxide cathode material without the solid electrolyte coated in Example 1 of the present invention;

[0034] Figure 2 is a scanning electron microscope image of the polycrystalline lithium nickel cobalt manganese oxide cathode material coated with the solid electrolyte in Example 1 of the present invention;

[0035] Figure 3 is a scanning electron microscope image of the graphite anode material coated with the solid electrolyte prepared in Example 18 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] To make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the descriptions of well-known structures and technologies are omitted to avoid unnecessarily obscuring the concepts of the present invention.

[0037] Comparative Example 1

[0038] A coin cell was assembled with a polycrystalline lithium nickel cobalt manganese oxide cathode material, a Li 6.4 La3Zr2Ga 0.2 O 12 solid electrolyte sheet, and metallic lithium. After cycling 200 times at 1C, the capacity retention rate was 85.1%, and after cycling 200 times at 3C, the capacity retention rate was 76.3%.

[0039] Comparative Example 2

[0040] Lithium cobalt oxide cathode material, Li 6.5 La3Zr 1.5 Ta 0.5 O 12 The solid electrolyte membrane and metallic lithium were assembled into a coin-type half cell. After 200 cycles at 1C, the capacity retention rate was 84.2%, and after 200 cycles at 3C, the capacity retention rate was 77.4%.

[0041] Example 1

[0042] La(NO3)3, ZrO(NO3)2, and Ga(NO3)3 were prepared into a mixed solution with a total cation concentration of 1.5M in water according to the stoichiometric ratio. Under stirring conditions, the polycrystalline nickel cobalt manganese oxide cathode, the mixed solution, and 3.0M aqueous ammonia solution were added to the reactor at a uniform speed. The pH value during the deposition process was controlled at 7±0.2, the pH value at the deposition end point was 11, and the deposition temperature was controlled at 50°C for in-situ deposition reaction. Then, filtration, washing, and drying at 100°C for 18h were carried out. The dried product was mixed evenly with LiNO3 in the Li stoichiometric ratio to obtain a precursor. The precursor was dried at 100°C for 18h, and then heat-treated for 24h at 450°C for the first time. The heat treatment atmosphere is shown in Table 1. Then, it was heat-treated for 3h at 850°C for the second time to obtain graphite anode material coated with Li 6.4 La3Zr2Ga 0.2 O 12 solid electrolyte, and it was assembled with Li 6.4 La3Zr2Ga 0.2 O 12 solid electrolyte sheet and metallic lithium into a coin-type battery. After 200 cycles at 1C, the capacity retention rate was 93.3%, and after 200 cycles at 3C, the capacity retention rate was 90.1%. Figure 1 and Figure 2 are the scanning electron microscope images of the polycrystalline nickel cobalt manganese oxide cathode materials without and with coated solid electrolyte, respectively. By comparison, it can be seen that the surface of the cathode material without coated solid electrolyte ( Figure 1 ) is smooth and there are many grain boundaries. After coating ( Figure 2 ) there are granular solid electrolytes on the surface and at the grain boundaries of the cathode material. In-situ deposition is used to make the solid electrolyte exist at the electrode grain boundaries and surface, and the connection between the electrode and the electrolyte is better; the solid electrolyte exists in a continuous state on the surface, and the coexistence of the grain boundaries and the surface enhances the ability to conduct ions. The gaps between the particles are also filled, comprehensively improving the lithium ion transport ability.

[0043] Example 2

[0044] A mixed solution with a total cation concentration of 0.5 M is prepared from La(NO3)3 and ZrO(NO3)2 in stoichiometric ratio; under stirring conditions, the lithium cobalt oxide cathode, the mixed solution, and 3.0 M aqueous ammonia solution are added to the reactor at a uniform speed. The pH value during the deposition process is controlled at 9 ± 0.2, the final pH value is 10, the temperature is controlled at 50 °C, and an in-situ deposition reaction is carried out. Then, filtration and washing are carried out, and drying is carried out at 100 °C for 18 h; the dried product is mixed with Ta2O5 and LiNO3 in the stoichiometric ratio of Ta and Li to obtain a precursor. The precursor is dried at 100 °C for 18 h, then heat-treated at 500 °C for 18 h, and then heat-treated at 850 °C for 3 h to obtain the coated Li 6.5 La3Zr 1.5 Ta 0.5 O 12 The lithium cobalt oxide cathode material of the solid electrolyte, and Li 6.5 La3Zr 1.5 Ta 0.5 O 12 The solid electrolyte sheet and metallic lithium are assembled into a coin cell. After cycling 200 times at 1C, the capacity retention rate is 91.3%, and after cycling 200 times at 3C, the capacity retention rate is 87.8%.

[0045] Example 3

[0046] A mixed solution with a total cation concentration of 1.5 M is prepared from La(NO3)3 and ZrO(NO3)2 in stoichiometric ratio; under stirring conditions, the mixed solution, 3 M sodium hydroxide solution, and the polycrystalline lithium nickel cobalt manganese oxide cathode material are added to the reactor at a uniform speed. The pH during the deposition process is 10 - 14, the final pH value is 13, the temperature is controlled at 0 °C, and an in-situ deposition reaction is carried out. Then, filtration and washing are carried out, and drying is carried out at 300 °C for 1 h; the dried product is mixed with NbO(NO3)3 and LiNO3 compounds in the stoichiometric ratio of Nb and Li to obtain a precursor. The precursor is dried at 300 °C for 1 h, then heat-treated at 400 °C for 48 h, and then heat-treated at 750 °C for 10 h to obtain the coated Li 6.3 La3Zr 1.4 Nb 0.7 O 12 The lithium iron phosphate cathode material of the solid electrolyte, and Li 6.3 La3Zr 1.4 Nb 0.7 O 12 The solid electrolyte sheet and metallic lithium are assembled into a coin cell. After cycling 100 times at 1C, the capacity retention rate is 87.5%, and after cycling 200 times at 3C, the capacity retention rate is 82.8%.

[0047] Example 4

[0048] A mixed solution with a total cation concentration of 1.5 M is prepared from La(NO3)3 and ZrO(NO3)2 in stoichiometric ratio; under stirring conditions, the mixed solution, 3 M sodium hydroxide solution, and graphite negative electrode are added to the reactor at a uniform speed. The pH value during the deposition process is controlled at 4.5 - 9, the final pH value is 8, the temperature is controlled at 200 °C, and an in-situ deposition reaction is carried out. Then, filtration, washing are performed, and drying is carried out at 50 °C for 24 h. The dried product is mixed with Ce(NO3)3 and LiNO3 in the stoichiometric ratio of Ce and Li to obtain a precursor. The precursor is dried at 50 °C for 24 h, then heat-treated at 500 °C for 18 h, and further heat-treated at 900 °C for 1 h to obtain a coating of Li 6.8 La 2.8 Zr2Ce 0.2 O 12 Graphite negative electrode material of solid electrolyte, with Li 6.8 La 2.8 Zr2Ce 0.2 O 12 A solid electrolyte sheet and metallic lithium are assembled into a coin cell. After cycling 100 times at 1 C, the capacity retention rate is 86.5%, and after cycling 200 times at 3 C, the capacity retention rate is 81.2%.

[0049] Example 5

[0050] A mixed solution with a total cation concentration of 1.0 M is prepared from La2(SO4)3 and Zr(SO4)2 in stoichiometric ratio; under stirring conditions, the mixed solution, 4.0 M ammonia water solution, and lithium cobalt oxide positive electrode are added to the reactor at a uniform speed. The pH during the deposition process is 9 - 12, the final pH value of deposition is 9, the temperature is controlled at 50 °C, and an in-situ deposition reaction is carried out. Then, filtration, washing are performed, and drying is carried out at 120 °C for 15 h; The dried product is mixed with Ni(CH3COO)2, Al(CH3COO)3, and CH3COOLi in the stoichiometric ratio of Ni and Li to obtain a precursor. The precursor is dried at 120 °C for 15 h, then heat-treated at 420 °C for 30 h, and further heat-treated at 800 °C for 8 h to obtain a coating of Li 6.4 Al 0.2 La3Zr 1.95 Ni 0.05 O 11 Lithium cobalt oxide positive electrode of S solid electrolyte, with Li 6.4 Al 0.2 La3Zr 1.95 Ni 0.05 O 11 An S solid electrolyte sheet and metal are assembled into a coin cell. After cycling 100 times at 1 C, the capacity retention rate is 91.6%, and after cycling 200 times at 3 C, the capacity retention rate is 86.9%.

[0051] Example 6

[0052] Prepare a mixture with a total cation concentration of 0.5 M from La(CH3COO)3, Zr(CH3COO)4, Fe(NO3)3, and LiNO3 in stoichiometric ratio (this mixed material is a liquid-phase mixture); under stirring conditions, mix this mixture with the graphite negative electrode by impregnation to obtain a precursor; after drying the precursor at 100 °C for 18 h, conduct the first heat treatment at 550 °C for 15 h and the second heat treatment at 750 °C for 10 h to obtain a graphite negative electrode coated with Li 6.7 La3Zr2Fe 0.1 O 12 solid electrolyte, and assemble it with Li 6.7 La3Zr2Fe 0.1 O 12 solid electrolyte sheet and metallic lithium into a coin cell. After cycling 100 times at 1C, the capacity retention rate is 90.1%, and after cycling 200 times at 3C, the capacity retention rate is 86.2%.

[0053] Example 7

[0054] Mix the molten salts of La2O3, ZrO2, Co2O3, and Li2CO3 in stoichiometric ratio to obtain a mixture; under stirring conditions, fuse this mixture with the graphite negative electrode to obtain a precursor; heat-treat the precursor at 550 °C for 15 h and then at 700 °C for 12 h to obtain a graphite negative electrode material coated with Li7La3Zr 1.5 Co 0.5 O 12 solid electrolyte, and assemble it with Li7La3Zr 1.5 Co 0.5 O 12 solid electrolyte sheet and metallic lithium into a coin cell. After cycling 100 times at 1C, the capacity retention rate is 88.6%, and after cycling 200 times at 3C, the capacity retention rate is 84.2%.

[0055] Example 8

[0056] Mix La2O3, ZrO2, Pr2O3, and Li2CO3 in stoichiometric ratio by ball milling to obtain a mixture, ball mill-mix this mixture with the graphite negative electrode to obtain a precursor; dry the precursor at 80 °C for 20 h, then conduct the first heat treatment at 480 °C for 20 h and the second heat treatment at 880 °C for 2 h to obtain a graphite negative electrode coated with solid electrolyte Li7La 2.6 Zr2Pr 0.4 O 12 , and assemble it with Li7La 2.6 Zr2Pr 0.4 O 12The solid electrolyte sheet and metallic lithium are assembled into a button cell. After 100 cycles at 1C, the capacity retention rate is 85.9%, and after 200 cycles at 3C, the capacity retention rate is 81.1%.

[0057] Example 9

[0058] A mixed solution with a total cation concentration of 1.0 M is prepared from La(NO3)3 and ZrO(NO3)2 according to the stoichiometric ratio. Under stirring conditions, the silicon-carbon negative electrode, the mixed solution, and 3.0 M aqueous ammonia solution are added to the reactor at a uniform speed. The pH value during the deposition process is controlled at 8 ± 0.2, the final pH value is 9.5, the temperature is controlled at 50 °C, and the deposition reaction is carried out. Then, it is filtered, washed, and dried at 100 °C for 18 h. The dried product is mixed with Ni(NO3)2, Al(NO3)3, and LiNO3 in the stoichiometric ratio of Ni, Li to obtain a precursor. The precursor is dried at 90 °C for 19 h, then heat-treated for the first time at 500 °C for 18 h, and then heat-treated for the second time at 800 °C for 8 h to obtain the coated Li 6.4 Al 0.2 La3Zr 1.95 Ni 0.05 O 12 The silicon-carbon negative electrode of the solid electrolyte, and Li 6.4 Al 0.2 La3Zr 1.95 Ni 0.05 O 12 The solid electrolyte sheet and metallic lithium are assembled into a button cell. After 100 cycles at 1C, the capacity retention rate is 89.8%, and after 200 cycles at 3C, the capacity retention rate is 85.3%.

[0059] Examples 10 - 50 are treated in the same way as Examples 1 - 9, except that the chemical formula of the solid electrolyte, the alkaline substance, the drying mechanism, the heat treatment atmosphere, the electrode material, and the heat treatment process are different. The specific parameters and performances of Examples 1 - 50 are shown in Table 1. Among them Figure 3 is the scanning electron microscope image of the coated solid electrolyte graphite negative electrode material prepared in Example 18 of the present invention

[0060] The examples and comparative examples also include battery preparation, and the specific method is as follows:

[0061] Solid-state electrolyte-coated positive electrode: The solid-state electrolyte-coated positive electrode, acetylene black, and PVDF were weighed in an 8:1:1 mass ratio and dry-grinded for 6 minutes. An appropriate amount of N-methylpyrrolidone was then added and ground until viscous. The resulting mixture was evenly coated on 12μm aluminum foil and dried in a vacuum oven at 110°C for 6 hours. The dried electrode was punched into circular sheets with a 12mm aperture using a sheet press. These sheets were then assembled into CR2032 button cells in a glove box with the positive and negative electrode shells, solid-state electrolyte, and lithium metal anode. Charge and discharge tests (1C and 3C) were conducted on a battery testing system at 25°C with an operating voltage range of 2.0V-4.5V.

[0062] Solid-state electrolyte-coated anode: Lithium cobalt oxide, acetylene black, and PVDF were weighed in an 8:1:1 mass ratio and dry-grinded for 6 minutes. An appropriate amount of N-methylpyrrolidone was then added and ground until the mixture became viscous. The mixture was then evenly coated on 12μm aluminum foil and dried in a vacuum oven at 110°C for 6 hours. The dried electrode was punched into circular sheets with a 12mm aperture using a sheet press. These sheets were then assembled in a glove box with the positive and negative electrode shells, solid electrolyte, and anode coated with the solid electrolyte into a CR2032 button cell. Charge and discharge tests (1C and 3C) were conducted on a battery testing system at 25°C with an operating voltage range of 2.0V-4.5V.

[0063]

[0064]

[0065]

[0066]

[0067]

[0068]

[0069] It should be understood that the above-described specific embodiments of the present invention are merely illustrative or illustrative of the principles of the present invention and do not constitute limitations of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present invention should be included within the scope of protection of the present invention. In addition, the appended claims are intended to cover all variations and modifications that fall within the scope and metes and bounds of the appended claims, or equivalents thereof.

Claims

1. An electrode material coated with a solid electrolyte, characterized in that, The electrode material is a positive electrode material or a negative electrode material, and the chemical formula of the solid electrolyte is Li 7-x La 3-y Zr 2-z M α O 12-β D δ ; Wherein, M is at least one cation doping element, and D is at least one anion doping element; and 0 ≤ x ≤ 2, 0 ≤ y ≤ 1.5, 0 ≤ z ≤ 1.5, 0 < α < 3, 0 ≤ β ≤ 1.5, 0 ≤ δ ≤ 1.

2. The electrode material coated with a solid electrolyte according to claim 1, wherein The solid electrolyte is distributed at the grain boundaries and surfaces of the electrode material.

3. The electrode material coated with a solid electrolyte according to claim 1 or 2, characterized in that, The positive electrode material includes at least one of lithium cobalt oxide, lithium manganese oxide, lithium iron phosphate, lithium-rich manganese-based solid solution, lithium nickel cobalt manganese oxide, and lithium nickel cobalt aluminum oxide.

4. The electrode material coated with a solid electrolyte according to claim 3, characterized in that, The negative electrode material includes at least one of graphite, soft carbon, hard carbon, lithium titanate, silicon, silicon carbide, and silicon oxide.

5. The electrode material coated with a solid electrolyte according to claim 1, 2 or 4, characterized in that: The M includes at least one of cations Ti, V, Mn, Fe, Co, Ni, Cu, Zn, Al, Ga, In, Ge, Sn, Sb, Te, Nb, Mo, Ta, Ce, Pr, Nd, Sm, Eu, Gd, Yb, Sc, and Y.

6. The electrode material coated with a solid electrolyte according to claim 5, characterized in that, The D includes at least one of anions F, Cl, Br, I, N, P, and S.

7. The electrode material coated with a solid electrolyte according to claim 1, 2, 4 or 6, characterized in that, The particle size of the electrode material coated with the solid electrolyte is 100 nm - 50 μm.

8. The electrode material coated with a solid electrolyte according to claim 7, characterized in that, The solid electrolyte includes amorphous and crystalline garnet-type structures.

9. A method for preparing an electrode material coated with a solid electrolyte according to any one of claims 1 to 8, characterized in that, It includes the following steps: According to the stoichiometric ratio required for the solid electrolyte, the source compounds corresponding to each element are mixed with the electrode material and reacted to obtain a precursor. Among them, the mixing methods include at least one of in-situ deposition, coating, ball milling, impregnation, and fusion; After selectively drying and heat-treating the precursor, an electrode material coated with a solid electrolyte is obtained.

10. The preparation method of the electrode material coated with a solid electrolyte according to claim 9, characterized in that, The preparation of the precursor includes: Mix a lanthanum source compound, a zirconium source compound, an M source or a partial M source compound, and water, and prepare a mixed solution according to the stoichiometric ratio required for the solid electrolyte; Add the mixed solution, the electrode material, and an alkaline substance into a reactor for in-situ deposition reaction, and the deposition is sequentially subjected to one or more steps of filtration, washing, and drying to obtain a deposition product; Add a lithium source compound, the remaining M source compound, and optionally a D source compound to the deposition product, and after mixing evenly, a precursor is obtained.

11. The method for preparing an electrode material coated with a solid electrolyte according to claim 9, wherein: The preparation of the precursor further includes: Mix a lanthanum source compound, a zirconium source compound, a Li source compound, an M source compound, and a D source compound according to the stoichiometric ratio required for the solid electrolyte to obtain a mixture; Mix the mixture with the electrode material to obtain a precursor; Wherein the mixture is any one of a solid mixture, a liquid mixture, and a solid-liquid mixture.

12. The preparation method of the electrode material coated with a solid electrolyte according to claim 10, characterized in that, The zirconium source compound includes at least one of zirconium oxychloride, zirconium oxynitrate, zirconium sulfate, zirconium acetate, and zirconium citrate; the lanthanum source compound includes at least one of lanthanum chloride, lanthanum nitrate, lanthanum sulfate, lanthanum acetate, and lanthanum citrate.

13. The preparation method of the electrode material coated with a solid electrolyte according to claim 10, characterized in that, The M source compound includes at least one of nitrates, acetates, sulfates, citrates, and amino acid salts, molten salts, and aqueous solutions containing M; the Li source compound includes at least one of nitrates, acetates, sulfates, citrates, and amino acid salts, molten salts, and aqueous solutions containing Li; the D source compound includes at least one of nitrates, fluorides, chlorides, bromides, iodides, phosphates, sulfates, and sulfides.

14. The method for preparing an electrode material coated with a solid electrolyte according to claim 10, wherein: The alkaline substance is at least one of magnesium bicarbonate, urea, ammonium-containing alkaline substances, sodium-containing alkaline substances and potassium-containing alkaline substances.

15. The method for preparing the electrode material of the solid electrolyte according to claim 10, wherein, In the in-situ deposition reaction, the pH value during the deposition process is controlled to be 4.5-14, the pH value at the deposition endpoint is controlled to be 8-13, and the deposition temperature is controlled to be 0-200°C.

16. The preparation method of the electrode material coated with a solid electrolyte according to claim 9 or 10, characterized in that, The drying temperature is 50-300° C., and the drying time is 1-24 hours.

17. The preparation method of the electrode material coated with a solid electrolyte according to claim 9, characterized in that, The heat treatment temperature is 400-900° C., and the heat treatment time is 1-48 hours.

18. The preparation method of the electrode material coated with a solid electrolyte according to claim 9, characterized in that, The heat treatment atmosphere is at least one of nitrogen, argon, oxygen and air.

19. An application of the solid electrolyte coated electrode material according to any one of claims 1 to 8 or the method for preparing the solid electrolyte coated electrode material according to any one of claims 9 to 18 in all-solid-state lithium metal, all-solid-state lithium ion batteries, semi-solid-state lithium ion batteries, lithium-air batteries, all-solid-state sodium metal batteries, all-solid-state sodium ion batteries and semi-solid-state sodium ion batteries.

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