Solid electrolyte material, solid electrolyte, positive electrode material and manufacturing method thereof, and sodium ion battery

Abstract

The present invention relates to the field of sodium ion batteries and discloses a solid electrolyte material, a solid electrolyte, a positive electrode material, a method for producing the same, and a sodium ion battery. (020) and (421) crystal plane peak intensity I (421) The ratio is 0.9≦I (020) / I (421) <1, and the peak area A of the (020) crystal plane obtained by XRD (020) and the peak area A of the (421) crystal plane (421) The ratio is 0.45≦A (020) / A (421) <1. The solid electrolyte material has good crystallinity, high ionic conductivity, and good structural stability. The cathode material made from the solid electrolyte material has high capacity, excellent rate, cycle, and thermal stability.

Description

[Technical Field]

[0001] The present invention relates to the field of sodium ion batteries, and more particularly to a solid electrolyte material, a solid electrolyte, a positive electrode material and a manufacturing method thereof, and a sodium ion battery. [Background technology]

[0002] Lithium-ion secondary batteries have advantages such as a high specific energy density, a wide operating temperature range, a long charge / discharge life, low self-discharge, and a small memory effect, and their mass energy density can reach 270Wh / kg, making them the most promising chemical power source. Since their commercialization by Sony in 1990, they have not only occupied a leading position in the fields of small mobile consumer electronics such as laptops, video cameras, digital cameras, and MP3 players, but also in recent years have shown notable development prospects in the fields of power batteries and energy storage batteries.

[0003] However, lithium resources on Earth are not abundant, accounting for only 0.0065% of the elemental lithium in the Earth's crust, and their distribution is uneven. With the advent of the future era of electric vehicles and smart grids, the scarcity of lithium resources and their high cost will inevitably become major constraints on their development. Therefore, the development of new energy storage battery systems is highly necessary. The abundance of sodium in the Earth's crust reaches 2.64%, making it inexpensive. Furthermore, sodium ions and lithium ions share similar insertion mechanisms. Therefore, sodium-ion secondary batteries have attracted renewed attention in recent years.

[0004] However, most of the currently reported research on sodium batteries uses liquid electrolytes based on organic solvents such as ethers and carbonates. Organic solvents are flammable and prone to leakage, posing potential safety issues for liquid sodium batteries. In contrast, solid-state sodium batteries offer advantages such as high stability, no risk of leakage, and ease of direct lamination processing, significantly improving the safety performance of the battery.

[0005] One of the most important materials in solid-state battery systems is currently the solid electrolyte. There are various types of solid electrolytes, including organic polymers, sulfides, halides, perovskite, NASICON, and garnet. Among them, NASICON solid electrolytes have advantages such as high electrical conductivity, good thermal stability, and a wide electrochemical window, making them one of the solid electrolytes with the greatest potential for industrialization.

[0006] The theoretical ionic conductivity of NASICON-type solid electrolytes is 10 -3 S / cm or more, but current research reports generally show values ​​of 0.5×10 -3 S / cm, so its ionic conductivity still has room for improvement. Second, issues such as poor compatibility at the electrode-electrolyte interface limit its practical use. NASICON-type solid electrolytes suffer from unstable structure and easy phase separation after nano-processing, which makes long-term storage of nano-slurries undesirable. To effectively improve their ionic conductivity, researchers have used wet chemical reaction methods such as hydrothermal and sol-gel processes to improve their performance, but they are not low-cost and cannot be produced on a large scale. Traditional solid-state reactions result in heterogeneous mixing of raw materials, resulting in the formation of heterogeneous phases. Meanwhile, the sodium content remaining on the surface of mainstream sodium-layered positive electrode materials on the market is too high, which affects the diffusion and transmission of sodium ions and destroys the material structure, resulting in reduced battery cycle life, energy efficiency, and safety. Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention aims to overcome the problems of conventional solid electrolyte materials, which still have low ionic conductivity and poor structural stability. [Means for solving the problem]

[0008] In order to achieve the above object, a first aspect of the present invention provides a solid electrolyte material, wherein the peak intensity I of a (020) crystal plane obtained by XRD of the solid electrolyte material is(020) and (421) crystal plane peak intensity I (421) The ratio is 0.9≦I (020) / I (421) <1, The peak area A of the (020) crystal plane obtained by XRD of the solid electrolyte material (020) and the peak area A of the (421) crystal plane (421) The ratio is 0.45≦A (020) / A (421) <1.

[0009] A second aspect of the present invention provides a method for producing the solid electrolyte material according to the first aspect, the method comprising: (1) A Na source, a Zr source, a Si source, and a P source are mixed in the presence of a solvent to obtain a mixture A, and optionally, M 1 Source and / or M 2 a source; (2) heating the mixture A, the mixture B containing the organic monomer, the initiator, and the catalyst to cause a polymerization reaction, thereby obtaining a solid electrolyte precursor I; (3) sequentially pre-sintering and pulverizing the solid electrolyte precursor I to obtain a solid electrolyte precursor II; (4) sequentially sintering and pulverizing the solid electrolyte precursor II.

[0010] A third aspect of the present invention provides a solid electrolyte comprising the solid electrolyte material according to the first aspect, a polymer, and a sodium salt.

[0011] A fourth aspect of the present invention provides a method for producing a solid electrolyte according to the third aspect, said method comprising the steps of: (a) kneading a solid electrolyte material, a polymer, and a sodium salt to obtain a mixture; (b) heat-pressing the mixture.

[0012] A fifth aspect of the present invention provides a positive electrode material, the positive electrode material including a positive electrode active material and a solid electrolyte material coated on a surface of the positive electrode active material, the solid electrolyte material being the solid electrolyte material according to the first aspect.

[0013] A sixth aspect of the present invention provides a method of making a cathode material according to the fifth aspect, said method comprising: The method includes a step of heat-treating a mixture containing a solid electrolyte material according to the first aspect and a positive electrode active material at 300-750°C.

[0014] A seventh aspect of the present invention provides a sodium-ion battery comprising the solid electrolyte material according to the first aspect or the positive electrode material according to the fifth aspect. [Effects of the Invention]

[0015] With the above technical solutions, the present invention has the following advantages: (1) The solid electrolyte material according to the present invention has a peak intensity I of the (020) crystal plane obtained by XRD. (020) and (421) crystal plane peak intensity I (421) The ratio is 0.9≦I (020) / I (421) <1, and the peak area A of the (020) crystal plane obtained by XRD (020) and the peak area A of the (421) crystal plane (421) The ratio is 0.45≦A (020) / A (421) <1. The ratio of the peak intensity and peak area of ​​the (020) crystal plane to the (421) crystal plane of the solid electrolyte material is within the above-mentioned specific range, so that the solid electrolyte material has good crystallinity, which ensures that the microscopic morphology of the produced solid electrolyte material is very dense, free of porosity and microcracks, and has a monoclinic phase structure, thereby improving its ionic electrical conductivity. Preferably, the solid electrolyte material is doped with elements, which can reduce the sintering temperature of the material and simultaneously improve the stability and ionic electrical conductivity of the material.

[0016] (2) In the method for producing a solid electrolyte material according to the present invention, doping elements are introduced during the mixing process, resulting in a uniform atomic level mixture of the elements and the main phase, followed by subsequent polymerization of Mixture A with an organic monomer, followed by pre-sintering, sintering, and grinding. At the same time, the contents of Na, Zr, Si, P, and the doping elements, as well as the process conditions of the dry production process, are preferably controlled by adjusting the values ​​of x, y, and z, to comprehensively control the lattice constant. The resulting solid electrolyte material has uniform composition, high ionic conductivity, and a nano-level average particle size. The presence of the doping elements within the lattice provides excellent structural stability, allowing the nano-level slurry to remain in a pure phase state for a long period of time without phase decomposition. Furthermore, the resulting nano-level solid electrolyte slurry and powder have high specific surface area and strong specific surface energy. Furthermore, the method has the advantages of easy raw material acquisition, low cost, simple production method, and ease of industrialization for large-scale mass production.

[0017] (3) In the cathode material of the present invention, a solid electrolyte material is coated on the surface of a cathode active material, and the coating is uniformly distributed. Preferably, the cathode material is subjected to acid-base titration and shows a clear characteristic titration peak within the pH range of 5-8. This indicates that the coating of the NASICON-type solid electrolyte material can widen the diffusion channel for sodium ions, and the cathode material has high capacity, excellent rate, cycle and thermal stability.

[0018] (4) In the method for preparing a cathode material according to the present invention, the surface of the cathode active material is coated with a NASICON-type solid electrolyte material to consume the residual sodium on the surface. At the same time, the NASICON-type solid electrolyte material has three-dimensional sodium ion diffusion channels, which expand after coating, improving the electrochemical performance of the sodium ion battery. Secondly, the NASICON-type solid electrolyte material has a stable structure and excellent thermal stability, which can improve the safety of the cathode material. [Brief explanation of the drawings]

[0019] [Figure 1]1 is an XRD spectrum diagram of the solid electrolyte materials produced in a Production Example and a Comparative Production Example. FIG. [Figure 2] 1 is an XRD spectrum diagram of the solid electrolyte materials produced in a Production Example and a Comparative Production Example after abuse testing. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0020] The endpoints of ranges and any value disclosed herein should be understood to be not limited to such exact ranges or values, but to include values ​​close to those ranges or values. In the case of ranges of numerical values, values ​​between the endpoints of each range, between the endpoints of each range and any single point value, and between any single point value can be combined with each other to create one or more new numerical ranges, and these numerical ranges are considered to be specifically disclosed in the specification.

[0021] In the present invention, unless otherwise specified, the room temperature and normal temperature refer to 25±2°C.

[0022] In the present invention, unless otherwise specified, the term "optionally" as used herein means that the operation is or is not performed, or the material is or is not added.

[0023] As described above, a first aspect of the present invention provides a solid electrolyte material, and a peak intensity I of a (020) crystal plane obtained by XRD of the solid electrolyte material is (020) and (421) crystal plane peak intensity I (421) The ratio is 0.9≦I (020) / I (421) <1, The peak area A of the (020) crystal plane obtained by XRD of the solid electrolyte material (020) and the peak area A of the (421) crystal plane (421) The ratio is 0.45≦A (020) / A (421) <1.

[0024] During the research process, the inventors of the present invention found that the peak intensity and peak area of ​​the (020) crystal plane obtained by XRD and the peak intensity and peak area of ​​the (421) crystal plane obtained by XRD of NASICON-type solid electrolyte material meet the above requirements, and its crystal structure can be controlled. The peak intensity and peak area indicate appropriate crystallinity and good structural stability, and the oxygen atom bond length can be changed, the interaction between Na and O can be weakened, the carrier migration potential energy can be reduced, the carrier concentration can be increased, and its ionic electrical conductivity can be further improved.

[0025] According to some embodiments of the present invention, preferably, 0.97≦I (020) / I (421) < 1, According to some embodiments of the present invention, preferably, 0.46≦A (020) / A (421) <1.

[0026] The above preferred embodiment is advantageous in further improving the ionic conductivity of the solid electrolyte material and in providing better structural stability.

[0027] According to some embodiments of the present invention, the solid electrolyte material preferably has the structure shown in Formula I: Na 3+x [Zr 2-y M 1 y ][Si 2-z M 2 z ]PO 12 Formula I Here, 0≦x<1.15, 0≦y≦0.5, 0≦z≦1, and M 1 is at least one of Mg, La, Y, Al, and Ca, and M 2 is at least one of Ga, In, Ge and Sc.

[0028] According to some embodiments of the present invention, preferably, the average particle size D of the solid electrolyte material 50The nano-level slurry of the solid electrolyte material can be left standing for a long time without causing phenomena such as precipitation and material phase decomposition.

[0029] According to some embodiments of the present invention, preferably, the ionic conductivity of the solid electrolyte material is 8×10 -5 S / cm, preferably greater than 1×10 -4 Greater than S / cm.

[0030] A second aspect of the present invention provides a method for producing the solid electrolyte material according to the first aspect, the method comprising: (1) A Na source, a Zr source, a Si source, and a P source are mixed in the presence of a solvent to obtain a mixture A, and optionally, M 1 Source and / or M 2 a source; (2) heating the mixture A, the mixture B containing the organic monomer, the initiator, and the catalyst to cause a polymerization reaction, thereby obtaining a solid electrolyte precursor I; (3) sequentially pre-sintering and pulverizing the solid electrolyte precursor I to obtain a solid electrolyte precursor II; (4) sequentially sintering and pulverizing the solid electrolyte precursor II.

[0031] According to some embodiments of the present invention, preferably in step (1), the solvent is selected from at least one of water, N-methyl-2-pyrrolidone, phthalate esters, dibasic acid esters, long-chain alcohols, and pyrrolidones, and is preferably water.

[0032] According to some embodiments of the present invention, preferably in step (1), the Na source is selected from at least one of oxides, hydroxides, nitrates, oxalates, organic alkoxides, and carbonates containing Na, and is preferably sodium carbonate.

[0033] According to some embodiments of the present invention, preferably in step (1), the Zr source is selected from at least one of oxides, hydroxides, nitrates, oxalates, organic alkoxides, and carbonates containing Zr, and is preferably at least one of ZrO, zirconium silicate, and zirconium tetrachloride, and more preferably ZrO.

[0034] According to some embodiments of the present invention, preferably in step (1), the Si source is selected from at least one of oxides, hydroxides, nitrates, oxalates, organic alkoxides, and carbonates containing Si, and is preferably at least one of SiO, sodium silicate, and silicon carbide, and more preferably SiO.

[0035] According to some embodiments of the present invention, preferably in step (1), the P source is at least one of NH4H2PO4, sodium dihydrogen phosphate, and phosphoric acid, and preferably NH4H2PO4.

[0036] According to some embodiments of the present invention, preferably, in step (1), the M 1 Source and M 2 The sources are independently M 1 and / or M 2 and preferably, the compound is selected from at least one of oxides, hydroxides, nitrates, oxalates, organic alkoxides, and carbonates containing the compound M. 1 The source is Y2O3 and / or La2O3, preferably 2 The source is at least one of Sc2O3, Ga2O3, and GeO2.

[0037] According to some embodiments of the present invention, preferably, in step (1), the ratio n(Na) / n(Si) of the molar amount of Na in the Na source to the molar amount of Si in the Si source is 1.65-1.725, and the mixture A further contains M 2 When a source is included, the molar amount of Na in the Na source, the molar amount of Si in the Si source, and the M 2 M in Genchu2 The ratio of the molar amount of Na to the sum of n(Na) / [n(Si)+n(M 2 )] is 1.65-1.725.

[0038] According to some embodiments of the present invention, preferably, in step (1), the Na source, the Zr source, the Si source, the P source, the M 1 source and said M 2 Depending on the amounts of the sources used, the obtained solid electrolyte material has a structure shown in Formula I. For the specific structure, see above and the explanation will be omitted here. 1 source and said M 2 The molar amounts of sources used satisfy the stoichiometric ratios of the structure shown in Formula I.

[0039] According to some embodiments of the present invention, preferably, in step (1), the solid content of the mixture A at 25° C. is 40-60 wt %.

[0040] According to some embodiments of the present invention, in step (1), the mixing can be preferably carried out in an apparatus having a conventional mixing and / or grinding function, and there is no particular limitation thereto, for example, in a planetary ball mill or a high-energy ball mill.

[0041] According to some embodiments of the present invention, preferably in step (2), the organic monomer is selected from at least one of acrylamide (AM), methylenebisacrylamide (MBAM), styrene, butadiene, and methyl methacrylate, and is preferably acrylamide.

[0042] According to some embodiments of the present invention, preferably in step (2), the initiator is selected from at least one of benzoyl peroxide, (NH)S0 and KS0, preferably (NH)S0.

[0043] According to some embodiments of the present invention, preferably in step (2), the catalyst is N,N,N',N'-tetramethylethylenediamine (TEMED).

[0044] According to some embodiments of the present invention, preferably, in step (2), the mass ratio of the mixture A to the organic monomer is 1:0.5-0.6.

[0045] According to some embodiments of the present invention, preferably, in step (2), the mass ratio of the organic monomer, the initiator, and the catalyst is 1:0.5-1.5:0.5-1.5.

[0046] According to some embodiments of the present invention, preferably, in step (2), the polymerization reaction conditions include a polymerization temperature of 80-200° C. and a polymerization time of 10-15 hours.

[0047] According to some embodiments of the present invention, preferably, in step (3), the pre-sintering conditions include a pre-sintering temperature of 300-700° C. and a pre-sintering time of 2-6 hours.

[0048] According to some embodiments of the present invention, in step (3), the average particle size D 50 is 1-50 μm, preferably 40-50 μm.

[0049] According to some embodiments of the present invention, in step (4), the sintering conditions preferably include a sintering temperature of 1000-1200°C and a sintering time of 4-10 hours. The adoption of the above preferred embodiment is advantageous for synthesizing a monoclinic solid electrolyte material.

[0050] According to some embodiments of the present invention, the method preferably further comprises a step of nano-processing the pulverized product of step (4) in the presence of water to obtain a nano-level solid electrolyte material. 50is advantageous for obtaining a nano-level solid electrolyte material that satisfies the above requirements.

[0051] Preferably, the nano-processing step includes sanding the ground product described in step (4) in the presence of water to obtain a nano-level slurry with a solid content of 40-60wt% at 25°C, and drying the nano-level slurry and polishing the obtained dried product. Preferably, the sanding conditions are a rotation speed of 800-1200r / min and a time of 1-3 hours, and the drying method is preferably at least one of blow drying, vacuum drying and freeze drying, and the drying conditions include a temperature of 25-60°C and a time of 8-12 hours, and the polishing is performed in an airflow mill.

[0052] A third aspect of the present invention provides a solid electrolyte comprising the solid electrolyte material according to the first aspect, a polymer, and a sodium salt.

[0053] According to some embodiments of the present invention, preferably the polymer is selected from at least one of polyvinylidene fluoride, polytetrafluoroethylene, vinylidene fluoride-hexafluoropropylene copolymer, polyethylene oxide, polydimethylsiloxane, polymethyl methacrylate, polypropylene carbonate, polyethylene carbonate and polycaprolactone, preferably polyethylene oxide (PEO).

[0054] According to some embodiments of the present invention, preferably the sodium salt is selected from at least one of NaTFSI, sodium hexafluorophosphate, sodium perchlorate and sodium trifluoromethanesulfonate, preferably NaTFSI.

[0055] According to some embodiments of the present invention, preferably, based on the total mass of the solid electrolyte, the content of the solid electrolyte material is 5-30 wt %, the content of the polymer is 50-75 wt %, and the content of the sodium salt is 15-30 wt %.

[0056] According to some embodiments of the present invention, the solid electrolyte is preferably a membrane-like structure, and the thickness of the membrane-like structure is 5-200 μm, preferably 20-100 μm.

[0057] A fourth aspect of the present invention provides a method for producing a solid electrolyte according to the third aspect, said method comprising the steps of: (a) kneading a solid electrolyte material, a polymer, and a sodium salt to obtain a mixture; (b) heat-pressing the mixture.

[0058] According to some embodiments of the present invention, preferably, the kneading conditions described in step (a) are a kneading temperature of 0.5-1.5T m and T m is the softening temperature of the polymer, the rotation speed is 300-500 rpm, and the kneading time includes when the torque of the kneader becomes stable.

[0059] According to some embodiments of the present invention, the conditions for the heat pressing treatment in step (b) preferably include a heat pressing temperature of 60-80°C, a heat pressing pressure of 1-10 MPa, and a heat pressing time of 5-20 minutes. The heat pressing pressure can be adjusted depending on the required thickness of the solid electrolyte membrane. The apparatus used for the heat pressing treatment is not particularly limited, and can be selected from, for example, at least one of a plate-type hot press, a roll-type hot press, and a pulse-type hot press.

[0060] According to some embodiments of the present invention, preferably, the method further comprises a step of drying the heat-pressed product of step (b), wherein the drying conditions include a drying temperature of 60-120°C and a drying time of 4-24 hours.

[0061] A fifth aspect of the present invention provides a cathode material comprising a cathode active material and a solid electrolyte material coated on a surface of the cathode active material, wherein the solid electrolyte material is the solid electrolyte material according to the first aspect.

[0062] According to some embodiments of the present invention, preferably, the mass ratio of the solid electrolyte material to the positive electrode active material is 0.05-1:100, preferably 0.5-0.8:100.

[0063] According to some embodiments of the present invention, preferably the positive electrode active material is NaNi 1 / 3 Fe 1 / 3 Mn 1 / 3 O2, Na 2 / 3 Ni 1 / 3 Mn 1 / 2 O2 and layered structure oxide positive electrode materials derived therefrom. The layered structure oxide positive electrode materials derived therefrom include NaNi 1 / 3 Fe 1 / 3 Mn 1 / 3 O2 and / or Na 2 / 3 Ni 1 / 3 Mn 1 / 2 It is a layered structure oxide cathode material obtained after element doping and / or element ratio adjustment to O2, for example, Na 0.45 Ni 0.22 Co 0.11 Mn 0.66 O2, Na[Ni 0.25 Fe 0.5 Mn 0.25 ]O2, NaNi 0.25 Fe 0.25 Co 0.25 Mn 0.25 These include, but are not limited to, at least one of O2.

[0064] According to some embodiments of the present invention, preferably, when the positive electrode material is subjected to acid-base titration, there is a characteristic titration peak between pH=5 and pH=8. This indicates that the solid electrolyte material according to the present invention generates Na3PO4 at the interface with the positive electrode active material during coating, which is a fast ion conductor and can be used as a buffer layer to balance the potential difference between the NASICON-type solid electrolyte material and the positive electrode active material, thereby mitigating the generation of a space charge layer and reducing the interfacial impedance, which is advantageous for better performance of the electrochemical properties of the positive electrode material.

[0065] According to some embodiments of the present invention, the onset temperature of the main exothermic peak in the differential scanning calorimetry spectrum of the positive electrode material is preferably 290° C. or higher. The significant delay in the onset temperature of the main exothermic peak of the positive electrode material indicates that the solid electrolyte material according to the present invention can improve the thermal stability of the resulting positive electrode material after being coated on the surface of a positive electrode active material.

[0066] The positive electrode material can improve the structural stability, alleviate the problem of oxygen precipitation under highly sodium-free conditions, reduce the occurrence of side reactions between the positive electrode material and the electrolyte under high voltage conditions, and improve the electrochemical performance and safety of sodium-ion batteries.

[0067] A sixth aspect of the present invention provides a method of making a cathode material according to the fifth aspect, said method comprising: The method includes a step of heat-treating a mixture containing a solid electrolyte material and a positive electrode active material at 300-750°C, wherein the solid electrolyte material is the solid electrolyte material according to the first aspect.

[0068] According to some embodiments of the present invention, the mixture is preferably obtained by mixing the solid electrolyte material and the positive electrode active material in a mixer, and the mixer may be a conventional dry mixer such as, but not limited to, a ball mill, a high-pressure mixer, a vertical mixer, a horizontal mixer, an inclined mixer, etc. Preferably, the heating device for the heat treatment may be a conventional sintering and heat treatment device such as, but not limited to, a tubular furnace, an oxygen furnace, a muffle furnace, a roller kiln, etc.

[0069] According to some embodiments of the present invention, preferably, the temperature of the heat treatment is 400-750° C., and preferably, the time of the heat treatment is 2-12 h, preferably 5-12 h.

[0070] A seventh aspect of the present invention provides a sodium-ion battery comprising the solid electrolyte material according to the first aspect or the positive electrode material according to the fifth aspect.

[0071] The present invention will be described in detail below with reference to examples.

[0072] In the following examples and comparative examples, all raw materials used are commercially available unless otherwise specified.

[0073] In the following examples and comparative examples, The material phase and crystal structure were analyzed using an automatic X-ray diffractometer manufactured by Rigaku Co., Ltd. in Japan. The particle size distribution test was carried out using a Malvern Mastersizer 2000 laser particle size distribution analyzer. 50 Characterize only We performed charge / discharge and cycle tests on button batteries using the CT-3008 from Shinwei Electronics Co., Ltd. AC impedance and electrochemical window tests are performed using the SP-150 electrochemical workstation from Bio-logic, France.

[0074] The preparation examples illustrate the solid electrolyte material according to the present invention and the method for preparing the solid electrolyte material.

[0075] Manufacturing Example 1 (1) Mixing a Na source, a Zr source, a Si source, and a P source in the presence of a solvent to obtain a mixture A; The solvent is water, the Na source is Na2CO3, the Zr source is ZrO2, the Si source is SiO2, and the P source is NH4H2PO4; The ratio n(Na) / n(Si) of the molar amount of Na in the Na source to the molar amount of Si in the Si source is 1.65, Mixing was carried out using a ball mill mixer, and the mixing conditions were a rotation speed of 900 rpm and a time of 6 hours. Mixture A has a solids content of 50 wt % at 25°C. (2) Mixture A and mixture B containing an organic monomer, an initiator, and a catalyst are heated to polymerize, thereby obtaining a solid electrolyte precursor I; The organic monomer is acrylamide, the initiator is (NH4)2S2O8, and the catalyst is N,N,N',N'-tetramethylethylenediamine (TEMED), The mass ratio of mixture A to the organic monomer was 1:0.55, and the mass ratio of the organic monomer, initiator, and catalyst was 1:1:1. Mixture B is obtained by adding an organic monomer, an initiator, and a catalyst to Mixture A and dispersing the mixture by stirring. The polymerization reaction was carried out in a fan oven, and the conditions for the polymerization reaction were a polymerization temperature of 100° C. and a polymerization time of 12 hours. (3) Pre-sintering the solid electrolyte precursor I in sequence and pulverizing the solid electrolyte precursor II, pre-sintering is carried out in a muffle furnace, and the pre-sintering conditions are a pre-sintering temperature of 500°C and a pre-sintering time of 2 hours; The crushing process was carried out using a breaker, and the average particle size of the solid electrolyte precursor II was D 50 is 48 μm. (4) The solid electrolyte precursor II is successively sintered and pulverized to obtain a micron-order solid electrolyte material, and its average particle size D 50 is 13 μm and the chemical formula is Na3Zr2Si2PO 12 and The sintering is carried out in a muffle furnace, and the sintering conditions are that the sintering temperature is 1050°C and the sintering time is 8 hours, and the crushing process is carried out in an airflow mill. (5) In the presence of water, the micron-order solid electrolyte material is nano-processed to obtain a nano-level solid electrolyte material, and its average particle size D 50 is 148 nm, The nano-processing is performed by sanding the micron-order solid electrolyte material and water with a sand mill to obtain a nano-level slurry, the solid content of which is 50 wt% at 25 ° C., and then drying the nano-level slurry and polishing the dried product obtained with an airflow mill; The sanding conditions were a rotation speed of 1000 r / min and a time of 2 hours. The drying conditions were a temperature of 60°C and a time of 12 hours.

[0076] Manufacturing Example 2 (1) In the presence of a solvent, a Na source, an M1 source, a Zr source, a Si source, and a P source are mixed to obtain a mixture A, in which the solvent is water, the Na source is Na2CO3, the Zr source is ZrO2, the Si source is SiO2, the P source is NH4H2PO4, and M 1 The source is Y2O3, The ratio n(Na) / n(Si) of the molar amount of Na in the Na source to the molar amount of Si in the Si source is 1.65, The mixing was carried out using a ball mill mixer, and the mixing conditions were a rotation speed of 900 rpm and a time of 6 hours. Mixture A has a solids content of 50 wt% at 25°C. (2) Mixture A and mixture B containing an organic monomer, an initiator, and a catalyst are heated to polymerize, thereby obtaining a solid electrolyte precursor I; The organic monomer is acrylamide, the initiator is (NH4)2S2O8, and the catalyst is N,N,N',N'-tetramethylethylenediamine (TEMED), The mass ratio of mixture A to the organic monomer was 1:0.55, and the mass ratio of the organic monomer, initiator, and catalyst was 1:1:1. Mixture B is obtained by adding an organic monomer, an initiator, and a catalyst to Mixture A and dispersing the mixture by stirring. The polymerization reaction was carried out in a fan oven, and the polymerization reaction conditions were a polymerization temperature of 100°C and a polymerization time of 12 hours. (3) The solid electrolyte precursor I is sequentially pre-sintered and pulverized to obtain a solid electrolyte precursor II, and the pre-sintering is carried out in a muffle furnace, and the pre-sintering conditions are a pre-sintering temperature of 450°C and a pre-sintering time of 2 hours; The crushing process was carried out using a breaker, and the average particle size of the solid electrolyte precursor II was D 50 is 45 μm. (4) The solid electrolyte precursor II is successively sintered and pulverized to obtain a micron-order solid electrolyte material, and its average particle size D 50 is 14 μm and has the chemical formula Na 3.05 Zr 1.95 Y 0.05 SiPO 12 and The sintering is carried out in a muffle furnace, and the sintering conditions are that the sintering temperature is 1050°C and the sintering time is 6 hours, and the crushing process is carried out in an airflow mill. (5) In the presence of water, the micron-order solid electrolyte material is nano-processed to obtain a nano-level solid electrolyte material, and its average particle size D 50 is 128 nm, The nano-processing is performed by sanding the micron-order solid electrolyte material and water with a sand mill to obtain a nano-level slurry, and the solid content of the nano-level slurry at 25°C is 50wt%. Then, the nano-level slurry is dried and the dried product obtained is polished with an airflow mill; The sanding conditions were a rotation speed of 1000 r / min and a time of 2 hours. The drying conditions were a temperature of 60°C and a time of 12 hours.

[0077] Manufacturing Example 3 (1) In the presence of a solvent, a Na source, M 2A source of Na, a source of Zr, a source of Si, and a source of P were mixed to obtain a mixture A, in which the solvent was water, the source of Na was Na2CO3, the source of Zr was ZrO2, the source of Si was SiO2, the source of P was NH4H2PO4, and M 2 The source is Sc2O3, The molar amount of Na in the Na source, the molar amount of Si in the Si source, and M 2 M in Genchu 2 The ratio of the molar amount of Na to the sum of n(Na) / [n(Si)+n(M 2 )] is 1.65, The mixing was carried out using a ball mill mixer, and the mixing conditions were a rotation speed of 900 rpm and a time of 6 hours. Mixture A has a solids content of 50 wt% at 25°C. (2) Mixture A and mixture B containing an organic monomer, an initiator, and a catalyst are heated to polymerize, thereby obtaining a solid electrolyte precursor I; The organic monomer is acrylamide, the initiator is (NH4)2S2O8, and the catalyst is N,N,N',N'-tetramethylethylenediamine (TEMED), The mass ratio of mixture A to the organic monomer was 1:0.55, and the mass ratio of the organic monomer, initiator, and catalyst was 1:1:1. Mixture B is obtained by adding an organic monomer, an initiator, and a catalyst to Mixture A and dispersing the mixture by stirring. The polymerization reaction was carried out in a fan oven, and the polymerization reaction conditions were a polymerization temperature of 100°C and a polymerization time of 12 hours. (3) Pre-sintering the solid electrolyte precursor I in sequence and pulverizing the solid electrolyte precursor II, pre-sintering is carried out in a muffle furnace, and the pre-sintering conditions are a pre-sintering temperature of 400°C and a pre-sintering time of 3 hours; The crushing process was carried out using a breaker, and the average particle size of the solid electrolyte precursor II was D 50 is 46 μm. (4) The solid electrolyte precursor II is successively sintered and pulverized to obtain a micron-order solid electrolyte material, and its average particle size D 50 is 14 μm and has the chemical formula Na 3.05 Zr2Si 1.95 Sc 0.05PO 12 and The sintering is carried out in a muffle furnace, and the sintering conditions are that the sintering temperature is 1150°C and the sintering time is 7 hours, and the crushing process is carried out in an airflow mill. (5) In the presence of water, the micron-order solid electrolyte material is nano-processed to obtain a nano-level solid electrolyte material, and its average particle size D 50 is 126 nm, The nano-processing is performed by sanding the micron-order solid electrolyte material and water with a sand mill to obtain a nano-level slurry, and the solid content of the nano-level slurry at 25°C is 50wt%. Then, the nano-level slurry is dried and the dried product obtained is polished with an airflow mill. The sanding conditions were a rotation speed of 1000 r / min and a time of 2 hours. The drying conditions were a temperature of 60°C and a time of 12 hours.

[0078] Manufacturing Example 4 (1) In the presence of a solvent, a Na source, M 1 Source, M. 2 A source of Na, a source of Zr, a source of Si, and a source of P were mixed to obtain a mixture A, in which the solvent was water, the source of Na was Na2CO3, the source of Zr was ZrO2, the source of Si was SiO2, the source of P was NH4H2PO4, and M 1 The source is Y2O3 and M 2 The source is Sc2O3, The molar amount of Na in the Na source, the molar amount of Si in the Si source, and M 2 M in Genchu 2 The ratio of the molar amount of Na to the sum of n(Na) / [n(Si)+n(M 2 )] is 1.65, The mixing was carried out using a ball mill mixer, and the mixing conditions were a rotation speed of 900 rpm and a time of 6 hours. Mixture A has a solids content of 50 wt% at 25°C. (2) Mixture A and mixture B containing an organic monomer, an initiator, and a catalyst are heated to polymerize, thereby obtaining a solid electrolyte precursor I; The organic monomer is acrylamide, the initiator is (NH4)2S2O8, and the catalyst is N,N,N',N'-tetramethylethylenediamine (TEMED), The mass ratio of mixture A to the organic monomer was 1:0.55, and the mass ratio of the organic monomer, initiator, and catalyst was 1:1:1. Mixture B is obtained by adding an organic monomer, an initiator, and a catalyst to Mixture A and dispersing the mixture by stirring. The polymerization reaction was carried out in a fan oven, and the polymerization reaction conditions were a polymerization temperature of 100°C and a polymerization time of 12 hours. (3) Pre-sintering the solid electrolyte precursor I in sequence and pulverizing the solid electrolyte precursor II, and pre-sintering is performed in a muffle furnace, and the pre-sintering conditions are as follows: the pre-sintering temperature is 550°C, and the pre-sintering time is 2 hours; The crushing process was carried out using a breaker, and the average particle size of the solid electrolyte precursor II was D 50 is 42 μm. (4) The solid electrolyte precursor II is successively sintered and pulverized to obtain a micron-order solid electrolyte material, and its average particle size D 50 is 12 μm and the chemical formula is Na 3.1 Zr 1.95 Y 0.05 Si 1.95 Sc 0.05 PO 12 and Sintering is carried out in a muffle furnace, and the sintering conditions are that the sintering temperature is 1100°C, the sintering time is 8 hours, and the crushing process is carried out in an airflow mill. (5) In the presence of water, the micron-order solid electrolyte material is nano-processed to obtain a nano-level solid electrolyte material, and its average particle size D 50 is 125 nm, The nano-processing is performed by sanding the micron-order solid electrolyte material and water with a sand mill to obtain a nano-level slurry, and the solid content of the nano-level slurry at 25°C is 50wt%. Then, the nano-level slurry is dried and the dried product obtained is polished with an airflow mill; The sanding conditions were a rotation speed of 1000 r / min and a time of 2 hours. The drying conditions were a temperature of 60°C and a time of 12 hours.

[0079] Production Example 5 (1) In the presence of a solvent, a Na source, M 1 Source, M. 2 a source, a Zr source, a Si source, and a P source are mixed to obtain a mixture A, The solvent is water, the Na source is Na2CO3, the Zr source is ZrO2, the Si source is SiO2, the P source is NH4H2PO4, and M 1 The source is Y2O3 and M 2 The source is Ga2O3, The molar amount of Na in the Na source, the molar amount of Si in the Si source, and M 2 M in Genchu 2 The ratio of the molar amount of Na to the sum of n(Na) / [n(Si)+n(M 2 )] is 1.65, The mixing was carried out using a ball mill mixer, and the mixing conditions were a rotation speed of 900 rpm and a time of 6 hours. Mixture A has a solids content of 50 wt% at 25°C. (2) Mixture A and mixture B containing an organic monomer, an initiator, and a catalyst are heated to polymerize, thereby obtaining a solid electrolyte precursor I; The organic monomer is acrylamide, the initiator is (NH4)2S2O8, and the catalyst is N,N,N',N'-tetramethylethylenediamine (TEMED), The mass ratio of mixture A to the organic monomer was 1:0.55, and the mass ratio of the organic monomer, initiator, and catalyst was 1:1:1. Mixture B is obtained by adding an organic monomer, an initiator, and a catalyst to Mixture A and dispersing the mixture by stirring. The polymerization reaction was carried out in a fan oven, and the polymerization reaction conditions were a polymerization temperature of 100°C and a polymerization time of 12 hours. (3) Pre-sintering the solid electrolyte precursor I in sequence and pulverizing the solid electrolyte precursor II, pre-sintering is performed in a muffle furnace, and the pre-sintering conditions are a pre-sintering temperature of 500°C and a pre-sintering time of 2 hours; The crushing process was carried out using a breaker, and the average particle size of the solid electrolyte precursor II was D 50 is 44 μm. (4) The solid electrolyte precursor II is successively sintered and pulverized to obtain a micron-order solid electrolyte material, and its average particle size D 50 is 12 μm and the chemical formula is Na 3.1 Zr 1.95 Y 0.05 Si 1.95 Ga 0.05 PO 12 and Sintering is carried out in a muffle furnace, and the sintering conditions are a sintering temperature of 1100°C, a sintering time of 8 hours, and crushing treatment in an airflow mill. (5) In the presence of water, the micron-order solid electrolyte material is nano-processed to obtain a nano-level solid electrolyte material, and its average particle size D 50 is 137 nm, The nano-processing is to sand the micron-order solid electrolyte material and water with a sand mill to obtain a nano-level slurry, and the solid content of the nano-level slurry at 25°C is 50wt%; then, the nano-level slurry is dried, and the dried product obtained is polished with an airflow mill; The sanding conditions were a rotation speed of 1000 r / min and a time of 2 hours. The drying conditions were a temperature of 60°C and a time of 12 hours.

[0080] Manufacturing Example 6 (1) In the presence of a solvent, a Na source, M 1 Source, M. 2 A source of Na, a source of Zr, a source of Si, and a source of P were mixed to obtain a mixture A, in which the solvent was water, the source of Na was Na2CO3, the source of Zr was ZrO2, the source of Si was SiO2, the source of P was NH4H2PO4, and M 1 The source is Y2O3 and M 2 The source is GeO2, The molar amount of Na in the Na source, the molar amount of Si in the Si source, and M 2 M in Genchu 2 The ratio of the sum of the molar amounts of n(Na) / [n(Si)+n(M 2 )] is 1.65, The mixing was carried out using a ball mill mixer, and the mixing conditions were a rotation speed of 900 rpm and a time of 6 hours. Mixture A has a solids content of 50 wt% at 25°C. (2) Mixture A and mixture B containing an organic monomer, an initiator, and a catalyst are heated to polymerize, thereby obtaining a solid electrolyte precursor I; The organic monomer is acrylamide, the initiator is (NH4)2S2O8, and the catalyst is N,N,N',N'-tetramethylethylenediamine (TEMED), The mass ratio of mixture A to the organic monomer was 1:0.55, and the mass ratio of the organic monomer, initiator, and catalyst was 1:1:1. Mixture B is obtained by adding an organic monomer, an initiator, and a catalyst to Mixture A and dispersing the mixture by stirring. The polymerization reaction was carried out in a fan oven, and the polymerization reaction conditions were a polymerization temperature of 100°C and a polymerization time of 12 hours. (3) Pre-sintering the solid electrolyte precursor I in sequence and pulverizing the solid electrolyte precursor II, and pre-sintering is performed in a muffle furnace, and the pre-sintering conditions are as follows: the pre-sintering temperature is 500°C, and the pre-sintering time is 2 hours; The crushing process was carried out using a breaker, and the average particle size of the solid electrolyte precursor II was D 50 is 44 μm. (4) The solid electrolyte precursor II is successively sintered and pulverized to obtain a micron-order solid electrolyte material, and its average particle size D 50 is 12 μm and the chemical formula is Na 3.05 Zr 1.95 Y 0.05 Si 1.95 Ge 0.05 PO 12 and Sintering is carried out in a muffle furnace, and the sintering conditions are that the sintering temperature is 1100°C, the sintering time is 8 hours, and the crushing process is carried out in an airflow mill. (5) In the presence of water, the micron-order solid electrolyte material is nano-processed to obtain a nano-level solid electrolyte material, and its average particle size D 50 is 132 nm, The nano-processing is performed by sanding the micron-order solid electrolyte material and water with a sand mill to obtain a nano-level slurry, and the solid content of the nano-level slurry at 25°C is 50wt%. Then, the nano-level slurry is dried and the dried product obtained is polished with an airflow mill; The sanding conditions were a rotation speed of 1000 r / min and a time of 2 hours. The drying conditions were a temperature of 60°C and a time of 12 hours.

[0081] Manufacturing Example 7 A micron-order solid electrolyte material is obtained in the same manner as in Production Example 1, except that step (5) is not included.

[0082] Manufacturing Example 8 (1) In the presence of a solvent, a Na source, M 1 A source of Na, a source of Zr, a source of Si, and a source of P were mixed to obtain a mixture A, in which the solvent was water, the source of Na was Na2CO3, the source of Zr was ZrO2, the source of Si was SiO2, the source of P was NH4H2PO4, and M 1 The source is La2O3, The ratio n(Na) / n(Si) of the molar amount of Na in the Na source to the molar amount of Si in the Si source is 1.65, The mixing was carried out using a ball mill mixer, and the mixing conditions were a rotation speed of 900 rpm and a time of 6 hours. Mixture A has a solids content of 50 wt% at 25°C. (2) Mixture A and mixture B containing an organic monomer, an initiator, and a catalyst are heated to polymerize, thereby obtaining a solid electrolyte precursor I; The organic monomer is acrylamide, the initiator is (NH4)2S2O8, and the catalyst is N,N,N',N'-tetramethylethylenediamine (TEMED), The mass ratio of mixture A to the organic monomer was 1:0.55, and the mass ratio of the organic monomer, initiator, and catalyst was 1:1:1. Mixture B is obtained by adding an organic monomer, an initiator, and a catalyst to Mixture A and dispersing the mixture by stirring. The polymerization reaction was carried out in a fan oven, and the polymerization reaction conditions were a polymerization temperature of 100°C and a polymerization time of 12 hours. (3) The solid electrolyte precursor I is sequentially pre-sintered and pulverized to obtain a solid electrolyte precursor II, and the pre-sintering is carried out in a muffle furnace, and the pre-sintering conditions are a pre-sintering temperature of 450°C and a pre-sintering time of 2 hours; The crushing process was carried out using a breaker, and the average particle size of the solid electrolyte precursor II was D 50 is 43 μm. (4) The solid electrolyte precursor II is successively sintered and pulverized to obtain a micron-order solid electrolyte material, and its average particle size D 50 is 10 μm and the chemical formula is Na 3.05 Zr 1.95 La 0.05 SiPO 12 and The sintering is carried out in a muffle furnace, and the sintering conditions are that the sintering temperature is 1050°C and the sintering time is 6 hours, and the crushing process is carried out in an airflow mill.

[0083] Comparative Manufacturing Example 1 (1) Mixing a Na source, a Zr source, a Si source, and a P source to obtain a mixture, The Na source is Na2CO3, the Zr source is ZrO2, the Si source is SiO2, and the P source is NH4H2PO4, The ratio n(Na) / n(Si) of the molar amount of Na in the Na source to the molar amount of Si in the Si source is 1.65, The mixing was carried out using a ball mill mixer, and the mixing conditions were a rotation speed of 900 rpm and a time of 6 hours. (2) The mixture is sequentially pre-sintered and pulverized to obtain a solid electrolyte precursor; The pre-sintering was carried out in a muffle furnace, and the pre-sintering conditions were a pre-sintering temperature of 700°C, a pre-sintering time of 2 hours, a crushing process in a breaker, and an average particle size D of the solid electrolyte precursor. 50 is 45 μm. (3) The solid electrolyte precursor is sequentially sintered and pulverized to obtain a micron-order solid electrolyte material, and its average particle size D 50 is 15 μm and the chemical formula is Na3Zr2Si2PO12 and Sintering is carried out in a muffle furnace, and the sintering conditions are a sintering temperature of 1050°C, a sintering time of 8 hours, and crushing treatment in an airflow mill.

[0084] Test example 1 (a) The solid electrolyte material obtained in each of the Production Examples and the Comparative Production Example, a polymer, and a sodium salt were kneaded to obtain a mixture, in which the amount of the solid electrolyte material used was 8 g, the polymer was polyethylene oxide (PEO) and the amount used was 69 g, and the sodium salt was NaTFSI and the amount used was 23 g. The kneading conditions are a kneading temperature of 85°C, a rotation speed of 500 rpm, and a kneading time during which the torque of the kneader becomes stable. (b) The mixture was placed on the heating table of a plate-type hot press machine and heat-pressed to obtain a solid electrolyte membrane having a thickness of 20 μm. The heat-pressing conditions were a heat-pressing temperature of 70°C, a heat-pressing pressure of 3 MPa, and a heat-pressing time of 20 min.

[0085] The solid electrolyte membrane was punched into a 22 mm diameter disk and vacuum dried at 60°C for 12 hours. After that, in a glove box with an H2O content of <1 ppm and O2 content of <1 ppm, the positive electrode shell, stainless steel plate I (diameter 18 mm, thickness 1 mm), solid electrolyte membrane, stainless steel plate II (diameter 18 mm, thickness 1 mm), nickel foam, and negative electrode shell were assembled in that order and sealed under a pressure of 450 MPa to obtain a test assembly. The test assembly was heated at 65°C for 12 hours for chemical activation, and then charged at a current of 1.3 mA for 5 minutes, allowed to stand for 3 minutes, discharged at a current of 1.3 mA for 5 minutes, allowed to stand for 3 minutes, and cycled three times to perform electrochemical activation, obtaining a sample for ionic conductivity testing.

[0086] The ionic conductivity test sample was placed in an electrochemical workstation to test the AC impedance at room temperature. The test conditions were a disturbance voltage of 5-10 mV and a scanning frequency range of 1 Hz-1 MHz. According to the impedance data obtained by the test, the formula σ = L / (R·S) (where σ is the ionic conductivity in S / cm, L is the thickness of the solid electrolyte membrane after disassembly in cm, R is the impedance value in Ω, and S is the area of ​​the solid electrolyte membrane in cm) was used. 2 The ionic conductivity corresponding to the sample was calculated by the following equation (where: ∑ i = 1 / 2 ⁢ ...

[0087] Test example 2 10 g of each of the solid electrolyte materials obtained in the manufacturing example and the comparative manufacturing example was taken, placed in 90 g of boiling water at 100°C, and stirred for 2 hours. After stirring, the sample was evaporated and dried, and then subjected to XRD testing. The peak intensity I of the (020) crystal plane obtained by XRD was measured. (020) and (421) crystal plane peak intensity I (421) Ratio of I (020) / I (421) , (020) crystal plane peak area A (020) and the peak area A of the (421) crystal plane (421) Ratio A (020) / A (421) The results of the structural stability test are shown in Table 1. XRD spectrum diagrams of the solid electrolyte materials obtained in the Production Example and Comparative Production Example are shown in Figure 1, and XRD spectrum diagrams of the solid electrolyte materials obtained in the Production Example and Comparative Production Example after abuse testing are shown in Figure 2.

[0088] The main body of the solid electrolyte material sample obtained in Preparation Example 1 is a pure phase, and a small amount of sodium phosphate heterophase appears at the diffraction angle positions of 2θ = 28° and 32°. After the abuse treatment, the sample does not have any heterophase, indicating good structural stability of the sample. The solid electrolyte material obtained in Preparation Example 2 is a pure phase, and there are almost no heterophases in the sample after the abuse treatment, which indicates good stability of the sample structure. The solid electrolyte material obtained in Preparation Examples 3-6 was a pure phase, and no heterophase was observed in the sample after abuse treatment, indicating that the sample had excellent stability. The main body of the micron-order solid electrolyte material sample obtained in Preparation Example 7 was a pure phase, and a small amount of sodium phosphate heterophase appeared at diffraction angles of 2θ=26° and 28°. After abuse treatment, the peak intensity of the sodium phosphate heterophase at diffraction angles of 2θ=26° and 28° became stronger, and a large amount of zirconia heterophase appeared at diffraction angle of 2θ=32°, indicating that a phase transition had occurred and the structural stability was poor. The main body of the micron-order solid electrolyte material sample obtained in Comparative Manufacturing Example 1 was a pure phase, and a small amount of sodium phosphate heterophase appeared at diffraction angles of 2θ=26° and 28°. After the sample was subjected to abusive treatment, the peak intensity of the sodium phosphate heterophase at diffraction angles of 2θ=26° and 28° became stronger, and a large amount of zirconia heterophase appeared at diffraction angle of 2θ=32°, indicating that the sample had undergone a phase transition and had poor structural stability. The main body of the micron-order solid electrolyte material sample obtained in Example 8 was a pure phase. After the abuse treatment, a large amount of zirconia heterophase appeared at the diffraction angle position of 2θ = 32°, indicating that the sample underwent a material phase transition and had poor structural stability.

[0089] [Table 1]

[0090] The examples are intended to illustrate cathode materials and methods of making the cathode materials according to the present invention.

[0091] Example 1 S1: The nano-level solid electrolyte material obtained in Preparation Example 1 and the positive electrode active material are mixed in a high mixer to obtain a mixture, and the positive electrode active material is an O3-type layered oxide NaNi 1 / 3 Fe 1 / 3 Mn 1 / 3 O2, The mass ratio of nano-level solid electrolyte material to positive electrode active material is 0.8:100. S2: The obtained mixture is heat-treated in an oxygen furnace to obtain a positive electrode material, in which the nano-level solid electrolyte material is coated on the surface of the positive electrode active material; The heat treatment conditions were a temperature of 500°C and a time of 6 hours.

[0092] Example 2 S1: The nano-level solid electrolyte material obtained in Preparation Example 2 and the positive electrode active material are mixed in a high mixer to obtain a mixture, and the positive electrode active material is P2-type layered oxide Na 2 / 3 Ni 1 / 3 Mn 1 / 2 O2, The mass ratio of the nano-level solid electrolyte material to the positive electrode active material is 0.5:100. S2: The obtained mixture is heat-treated in an oxygen furnace to obtain a positive electrode material, in which the nano-level solid electrolyte material is coated on the surface of the positive electrode active material; The heat treatment conditions were a temperature of 750°C and a time of 12 hours.

[0093] Example 3 S1: The nano-level solid electrolyte material obtained in Preparation Example 3 and the positive electrode active material are mixed in a high mixer to obtain a mixture, and the positive electrode active material is an O3-type layered oxide NaNi 1 / 3 Fe 1 / 3 Mn 1 / 3 O2, The mass ratio of the nano-level solid electrolyte material to the positive electrode active material is 0.5:100. S2: The obtained mixture is heat-treated in an oxygen furnace to obtain a positive electrode material, in which the nano-level solid electrolyte material is coated on the surface of the positive electrode active material; The heat treatment conditions were a temperature of 550°C and a time of 6 hours.

[0094] Example 4 S1: The nano-level solid electrolyte material obtained in Preparation Example 4 and the positive electrode active material are mixed in a high mixer to obtain a mixture, and the positive electrode active material is an O3-type layered oxide NaNi 1 / 3 Fe 1 / 3 Mn 1 / 3 O2, The mass ratio of nano-level solid electrolyte material to positive electrode active material is 0.6:100. S2: The obtained mixture is heat-treated in an oxygen furnace to obtain a positive electrode material, in which the nano-level solid electrolyte material is coated on the surface of the positive electrode active material; The heat treatment conditions were a temperature of 450°C and a time of 10 hours.

[0095] Example 5 S1: The nano-level solid electrolyte material obtained in Preparation Example 5 and the positive electrode active material are mixed in a high mixer to obtain a mixture, and the positive electrode active material is P2-type layered oxide Na 2 / 3 Ni 1 / 3 Mn 1 / 2 O2, The mass ratio of nano-level solid electrolyte material to positive electrode active material is 0.6:100. S2: The obtained mixture is heat-treated in an oxygen furnace to obtain a positive electrode material, in which the nano-level solid electrolyte material is coated on the surface of the positive electrode active material; The heat treatment conditions were a temperature of 450°C and a time of 10 hours.

[0096] Example 6 S1: The nano-level solid electrolyte material obtained in Preparation Example 6 and the positive electrode active material are mixed in a high mixer to obtain a mixture, and the positive electrode active material is P2-type layered oxide Na 2 / 3 Ni 1 / 3 Mn 1 / 2 O2, The mass ratio of nano-level solid electrolyte material to positive electrode active material is 0.6:100. S2: The obtained mixture is heat-treated in an oxygen furnace to obtain a positive electrode material, in which the nano-level solid electrolyte material is coated on the surface of the positive electrode active material; The heat treatment conditions were a temperature of 450°C and a time of 10 hours.

[0097] Example 7 S1: The nano-level solid electrolyte material obtained in Preparation Example 7 and the positive electrode active material were mixed in a high mixer to obtain a mixture, and the positive electrode active material was an O3-type layered oxide NaNi 1 / 3 Fe1 / 3 Mn 1 / 3 O2, The mass ratio of nano-level solid electrolyte material to positive electrode active material is 0.8:100. S2: The obtained mixture is heat-treated in an oxygen furnace to obtain a positive electrode material, in which the nano-level solid electrolyte material is coated on the surface of the positive electrode active material; The heat treatment conditions were a temperature of 500°C and a time of 6 hours.

[0098] Example 8 S1: The micron-order solid electrolyte material obtained in Production Example 8 and the positive electrode active material were mixed in a high mixer to obtain a mixture, and the positive electrode active material was a P2-type layered oxide Na 2 / 3 Ni 1 / 3 Mn 1 / 2 O2, The mass ratio of the micron-order solid electrolyte material to the positive electrode active material is 0.5:100. S2: The obtained mixture is heat-treated in an oxygen furnace to obtain a positive electrode material, in which the micron-order solid electrolyte material is coated on the surface of the positive electrode active material; The heat treatment conditions were a temperature of 750°C and a time of 12 hours.

[0099] Comparative Example 1 Positive electrode active material (O3-type layered oxide NaNi 1 / 3 Fe 1 / 3 Mn 1 / 3 O2) was heat-treated in an oxygen furnace to obtain the cathode material, and the heat-treatment conditions were: temperature 850°C, time 8 hours.

[0100] Comparative Example 2 Positive electrode active material (P2 type layered oxide Na 2 / 3 Ni 1 / 3 Mn 1 / 2 O2) was heat treated in an oxygen furnace to obtain the cathode material, and the heat treatment conditions were: temperature 900°C, time 6 hours.

[0101] Comparative Example 3 S1: The micron-order solid electrolyte material obtained in Comparative Production Example 1 and the positive electrode active material were mixed in a high mixer to obtain a mixture, and the positive electrode active material was an O3-type layered oxide NaNi 1 / 3 Fe 1 / 3 Mn 1 / 3 O2, The mass ratio of the micron-order solid electrolyte material to the positive electrode active material is 0.8:100. S2: The resulting mixture is heat-treated in an oxygen furnace to obtain a cathode material, in which the micron-order solid electrolyte material is coated on the surface of the cathode active material, and the heat treatment conditions are a temperature of 750°C and a time of 12 hours.

[0102] Test example 3 5 g of each of the positive electrode materials obtained in the examples and comparative examples was weighed out and added to 95 g of room temperature deionized water M 水 The slurry obtained after stirring was passed through a Brinell funnel equipped with filter paper and suctioned to obtain a mass of M 濾液 The filtrate is titrated at room temperature using a Metrohm 888 potentiometric titrator to obtain a titration curve. The midpoint of the titration curve is EP x =V x , (x=1, 2, 3) were recorded. The results are shown in Table 2.

[0103] Test example 4 The positive electrode material obtained in each of the examples and comparative examples was mixed with conductive carbon black, PVDF, and NaTFSI in a mass ratio of 90:3:5:2, and an appropriate amount of NMP was added. After uniform stirring, the mixture was scraped onto aluminum foil, dried in a 120°C air oven for 1 hour, and punched into a positive electrode sheet with a diameter of 11 mm. 69 g of PEO and 23 g of NaTFSI were dissolved in acetonitrile and stirred for 12 hours. The resulting slurry was poured into a polytetrafluoroethylene mold and vacuum-dried in an oven at 50 °C for 10 hours. The resulting product was then placed in a press and hot-pressed for 5 minutes, then removed and punched into a 19 mm diameter circular PEO electrolyte membrane. The negative electrode (metallic lithium), the fabricated positive electrode sheet, and the PEO electrolyte membrane were assembled into a 2025-type button cell in an Ar gas glove box with a water and oxygen content of less than 5 ppm. The cells were tested for charge / discharge capacity at 2.0-4.2 V, 0.1 C, and 60 °C, and then tested for charge / discharge cycle performance by charging / discharging 50 times at 2.0-4.2 V, 1 C, and 60 °C. The results are shown in Table 2.

[0104] Test example 5 The positive electrode material obtained in each example and comparative example was mixed with acetylene black and polyvinylidene fluoride (PVDF) in a mass ratio of 95:2.5:2.5, an appropriate amount of NMP was added, and the mixture was stirred uniformly. The mixture was then scraped onto aluminum foil and dried in a 120°C fan oven for 1 hour. It was then punched into a 12mm diameter, 120µm thick positive electrode sheet at 100MPa pressure. The positive electrode sheet was then placed in a vacuum oven and dried at 120°C for 12 hours. Carbon black was used for the negative electrode, a 25µm thick polyethylene porous membrane was used as the separator, and an equal mixture of 1mol / L NaPF6, ethylene carbonate (EC), and propylene carbonate (PC) was used as the electrolyte. The positive electrode sheet, separator, negative electrode sheet, and electrolyte were assembled into a 2025-type button cell in an Ar gas glove box with a water and oxygen content of less than 5ppm.

[0105] The button battery was charged and discharged twice at 2.0-4.2V, 0.2C, and 25°C, and then fully charged and disassembled to obtain the positive electrode pieces. The positive electrode pieces were then placed in a differential thermal thermogravimetry tester to obtain the corresponding DSC curves. The results are shown in Table 2.

[0106] [Table 2]

[0107] As can be seen from the above results, the solid electrolyte material according to the present invention has high ionic conductivity and stable structure. The micron-order solid electrolyte material obtained in Comparative Preparation Example 1 contains a heterogeneous zirconia phase, which affects the grain boundary impedance and has poor structural stability. After being coated on the surface of the positive electrode active material, the heterogeneous phase interferes with the transport of sodium ions, affecting the electrochemical performance of the resulting positive electrode material.

[0108] Although La-doped elements were introduced into the micron-order solid electrolyte material obtained in Preparation Example 8, the elements and the main phase were not uniformly mixed at the atomic level. As a result, heterogeneous zirconia phases appeared after abuse treatment, which affected the grain boundary impedance and poor structural stability. After being coated on the surface of the positive electrode active material, the presence of the heterogeneous phases hindered the transmission of sodium ions, affecting the electrochemical performance of the resulting positive electrode material.

[0109] Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited thereto. Within the technical concept of the present invention, the technical solutions of the present invention may be modified in a number of simple ways, including the combination of each technical feature in any other suitable manner, and these simple modifications and combinations are also considered to be the contents disclosed in the present invention, and all fall within the protection scope of the present invention.

[0110] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of Chinese Patent Application No. 202310788122.0, proposed on June 29, 2023, the contents of which are incorporated herein by reference.

Claims

1. A solid electrolyte material, the solid electrolyte material being a nano-level solid electrolyte material and having a monoclinic phase structure, the solid electrolyte material having a structure shown in Formula I: Na 3+x [Zr 2-y M 1 y ] [Si 2-z M 2 z ] PO 12 Formula I wherein 0≦x<1.15, 0≦y≦0.5, and 0≦z≦1, M 1 is at least one of Mg, La, Y, Al, and Ca, and M 2 is at least one of Ga, In, Ge, and Sc; The peak intensity I of the (020) crystal plane obtained by XRD of the solid electrolyte material （０２０） and the peak intensity I of the (421) crystal plane （４２１） The ratio is 0.9≦I （０２０） / I （４２１） <1, The peak area A of the (020) crystal plane obtained by XRD of the solid electrolyte material （０２０） and the peak area A of the (421) crystal plane （４２１） The ratio of A is 0.45≦A （０２０） / A （４２１） A solid electrolyte material characterized by satisfying <1.

2. 0.97≦I （０２０） / I （４２１） The solid electrolyte material according to claim 1, wherein:

3. The average particle size D of the solid electrolyte material ５０ The solid electrolyte material according to claim 1, wherein the average particle size is 5-500 nm.

4. A method for producing a solid electrolyte material according to any one of claims 1 to 3, the method comprising: (1) In the presence of a solvent, a Na source, a Zr source, a Si source, and a P source are mixed to obtain a mixture A, and optionally, M is further added to the mixture A. １ Source and / or M ２ a source; (2) heating the mixture A, the mixture B containing the organic monomer, the initiator, and the catalyst to cause a polymerization reaction, thereby obtaining a solid electrolyte precursor I; (3) sequentially pre-sintering and pulverizing the solid electrolyte precursor I to obtain a solid electrolyte precursor II; (4) sequentially sintering and grinding the solid electrolyte precursor II.

5. 5. The method of claim 4, wherein in step (1), the solvent is selected from at least one of water, N-methyl-2-pyrrolidone, phthalates, dibasic acid esters, long-chain alcohols, and pyrrolidones.

6. In step (2), the organic monomer is selected from at least one of acrylamide, methylenebisacrylamide, styrene, butadiene, and methyl methacrylate; In step (2), the initiator is benzoyl peroxide, (NH ４ ) ２ S ２ O ８ and K. ２ S ２ O ８ selected from at least one of 5. The method of claim 4, wherein in step (2), the catalyst is N,N,N',N'-tetramethylethylenediamine.

7. In step (2), the mass ratio of the mixture A to the organic monomer is 1:0.5-0.6; In step (2), the mass ratio of the organic monomer, the initiator, and the catalyst is 1:0.5-1.5:0.5-1.5; 5. The method of claim 4, wherein in step (2), the polymerization conditions include a polymerization temperature of 80-200°C and a polymerization time of 10-15 hours.

8. In step (3), the pre-sintering conditions include a pre-sintering temperature of 300-700°C and a pre-sintering time of 2-6 hours; The method of claim 4, wherein in step (4), the sintering conditions include a sintering temperature of 1000-1200°C and a sintering time of 4-10 hours.

9. The method described in claim 4, further comprising a step of nano-processing the product obtained by the grinding process described in step (4) in the presence of water to obtain a nano-level solid electrolyte material.

10. A solid electrolyte comprising the solid electrolyte material according to any one of claims 1 to 3, a polymer, and a sodium salt.

11. 11. A method for producing a solid electrolyte according to claim 10, said method comprising: (a) kneading a solid electrolyte material, a polymer, and a sodium salt to obtain a mixture; (b) heat-pressing the mixture.

12. The kneading conditions in step (a) are: a kneading temperature of 0.5-1.5T ｍ and T ｍ 12. The method of claim 11, wherein the temperature is the softening temperature of the polymer and the rotation speed is 300-500 rpm.

13. A positive electrode material comprising: a positive electrode active material; and a solid electrolyte material coated on a surface of the positive electrode active material, wherein the solid electrolyte material is the solid electrolyte material according to claim 1.

14. 14. The cathode material according to claim 13, wherein the mass ratio of the solid electrolyte material to the cathode active material is 0.05-1:

100.

15. 14. The positive electrode material according to claim 13, wherein when the positive electrode material is subjected to an acid-base titration treatment, a characteristic titration peak is found between pH=5 and pH=8.

16. A method for producing the cathode material of any one of claims 13 to 15, said method comprising: A method comprising the step of heat-treating a mixture containing a solid electrolyte material and a positive electrode active material at 300-750°C, wherein the solid electrolyte material is the solid electrolyte material according to any one of claims 1 to 3.

17. 17. The method of claim 16, wherein the temperature of the heat treatment is 400-750°C, and the time of the heat treatment is 2-12h.

18. A sodium ion battery, comprising the solid electrolyte material according to any one of claims 1 to 3 or the positive electrode material according to any one of claims 13 to 15.

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