Sodium-ion battery precursor, positive electrode material, preparation method therefor, and use thereof

Abstract

The present application relates to a sodium-ion battery precursor, a positive electrode material, a preparation method therefor, and a use thereof. The preparation method comprises the following steps: adding a mixed metal salt solution, a precipitant solution, a complexing agent solution, and an anion solution to a base solution in parallel, and performing a coprecipitation reaction to achieve a first target particle size; and continuing to add a ferrous sulfate solution, a diammonium hydrogen phosphate solution, the complexing agent solution, and the anion solution in parallel, performing a coprecipitation reaction to achieve a second target particle size, and performing solid-liquid separation, washing, and drying to obtain the sodium-ion battery precursor, wherein metal salts in the mixed metal salt solution include a nickel salt, a ferrous salt, a copper salt, a manganese salt, and a salt modified by means of doping; and the salt modified by means of doping includes a zirconium salt and / or a tungsten salt. By means of the use of the salt modified by means of doping and the anion solution, the sodium-ion battery precursor provided by the present application prevents an irreversible phase change, thereby improving the structural stability, so that the electrochemical performance of a corresponding positive electrode material is improved.

Description

Sodium battery precursor, cathode material, preparation method and application Technical Field

[0001] The present application belongs to the field of battery technology and relates to a precursor, and in particular to a sodium battery precursor, a positive electrode material, and a preparation method and application. Background Art

[0002] Lithium-ion batteries, with their high energy density and long cycle life, have been widely used in electronic devices. In recent years, lithium-ion batteries have been expanding into areas such as large-scale energy storage grids and electric vehicles. However, due to the limited and uneven distribution of lithium resources, the problem of high raw material costs has become increasingly prominent.

[0003] Similar to lithium-ion batteries, sodium-ion batteries have become a key development direction in the energy storage field due to their low cost, non-toxicity, and abundant and evenly distributed sodium resources. Like lithium-ion batteries, the energy storage performance of sodium-ion batteries is primarily influenced by the cathode material. Therefore, there is an urgent need to find a cathode material with high energy density, low cost, and long cycle life.

[0004] Cathode materials for sodium-ion batteries mainly include Prussian blue compounds, layered oxides, tunnel oxides, and polyanionic compounds. Among them, layered metal oxides have attracted widespread attention due to their high specific capacity, simple preparation process, and low production cost.

[0005] However, the cycle performance of sodium-ion batteries is not as good as that of lithium-ion batteries. The positive electrode materials of sodium-ion batteries need to be improved to improve the cycle performance of sodium-ion batteries. Therefore, it is necessary to provide a sodium battery precursor, positive electrode material, preparation method and application.

[0006] Summary of the Invention

[0007] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0008] The purpose of this application is to provide a sodium battery precursor, a positive electrode material, a preparation method and an application. The sodium battery precursor prevents the occurrence of irreversible phase change by doping modified salts and using anion solutions, thereby improving the structural stability and the electrochemical performance of the corresponding positive electrode material.

[0009] To achieve this goal, this application adopts the following technical solutions:

[0010] In a first aspect, the present application provides a method for preparing a sodium electrolyte precursor, the preparation method comprising the following steps:

[0011] Adding a mixed metal salt solution, a precipitant solution, a complexing agent solution and an anion solution concurrently to the base liquid, and performing a first coprecipitation reaction to a first target particle size;

[0012] The metal salts in the mixed metal salt solution include nickel salts, ferrous salts, copper salts, manganese salts and doping-modified salts; the doping-modified salts include zirconium salts and / or tungsten salts.

[0013] The preparation method of the sodium electrode precursor provided in the present application obtains a precursor of the first target particle size by co-precipitation. The zirconium salt used can improve the thermal stability of the material, and the tungsten salt can stabilize the structure under high pressure, further improving the cycle performance. The present application prevents the occurrence of irreversible phase change by using doped modified salts and anion solutions, thereby improving the structural stability and the electrochemical performance of the corresponding positive electrode material.

[0014] In one embodiment, the base solution is a combination of water, a precipitant solution and a complexing agent solution.

[0015] In one embodiment, the pH value of the base solution is 9-13.

[0016] In one embodiment, the concentration of the complexing agent in the base solution is 0.1-2 mol / L.

[0017] In one embodiment, the total concentration of nickel salt, ferrous salt, copper salt and manganese salt in the mixed metal salt solution is 0.5-5 mol / L.

[0018] In one embodiment, the concentration of the doping modified salt in the mixed metal salt solution is 0.1-0.5 mol / L.

[0019] In one embodiment, the nickel salt includes any one of nickel sulfate, nickel nitrate, or nickel chloride, or a combination of at least two thereof.

[0020] In one embodiment, the ferrous salt includes any one of ferrous sulfate, ferrous nitrate or ferrous chloride, or a combination of at least two thereof.

[0021] In one embodiment, the copper salt includes any one of copper sulfate, copper nitrate or copper chloride, or a combination of at least two thereof.

[0022] In one embodiment, the manganese salt includes any one of manganese sulfate, manganese nitrate, or manganese chloride, or a combination of at least two thereof.

[0023] In one embodiment, the zirconium salt includes any one of zirconium sulfate, zirconium nitrate, or zirconium chloride, or a combination of at least two thereof.

[0024] In one embodiment, the tungsten salt comprises sodium tungstate.

[0025] In one embodiment, the precipitant solution is a sodium hydroxide solution with a concentration of 2-15 mol / L.

[0026] In one embodiment, the complexing agent solution is aqueous ammonia with a concentration of 4-12 mol / L.

[0027] In one embodiment, the solute in the anion solution includes diammonium hydrogen phosphate and / or sodium silicate.

[0028] In one embodiment, the concentration of diammonium hydrogen phosphate in the anion solution is 0.1-0.5 mol / L.

[0029] In one embodiment, the concentration of sodium silicate in the anion solution is 0.1-0.5 mol / L.

[0030] In one embodiment, the flow rate of the mixed metal salt solution is 4-100 L / h.

[0031] In one embodiment, the flow rate of the complexing agent solution is 0.5-10 L / h.

[0032] In one embodiment, the flow rate of the anion solution is 0.1-5 L / h.

[0033] In one embodiment, the pH value of the first coprecipitation reaction is 7-13.

[0034] In one embodiment, the temperature of the first coprecipitation reaction is 40-80°C.

[0035] In one embodiment, the first target particle size is a particle size D50 of 5-8 μm.

[0036] In one embodiment, the preparation method further comprises a step of coprecipitation reaction to a first target particle size.

[0037] The ferrous solution, phosphate solution, complexing agent solution and anion solution are continuously added in parallel, a second coprecipitation reaction is carried out to a second target particle size, and the sodium electrode precursor is obtained through solid-liquid separation, washing and drying.

[0038] The present application utilizes the second coprecipitation reaction to coat the iron phosphate, thereby preventing the material from being corroded by the electrolyte, thereby improving the cycle performance of the corresponding positive electrode material.

[0039] In one embodiment, the solute in the ferrous solution includes ferrous sulfate and / or ferrous chloride.

[0040] In one embodiment, the solute in the phosphate solution includes diammonium hydrogen phosphate and / or ammonium dihydrogen phosphate.

[0041] In one embodiment, the concentration of the ferrous sulfate solution is 0.1-0.5 mol / L.

[0042] In one embodiment, the concentration of the diammonium hydrogen phosphate solution is 0.1-0.5 mol / L.

[0043] In one embodiment, the flow rate of the ferrous sulfate solution is 4-100 L / h.

[0044] In one embodiment, the flow rate of the diammonium hydrogen phosphate solution is 1-20 L / h.

[0045] In one embodiment, the pH value of the second co-precipitation reaction is 7-13.

[0046] In one embodiment, the temperature of the second co-precipitation reaction is 40-80°C.

[0047] In one embodiment, the second target particle size is a particle size D50 of 10-15 μm.

[0048] In a second aspect, the present application provides a sodium battery precursor, which is prepared by the preparation method described in the first aspect.

[0049] In a third aspect, the present application provides a method for preparing a positive electrode material, the preparation method comprising the following steps:

[0050] The sodium source is mixed with the sodium electrode precursor described in the second aspect, and sintered to obtain the positive electrode material.

[0051] In a fourth aspect, the present application provides a positive electrode material, which is prepared using the preparation method described in the third aspect.

[0052] In a fifth aspect, the present application provides an electrode, which includes the sodium electrode precursor described in the second aspect, or includes the positive electrode material described in the fourth aspect.

[0053] Compared with the prior art, this application has the following beneficial effects:

[0054] The preparation method of the sodium electrode precursor provided in the present application obtains a precursor of the first target particle size by co-precipitation. The zirconium salt used can improve the thermal stability of the material, and the tungsten salt can stabilize the structure of the material under high pressure. The present application prevents the occurrence of irreversible phase change by using doped modified salts and anion solutions, thereby improving the structural stability and the electrochemical performance of the corresponding positive electrode material.

[0055] Still other aspects will become apparent upon reading and understanding the accompanying drawings and detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The accompanying drawings are used to provide a further understanding of the technical solution of this article and constitute a part of the specification. Together with the embodiments of this application, they are used to explain the technical solution of this article and do not constitute a limitation on the technical solution of this article.

[0057] FIG1 is a schematic structural diagram of the sodium electrolyte precursor provided in Example 6. DETAILED DESCRIPTION

[0058] The technical solution of the present application is further described below through specific implementation methods. Those skilled in the art should understand that the embodiments are only used to help understand the present application and should not be regarded as specific limitations of the present application.

[0059] An embodiment of the present application provides a method for preparing a sodium electrolyte precursor, the method comprising the following steps:

[0060] Adding a mixed metal salt solution, a precipitant solution, a complexing agent solution and an anion solution concurrently to the base liquid, and performing a first coprecipitation reaction to a first target particle size;

[0061] The metal salts in the mixed metal salt solution include nickel salts, ferrous salts, copper salts, manganese salts and doping-modified salts; the doping-modified salts include zirconium salts and / or tungsten salts.

[0062] The preparation method of the sodium electrode precursor provided in the present application obtains a precursor of the first target particle size by co-precipitation. The zirconium salt used can improve the thermal stability of the material, and the tungsten salt can stabilize the structure of the material under high pressure. The present application prevents the occurrence of irreversible phase change by using doped modified salts and anion solutions, thereby improving the structural stability and the electrochemical performance of the corresponding positive electrode material.

[0063] In certain embodiments, the base solution is a combination of water, a precipitant solution, and a complexing agent solution.

[0064] In some embodiments, the pH value of the base solution is 9-13, for example, 9, 10, 11, 12 or 13, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0065] In some embodiments, the concentration of the complexing agent in the base solution is 0.1-2 mol / L, for example, it can be 0.1 mol / L, 0.5 mol / L, 0.8 mol / L, 1 mol / L, 1.2 mol / L, 1.5 mol / L, 1.8 mol / L or 2 mol / L, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0066] In certain embodiments, the total concentration of nickel salt, ferrous salt, copper salt and manganese salt in the mixed metal salt solution is 0.5-5 mol / L, for example, it can be 0.5 mol / L, 1 mol / L, 2 mol / L, 3 mol / L, 4 mol / L or 5 mol / L, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0067] Exemplarily, in the mixed metal salt solution, the molar ratio of nickel element, ferrous element, copper element and manganese element is 1:(0.6-1):(0.8-1.2):(0.8-1.2), for example, it can be 1:0.6:0.8:0.8, 1:1:1.2:1.2, 1:0.8:1:1, 1:1:0.8:1.2 or 1:0.6:1.2:0.8, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0068] In some embodiments, the concentration of the doped modified salt in the mixed metal salt solution is 0.1-0.5 mol / L, for example, it can be 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L or 0.5 mol / L, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0069] In certain embodiments, the nickel salt includes any one or a combination of at least two of nickel sulfate, nickel nitrate, or nickel chloride. Typical but non-limiting combinations include a combination of nickel sulfate and nickel nitrate, a combination of nickel nitrate and nickel chloride, a combination of nickel sulfate and nickel chloride, or a combination of nickel sulfate, nickel nitrate, and nickel chloride.

[0070] In certain embodiments, the ferrous salt includes any one or a combination of at least two of ferrous sulfate, ferrous nitrate or ferrous chloride. Typical but non-limiting combinations include a combination of ferrous sulfate and ferrous nitrate, a combination of ferrous nitrate and ferrous chloride, a combination of ferrous sulfate and ferrous chloride, or a combination of ferrous sulfate, ferrous nitrate and ferrous chloride.

[0071] In certain embodiments, the copper salt includes any one or a combination of at least two of copper sulfate, copper nitrate, or copper chloride. Typical but non-limiting combinations include a combination of copper sulfate and copper nitrate, a combination of copper nitrate and copper chloride, a combination of copper sulfate and copper chloride, or a combination of copper sulfate, copper nitrate, and copper chloride.

[0072] In certain embodiments, the manganese salt includes any one or a combination of at least two of manganese sulfate, manganese nitrate, or manganese chloride. Typical but non-limiting combinations include a combination of manganese sulfate and manganese nitrate, a combination of manganese nitrate and manganese chloride, a combination of manganese sulfate and manganese chloride, or a combination of manganese sulfate, manganese nitrate, and manganese chloride.

[0073] In certain embodiments, the zirconium salt includes any one or a combination of at least two of zirconium sulfate, zirconium nitrate, or zirconium chloride. Typical but non-limiting combinations include a combination of zirconium sulfate and zirconium nitrate, a combination of zirconium nitrate and zirconium chloride, a combination of zirconium sulfate and zirconium chloride, or a combination of zirconium sulfate, zirconium nitrate, and zirconium chloride.

[0074] In certain embodiments, the tungsten salt includes sodium tungstate.

[0075] In certain embodiments, the precipitant solution is a sodium hydroxide solution with a concentration of 2-15 mol / L, for example, 2 mol / L, 5 mol / L, 6 mol / L, 8 mol / L, 10 mol / L, 12 mol / L or 15 mol / L, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0076] In some embodiments, the complexing agent solution is aqueous ammonia with a concentration of 4-12 mol / L, for example, 4 mol / L, 5 mol / L, 8 mol / L, 10 mol / L or 12 mol / L, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0077] In certain embodiments, the solute in the anion solution includes diammonium hydrogen phosphate and / or sodium silicate, optionally a combination of diammonium hydrogen phosphate and sodium silicate.

[0078] The present application improves the cycle stability of the obtained sodium electrode precursor by using an anion solution containing diammonium hydrogen phosphate and / or sodium silicate and coordinating it with a doping modified salt.

[0079] In certain embodiments, the concentration of diammonium hydrogen phosphate in the anion solution is 0.1-0.5 mol / L, for example, 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L or 0.5 mol / L, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0080] In some embodiments, the concentration of sodium silicate in the anion solution is 0.1-0.5 mol / L, for example, 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L or 0.5 mol / L, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0081] In certain embodiments, the flow rate of the mixed metal salt solution is 4-100 L / h, for example, 4 L / h, 10 L / h, 20 L / h, 40 L / h, 50 L / h, 60 L / h, 80 L / h or 100 L / h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0082] In certain embodiments, the flow rate of the complexing agent solution is 0.5-10 L / h, for example, 0.5 L / h, 1 L / h, 3 L / h, 5 L / h, 6 L / h, 8 L / h or 10 L / h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0083] In some embodiments, the flow rate of the anion solution is 0.1-5 L / h, for example, it can be 0.1 L / h, 0.5 L / h, 1 L / h, 2 L / h, 3 L / h, 4 L / h or 5 L / h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0084] This application does not limit the flow rate of the precipitant solution during the first coprecipitation reaction, as long as the pH value of the first coprecipitation reaction can meet the process requirements.

[0085] In certain embodiments, the pH value of the first coprecipitation reaction is 7-13, for example, 7, 8, 9, 10, 12 or 13, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0086] In certain embodiments, the temperature of the first coprecipitation reaction is 40-80°C, for example, 40°C, 50°C, 60°C, 70°C or 80°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0087] In some embodiments, the first target particle size is a particle size D50 of 5-8 μm, for example, 5 μm, 6 μm, 7 μm or 8 μm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0088] In certain embodiments, the preparation method further comprises a step of co-precipitation reaction to a first target particle size.

[0089] The ferrous solution, phosphate solution, complexing agent solution and anion solution are continuously added in parallel, a second coprecipitation reaction is carried out to a second target particle size, and the sodium electrode precursor is obtained through solid-liquid separation, washing and drying.

[0090] The present application utilizes the second coprecipitation reaction to coat the iron phosphate, thereby preventing the material from being corroded by the electrolyte, thereby improving the cycle performance of the corresponding positive electrode material.

[0091] In the present application, when the second coprecipitation reaction is carried out, the concentration and flow rate of the complexing agent solution and the anion solution are the same as those when the first coprecipitation reaction is carried out.

[0092] In one embodiment, the solute in the ferrous solution includes ferrous sulfate and / or ferrous chloride.

[0093] In one embodiment, the solute in the phosphate solution includes diammonium hydrogen phosphate and / or ammonium dihydrogen phosphate.

[0094] In certain embodiments, the concentration of the ferrous sulfate solution is 0.1-0.5 mol / L, for example, 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L or 0.5 mol / L, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0095] In certain embodiments, the concentration of the diammonium hydrogen phosphate solution is 0.1-0.5 mol / L, for example, 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L or 0.5 mol / L, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0096] In certain embodiments, the flow rate of the ferrous sulfate solution is 4-100 L / h, for example, 4 L / h, 10 L / h, 20 L / h, 40 L / h, 50 L / h, 60 L / h, 80 L / h or 100 L / h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0097] In certain embodiments, the flow rate of the diammonium hydrogen phosphate solution is 1-20 L / h, for example, 1 L / h, 3 L / h, 5 L / h, 8 L / h, 10 L / h, 12 L / h, 15 L / h, 18 L / h or 20 L / h, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0098] In certain embodiments, the pH value of the second coprecipitation reaction is 7-13, for example, 7, 8, 9, 10, 12 or 13, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0099] In certain embodiments, the temperature of the second coprecipitation reaction is 40-80°C, for example, 40°C, 50°C, 60°C, 70°C or 80°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0100] In some embodiments, the second target particle size is a particle size D50 of 10-15 μm, for example, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm or 15 μm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0101] A certain embodiment of the present application provides a sodium battery precursor, which is prepared by the preparation method in certain embodiments.

[0102] A certain embodiment of the present application provides a method for preparing a positive electrode material, the preparation method comprising the following steps:

[0103] A sodium source and a sodium electrode precursor are mixed and sintered to obtain the positive electrode material.

[0104] Exemplarily, the sintering is carried out in a tube furnace in an oxygen atmosphere at a temperature of 700-1200° C. for 10-25 hours.

[0105] The sintering temperature in this application is 700-1200°C, for example, it can be 700°C, 800°C, 900°C, 1000°C, 1100°C or 1200°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0106] The sintering time in this application is 10-25 hours, for example, it can be 10 hours, 12 hours, 15 hours, 18 hours, 20 hours, 21 hours or 25 hours, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0107] A certain embodiment of the present application provides a positive electrode material, which is prepared using the preparation method described in a certain embodiment.

[0108] A certain embodiment of the present application provides an electrode, which includes the sodium electrode precursor described in a certain embodiment, or includes the positive electrode material described in a certain embodiment.

[0109] The methods of solid-liquid separation, washing and drying described in this application are conventional methods in the art and are not specifically limited in this application, as long as the effects of solid-liquid separation, washing and drying can be achieved.

[0110] Example 1

[0111] This embodiment provides a method for preparing a sodium electrolyte precursor, the preparation method comprising the following steps:

[0112] A mixed metal salt solution, a 10 mol / L sodium hydroxide solution, an 8 mol / L ammonia solution, and an anion solution are added concurrently to the base liquid, and a first coprecipitation reaction is performed to a first target particle size;

[0113] The metal salts in the mixed metal salt solution include nickel sulfate, ferrous sulfate, copper sulfate, manganese sulfate and a doping modified salt; the doping modified salt includes zirconium sulfate; the total concentration of nickel sulfate, ferrous sulfate, copper sulfate and manganese sulfate is 3 mol / L, and the concentration of zirconium sulfate is 0.3 mol / L;

[0114] In the mixed metal salt solution, the molar ratio of nickel, ferrous, copper and manganese is 1:0.8:1:1;

[0115] The base liquid is a combination of water, sodium hydroxide solution and ammonia water; the pH value of the base liquid is 10, and the concentration of ammonia water in the base liquid is 1 mol / L;

[0116] The solutes in the anion solution include diammonium hydrogen sulfate and sodium silicate, wherein the concentration of diammonium hydrogen phosphate is 0.3 mol / L, and the concentration of sodium silicate is 0.3 mol / L;

[0117] The flow rate of the mixed metal salt solution is 50 L / h, the flow rate of the ammonia water is 5 L / h, and the flow rate of the anion solution is 3 L / h; the pH value of the first coprecipitation reaction is 10, and the temperature is 50°C; the first target particle size is a particle size D50 of 6 μm.

[0118] Example 2

[0119] This embodiment provides a method for preparing a sodium electrolyte precursor, the preparation method comprising the following steps:

[0120] A mixed metal salt solution, a 2 mol / L sodium hydroxide solution, a 4 mol / L ammonia solution, and an anion solution are added concurrently to the base liquid, and a first coprecipitation reaction is performed to a first target particle size;

[0121] The metal salts in the mixed metal salt solution include nickel sulfate, ferrous sulfate, copper sulfate, manganese sulfate and a doping modified salt; the doping modified salt includes zirconium sulfate; the total concentration of nickel sulfate, ferrous sulfate, copper sulfate and manganese sulfate is 0.5 mol / L, and the concentration of zirconium sulfate is 0.1 mol / L;

[0122] In the mixed metal salt solution, the molar ratio of nickel, ferrous, copper and manganese is 1:0.8:1:1;

[0123] The base liquid is a combination of water, sodium hydroxide solution and ammonia water; the pH value of the base liquid is 9, and the concentration of ammonia water in the base liquid is 0.1 mol / L;

[0124] The solutes in the anion solution include diammonium hydrogen sulfate and sodium silicate, wherein the concentration of diammonium hydrogen phosphate is 0.1 mol / L, and the concentration of sodium silicate is 0.1 mol / L;

[0125] The flow rate of the mixed metal salt solution is 4 L / h, the flow rate of the ammonia water is 0.5 L / h, and the flow rate of the anion solution is 0.1 L / h; the pH value of the first coprecipitation reaction is 7, and the temperature is 40°C; the first target particle size is a particle size D50 of 5 μm.

[0126] Example 3

[0127] This embodiment provides a method for preparing a sodium electrolyte precursor, the preparation method comprising the following steps:

[0128] A mixed metal salt solution, a 15 mol / L sodium hydroxide solution, a 12 mol / L ammonia solution, and an anion solution are added concurrently to the base liquid, and a first coprecipitation reaction is performed to a first target particle size;

[0129] The metal salts in the mixed metal salt solution include nickel sulfate, ferrous sulfate, copper sulfate, manganese sulfate and a doping modified salt; the doping modified salt includes zirconium sulfate; the total concentration of nickel sulfate, ferrous sulfate, copper sulfate and manganese sulfate is 5 mol / L, and the concentration of zirconium sulfate is 0.5 mol / L;

[0130] In the mixed metal salt solution, the molar ratio of nickel, ferrous, copper and manganese is 1:0.8:1:1;

[0131] The base liquid is a combination of water, sodium hydroxide solution and ammonia water; the pH value of the base liquid is 13, and the concentration of ammonia water in the base liquid is 2 mol / L;

[0132] The solutes in the anion solution include diammonium hydrogen sulfate and sodium silicate, wherein the concentration of diammonium hydrogen phosphate is 0.5 mol / L, and the concentration of sodium silicate is 0.5 mol / L;

[0133] The flow rate of the mixed metal salt solution is 100 L / h, the flow rate of the ammonia solution is 10 L / h, and the flow rate of the anion solution is 5 L / h; the pH value of the first coprecipitation reaction is 13, and the temperature is 80°C; the first target particle size is a particle size D50 of 8 μm.

[0134] Example 4

[0135] This embodiment provides a method for preparing a sodium electrolyte precursor, the preparation method comprising the following steps:

[0136] A mixed metal salt solution, a 10 mol / L sodium hydroxide solution, an 8 mol / L ammonia solution, and an anion solution are added concurrently to the base liquid, and a first coprecipitation reaction is performed to a first target particle size;

[0137] The metal salts in the mixed metal salt solution include nickel sulfate, ferrous sulfate, copper sulfate, manganese sulfate, and a doping modified salt; the doping modified salt includes sodium tungstate; the total concentration of nickel sulfate, ferrous sulfate, copper sulfate, and manganese sulfate is 3 mol / L, and the concentration of sodium tungstate is 0.3 mol / L;

[0138] In the mixed metal salt solution, the molar ratio of nickel, ferrous, copper and manganese is 1:0.8:1:1;

[0139] The base liquid is a combination of water, sodium hydroxide solution and ammonia water; the pH value of the base liquid is 10, and the concentration of ammonia water in the base liquid is 1 mol / L;

[0140] The solutes in the anion solution include diammonium hydrogen sulfate and sodium silicate, wherein the concentration of diammonium hydrogen phosphate is 0.3 mol / L, and the concentration of sodium silicate is 0.3 mol / L;

[0141] The flow rate of the mixed metal salt solution is 50 L / h, the flow rate of the ammonia water is 5 L / h, and the flow rate of the anion solution is 3 L / h; the pH value of the first coprecipitation reaction is 10, and the temperature is 50°C; the first target particle size is a particle size D50 of 6 μm.

[0142] Example 5

[0143] This embodiment provides a method for preparing a sodium electrolyte precursor, the preparation method comprising the following steps:

[0144] A mixed metal salt solution, a 10 mol / L sodium hydroxide solution, an 8 mol / L ammonia solution, and an anion solution are added concurrently to the base liquid, and a first coprecipitation reaction is performed to a first target particle size;

[0145] The metal salts in the mixed metal salt solution include nickel sulfate, ferrous sulfate, copper sulfate, manganese sulfate, and a doping modified salt; the doping modified salt includes zirconium sulfate and sodium tungstate; the total concentration of nickel sulfate, ferrous sulfate, copper sulfate, and manganese sulfate is 3 mol / L, the concentration of zirconium sulfate is 0.15 mol / L, and the concentration of sodium tungstate is 0.15 mol / L;

[0146] In the mixed metal salt solution, the molar ratio of nickel, ferrous, copper and manganese is 1:0.8:1:1;

[0147] The base liquid is a combination of water, sodium hydroxide solution and ammonia water; the pH value of the base liquid is 10, and the concentration of ammonia water in the base liquid is 1 mol / L;

[0148] The solutes in the anion solution include diammonium hydrogen sulfate and sodium silicate, wherein the concentration of diammonium hydrogen phosphate is 0.3 mol / L, and the concentration of sodium silicate is 0.3 mol / L;

[0149] The flow rate of the mixed metal salt solution is 50 L / h, the flow rate of the ammonia water is 5 L / h, and the flow rate of the anion solution is 3 L / h; the pH value of the first coprecipitation reaction is 10, and the temperature is 50°C; the first target particle size is a particle size D50 of 6 μm.

[0150] Example 6

[0151] This embodiment provides a method for preparing a sodium electrolyte precursor, the preparation method comprising the following steps:

[0152] (1) adding a mixed metal salt solution, a 10 mol / L sodium hydroxide solution, an 8 mol / L ammonia solution, and an anion solution to the base liquid in parallel, and performing a first coprecipitation reaction to a first target particle size;

[0153] The metal salts in the mixed metal salt solution include nickel sulfate, ferrous sulfate, copper sulfate, manganese sulfate, and a doping modified salt; the doping modified salt includes zirconium sulfate and sodium tungstate; the total concentration of nickel sulfate, ferrous sulfate, copper sulfate, and manganese sulfate is 3 mol / L, the concentration of zirconium sulfate is 0.15 mol / L, and the concentration of sodium tungstate is 0.15 mol / L;

[0154] In the mixed metal salt solution, the molar ratio of nickel, ferrous, copper and manganese is 1:0.8:1:1;

[0155] The base liquid is a combination of water, sodium hydroxide solution and ammonia water; the pH value of the base liquid is 10, and the concentration of ammonia water in the base liquid is 1 mol / L;

[0156] The solutes in the anion solution include diammonium hydrogen sulfate and sodium silicate, wherein the concentration of diammonium hydrogen phosphate is 0.3 mol / L, and the concentration of sodium silicate is 0.3 mol / L;

[0157] The flow rate of the mixed metal salt solution is 50 L / h, the flow rate of the ammonia solution is 5 L / h, and the flow rate of the anion solution is 3 L / h; the pH value of the first coprecipitation reaction is 10, and the temperature is 50° C.; the first target particle size is a particle size D50 of 6 μm;

[0158] (2) continuing to add 0.3 mol / L ferrous sulfate solution, 0.3 mol / L diammonium hydrogen phosphate solution, 8 mol / L ammonia water and anion solution in parallel, performing a second coprecipitation reaction to a second target particle size, and performing solid-liquid separation, washing and drying to obtain the sodium electrode precursor;

[0159] The flow rate of the ferrous sulfate solution is 50 L / h, the flow rate of the diammonium hydrogen phosphate solution is 10 L / h, and the flow rates of the ammonia water and the anion solution are the same as those in the first coprecipitation reaction; the pH value of the second coprecipitation reaction is 10, and the temperature is 50°C; the second target particle size is a particle size D50 of 12 μm.

[0160] The SEM image of the sodium electrolyte precursor obtained in this example is shown in FIG1 .

[0161] Example 7

[0162] This embodiment provides a method for preparing a sodium electrolyte precursor, the preparation method comprising the following steps:

[0163] (1) adding a mixed metal salt solution, a 10 mol / L sodium hydroxide solution, an 8 mol / L ammonia solution, and an anion solution to the base liquid in parallel, and performing a first coprecipitation reaction to a first target particle size;

[0164] The metal salts in the mixed metal salt solution include nickel sulfate, ferrous sulfate, copper sulfate, manganese sulfate and a doping modified salt; the doping modified salt includes zirconium sulfate; the total concentration of nickel sulfate, ferrous sulfate, copper sulfate and manganese sulfate is 0.5 mol / L, and the concentration of zirconium sulfate is 0.1 mol / L;

[0165] In the mixed metal salt solution, the molar ratio of nickel, ferrous, copper and manganese is 1:0.8:1:1;

[0166] The base liquid is a combination of water, sodium hydroxide solution and ammonia water; the pH value of the base liquid is 9, and the concentration of ammonia water in the base liquid is 0.1 mol / L;

[0167] The solutes in the anion solution include diammonium hydrogen sulfate and sodium silicate, wherein the concentration of diammonium hydrogen phosphate is 0.1 mol / L, and the concentration of sodium silicate is 0.1 mol / L;

[0168] The flow rate of the mixed metal salt solution is 4 L / h, the flow rate of the ammonia solution is 0.5 L / h, and the flow rate of the anion solution is 0.1 L / h; the pH value of the first coprecipitation reaction is 7, and the temperature is 40° C.; the first target particle size is a particle size D50 of 5 μm;

[0169] (2) continuing to add 0.1 mol / L ferrous sulfate solution, 0.1 mol / L diammonium hydrogen phosphate solution, 8 mol / L ammonia water and anion solution in parallel, performing a second coprecipitation reaction to a second target particle size, and performing solid-liquid separation, washing and drying to obtain the sodium electrode precursor;

[0170] The flow rate of the ferrous sulfate solution is 4 L / h, the flow rate of the diammonium hydrogen phosphate solution is 1 L / h, and the flow rates of the ammonia water and the anion solution are the same as those in the first coprecipitation reaction; the pH value of the second coprecipitation reaction is 10, and the temperature is 50°C; the second target particle size is a particle size D50 of 10 μm.

[0171] Example 8

[0172] This embodiment provides a method for preparing a sodium electrolyte precursor, the preparation method comprising the following steps:

[0173] (1) adding a mixed metal salt solution, a 10 mol / L sodium hydroxide solution, an 8 mol / L ammonia solution, and an anion solution to the base liquid in parallel, and performing a first coprecipitation reaction to a first target particle size;

[0174] The metal salts in the mixed metal salt solution include nickel sulfate, ferrous sulfate, copper sulfate, manganese sulfate and a doping modified salt; the doping modified salt includes zirconium sulfate; the total concentration of nickel sulfate, ferrous sulfate, copper sulfate and manganese sulfate is 5 mol / L, and the concentration of zirconium sulfate is 0.5 mol / L;

[0175] In the mixed metal salt solution, the molar ratio of nickel, ferrous, copper and manganese is 1:0.8:1:1;

[0176] The base liquid is a combination of water, sodium hydroxide solution and ammonia water; the pH value of the base liquid is 13, and the concentration of ammonia water in the base liquid is 2 mol / L;

[0177] The solutes in the anion solution include diammonium hydrogen sulfate and sodium silicate, wherein the concentration of diammonium hydrogen phosphate is 0.5 mol / L, and the concentration of sodium silicate is 0.5 mol / L;

[0178] The flow rate of the mixed metal salt solution is 100 L / h, the flow rate of the ammonia solution is 10 L / h, and the flow rate of the anion solution is 5 L / h; the pH value of the first coprecipitation reaction is 13, and the temperature is 80° C.; the first target particle size is a particle size D50 of 8 μm;

[0179] (2) continuing to add 0.5 mol / L ferrous sulfate solution, 0.5 mol / L diammonium hydrogen phosphate solution, 8 mol / L ammonia water and anion solution in parallel, performing a second coprecipitation reaction to a second target particle size, and performing solid-liquid separation, washing and drying to obtain the sodium electrode precursor;

[0180] The flow rate of the ferrous sulfate solution is 100 L / h, the flow rate of the diammonium hydrogen phosphate solution is 20 L / h, and the flow rates of the ammonia water and the anion solution are the same as those in the first coprecipitation reaction; the pH value of the second coprecipitation reaction is 13, and the temperature is 80°C; the second target particle size is a particle size D50 of 15 μm.

[0181] Comparative Example 1

[0182] This comparative example provides a method for preparing a sodium electrolyte precursor, which comprises the following steps:

[0183] (1) adding a mixed metal salt solution, a 10 mol / L sodium hydroxide solution, an 8 mol / L ammonia solution, and an anion solution to the base liquid in parallel, and performing a first coprecipitation reaction to a first target particle size;

[0184] The metal salts in the mixed metal salt solution include nickel sulfate, ferrous sulfate, copper sulfate, manganese sulfate, and a doping modified salt; the doping modified salt includes zirconium sulfate and sodium molybdate; the total concentration of nickel sulfate, ferrous sulfate, copper sulfate, and manganese sulfate is 3 mol / L, the concentration of zirconium sulfate is 0.15 mol / L, and the concentration of sodium molybdate is 0.15 mol / L;

[0185] In the mixed metal salt solution, the molar ratio of nickel, ferrous, copper and manganese is 1:0.8:1:1;

[0186] The base liquid is a combination of water, sodium hydroxide solution and ammonia water; the pH value of the base liquid is 10, and the concentration of ammonia water in the base liquid is 1 mol / L;

[0187] The solutes in the anion solution include diammonium hydrogen sulfate and sodium silicate, wherein the concentration of diammonium hydrogen phosphate is 0.3 mol / L, and the concentration of sodium silicate is 0.3 mol / L;

[0188] The flow rate of the mixed metal salt solution is 50 L / h, the flow rate of the ammonia solution is 5 L / h, and the flow rate of the anion solution is 3 L / h; the pH value of the first coprecipitation reaction is 10, and the temperature is 50° C.; the first target particle size is a particle size D50 of 6 μm;

[0189] (2) continuing to add 0.3 mol / L ferrous sulfate solution, 0.3 mol / L diammonium hydrogen phosphate solution, 8 mol / L ammonia water and anion solution in parallel, performing a second coprecipitation reaction to a second target particle size, and performing solid-liquid separation, washing and drying to obtain the sodium electrode precursor;

[0190] The flow rate of the ferrous sulfate solution is 50 L / h, the flow rate of the diammonium hydrogen phosphate solution is 10 L / h, and the flow rates of the ammonia water and the anion solution are the same as those in the first coprecipitation reaction; the pH value of the second coprecipitation reaction is 10, and the temperature is 50°C; the second target particle size is a particle size D50 of 12 μm.

[0191] Comparative Example 2

[0192] This comparative example provides a method for preparing a sodium electrolyte precursor, which comprises the following steps:

[0193] (1) adding a mixed metal salt solution, a 10 mol / L sodium hydroxide solution, an 8 mol / L ammonia solution, and an anion solution to the base liquid in parallel, and performing a first coprecipitation reaction to a first target particle size;

[0194] The metal salts in the mixed metal salt solution include nickel sulfate, ferrous sulfate, copper sulfate and manganese sulfate; the total concentration of nickel sulfate, ferrous sulfate, copper sulfate and manganese sulfate is 3 mol / L;

[0195] In the mixed metal salt solution, the molar ratio of nickel, ferrous, copper and manganese is 1:0.8:1:1;

[0196] The base liquid is a combination of water, sodium hydroxide solution and ammonia water; the pH value of the base liquid is 10, and the concentration of ammonia water in the base liquid is 1 mol / L;

[0197] The solutes in the anion solution include diammonium hydrogen sulfate and sodium silicate, wherein the concentration of diammonium hydrogen phosphate is 0.3 mol / L, and the concentration of sodium silicate is 0.3 mol / L;

[0198] The flow rate of the mixed metal salt solution is 50 L / h, the flow rate of the ammonia solution is 5 L / h, and the flow rate of the anion solution is 3 L / h; the pH value of the first coprecipitation reaction is 10, and the temperature is 50° C.; the first target particle size is a particle size D50 of 6 μm;

[0199] (2) continuing to add 0.3 mol / Lmol / L ferrous sulfate solution, 0.3 mol / Lmol / L diammonium hydrogen phosphate solution, 8 mol / L ammonia water and anion solution in parallel, performing a second coprecipitation reaction to a second target particle size, and performing solid-liquid separation, washing and drying to obtain the sodium electrode precursor;

[0200] The flow rate of the ferrous sulfate solution is 50 L / h, the flow rate of the diammonium hydrogen phosphate solution is 10 L / h, and the flow rates of the ammonia water and the anion solution are the same as those in the first coprecipitation reaction; the pH value of the second coprecipitation reaction is 10, and the temperature is 50°C; the second target particle size is a particle size D50 of 12 μm.

[0201] Comparative Example 3

[0202] This comparative example provides a method for preparing a sodium electrolyte precursor, which comprises the following steps:

[0203] (1) adding a mixed metal salt solution, a 10 mol / L sodium hydroxide solution, and an 8 mol / L ammonia solution concurrently to the base liquid, and performing a first coprecipitation reaction to a first target particle size;

[0204] The metal salts in the mixed metal salt solution include nickel sulfate, ferrous sulfate, copper sulfate, manganese sulfate, and a doping modified salt; the doping modified salt includes zirconium sulfate and sodium tungstate; the total concentration of nickel sulfate, ferrous sulfate, copper sulfate, and manganese sulfate is 3 mol / L; the concentration of zirconium sulfate is 0.15 mol / L, and the concentration of sodium tungstate is 0.15 mol / L;

[0205] In the mixed metal salt solution, the molar ratio of nickel, ferrous, copper and manganese is 1:0.8:1:1;

[0206] The base liquid is a combination of water, sodium hydroxide solution and ammonia water; the pH value of the base liquid is 10, and the concentration of ammonia water in the base liquid is 1 mol / L;

[0207] The flow rate of the mixed metal salt solution is 50 L / h, and the flow rate of the ammonia water is 5 L / h. The pH value of the first coprecipitation reaction is 10, and the temperature is 50° C. The first target particle size is a particle size D50 of 6 μm;

[0208] (2) continuing to add 0.3 mol / L ferrous sulfate solution, 0.3 mol / L diammonium hydrogen phosphate solution and 8 mol / L ammonia water in parallel, performing a second coprecipitation reaction to a second target particle size, and performing solid-liquid separation, washing and drying to obtain the sodium electrode precursor;

[0209] The flow rate of the ferrous sulfate solution is 50 L / h, the flow rate of the diammonium hydrogen phosphate solution is 10 L / h, and the flow rate of the ammonia water is the same as that in the first coprecipitation reaction; the pH value of the second coprecipitation reaction is 10, and the temperature is 50°C; the second target particle size is a particle size D50 of 12 μm.

[0210] Application Example 1

[0211] This application example provides a method for preparing a positive electrode material, the preparation method comprising the following steps:

[0212] Sodium carbonate was mixed with the sodium electrode precursor obtained in Example 1, and the mixture was roasted in a tube furnace under oxygen flow to obtain a positive electrode material;

[0213] The sintering temperature is 700℃ and the time is 10h;

[0214] The molar ratio of sodium in sodium carbonate to sodium electrolytic precursor is 1.02:1.

[0215] Application Example 2

[0216] This application example provides a method for preparing a positive electrode material, the preparation method comprising the following steps:

[0217] Sodium carbonate was mixed with the sodium electrode precursor obtained in Example 2, and the mixture was roasted in a tube furnace under oxygen flow to obtain a positive electrode material;

[0218] The sintering temperature is 700℃ and the time is 10h;

[0219] The molar ratio of sodium in sodium carbonate to sodium electrolytic precursor is 1.02:1.

[0220] Application Example 3

[0221] This application example provides a method for preparing a positive electrode material, the preparation method comprising the following steps:

[0222] Sodium carbonate was mixed with the sodium electrode precursor obtained in Example 3, and the mixture was roasted in a tube furnace under oxygen flow to obtain a positive electrode material;

[0223] The sintering temperature is 700℃ and the time is 10h;

[0224] The molar ratio of sodium in sodium carbonate to sodium electrolytic precursor is 1.02:1.

[0225] Application Example 4

[0226] This application example provides a method for preparing a positive electrode material, the preparation method comprising the following steps:

[0227] Sodium carbonate was mixed with the sodium electrode precursor obtained in Example 4, and the mixture was roasted in a tube furnace under oxygen flow to obtain a positive electrode material;

[0228] The sintering temperature is 700℃ and the time is 10h;

[0229] The molar ratio of sodium in sodium carbonate to sodium electrolytic precursor is 1.02:1.

[0230] Application Example 5

[0231] This application example provides a method for preparing a positive electrode material, the preparation method comprising the following steps:

[0232] Sodium carbonate was mixed with the sodium electrode precursor obtained in Example 5, and the mixture was roasted in a tube furnace under oxygen flow to obtain a positive electrode material;

[0233] The sintering temperature is 700℃ and the time is 10h;

[0234] The molar ratio of sodium in sodium carbonate to sodium electrolytic precursor is 1.02:1.

[0235] Application Example 6

[0236] This application example provides a method for preparing a positive electrode material, the preparation method comprising the following steps:

[0237] Sodium carbonate was mixed with the sodium electrode precursor obtained in Example 6, and the mixture was roasted in a tube furnace under oxygen flow to obtain a positive electrode material;

[0238] The sintering temperature is 700℃ and the time is 10h;

[0239] The molar ratio of sodium in sodium carbonate to sodium electrolytic precursor is 1.02:1.

[0240] Application Example 7

[0241] This application example provides a method for preparing a positive electrode material, the preparation method comprising the following steps:

[0242] Sodium carbonate was mixed with the sodium electrode precursor obtained in Example 7, and the mixture was roasted in a tube furnace under oxygen flow to obtain a positive electrode material;

[0243] The sintering temperature is 700℃ and the time is 10h;

[0244] The molar ratio of sodium in sodium carbonate to sodium electrolytic precursor is 1.02:1.

[0245] Application Example 8

[0246] This application example provides a method for preparing a positive electrode material, the preparation method comprising the following steps:

[0247] Sodium carbonate was mixed with the sodium electrode precursor obtained in Example 8, and the mixture was roasted in a tube furnace under oxygen flow to obtain a positive electrode material;

[0248] The sintering temperature is 700℃ and the time is 10h;

[0249] The molar ratio of sodium in sodium carbonate to sodium electrolytic precursor is 1.02:1.

[0250] Comparative Application Example 1

[0251] This comparative application example provides a method for preparing a positive electrode material, the preparation method comprising the following steps:

[0252] Sodium carbonate was mixed with the sodium electrode precursor obtained in Comparative Example 1, and the mixture was roasted in a tube furnace under oxygen flow to obtain a positive electrode material;

[0253] The sintering temperature is 700℃ and the time is 10h;

[0254] The molar ratio of sodium in sodium carbonate to sodium electrolytic precursor is 1.02:1.

[0255] Comparative Application Example 2

[0256] This comparative application example provides a method for preparing a positive electrode material, the preparation method comprising the following steps:

[0257] Sodium carbonate was mixed with the sodium electrode precursor obtained in Comparative Example 2, and the mixture was roasted in a tube furnace under oxygen flow to obtain a positive electrode material;

[0258] The sintering temperature is 700℃ and the time is 10h;

[0259] The molar ratio of sodium in sodium carbonate to sodium electrolytic precursor is 1.02:1.

[0260] Comparative Application Example 3

[0261] This comparative application example provides a method for preparing a positive electrode material, the preparation method comprising the following steps:

[0262] Sodium carbonate was mixed with the sodium electrode precursor obtained in Comparative Example 3, and the mixture was roasted in a tube furnace under oxygen flow to obtain a positive electrode material;

[0263] The sintering temperature is 700℃ and the time is 10h;

[0264] The molar ratio of sodium in sodium carbonate to sodium electrolytic precursor is 1.02:1.

[0265] Performance Characterization

[0266] The positive electrode materials provided in Application Examples 1-8 and Comparative Application Examples 1-3 were prepared into button batteries:

[0267] The positive electrode material, conductive carbon black (Super P), and binder polyvinylidene fluoride (PVDF) are thoroughly stirred and mixed in an appropriate amount of N-methylpyrrolidone (NMP) in a weight ratio of 90:5:5 to form a uniform positive electrode slurry; the positive electrode slurry is coated on the positive electrode current collector aluminum foil, and after drying, it is punched into a disc with a diameter of 14 mm as the positive electrode sheet; a metal sodium sheet is used as the negative electrode sheet; a Celgard2400 model separator is used as the separator; the electrolyte is 1 mol / L NaClO4 (the solvent is ethylene carbonate and diethyl carbonate in a volume ratio of 1:1); the positive electrode sheet, separator, and negative electrode sheet are stacked in order, the electrolyte is added and the battery is sealed to obtain a button battery.

[0268] At 25°C and 0.1MPa, the button battery was charged at a constant current rate of 0.1C to a voltage of 4.05V, allowed to stand for 5 minutes, and then discharged at a constant current rate of 0.1C to a voltage of 2.5V, allowed to stand for 5 minutes. The discharge capacity was recorded as the first-cycle discharge specific capacity. According to the above method, 100 cycles of charge and discharge tests were performed to detect the cycle capacity retention rate.

[0269] Table 1

[0270] In summary, the preparation method of the sodium electrode precursor provided in the present application obtains a precursor of the first target particle size by co-precipitation. The zirconium salt used can improve the thermal stability of the material, and the tungsten salt can stabilize the structure of the material under high pressure. The present application prevents the occurrence of irreversible phase change by using doped modified salts and anion solutions, thereby improving the structural stability and the electrochemical performance of the corresponding positive electrode material.

[0271] The above description is only a specific implementation method of the present application, but the protection scope of the present application is not limited thereto. Those skilled in the art should understand that any changes or replacements that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application fall within the protection scope and disclosure scope of the present application.

Claims

1. A method for preparing a sodium electrode precursor, comprising the following steps: Adding a mixed metal salt solution, a precipitant solution, a complexing agent solution and an anion solution in parallel to the base liquid, and performing a first coprecipitation reaction to a first target particle size; The metal salts in the mixed metal salt solution include nickel salts, ferrous salts, copper salts, manganese salts and doped modified salts; the doped modified salts include zirconium salts and / or tungsten salts.

2. The preparation method according to claim 1, in, The base liquid is a combination of water, a precipitant solution and a complexing agent solution; Optionally, the pH value of the base solution is 9-13; Optionally, the concentration of the complexing agent in the base solution is 0.1-2 mol / L.

3. The preparation method according to claim 1 or 2, in, In the mixed metal salt solution, the total concentration of nickel salt, ferrous salt, copper salt and manganese salt is 0.5-5 mol / L; Optionally, in the mixed metal salt solution, the concentration of the doped modified salt is 0.1-0.5 mol / L; Optionally, the nickel salt includes any one of nickel sulfate, nickel nitrate or nickel chloride, or a combination of at least two thereof; Optionally, the ferrous salt includes any one of ferrous sulfate, ferrous nitrate or ferrous chloride, or a combination of at least two thereof; Optionally, the copper salt includes any one or a combination of at least two of copper sulfate, copper nitrate or copper chloride; Optionally, the manganese salt includes any one or a combination of at least two of manganese sulfate, manganese nitrate or manganese chloride; Optionally, the zirconium salt includes any one or a combination of at least two of zirconium sulfate, zirconium nitrate or zirconium chloride; Optionally, the tungsten salt comprises sodium tungstate.

4. The preparation method according to any one of claims 1 to 3, in, The precipitant solution is a sodium hydroxide solution with a concentration of 2-15 mol / L; Optionally, the complexing agent solution is aqueous ammonia with a concentration of 4-12 mol / L; Optionally, the solute in the anion solution includes diammonium hydrogen phosphate and / or sodium silicate; Optionally, the concentration of diammonium hydrogen phosphate in the anion solution is 0.1-0.5 mol / L; Optionally, the concentration of sodium silicate in the anion solution is 0.1-0.5 mol / L.

5. The preparation method according to any one of claims 1 to 4, in, The flow rate of the mixed metal salt solution is 4-100 L / h; Optionally, the flow rate of the complexing agent solution is 0.5-10 L / h; Optionally, the flow rate of the anion solution is 0.1-5 L / h; Optionally, the pH value of the first coprecipitation reaction is 7-13; Optionally, the temperature of the first coprecipitation reaction is 40-80°C; Optionally, the first target particle size is a particle size D50 of 5-8 μm.

6. The preparation method according to any one of claims 1 to 5, in, The preparation method further comprises the step of: Continue to add the ferrous solution, phosphate solution, complexing agent solution and anion solution in parallel, perform a second coprecipitation reaction to a second target particle size, and obtain the sodium electrode precursor through solid-liquid separation, washing and drying; Optionally, the solute in the ferrous solution includes ferrous sulfate and / or ferrous chloride; Optionally, the solute in the phosphate solution includes diammonium hydrogen phosphate and / or ammonium dihydrogen phosphate; Optionally, the concentration of the ferrous sulfate solution is 0.1-0.5 mol / L; Optionally, the concentration of the diammonium hydrogen phosphate solution is 0.1-0.5 mol / L; Optionally, the flow rate of the ferrous sulfate solution is 4-100 L / h; Optionally, the flow rate of the diammonium hydrogen phosphate solution is 1-20 L / h; Optionally, the pH value of the second coprecipitation reaction is 7-13; Optionally, the temperature of the second coprecipitation reaction is 40-80°C; Optionally, the second target particle size is a particle size D50 reaching 10-15 μm.

7. A sodium electrode precursor prepared by the preparation method according to any one of claims 1 to 6.

8. A method for preparing a positive electrode material, comprising the following steps: A sodium source is mixed with the sodium electrode precursor according to claim 7, and sintered to obtain the positive electrode material.

9. A positive electrode material prepared by the preparation method according to claim 8.

10. An electrode comprising the sodium electrode precursor according to claim 7, or comprising the positive electrode material according to claim 9.

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