Copper-containing precursors and their preparation methods, sodium-ion battery cathode materials and sodium-ion batteries

Abstract

This application relates to the technical field of sodium-ion batteries, providing a copper-containing precursor and its preparation method, a sodium-ion battery cathode material, and a sodium-ion battery. The preparation method of the copper-containing precursor includes the following steps: preparing a copper salt solution and a salt solution containing nickel, iron, manganese, and M; the copper salt solution contains a chelating agent; dividing the nickel, iron, manganese, and M salt solution into a first salt solution and a second salt solution, and dividing the copper salt solution into a first copper salt solution and a second copper salt solution; mixing the first salt solution and the first copper salt solution with a precipitant and a complexing agent to perform a first precipitation reaction to obtain seed crystals; adding the second salt solution and the second copper salt solution to the seed crystals to perform a second precipitation reaction to obtain the copper-containing precursor. The copper element in the copper-containing precursor prepared by this application is uniformly distributed, and the sodium-ion battery cathode material exhibits high air stability and stable particle structure. When applied to sodium-ion batteries, it can effectively improve the energy density of sodium-ion batteries.

Description

Technical Field

[0001] This application belongs to the field of sodium-ion battery technology, and particularly relates to a copper-containing precursor and its preparation method, a sodium battery cathode material, and a sodium battery. Background Technology

[0002] Sodium-ion batteries are a type of rechargeable battery that primarily relies on the movement of sodium ions between the positive and negative electrodes to function, similar to the working principle of lithium-ion batteries. They were recognized as one of the top ten emerging technologies in the field of chemistry in 2022.

[0003] The cathode material of sodium-ion batteries is usually a layered sodium oxide, which readily reacts with moisture and carbon dioxide in the environment, resulting in a significant increase in residual sodium content on the particle surface and greatly weakening the electrochemical performance of sodium-ion batteries. Studies have found that copper doping is beneficial for enhancing the air stability of battery materials, but copper ions form copper hydroxide or copper carbonate precipitates that are readily soluble in ammonia systems and are very unstable during precipitation reactions, exhibiting severe segregation and making it difficult to form a uniform distribution with other elements. Summary of the Invention

[0004] The purpose of this application is to provide a copper-containing precursor and its preparation method, a sodium battery cathode material, and a sodium battery, aiming to solve the problems of uneven copper element distribution and unstable precipitation in existing copper-containing precursors.

[0005] To achieve the above-mentioned objectives, the technical solution adopted in this application is as follows:

[0006] In a first aspect, this application provides a method for preparing a copper-containing precursor, comprising the following steps:

[0007] Based on the general chemical formula of copper-containing precursors Ni a Cu b Mn c Fe d M β X, prepare copper salt solutions and salt solutions containing nickel, iron, manganese and M respectively; wherein M includes at least one of titanium, zirconium, antimony, zinc, tin, magnesium, calcium and aluminum, X is an anion, a+b+c+d+β=1, and the copper salt solutions contain chelating agents;

[0008] The salt solution containing nickel, iron, manganese and M is divided into a first salt solution and a second salt solution, and the copper salt solution is divided into a first copper salt solution and a second copper salt solution.

[0009] The first salt solution, the first copper salt, a precipitant, and a complexing agent are mixed to carry out a first precipitation reaction to obtain seed crystals.

[0010] The second salt solution and the second copper salt solution are added to the seed crystal to carry out a second precipitation reaction to obtain the copper-containing precursor.

[0011] The method for preparing copper-containing precursors provided in the first aspect of this application makes the precipitation of Cu more stable by adding a chelating agent in advance, and the Cu-containing precursors are synthesized in a controllable manner. This greatly avoids the formation of amorphous morphology and decrease in tap volume of particles due to the introduction of Cu. The preparation method is compatible with the existing production process of copper-containing precursors and can greatly reduce the use of high-cost complexing agents, making it easy to mass-produce on a large scale.

[0012] Secondly, this application provides a copper-containing precursor, which is prepared by the method provided in the first aspect.

[0013] The copper element in the copper-containing precursor provided in the second aspect of this application is uniformly distributed.

[0014] Thirdly, this application provides a sodium-ion battery cathode material, which is obtained by calcining a copper-containing precursor prepared by the preparation method provided in the first aspect with a sodium salt.

[0015] The sodium-ion battery cathode material provided in the third aspect of this application has the characteristics of large single crystal particles, uniform distribution of copper elements, stable structure, and a composite phase.

[0016] Fourthly, this application provides a sodium-ion battery, including the sodium-ion battery cathode material provided in the third aspect.

[0017] The sodium-ion battery provided in the fourth aspect of this application effectively improves the limiting compaction degree of the single-crystal cathode material when applied to sodium-ion batteries, thereby effectively increasing the upper limit voltage of the sodium-ion battery and thus effectively improving the energy density of the sodium-ion battery. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 FESEM image of the copper-containing precursor provided in Embodiment 1 of the present invention;

[0020] Figure 2 The FESEM image of the copper-containing precursor provided in Embodiment 2 of the present invention;

[0021] Figure 3 The image shown is a FESEM image of the composite phase single-crystal sodium-ion battery cathode material provided in Example 1 of this invention.

[0022] Figure 4The image shown is a FESEM image of the composite phase single-crystal sodium-ion battery cathode material provided in Example 2 of this invention.

[0023] Figure 5 The image shown is a FESEM image of the copper-containing precursor provided in Comparative Example 1 of this invention.

[0024] Figure 6 The image shown is a FESEM image of the copper-containing precursor provided in Comparative Example 2 of this invention.

[0025] Figure 7 The image shown is a FESEM image of the copper-containing precursor provided in Comparative Example 3 of this invention.

[0026] Figure 8 This is a FESEM image of the copper-containing precursor provided in Comparative Example 4 of the present invention. Detailed Implementation

[0027] To make the technical problems, technical solutions, and beneficial effects of this application clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0028] In this application, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0029] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0030] It should be understood that in the various embodiments of this application, the order of the above processes does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0031] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0032] The weights of the relevant components mentioned in the embodiments of this application can refer not only to the specific content of each component, but also to the proportional relationship between the weights of the components. Therefore, any scaling up or down of the content of the relevant components according to the embodiments of this application is within the scope disclosed in the embodiments of this application. Specifically, the mass described in the embodiments of this application can be a mass unit known in the chemical industry, such as μg, mg, g, or kg.

[0033] The terms "first" and "second" are used for descriptive purposes only, to distinguish objects, such as substances, from one another, and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. For example, without departing from the scope of the embodiments of this application, "first XX" may also be referred to as "second XX," and similarly, "second XX" may also be referred to as "first XX." Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0034] The first aspect of this application provides a method for preparing a copper-containing precursor, comprising the following steps:

[0035] S1 is based on the general chemical formula Ni of the copper-containing precursor. a Cu b Mn c Fe d M β X, prepare copper salt solutions and salt solutions containing nickel, iron, manganese and M respectively; wherein M includes at least one of titanium, zirconium, antimony, zinc, tin, magnesium, calcium and aluminum, X is an anion, and the copper salt solutions contain chelating agents;

[0036] S2 divides the salt solution containing nickel, iron, manganese and M into a first salt solution and a second salt solution, and divides the copper salt solution into a first copper salt solution and a second copper salt solution;

[0037] S3 mixes the first salt solution, the first copper salt solution, a precipitant, and a complexing agent to carry out the first precipitation reaction to obtain seed crystals;

[0038] S4. The second salt solution and the second copper salt solution are added to the seed crystal to carry out the second precipitation reaction to obtain the copper-containing precursor.

[0039] By adding a chelating agent in advance, the precipitation of copper becomes more stable, and a copper-containing precursor is synthesized in a controllable manner. This greatly avoids the formation of amorphous morphology and decreased tap volume caused by the introduction of copper. The preparation method is compatible with existing copper-containing precursor production processes and can significantly reduce the use of high-cost complexing agents, making it easy for large-scale mass production. The specific principle is that the binding strength between the chelating agent and copper ions is much higher than the dissolving power of ammonia. Adding the chelating agent in advance to the copper liquid greatly reduces the corrosion of copper by ammonia. By keeping the copper liquid inlet away from other metal liquids and the ammonia inlet, the stability of copper ion precipitation in the ammonia system is controlled, achieving simultaneous precipitation with elements such as nickel, iron, manganese, zinc, and aluminum, thus obtaining a precursor containing Cu.

[0040] The general chemical formula of the copper-containing precursor to be prepared in this application embodiment is Ni. a Cu b Mn c Fe d M β X; where M includes at least one of titanium, zirconium, antimony, zinc, tin, magnesium, calcium, and aluminum, and X is an anion, a+b+c+d+β=1.

[0041] In the application, X is (OH)2. 2- CO3 2- C2O4 2- Anionic groups that can form precipitates with the aforementioned metal ions. In a more specific embodiment, (OH)₂ is preferred. 2- .

[0042] In some embodiments, the ratio of the molar amount of chelating agent added to the molar content of copper ions in the copper salt solution is 0.02 to 1.5:1. Specifically, the ratio can be any value within the range of 0.02 to 1.5:1, such as 0.02:1, 0.1:1, 0.5:1, 0.6:1, 0.8:1, 1.0:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, etc. Preferably, the ratio of the molar amount of chelating agent added to the molar content of copper ions in the copper salt solution is 1 / 30 to 1:1. Specifically, the ratio of the molar amount of chelating agent added to the molar content of copper ions in the copper salt solution can be any value within the range of 1 / 30 to 1:1, such as 1 / 25, 1 / 20, 1 / 15, 1 / 10, 1 / 8, 1 / 5, 1 / 3, 1 / 2, etc. This is because different amounts of chelating agents can regulate the complexation strength of copper ions, optimize the precipitation rate of copper ions, and ultimately affect the sample parameters and morphological characteristics of copper-containing precursors.

[0043] In some embodiments, the chelating agent includes at least one of sodium citrate, disodium ethylenediaminetetraacetate, ethylenediaminetetraacetic acid, sodium diethylenetriaminepentacarboxylate, sodium aminotriacetate, citric acid, ammonium citrate, and tartaric acid.

[0044] In some embodiments, the complexing agent includes ammonia or a mixed solution of ammonia and an additive; the additive may include at least one of ammonium oxalate, thiourea, oxalic acid, sodium citrate, disodium ethylenediaminetetraacetate, tartaric acid, etc., and the molar ratio of ammonia to additive in the ammonia solution is 0.7 to 1:1. Under the complexing environment of ammonia within this concentration range, copper ion precipitation can be more stable, resulting in a copper-containing precursor with a uniform copper element distribution.

[0045] In some embodiments, the precipitant includes a first precipitant and a second precipitant, wherein the first precipitant includes at least one of sodium hydroxide solution and potassium hydroxide solution, and the second precipitant includes at least one of sodium carbonate solution, sodium bicarbonate solution, sodium oxalate solution, and oxalic acid solution. The above precipitant solutions can provide hydroxide ions, carbonate ions, or oxalate ions to ensure the stable precipitation of copper ions.

[0046] In some embodiments, the salts in the copper salt solution and the salt solutions containing nickel, iron, manganese, and M are at least one of sulfate, nitrate, acetate, and chlorate. Specifically, the copper salt in the copper salt solution can be at least one of soluble copper sulfate, copper nitrate, copper acetate, and copper chlorate, and the copper salt solution can be prepared by dissolving the above-mentioned copper salt in an aqueous solvent; the nickel salt in the salt solutions containing nickel, iron, manganese, and M can be at least one of soluble nickel sulfate, nickel nitrate, nickel acetate, and nickel chlorate; the iron salt can be at least one of soluble ferric sulfate, ferric nitrate, ferric acetate, and ferric chlorate; the manganese salt can be at least one of soluble manganese sulfate, manganese nitrate, manganese acetate, and manganese chlorate; and the salt corresponding to M can be at least one of soluble sulfate, nitrate, acetate, and chlorate corresponding to M, and the salt solutions containing nickel, iron, manganese, and M can be prepared by dissolving the above-mentioned nickel salt, iron salt, manganese salt, and the salt corresponding to M in an aqueous solvent.

[0047] In some embodiments, the ratio of the total molar feed rate of metal ions in the copper salt solution and the salt solution containing nickel, iron, manganese, or M to the molar feed rate of the first precipitant is 1:1.8 to 2.4. Specifically, the ratio of the total molar feed rate of metal ions in the copper salt solution and the salt solution containing nickel, iron, manganese, or M to the molar feed rate of the first precipitant can be any ratio within the range of 1:1.8 to 2.4, such as 1:1.8, 1:1.9, 1:2, 1:2.1, 1:2.2, 1:2.3, or 1:2.4.

[0048] In some embodiments, the ratio of the total molar feed rate of metal ions in the copper salt solution and the salt solution containing nickel, iron, manganese, or M to the molar feed rate of the second precipitant is 1:1.1 to 1:5. Specifically, the ratio of the total molar feed rate of metal ions in the copper salt solution and the salt solution containing nickel, iron, manganese, or M to the molar feed rate of the second precipitant can be any ratio within the range of 1:1.1 to 1.5, such as 1:1.1, 1:1.2, 1:1.3, 1:1.4, or 1:1.5.

[0049] In application, when the feed rate ratio of metal ions to the first precipitant is 1:1.8 to 2.4, and the feed rate ratio of metal ions to the second precipitant is 1:1.1 to 1.5, the precipitation of copper ions can be stably controlled, thereby generating a copper-containing precursor with uniform copper element distribution, ensuring the generation of a copper-containing precursor of single-crystal composite phase.

[0050] In some embodiments, the first precipitation reaction and the second precipitation reaction are carried out in a reaction vessel, which includes a vessel body and a vessel cover. The vessel cover is disposed on the vessel body, and a first feed inlet is opened at one end of the vessel body near the vessel cover, and a second feed inlet is opened at one end of the vessel body away from the vessel cover.

[0051] The first inlet is used to feed copper salt solution; the second inlet is used to feed salt solution containing nickel, iron, manganese, and M.

[0052] In an ammonia complexation environment, copper precipitation is stabilized by adding a chelating agent in advance, and copper salt solution is cleverly combined and enters the reactor through the first feed port. Salt solutions containing nickel, iron, manganese, and M enter the reactor through the second feed port, thus separating them in position. This allows for the controlled synthesis of copper-containing precursors, greatly avoiding the formation of amorphous morphology and decreased tapping due to the introduction of copper.

[0053] A second aspect of this application provides a copper-containing precursor, prepared by the preparation method provided in the first aspect, wherein the general chemical formula of the copper-containing precursor is Ni. a Cu b Mn c Fe d M β X and M include at least one of titanium, zirconium, antimony, zinc, tin, magnesium, calcium, and aluminum, where X is an anion and a+b+c+d+β=1.

[0054] Furthermore, the range of values ​​for a is 0 ≤ a < 1; the range of values ​​for b is 0 < b < 0.3; the range of values ​​for c is 0 ≤ c < 1; the range of values ​​for d is 0 ≤ d < 1; and the range of values ​​for β is 0 ≤ β < 1.

[0055] In some embodiments, the particle size of the copper-containing precursor is 3 μm to 20 μm, and the radius ratio of the seed particle to the copper-containing precursor particle is 0.1 to 0.6:1. The copper element in the copper-containing precursor prepared by the above method is uniformly distributed, and the single crystal particles are large.

[0056] The third aspect of this application provides a sodium-ion battery cathode material, which is obtained by calcining a copper-containing precursor prepared by the preparation method provided in the first aspect with a sodium salt.

[0057] By adding a copper-containing precursor with uniform copper distribution, and utilizing the homogeneous diffusion of copper ions in the precursor during subsequent calcination, a large single-crystal particle cathode material with uniform copper distribution of P2-O3 composite phase can be prepared. This can greatly reduce the use of high-cost complexing agents and facilitate large-scale mass production.

[0058] In some embodiments, the cathode material of the sodium-ion battery is a single-crystal large particle of P2-O3 composite phase, and the molar ratio of sodium ions in the sodium salt to metal ions in the copper-containing precursor is 0.8–0.9:1. Further, the molar ratio of sodium ions in the sodium salt to metal ions in the copper-containing precursor is 0.75–0.85:1. Specifically, the molar ratio of sodium ions in the sodium salt to metal ions in the copper-containing precursor can be 0.75:1, 0.76:1, 0.77:1, 0.78:1, 0.79:1, 0.80:1, 0.81:1, 0.82:1, 0.83:1, 0.84:1, or 0.85:1. Controlling the molar ratio of sodium ions in the sodium salt to metal ions in the copper-containing precursor within 0.75–0.85:1 ensures that the phase structure of the cathode material obtained after sintering is a composite phase. Deviations from this range will result in the composite phase structure not being obtained after sintering.

[0059] In some embodiments, the calcination process includes: heating to 930°C to 1100°C at a rate of 5°C / min to 10°C / min, calcining for 4h to 7h, and then cooling to 800°C to 910°C and calcining for 10h to 15h.

[0060] By controlling the high and low temperature sintering process, the copper uniformly distributed in the copper-containing precursor can be easily diffused during calcination, and large single crystal particles of a stable sodium-ion battery cathode material with uniform copper distribution in the P2-O3 composite phase can be controlled and prepared.

[0061] In some embodiments, the sodium salt includes at least one of sodium carbonate, sodium hydroxide, and sodium acetate.

[0062] The fourth aspect of this application provides a sodium-ion battery, including the sodium-ion battery cathode material provided in the third aspect.

[0063] When single-crystal cathode materials are applied to sodium-ion batteries, the ultimate compaction degree of the sodium-ion battery cathode material is effectively improved, which can effectively increase the upper limit voltage of the sodium-ion battery, and thus effectively improve the energy density of the sodium-ion battery.

[0064] The following description is based on specific embodiments.

[0065] Example 1

[0066] This invention provides a copper-containing precursor and its preparation method, as well as a sodium-ion battery cathode material.

[0067] A method for preparing a copper-containing precursor includes the following steps:

[0068] S1 is based on the chemical formula Ni of the copper-containing precursor. 0.27 Cu 0.03 Fe 0.3 Mn 0.4 (OH)₂, where a = 0.27, b = 0.03, c = 0.4, d = 0.3, and β = 0. Nickel sulfate, ferrous sulfate, and manganese nitrate were dissolved in water at a molar ratio of 0.27:0.3:0.4 to prepare a nickel-iron-manganese solution with a total concentration of 2.5 mol / L. Copper sulfate and disodium ethylenediaminetetraacetate were dissolved in water at a molar ratio of 1:0.05 to prepare a copper salt solution with a concentration of 0.4 mol / L. Sodium hydroxide was dissolved in water to prepare a sodium hydroxide solution with a concentration of 5 mol / L as a precipitant, and ammonia gas was dissolved in water to prepare an ammonia solution with a concentration of 5 mol / L as a complexing agent.

[0069] S2 divides the nickel-iron-manganese liquid into a first salt solution and a second salt solution, and the copper salt solution into a first copper salt solution and a second copper salt solution;

[0070] S3 controls the temperature inside the reactor (including the reactor body and the reactor lid, with the lid on the reactor body; a first feed inlet is located at the end of the reactor body near the lid, and a second feed inlet is located at the end of the reactor body away from the lid) at 70°C. Nitrogen gas is continuously introduced into the sedimentation reactor while stirring is maintained. The first salt solution, precipitant, complexing agent, and first copper salt solution are fed in a parallel flow, with the first copper salt solution fed through the first feed inlet, and the first salt solution, precipitant, and complexing agent fed through the second feed inlet. The total gold content of the first salt solution and the first copper salt is controlled. The ratio of the total molar feed rate of the metal ions to the molar feed rate of sodium hydroxide in the precipitant is 1:2.2. Specifically, the feed rate of the first salt solution is 10 L / min, the feed rate of the first copper salt is 0.773 L / min, and the feed rate of sodium hydroxide is 1.324 L / min. The ammonia concentration in the system of the reactor is controlled at 0.18 mol / L. After the reaction continues for 4 hours, the feed rate of sodium hydroxide is reduced (to 1.192 L / min), and the reaction continues for 2 hours to obtain seed crystals.

[0071] After obtaining seed crystals in S4, the feed continued, with the second salt solution fed at a rate of 20 L / min, the second copper salt at 1.446 L / min, and the sodium hydroxide at 2.3 L / min, while maintaining the ammonia concentration in the reactor at 0.14 mol / L. The precipitation reaction was maintained for 87 hours, at which point the particle size reached 6 μm, at which point the feed was stopped and the stirring was turned off, yielding Ni. 0.27 Cu 0.03 Fe 0.3 Mn 0.4 (OH)2 precursor.

[0072] The above Ni 0.27 Cu 0.03 Fe 0.3 Mn 0.4 (OH)₂ precursor powder and sodium carbonate were weighed and mixed at a mass ratio of 1.5:0.86, ground, and then calcined in an air atmosphere: specifically, the temperature was increased from room temperature to 980℃ at a rate of 3℃ / min and held for 4 hours, then the temperature was reduced to 885℃ and held for 15 hours, and finally cooled to room temperature with the furnace to obtain the P₂-O₃ composite phase Na. 0.82 Ni 0.27 Cu 0.03 Fe 0.3 Mn 0.4 (OH)2 cathode material.

[0073] Example 2

[0074] This invention provides a copper-containing precursor and its preparation method, as well as a sodium-ion battery cathode material.

[0075] A method for preparing a copper-containing precursor includes the following steps:

[0076] S1 is based on the chemical formula Ni of the copper-containing precursor. 0.2 Cu 0.2 Fe 0.3 Mn 0.3 (OH)₂, where a = 0.2, b = 0.2, c = 0.3, d = 0.3, and β = 0. Nickel sulfate, ferrous sulfate, copper sulfate, and manganese nitrate were dissolved in water at a molar ratio of 0.2:0.3:0.3 to prepare a nickel-iron-manganese solution with a total concentration of 2.5 mol / L. Copper sulfate and sodium tartrate were dissolved in water at a molar ratio of 1:1 / 15 to prepare a copper salt solution with a copper concentration of 0.6 mol / L. Sodium hydroxide was dissolved in water to prepare a sodium hydroxide solution with a concentration of 5 mol / L as a precipitant, and ammonia gas was dissolved in water to prepare an ammonia solution with a concentration of 5 mol / L as a complexing agent.

[0077] S2 divides the nickel-iron-manganese liquid into a first salt solution and a second salt solution, and the copper salt solution into a first copper salt solution and a second copper salt solution;

[0078] S3 controls the temperature inside the reactor (including the reactor body and the reactor lid, with the lid on the reactor body, a first feed port at the end of the reactor body near the lid, and a second feed port at the end of the reactor body away from the lid) at 70°C. Nitrogen gas is continuously introduced into the sedimentation vessel while stirring is maintained. The first salt solution, precipitant, complexing agent, and first copper salt solution are fed in a parallel flow, with the first copper salt solution fed through the first feed port, and the first salt solution, precipitant, and complexing agent fed through the second feed port. The temperature of the first salt solution and the second copper salt solution is controlled. The ratio of the total molar feed rate of the copper salt to the molar feed rate of sodium hydroxide in the precipitant is 1:2.1. Specifically, the feed rate of the first salt solution is 6 L / min, the feed rate of the first copper salt is 5 L / min, and the feed rate of sodium hydroxide is 1.43 L / min. The ammonia concentration in the reactor system is controlled at 0.1 mol / L. After the reaction continues for 4 hours, the feed rate of sodium hydroxide is reduced (to 1.3 L / min), and the reaction continues for another 2 hours to obtain seed crystals.

[0079] After obtaining seed crystals in S4, the feed continues, with the second salt solution fed at a rate of 12 L / min, the second copper salt at 10 L / min, and the sodium hydroxide at 2.67 L / min. The ammonia concentration in the reactor is maintained at 0.15 mol / L, and the precipitation reaction is maintained for 83 hours. Once the particle size reaches 6 μm, the feed is stopped, and the stirring is turned off, yielding Ni. 0.2 Cu 0.2 Fe 0.3 Mn 0.3 (OH)2 precursor.

[0080] The above Ni 0.2 Cu 0.2 Fe 0.3 Mn 0.3 (OH)₂ precursor powder and sodium carbonate were weighed and mixed at a mass ratio of 1.5:0.86, ground, and then calcined in an air or oxygen atmosphere at a rate of 3°C / min from room temperature. -1 The temperature was rapidly increased to 950℃ and held for 5 hours, then decreased to 865℃ and held for 15 hours. Finally, the furnace was cooled to room temperature to obtain the P2-O3 composite phase Na. 0.82 Ni 0.2 Cu 0.2 Fe 0.3 Mn 0.3 (OH)2 cathode material.

[0081] Example 3

[0082] This invention provides a copper-containing precursor and its preparation method, as well as a sodium-ion battery cathode material.

[0083] A method for preparing a copper-containing precursor includes the following steps:

[0084] S1 is based on the chemical formula Ni of the copper-containing precursor. 0.1 Cu 0.1 Fe 0.3 Mn 0.5 (OH)₂, where a = 0.1, b = 0.1, c = 0.5, d = 0.3, and β = 0. Nickel sulfate, ferrous sulfate, and manganese nitrate were dissolved in water at a molar ratio of 0.1:0.1:0.5 to prepare a nickel-iron-manganese solution with a total concentration of 2.5 mol / L. Copper sulfate and citric acid were dissolved in water at a molar ratio of 1:0.1 to prepare a copper salt solution with a copper concentration of 0.6 mol / L. Sodium hydroxide was dissolved in water to prepare a sodium hydroxide solution with a concentration of 5 mol / L as a precipitant, and ammonia gas was dissolved in water to prepare an ammonia solution with a concentration of 5 mol / L as a complexing agent.

[0085] S2 divides the nickel-iron-manganese liquid into a first salt solution and a second salt solution, and the copper salt solution into a first copper salt solution and a second copper salt solution;

[0086] S3 controls the temperature inside the reactor (including the reactor body and the reactor lid, with the lid on the reactor body, a first feed inlet at the end of the reactor body near the lid, and a second feed inlet at the end of the reactor body away from the lid) at 45°C. Nitrogen gas is continuously introduced into the sedimentation reactor while stirring is maintained. The first salt solution, precipitant, complexing agent, and first copper salt solution are fed in a parallel flow, with the first copper salt solution fed through the first feed inlet, and the first salt solution, precipitant, and complexing agent fed through the second feed inlet. The total gold content of the first salt solution and the first copper salt is controlled. The ratio of the total molar feed rate of the metal ions to the molar feed rate of sodium hydroxide in the precipitant is 1:2.26. Specifically, the feed rate of the first salt solution is 10 L / min, the feed rate of the first copper salt is 3.7 L / min, and the feed rate of sodium hydroxide is 1.966 L / min. The ammonia concentration in the system of the reactor is controlled at 0.1 mol / L. After the reaction continues for 2.5 h, the feed rate of sodium hydroxide is reduced (to 1.93 L / min), and the reaction continues for another 3.5 h to obtain seed crystals.

[0087] After obtaining seed crystals in S4, the feed continues, with the second salt solution fed at a rate of 20 L / min, the second copper salt at 7.4 L / min, and the sodium hydroxide at 3.72 L / min. The ammonia concentration in the reactor is maintained at 0.1 mol / L, and the precipitation reaction is continued for 101 h. At this point, when the particle size reaches 10 μm, the feed is stopped, and the stirring is turned off, thus obtaining Ni. 0.1 Cu 0.1Fe 0.3 Mn 0.5 (OH)2 precursor.

[0088] The above Ni 0.2 Cu 0.2 Fe 0.3 Mn 0.3 (OH)₂ precursor powder and sodium carbonate were weighed and mixed at a mass ratio of 1.5:0.88, ground, and then calcined in an air or oxygen atmosphere at a rate of 3°C / min from room temperature. -1 The temperature was rapidly increased to 950℃ and held for 5 hours, then decreased to 865℃ and held for 15 hours. Finally, the furnace was cooled to room temperature to obtain the P2-O3 composite phase Na. 0.82 Ni 0.1 Cu 0.1 Fe 0.3 Mn 0.5 (OH)2 cathode material.

[0089] Example 4

[0090] This invention provides a copper-containing precursor and its preparation method, as well as a sodium-ion battery cathode material.

[0091] A method for preparing a copper-containing precursor includes the following steps:

[0092] S1 is based on the chemical formula Ni of the copper-containing precursor. 0.4 Cu 0.1 Fe 0.2 Mn 0.3 (OH)₂, where a = 0.4, b = 0.1, c = 0.3, d = 0.2, and β = 0. Nickel sulfate, ferrous sulfate, and manganese nitrate were dissolved in water at a molar ratio of 0.4:0.2:0.3 to prepare a nickel-iron-manganese solution with a total concentration of 2.5 mol / L. Copper acetate and citric acid were dissolved in water at a molar ratio of 1:1 / 9 to prepare a copper salt solution with a copper concentration of 1 mol / L. Sodium hydroxide was dissolved in water to prepare a sodium hydroxide solution with a concentration of 5 mol / L as a precipitant, and ammonia gas was dissolved in water to prepare an ammonia solution with a concentration of 5 mol / L as a complexing agent.

[0093] S2 divides the nickel-iron-manganese liquid into a first salt solution and a second salt solution, and the copper salt solution into a first copper salt solution and a second copper salt solution;

[0094] S3 controls the temperature inside the reactor (including the reactor body and the reactor lid, with the lid on the reactor body; a first feed inlet is located at the end of the reactor body near the lid, and a second feed inlet is located at the end of the reactor body away from the lid) at 50°C. Nitrogen gas is continuously introduced into the sedimentation reactor while stirring is maintained. The first salt solution, precipitant, complexing agent, and first copper salt solution are fed in a parallel flow, with the first copper salt solution fed through the first feed inlet, and the first salt solution, precipitant, and complexing agent fed through the second feed inlet. The temperature of the first salt solution and the first copper salt solution is controlled. The ratio of the total molar feed rate of total metal ions to the molar feed rate of sodium hydroxide in the precipitant was 1:2.26. Specifically, the feed rate of the first salt solution was 10 L / min, the feed rate of the first copper salt was 2.78 L / min, and the feed rate of sodium hydroxide was 2.65 L / min. The ammonia concentration in the system of the reactor was controlled at 0.1 mol / L. After the reaction continued for 5 hours, the feed rate of sodium hydroxide was reduced (to 2.55 L / min), and the reaction continued for another hour to obtain seed crystals.

[0095] After obtaining seed crystals in S4, the feed continues, with the second salt solution fed at a rate of 20 L / min, the second copper salt at 5.56 L / min, and the sodium hydroxide at 4.95 L / min. The ammonia concentration in the reactor is maintained at 0.2 mol / L, and the precipitation reaction is maintained for 101 h. At this point, when the particle size reaches 10 μm, the feed is stopped, and the stirring is turned off, thus obtaining Ni. 0.4 Cu 0.1 Fe 0.2 Mn 0.3 (OH)2 precursor.

[0096] The above Ni 0.4 Cu 0.1 Fe 0.2 Mn 0.3 (OH)₂ precursor powder and sodium carbonate were weighed and mixed at a mass ratio of 1.5:0.85, ground, and then calcined in an air or oxygen atmosphere at a rate of 3°C / min from room temperature. -1 The temperature was rapidly increased to 950℃ and held for 7 hours, then decreased to 855℃ and held for 15 hours. Finally, the furnace was cooled to room temperature to obtain the P2-O3 composite phase Na. 0.82 Ni 0.4 Cu 0.1 Fe 0.2 Mn 0.3 (OH)2 cathode material.

[0097] Example 5

[0098] This invention provides a copper-containing precursor and its preparation method, as well as a sodium-ion battery cathode material.

[0099] A method for preparing a copper-containing precursor includes the following steps:

[0100] S1 is based on the chemical formula Ni of the copper-containing precursor. 0.3 Cu 0.1 Mg 0.05 Mn 0.55 (OH)₂, in the general chemical formula, a = 0.3, b = 0.1, c = 0.55, d = 0, β = 0.05. Nickel sulfate, magnesium acetate, and manganese sulfate are dissolved in water at a molar ratio of 0.3:0.05:0.55 to prepare a nickel-manganese solution with a total concentration of 2.0 mol / L. Copper nitrate and sodium citrate are dissolved in water at a molar ratio of 1:1 / 8 to prepare a copper salt solution with a concentration of 0.6 mol / L. Sodium hydroxide is dissolved in water to prepare a sodium hydroxide solution with a concentration of 5 mol / L as a precipitant, and ammonia gas is dissolved in water to prepare an ammonia solution with a concentration of 5 mol / L as a complexing agent.

[0101] S2 divides the nickel-manganese solution into a first salt solution and a second salt solution, and the copper salt solution into a first copper salt solution and a second copper salt solution;

[0102] S3 controls the temperature inside the reactor (including the reactor body and the reactor lid, with the lid on the reactor body; a first feed inlet is located at the end of the reactor body near the lid, and a second feed inlet is located at the end of the reactor body away from the lid) at 50°C. Nitrogen gas is continuously introduced into the sedimentation reactor while stirring is maintained. The first salt solution, precipitant, complexing agent, and first copper salt solution are fed in a parallel flow, with the first copper salt solution fed through the first feed inlet, and the first salt solution, precipitant, and complexing agent fed through the second feed inlet. The temperature of the first salt solution and the first copper salt solution is controlled. The ratio of the total molar feed rate of the total metal ions to the molar feed rate of sodium hydroxide in the precipitant was 1:2.26. Specifically, the feed rate of the first salt solution was 10 L / min, the feed rate of the first copper salt was 6.7 L / min, and the feed rate of sodium hydroxide was 2.13 L / min. The ammonia concentration in the system of the reactor was controlled at 0.4 mol / L. After the reaction continued for 6 hours, the feed rate of sodium hydroxide was reduced (to 2.03 L / min), and the reaction continued for another hour to obtain seed crystals.

[0103] After obtaining seed crystals in S4, the feed continues, with the second salt solution fed at a rate of 20 L / min, the second copper salt at 13.4 L / min, and the sodium hydroxide at 4 L / min. The ammonia concentration in the reactor is maintained at 0.4 mol / L, and the precipitation reaction is maintained for 56 hours. At this point, when the particle size reaches 3.5 μm, the feed is stopped, and the stirring is turned off, yielding Ni. 0.3 Cu 0.1 Mg 0.05 Mn 0.55 (OH)2 precursor.

[0104] The above Ni 0.3 Cu0.1 Mg 0.05 Mn 0.55 (OH)₂ precursor powder and sodium carbonate were weighed and mixed at a mass ratio of 1.5:0.86, ground, and then calcined in an air or oxygen atmosphere at a rate of 3°C / min from room temperature. -1 The temperature was rapidly increased to 960℃ and held for 6 hours, then decreased to 855℃ and held for 15 hours. Finally, the furnace was cooled to room temperature to obtain the P2-O3 composite phase Na. 0.82 Ni 0.3 Cu 0.1 Mg 0.05 Mn 0.55 (OH)2 cathode material.

[0105] Example 6

[0106] This invention provides a copper-containing precursor and its preparation method, as well as a sodium-ion battery cathode material.

[0107] A method for preparing a copper-containing precursor includes the following steps:

[0108] S1 is based on the chemical formula Cu of the copper-containing precursor. 0.2 Mn 0.8 (OH)₂, where a = 0, b = 0.2, c = 0.8, d = 0, and β = 0 in the general chemical formula. Manganese sulfate is dissolved in water to prepare a 2.5 mol / L manganese solution; copper sulfate and salicylic acid are dissolved in water at a molar ratio of 1:1 / 5 to prepare a 0.7 mol / L copper salt solution; sodium hydroxide is dissolved in water to prepare a 5 mol / L sodium hydroxide solution as a precipitant; and ammonia gas is dissolved in water to prepare a 5 mol / L ammonia solution as a complexing agent.

[0109] S2 divides the manganese solution into a first salt solution and a second salt solution, and the copper salt solution into a first copper salt solution and a second copper salt solution;

[0110] S3 controls the temperature inside the reactor (including the reactor body and the reactor lid, with the lid on the reactor body; a first feed inlet is located at the end of the reactor body near the lid, and a second feed inlet is located at the end of the reactor body away from the lid) at 60°C. Nitrogen gas is continuously introduced into the sedimentation reactor while stirring is maintained. The first salt solution, precipitant, complexing agent, and first copper salt solution are fed in a parallel flow, with the first copper salt solution fed through the first feed inlet, and the first salt solution, precipitant, and complexing agent fed through the second feed inlet. The temperature of the first salt solution and the first copper salt solution is controlled. The ratio of the total molar feed rate of the total metal ions to the molar feed rate of sodium hydroxide in the precipitant is 1:2.3. Specifically, the feed rate of the first salt solution is 10 L / min, the feed rate of the first copper salt is 8.9 L / min, and the feed rate of sodium hydroxide is 2.64 L / min. The ammonia concentration in the system of the reactor is controlled at 0.24 mol / L. After the reaction continues for 1 hour, the feed rate of sodium hydroxide is reduced (to 2.5 L / min) and the reaction continues for another hour to obtain seed crystals.

[0111] After obtaining seed crystals in S4, the feed continues, with the second salt solution fed at a rate of 20 L / min, the second copper salt at 17.8 L / min, and sodium hydroxide at 4.4 L / min. The ammonia concentration in the reactor is maintained at 0.24 mol / L, and the precipitation reaction is maintained for 61 hours. At this point, when the particle size reaches 7 μm, the feed is stopped, and the stirring is turned off, yielding Cu. 0.2 Mn 0.8 (OH)2 precursor.

[0112] The above Cu 0.2 Mn 0.8 (OH)₂ precursor powder and sodium carbonate were weighed and mixed at a mass ratio of 1.5:0.91, ground, and then calcined in an air or oxygen atmosphere at a rate of 3°C / min from room temperature. -1 The temperature was rapidly increased to 950℃ and held for 5 hours, then decreased to 845℃ and held for 15 hours. Finally, the furnace was cooled to room temperature to obtain the P2-O3 composite phase Na. 0.82 Cu 0.2 Mn 0.8 (OH)2 cathode material.

[0113] Example 7

[0114] This invention provides a copper-containing precursor and its preparation method, as well as a sodium-ion battery cathode material.

[0115] A method for preparing a copper-containing precursor includes the following steps:

[0116] S1 is based on the chemical formula Ni of the copper-containing precursor. 0.25 Cu 0.15 Fe 0.3 Mn 0.3(OH)₂, i.e., in the general chemical formula, a = 0.25, b = 0.15, c = 0.3, d = 0.3, β = 0. Nickel chlorate, ferrous nitrate, and manganese acetate were dissolved in water at a molar ratio of 0.25:0.3:0.3 to prepare a nickel-iron-manganese solution with a total concentration of 2 mol / L. Copper sulfate and ammonium tartrate were dissolved in water at a molar ratio of 1:1 / 10 to prepare a copper salt solution with a concentration of 0.7 mol / L. Sodium hydroxide was dissolved in water to prepare a sodium hydroxide solution with a concentration of 5 mol / L as a precipitant, and ammonia gas was dissolved in water to prepare an ammonia solution with a concentration of 5 mol / L as a complexing agent.

[0117] S2 divides the nickel-iron-manganese liquid into a first salt solution and a second salt solution, and the copper salt solution into a first copper salt solution and a second copper salt solution;

[0118] S3 controls the temperature inside the reactor (including the reactor body and the reactor lid, with the lid on the reactor body; a first feed inlet is located at the end of the reactor body near the lid, and a second feed inlet is located at the end of the reactor body away from the lid) at 70°C. Nitrogen gas is continuously introduced into the sedimentation reactor while stirring is maintained. The first salt solution, precipitant, complexing agent, and first copper salt solution are fed in a parallel flow, with the first copper salt solution fed through the first feed inlet, and the first salt solution, precipitant, and complexing agent fed through the second feed inlet. The temperature of the first salt solution and the first copper salt solution is controlled. The ratio of the total molar feed rate of the total metal ions to the molar feed rate of sodium hydroxide in the precipitant is 1:2.1. Specifically, the feed rate of the first salt solution is 10 L / min, the feed rate of the first copper salt is 5.35 L / min, and the feed rate of sodium hydroxide is 2.26 L / min. The ammonia concentration in the system of the reactor is controlled at 0.3 mol / L. After the reaction continues for 1 hour, the feed rate of sodium hydroxide is reduced (to 2.1 L / min). Seed crystals are obtained after 5 hours of reaction.

[0119] After obtaining seed crystals in S4, the feed continued, with the second salt solution fed at a rate of 20 L / min, the second copper salt at 10.7 L / min, and the sodium hydroxide at 3.98 L / min. The ammonia concentration in the reactor was maintained at 0.3 mol / L, and the precipitation reaction was continued for 113 h. At this point, when the particle size reached 13 μm, the feed was stopped, and the stirring was turned off, thus obtaining Ni. 0.25 Cu 0.15 Fe 0.3 Mn 0.3 (OH)2 precursor.

[0120] The above Ni 0.25 Cu 0.15 Fe 0.3 Mn 0.3(OH)₂ precursor powder and sodium carbonate were weighed and mixed at a mass ratio of 1.5:0.89, ground, and then calcined in an air or oxygen atmosphere at a rate of 3°C / min from room temperature. -1 The temperature was rapidly increased to 960℃ and held for 6 hours, then decreased to 845℃ and held for 15 hours. Finally, the furnace was cooled to room temperature to obtain the P2-O3 composite phase Na. 0.82 Ni 0.25 Cu 0.15 Fe 0.3 Mn 0.3 (OH)2 cathode material.

[0121] Example 8

[0122] This invention provides a copper-containing precursor and its preparation method, as well as a sodium-ion battery cathode material.

[0123] A method for preparing a copper-containing precursor includes the following steps:

[0124] S1 is based on the chemical formula Ni of the copper-containing precursor. 0.2 Cu 0.1 Zn 0.1 Mn 0.6 (OH)₂, i.e., in the general chemical formula, a = 0.2, b = 0.1, c = 0.6, d = 0, β = 0.1. Nickel chlorate, manganese acetate, and zinc sulfate were dissolved in water at a molar ratio of 0.2:0.6:0.1 to prepare a nickel-manganese-zinc solution with a total concentration of 1.5 mol / L. Copper sulfate and sodium diethylenetriaminepentacarboxylate were dissolved in water at a molar ratio of 1:1 / 10 to prepare a copper salt solution with a concentration of 0.5 mol / L. Sodium hydroxide was dissolved in water to prepare a sodium hydroxide solution with a concentration of 5 mol / L as a precipitant, and ammonia gas was dissolved in water to prepare an ammonia solution with a concentration of 5 mol / L as a complexing agent.

[0125] S2 divides the nickel-iron-manganese-zinc solution into a first salt solution and a second salt solution, and the copper salt solution into a first copper salt solution and a second copper salt solution;

[0126] S3 controls the temperature inside the reactor (including the reactor body and the reactor lid, with the lid on the reactor body; a first feed inlet is located at the end of the reactor body near the lid, and a second feed inlet is located at the end of the reactor body away from the lid) at 70°C. Nitrogen gas is continuously introduced into the sedimentation reactor while stirring is maintained. The first salt solution, precipitant, complexing agent, and first copper salt solution are fed in a parallel flow, with the first copper salt solution fed through the first feed inlet, and the first salt solution, precipitant, and complexing agent fed through the second feed inlet. The temperature of the first salt solution and the first copper salt solution is controlled. The ratio of the total molar feed rate of the total metal ions to the molar feed rate of sodium hydroxide in the precipitant is 1:2.1. Specifically, the feed rate of the first salt solution is 10 L / min, the feed rate of the first copper salt is 3.3 L / min, and the feed rate of sodium hydroxide is 1.59 L / min. The ammonia concentration in the system of the reactor is controlled at 0.3 mol / L. After the reaction continues for 1 hour, the feed rate of sodium hydroxide is reduced (to 1.36 L / min). Seed crystals are obtained after 5 hours of reaction.

[0127] After obtaining seed crystals in S4, the feed continues, with the second salt solution fed at a rate of 20 L / min, the second copper salt at 6.6 L / min, and the sodium hydroxide at 2.6 L / min. The ammonia concentration in the reactor is maintained at 0.3 mol / L, and the precipitation reaction is continued for 113 hours. At this point, when the particle size reaches 10 μm, the feed is stopped, and the stirring is turned off, thus obtaining Ni. 0.2 Cu 0.1 Zn 0.1 Mn 0.6 (OH)2 precursor.

[0128] The above Ni 0.2 Cu 0.1 Zn 0.1 Mn 0.6 (OH)₂ precursor powder and sodium carbonate were weighed and mixed at a mass ratio of 1.5:0.84, ground, and then calcined in an air or oxygen atmosphere at a rate of 3°C / min from room temperature. -1 The temperature was rapidly increased to 970℃ and held for 5 hours, then decreased to 885℃ and held for 15 hours. Finally, the furnace was cooled to room temperature to obtain the P2-O3 composite phase Na. 0.82 Ni 0.2 Cu 0.1 Zn 0.1 Mn 0.6 (OH)2 cathode material.

[0129] Example 9

[0130] This invention provides a copper-containing precursor and its preparation method, as well as a sodium-ion battery cathode material.

[0131] A method for preparing a copper-containing precursor includes the following steps:

[0132] S1 is based on the chemical formula Ni of the copper-containing precursor. 0.2 Cu 0.05 Zn 0.05 Fe 0.3 Mn 0.4 (OH)₂, i.e., in the general chemical formula, a = 0.2, b = 0.05, c = 0.4, d = 0.3, β = 0.05. Nickel chlorate, ferrous nitrate, manganese acetate, and zinc acetate were dissolved in water in a molar ratio of 0.2:0.3:0.4:0.05 to prepare a nickel-zinc-iron-manganese solution with a total concentration of 1.5 mol / L. Copper sulfate and sodium diethylenetriaminepentacarboxylate were dissolved in water in a molar ratio of 1:1 / 10 to prepare a copper salt solution with a concentration of 1.2 mol / L. Sodium hydroxide was dissolved in water to prepare a sodium hydroxide solution with a concentration of 10 mol / L as a precipitant, and ammonia gas was dissolved in water to prepare an ammonia solution with a concentration of 5 mol / L as a complexing agent.

[0133] S2 divides the nickel-zinc-iron-manganese solution into a first salt solution and a second salt solution, and the copper salt solution into a first copper salt solution and a second copper salt solution.

[0134] S3 controls the temperature inside the reactor (including the reactor body and the reactor lid, with the lid on the reactor body, a first feed inlet at the end of the reactor body near the lid, and a second feed inlet at the end of the reactor body away from the lid) at 57°C. Nitrogen gas is continuously introduced into the reactor while stirring is maintained. The first salt solution, precipitant, complexing agent, and first copper salt solution are fed in a parallel flow, with the first copper salt solution fed through the first feed inlet, and the first salt solution, precipitant, and complexing agent fed through the second feed inlet. The temperature of the first salt solution and the first copper salt solution is controlled. The ratio of the total molar feed rate of total metal ions to the molar feed rate of sodium hydroxide in the precipitant is 1:2.35. Specifically, the feed rate of the first salt solution is 10 L / min, the feed rate of the first copper salt is 0.65 L / min, and the feed rate of sodium hydroxide is 1.29 L / min. The ammonia concentration in the system of the reactor is controlled at 0.4 mol / L. After the reaction continues for 4 hours, the feed rate of sodium hydroxide is reduced (to 1.19 L / min). Seed crystals are obtained after 5 hours of reaction.

[0135] After obtaining seed crystals in S4, the feed continues, with the second salt solution fed at a rate of 20 L / min, the second copper salt at a rate of 1.3 L / min, and sodium hydroxide at a rate of 2 L / min. The precipitation reaction is maintained for 92 hours, at which point the particle size reaches 7 μm. Feeding is then stopped, and stirring is turned off, yielding Ni. 0.2 Cu 0.05 Zn 0.05 Fe 0.3 Mn 0.4 (OH)2 precursor.

[0136] The above Ni 0.2 Cu 0.05 Zn 0.05 Fe 0.3 Mn 0.4 (OH)₂ precursor powder and sodium carbonate were weighed and mixed at a mass ratio of 1.5:0.81, ground, and then calcined in an air or oxygen atmosphere at a rate of 3°C / min from room temperature. -1 The temperature was rapidly increased to 980℃ and held for 5 hours, then decreased to 845℃ and held for 15 hours. Finally, the furnace was cooled to room temperature to obtain the P2-O3 composite phase Na. 0.82 Ni 0. 2Cu 0.05 Zn 0.05 Fe 0.3 Mn 0.4 (OH)2 cathode material.

[0137] Example 10

[0138] This invention provides a copper-containing precursor and its preparation method, as well as a sodium-ion battery cathode material.

[0139] A method for preparing a copper-containing precursor includes the following steps:

[0140] S1 is based on the chemical formula Ni of the copper-containing precursor. 0.1 Cu 0.2 Fe 0.3 Mn 0.4 CO3, where a = 0.1, b = 0.2, c = 0.4, d = 0.3, and β = 0 in the general chemical formula. Nickel chlorate, ferrous nitrate, and manganese acetate were dissolved in water at a molar ratio of 0.1:0.3:0.4 to prepare a nickel-iron-manganese solution with a total concentration of 1.0 mol / L. Copper sulfate and ethylenediaminetetradic acid were dissolved in water at a molar ratio of 1:1 / 10 to prepare a copper salt solution with a concentration of 0.5 mol / L. Sodium carbonate was dissolved in water to prepare a 3 mol / L sodium carbonate solution as a precipitant, and ammonia gas was dissolved in water to prepare an ammonia solution with a concentration of 5 mol / L as a complexing agent.

[0141] S2 divides the nickel-iron-manganese liquid into a first salt solution and a second salt solution, and the copper salt solution into a first copper salt solution and a second copper salt solution;

[0142] S3 comprises a reactor body and a lid, with the lid mounted on the reactor body. A first feed inlet is located at the end of the reactor body near the lid, and a second feed inlet is located at the end of the reactor body furthest from the lid. The internal temperature is controlled at 45°C. Nitrogen gas is continuously introduced into the reactor while stirring is maintained. The first salt solution, precipitant, complexing agent, and first copper salt solution are fed in a parallel flow, with the first copper salt solution fed through the first feed inlet, and the first salt solution, precipitant, and complexing agent fed through the second feed inlet. The flow rate of the first salt solution and the first copper salt solution is controlled. The ratio of the total molar feed rate of the total metal ions to the molar feed rate of sodium hydroxide in the precipitant is 1:1.4. Specifically, the feed rate of the first salt solution is 10 L / min, the feed rate of the first copper salt is 6.38 L / min, and the feed rate of sodium hydroxide is 3.14 L / min. The ammonia concentration in the system of the reactor is controlled at 0.1 mol / L. After the reaction continues for 2 hours, the feed rate of sodium hydroxide is increased (to 3.4 L / min). Seed crystals are obtained after 4 hours of reaction.

[0143] After obtaining seed crystals in S4, the feed continues, with the second salt solution fed at a rate of 20 L / min, the second copper salt at 12.76 L / min, and the sodium hydroxide at 6.6 L / min. The ammonia concentration in the reactor is maintained at 0.1 mol / L, and the precipitation reaction is continued for 101 h. At this point, when the particle size reaches 10 μm, the feed is stopped, and the stirring is turned off, thus obtaining Ni. 0.4 Cu 0.1 Fe 0.2 Mn 0.3 (OH)2 precursor.

[0144] The above Ni 0.4 Cu 0.1 Fe 0.2 Mn 0.3 (OH)₂ precursor powder and sodium carbonate were weighed and mixed at a mass ratio of 1.5:0.79, ground, and then calcined in an air or oxygen atmosphere at a rate of 3°C / min from room temperature. -1 The temperature was rapidly increased to 950℃ and held for 7 hours, then decreased to 855℃ and held for 15 hours. Finally, the furnace was cooled to room temperature to obtain the P2-O3 composite phase Na. 0.82 Ni 0.4 Cu 0.1 Fe 0.2 Mn 0.3 (OH)2 cathode material.

[0145] Comparative Example 1

[0146] S1 is based on the chemical formula Ni of the copper-containing precursor. 0.27 Cu 0.03 Fe 0.3 Mn 0.4(OH)₂, i.e., in the general chemical formula, a = 0.27, b = 0.03, c = 0.4, d = 0.3, β = 0. Nickel sulfate, ferrous sulfate, and manganese nitrate were dissolved in water at a molar ratio of 0.27:0.3:0.4 to prepare a nickel-iron-manganese solution with a total concentration of 2.5 mol / L; copper sulfate was dissolved in water to prepare a copper salt solution with a copper concentration of 0.4 mol / L; sodium hydroxide was dissolved in water to prepare a sodium hydroxide solution with a concentration of 5 mol / L as a precipitant; and ammonia gas was dissolved in water to prepare an ammonia solution with a concentration of 5 mol / L as a complexing agent.

[0147] S2 divides the nickel-iron-manganese liquid into a first salt solution and a second salt solution, and the copper salt solution into a first copper salt solution and a second copper salt solution;

[0148] S3 controls the temperature inside the reactor (including the reactor body and the reactor lid, with the lid on the reactor body; a first feed inlet is located at the end of the reactor body near the lid, and a second feed inlet is located at the end of the reactor body away from the lid) at 70℃. Nitrogen gas is continuously introduced into the sedimentation reactor while stirring is maintained. The first salt solution, alkali solution, ammonia solution, and copper solution are fed in a parallel flow; the first copper salt solution is fed through the first feed inlet, and the first salt solution, alkali solution, and ammonia solution are fed through the second feed inlet. The total metal ion content of the first salt solution and the first copper salt is controlled. The ratio of the total molar feed rate to the molar feed rate of sodium hydroxide in the precipitant was 1:2.2. Specifically, the feed rate of the first salt solution was 10 L / min, the feed rate of the first copper salt was 0.773 L / min, and the feed rate of sodium hydroxide was 1.324 L / min. The ammonia concentration in the reactor was controlled at 0.18 mol / L. After the reaction lasted for 4 hours, the sodium hydroxide feed rate was reduced (to 1.192 L / min), and the reaction was continued for another 2 hours to obtain seed crystals.

[0149] After obtaining seed crystals in S4, the feed continued, with the second salt solution fed at a rate of 20 L / min, the second copper salt at 1.446 L / min, and the sodium hydroxide at 2.3 L / min. The ammonia concentration in the reactor was maintained at 0.14 mol / L, and the precipitation reaction was maintained for 87 hours. Then, the feed was stopped and the stirring was turned off, yielding Ni. 0.27 Cu 0.03 Fe 0.3 Mn 0.4 (OH)2 precursor.

[0150] Comparative Example 2

[0151] S1 is based on the chemical formula Ni of the copper-containing precursor. 0.27 Cu 0.03 Fe 0.3 Mn 0.4(OH)₂, i.e., in the general chemical formula, a = 0.27, b = 0.03, c = 0.4, d = 0.3, β = 0. Nickel sulfate, ferrous sulfate, and manganese nitrate were dissolved in water at a molar ratio of 0.27:0.3:0.4 to prepare a nickel-iron-manganese solution with a total concentration of 2.5 mol / L. Copper sulfate and disodium ethylenediaminetetraacetate were dissolved in water at a molar ratio of 1:1 / 20 to prepare a copper salt solution with a concentration of 0.4 mol / L. Sodium hydroxide was dissolved in water to prepare a sodium hydroxide solution with a concentration of 5 mol / L as a precipitant, and ammonia gas was dissolved in water to prepare an ammonia solution with a concentration of 5 mol / L as a complexing agent.

[0152] S2 divides the nickel-iron-manganese liquid into a first salt solution and a second salt solution, and the copper salt solution into a first copper salt solution and a second copper salt solution;

[0153] S3 controls the temperature inside the reactor (including the reactor body and the reactor lid, with the lid on the reactor body; a first feed inlet is located at the end of the reactor body near the lid, and a second feed inlet is located at the end of the reactor body away from the lid) at 70°C. Nitrogen gas is continuously introduced into the sedimentation reactor while stirring is maintained. Nickel-iron-copper-manganese liquid, alkaline solution, and ammonia solution are fed in a parallel stream. The first copper salt solution is fed through the first feed inlet, while the first salt solution, alkaline solution, and ammonia solution are fed through the second feed inlet. The total metal ions in the first salt solution and the first copper salt are controlled to be... The molar feed rate to the molar feed rate of sodium hydroxide in the precipitant was 1:2.2. Specifically, the feed rate of the first salt solution was 10 L / min, the feed rate of the first copper salt was 0.773 L / min, and the feed rate of sodium hydroxide was 1.324 L / min. The ammonia concentration in the reactor was controlled at 0.8 mol / L. After the reaction lasted for 4 hours, the sodium hydroxide feed rate was reduced (to 1.192 L / min), and the reaction was continued for another 2 hours to obtain seed crystals.

[0154] After obtaining seed crystals in S4, the feed continued, with the second salt solution fed at a rate of 20 L / min, the second copper salt at 1.446 L / min, and the sodium hydroxide at 2.3 L / min. The ammonia concentration in the reactor was maintained at 0.8 mol / L, and the precipitation reaction was maintained for 87 hours. Then, the feed was stopped and the stirring was turned off, yielding Ni. 0.27 Cu 0.03 Fe 0.3 Mn 0.4 (OH)2 precursor.

[0155] Comparative Example 3

[0156] S1 is based on the chemical formula Ni of the copper-containing precursor. 0.2 Cu 0.2 Fe 0.3 Mn 0.3(OH)₂, i.e., a = 0.2, b = 0.2, c = 0.3, d = 0.3, β = 0. Nickel sulfate, ferrous sulfate, and manganese nitrate were dissolved in water at a molar ratio of 0.27:0.3:0.3 to prepare a nickel-iron-manganese solution with a total concentration of 2.5 mol / L; copper sulfate was dissolved in water to prepare a copper salt solution with a concentration of 0.6 mol / L; sodium hydroxide was dissolved in water to prepare a sodium hydroxide solution with a concentration of 5 mol / L as a precipitant; and ammonia gas was dissolved in water to prepare an ammonia solution with a concentration of 5 mol / L as a complexing agent.

[0157] S2 divides the nickel-iron-manganese liquid into a first salt solution and a second salt solution, and the copper salt solution into a first copper salt solution and a second copper salt solution;

[0158] S3 controls the temperature inside the reactor (including the reactor body and the reactor lid, with the lid on the reactor body; a first feed inlet is located at the end of the reactor body near the lid, and a second feed inlet is located at the end of the reactor body away from the lid) at 70°C. Nitrogen gas is continuously introduced into the sedimentation reactor while stirring is maintained. Nickel-iron-manganese liquid, alkaline solution, and ammonia solution are fed in a parallel flow, with the first copper salt solution fed through the first feed inlet, and the first salt solution, alkaline solution, and ammonia solution fed through the second feed inlet. The total metal content of the first salt solution and the first copper salt is controlled. The ratio of the total molar feed rate of ions to the molar feed rate of sodium hydroxide in the precipitant is 1:2.1. Specifically, the feed rate of the first salt solution is 6 L / min, the feed rate of the first copper salt is 5 L / min, and the feed rate of sodium hydroxide is 1.43 L / min. The ammonia concentration in the system of the reactor is controlled at 0.1 mol / L. After the reaction continues for 3 hours, the feed rate of sodium hydroxide is reduced (to 1.3 L / min) and the reaction continues for 2 hours to obtain seed crystals.

[0159] After obtaining seed crystals in S4, the feed continued, with the second salt solution fed at a rate of 12 L / min, the second copper salt at a rate of 10 L / min, and the sodium hydroxide at a rate of 2.67 L / min. The ammonia concentration in the reactor was maintained at 0.15 mol / L, and the precipitation reaction was maintained for 83 hours. Then, the feed was stopped and the stirring was turned off, yielding Ni. 0.2 Cu 0.2 Fe 0.3 Mn 0.3 (OH)2 precursor.

[0160] Comparative Example 4

[0161] S1 is based on the chemical formula Ni of the copper-containing precursor. 0.2 Cu 0.2 Fe 0.3 Mn 0.3(OH)₂, where a = 0.2, b = 0.2, c = 0.3, d = 0.3, and β = 0 in the general chemical formula. Nickel sulfate, ferrous sulfate, and manganese nitrate were dissolved in water at a molar ratio of 0.2:0.3:0.3 to prepare a nickel-iron-manganese solution with a total concentration of 2.5 mol / L. Copper sulfate and sodium tartrate were dissolved in water at a molar ratio of 1:1 / 15 to prepare a copper salt solution with a copper concentration of 0.6 mol / L. Sodium hydroxide was dissolved in water to prepare a sodium hydroxide solution with a concentration of 5 mol / L as a precipitant, and ammonia gas was dissolved in water to prepare an ammonia solution with a concentration of 5 mol / L as a complexing agent.

[0162] S2 divides the nickel-iron-manganese liquid into a first salt solution and a second salt solution, and the copper salt solution into a first copper salt solution and a second copper salt solution;

[0163] S3 controls the temperature inside the reactor (including the reactor body and the reactor lid, with the lid on the reactor body; a first feed inlet is located at the end of the reactor body near the lid, and a second feed inlet is located at the end of the reactor body away from the lid) at 70°C. Nitrogen gas is continuously introduced into the sedimentation reactor while stirring is maintained. Nickel-iron-manganese liquid, alkaline solution, and ammonia solution are fed in a parallel flow, with the first copper salt solution fed through the first feed inlet, and the first salt solution, alkaline solution, and ammonia solution fed through the second feed inlet. The total metal content of the first salt solution and the first copper salt is controlled. The ratio of the total molar feed rate of ions to the molar feed rate of sodium hydroxide in the precipitant is 1:2.1. Specifically, the feed rate of the first salt solution is 6 L / min, the feed rate of the first copper salt is 5 L / min, and the feed rate of sodium hydroxide is 1.43 L / min. The ammonia concentration in the system of the reactor is controlled at 0.7 mol / L. After the reaction continues for 3 hours, the feed rate of sodium hydroxide is reduced (to 1.3 L / min) and the reaction continues for another 3 hours to obtain seed crystals.

[0164] After obtaining seed crystals in S4, the feed continued, with the second salt solution fed at a rate of 12 L / min, the second copper salt at a rate of 10 L / min, and the sodium hydroxide at a rate of 2.67 L / min. The ammonia concentration in the reactor was maintained at 0.7 mol / L, and the precipitation reaction was maintained for 83 hours. Then, the feed was stopped and the stirring was turned off, yielding Ni. 0.2 Cu 0.2 Fe 0.3 Mn 0.3 (OH)2 precursor.

[0165] Performance testing

[0166] The copper-containing precursors obtained in Examples 1 and 2, and Comparative Examples 1 to 4, as well as the composite phase single-crystal sodium-ion battery cathode materials obtained in Examples 1 and 2, were scanned using a field emission scanning electron microscope. The resulting scan images are shown below. Figures 1 to 8 As shown.

[0167] in, Figure 1 and Figure 2 Ni in Embodiments 1 and 2 of the present invention, respectively 0.27 Cu 0.03 Fe 0.3 Mn 0.4 (OH)2-6μm precursor, Ni 0.2 Cu 0.2 Fe 0.3 Mn 0.3 FESEM (Field Emission Scanning Electron Microscope) image of the (OH)2-6μm precursor. From Figure 1 and Figure 2 It can be seen that the obtained copper-containing precursor particles have a specific morphology, appearing as spherical or near-spherical shapes, formed by the cross-linking of a large number of primary particles. No obvious amorphous particles were observed on the surface of the spherical particles. This indicates that by adding a chelating agent in advance to chelate copper ions and optimizing the feed position of the copper salt solution, uniformly doped Cu precursor particles can also be effectively obtained in the ammonia-complexed precipitation system.

[0168] Figure 3 and Figure 4 Ni in Embodiments 1 and 2 of the present invention, respectively 0.27 Cu 0.03 Fe 0.3 Mn 0.4 (OH)2-6μm precursor, Ni 0.2 Cu 0.2 Fe 0.3 Mn 0.3 FESEM image of P2-O3 type monocrystalline sodium-ion battery cathode material obtained by passing (OH)2-6μm precursor through a specific high and low temperature sintering process. Figure 3 and Figure 4 It is known that the particles obtained after sintering are large single crystal particles, which ensures the uniform distribution of elements and the stable structure of the single crystal cathode material. In addition, the single crystal particles have good dispersion and smooth surfaces, which avoids the occurrence of intergranular cracks and ensures stable contact between the cathode and the electrolyte during charging / discharging.

[0169] Figures 5 to 8 The images shown are FESEM images of the copper-containing precursors corresponding to Comparative Examples 1-2 of Embodiment 1 and Comparative Examples 3-4 of Embodiment 2 of the present invention. Figures 5 to 8Observations show that the particles of this type of precursor do not have a specific morphology and are amorphous. They are formed by a large number of loose primary particles, and no regular spherical or near-spherical particles can be seen. This indicates that without optimizing the position of the copper inlet and simply using ammonia to complex copper ions, it is difficult to form a homogeneous precipitation system, resulting in the inability to obtain a stable and controllable regular precursor.

[0170] Furthermore, tests show that the precursors prepared in the other embodiments all have spherical or near-spherical characteristics, and the cathode materials obtained by sintering all exhibit single-crystal particle characteristics and have P2-O3 composite dual phases.

[0171] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for preparing a copper-containing precursor, characterized in that, Includes the following steps: Based on the general chemical formula of copper-containing precursors Ni a Cu b Mn c Fe d M β X, prepare copper salt solutions and salt solutions containing nickel, iron, manganese and M respectively; wherein M includes at least one of titanium, zirconium, antimony, zinc, tin, magnesium, calcium and aluminum, X is an anion, a+b+c+d+β=1, and the copper salt solutions contain chelating agents; The salt solution containing nickel, iron, manganese and M is divided into a first salt solution and a second salt solution, and the copper salt solution is divided into a first copper salt solution and a second copper salt solution. The first salt solution and the first copper salt solution are mixed with a precipitant and a complexing agent to carry out a first precipitation reaction to obtain seed crystals. The second salt solution and the second copper salt solution are added to the seed crystal to carry out a second precipitation reaction to obtain the copper-containing precursor. The first precipitation reaction and the second precipitation reaction are carried out in a reaction vessel, which includes a vessel body and a vessel cover. The vessel cover is disposed on the vessel body. A first feed inlet is opened at one end of the vessel body near the vessel cover, and a second feed inlet is opened at one end of the vessel body away from the vessel cover. The first inlet is used to feed the copper salt solution; the second inlet is used to feed the salt solution containing nickel, iron, manganese, and M.

2. The preparation method according to claim 1, characterized in that, The ratio of the molar amount of the chelating agent to the molar content of copper ions in the copper salt solution is 0.02~1.5:

1.

3. The preparation method according to claim 1, characterized in that, The chelating agent comprises at least one of sodium citrate, disodium ethylenediaminetetraacetate, ethylenediaminetetraacetic acid, sodium diethylenetriaminepentacarboxylate, sodium aminotriacetate, citric acid, ammonium citrate, and tartaric acid; and / or The complexing agent includes ammonia; and / or The precipitant comprises a first precipitant and a second precipitant, wherein the first precipitant comprises at least one of sodium hydroxide solution and potassium hydroxide solution, and the second precipitant comprises at least one of sodium carbonate solution, sodium bicarbonate solution, sodium oxalate solution, and oxalic acid solution; and / or The salts in the copper salt solution and the salt solutions containing nickel, iron, manganese, and M are at least one of sulfate, nitrate, acetate, and chlorate.

4. The preparation method according to claim 3, characterized in that, The ratio of the total molar feed rate of metal ions in the copper salt solution and the salt solution containing nickel, iron, manganese, and M to the molar feed rate of the first precipitant is 1:1.8 to 2.4; and / or The ratio of the total molar feed rate of metal ions in the copper salt solution and the salt solution containing nickel, iron, manganese, and M to the molar feed rate of the second precipitant is 1:1.1 to 1.

5.

5. The preparation method according to any one of claims 1-4, characterized in that, The copper-containing precursor has a particle size of 3μm to 20μm, and the radius ratio of the seed crystal to the copper-containing precursor is 0.1 to 0.6:

1.

6. A copper-containing precursor, characterized in that, The general chemical formula of the copper-containing precursor is Ni. a Cu b Mn c Fe d M β X, M includes at least one of titanium, zirconium, antimony, zinc, tin, magnesium, calcium, and aluminum, where X is an anion and a+b+c+d+β=1; the copper-containing precursor is prepared by the preparation method according to any one of claims 1 to 5.

7. A sodium-ion battery cathode material, characterized in that, The copper-containing precursor prepared by any one of claims 1 to 5 is mixed with sodium salt and calcined.

8. The sodium-ion battery cathode material as described in claim 7, characterized in that, The sodium-ion battery cathode material is a single-crystal large particle of P2-O3 composite phase, and the molar ratio of sodium ions in the sodium salt to metal ions in the copper-containing precursor is 0.8~0.9:1; and / or The calcination process includes: heating to 930℃~1100℃ at a rate of 5℃ / min~10℃ / min, calcining for 4h~7h, and then cooling to 800℃~910℃ and calcining for 10h~15h.

9. A sodium-ion battery, characterized in that, Includes the sodium-ion battery cathode material as described in claim 7 or 8.

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