A multi-metal co-regulated layered oxide sodium-ion battery cathode material, a preparation method and application thereof

Abstract

The application provides a multi-metal co-regulated layered oxide sodium ion battery positive electrode material and a preparation method and application thereof. 0.8 Ni 0.33‑x‑y‑z Cu x Zn y Fe z Mn 0.6 Mg 0.07 O2 (0<=x<0.33, 0<=y<0.33, 0<x+y+z<0.33). The positive electrode material provided by the application exhibits excellent performance, including long cycle stability and low cost price, and is a very valuable sodium ion battery positive electrode material; in addition, the positive electrode material provided by the application successfully constructs a P2 / O3 two-phase composite structure, and the electrochemical performance of the material is improved through complementation of the structure.

Description

Technical Field

[0001] This invention belongs to the field of sodium-ion battery technology, specifically relating to a multi-metal co-regulated layered oxide sodium-ion battery cathode material with excellent electrochemical performance, its preparation method, and its application. Background Technology

[0002] With societal development, the demand for energy is increasing daily. Under these circumstances, limited traditional fossil fuels can no longer meet the long-term needs of human development. Especially in recent years, the continuous exploitation of fossil fuels has led to increasingly serious energy crises and environmental pollution. To better adapt to societal development and achieve long-term stability for humanity, the exploration of sustainable energy is particularly important and urgent. Recently, renewable energy sources such as wind, hydro, and tidal power have received widespread attention due to their clean and pollution-free characteristics, and have been applied in some regions. However, constrained by regional and intermittent limitations, they are difficult to achieve long-term development. Therefore, exploring more sustainable, efficient, and portable energy storage systems is of far-reaching significance. Thus, through continuous research and development by scientists, lithium-ion batteries, as energy storage devices with high electrochemical capacity and long cycle stability, have gradually developed and ultimately achieved successful commercial application, entering the production and daily lives of millions of households as energy storage devices. However, the limited lithium reserves and the surge in demand for energy vehicles and other devices in recent years have led to a continuous increase in lithium prices, which is detrimental to long-term social development. Therefore, there is a need to develop lower-consumption, high-performance, and sustainable energy storage devices. During research, sodium, a member of the same group as lithium, was found to possess many excellent properties, such as abundant sodium reserves and similar physicochemical properties to lithium. Furthermore, their material systems are also quite similar, making sodium considered the most promising next-generation energy storage device to replace lithium-ion batteries. However, the larger radius of sodium ions compared to lithium ions makes migration more difficult during electrochemical cycling and can easily cause structural collapse. Therefore, it is necessary to find more suitable cathode materials to mitigate these adverse effects. Transition metal layered oxide materials have been widely studied as cathode materials for sodium-ion batteries due to their high operating voltage and electrochemical capacity. However, the complex phase transition processes during cycling limit their commercialization. Therefore, more suitable modification strategies need to be designed to obtain high-performance, long-term stable sodium-ion battery cathode materials. Summary of the Invention

[0003] In summary, the technical problem that this invention aims to address is to provide a multi-metal co-regulated layered oxide sodium-ion battery cathode material and its preparation method. The cathode material provided by this invention has excellent cycle stability, and the entire synthesis process is simple and has a high yield.

[0004] To achieve its objectives, the present invention employs the following technical solution:

[0005] This invention first discloses a multi-metal co-regulated layered oxide sodium-ion battery cathode material, the chemical formula of which is Na. 0.8 Ni 0.33-x-y-z Cu x Zn y Fe z Mn 0.6 Mg 0.07 O2(0≤x<0.33, 0≤y<0.33, 0<x+y+z<0.33).

[0006] The multi-metal co-regulated layered oxide sodium-ion battery cathode material can be prepared and synthesized by sol-gel method or by solid-phase synthesis method.

[0007] The steps for preparing multi-metal co-regulated layered oxide sodium-ion battery cathode materials using the sol-gel method are as follows:

[0008] Step 11: Dissolve the sodium source compound, nickel source compound, copper source compound, zinc source compound, iron source compound, manganese source compound, and magnesium source compound in deionized water according to the molar ratio and stir continuously until uniformly mixed. Then place it in a constant temperature oil bath and stir continuously until the solvent is evaporated. Then place it in an oven for further high-temperature drying. After cooling to room temperature, the precursor is obtained.

[0009] Step 12: Grind the precursor in a mortar to obtain precursor powder;

[0010] Step 13: Perform segmented calcination on the precursor powder to obtain the multi-metal co-regulated layered oxide sodium-ion battery cathode material Na. 0.8 Ni 0.33-x-y-z Cu x Zn y Fe z Mn 0.6 Mg 0.07 O2.

[0011] The steps for preparing multi-metal co-regulated layered oxide sodium-ion battery cathode materials using a solid-state method are as follows:

[0012] Step 21: Place the sodium source compound, nickel source compound, copper source compound, zinc source compound, iron source compound, manganese source compound, and magnesium source compound in a mortar according to the molar ratio in the chemical formula, and grind until fully mixed to obtain a mixture powder;

[0013] Step 22: Compress the mixture powder using a tablet press to make the samples more compact and obtain the precursor;

[0014] Step 23: Perform segmented calcination on the precursor to obtain the multi-metal co-regulated layered oxide sodium-ion battery cathode material Na. 0.8 Ni 0.33-x-y-z Cu x Zn y Fe z Mn 0.6 Mg 0.07 O2.

[0015] When using the sol-gel method: the sodium source compound is one or more of sodium oxalate, sodium nitrate, sodium chloride, sodium acetate, and sodium citrate; the nickel source compound is one or more of nickel oxalate, nickel nitrate, nickel chloride, nickel acetate, and nickel sulfate; the copper source compound is one or more of copper oxalate, copper nitrate, copper chloride, copper acetate, and copper sulfate; the zinc source compound is one or more of zinc oxalate, zinc nitrate, zinc chloride, zinc acetate, and zinc sulfate; the iron source compound is one or more of ferric oxalate, ferric nitrate, ferric chloride, ferric acetate, and ferric sulfate; the manganese source compound is one or more of manganese oxalate, manganese nitrate, manganese chloride, manganese acetate, and manganese sulfate; the magnesium source compound is one or more of magnesium oxalate, magnesium nitrate, magnesium chloride, magnesium acetate, and magnesium sulfate; and the chelating agent is one or more of citric acid, oxalic acid, tartaric acid, and ethylenediaminetetraacetic acid.

[0016] When using the solid-phase method: the sodium source compound is one or more of sodium nitrate, sodium chloride, sodium acetate, sodium citrate, sodium carbonate, and sodium oxide; the nickel source compound is one or more of nickel nitrate, nickel chloride, nickel acetate, nickel sulfate, nickel carbonate, and nickel oxide; the copper source compound is one or more of copper nitrate, copper chloride, copper acetate, copper sulfate, copper carbonate, and copper oxide; the zinc source compound is one or more of zinc nitrate, zinc chloride, zinc acetate, zinc sulfate, zinc carbonate, and zinc oxide; the iron source compound is one or more of ferric nitrate, ferric chloride, ferric acetate, ferric sulfate, ferric carbonate, and ferric oxide; the manganese source compound is one or more of manganese nitrate, manganese chloride, manganese acetate, manganese sulfate, manganese carbonate, and manganese oxide; and the magnesium source compound is one or more of magnesium nitrate, magnesium chloride, magnesium acetate, magnesium sulfate, magnesium carbonate, and magnesium oxide.

[0017] Preferably, the segmented calcination method described in step 13 or step 23 is as follows: in an air atmosphere, first heat to 350-600℃ at a heating rate of 2-10℃ / min and hold for 4-10h, then heat to 800-1000℃ at a heating rate of 2-10℃ / min and hold for 10-24h, and obtain the final sample after cooling to room temperature.

[0018] The present invention also prepares a sodium-ion battery positive electrode sheet, which is prepared by positive electrode material, conductive additive, binder and related solvent, wherein the positive electrode material is selected from the multi-metal co-regulated layered oxide sodium-ion battery positive electrode material.

[0019] The present invention also discloses a sodium-ion battery, which is composed of the above-prepared positive electrode sheet, separator, electrolyte and negative electrode metallic sodium, and has shown great application prospects in many energy storage devices, such as electric vehicles, wind power generation, solar power generation, smart grid peak shaving, distributed power stations or communication bases, etc.

[0020] Compared with the prior art, the beneficial effects of the present invention are reflected in:

[0021] This invention provides a layered oxide sodium-ion battery cathode material with excellent electrochemical performance, the chemical formula being Na. 0.8 Ni 0.33-x-y-z Cu x Zn y Fe z Mn 0.6 Mg 0.07 O2 (0≤x<0.33,0≤y<0.33,0<x+y+z<0.33). The cathode material prepared by this invention exhibits long cycle stability and low cost, further promoting the research and development of cathode materials for sodium-ion batteries. Simultaneously, the cathode material provided by this invention has a P2 / O3 two-phase composite structure, which better maintains structural stability and promotes sodium ion transport, thereby achieving superior electrochemical performance. Furthermore, the cathode material provided by this invention has a simple synthesis method, excellent electrochemical performance, and is easy to mass-produce. Attached Figure Description

[0022] Figure 1 The image shown is an SEM image of the target product obtained in Example 1.

[0023] Figure 2 The image shows the XRD pattern of the target product obtained in Example 1.

[0024] Figure 3 The charge-discharge curve of the target product obtained in Example 1 at a current density of 0.1C is shown.

[0025] Figure 4 The image shows the cyclic stability spectrum of the target product obtained in Example 1 at a current density of 1C.

[0026] Figure 5 The image shows the XRD pattern of the target product obtained in Example 2.

[0027] Figure 6 The charge-discharge curve of the target product obtained in Example 2 at a current density of 1C is shown.

[0028] Figure 7 The image shows the XRD pattern of the target product obtained in Example 3.

[0029] Figure 8 The charge-discharge curve of the target product obtained in Example 3 at a current density of 1C is shown.

[0030] Figure 9 The charge-discharge curve of the target product obtained in Example 4 at a current density of 0.1C is shown. Detailed Implementation

[0031] This invention provides a multi-metal co-regulated layered oxide sodium-ion battery cathode material with excellent electrochemical performance, the chemical formula being Na. 0.8 Ni 0.33-x-y-z Cu x Zn y Fe z Mn 0.6 Mg 0.07 O2, where 0≤x<0.33, 0≤y<0.33, 0<x+y+z<0.33. The sodium-ion battery cathode material provided by this invention is in block form.

[0032] In some specific embodiments of the present invention, the sodium-ion battery cathode material is Na. 0.8 Ni 0.17 Cu 0.07 Zn 0.03 Fe 0.06 Mn 0.6 Mg 0.07 O2. It exhibits the best overall performance and excellent cycle stability at 1C (1C = 170 mAg). -1 The battery retains 80.0% capacity after 200 cycles at the specified current density, which greatly promotes the commercialization of sodium-ion batteries in the future.

[0033] This invention also successfully prepared a sodium-ion battery positive electrode sheet, which is made of active material, conductive additive, binder and solvent, wherein: the positive electrode active material is selected from the above-synthesized multi-metal co-regulated layered oxide sodium-ion battery positive electrode material; the conductive additive is selected from one or more of carbon black, Super-P and Ketjen black; the binder is selected from one or more of polyacrylic acid, sodium carboxymethyl cellulose, polyvinylidene fluoride and sodium alginate; and the solvent is selected from one or more of N-methylpyrrolidone or deionized water.

[0034] The present invention also provides a method for preparing the above-mentioned sodium-ion battery positive electrode sheet, which involves mixing positive electrode material, conductive additives, binders and solvents in a certain proportion, and then preparing the battery positive electrode sheet through subsequent coating and drying processes.

[0035] The specific methods for mixing, coating, and drying in this invention are common preparation methods, which can be followed according to methods known to those skilled in the art.

[0036] This invention also prepares a sodium-ion battery, comprising a positive electrode, a separator, an electrolyte, and a negative electrode of metallic sodium, wherein: the positive electrode uses the aforementioned sodium-ion battery positive electrode. The electrolyte used is a carbonate-based electrolyte with a concentration of 0.5–2 M, preferably 1 M; the solvent in the electrolyte is derived from one or more of dimethyl carbonate, ethylene carbonate, methyl ethyl carbonate, diethyl carbonate, propylene carbonate, and fluorinated ethylene carbonate, preferably a mixed solvent of propylene carbonate and fluorinated ethylene carbonate; the solute in the electrolyte is selected from one or more of sodium perchlorate, sodium bis(trifluoromethanesulfonyl)imide, and sodium hexafluorophosphate, preferably sodium perchlorate. The separator is preferably glass fiber.

[0037] This invention also provides the application of the above-mentioned sodium-ion battery in large-scale energy storage devices such as electric vehicles, solar power generation, wind power generation, smart grid peak shaving, distributed power stations or communication bases.

[0038] The present invention has the following advantages:

[0039] (1) A synthesized multi-metal-doped bulk layered oxide sodium-ion battery cathode material with the chemical formula Na 0.8 Ni 0.33-x-y-z Cu x Zn y Fe z Mn 0.6 Mg 0.07 O2 (0≤x<0.33,0≤y<0.33,0<x+y+z<0.33) has greatly promoted the future commercial development of sodium-ion battery material systems.

[0040] (2) The present invention Na 0.8 Ni 0.33-x-y-z Cu x Zn y Fe z Mn 0.6 Mg 0.07 O2 (0≤x<0.33,0≤y<0.33,0<x+y+z<0.33) cathode material has excellent cycle stability and low cost, making it a promising cathode material for sodium-ion batteries.

[0041] (3) The optimal Na of this invention 0.8 Ni 0.17 Cu 0.07 Zn 0.03 Fe 0.06 Mn 0.6 Mg0.07 O2 cathode material exhibits the best cycle stability at 1C (1C = 170 mAg). -1 After 200 cycles at a current density, its capacity retention rate is 80.0%, making it an ideal cathode material for preparing sodium-ion battery energy storage devices.

[0042] (4) Compared with materials that do not undergo multi-metal regulation, the cathode material synthesized by the method of the present invention has better overall performance.

[0043] To further understand the present invention, the following description, in conjunction with specific embodiments, illustrates the superior performance of the layered oxide sodium-ion battery cathode material provided by the present invention, its preparation method, and its application. The scope of protection of the present invention is not limited by the following embodiments.

[0044] Example 1

[0045] Step 1, Preparation of Na by Sol-Gel Method 0.8 Ni 0.17 Cu 0.07 Zn 0.03 Fe 0.06 Mn 0.6 Mg 0.07 O2 cathode material

[0046] Sodium acetate, nickel acetate, copper acetate, zinc acetate, ferric acetate, manganese acetate, and magnesium acetate were dissolved in deionized water at a molar ratio of 1:2 with citric acid, and the mixture was stirred continuously until homogeneous. The solution was then placed in a 70°C oil bath and stirred until the solvent evaporated. The sample was then transferred to a 150°C oven and dried for another 6 hours. After cooling to room temperature, the sample was removed and ground in a mortar to form a precursor powder.

[0047] The precursor powder was placed in a muffle furnace and calcined in stages under air atmosphere: the first stage of pre-calcination involved a heating temperature of 450℃ at a heating rate of 2℃ / min and a holding time of 6h; the second stage of high-temperature calcination involved a heating temperature of 900℃ at a heating rate of 2℃ / min and a holding time of 15h. After the holding time, the temperature was lowered to room temperature to obtain the target product Na. 0.8 Ni 0.17 Cu 0.07 Zn 0.03 Fe 0.06 Mn 0.6 Mg 0.07 O2.

[0048] Step 2, Preparation of sodium-ion battery positive electrode sheet

[0049] The Na synthesized above 0.8 Ni 0.17 Cu 0.07 Zn 0.03 Fe0.06 Mn 0.6 Mg 0.07 O2 cathode material, SuperP, and polyvinylidene fluoride binder (PVDF) are mixed at a mass ratio of 7:2:1, with a certain amount of N-methylpyrrolidone added as a solvent. After mixing, slurrying, coating, and drying, a mixture containing Na is obtained. 0.8 Ni 0.17 Cu 0.07 Zn 0.03 Fe 0.06 Mn 0.6 Mg 0.07 Sodium-ion battery positive electrode with O2 active material.

[0050] Step 3, assemble with the final product Na 0.8 Ni 0.17 Cu 0.07 Zn 0.03 Fe 0.06 Mn 0.6 Mg 0.07 Sodium-ion batteries using O2 as the positive electrode material.

[0051] The sodium-ion battery positive electrode and metallic sodium negative electrode prepared above were assembled into a sodium-ion battery in a glove box. GF / F was used as the battery separator, and carbonate electrolyte (1M NaClO4 in PC) was selected as the electrolyte.

[0052] Figure 1 The image shown is a SEM image of the cathode material prepared in Example 1. As can be seen from the image, the material has a blocky structure and is uniformly distributed.

[0053] Figure 2 The figure shows the XRD pattern of the cathode material obtained in Example 1. As can be seen from the figure, the synthesized layered oxide cathode material has a P2 / O3 two-phase structure.

[0054] Figure 3 The image shows a sodium-ion battery assembled using the cathode material obtained in Example 1 at 0.1C (1C = 170 mAg). -1 The charge-discharge curves at the specified current density are shown in the figure. As can be seen from the figure, the synthesized material exhibits a capacity of 135.4 mAh / g in sodium-ion batteries. -1 It has a higher discharge specific capacity.

[0055] Figure 4 The figure shows the cycle stability test results of the sodium-ion battery assembled with the cathode material obtained in Example 1 at a current density of 1C. As can be seen from the figure, after 200 cycles, 80.0% of the capacity is still retained.

[0056] Example 2

[0057] The preparation method is the same as in Example 1, except that the proportion of raw materials is adjusted according to Na 0.8 Ni 0.20 Cu 0.07 Zn 0.03 Fe 0.03 Mn 0.6 Mg 0.07 O2 is added in stoichiometric proportions.

[0058] Figure 5 The image shows the Na obtained in Example 2. 0.8 Ni 0.20 Cu 0.07 Zn 0.03 Fe 0.03 Mn 0.6 Mg 0.07 The XRD pattern of the O2 material shows that the synthesized cathode material has good crystallinity and is also a P2 / O3 mixed phase structure.

[0059] Figure 6 The image shows the Na obtained in Example 2. 0.8 Ni 0.20 Cu 0.07 Zn 0.03 Fe 0.03 Mn 0.6 Mg 0.07 Sodium-ion batteries assembled with O2 cathode material operate at 1C (1C = 170 mAg). -1 The charge-discharge curves at the current density are shown in the figure. As can be seen from the figure, the synthesized material exhibits a charge-discharge ratio of 110.3 mAh / g in sodium-ion batteries. -1 The specific discharge capacity.

[0060] Example 3

[0061] The preparation method is the same as in Example 1, except that the proportion of raw materials is adjusted according to Na 0.8 Ni 0.14 Cu 0.07 Zn 0.03 Fe 0.09 Mn 0.6 Mg 0.07 O2 stoichiometric addition

[0062] Figure 7 The image shown is of Na obtained in Example 3. 0.8 Ni 0.14 Cu 0.07 Zn 0.03 Fe 0.09 Mn 0.6 Mg 0.07 The XRD pattern of the O2 material shows that the synthesized cathode material has good crystallinity and is a P2 / O3 two-phase structure.

[0063] Figure 8 The image shown is of Na obtained in Example 3. 0.8 Ni 0.14 Cu 0.07 Zn 0.03 Fe 0.09 Mn 0.6 Mg 0.07 Sodium-ion batteries assembled with O2 cathode material operate at 1C (1C = 170 mAg). -1 The charge-discharge curves at the specified current density are shown in the figure. As can be seen from the figure, the synthesized material exhibits a capacity of 109.1 mAh / g in sodium-ion batteries. -1 The specific discharge capacity.

[0064] Example 4

[0065] Step 1, Preparation of Na by solid-state synthesis 0.8 Ni 0.17 Cu 0.07 Zn 0.03 Fe 0.06 Mn 0.6 Mg 0.07 O2 cathode material

[0066] Sodium carbonate, nickel oxide, copper oxide, zinc oxide, iron oxide, manganese oxide, and magnesium oxide were placed in a mortar according to stoichiometric ratio and ground until fully mixed to obtain a powder mixture. The mixture sample was then compressed into tablets using a tablet press to ensure tighter contact between the samples, yielding a precursor. The precursor was then subjected to staged calcination: the first stage, pre-calcination, was carried out at 450℃ with a heating rate of 2℃ / min for 6 hours; the second stage, high-temperature calcination, was carried out at 900℃ with a heating rate of 2℃ / min for 15 hours. After the second stage, the temperature was lowered to room temperature to obtain the target product, Na. 0.8 Ni 0.17 Cu 0.07 Zn 0.03 Fe 0.06 Mn 0.6 Mg 0.07 O2.

[0067] Step 2, Preparation of sodium-ion battery positive electrode sheet

[0068] The Na prepared above 0.8 Ni 0.17 Cu 0.07 Zn 0.03 Fe 0.06 Mn 0.6 Mg 0.07O2 cathode material, SuperP, and polyvinylidene fluoride binder (PVDF) are mixed at a mass ratio of 7:2:1, with a certain amount of N-methylpyrrolidone added as a solvent. After mixing, slurrying, coating, and drying, a mixture containing Na is obtained. 0.8 Ni 0.17 Cu 0.07 Zn 0.03 Fe 0.06 Mn 0.6 Mg 0.07 Sodium-ion battery positive electrode with O2 as the positive active material.

[0069] Step 3, assemble with Na 0.8 Ni 0.17 Cu 0.07 Zn 0.03 Fe 0.06 Mn 0.6 Mg 0.07 Sodium-ion batteries with O2 as the positive electrode

[0070] The sodium-ion battery positive electrode and the metallic sodium negative electrode prepared above are used to assemble a sodium-ion battery, with GF / F as the battery separator and carbonate electrolyte (1M NaClO4 in PC).

[0071] Figure 9 The image shows a sodium-ion battery assembled using the cathode material obtained in Example 4 at 0.1C (1C = 170 mAg). -1 The charge-discharge curves at the current density are shown in the figure. It can be seen that 126.4 mAh g can be released during the initial cycle. -1 Electrochemical specific capacity.

[0072] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A multi-metal co-regulated layered oxide sodium-ion battery cathode material, characterized in that: The chemical formula of the sodium-ion battery cathode material is Na. 0.8 Ni 0.17 Cu 0.07 Zn 0.03 Fe 0.06 Mn 0.6 Mg 0.07 O2, and the positive electrode material is a P2 / O3 two-phase composite structure.

2. A method for preparing the multi-metal co-regulated layered oxide sodium-ion battery cathode material according to claim 1, characterized in that: Prepared using the sol-gel method or the solid-phase method.

3. The preparation method according to claim 2, characterized in that: The steps for preparing multi-metal co-regulated layered oxide sodium-ion battery cathode materials using the sol-gel method are as follows: Step 11: Dissolve the sodium source compound, nickel source compound, copper source compound, zinc source compound, iron source compound, manganese source compound, and magnesium source compound in deionized water according to the molar ratio and stir continuously until uniformly mixed. Then place it in a constant temperature oil bath and stir continuously until the solvent is evaporated. Then place it in a 150°C oven for further high-temperature drying. After cooling to room temperature, the precursor is obtained. Step 12: Grind the precursor to obtain precursor powder; Step 13: Perform segmented calcination on the precursor powder to obtain the multi-metal co-regulated layered oxide sodium-ion battery cathode material Na. 0.8 Ni 0.17 Cu 0.07 Zn 0.03 Fe 0.06 Mn 0.6 Mg 0.07 O2; The steps for preparing multi-metal co-regulated layered oxide sodium-ion battery cathode materials using a solid-state method are as follows: Step 21: Place the sodium source compound, nickel source compound, copper source compound, zinc source compound, iron source compound, manganese source compound, and magnesium source compound in a mortar according to the molar ratio, and grind until fully mixed to obtain a mixture powder; Step 22: Compress the mixture powder using a tablet press to obtain the precursor; Step 23: Perform segmented calcination on the precursor to obtain the multi-metal co-regulated layered oxide sodium-ion battery cathode material Na. 0.8 Ni 0.17 Cu 0.07 Zn 0.03 Fe 0.06 Mn 0.6 Mg 0.07 O2.

4. The preparation method according to claim 3, characterized in that: When using the sol-gel method: the sodium source compound is one or more of sodium oxalate, sodium nitrate, sodium chloride, sodium acetate, and sodium citrate; the nickel source compound is one or more of nickel oxalate, nickel nitrate, nickel chloride, nickel acetate, and nickel sulfate; the copper source compound is one or more of copper oxalate, copper nitrate, copper chloride, copper acetate, and copper sulfate; the zinc source compound is one or more of zinc oxalate, zinc nitrate, zinc chloride, zinc acetate, and zinc sulfate; the iron source compound is one or more of ferric oxalate, ferric nitrate, ferric chloride, ferric acetate, and ferric sulfate; the manganese source compound is one or more of manganese oxalate, manganese nitrate, manganese chloride, manganese acetate, and manganese sulfate; the magnesium source compound is one or more of magnesium oxalate, magnesium nitrate, magnesium chloride, magnesium acetate, and magnesium sulfate; and the chelating agent is one or more of citric acid, oxalic acid, tartaric acid, and ethylenediaminetetraacetic acid. When using the solid-phase method: the sodium source compound is one or more of sodium nitrate, sodium chloride, sodium acetate, sodium citrate, sodium carbonate, and sodium oxide; the nickel source compound is one or more of nickel nitrate, nickel chloride, nickel acetate, nickel sulfate, nickel carbonate, and nickel oxide; the copper source compound is one or more of copper nitrate, copper chloride, copper acetate, copper sulfate, copper carbonate, and copper oxide; the zinc source compound is one or more of zinc nitrate, zinc chloride, zinc acetate, zinc sulfate, zinc carbonate, and zinc oxide; the iron source compound is one or more of ferric nitrate, ferric chloride, ferric acetate, ferric sulfate, ferric carbonate, and ferric oxide; the manganese source compound is one or more of manganese nitrate, manganese chloride, manganese acetate, manganese sulfate, manganese carbonate, and manganese oxide; and the magnesium source compound is one or more of magnesium nitrate, magnesium chloride, magnesium acetate, magnesium sulfate, magnesium carbonate, and magnesium oxide.

5. The preparation method according to claim 3, characterized in that: The segmented calcination method described in step 13 or step 23 is as follows: In an air atmosphere, first heat the sample to 350-600℃ at a heating rate of 2-10℃ / min and hold it for 4-10 hours, then heat the sample to 800-1000℃ at a heating rate of 2-10℃ / min and hold it for 10-24 hours, and finally obtain the final sample after cooling to room temperature.

6. A sodium-ion battery positive electrode sheet, prepared from a positive electrode material, conductive additives, a binder, and a solvent, characterized in that: The cathode material is selected from the multi-metal co-regulated layered oxide sodium-ion battery cathode material described in claim 1.

7. A sodium-ion battery, comprising a positive electrode, a separator, an organic electrolyte, and a negative electrode of metallic sodium, characterized in that: The positive electrode is the sodium-ion battery positive electrode as described in claim 6.

Images