Interface high-entropy layered oxide sodium-ion battery cathode material and preparation method and application thereof

Abstract

The application provides a layered oxide sodium-ion battery cathode material with an interface high entropy and a preparation method and application thereof. x Fe y Mn z A a B b C c D d O2, wherein x+y+z+a+b+c+d=1, a+b+c+d<=0.1, and a>0, b>0, c>0, d>=0, wherein A is at least one of Y, Zr and Nb, B is at least one of a lanthanide series element or Ta and W, and C and D are at least one of a fourth and fifth period transition metal element. The preparation method of the cathode material is simple and suitable for large-scale production. By adjusting the adding sequence of the doping source, the application utilizes the characteristics of the fourth and fifth period transition metal elements tending to surface segregation, constructs an interface high entropy spinel structure through trace multi-element doping, and the distribution of each doping element is uniform, the interface structure stability of the material is enhanced, and the cycle performance of the material is effectively improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of chemical power sources, and particularly relates to preparation and application of a kind of interface high-entropy layered oxide sodium-ion battery cathode material. BACKGROUND

[0002] Lithium-ion batteries are the most widely used secondary batteries at present, and have been widely used in mobile phones, computers and electric vehicles, etc. However, the lithium resources are insufficient and unevenly distributed globally, which seriously limits the large-scale use of lithium-ion batteries. In contrast, sodium-ion batteries are considered to have good application prospects in large-scale energy storage due to the abundant sodium resources and low cost.

[0003] Among the many sodium-ion battery cathode materials, layered transition metal oxides Na x TMO2 (TM is a transition metal) has been widely concerned by researchers due to its high specific capacity, high energy density, simple preparation method, etc. However, the layered transition metal oxides will undergo serious interface side reactions during the cycling process due to the dissolution of transition metals and the decomposition of electrolyte catalyzed by transition metals. Such adverse interface side reactions will lead to the degradation of the layered structure of the interface, resulting in poor interface structure stability of this kind of material in the long cycling process, producing cracks, and thus the electrolyte will undergo more serious side reactions through the cracks and the interior of the cathode particles, thereby restricting its performance in practical application. In order to improve the interface structure stability of this kind of material, a coating layer is usually introduced into the layered transition metal oxide layer to stabilize the interface structure, thereby improving the cycling performance and inhibiting the capacity decay. However, the construction method of the coating layer is generally complex, and due to the poor air stability of the layered transition metal oxides, the material is easily disabled during the coating post-processing process. However, the construction of surface high-entropy structure can realize the modification in one step without post-processing process, simplifying the process and avoiding the failure of the synthesized cathode material in the air exposure, so this method is more simple, convenient and efficient. SUMMARY

[0004] In view of this, the application solves the above problems by modifying the layered positive electrode material through the method of constructing an interface high-entropy layer. In the synthesis process, heavy elements are directly doped with multiple trace elements, the preparation method is simple, the effect is significant, and through the optimization of the process, the heavy elements tend to segregate on the surface, so that a high-entropy layer is formed at the interface layer. The high-entropy layer is beneficial to improve the stability of the structure, avoid the structural degradation of the layered phase on the surface during the cycle process, thereby avoiding the dissolution of transition metals and the catalytic decomposition of transition metals on the electrolyte, improving the interface stability of the material, avoiding the generation of surface cracks, solving the capacity attenuation caused by the interface problem, and effectively improving the long cycle performance of the material. And the high-entropy interface layer is beneficial to improve the solid solubility of heavy elements, can reduce the existence of impurities, and improve the electrochemical performance. Traditional high-entropy materials require similar content of each element in the composition, and too little content of the doped element cannot achieve high-entropy effect, and too much content will not provide enough active electric pairs, which greatly limits the capacity of high-entropy materials. The application selects heavy elements and optimizes the doping process, which is different from traditional high-entropy materials. The construction of the interface high-entropy layer ensures the content of sufficient active elements, so that the stability of the structure can be improved without losing capacity. Moreover, the construction of the interface high-entropy layer reduces the content of the interface active elements, avoids the catalytic decomposition of high-valence active elements on the electrolyte and the dissolution of active elements.

[0005] In order to achieve the above-mentioned application purposes, the application provides the following technical solutions:

[0006] An interface high-entropy layered oxide sodium-ion battery positive electrode material, characterized in that the chemical formula is expressed as NaNi x Fe y Mn z A a B b C c D d O2, wherein x+y+z+a+b+c+d=1, a+b+c+d≤0.1, and a>0, b>0, c>0, d≥0, wherein A is at least one of Y, Zr, and Nb, B is at least one of lanthanide elements or Ta and W, C and D are at least one of fourth and fifth period transition metal elements.

[0007] Preferably, 0.01≤a+b+c+d≤0.05.

[0008] The ratio of A, B, C needs to meet a:b:c = 1-2:1-2:1-2, preferably 1-1.3:1-1.3:1-1.3; if D element exists, A, B, C, D meet a:b:c:d = 1-2:1-2:1-2:1-2, preferably 1-1.3:1-1.3:1-1.3:1-1.3. The ratio of A, B, C, (D) elements meets the above ratio, that is, the contents of A, B, C, (D) are close, and it is easier to form a spinel structure at the interface, so that the structural stability is increased while avoiding the degradation of the layered phase in the cycle process.

[0009] The application also provides a preparation method of the above-mentioned interfacial high-entropy layered oxide sodium-ion battery cathode material, comprising the following steps:

[0010] (S1) adding a sodium source, a nickel source, an iron source, a manganese source and an element A source, and mixing uniformly to obtain a mixture I;

[0011] (S2) performing first calcination on the mixture I at 400-600 DEG C, adding an element B and C source after cooling, mixing uniformly to obtain a mixture II; optionally, after cooling, adding an element D source in addition to the element B and C source;

[0012] (S3) performing second calcination on the mixture II at 800-1200 DEG C, and obtaining the interfacial high-entropy layered oxide sodium-ion battery cathode material after cooling.

[0013] Since the temperature of the first calcination is low and the particle size of the precursor is large, the A source is difficult to diffuse into the bulk phase in the first calcination, and an intermediate product of a spinel phase with A uniformly enriched on the surface is obtained. A uniformly enriched on the surface provides more favorable doping sites for B, C and (D) elements, and since the radii are similar, after adding B, C and (D) sources, B, C and D elements tend to preferentially combine with A in the process of second calcination, thereby avoiding the situation that the concentration of a certain doping source is too high in a local area, and making the element distribution more uniform.

[0014] If A, B, C and (D) sources are added together in the first mixing step, a layered oxide cathode modified by trace doping of A, B, C and D will be obtained. Since the doping of non-active elements can stabilize the structure and improve the cycle performance, but cannot avoid the degradation of the interface structure in the cycle process, and does not reduce the content of the interface active element, the problems of catalytic decomposition of electrolyte and dissolution of transition metal are still serious, and the key problem of failure of the layered oxide cathode is not solved, so the modification effect is poorer than that of the interfacial high-entropy layered oxide cathode. If A, B, C and D sources are added together in the second mixing step, since the amount added is too small, it is easy to appear uneven mixing and the concentration of a certain doping source is too high in a local area, which leads to uneven distribution of the surface high-entropy layer and makes the modification effect unsatisfactory.

[0015] Furthermore, the sodium source is selected from at least one of sodium carbonate, sodium bicarbonate, sodium acetate, sodium oxalate, sodium hydroxide, sodium oxide, sodium peroxide, and sodium nitrite; the nickel, iron, and manganese source materials are selected from at least one of oxides, hydroxides, sulfates, nitrates, carbonates, acetates, oxalates, and their hydrated compounds of nickel, iron, and manganese.

[0016] The doping element A source, B source, C source, and D source required for the positive electrode according to the present invention are selected from at least one of the oxides, hydroxides, sulfates, nitrates, carbonates, acetates, oxalates, and their hydrated compounds of the doping element.

[0017] The sodium source materials are fed according to the stoichiometric ratio determined by the general structural formula, while the sodium source materials are fed at a ratio of 100%-120% of the stoichiometric ratio, and then mixed evenly to form a mixture.

[0018] In the above methods, the purity of the raw materials is greater than 99%, preferably ≥99.9%.

[0019] In the above methods, there is no particular limitation on the mixing method, including manual mixing or mechanical mixing, specifically selected from at least one of mechanical ball milling, manual grinding, and mechanical grinding, wherein the ball milling time is 1-50 hours, the ball mill speed is 200-1000 rpm, the manual grinding time is 10-60 minutes, and the mechanical grinding time is 10-60 minutes.

[0020] The calcination atmosphere is at least one of oxygen, air, nitrogen, and argon. The primary calcination temperature is 300-600℃, the holding time is 1-10h, the heating rate is 1-10℃ / min, and the cooling rate is 1-10℃ / min, or the furnace is cooled. The secondary calcination temperature is 800-1200℃, the holding time is 5-40h, the heating rate is 1-10℃ / min, and the cooling rate is 1-10℃ / min, or the furnace is cooled.

[0021] The present invention also provides a sodium-ion battery, wherein the positive electrode comprises the above-mentioned layered oxide sodium-ion battery positive electrode material with high interfacial entropy.

[0022] The high-entropy layered oxide sodium-ion battery cathode material provided by this invention can effectively achieve surface modification of dopant elements A, B, and C. Since the radii of transition metal elements in periods 5 and 6 are relatively large, their doping into the bulk phase leads to significant lattice distortion, which is detrimental to structural stability. Therefore, period 5 and 6 transition metal elements are more suitable for surface modification. After the first calcination, a spinel phase intermediate of nickel-iron-manganese is formed. Adding dopant elements A, B, and C at this point results in slow diffusion rates, making it difficult for them to diffuse into the bulk phase. This makes it difficult to form a uniform layered oxide structure during the second calcination, ultimately resulting in a high-entropy spinel phase structure on the surface. On the other hand, period 5 and 6 transition metal elements, due to their large radii, are generally difficult to dopant and have limited solid solubility, easily forming impurity phases. However, the high-entropy interfacial design, due to the increased entropy, reduces the Gibbs free energy during synthesis, thus facilitating the solid solution reaction and preventing the formation of impurity phases.

[0023] The second step involves adding sources A, B, and C during calcination. This utilizes the slow diffusion rate of elements from the fifth and sixth periods, making it difficult for them to diffuse uniformly into the interior of the large particles generated after the first calcination, thus achieving surface enrichment of the elements.

[0024] The beneficial effects of this invention are as follows:

[0025] First, the high-entropy interfacial layer in the method of this invention can be formed directly during the calcination of materials without the need for additional modification processes. The synthesis process is simple and the production efficiency is high. Furthermore, all raw materials used in this invention are readily available, non-toxic, and inexpensive. The production process requires no special protection, has good compatibility with existing production equipment, and is suitable for large-scale production.

[0026] Second, the high-entropy layered cathode material prepared by this invention has significantly improved cycle performance with less capacity loss because the inert elements are all segregated on the surface and are trace doped.

[0027] Third, the high-entropy layered cathode material prepared by this invention has a stable high-entropy interface structure, which improves the interface stability of the material during cycling, avoids the degradation of the layered phase at the interface, and effectively improves the long-cycle performance of the material. Attached Figure Description

[0028] Figure 1 The XRD pattern of the positive electrode prepared in Example 1.

[0029] Figure 2 The image shows the SEM spectrum of the positive electrode prepared in Example 1.

[0030] Figure 3 The graph shows the cycle performance of the coin cells assembled with the cathode materials of Example 1 and Comparative Example 1.

[0031] Figure 4 The image shows the HAADF-STEM image of the positive electrode prepared in Example 1. Detailed Implementation

[0032] The high-entropy layered oxide sodium-ion battery cathode material of the present invention will be further described below with reference to specific embodiments and accompanying drawings. However, it should be understood that the scope of protection of the present invention is not limited to the following embodiments.

[0033] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0034] Example 1

[0035] (S1) Weigh 0.105 mmol sodium carbonate, 0.02475 mmol nickel-iron-manganese hydroxide precursor (NiFeMn(OH)2), 0.012375 mmol ferric oxide, and 0.000165 mmol yttrium oxide and mix them to obtain mixture I;

[0036] (S2) Place mixture I in a magnetic boat and then place it in a muffle furnace for the first calcination at a heating rate of 5℃ / min. After reaching 450℃, hold the temperature for 5 hours and then cool to room temperature. Grind and mix the product after the first calcination with 0.00033 mmol cerium dioxide and 0.000165 mmol lanthanum oxide.

[0037] (S3) The mixture is then placed in a muffle furnace for a second calcination at a heating rate of 5℃ / min. After reaching 1000℃, it is held for 15h and then cooled to room temperature to obtain the iron-based sodium oxide cathode material for sodium-ion batteries.

[0038] (S4) The obtained positive electrode material, conductive additive SP, and binder PVDF are mixed in 80 parts, 10 parts, and 10 parts by weight, respectively, and dissolved in solvent NMP. After stirring, a uniform slurry is obtained. The slurry is then uniformly coated on carbon-coated aluminum foil using a 200μm scraper, dried, and sliced ​​to obtain the positive electrode sheet.

[0039] Figure 1 The XRD pattern of the cathode material prepared in Example 1 shows that the high-entropy material at the interface still maintains the structure of the O3 phase and can be classified as the R3m type space group.

[0040] Figure 2 The image shows the SEM image of the cathode material prepared in Example 1. It can be seen that the high-entropy cathode material at the interface is in the form of stacked sheets with relatively uniform particle size.

[0041] Figure 3The graph shows the cycle performance of the coin cell cathode materials of Example 1 and Comparative Example 1.

[0042] Figure 4 The HAADF-STEM image of the positive electrode prepared in Example 1 shows that the interface has a spinel phase structure.

[0043] Example 2

[0044] The operation steps are the same as in Example 1, except that the mixture of 0.00033 mmol cerium dioxide, 0.000165 mmol yttrium trioxide, and 0.000165 mmol lanthanum oxide is replaced with 0.00033 mmol molybdenum dioxide, 0.000165 mmol niobium pentoxide, and 0.000165 mmol tantalum pentoxide. Niobium pentoxide is added as element A source in step (S1), while other doping element sources are added after the first calcination in step (S2).

[0045] Example 3

[0046] The operation steps are the same as in Example 1, except that the total doping ratio of Ce, Y, and La is increased from 0.01 (a+b+c=0.01) to 0.05 (a+b+c=0.05).

[0047] Example 4

[0048] The operation steps are the same as in Example 2, except that the doping amounts of Mo, Ta, and Nb are increased from 0.01 (a+b+c=0.01) to 0.15 (a+b+c=0.1).

[0049] Example 5

[0050] The operation steps are the same as in Example 1, except that the mixture of 0.00033 mmol cerium dioxide, 0.000165 mmol yttrium trioxide, and 0.000165 mmol lanthanum oxide is replaced with 0.00025 mmol molybdenum dioxide, 0.000125 mmol tantalum pentoxide, 0.000125 mmol niobium pentoxide, and 0.000125 mmol zirconium dioxide. Niobium pentoxide and zirconium dioxide are added as source A in step (S1), and other dopant sources are added in step (S2).

[0051] Example 6

[0052] The operating steps are the same as in Example 1, except that the mixture of 0.00033 mmol cerium dioxide, 0.000165 mmol yttrium trioxide, and 0.000165 mmol lanthanum oxide is replaced with 0.00025 mmol zirconium dioxide, 0.000125 mmol tantalum pentoxide, and 0.00025 mmol tungsten oxide.

[0053] Example 7

[0054] The operating steps are the same as in Example 1, except that the mixture of 0.00033 mmol cerium dioxide, 0.000165 mmol yttrium trioxide, and 0.000165 mmol lanthanum oxide is replaced with 0.00025 mmol zirconium dioxide, 0.000125 mmol tantalum pentoxide, and 0.00025 mmol ruthenium dioxide.

[0055] Example 8

[0056] The operation steps are the same as in Example 1, except that the heat preservation time for the second calcination is extended from 15 hours to 20 hours.

[0057] Example 9

[0058] The operation steps are the same as in Example 1. The difference is that in step (S2), in addition to cerium dioxide and lanthanum oxide doping sources, 0.000165 mmol of tantalum pentoxide is added as the D source.

[0059] Comparative Example 1

[0060] Preparation of NaNi 0.25 Fe 0.5 Mn 0.25 For the O2 layered cathode material, weigh out 0.105 mmol sodium carbonate, 0.025 mmol nickel-iron-manganese hydroxide precursor, and 0.0125 mmol ferric oxide, mix them, and grind them manually for 1 hour.

[0061] The ground powder was placed in a magnetic boat and then calcined in a muffle furnace at a heating rate of 3°C / min until it reached 450°C. The temperature was then maintained for 5 hours, cooled to room temperature, ground again, and then calcined in the muffle furnace at a heating rate of 5°C / min until it reached 1000°C. The temperature was then maintained for 15 hours, cooled to room temperature, and then transferred to a storage box for later use. The obtained positive electrode material, conductive additive SP, and binder PVDF were mixed in weight ratios of 80 parts, 10 parts, and 10 parts, respectively, and dissolved in solvent NMP. A uniform slurry was obtained by stirring. The slurry was then uniformly coated onto carbon-coated aluminum foil using a 200μm scraper, dried, and sliced ​​to obtain the positive electrode sheet.

[0062] Comparative Example 2

[0063] (S1) Weigh 0.105 mmol sodium carbonate, 0.02475 mmol nickel-iron-manganese hydroxide precursor (NiFeMn(OH)2), and 0.012375 mmol ferric oxide and mix them to obtain mixture I;

[0064] (S2) Mixture I was placed in a magnetic boat and then placed in a muffle furnace for the first calcination. The heating rate was 5℃ / min. After reaching 450℃, the temperature was held for 5 hours and then cooled to room temperature to obtain the first calcination product. The first calcination product was ground and mixed with 0.00033 mmol cerium dioxide, 0.000165 mmol lanthanum oxide, and 0.000165 mmol yttrium trioxide.

[0065] (S3) The mixture is then placed in a muffle furnace for a second calcination at a heating rate of 5℃ / min. After reaching 1000℃, it is held for 15h and then cooled to room temperature to obtain the iron-based sodium oxide cathode material for sodium-ion batteries.

[0066] (S4) The obtained positive electrode material, conductive additive SP, and binder PVDF are mixed in 80 parts, 10 parts, and 10 parts by weight, respectively, and dissolved in solvent NMP. After stirring, a uniform slurry is obtained. The slurry is then uniformly coated on carbon-coated aluminum foil using a 200μm scraper, dried, and sliced ​​to obtain the positive electrode sheet.

[0067] Compared to Example 1, yttrium trioxide source A was added together with sources B and C after the first calcination.

[0068] Application examples Testing of electrochemical performance

[0069] Electrochemical performance testing: Coin cells were assembled using the electrodes obtained in Examples 1-8 and Comparative Example 1 as positive electrodes, sodium metal sheets as negative electrodes, glass fiber as separators, and 1 mol / L NaClO4 (PC + 5% FEC) as the electrolyte. The positive electrode was activated for one cycle at a current density of 13 mA / g within the voltage range of 2.0–4.0 V, followed by two cycles at a current density of 26 mA / g, and then charge-discharge cycles at a current density of 130 mA / g. The electrochemical performance of the sodium batteries in the examples and comparative examples of this invention was tested, and the results are shown in Table 1.

[0070] Table 1 Electrochemical performance data

[0071]

[0072] The capacity retention rate after 200 laps** is relative to the 4th lap; the first three laps are part of the formation process.

[0073] from Figure 1 It can be seen that the material after high-entropy modification of the interface still retains the structure of the O3 phase and can be classified as the R3m type space group. From Figure 2 The SEM images show that the cathode material particles after high-entropy modification are smaller, have smoother surfaces, and are more rounded. This may be because heavy elements are adsorbed on the surface of the particles during the calcination process, thus affecting the particle growth process.

[0074] As can be seen from the test results of the half-cells in Table 1 for each embodiment, the capacity retention of sodium-ion batteries after 200 cycles is significantly improved after constructing an interfacial high-entropy layer on the surface of the layered cathode material. For example, in Example 1, the capacity retention is still 91.3% after 200 cycles, while in Comparative Example 1, it is only 61% of the reversible specific capacity. This is because surface high-entropy doping leads to the formation of a spinel phase on the surface, suppressing surface degradation during cycling. Furthermore, the presence of the surface high-entropy structure results in a lower Gibbs free energy, making the structure more stable and thus improving cycle stability. It is worth noting that the element doping content needs to be appropriate. Excessive element content may lead to the formation of inactive impurity phases due to the influence of solid solubility, which could degrade performance. In addition, when the calcination time is long, the diffusion of elements is more uniform, which may result in a uniform distribution of the doped heavy element bulk phase instead of forming an interfacial high-entropy layer.

[0075] This invention provides a modification design concept and preparation method for a high-entropy layered oxide sodium-ion battery cathode. By constructing a high-entropy interfacial layer, the structural stability of the interface is enhanced, and the structural degradation of the layered phase at the interface during cycling is avoided, which can significantly improve the cycle stability of sodium-ion batteries. Furthermore, the synthesis process is simple and efficient, suitable for large-scale industrial production. It is understood that although the invention has been described in detail in various embodiments with specific electrolytes, separators, current collectors, active materials, binders, conductive additives, etc., this is merely to meet legal requirements and illustrate the composition of sodium-ion batteries, and the invention is not limited to the given embodiments. Any modifications, equivalent substitutions, and improvements made using this invention's specification within the spirit and principles of this invention, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this invention.

Claims

1. A layered oxide cathode material for sodium-ion batteries with high interfacial entropy, characterized in that, The chemical formula is expressed as NaNi x Fe y Mn z A a B b C c D d O2, where x + y + z + a + b + c + d = 1, a + b + c + d ≤ 0.1, and a > 0, b > 0, c > 0, d > 0, where A is at least one of Y, Zr, and Nb, B is at least one of a lanthanide element or Ta and W, and C and D are at least one of the transition metal elements in the fourth and fifth periods; The method for preparing the high-entropy layered oxide sodium-ion battery cathode material is characterized by comprising the following steps: (S1) Add sodium source, nickel source, iron source, manganese source and element A source, mix them evenly to obtain mixture I; (S2) Mixture I was calcined for the first time at 400-600℃. After cooling, element B and C sources were added and mixed evenly to obtain mixture II. After cooling, in addition to element B and C sources, element D source was also added. (S3) Mixture II was calcined a second time at 800-1200℃ and cooled to obtain a layered oxide sodium-ion battery cathode material with high interfacial entropy.

2. The high-entropy layered oxide sodium-ion battery cathode material according to claim 1, characterized in that, 0.01≤a+b+c+d≤0.

05.

3. The high-entropy layered oxide sodium-ion battery cathode material according to claim 1, characterized in that, A, B, C, and D satisfy the condition that a:b:c:d = 1-2:1-2:1-2:1-2.

4. The high-entropy layered oxide sodium-ion battery cathode material according to claim 3, characterized in that, Then A, B, C, and D satisfy a:b:c:d=1-1.3:1-1.3:1-1.3:1-1.

3.

5. The high-entropy layered oxide sodium-ion battery cathode material according to claim 1, characterized in that, The sodium source is selected from at least one of sodium carbonate, sodium bicarbonate, sodium acetate, sodium oxalate, sodium hydroxide, sodium oxide, sodium peroxide, and sodium nitrite; the nickel, iron, and manganese source materials are selected from at least one of oxides, hydroxides, sulfates, nitrates, carbonates, acetates, oxalates, and their hydrated compounds of nickel, iron, and manganese.

6. The high-entropy layered oxide sodium-ion battery cathode material according to claim 1, characterized in that, The dopant source A, source B, source C, and source D are selected from at least one of the oxides, hydroxides, sulfates, nitrates, carbonates, acetates, oxalates, and their hydrated compounds of the dopant element.

7. The high-entropy layered oxide sodium-ion battery cathode material according to claim 1, characterized in that, The sodium source material is fed in according to the stoichiometric ratio determined by the general structural formula, while the sodium source material is fed in at 100%-120% of the stoichiometric ratio, and the mixture is stirred evenly to form a mixture.

8. The high-entropy layered oxide sodium-ion battery cathode material according to claim 1, characterized in that, The purity of the raw materials is greater than 99%.

9. The high-entropy layered oxide sodium-ion battery cathode material according to claim 1, characterized in that, The purity of the raw materials is greater than or equal to 99.9%.

10. The high-entropy layered oxide sodium-ion battery cathode material according to claim 1, characterized in that, Mixing methods include manual mixing or mechanical mixing.

11. The high-entropy layered oxide sodium-ion battery cathode material according to claim 10, characterized in that, The mixing method is selected from at least one of mechanical ball milling, manual grinding, and mechanical grinding; wherein the ball milling mixing time is 1-50 hours, the ball mill speed is 200-1000 rpm, the manual grinding time is 10-60 minutes, and the mechanical grinding time is 10-60 minutes.

12. The high-entropy layered oxide sodium-ion battery cathode material according to claim 1, characterized in that, The calcination atmosphere is at least one of oxygen, air, nitrogen, and argon. The primary calcination temperature is 300-600℃, the holding time is 1-10h, the heating rate is 1-10℃ / min, and the cooling rate is 1-10℃ / min, or the furnace is cooled. The secondary calcination temperature is 800-1200℃, the holding time is 5-40h, the heating rate is 1-10℃ / min, and the cooling rate is 1-10℃ / min, or the furnace is cooled.

13. A sodium-ion battery, characterized in that, The positive electrode includes the layered oxide sodium-ion battery positive electrode material with high interfacial entropy as described in any one of claims 1-12.

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