A sodium manganate composite cathode material and its preparation method

Abstract

The present invention discloses a sodium manganate composite cathode material, which is prepared by the following method: depositing a Na<subgt;1.0< / subgt;Mn<subgt;0.7< / subgt;Fe<subgt;0.1< / subgt;Cu<subgt;0.1< / subgt;Nd<subgt;0.1< / subgt;O<subgt;2< / subgt> layer on a substrate by magnetron sputtering; depositing a Na<subgt;1.0< / subgt;Mn<subgt;0.7< / subgt;Fe<subgt;0.05< / subgt;Cu<subgt;0.05< / subgt>Nd<subgt;0.2< / subgt>O<subgt;2 layer on the Na<subgt;1.0< / subgt;Mn<subgt;0.7< / subgt;Fe<subgt;0.1< / subgt;Cu<subgt;0.1< / subgt;Nd<subgt;0.1< / subgt>O<subgt;2 layer by magnetron sputtering; depositing a Na<subgt;1.0< / subgt;Mn<subgt;0.7< / subgt;Fe<subgt;0.1< / subgt>Ti<subgt;0.1< / subgt>Ce<subgt;0.1< / subgt>O<subgt;2 layer on the Na<subgt;1.0< / subgt;Mn<subgt;0.7< / subgt;Fe<subgt;0.05< / subgt;Cu<subgt;0.05< / subgt>Nd<subgt;0.2< / subgt>O<subgt;2 layer by magnetron sputtering; depositing a Na<subgt;1.0< / subgt;Mn<subgt;0.7< / subgt;Fe<subgt;0.1< / subgt>Al<subgt;0.1< / subgt>Gd<subgt;0.1< / subgt>O<subgt;2 layer on the Na<subgt;1.0< / subgt;Mn<subgt;0.7< / subgt;Fe<subgt;0.1< / subgt>Ti<subgt;0.1< / subgt>Ce<subgt;0.1< / subgt>O<subgt;2 layer by magnetron sputtering; depositing a Na<subgt;1.0< / subgt;Mn<subgt;0.7< / subgt;Fe<subgt;0.1< / subgt>Al<subgt;0.Deposit a Na1.0Mn0.7Fe0.05Al0.05Gd0.2O2 layer on the 1 Gd0.1O2 layer; peel the composite film from the substrate to obtain a sodium manganate composite cathode material.

Description

Technical Field

[0001] The present invention relates to the technical field of sodium-ion batteries, and particularly to a sodium manganate composite cathode material and a preparation method thereof. Background Art

[0002] Due to the scarcity of lithium elements, there is currently a call in the industry to use sodium-ion batteries to replace lithium-ion batteries. Compared with lithium-ion batteries, sodium resources are abundant and widely distributed on the earth, and the mining cost is low, making sodium-ion batteries have great cost advantages in large-scale energy storage applications. With the continuous increase in the utilization of renewable energy, the demand for low-cost and high-efficiency energy storage technologies is becoming more urgent. Sodium-ion batteries have become a research hotspot and are of great significance for solving the storage problem of renewable energy. The sodium manganate composite cathode material is a key component of sodium-ion batteries, and its research is of great significance for promoting the development of sodium-ion batteries.

[0003] The prior art CN117878307A (hereinafter referred to as Document 1) proposes a sodium manganate cathode material, a preparation method thereof and an application. The main design idea of Document 1 is to use a variety of transition metal elements to replace the manganese element in traditional sodium manganate, so as to improve the performance of the sodium-ion battery cathode material. The main defects of Document 1 are as follows: 1. Since Document 1 uses the traditional powder metallurgy method to prepare the battery cathode material, the cathode material has a single composition, and there is only one component in the cathode material of a battery, and the advantages of the composite material cannot be exerted; 2. Since Document 1 uses the traditional powder metallurgy method to prepare the battery cathode material, Document 1 cannot form nanocrystals. After verification by the present invention, within a certain range, the larger the grain size, the worse the performance of the cathode material; 3. Document 1 does not consider the special f-layer electrons of rare earth elements to improve the performance of the cathode material. Summary of the Invention

[0004] To achieve the above object, the present invention provides a sodium manganate composite cathode material, which is prepared by the following method:

[0005] Deposit Na 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 O2 layer on the substrate by magnetron sputtering;

[0006] Deposit Na 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 O2 layer by magnetron sputtering on the Na 1.0 Mn 0.7 Fe 0.05 Cu0.05 Nd 0.2 O₂ layer;

[0007] Deposit Na on the 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 O₂ layer by magnetron sputtering; 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 O₂ layer;

[0008] Deposit Na on the 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 O₂ layer by magnetron sputtering; 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 O₂ layer;

[0009] Deposit Na on the 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 O₂ layer by magnetron sputtering; 1.0 Mn 0.7 Fe 0.05 Al 0.05 Gd 0.2 O₂ layer;

[0010] Peel the composite film from the substrate to obtain the sodium manganate composite cathode material.

[0011] In a preferred embodiment, the thickness of the 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 O₂ layer is 100 - 200 nm, and the thickness of the 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 O₂ layer is 50 - 100 nm, and the thickness of the 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 O₂ layer is 100 - 200 nm, and the thickness of the 1.0 Mn 0.7Fe 0.1 Al 0.1 Gd 0.1 The thickness of the O2 layer is 50 - 100 nm, Na 1.0 Mn 0.7 Fe 0.05 Al 0.05 Gd 0.2 The thickness of the O2 layer is 100 - 200 nm.

[0012] In a preferred embodiment, Na is deposited on the substrate by magnetron sputtering 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 Specifically, for the O2 layer: the magnetron sputtering power supply is a radio frequency power supply, the sputtering atmosphere is an argon atmosphere, the argon flow rate is 30 - 50 sccm, the sputtering power is 100 - 150 W, the sputtering voltage is 100 - 150 V, and the sputtering temperature is 100 - 150 °C.

[0013] In a preferred embodiment, Na is deposited on the Na 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 O2 layer by magnetron sputtering 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 Specifically, for the O2 layer: the magnetron sputtering power supply is a radio frequency power supply, the sputtering atmosphere is an argon atmosphere, the argon flow rate is 30 - 50 sccm, the sputtering power is 200 - 300 W, the sputtering voltage is 100 - 150 V, and the sputtering temperature is 100 - 150 °C.

[0014] In a preferred embodiment, Na is deposited on the Na 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 O2 layer by magnetron sputtering 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 Specifically, for the O2 layer: the magnetron sputtering power supply is a radio frequency power supply, the sputtering atmosphere is an argon atmosphere, the argon flow rate is 30 - 50 sccm, the sputtering power is 100 - 150 W, the sputtering voltage is 50 - 100 V, and the sputtering temperature is 100 - 150 °C.

[0015] In a preferred embodiment, Na is deposited on the Na 1.0 Mn0.7 Fe 0.1 Ti 0.1 Ce 0.1 Deposit Na on the O2 layer 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 The O2 layer specifically is: The magnetron sputtering power supply is a radio frequency power supply, the sputtering atmosphere is an argon atmosphere, the argon flow rate is 30 - 50 sccm, the sputtering power is 100 - 150 W, the sputtering voltage is 50 - 100 V, and the sputtering temperature is 100 - 150 °C.

[0016] In a preferred embodiment, use magnetron sputtering to deposit Na on the 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 O2 layer 1.0 Mn 0.7 Fe 0.05 Al 0.05 Gd 0.2 The O2 layer specifically is: The magnetron sputtering power supply is a radio frequency power supply, the sputtering atmosphere is an argon atmosphere, the argon flow rate is 30 - 50 sccm, the sputtering power is 200 - 250 W, the sputtering voltage is 100 - 150 V, and the sputtering temperature is 100 - 150 °C.

[0017] The present invention provides a preparation method of a sodium manganate composite cathode material, and the preparation method includes:

[0018] Use magnetron sputtering to deposit a Na 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 O2 layer;

[0019] Use magnetron sputtering to deposit Na on the 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 O2 layer 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 O2 layer;

[0020] Use magnetron sputtering to deposit Na on the 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 O2 layer1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 O₂ layer;

[0021] Deposit Na on the 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 O₂ layer by magnetron sputtering 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 O₂ layer;

[0022] Deposit Na on the 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 O₂ layer by magnetron sputtering 1.0 Mn 0.7 Fe 0.05 Al 0.05 Gd 0.2 O₂ layer;

[0023] Peel the composite film from the substrate to obtain the sodium manganate composite cathode material.

[0024] In a preferred embodiment, the thickness of the 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 O₂ layer is 100 - 200 nm, and the thickness of the 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 O₂ layer is 50 - 100 nm. The thickness of the 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 O₂ layer is 100 - 200 nm, and the thickness of the 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 O₂ layer is 50 - 100 nm. The thickness of the 1.0 Mn 0.7 Fe 0.05 Al 0.05 Gd 0.2The thickness of the O2 layer is 100 - 200 nm.

[0025] Compared with the prior art, the present invention has the following advantages: The prior art uses the traditional powder metallurgy method in the preparation of the positive electrode material. Therefore, the positive electrode material of the prior art has a single composition, cannot give full play to the advantages of the composite material, and cannot form nanocrystals. In addition, the prior art does not consider the improvement of the performance of the positive electrode material by the special f-layer electrons of rare earth elements. Aiming at the defects of the prior art, through the method proposed by the present invention, the present invention can obtain a composite positive electrode material with rich components, and a large number of nanocrystals are included inside the composite positive electrode material of the present invention. Moreover, rare earth elements are added to the composite positive electrode material of the present invention. Through the cooperation of different types and contents of rare earth elements and transition elements, the composite positive electrode material of the present invention can improve the battery performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic structural diagram of an embodiment of the present invention.

[0027] Figure 2 It is a flowchart of the method of an embodiment of the present invention.

[0028] Figure 3 It is an HRTEM photograph of an embodiment of the present invention for verifying the ability to form nanocrystals.

[0029] Figure 4 It is an HRTEM photograph of an embodiment of the present invention for verifying the ability to form nanocrystals. DETAILED DESCRIPTION OF THE INVENTION

[0030] The following will describe in detail the specific embodiments of the present invention with reference to the drawings, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

[0031] Figure 1 It is a schematic structural diagram of an embodiment of the present invention. As shown in the figure, the composite film layer prepared by using the preparation method proposed by the present invention sequentially includes: a substrate, Na 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 O2 layer, Na 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 O2 layer, Na 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 O2 layer, Na 1.0 Mn 0.7Fe 0.1 Al 0.1 Gd 0.1 O2 layer and Na 1.0 Mn 0.7 Fe 0.05 Al 0.05 Gd 0.2 O2 layer. Among them, the composite film referred to throughout the present invention includes Na 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 O2 layer, Na 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 O2 layer, Na 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 O2 layer, Na 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 O2 layer and Na 1.0 Mn 0.7 Fe 0.05 Al 0.05 Gd 0.2 Composite film of O2 layer. The substrate can be a silicon, alumina, or glass substrate.

[0032] Figure 2 is a flowchart of the method of an embodiment of the present invention. As shown in the figure, the preparation method of the present invention includes the following steps:

[0033] Step 1: Deposit Na 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 O2 layer on the substrate; It can be understood that the target for depositing Na 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 O2 layer is a Na 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 O2 target, Na 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd0.1 The manufacturing method of the O2 target can refer to the prior art CN117832474A (hereinafter referred to as Document 2). For the purpose of full disclosure, the full text of the prior art Document 2 is incorporated herein. For clarity purposes, part of the content of Document 2 is cited here to briefly introduce Na 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 The preparation process of the O2 target. The sodium source is selected as sodium sulfate, the manganese source is selected as manganese carbonate, the iron source is selected as iron nitrate, the copper source is selected as copper sulfate, and the Nd source is selected as NdCl2 (the existence of NdCl2 can be proved by the US patent document US7048809B2, and this substance can be purchased from a chemical store). Weigh the corresponding amounts of sodium sulfate, manganese carbonate, iron nitrate, copper sulfate, the selected Nd source and NdCl2 according to the molar ratio of each element designed, then mix the raw materials with citric acid to obtain a precursor. Subsequently, put the precursor into a mold, and place the mold with the precursor into a heat treatment furnace for sintering. The sintering atmosphere is an air atmosphere, the sintering temperature is 800 degrees Celsius, and the sintering time is 15h to obtain Na 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 O2 target.

[0034] Step 2: Deposit a Na 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 O2 layer on the Na 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 O2 layer; The deposited Na 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 O2 layer uses the Na 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 O2 target, and the preparation method of the Na 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 O2 target is the same as the target manufacturing method described in Step 1, with the only difference being the ratio of each raw material.

[0035] Step 3: Use magnetron sputtering to deposit on the Na1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 Deposit Na on the O2 layer 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 O2 layer; deposit Na 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 Use Na in the O2 layer 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 O2 target, Na 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 The preparation method of the O2 target is the same as the target manufacturing method described in Step 1, except for the ratio of each raw material. The Ce source is selected as CeCl2 (the existence of CeCl2 can be proved by the US patent document US8052889B2).

[0036] Step 4: Use magnetron sputtering to deposit Na on the 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 O2 layer 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 O2 layer; deposit Na 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 Use Na in the O2 layer 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 O2 target, Na 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 The preparation method of the O2 target is the same as the target manufacturing method described in Step 1, except for the ratio of each raw material. The Gd source is selected as GdCl2.

[0037] Step 5: Use magnetron sputtering to deposit Na on the1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 Deposit Na on the O2 layer 1.0 Mn 0.7 Fe 0.05 Al 0.05 Gd 0.2 O2 layer; deposit Na 1.0 Mn 0.7 Fe 0.05 Al 0.05 Gd 0.2 Use Na in the O2 layer 1.0 Mn 0.7 Fe 0.05 Al 0.05 Gd 0.2 O2 target, Na 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 O2Na 1.0 Mn 0.7 Fe 0.05 Al 0.05 Gd 0.2 The preparation method of the O2 target is the same as the target manufacturing method introduced in Step 1, except for the ratio of each raw material. The Gd source is selected as GdCl2.

[0038] Step 6: Peel the composite film from the substrate to obtain the sodium manganate composite cathode material. The composite film can be peeled from the substrate by mechanical peeling.

[0039] Example 1

[0040] Prepare the cathode material by the following method: Deposit Na on the substrate by magnetron sputtering 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 O2 layer; Deposit Na on Na by magnetron sputtering 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 Deposit Na on the O2 layer 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 O2 layer; Deposit Na on Na by magnetron sputtering 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd0.2 Deposit Na on the O2 layer 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 O2 layer; deposit Na on the 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 Deposit Na on the O2 layer 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 O2 layer; deposit Na on the 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 Deposit Na on the O2 layer 1.0 Mn 0.7 Fe 0.05 Al 0.05 Gd 0.2 O2 layer; peel the composite film from the substrate to obtain the sodium manganate composite cathode material.

[0041] Na 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 The thickness of the O2 layer is 100 nm, Na 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 The thickness of the O2 layer is 50 nm, Na 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 The thickness of the O2 layer is 100 nm, Na 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 The thickness of the O2 layer is 50 nm, Na 1.0 Mn 0.7 Fe 0.05 Al 0.05 Gd 0.2 The thickness of the O2 layer is 100 nm.

[0042] Deposit Na on the substrate by magnetron sputtering 1.0 Mn 0.7 Fe 0.1Cu 0.1 Nd 0.1 The O2 layer is specifically as follows: The magnetron sputtering power supply is a radio frequency power supply, the sputtering atmosphere is an argon atmosphere, the argon flow rate is 30 sccm, the sputtering power is 100 W, the sputtering voltage is 100 V, and the sputtering temperature is 100 °C.

[0043] Deposit Na on the O2 layer by magnetron sputtering 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 Deposit Na on the O2 layer 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 The O2 layer is specifically as follows: The magnetron sputtering power supply is a radio frequency power supply, the sputtering atmosphere is an argon atmosphere, the argon flow rate is 30 sccm, the sputtering power is 200 W, the sputtering voltage is 100 V, and the sputtering temperature is 100 °C.

[0044] Deposit Na on the O2 layer by magnetron sputtering 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 Deposit Na on the O2 layer 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 The O2 layer is specifically as follows: The magnetron sputtering power supply is a radio frequency power supply, the sputtering atmosphere is an argon atmosphere, the argon flow rate is 30 sccm, the sputtering power is 100 W, the sputtering voltage is 50 V, and the sputtering temperature is 100 °C.

[0045] Deposit Na on the O2 layer by magnetron sputtering 1.0 Mn 0.7 Fe 0.1 Ti 0.1 )]]Ce 0.1 Deposit Na on the O2 layer 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 The O2 layer is specifically as follows: The magnetron sputtering power supply is a radio frequency power supply, the sputtering atmosphere is an argon atmosphere, the argon flow rate is 30 sccm, the sputtering power is 100 W, the sputtering voltage is 50 V, and the sputtering temperature is 100 °C.

[0046] Deposit Na on the O2 layer by magnetron sputtering 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 Deposit Na on the O2 layer1.0 Mn 0.7 Fe 0.05 Al 0.05 Gd 0.2 The O2 layer is specifically as follows: the magnetron sputtering power supply is a radio frequency power supply, the sputtering atmosphere is an argon atmosphere, the argon flow rate is 30 sccm, the sputtering power is 200 W, the sputtering voltage is 100 V, and the sputtering temperature is 100 ° C. The composite positive electrode material obtained in Example 1 is used to assemble the battery. In order to ensure the comparability of the experimental results, the method of assembling the battery is based on Reference 1. For the purpose of clarity, the content of Reference 1 is partially quoted here to illustrate the method of assembling the battery. In the positive electrode sheet, the mass ratio of the composite positive electrode material, conductive agent, and binder of Example 1 is 96:1.5:2.5. The conductive agent is acetylene black, the binder is polyvinyl fluoride, and the solvent is N-methylpyrrolidone. The prepared positive electrode sheet, negative electrode sheet, electrolyte, and diaphragm are assembled into a CR2032 button battery in a glove box filled with argon. The negative electrode sheet is a sodium metal sheet, the electrolyte solvent is composed of dimethyl carbonate, diethyl carbonate, and ethyl carbonate in a volume ratio of 1:1:1, the solute of the electrolyte is 0.25M NaPF6, and the separator model is Celgard 3000. Test items include first-cycle coulombic efficiency, 1C gram capacity, and 100-cycle cycle retention rate. The battery assembled based on the composite positive electrode material of Example 1 has a first-cycle coulombic efficiency of 99.5%, a 1C gram capacity of 142.5mAh / g, and a 100-cycle cycle retention rate of 97%. The electrical performance of the battery assembled based on the composite positive electrode material of Example 1 has a significant increase compared to the prior art. The reasons for the increase can be attributed to the following: 1. Since the present invention prepares the composite positive electrode material by magnetron sputtering, the composite positive electrode material of the present invention is rich in components, and the layers of each component cooperate with each other, which improves the electron transport performance, thereby improving the battery performance; 2. Rare earth elements are added to the composite positive electrode material of the present invention. Rare earth elements have special f-layer electrons. The f-layer electrons interact with the d-layer electrons of the transition metal, which may form a special energy band structure, thereby helping to improve the electron transport performance; 3. A large number of nanocrystals are formed in the composite positive electrode material of the present invention, which also helps to improve the performance of the positive electrode material. In order to verify the formation of nanocrystals in the composite positive electrode material, the present invention provides Figure 3 and Figure 4 HRTEM images of Figure 3 It is in Na 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 Na is deposited on the O2 layer 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2After the O2 layer, the sample with the substrate is directly mechanically cut (but the film layer is not peeled off), and then ion thinning is carried out to obtain a specimen for TEM testing (the entire TEM experiment is entrusted to the Materials Science Laboratory of Zhengzhou University). It should be understood that unless heat treatment at a higher temperature is carried out, subsequent film sputtering will not cause Na 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 The lattice size of the O2 layer increases. Therefore, Figure 3 Although the sample in Figure 3 did not perform subsequent sputtering, but 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 The grains of the O2 layer are nanocrystals. As Figure 3 shown, at the orientation of the electron beam and the sample in Figure 3 , three grains can be clearly observed, and the sizes of these grains are all less than 5 nm. Figure 4 is on the Na 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 O2 layer, after depositing Na 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 O2 layer, the sample with the substrate is directly mechanically cut (but the film layer is not peeled off), and then ion thinning is carried out to obtain a specimen for TEM testing. At the orientation of the electron beam and the sample in Figure 4 , a grain can be clearly observed. The direction with a larger size of the grain has been indicated by the white line in the figure. It can be seen that the size of the grain is about 4 nm.

[0047] Example 2

[0048] The cathode material is prepared by the following method: Na 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 O2 layer is deposited on the substrate by magnetron sputtering; Na 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 O2 layer is deposited on the Na 1.0 Mn 0.7 Fe0.05 Cu 0.05 Nd 0.2 O2 layer; using magnetron sputtering on Na 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 Na is deposited on the O2 layer 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 O2 layer; using magnetron sputtering on Na 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 Na is deposited on the O2 layer 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 O2 layer; using magnetron sputtering on Na 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 Na is deposited on the O2 layer 1.0 Mn 0.7 Fe 0.05 Al 0.05 Gd 0.2 O2 layer; peeling the composite film from the substrate to obtain a sodium manganate composite positive electrode material.

[0049] Na 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 The thickness of the O2 layer is 200nm, and the Na 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 The thickness of the O2 layer is 100 nm, and the Na 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 The thickness of the O2 layer is 200nm, and the Na 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 The thickness of the O2 layer is 100 nm, and the Na 1.0 Mn 0.7 Fe 0.05 Al0.05 Gd 0.2 The thickness of the O2 layer is 200 nm.

[0050] Deposition of Na on substrate by magnetron sputtering 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 The specific conditions for the O2 layer are: the magnetron sputtering power supply is a radio frequency power supply, the sputtering atmosphere is an argon atmosphere, the argon flow rate is 50 sccm, the sputtering power is 150 W, the sputtering voltage is 150 V, and the sputtering temperature is 150°C.

[0051] Magnetron sputtering was used to deposit Na 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 Na is deposited on the O2 layer 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 The specific conditions for the O2 layer are: the magnetron sputtering power supply is a radio frequency power supply, the sputtering atmosphere is an argon atmosphere, the argon flow rate is 50 sccm, the sputtering power is 300 W, the sputtering voltage is 150 V, and the sputtering temperature is 150°C.

[0052] Magnetron sputtering was used to deposit Na 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 Na is deposited on the O2 layer 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 The specific conditions for the O2 layer are: the magnetron sputtering power supply is a radio frequency power supply, the sputtering atmosphere is an argon atmosphere, the argon flow rate is 50 sccm, the sputtering power is 150 W, the sputtering voltage is 100 V, and the sputtering temperature is 150°C.

[0053] Magnetron sputtering was used to deposit Na 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 Na is deposited on the O2 layer 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1The specific conditions for the O2 layer are: the magnetron sputtering power supply is a radio frequency power supply, the sputtering atmosphere is an argon atmosphere, the argon flow rate is 50 sccm, the sputtering power is 150 W, the sputtering voltage is 100 V, and the sputtering temperature is 150°C.

[0054] Magnetron sputtering was used to deposit Na 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 Na is deposited on the O2 layer 1.0 Mn 0.7 Fe 0.05 Al 0.05 Gd 0.2 The O2 layer is specifically as follows: the magnetron sputtering power supply is a radio frequency power supply, the sputtering atmosphere is an argon atmosphere, the argon flow rate is 50 sccm, the sputtering power is 250 W, the sputtering voltage is 150 V, and the sputtering temperature is 150°C. The method of assembling the battery is the same as that of Example 1 and will not be repeated here. The battery assembled based on the composite positive electrode material of Example 2 has a first-cycle coulombic efficiency of 99.3%, a 1C gram capacity of 145.4 mAh / g, and a 100-cycle cycle retention rate of 96.8%.

[0055] Example 3

[0056] The cathode material was prepared by the following method: Na was deposited on the substrate by magnetron sputtering. 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 O2 layer; using magnetron sputtering on Na 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 Na is deposited on the O2 layer 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 O2 layer; using magnetron sputtering on Na 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 Na is deposited on the O2 layer 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 O2 layer; using magnetron sputtering on Na 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 Na is deposited on the O2 layer1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 O2 layer; deposit Na by magnetron sputtering on Na 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 O2 layer and deposit Na on it 1.0 Mn 0.7 Fe 0.05 Al 0.05 Gd 0.2 O2 layer; peel the composite film from the substrate to obtain the sodium manganate composite cathode material.

[0057] Na 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 The thickness of the O2 layer is 150 nm, and Na 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 The thickness of the O2 layer is 70 nm, and Na 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 The thickness of the O2 layer is 150 nm, and Na 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 The thickness of the O2 layer is 70 nm, and Na 1.0 Mn 0.7 Fe 0.05 Al 0.05 Gd 0.2 The thickness of the O2 layer is 150 nm.

[0058] Deposit Na on the substrate by magnetron sputtering 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 The O2 layer specifically is: the magnetron sputtering power supply is a radio frequency power supply, the sputtering atmosphere is an argon atmosphere, the argon flow rate is 50 sccm, the sputtering power is 120 W, the sputtering voltage is 120 V, and the sputtering temperature is 120 °C.

[0059] Deposit by magnetron sputtering on Na 1.0 Mn 0.7 Fe 0.1 Cu0.1 Nd 0.1 Deposit Na on the O2 layer 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 The O2 layer specifically is: The magnetron sputtering power supply is a radio frequency power supply, the sputtering atmosphere is an argon atmosphere, the argon flow rate is 50 sccm, the sputtering power is 250 W, the sputtering voltage is 120 V, and the sputtering temperature is 120 °C.

[0060] Deposit Na on the O2 layer by magnetron sputtering 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 Deposit Na on the O2 layer 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 The O2 layer specifically is: The magnetron sputtering power supply is a radio frequency power supply, the sputtering atmosphere is an argon atmosphere, the argon flow rate is 50 sccm, the sputtering power is 120 W, the sputtering voltage is 70 V, and the sputtering temperature is 120 °C.

[0061] Deposit Na on the O2 layer by magnetron sputtering 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 Deposit Na on the O2 layer 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 The O2 layer specifically is: The magnetron sputtering power supply is a radio frequency power supply, the sputtering atmosphere is an argon atmosphere, the argon flow rate is 50 sccm, the sputtering power is 120 W, the sputtering voltage is 70 V, and the sputtering temperature is 120 °C.

[0062] Deposit Na on the O2 layer by magnetron sputtering 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 Deposit Na on the O2 layer 1.0 Mn 0.7 Fe 0.05 Al 0.05 Gd 0.2The O2 layer specifically is as follows: The magnetron sputtering power supply is a radio frequency power supply, the sputtering atmosphere is an argon atmosphere, the argon flow rate is 50 sccm, the sputtering power is 220 W, the sputtering voltage is 120 V, and the sputtering temperature is 120 °C. The method of assembling the battery is the same as that in Example 1 and will not be elaborated here. The first-cycle Coulombic efficiency of the battery assembled with the composite cathode material based on Example 3 is 99.4%, the 1C specific capacity is 144.3 mAh / g, and the 100-cycle retention rate is 97.2%.

[0063] Comparative Example 1

[0064] The cathode material is prepared by the following method: Depositing Na 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 O2 layer on a substrate by magnetron sputtering; Depositing Na 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 O2 layer on the Na 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 O2 layer by magnetron sputtering; Depositing Na 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 O2 layer on the Na 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 O2 layer by magnetron sputtering; Depositing Na 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 O2 layer on the Na 1.0 Mn 0.7 Fe 0.05 Al 0.05 Gd 0.2Oxygen layer 2; The composite film was peeled off from the substrate to obtain the sodium manganate composite cathode material. The remaining process parameters were the same as those in Example 1 and will not be elaborated here. The method for assembling the battery was the same as that in Example 1 and will not be elaborated here. The first-cycle Coulombic efficiency of the battery assembled with the composite cathode material of Comparative Example 1 was 93.4%, the 1C specific capacity was 129.3 mAh / g, and the 100-cycle retention rate was 92.2%. From the comparison between Comparative Example 1 and Examples 1-3, it can be seen that omitting certain film layer structures will lead to a significant decline in battery performance. The reason for this phenomenon may be that: the various film layers cooperate with each other. If some film layers are omitted, it may cause an increase in stress between the remaining film layers and an increase in lattice distortion, which will obviously and adversely affect the electron transport characteristics. In addition, omitting a certain film layer may lead to the failure of the cooperation between the f electrons of various rare earth elements and the d electrons of transition metals.

[0065] Comparative Example 2

[0066] The cathode material was prepared by the following method: Na was deposited on the substrate by magnetron sputtering 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 Oxygen layer 2; Na was deposited on the Na 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 Oxygen layer 2 by magnetron sputtering 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 Oxygen layer 2; Na was deposited on the Na 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 Oxygen layer 2 by magnetron sputtering 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 Oxygen layer 2; Na was deposited on the Na 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 Oxygen layer 2 by magnetron sputtering 1.0 Mn 0.7 Fe 0.05 Al 0.05 Gd 0.2The composite film is peeled off from the substrate to obtain a sodium manganate composite positive electrode material. The remaining process parameters are the same as those in Example 1 and are not further described. The battery assembly method is the same as in Example 1 and is not further described. The battery assembled based on the composite positive electrode material of Comparative Example 2 has an initial coulombic efficiency of 94.4%, a 1C gram capacity of 126.3 mAh / g, and a 100-cycle cycle retention rate of 93.2%. The explanation for the performance degradation in Comparative Example 2 is the same as that in Comparative Example 1.

[0067] Comparative Example 3

[0068] The cathode material was prepared by the following method: Na was deposited on the substrate by magnetron sputtering. 1.0 Mn 0.7 Fe 0.1 Cu 0.05 Nd 0.2 O2 layer; using magnetron sputtering on Na 1.0 Mn 0.7 Fe 0.1 Cu 0.05 Nd 0.2 Na is deposited on the O2 layer 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 O2 layer; using magnetron sputtering on Na 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 Na is deposited on the O2 layer 1.0 Mn 0.7 Fe 0.05 Ti 0.05 Ce 0.2 O2 layer; using magnetron sputtering on Na 1.0 Mn 0.7 Fe 0.05 Ti 0.05 Ce 0.2 Na is deposited on the O2 layer 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 O2 layer; using magnetron sputtering on Na 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 Na is deposited on the O2 layer 1.0 Mn 0.7 Fe 0.05 Al 0.05 Gd 0.2O2 layer; the composite film is peeled off from the substrate to obtain a sodium manganate composite positive electrode material. The remaining process parameters are the same as those in Example 1 and will not be repeated here. The method of assembling the battery is the same as that in Example 1 and will not be repeated here. The first-cycle coulomb efficiency of the battery assembled based on the composite positive electrode material of Comparative Example 3 is 94.8%, the 1C gram capacity is 134.3mAh / g, and the 100-cycle cycle retention rate is 94.2%. The reason for the performance degradation of Comparative Example 3 is that the composition ratio is unreasonable, which may lead to the failure of the coordination between the f electrons of various rare earth elements and the d electrons of transition metals. It will also lead to increased stress between the various film layers, lattice distortion, and adverse effects on electron transport.

[0069] Comparative Example 4

[0070] The composite positive electrode material of Example 1 was first subjected to a heat treatment at 700 degrees Celsius for 10 hours, and the heat treatment atmosphere was argon. The composite positive electrode material after heat treatment was used to assemble a battery. The method of assembling the battery is the same as that of Example 1 and will not be repeated here. The first-cycle coulombic efficiency of the battery assembled based on the composite positive electrode material of Comparative Example 3 was 95.8%, the 1C gram capacity was 136.5mAh / g, and the 100-cycle cycle retention rate was 94.5%. The reason for the performance degradation of Comparative Example 4 is that the grain size becomes larger. It can be understood that after the nanocrystalline material is further heat-treated, the grain size will become larger. Comparative Example 4 heat-treated the composite positive electrode material of Example 1, so that the grain size of the composite positive electrode material of Comparative Example 4 is larger than that of Example 1. Obviously, the larger grain size adversely affects the battery performance.

[0071] Comparative Example 5

[0072] Na 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 The thickness of the O2 layer is 300nm, and the Na 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 The thickness of the O2 layer is 300nm, and the Na 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 The thickness of the O2 layer is 300nm, and the Na 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 The thickness of the O2 layer is 300nm, and the Na 1.0 Mn 0.7 Fe 0.05 Al 0.05Gd 0.2 The thickness of the O2 layer was 300 nm. The remaining process parameters were the same as those in Example 1 and are not described in detail here. The film obtained in Comparative Example 5 exhibited obvious cracks, indicating that numerous defects existed at the interface between the film layers. Since the film obtained in Comparative Example 5 was a substandard product, no electrical performance testing was performed.

[0073] Comparative Example 6

[0074] Magnetron sputtering was used to deposit Na 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 Na is deposited on the O2 layer 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 The O2 layer is specifically as follows: the magnetron sputtering power supply is a radio frequency power supply, the sputtering atmosphere is an argon atmosphere, the argon flow rate is 50 sccm, the sputtering power is 500W, the sputtering voltage is 400V, and the sputtering temperature is 120°C. The remaining process parameters are the same as those in Example 1 and will not be repeated here. The method of assembling the battery is the same as in Example 1 and will not be repeated here. The first cycle coulomb efficiency of the battery assembled based on the composite positive electrode material of Comparative Example 6 is 92.4%, the 1C gram capacity is 116.3mAh / g, and the 100-cycle cycle retention rate is 85.2%. The reason for the performance degradation of Comparative Example 6 is that. Due to the deterioration of process parameters, Na 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 The O2 layer itself may have a large number of microscopic defects, and the interface between this layer and its two adjacent layers may also have a large number of defects. In addition, the stress between the interfaces is large and the lattice distortion is large, which may cause the battery performance to deteriorate rapidly.

[0075] It should be understood that the above-described specific embodiments of the present invention are merely illustrative or illustrative of the principles of the present invention and do not constitute limitations of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present invention should be included within the scope of protection of the present invention. In addition, the appended claims are intended to cover all variations and modifications that fall within the scope and metes and bounds of the appended claims, or equivalents thereof.

Claims

1. A sodium manganate composite cathode material, characterized in that, The material is prepared by the following method: Deposit Na on a substrate by magnetron sputtering 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 O2 layer; Deposit Na 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 on the Na 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 O2 layer by magnetron sputtering; Deposit Na on the 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 O2 layer by magnetron sputtering, and then deposit Na 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 O2 layer; Deposit Na 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 on the Na 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 O2 layer by magnetron sputtering; Deposit Na 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 on the Na 1.0 Mn 0.7 Fe 0.05 Al 0.05 Gd 0.2 O2 layer by magnetron sputtering; The composite thin film is peeled off from the substrate to obtain the sodium manganese composite cathode material, The Na 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 The thickness of the Na 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 O2 layer is 100 - 200 nm, and the Na 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 O2 layer is 100 - 200 nm, and the Na 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 O2 layer is 50 - 100 nm, and the Na 1.0 Mn 0.7 Fe 0.05 Al 0.05 Gd 0.2 The thickness of the O2 layer is 100 - 200 nm, Deposit Na on the substrate by magnetron sputtering 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 The O2 layer specifically is: The magnetron sputtering power supply is a radio frequency power supply, the sputtering atmosphere is an argon atmosphere, the argon flow rate is 30 - 50 sccm, the sputtering power is 100 - 150 W, the sputtering voltage is 100 - 150 V, and the sputtering temperature is 100 - 150 °C. Deposit Na on the Na 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 O2 layer by means of magnetron sputtering. The specific conditions for depositing the Na 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 O2 layer are as follows: The magnetron sputtering power supply is a radio frequency power supply, the sputtering atmosphere is an argon atmosphere, the argon flow rate is 30 - 50 sccm, the sputtering power is 200 - 300 W, the sputtering voltage is 100 - 150 V, and the sputtering temperature is 100 - 150 °C. Deposit Na by magnetron sputtering on the 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 O2 layer. The Na 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 O2 layer specifically is as follows: The magnetron sputtering power supply is a radio frequency power supply, the sputtering atmosphere is an argon atmosphere, the argon flow rate is 30 - 50 sccm, the sputtering power is 100 - 150 W, the sputtering voltage is 50 - 100 V, and the sputtering temperature is 100 - 150 °C. Deposit Na on the Na 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 O2 layer by means of magnetron sputtering. The specific conditions for depositing the Na 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 O2 layer are as follows: The magnetron sputtering power supply is a radio frequency power supply, the sputtering atmosphere is an argon atmosphere, the argon flow rate is 30 - 50 sccm, the sputtering power is 100 - 150 W, the sputtering voltage is 50 - 100 V, and the sputtering temperature is 100 - 150 °C. Deposit Na on the Na 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 O2 layer by magnetron sputtering. The Na 1.0 Mn 0.7 Fe 0.05 Al 0.05 Gd 0.2 O2 layer specifically is as follows: The magnetron sputtering power supply is a radio frequency power supply, the sputtering atmosphere is an argon atmosphere, the argon flow rate is 30 - 50 sccm, the sputtering power is 200 - 250 W, the sputtering voltage is 100 - 150 V, and the sputtering temperature is 100 - 150 °C.

2. A preparation method of a sodium manganate composite cathode material, characterized in that, The preparation method includes: Deposit Na on the substrate by magnetron sputtering 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 O2 layer; Deposit Na 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 on the Na 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 O2 layer by magnetron sputtering; Deposit Na 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 on the Na 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 O2 layer by means of magnetron sputtering; Deposit Na on the 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 O2 layer by magnetron sputtering, and then deposit Na 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 O2 layer; Deposit Na 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 on the Na 1.0 Mn 0.7 Fe 0.05 Al 0.05 Gd 0.2 O2 layer by magnetron sputtering; The composite thin film is peeled off from the substrate to obtain the sodium manganese composite cathode material, Among them, the Na 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 O2 layer has a thickness of 100 - 200 nm, and the Na 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 O2 layer has a thickness of 50 - 100 nm, and the Na 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 O2 layer has a thickness of 100 - 200 nm, and the Na 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 O2 layer has a thickness of 50 - 100 nm, and the Na 1.0 Mn 0.7 Fe 0.05 Al 0.05 Gd 0.2 O2 layer has a thickness of 100 - 200 nm, Deposit Na on the substrate by magnetron sputtering 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 The O2 layer is specifically as follows: the magnetron sputtering power supply is a radio frequency power supply, the sputtering atmosphere is an argon atmosphere, the argon flow rate is 30 - 50 sccm, the sputtering power is 100 - 150 W, the sputtering voltage is 100 - 150 V, and the sputtering temperature is 100 - 150 °C. Deposit Na by magnetron sputtering on the 1.0 Mn 0.7 Fe 0.1 Cu 0.1 Nd 0.1 O2 layer. The specific conditions for depositing the Na 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 O2 layer are as follows: The magnetron sputtering power supply is a radio frequency power supply, the sputtering atmosphere is an argon atmosphere, the argon flow rate is 30 - 50 sccm, the sputtering power is 200 - 300 W, the sputtering voltage is 100 - 150 V, and the sputtering temperature is 100 - 150 °C. Deposit Na on the Na 1.0 Mn 0.7 Fe 0.05 Cu 0.05 Nd 0.2 O2 layer by magnetron sputtering. The Na 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 O2 layer specifically is: the magnetron sputtering power supply is a radio frequency power supply, the sputtering atmosphere is an argon atmosphere, the argon flow rate is 30 - 50 sccm, the sputtering power is 100 - 150 W, the sputtering voltage is 50 - 100 V, and the sputtering temperature is 100 - 150 °C. Deposit Na on the Na 1.0 Mn 0.7 Fe 0.1 Ti 0.1 Ce 0.1 O2 layer by magnetron sputtering. The Na 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 O2 layer is specifically: the magnetron sputtering power supply is a radio frequency power supply, the sputtering atmosphere is an argon atmosphere, the argon flow rate is 30 - 50 sccm, the sputtering power is 100 - 150 W, the sputtering voltage is 50 - 100 V, and the sputtering temperature is 100 - 150 °C. Deposit Na on the Na 1.0 Mn 0.7 Fe 0.1 Al 0.1 Gd 0.1 O2 layer by magnetron sputtering. The specific conditions for depositing the Na 1.0 Mn 0.7 Fe 0.05 Al 0.05 Gd 0.2 O2 layer are as follows: The magnetron sputtering power supply is a radio frequency power supply, the sputtering atmosphere is an argon atmosphere, the argon flow rate is 30 - 50 sccm, the sputtering power is 200 - 250 W, the sputtering voltage is 100 - 150 V, and the sputtering temperature is 100 - 150 °C.

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