A high-stable and long cycle life lithium ion battery negative electrode material and a preparation method thereof

Abstract

The application discloses a high-stability and long-cycle-life lithium ion battery negative electrode material, which comprises a multilayer Ti3C2T x skeleton, Ti3C2T x skeleton combined Ti3C2T x @TiO2 heterostructure, and Ti3C2T x skeleton combined Ti3C2T x @La2O3 heterostructure. The application integrates the double heterostructures of Ti3C2Tx@TiO2 and Ti3C2Tx@La2O3 in the same electrode, so that the electrode material has the advantages of high conductivity, high capacity and high stability, meanwhile, the double heterostructures effectively improve the rate performance and overall stability of lithium ions, so that the battery can maintain good performance under different current densities.

Description

Technical Field

[0001] The present invention relates to the technical field of lithium-ion batteries, and in particular to a lithium-ion battery negative electrode material with high stability and long cycle life and a preparation method thereof. Background Art

[0002] Lithium-ion batteries are widely used in portable electronic devices, electric vehicles, and energy storage systems due to their high energy density, long cycle life, and lack of memory effect. With the increasing global demand for renewable energy and electric vehicles, the market prospects for lithium-ion batteries are becoming increasingly broad. In addition, with the popularization of portable electronic devices and the rapid development of the electric vehicle industry, the market demand for efficient, portable, and safe energy storage devices is also rising sharply. Advances in energy storage technology can not only support the wider application of renewable energy, but also meet the specific energy storage needs of these emerging fields. Therefore, the development of energy storage technology plays a vital role in promoting energy transformation and promoting environmental protection, but also requires continuous innovation to meet the growing market demand.

[0003] However, while traditional anode materials, such as graphite, perform well in some areas, they still have limitations in terms of long battery life, rapid charge and discharge, and high-temperature stability. In recent years, researchers have been exploring high-performance anode materials to improve overall battery performance. The development of long-life anode materials for lithium-ion batteries has become a key research direction, with silicon-based materials, alloys, and carbon-based composites gaining increasing attention within this context. Despite their high theoretical capacities, these materials experience significant volume expansion during charge and discharge, resulting in poor cycling stability. Therefore, the application of modification and composite technologies is imperative to effectively suppress this expansion and improve cycling efficiency. By optimizing material structure, improving interfacial interactions, and regulating particle size, scientists are working to improve the cycle life and rate performance of anode materials, providing more reliable solutions for future lithium-ion battery applications. This not only advances green energy technology but also has significant implications for promoting a sustainable society.

[0004] The service life and stability of materials are limited by their physical and chemical properties. For example, poor cycle stability leads to a short battery life, which seriously hinders their commercial application. MXene materials, as a new type of transition metal carbonitride, have high intrinsic electronic conductivity and can achieve high-rate charge and discharge. However, their capacity and service life are insufficient. Therefore, current research on MXene is mainly focused on achieving high-capacity composites and designing new morphologies. However, MXene-based lithium-ion battery anode materials still face the following problems:

[0005] 1) The second phase material composited with MXene has poor conductivity and low rate performance;

[0006] 2) MXene-based lithium-ion battery anode materials have poor electrode stability, rapid capacity decay, and short service life;

[0007] 3) The preparation process of MXene-based lithium-ion battery negative electrode materials is complex and the cost is too high, making it difficult to achieve commercial production. Summary of the Invention

[0008] The purpose of the present invention is to provide a highly stable and long cycle life lithium ion battery negative electrode material and a preparation method, which can effectively shorten the migration and diffusion energy barriers of lithium ions in the electrode and improve the structural stability during lithium ion transmission, thereby solving the problems of poor electrochemical stability and short service life of lithium ion battery negative electrode materials during charging and discharging.

[0009] In order to achieve the above objectives, the following technical solutions are adopted:

[0010] A highly stable and long cycle life lithium-ion battery negative electrode material comprising multilayer Ti3C2T x skeleton, and the multilayer Ti3C2T x Skeleton-bonded Ti3C2T x @TiO2 heterostructure, and the multilayer Ti3C2T x Skeleton-bonded Ti3C2T x @La2O3 heterostructure.

[0011] Furthermore, in the negative electrode material, the active material content accounts for 95%, wherein the active material is multilayer Ti3C2T x framework and TiO2 nanoparticles, with La2O3 acting as a structural stabilizer.

[0012] Furthermore, the multilayer Ti3C2T x The diameter of the skeleton is between 3 and 5 μm, and the diameters of TiO2 and La2O3 are between 50 and 100 nm.

[0013] A method for preparing a lithium-ion battery negative electrode material with high stability and long cycle life is also provided, which is used to prepare the above-mentioned negative electrode material, comprising the following steps:

[0014] S1: The MAX phase Ti3AlC2 material is sequentially etched, centrifuged, and freeze-dried to obtain multilayer Ti3C2T x Powder materials;

[0015] S2: a certain mass of multilayer Ti3C2T x The powdered material was dissolved in deionized water and ultrasonicated in an ice bath for a period of time to form solution A;

[0016] S3: add a proper amount of La2O3 precursor material LaN3O9·6H2O to solution A and mix uniformly to form mixed solution B;

[0017] S4: place mixed solution B in a polytetrafluoroethylene reaction kettle, continuously input inert gas Ar2 into the polytetrafluoroethylene reaction kettle for a period of time, then seal the polytetrafluoroethylene reaction kettle and perform hydrothermal reaction;

[0018] S5: filter and clean the product obtained by hydrothermal reaction in S4 to obtain Ti3C2T x @La2O3 heterostructure material, and place it in a vacuum drying box for a period of time to obtain Ti3C2T x @La2O3 powder material;

[0019] S6: add a certain amount of Ti3C2T x @La2O3 powder material to deionized water and perform ultrasonic treatment to obtain a suspension, then place the suspension in a polytetrafluoroethylene reaction kettle, continuously input inert gas Ar2 into the polytetrafluoroethylene reaction kettle to form a low-oxygen atmosphere for a period of time, and perform hydrothermal reaction under the low-oxygen atmosphere;

[0020] S7: filter and clean the product obtained by hydrothermal reaction in S6 to obtain Ti3C2T x @TiO2 / Ti3C2T x @La2O3 double heterostructure material, and perform drying treatment.

[0021] Further, in S1, the MAX phase Ti3AlC2 material is etched by using 20% hydrofluoric acid, and the etched product is added to a mixed solution of deionized water and anhydrous ethanol for centrifugal treatment.

[0022] Further, in S2, the mass of the multi-layer Ti3C2T x powder material is 0.5 g, the deionized water is 20 ml, and the ice bath ultrasonic treatment time is 20 min; in S3, according to the mole ratio of Ti:La elements being 4%, or 8%, or 10%, a corresponding amount of LaN3O9·6H2O is weighed and added to solution A.

[0023] Further, in S4, mixed solution B is placed in a 50 ml polytetrafluoroethylene reaction kettle, and inert gas Ar2 is input into the polytetrafluoroethylene reaction kettle for 15 min, the hydrothermal reaction temperature is 140°C, and the hydrothermal reaction time is 24 h; in S5, the temperature of the vacuum drying box is 70°C, and the drying time is 12 h.

[0024] Further, in S6, the Ti3C2Tx The mass of the La2O3 powder material is 0.5 g, the deionized water is 30 ml, the polytetrafluoroethylene reactor is 50 ml, the time for inputting inert gas Ar2 into the polytetrafluoroethylene reactor is 10 s, the time for the hydrothermal reaction is 12 h, and the temperature of the hydrothermal reaction is 80 ° C. In the above S7, Ti3C2T x @TiO2 / Ti3C2T x The La2O3 double heterostructure material was placed in a vacuum drying oven at 70°C and dried for 12 h.

[0025] By adopting the above scheme, the beneficial effects of the present invention are:

[0026] The present invention integrates Ti3C2T in the same electrode x @TiO2 and Ti3C2T x The double heterostructure of @La2O3 gives the electrode material the advantages of high conductivity, high capacity and high stability. At the same time, this double heterostructure effectively improves the rate performance and overall stability of lithium ions, allowing the battery to maintain good performance at different current densities. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A simplified flow chart of the preparation of negative electrode materials for lithium-ion batteries according to the present invention;

[0028] Figure 2 This is a SEM image of the lithium-ion negative electrode material of the present invention;

[0029] Figure 3 This is a graph showing the rate performance of a lithium-ion negative electrode at different current densities in one embodiment of the present invention;

[0030] Figure 4 This is a graph showing the electrochemical impedance spectroscopy of a lithium-ion negative electrode in one embodiment of the present invention;

[0031] Figure 5 1 is a GCD curve of a lithium-ion negative electrode at a current density of 100 mA / g and different numbers of cycles in one embodiment of the present invention;

[0032] Figure 6 This is a test diagram of the cycling performance of a lithium-ion negative electrode at a current density of 100 mA / g in one embodiment of the present invention;

[0033] Figure 7 This is a long cycle performance test chart of a lithium-ion negative electrode at a current density of 1 A / g in one embodiment of the present invention. DETAILED DESCRIPTION

[0034] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] Referring to Figures 1 to 7 The application provides a high-stability and long-cycle-life lithium ion battery negative electrode material, which comprises a multilayer Ti3C2T x skeleton, Ti3C2T x skeleton-bound Ti3C2T x @TiO2 heterostructure, and Ti3C2T x skeleton-bound Ti3C2T x @La2O3 heterostructure.

[0036] In the embodiment, the multilayer Ti3C2T x is a carrier and a native substance, which belongs to a two-dimensional layered transition metal carbon nitride compound, and further comprises Ti4C3T x , Ti2CT x , V2CT x , Nb2CT x , etc., wherein T x represents a functional group of MXene, which is composed of -OH, -O, -F, -Cl, etc.; TiO2 is a multilayer Ti3C2T x derivative, which is combined with the Ti3C2T x skeleton to increase the electrochemical activity of the material; La2O3 is a structure stabilizer, which is combined with the Ti3C2T x skeleton to improve the structural stability of the material; meanwhile, the content of the active substance is 95%, wherein the active substance is the multilayer Ti3C2T x skeleton and TiO2 nanoparticles.

[0037] In the embodiment, the diameter of the multilayer Ti3C2T x skeleton is between 3 and 5 microns, the diameters of TiO2 and La2O3 are between 50 and 100 nanometers; meanwhile, the multilayer Ti3C2T x skeleton is prepared by etching with hydrofluoric acid, and forms a three-dimensional accordion structure at room temperature, wherein the precursor material is a Ti3AlC2 ceramic material.

[0038] In summary, the negative electrode material of the application exhibits an accordion structure in physical appearance, and a Ti3C2T x @TiO2 / Ti3C2T x @La2O3 double heterostructure in chemical microstructure, that is, the double heterostructure is integrated on the same electrode, and the double heterostructure can effectively reduce the lithium ion migration and diffusion energy barrier, and further optimize the lithium ion transmission path (in actual application, the diameter of the negative electrode material can be tailored to 1.2 cm, and the mass is in the range of 1.5-2 mg).

[0039] A method for preparing a lithium-ion battery negative electrode material with high stability and long cycle life is also provided, which is used to prepare the above-mentioned negative electrode material. The preparation method is a hydrothermal oxidation method, which is to form a multilayer Ti3C2T x The material and the La2O3 precursor are mixed hydrothermally and then hydrothermally oxidized in a low-oxidation atmosphere, specifically comprising the following steps:

[0040] S1: The MAX phase Ti3AlC2 material is sequentially etched, centrifuged, and freeze-dried to obtain multilayer Ti3C2T x Powder material.

[0041] In this step, the MAX phase Ti3AlC2 material is first etched with 20% hydrofluoric acid to remove the Al element in Ti3AlC2, thereby obtaining a Ti3C2Tx (MXene) material composed of Ti, C and N. Subsequently, the etched product is added to a mixture of deionized water and anhydrous ethanol for centrifugation to remove excess acid and by-products. The centrifugation is to separate the solid and liquid in the solution to remove insoluble impurities or collect precipitates. Finally, the obtained solid material is dried by freeze-drying technology to avoid possible chemical changes in the material at high temperatures while maintaining the porous structure and shape of the material.

[0042] S2: a certain mass of multilayer Ti3C2T x The powdered material was dissolved in deionized water and ultrasonically treated in an ice bath for a period of time to form solution A.

[0043] In this step, 0.5 g of multilayer Ti3C2T x The powder material was dissolved in 20 ml of deionized water and ultrasonically treated in an ice bath for 20 min to fully disperse the solid particles in the solution to form a uniform solution A.

[0044] S3: Add an appropriate amount of La2O3 precursor material LaN3O9·6H2O to solution A and mix them evenly to form a mixed solution B.

[0045] In this step, first, according to the molar ratio of Ti:La elements being 4%, 8%, or 10%, a corresponding amount of LaN3O9·6H2O is weighed and added to solution A, and mixed evenly to form a mixed solution B.

[0046] S4: placing the mixed liquid B in a polytetrafluoroethylene reactor, and continuously inputting inert gas Ar2 into the polytetrafluoroethylene reactor for a period of time. Subsequently, the polytetrafluoroethylene reactor is sealed and a hydrothermal reaction is performed.

[0047] In this step, the mixed solution B is first placed in a 50ml polytetrafluoroethylene reactor, and then the inert gas Ar2 is continuously introduced into the polytetrafluoroethylene reactor for 15 minutes to remove the air in the reactor and prevent oxygen and moisture from interfering with the reaction, thereby avoiding possible side reactions. Subsequently, the polytetrafluoroethylene reactor is sealed and a hydrothermal reaction is carried out. The hydrothermal reaction temperature is 140°C and the hydrothermal reaction time is 24 hours. Under these conditions, LaN3O9·6H2O will be converted into La2O3 and react with Ti3C2T x Forming a composite material.

[0048] S5: The product obtained by the hydrothermal reaction in S4 is filtered and cleaned to obtain Ti3C2T x @La2O3 heterostructure material, and place it in a vacuum drying oven and dry it for a period of time to obtain Ti3C2T x @La2O3 powder material.

[0049] In this step, the product obtained by the hydrothermal reaction is first filtered and cleaned to remove unreacted raw materials, by-products or other impurities to obtain Ti3C2T x The La2O3 heterostructure material was then placed in a vacuum drying oven at 70°C for 12 hours to remove moisture and obtain Ti3C2T x @La2O3 powder material.

[0050] S6: Add a certain amount of Ti3C2T x @La2O3 powder material is added to deionized water and ultrasonically treated to obtain a suspension. The suspension is then placed in a polytetrafluoroethylene reactor, and inert gas Ar2 is continuously introduced into the polytetrafluoroethylene reactor for a period of time to form a low-oxygen atmosphere, and then a hydrothermal reaction is carried out in the low-oxygen atmosphere.

[0051] In this step, 0.5 g of Ti3C2T x The La2O3 powder material was added to 30 ml of deionized water and ultrasonically treated to uniformly disperse the powder in the water to form a suspension. Subsequently, the obtained suspension was placed in a 50 ml polytetrafluoroethylene reactor and introduced with inert gas Ar2 for 10 seconds to exhaust the air in the reactor and form a low oxygen environment. Finally, a hydrothermal reaction was carried out in the low oxygen atmosphere to make Ti3C2T x TiO2 was in situ grown on the surface of La2O3 powder, wherein the hydrothermal reaction time was 12 h and the hydrothermal reaction temperature was 80°C.

[0052] S7: The product obtained by the hydrothermal reaction of S6 is filtered and cleaned to obtain Ti3C2T x @TiO2 / Ti3C2Tx @La2O3 double heterostructure material and dry it.

[0053] In this step, the product obtained by the hydrothermal reaction in step S6 is first filtered and cleaned to remove unreacted raw materials, by-products or other impurities to obtain a double heterostructure material containing Ti3C2Tx@TiO2 and Ti3C2Tx@La2O3, and the obtained material is placed in a vacuum drying oven at 70°C and dried for 12 hours to remove moisture, finally obtaining a dry negative electrode material with high stability and long cycle life.

[0054] The Ti3C2T prepared by the above method x @TiO2 / Ti3C2T x @La2O3 double heterostructure materials can be named ML4, ML8, ML10 according to different molar ratios (4%, 8%, 10%), such as Figure 2 As shown in the figure, TiO2 and a small amount of La2O3 nanoparticles are evenly distributed in the multilayer Ti3C2T x layer, where multilayer Ti3C2T x The total mass ratio of TiO2 and La2O3 is about 95%, and the mass ratio of La2O3 is 5%. At the same time, the material prepared by the above method can be directly used in lithium-ion batteries, in which the electrolyte is lithium hexafluorophosphate, ethylene carbonate and dimethyl carbonate. In addition, the battery negative electrode material prepared by the above method has a unique Ti3C2T x @TiO2 and Ti3C2T x @La2O3 double heterostructure, in which Ti3C2T x It plays a role in improving the electronic conductivity and active materials of the composite material. TiO2 prepared by low-temperature in-situ oxidation strategy is the active material, and La2O3 plays a role in stabilizing the structure. At the same time, this double heterogeneous structure can effectively reduce the migration and diffusion energy barriers of lithium ions, optimize the ion transmission path, stabilize the electrode microstructure, and thus improve the long-cycle performance of the electrode and increase the battery life.

[0055] In one embodiment, a negative electrode sheet is provided, comprising a current collector, a conductive agent, a binder, and the negative electrode material described above, attached to at least one side of the current collector. In this embodiment, the electrode sheet is prepared by coating, wherein the ratio of active material: conductive agent: binder is 8:1:1.

[0056] In one embodiment, a battery is provided, comprising a positive electrode sheet, a separator, an electrolyte, a battery casing, and the aforementioned negative electrode sheet. The electrode sheet can be assembled into the lithium-ion battery casing through processes such as pressing and weighing. The electrolyte comprises lithium hexafluorophosphate, ethylene carbonate, and dimethyl carbonate.

[0057] The Ti3C2T x @TiO2 / Ti3C2T x @La2O3 double heterostructure material was tested as a lithium ion battery anode, where the rate performance test current densities were 50 mA / g, 100 mA / g, 200 mA / g, 500 mA / g, 1 A / g, 2 A / g, and 5 A / g, and then returned to 50 mA / g; the long cycle performance test current densities were 100 mA / g and 1 A / g. The test results showed that when the Ti: La element molar ratio was 100:4, the material had the optimal performance.

[0058] Meanwhile, the Ti3C2T x @TiO2 / Ti3C2T x @La2O3 double heterostructure material prepared above was directly used as a lithium ion anode, and in the test of lithium ion battery rate performance, as shown in Figure 3 , when the test current densities were 50 mA / g, 100 mA / g, 200 mA / g, 500 mA / g, 1 A / g, 2 A / g, and 5 A / g, the capacities were 449, 191, 163, 121, 102, 79, and 59 mAh / g, respectively, after 5 cycles.

[0059] The test results showed that the Ti3C2T x @TiO2 / Ti3C2T x @La2O3 double heterostructure material prepared in the above examples directly used as a lithium ion anode showed low impedance Figure 4 , which explained its high rate performance.

[0060] Meanwhile, as shown in Figure 5 , the Ti3C2T x @TiO2 / Ti3C2T x @La2O3 double heterostructure electrode prepared above had a low working current of 100 mA / g -1 , and after 800 cycles, the galvanostatic charge-discharge curve (GCD) remained unchanged, having good chemical stability.

[0061] As shown in Figure 6 , when the long cycle performance of a lithium ion battery was tested, the current density was 100 mA / g, and the lithium ion battery assembled from the Ti3C2T x @TiO2 / Ti3C2T x @La2O3 double heterostructure material had a capacity of 319 mAh / g after 800 cycles.

[0062] The test results showed that, as shown in Figure 7 , when the current density was 1 A / g, the Ti3C2T x@TiO2 / Ti3C2T x The capacity retention rate of the lithium-ion battery assembled with La2O3 double heterostructure materials was 101% after 10,000 cycles.

[0063] The low-temperature hydrothermal oxidation strategy in this invention can be extended to MXene materials with high theoretical specific capacity derivatives but low conductivity and poor stability, such as V2CT x 、Mo2CT x etc., which is beneficial to improving the chemical stability of the electrode and increasing the service life of the electrode. At the same time, the lithium ion battery negative electrode provided by the present invention has the following advantages:

[0064] First of all, the synthesis method is relatively simple. Ti3C2T can be obtained through hydrothermal and low oxidation atmosphere hydrothermal processes. x @TiO2 / Ti3C2T x @La2O3 double heterostructure. At the same time, this double heterostructure electrode material has the advantages of high stability and long cycle life. Moreover, the simple preparation process and operation process are suitable for large-scale industrial production.

[0065] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A lithium-ion battery negative electrode material with high stability and long cycle life, characterized in that: Including multilayer Ti3C2T x skeleton, and the multilayer Ti3C2T x Skeleton-bonded Ti3C2T x @TiO2 heterostructure, and the multilayer Ti3C2T x Skeleton-bonded Ti3C2T x @La2O3 heterogeneous structure, the preparation method of the negative electrode material includes the following steps: S1: The MAX phase Ti3AlC2 material is sequentially etched, centrifuged, and freeze-dried to obtain multilayer Ti3C2T x Powder materials; S2: a certain mass of multilayer Ti3C2T x The powdered material was dissolved in deionized water and ultrasonicated in an ice bath for a period of time to form solution A; S3: Add an appropriate amount of La2O3 precursor material LaN3O9·6H2O to solution A and mix them evenly to form a mixed solution B; S4: placing the mixed solution B in a polytetrafluoroethylene reactor, and continuously introducing inert gas Ar2 into the polytetrafluoroethylene reactor for a period of time, then sealing the polytetrafluoroethylene reactor and performing a hydrothermal reaction; S5: The product obtained by the hydrothermal reaction in S4 is filtered and cleaned to obtain Ti3C2T x @La2O3 heterostructure material, and place it in a vacuum drying oven and dry it for a period of time to obtain Ti3C2T x @La2O3 powder material; S6: Add a certain amount of Ti3C2T x La2O3 powder is added to deionized water and ultrasonically treated to obtain a suspension. The suspension is then placed in a polytetrafluoroethylene reactor. Inert gas Ar2 is continuously introduced into the reactor over a period of time to form a low-oxygen atmosphere, and a hydrothermal reaction is then carried out in the low-oxygen atmosphere. S7: The product obtained by the hydrothermal reaction of S6 is filtered and cleaned to obtain Ti3C2T x @TiO2 / Ti3C2T x @La2O3 double heterostructure material and dry it.

2. The highly stable and long cycle life lithium ion battery negative electrode material according to claim 1, characterized in that: In the negative electrode material, the active material content accounts for 95%, wherein the active material is multilayer Ti3C2T x framework and TiO2 nanoparticles, with La2O3 acting as a structural stabilizer.

3. The highly stable and long cycle life lithium ion battery negative electrode material according to claim 1, characterized in that: The multilayer Ti3C2T x The diameter of the skeleton is between 3 and 5 μm, and the diameters of TiO2 and La2O3 are between 50 and 100 nm.

4. A method for preparing a lithium-ion battery negative electrode material with high stability and long cycle life, for preparing the negative electrode material according to any one of claims 1 to 3, characterized in that: The steps include: S1: The MAX phase Ti3AlC2 material is sequentially etched, centrifuged, and freeze-dried to obtain multilayer Ti3C2T x Powder materials; S2: a certain mass of multilayer Ti3C2T x The powdered material was dissolved in deionized water and ultrasonicated in an ice bath for a period of time to form solution A; S3: Add an appropriate amount of La2O3 precursor material LaN3O9·6H2O to solution A and mix them evenly to form a mixed solution B; S4: placing the mixed solution B in a polytetrafluoroethylene reactor, and continuously introducing inert gas Ar2 into the polytetrafluoroethylene reactor for a period of time, then sealing the polytetrafluoroethylene reactor and performing a hydrothermal reaction; S5: The product obtained by the hydrothermal reaction in S4 is filtered and cleaned to obtain Ti3C2T x @La2O3 heterostructure material, and place it in a vacuum drying oven and dry it for a period of time to obtain Ti3C2T x @La2O3 powder material; S6: Add a certain amount of Ti3C2T x La2O3 powder is added to deionized water and ultrasonically treated to obtain a suspension. The suspension is then placed in a polytetrafluoroethylene reactor. Inert gas Ar2 is continuously introduced into the reactor over a period of time to form a low-oxygen atmosphere, and a hydrothermal reaction is then carried out in the low-oxygen atmosphere. S7: The product obtained by the hydrothermal reaction of S6 is filtered and cleaned to obtain Ti3C2T x @TiO2 / Ti3C2T x @La2O3 double heterostructure material and dry it.

5. The method for preparing a lithium-ion battery negative electrode material with high stability and long cycle life according to claim 4, characterized in that: In the above-mentioned S1, the MAX phase Ti3AlC2 material is etched by using hydrofluoric acid with a concentration of 20%, and the etched product is added to a mixture of deionized water and anhydrous ethanol for centrifugal treatment.

6. The method for preparing a lithium-ion battery negative electrode material with high stability and long cycle life according to claim 4, characterized in that: In the S2, multilayer Ti3C2T x The mass of the powder material is 0.5 g, the amount of deionized water is 20 ml, and the time of ice bath ultrasonic treatment is 20 min. In S3, the corresponding amount of LaN3O9·6H2O is weighed and added to solution A according to the molar ratio of Ti:La element of 4%, 8%, or 10%.

7. The method for preparing a lithium-ion battery negative electrode material with high stability and long cycle life according to claim 4, characterized in that: In S4, the mixed liquid B is placed in a 50 ml polytetrafluoroethylene reactor, and the time for inputting inert gas Ar2 into the polytetrafluoroethylene reactor is 15 minutes, the temperature of the hydrothermal reaction is 140°C, and the hydrothermal reaction time is 24 hours; in S5, the temperature of the vacuum drying oven is 70°C, and the drying time is 12 hours.

8. The method for preparing a lithium-ion battery negative electrode material with high stability and long cycle life according to claim 4, characterized in that: The S6, Ti3C2T x The mass of the La2O3 powder material is 0.5 g, the deionized water is 30 ml, the polytetrafluoroethylene reactor is 50 ml, the time for inputting inert gas Ar2 into the polytetrafluoroethylene reactor is 10 s, the time for the hydrothermal reaction is 12 h, and the temperature of the hydrothermal reaction is 80 ° C. In the above S7, Ti3C2T x @TiO2 / Ti3C2T x The La2O3 double heterostructure material was placed in a vacuum drying oven at 70°C and dried for 12 h.

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