High-entropy oxide composite negative electrode material and preparation method and application thereof

Abstract

The invention discloses a high-entropy oxide composite negative electrode material as well as a preparation method and application thereof, and relates to the technical field of all-solid-state lithium battery negative electrode materials, and the high-entropy oxide composite negative electrode material comprises a metal element and an oxygen element, the high-entropy oxide composite negative electrode material comprises a metal element and an oxygen element, wherein the metal elements are at least five of a chromium element, an iron element, a nickel element, a manganese element, a molybdenum element, a copper element and a cerium element; the molar ratio of the metal element to the oxygen element is 3: 4; the high-entropy oxide composite negative electrode material is of a spinel structure. According to the prepared high-entropy oxide composite negative electrode material, the problems that a traditional negative electrode material is unstable in structure, poor in interface contact and short in cycle life are solved, the electrochemical performance is improved, and an all-solid-state lithium battery prepared from the high-entropy oxide composite negative electrode material shows high reversible specific capacity and excellent cycle stability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of all-solid-state lithium battery negative electrode materials, and in particular to a high-entropy oxide composite negative electrode material and a preparation method and application thereof. BACKGROUND

[0002] Current commercial lithium-ion batteries generally use a liquid electrolyte system, which is mature in technology, but has safety hazards of flammability and explosion of electrolyte and energy density improvement bottlenecks. To solve these problems, all-solid-state lithium batteries have become an important development direction for next-generation energy storage devices due to their higher safety and higher energy density.

[0003] In an all-solid-state battery system, the selection of a negative electrode material is particularly critical. Traditional graphite negative electrodes have limited capacity and are difficult to meet high energy requirements. Metal lithium negative electrodes have ultra-high theoretical capacity, but have problems of dendrite growth and interface contact. Conventional conversion-type metal oxide negative electrodes have high capacity, but face problems such as large volume expansion and poor cycle stability.

[0004] Therefore, it is urgent to develop a new negative electrode material with stable structure, high capacity and good interface compatibility. SUMMARY

[0005] The present application aims to provide a high-entropy oxide composite negative electrode material and a preparation method and application thereof, to solve the problems of structural instability, poor interface contact and short cycle life of traditional negative electrode materials.

[0006] To achieve the above-mentioned purpose, the present application provides a high-entropy oxide composite negative electrode material, comprising: metal elements and oxygen elements; the metal elements are at least five of chromium elements, iron elements, nickel elements, manganese elements, molybdenum elements, copper elements and cerium elements; the molar ratio of the metal elements and the oxygen elements is 3:4; the high-entropy oxide composite negative electrode material is a spinel structure.

[0007] Preferably, the metal elements are chromium elements, iron elements, nickel elements, manganese elements and molybdenum elements, and the molar ratio is 1:1:1:1:1; the metal elements are chromium elements, iron elements, nickel elements, manganese elements and copper elements, and the molar ratio is 1:1:1:1:1; the metal elements are chromium elements, iron elements, nickel elements, manganese elements, molybdenum elements and cerium elements, and the molar ratio is 1:1:1:1:1:1.

[0008] Preferably, the high-entropy oxide composite negative electrode material is a sub-micron particle; the high-entropy oxide composite negative electrode material is prepared by a ball milling-sintering method.

[0009] The present application provides a preparation method of a high-entropy oxide composite negative electrode material, for preparing the above-mentioned high-entropy oxide composite negative electrode material, comprising the following steps: S1, mixing metal oxides to obtain mixed metal oxides, and adding a solvent to perform high-energy ball milling to obtain a ball-milled slurry; S2, drying and sieving the ball-milled slurry to obtain a uniformly mixed precursor powder; S3, sintering the precursor powder in an air atmosphere to obtain a high-entropy oxide composite negative electrode material.

[0010] Preferably, the solvent is anhydrous alcohol.

[0011] Preferably, in S1, the mass-volume ratio of the mixed metal oxides and anhydrous alcohol is (5-6) g: 3 mL; the mixed metal oxides are at least five of chromium oxide, iron oxide, nickel oxide, manganese oxide, molybdenum oxide, copper oxide, and cerium oxide.

[0012] Preferably, in S1, the rotation speed of high-energy ball milling is 800 r / min, and the rotation direction is alternately forward and reverse, and the total effective ball milling time is 2 h.

[0013] Preferably, in S2, the drying temperature is 80℃, and the drying time is 10 h.

[0014] Preferably, in S3, the sintering is performed at a heating rate of 5℃ / min to 800℃-1000℃, and the holding time is 10 h.

[0015] The application also provides an application of the high-entropy oxide composite negative electrode material, which is applied to a full-solid-state lithium battery negative electrode.

[0016] In summary, the high-entropy oxide composite negative electrode material, its preparation method and application provided by the application have the following beneficial effects compared with the prior art: (1) The high-entropy oxide composite negative electrode material prepared by the application effectively suppresses particle pulverization and electrode structure collapse through the synergistic effect of multiple metal elements and the entropy stabilization effect, significantly improves the structural stability, optimizes the electronic conductivity, ion diffusion kinetics and structural buffering capacity, and improves the overall electrochemical performance; the high-entropy oxide composite negative electrode material has a spinel structure, has good interface contact with a sulfide solid-state electrolyte, is not prone to side reactions, and the negative electrode sheet and the electrolyte still maintain close contact after cycling, avoiding interface peeling caused by volume change and improving the long-term cycle stability of the full-solid-state battery.

[0017] (2) The negative electrode prepared from the high-entropy oxide composite negative electrode material exhibits high reversible specific capacity and excellent cycle stability.

[0018] (3) The high-entropy oxide composite negative electrode material reveals a universal design idea for solving the technical bottleneck of full-solid-state negative electrodes by constructing a multi-main-element high-entropy oxide system.

[0019] The technical method of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0020] Figure 1 The high-entropy oxide (Cr) in Example 1 0.2 Fe 0.2 Ni 0.2 Mn 0.2 Mo 0.2 Scanning Electron Microscope (SEM) image of 3O4; Figure 2 The high-entropy oxide (Cr) in Example 2 0.2 Fe 0.2 Ni 0.2 Mn 0.2 Cu 0.2 SEM image of 3O4; Figure 3 The high-entropy oxide (Cr) in Example 3 0.2 Fe 0.2 Ni 0.2 Mn 0.2 Mo 0.2 Ce 0.2 SEM image of 3O4; Figure 4 The high-entropy oxide (Cr) in Example 1 0.2 Fe 0.2 Ni 0.2 Mn 0.2 Mo 0.2 X-ray diffraction (XRD) pattern of 3O4; Figure 5 The high-entropy oxide (Cr) in Example 2 0.2 Fe 0.2 Ni 0.2 Mn 0.2 Cu 0.2 XRD pattern of 3O4; Figure 6 The high-entropy oxide (Cr) in Example 3 0.2 Fe 0.2 Ni 0.2 Mn 0.2 Mo 0.2 Ce 0.2 XRD pattern of 3O4; Figure 7 For high-entropy oxides (Cr) 0.2 Fe 0.2 Ni 0.2 Mn0.2 Mo 0.2 The first charge-discharge curve of the all-solid-state lithium battery prepared by 3O4; Figure 8 For high-entropy oxides (Cr) 0.2 Fe 0.2 Ni 0.2 Mn 0.2 Mo 0.2 Cycling performance curves of all-solid-state lithium batteries prepared by 3O4 at 0.1C rate (current density of about 100 mA / g); Figure 9 For high-entropy oxides (Cr) 0.2 Fe 0.2 Ni 0.2 Mn 0.2 Mo 0.2 Rate performance curve of all-solid-state lithium battery prepared by 3O4; Figure 10 For high-entropy oxides (Cr) 0.2 Fe 0.2 Ni 0.2 Mn 0.2 Cu 0.2 The first charge-discharge curve of the all-solid-state lithium battery prepared by 3O4; Figure 11 For high-entropy oxides (Cr) 0.2 Fe 0.2 Ni 0.2 Mn 0.2 Cu 0.2 Cycling performance curves of all-solid-state lithium batteries prepared by 3O4 at 0.1C rate; Figure 12 For high-entropy oxides (Cr) 0.2 Fe 0.2 Ni 0.2 Mn 0.2 Cu 0.2 Rate performance curve of all-solid-state lithium battery prepared by 3O4; Figure 13 For high-entropy oxides (Cr) 0.2 Fe 0.2 Ni 0.2 Mn 0.2 Mo 0.2 Ce 0.2 The first charge-discharge curve of the all-solid-state lithium battery prepared by 3O4; Figure 14 For high-entropy oxides (Cr) 0.2 Fe 0.2 Ni 0.2 Mn 0.2 Mo 0.2 Ce0.2 Cycling performance curves of all-solid-state lithium batteries prepared by 3O4 at 0.1C rate; Figure 15 For high-entropy oxides (Cr) 0.2 Fe 0.2 Ni 0.2 Mn 0.2 Mo 0.2 Ce 0.2 Rate performance curve of all-solid-state lithium battery prepared by 3O4; Figure 16 For high-entropy oxides (Cr) 0.2 Fe 0.2 Ni 0.2 Mn 0.2 Mo 0.2 SEM images of the composite negative electrode sheet of the all-solid-state lithium battery prepared by 3O4 before and after cycling; where: Figure 16 (a) is a surface SEM image of the composite negative electrode sheet before cycling; Figure 16 (b) is a cross-sectional SEM image of the composite negative electrode sheet before cycling; Figure 16 (c) is a surface SEM image of the composite negative electrode sheet after cycling; Figure 16 (d) is a cross-sectional SEM image of the composite negative electrode sheet after cycling. Detailed Implementation

[0021] The technical method of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0022] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.

[0023] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0024] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0025] The specific implementation examples are as follows: Example 1 A method for preparing a high-entropy oxide composite anode material includes the following steps: (1) Weigh 0.76g of chromium oxide (Cr2O3), 0.7985g of iron oxide (Fe2O3), 0.7469g of nickel oxide (NiO), 0.8694g of manganese oxide (MnO2) and 1.2794g of molybdenum oxide (Mo3O4) and mix them as precursors.

[0026] (2) Place the precursor in a zirconia grinding jar and add zirconia grinding beads with a mass 10 times the total mass of the precursor as the grinding medium. Then add 3 mL of anhydrous ethanol. The anhydrous ethanol serves to cool and protect the precursor, and its amount is just enough to submerge the precursor and the zirconia grinding beads.

[0027] (3) After adding anhydrous alcohol, seal the ball mill jar and fix it on a planetary ball mill. Then, rotate the ball mill at 800 r / min and repeat the cycle twice: "30 min forward, 10 min rest, 30 min reverse, 10 min rest" to obtain the ball mill slurry. The ball milling process aims to achieve thorough mixing and pre-activation of the precursor and anhydrous alcohol at the atomic scale.

[0028] (4) Place the ball milled slurry in a forced-air drying oven and dry it continuously at 80°C for 10 hours to completely remove the alcohol solvent. Then pass it through a 200-mesh sieve to obtain a uniformly mixed precursor powder.

[0029] (5) Transfer the precursor powder to an alumina ceramic crucible and compact it. Then place the alumina ceramic crucible into a box-type muffle furnace and sinter it at a heating rate of 3℃ / min from room temperature to 1000℃ for 10h in an air atmosphere. Then let it cool naturally to room temperature with the furnace to obtain a black block sintered body.

[0030] (6) Grind the blocky sintered body and pass it through a 400-mesh sieve to obtain a spinel-structured high-entropy oxide composite anode material, namely, high-entropy oxide (Cr). 0.2 Fe 0.2 Ni 0.2 Mn 0.2 Mo 0.2 )3O4, its SEM image is as follows Figure 1 As shown.

[0031] This invention employs a high-temperature solid-state method for one-step synthesis of high-entropy oxides (Cr). 0.2 Fe 0.2 Ni 0.2 Mn 0.2 Mo 0.2 3O4 anode material has a simple operation process, low cost, and no pollution.

[0032] Example 2 A method for preparing a high-entropy oxide composite anode material includes the following steps: (1) Weigh 0.76g of chromium oxide (Cr2O3), 0.7985g of iron oxide (Fe2O3), 0.7469g of nickel oxide (NiO), 0.8694g of manganese oxide (MnO2) and 0.7954g of copper oxide (CuO) and mix them as precursors.

[0033] (2) Place the precursor in a zirconia grinding jar and add zirconia grinding beads with a mass 10 times the total mass of the precursor as the grinding medium. Then add 3 mL of anhydrous ethanol. The anhydrous ethanol serves to cool and protect the precursor, and its amount is just enough to submerge the precursor and the zirconia grinding beads.

[0034] (3) After adding anhydrous alcohol, seal the ball mill jar and fix it on a planetary ball mill. Then, rotate the ball mill at 800 r / min and repeat the cycle twice: "30 min forward, 10 min rest, 30 min reverse, 10 min rest" to obtain the ball mill slurry. The ball milling process aims to achieve thorough mixing and pre-activation of the precursor and anhydrous alcohol at the atomic scale.

[0035] (4) Place the ball milled slurry in a forced-air drying oven and dry it continuously at 80°C for 10 hours to completely remove the alcohol solvent. Then pass it through a 200-mesh sieve to obtain a uniformly mixed precursor powder.

[0036] (5) Transfer the precursor powder to an alumina ceramic crucible and compact it. Then place the alumina ceramic crucible into a box-type muffle furnace and sinter it at a heating rate of 3℃ / min from room temperature to 900℃ for 10h in an air atmosphere. Then let it cool naturally to room temperature with the furnace to obtain a black block sintered body.

[0037] (6) Grind the blocky sintered body and pass it through a 400-mesh sieve to obtain a spinel-structured high-entropy oxide composite anode material, namely, high-entropy oxide (Cr). 0.2 Fe 0.2 Ni 0.2 Mn 0.2 Cu 0.2 )3O4, its SEM image is as follows Figure 2 As shown.

[0038] Example 3 A method for preparing a high-entropy oxide composite anode material includes the following steps: (1) Weigh 0.76g of chromium oxide (Cr2O3), 0.7985g of iron oxide (Fe2O3), 0.7469g of nickel oxide (NiO), 0.8694g of manganese oxide (MnO2), 0.7954g of molybdenum oxide (Mo3O4) and 0.86g of cerium oxide (CeO2) and mix them as precursors.

[0039] (2) Place the precursor in a zirconia grinding jar and add zirconia grinding beads with a mass 10 times the total mass of the precursor as the grinding medium. Then add 3 mL of anhydrous ethanol. The anhydrous ethanol serves to cool and protect the precursor, and its amount is just enough to submerge the precursor and the zirconia grinding beads.

[0040] (3) After adding anhydrous alcohol, seal the ball mill jar and fix it on a planetary ball mill. Then, rotate the ball mill at 800 r / min and repeat the cycle twice: "30 min forward, 10 min rest, 30 min reverse, 10 min rest" to obtain the ball mill slurry. The ball milling process aims to achieve thorough mixing and pre-activation of the precursor and anhydrous alcohol at the atomic scale.

[0041] (4) Place the ball milled slurry in a forced-air drying oven and dry it continuously at 80°C for 10 hours to completely remove the alcohol solvent. Then pass it through a 400-mesh sieve to obtain a uniformly mixed precursor powder.

[0042] (5) Transfer the precursor powder to an alumina ceramic crucible and compact it. Then place the alumina ceramic crucible into a box-type muffle furnace and sinter it at a heating rate of 3℃ / min from room temperature to 900℃ for 10h in an air atmosphere. Then let it cool naturally to room temperature with the furnace to obtain a black block sintered body.

[0043] (6) Grind the blocky sintered body and pass it through a 400-mesh sieve to obtain a spinel-structured high-entropy oxide composite anode material, namely, high-entropy oxide (Cr). 0.2 Fe 0.2 Ni 0.2 Mn 0.2 Mo 0.2 Ce)3O4, its SEM image is as follows Figure 3 As shown.

[0044] The high-entropy oxide (Cr) in Example 1 0.2 Fe 0.2 Ni 0.2 Mn 0.2 Mo 0.2 )3O4, the high-entropy oxide (Cr) in Example 2 0.2 Fe 0.2 Ni 0.2 Mn 0.2 Cu 0.2 )3O4 and the high-entropy oxide (Cr) in Example 3 0.2 Fe 0.2 Ni 0.2 Mn 0.2 Mo 0.2 Ce)3O4 all have a spinel structure.

[0045] like Figure 4 As shown, high-entropy oxides (Cr 0.2 Fe 0.2 Ni 0.2 Mn 0.2 Mo 0.2In the XRD pattern of MnMoO4, distinct diffraction peaks appear at 18.4°, 30.2°, 35.6°, 37.1°, 43.2°, 53.8°, 57.3°, and 62.9°, corresponding to the (111), (220), (311), (222), (400), (422), (511), and (440) crystal planes, respectively. These peaks are consistent with the diffraction characteristics of the standard spinel phase, indicating that the material has a typical spinel crystal structure. In addition to the main spinel structure, a small portion of monoclinic MnMoO4 also exists.

[0046] like Figure 5 As shown, high-entropy oxides (Cr 0.2 Fe 0.2 Ni 0.2 Mn 0.2 Cu 0.2 In the XRD pattern of 3O4, obvious diffraction peaks appear at 18.4°, 30.2°, 35.6°, 37.1°, 43.2°, 53.8°, 57.3° and 62.9°, which correspond to the (111), (220), (311), (222), (400), (422), (511) and (440) crystal planes, respectively. These peaks are consistent with the diffraction characteristics of the standard spinel phase, indicating that the material has a typical spinel crystal structure.

[0047] like Figure 6 As shown, high-entropy oxides (Cr 0.2 Fe 0.2 Ni 0.2 Mn 0.2 Mo 0.2 Ce 0.2 In the XRD pattern of 3O4, obvious diffraction peaks appear at 18.4°, 30.2°, 35.6°, 37.1°, 43.2°, 53.8°, 57.3° and 62.9°, which correspond to the (111), (220), (311), (222), (400), (422), (511) and (440) crystal planes, respectively. These peaks are consistent with the diffraction characteristics of the standard spinel phase, indicating that the material has a typical spinel crystal structure.

[0048] High entropy oxides (Cr) 0.2 Fe 0.2 Ni 0.2 Mn 0.2 Mo 0.2 A composite negative electrode sheet is prepared by mixing 3O4, a sulfide electrolyte (such as LiSiPSCl), and a conductive agent (such as vapor-grown carbon fiber) in a mass ratio of 6:3:1. This negative electrode sheet is then combined with the positive electrode and a solid electrolyte layer in a glove box using a cold pressing method to prepare an all-solid-state lithium battery, designated as No. 1 all-solid-state lithium battery. Figure 7As shown, the No. 1 all-solid-state lithium battery has a first discharge specific capacity of 976mAh / g, which is higher than that of traditional graphite anodes.

[0049] like Figure 8 As shown, after 5 cycles at a 0.05C rate (current density approximately 50 mA / g), the discharge capacity of the No. 1 all-solid-state lithium battery reaches 610 mAh / g after approximately 10 cycles at a 0.1C rate, and then almost stops decreasing. The capacity retention rate thereafter reaches 100%, and even shows a certain upward trend. Regarding the rate performance of the No. 1 all-solid-state lithium battery, as... Figure 9 As shown, although the discharge specific capacity decreases significantly at higher rates, it can still recover to a level close to that at the initial low rate when the discharge rate is restored, indicating good rate performance.

[0050] High entropy oxides (Cr) 0.2 Fe 0.2 Ni 0.2 Mn 0.2 Cu 0.2 A composite negative electrode sheet is prepared by mixing 3O4, a sulfide electrolyte (such as LiSiPSCl), and a conductive agent (such as vapor-grown carbon fiber) in a mass ratio of 6:3:1. This negative electrode sheet is then combined with the positive electrode and a solid electrolyte layer in a glove box using a cold pressing method to prepare an all-solid-state lithium battery, designated as No. 2 all-solid-state lithium battery. Figure 10 As shown, the No. 2 all-solid-state lithium battery has an initial discharge specific capacity of 1238mAh / g, which is higher than that of traditional graphite anodes.

[0051] like Figure 11 As shown, the No. 2 all-solid-state lithium battery underwent 5 cycles at a 0.05C rate (current density approximately 50 mA / g). At a 0.1C rate, its cycle capacity continuously decreased, reaching 432 mAh / g after 50 cycles. However, the rate of decrease is slowing, and it is predicted to stabilize between 300 mAh / g and 400 mAh / g. While not as good as high-entropy oxides of Mo, its initial capacity is high, and subsequent modifications can improve its cycle stability. Figure 12 As shown, the No. 2 all-solid-state lithium battery exhibits a specific capacity close to 785 mAh / g at low rate (0.05C) and remains stable during cycling. However, the capacity gradually decreases with increasing rate, decreasing sequentially at 0.1C, 0.2C, 0.5C, 1.0C, and 2.0C, with a significant decrease at the high rate of 2.0C. This indicates that the No. 2 all-solid-state lithium battery possesses excellent electrochemical performance at low to medium rates, but its ion / electron transport capability is limited at high rates, making it suitable for low to medium rate applications. Furthermore, the No. 2 all-solid-state lithium battery's capacity partially recovers after rate recovery, demonstrating a degree of reversibility and stability in its structure.

[0052] High entropy oxides (Cr)0.2 Fe 0.2 Ni 0.2 Mn 0.2 Mo 0.2 A composite negative electrode sheet is prepared by mixing Ce)3O4, a sulfide electrolyte (such as LiSiPSCl), and a conductive agent (such as vapor-grown carbon fiber) in a mass ratio of 6:3:1. This negative electrode sheet is then combined with the positive electrode and a solid electrolyte layer in a glove box using a cold pressing method to prepare an all-solid-state lithium battery, designated as No. 3 all-solid-state lithium battery. Figure 13 As shown, the No. 3 all-solid-state lithium battery has an initial discharge specific capacity of 789 mAh / g, which is higher than that of traditional graphite anodes.

[0053] like Figure 14 As shown, the No. 3 all-solid-state lithium battery, after 5 cycles at a 0.05C rate (current density approximately 50 mA / g), reaches a discharge capacity of 238 mAh / g after approximately 50 cycles at a 0.1C rate. However, based on the patterns observed in liquid batteries, a similar trend of initial decrease followed by capacity increase should also occur in solid-state batteries. Figure 15 As shown, under low-rate conditions such as 0.05C and 0.1C, the No. 3 all-solid-state lithium battery exhibits an excellent initial discharge specific capacity of 798 mAh g. -1 Furthermore, it remains stable within a limited number of cycles. As the rate increases progressively to 0.2C, 1C, 2C, and even 5C, its discharge specific capacity exhibits a stepwise decrease, especially at the high rate of 5C where the capacity has already dropped to a relatively low level. Overall, the No. 3 all-solid-state lithium battery is quite sensitive to rate changes, with significant performance degradation at high rates, indicating that it is more suitable for medium and low rate operating scenarios; and the initial capacity degradation at each rate also conforms to the common variation patterns of electrode materials.

[0054] To verify the structural stability, SEM analysis was performed on the negative electrode of the No. 1 all-solid-state lithium battery before and after cycling, such as... Figure 16 As shown. According to Figure 16 (a) Figure 16 (b) Figure 16 (c) and Figure 16 (d) It can be seen that by comparing the morphology of the negative electrode surface and cross-section before and after cycling of the No. 1 all-solid-state lithium battery, it can be seen that the high-entropy oxide (Cr) 0.2 Fe 0.2 Ni 0.2 Mn 0.2 Mo 0.2 The negative electrode sheet prepared by Cr3O4 maintained its overall morphology and structural integrity after charge-discharge cycles, exhibiting only moderate and uniform volume expansion. This indicates that the high-entropy oxide (Cr3O4) used in this process... 0.2 Fe 0.2 Ni 0.2 Mn 0.2 Mo0.2 The negative electrode prepared by 3O4 effectively releases internal stress through controllable self-expansion, thereby avoiding severe pulverization or interface peeling with the solid electrolyte, as is the case with silicon-based materials. This is crucial for maintaining long-term stable solid-solid interface contact in all-solid batteries.

[0055] This invention is the first to apply high-entropy oxide composite anode material to the anode of all-solid-state lithium batteries. By utilizing the unique "cocktail effect" and lattice distortion effect of high-entropy oxides, it exhibits excellent interface stability and cycle life, providing an innovative material solution for solving the key technical challenges of anodes in all-solid-state batteries.

[0056] In preparing high-entropy oxide composite anode materials according to this invention, if any one of the five elements Cr, Fe, Ni, Mn, and Mo is missing, and the remaining four elements are combined with oxygen to form high-entropy oxides with rock salt or spinel structures, such as (CrFeNiMn)3O4 and (CrFeNiMo)3O4, etc., these quaternary high-entropy systems are the most direct and easily implemented variants under the core concept of this invention.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical methods of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical methods of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical methods to deviate from the spirit and scope of the technical methods of the present invention.

Claims

1. A high-entropy oxide composite anode material, characterized in that, The high-entropy oxide composite anode material comprises: a metal element and an oxygen element; the metal element is at least five of the elements selected from chromium, iron, nickel, manganese, molybdenum, copper, and cerium; the molar ratio of the metal element to the oxygen element is 3:4; and the high-entropy oxide composite anode material has a spinel structure.

2. The high-entropy oxide composite anode material according to claim 1, characterized in that, The metal elements are chromium, iron, nickel, manganese and molybdenum in a molar ratio of 1:1:1:1:1; the metal elements are chromium, iron, nickel, manganese and copper in a molar ratio of 1:1:1:1:1; the metal elements are chromium, iron, nickel, manganese, molybdenum and cerium in a molar ratio of 1:1:1:1:1:

1.

3. The high-entropy oxide composite anode material according to claim 1, characterized in that, The high-entropy oxide composite anode material consists of submicron-sized particles; the high-entropy oxide composite anode material is prepared by ball milling-sintering method.

4. A method for preparing a high-entropy oxide composite anode material, characterized in that, The preparation of a high-entropy oxide composite anode material as described in any one of claims 1-3 includes the following steps: S1. Mix the metal oxides to obtain mixed metal oxides, add solvent and perform high-energy ball milling to obtain ball mill slurry; S2. Dry and sieve the ball mill slurry to obtain a uniformly mixed precursor powder; S3. The precursor powder is sintered in an air atmosphere to obtain a high-entropy oxide composite anode material.

5. The method for preparing a high-entropy oxide composite anode material according to claim 4, characterized in that, The solvent is anhydrous alcohol.

6. The method for preparing a high-entropy oxide composite anode material according to claim 5, characterized in that, The mass-to-volume ratio of the mixed metal oxide and anhydrous ethanol in S1 is (5-6) g: 3 mL; the mixed metal oxide is at least five of the following: chromium oxide, iron oxide, nickel oxide, manganese oxide, molybdenum oxide, copper oxide, and cerium oxide.

7. The method for preparing a high-entropy oxide composite anode material according to claim 4, characterized in that, The high-energy ball mill in S1 operates at a speed of 800 r / min, alternating between forward and reverse rotation, with a total effective ball milling time of 2 hours.

8. The method for preparing a high-entropy oxide composite anode material according to claim 4, characterized in that, The drying temperature in S2 is 80℃, and the drying time is 10 hours.

9. The method for preparing a high-entropy oxide composite anode material according to claim 4, characterized in that, In S3, sintering involves heating to 800℃-1000℃ at a rate of 5℃ / min and holding at that temperature for 10 hours.

10. An application of a high-entropy oxide composite anode material, characterized in that, The high-entropy oxide composite anode material according to any one of claims 1-3 is applied to the anode of an all-solid-state lithium battery.

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