High-entropy oxide negative electrode material with porous structure, preparation method and application

Abstract

The invention relates to the technical field of high-entropy materials, in particular to a high-entropy oxide negative electrode material with a porous structure, a preparation method and application, the preparation method comprises the following steps: S1, adding Fe (NO3) 3.9 H2O, Ni (NO3) 2.6 H2O, Cr (NO3) 3.9 H2O, Mn (NO3) 2, Cu (NO3) 2 and Al (NO3) 3.9 H2O into deionized water, and uniformly stirring at room temperature to obtain a mixed solution; s2, adding the modified fuel into the mixed solution, uniformly stirring at 60-80 DEG C, and adjusting the pH value to 6-8 to obtain brown sol; and S3, drying the brown sol obtained in the step S2 in a drying oven to obtain viscous gel, putting the gel in a muffle furnace, and carrying out heat preservation at 600-800 DEG C for 20-120 minutes to finally obtain the porous (FeNiCrMnCuAl) 3O4 high-entropy oxide powder material. By regulating and controlling the element composition of the high-entropy oxide, the high-entropy oxide which is diversified in chemical composition and keeps a spinel structure is constructed, so that the electrochemical performance of the high-entropy oxide is regulated and controlled, and the requirements of specific application scenes are met.

Description

Technical Field

[0001] This invention relates to the field of high-entropy materials technology, specifically to a high-entropy oxide anode material with a porous structure, its preparation method, and its application. Background Technology

[0002] With the growing global demand for renewable energy and sustainable power systems, the research and development of advanced energy storage technologies has become crucial. Lithium-ion batteries (LIBs), due to their high energy density, long cycle life, and relatively low environmental impact, have become a core technology in this transformation. Battery performance largely depends on the anode material, which directly determines the battery's capacity and efficiency. Traditionally, graphite has been widely used as an anode material due to its stability and cost-effectiveness. However, graphite's theoretical capacity is only 372 mAh / g, a limitation that significantly reduces the energy density of lithium-ion batteries, restricting their application in high-performance applications such as electric vehicles and large-scale grid energy storage.

[0003] To overcome this bottleneck, researchers have begun exploring alternative anode materials with higher capacity and better electrochemical performance. Transition metal oxides (TMOs) have attracted considerable attention due to their theoretical capacities typically exceeding 600 mAh / g. Despite their potential, TMOs still face significant challenges, including poor cycling stability and low conductivity. These problems primarily stem from the significant volume changes during lithium-ion insertion and extraction, as well as the slow ion and electron transport kinetics, which lead to performance degradation over time.

[0004] High entropy oxides (HEOs) offer a compelling solution to these challenges. HEOs are a novel class of materials characterized by a single-phase solid solution comprising five or more metallic elements in near equimolar ratios, achieving stability through high configurational entropy. This unique structure endows HEOs with superior properties, including excellent structural stability, tunable electronic characteristics, and resistance to degradation under harsh conditions. These properties make HEOs particularly suitable for energy storage applications, especially in scenarios requiring long-lasting and stable performance.

[0005] Currently, the mainstream preparation of high-entropy oxides still mainly relies on traditional high-temperature sintering processes (such as holding at around 1100℃ for 12-18 hours, see MM Kandage, J. Mater. Sci. 2024 59:16618-16628). This method has significant bottlenecks: the slow heating rate of the equipment (≈5℃ / min) causes the material to undergo a long low-temperature zone before reaching the target temperature, resulting in a large amount of volatile elements escaping and a sharp drop in raw material utilization; at the same time, the low upper temperature limit (≤1200℃) restricts the reaction kinetics, forcing a further extension of the sintering time. This long-term high-temperature process is not only energy-intensive, but also induces grain coarsening and pore structure collapse, making it difficult to achieve both morphology and performance. Specifically, in existing high-temperature solid-state methods (such as 1100℃ / 12h), the slow diffusion process ((Dt) 1 / 2 (≈200nm) will cause Al 3+ Migrating to grain boundaries and precipitating Al2O3 impurities or iron-aluminum spinel disrupts material homogeneity. These energy-efficiency bottlenecks and insufficient structural controllability make traditional methods insufficient to meet the requirements of high-entropy oxides for efficient, energy-saving, and large-scale preparation and their application in high-performance lithium-ion batteries. Therefore, there is an urgent need to develop new methods that can significantly improve synthesis efficiency while maintaining excellent electrochemical performance. The breakthrough approach adopted in this application is a fuel-rich combustion synthesis (glycine / metal = 1.5-3:1) combined with rapid heating: its extremely fast heating rate of 50℃ / min and adiabatic flame temperature (Tad) of up to about 1500K can form local micro-regions of melting at >1500℃ within tens of milliseconds. This melt is sufficient to dissolve high-melting-point Al2O3; while the short holding time effectively inhibits Al2O3 precipitation. 3+ Diffusion to the outside of the crystal lattice prevents precipitation at grain boundaries. It is noteworthy that in conventional solution combustion methods, the fuel / metal ratio is typically low (1:0.5-1.5), insufficient for energy release and temperature peaks to achieve single-phase solid solution in a high-entropy system. The fuel-rich ratio (1:1.5-3) used in this application is key to achieving this "high-temperature melting-rapid cooling and phase fixation" mechanism and obtaining a pure-phase spinel structure. This critical parameter window of "low temperature-short time-rapid cooling" is impossible to achieve under traditional slow heating conditions (5℃ / min, process time >3h), because Al2O3 inevitably precipitates prematurely during the slow heating stage. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a high-entropy oxide anode material with a porous structure, its preparation method, and its applications. The present invention employs a convenient, practical, and easily promoted preparation method—the solution combustion method—to obtain a spinel-type high-entropy oxide nanocrystalline powder material with a high specific surface area and a porous structure, exhibiting excellent high-current charge-discharge characteristics.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A method for preparing a high-entropy oxide anode material with a porous structure includes the following preparation steps: S1. By mass, add 1.8-2 parts Fe(NO3)3·9H2O, 1.3-1.5 parts Ni(NO3)2·6H2O, 1.8-2 parts Cr(NO3)3·9H2O, 0.8-1 parts Mn(NO3)2, 0.9-1.1 parts Cu(NO3)2 and 1.8-2 parts Al(NO3)3·9H2O to 20-25 parts deionized water, and stir evenly at room temperature to obtain a mixed solution; S2. Add 4-7 parts of the modified fuel to the mixed solution obtained in step S1, stir evenly at 60-80℃, adjust the pH to 6-8, and obtain a brown sol. S3. The brown sol obtained in step S2 is dried in an oven to obtain a viscous gel. The gel is then placed in a muffle furnace and kept at 600-800℃ for 20-120 min to finally obtain a porous (FeNiCrMnCuAl)3O4 high-entropy oxide powder material. The preparation of modified fuels includes the following steps: S21. By mass, add 0.1-0.5 parts of carbon nanotubes and 0.2-0.8 parts of polyvinylpyrrolidone to 10-15 parts of deionized water, stir at 500-600 r / min for 20-30 min, and then ultrasonically disperse for 30-40 min to obtain a dispersion. S22. Add 3.6-6.7 parts of glycine and 3-6 parts of modifying agent to the dispersion obtained in step S21, and stir at 400-600 r / min for 40-50 min under water bath conditions at 60-70℃. S23. The mixture obtained in step S22 is left to stand and age at room temperature for 1-2 hours to finally obtain the modified fuel.

[0008] Preferably, the preparation of the modified auxiliary agent includes the following steps: S221. By weight, mix 0.3-0.8 parts of polyethylene glycol-400 and 5-10 parts of deionized water, and stir at a speed of 300-400 r / min for 10-15 min in a water bath to obtain a preliminary mixture; S222. Add 1-2 parts citric acid, 0.5-1.5 parts urea, 0.5-1.5 parts sucrose, 0.5-1.0 parts glucose and 0.2-0.6 parts ammonium nitrate to the preliminary mixture obtained in step S221, and stir for 30-45 minutes in a water bath at 50-60℃ to obtain the secondary mixture. S223. Slowly add 0.1-0.3 parts of hexadecyltrimethylammonium bromide to the mixture obtained in step S222, and continue stirring at a speed of 500-600 r / min for 20-30 min while maintaining a water bath at 50-60℃, to finally obtain the modified auxiliary agent.

[0009] Preferably, ammonia is used as the reagent to adjust the pH in step S2.

[0010] Preferably, the drying temperature of the oven in step S3 is 60-80℃.

[0011] Preferably, the heating rate of the muffle furnace in step S3 is 50°C / min.

[0012] Preferably, the frequency of ultrasonic dispersion in step S21 is 40 kHz.

[0013] Preferably, the water bath temperature in step S221 is 40-50℃.

[0014] Preferably, the stirring speed in step S222 is 500-600 r / min.

[0015] A high-entropy oxide anode material with a porous structure was prepared by the above-described preparation method.

[0016] Application of a high-entropy oxide anode material with a porous structure in lithium-ion batteries.

[0017] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention constructs high-entropy oxides with diverse chemical compositions while maintaining the spinel structure by controlling the elemental composition of high-entropy oxides, thereby controlling their electrochemical performance to meet the needs of specific application scenarios.

[0018] 2. Compared with traditional methods (such as sintering at 1100℃ for 12-18h), the present invention adopts a solution combustion method, which significantly reduces the maximum calcination temperature to below 850℃ (preferably 650-750℃) and greatly shortens the holding time to less than 2 hours (preferably 20-60min), greatly reducing energy consumption and production costs, and effectively suppressing the loss of volatile elements (such as Mn) and excessive grain growth.

[0019] 3. The present invention enables the prepared porous high-entropy oxide anode material to have a high specific surface area and porous structure through the synergistic effect of modified fuel and modified auxiliary agent. This can effectively alleviate the structural damage caused by volume expansion effect, and also facilitate the penetration of electrolyte. Attached Figure Description

[0020] Figure 1 This is a process flow diagram for preparing the high-entropy oxide anode material with a porous structure according to the present invention. Figure 2 The image shows the XRD pattern of the porous (FeNiCrMnCuAl)3O4 high-entropy oxide powder material obtained in Example 1 of this invention. Figure 3 Here are SEM images of the porous (FeNiCrMnCuAl)3O4 high-entropy oxide powder material obtained in Example 1 of this invention. Figure 4 The image shows a TEM image of the porous (FeNiCrMnCuAl)3O4 high-entropy oxide powder material obtained in Example 1 of this invention. Figure 5 This is a charge-discharge performance curve of the porous (FeNiCrMnCuAl)3O4 high-entropy oxide powder material obtained in Example 1 of the present invention; Figure 6 The porous (FeNiCrMnCuAl)3O4 high-entropy oxide powder material obtained in Example 1 of this invention was subjected to a temperature of 200 mA g. -1 Images of 200 charge-discharge cycles at current density; Figure 7 The porous (FeNiCrMnCuAl)3O4 high-entropy oxide powder material obtained in Example 1 of this invention was subjected to a temperature of 1000 mA g. -1 Images of 900 charge-discharge cycles at current density; Figure 8 This is a charge-discharge rate performance curve of the porous (FeNiCrMnCuAl)3O4 high-entropy oxide powder material obtained in Example 1 of the present invention. Figure 9 The image shows the XRD pattern of the porous (FeNiCrMnCuAl)3O4 high-entropy oxide powder material obtained in Comparative Example 1 of this invention. Figure 10 The porous (FeNiCrMnCuAl)3O4 high-entropy oxide powder material obtained in Comparative Example 1 of this invention was subjected to a temperature of 200 mA g. -1 Images of 200 charge-discharge cycles at current density; Figure 11 The image shows the XRD pattern of the porous (FeNiCrMnCuAl)3O4 high-entropy oxide powder material obtained in Comparative Example 2 of this invention. Figure 12 The porous (FeNiCrMnCuAl)3O4 high-entropy oxide powder material obtained in Comparative Example 2 of this invention was subjected to a temperature of 200 mA g. -1 Images of 200 charge-discharge cycles at current density. Detailed Implementation

[0021] The present invention will now be clearly and completely described in conjunction with embodiments thereof. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0022] Please see Figure 1-12 The present invention provides a technical solution: Example 1 A method for preparing a high-entropy oxide anode material with a porous structure: Before preparing high-entropy oxide anode materials with porous structures, modification auxiliaries and modified fuels are first prepared: The preparation of the modified auxiliary agent includes the following steps: S221. Mix 0.3g polyethylene glycol-400 and 5g deionized water, and stir at 300r / min for 10min in a 40℃ water bath to obtain a preliminary mixture; S222. Add 1g citric acid, 0.5g urea, 0.5g sucrose, 0.5g glucose and 0.2g ammonium nitrate to the preliminary mixture obtained in step S221, and stir at 500r / min for 30min under 50℃ water bath conditions to obtain the secondary mixture. S223. Slowly add 0.1 g of cetyltrimethylammonium bromide to the mixture obtained in step S222, and continue stirring at 500 r / min for 20 min while maintaining a water bath at 50°C, to finally obtain the modified auxiliary agent.

[0023] The preparation of modified fuels includes the following steps: S21. Add 0.1g carbon nanotubes and 0.2g polyvinylpyrrolidone to 10g deionized water, stir at 500r / min for 20min, and then sonicate at 40kHz for 30min to obtain a dispersion. S22. Add 3.6g glycine and 3g modifier to the dispersion obtained in step S21, and stir at 400r / min for 40min in a water bath at 60℃. S23. The mixture obtained in step S22 is left to stand and age at room temperature for 1 hour to finally obtain the modified fuel.

[0024] S1. Add 1.8g Fe(NO3)3·9H2O, 1.3g Ni(NO3)2·6H2O, 1.8g Cr(NO3)3·9H2O, 0.8g Mn(NO3)2, 0.9g Cu(NO3)2 and 1.8g Al(NO3)3·9H2O to 20g deionized water and stir until homogeneous at room temperature to obtain a mixed solution; S2. Add 4g of modified fuel to the mixed solution obtained in step S1, stir evenly at 60℃, add ammonia water to adjust the pH to 6, and obtain a brown sol. S3. The brown sol obtained in step S2 is dried in an oven at 60°C to obtain a viscous gel. The gel is then placed in a muffle furnace and kept at 600°C for 20 minutes with a heating rate of 50°C / min to finally obtain a porous (FeNiCrMnCuAl)3O4 high-entropy oxide powder material.

[0025] Example 2 A method for preparing a high-entropy oxide anode material with a porous structure: Before preparing high-entropy oxide anode materials with porous structures, modification auxiliaries and modified fuels are first prepared: The preparation of the modified auxiliary agent includes the following steps: S221. Mix 0.8g of polyethylene glycol-400 and 10g of deionized water, and stir at 400r / min for 15min in a 50℃ water bath to obtain a preliminary mixture; S222. Add 2g citric acid, 1.5g urea, 1.5g sucrose, 1.0g glucose and 0.6g ammonium nitrate to the preliminary mixture obtained in step S221, and stir at 600r / min for 45min under 60℃ water bath conditions to obtain the secondary mixture. S223. Slowly add 0.3g of cetyltrimethylammonium bromide to the mixture obtained in step S222, and continue stirring at 600r / min for 30min while maintaining a water bath at 60℃, to finally obtain the modified auxiliary agent.

[0026] The preparation of modified fuels includes the following steps: S21. Add 0.5g carbon nanotubes and 0.8g polyvinylpyrrolidone to 15g deionized water, stir at 600r / min for 30min, and then sonicate at 40kHz for 40min to obtain a dispersion. S22. Add 6.7g glycine and 3-6g modifier to the dispersion obtained in step S21, and stir at 600r / min for 40-50min in a water bath at 70℃. S23. The mixture obtained in step S22 is left to stand and age at room temperature for 2 hours to finally obtain the modified fuel.

[0027] S1. Add 2g Fe(NO3)3·9H2O, 1.5g Ni(NO3)2·6H2O, 2g Cr(NO3)3·9H2O, 1g Mn(NO3)2, 1.1g Cu(NO3)2 and 2g Al(NO3)3·9H2O to 25g deionized water and stir until homogeneous at room temperature to obtain a mixed solution; S2. Add 7g of modified fuel to the mixed solution obtained in step S1, stir evenly at 80℃, add ammonia water to adjust the pH to 8, and obtain a brown sol. S3. The brown sol obtained in step S2 is dried in an oven at 80°C to obtain a viscous gel. The gel is then placed in a muffle furnace and kept at 800°C for 120 min with a heating rate of 50°C / min to finally obtain a porous (FeNiCrMnCuAl)3O4 high-entropy oxide powder material.

[0028] Example 3 A method for preparing a high-entropy oxide anode material with a porous structure: Before preparing high-entropy oxide anode materials with porous structures, modification auxiliaries and modified fuels are first prepared: The preparation of the modified auxiliary agent includes the following steps: S221. Mix 0.4g of polyethylene glycol-400 and 6g of deionized water, and stir at 320r / min for 11min in a 42℃ water bath to obtain a preliminary mixture; S222. Add 1.2g citric acid, 0.6g urea, 0.6g sucrose, 0.6g glucose and 0.3g ammonium nitrate to the preliminary mixture obtained in step S221, and stir at 520r / min for 35min under 52℃ water bath conditions to obtain the secondary mixture. S223. Slowly add 0.15g of cetyltrimethylammonium bromide to the mixture obtained in step S222, and continue stirring at 520r / min for 22min while maintaining a water bath at 52℃, to finally obtain the modified auxiliary agent.

[0029] The preparation of modified fuels includes the following steps: S21. Add 0.2g carbon nanotubes and 0.3g polyvinylpyrrolidone to 11g deionized water, stir at 520r / min for 22min, and then sonicate at 40kHz for 32min to obtain a dispersion. S22. Add 4.1g glycine and 4g modifier to the dispersion obtained in step S21, and stir at 450r / min for 42min in a water bath at 62℃. S23. The mixture obtained in step S22 is left to stand and age at room temperature for 1.5 hours to finally obtain the modified fuel.

[0030] S1. Add 1.85g Fe(NO3)3·9H2O, 1.35g Ni(NO3)2·6H2O, 1.85g Cr(NO3)3·9H2O, 0.85g Mn(NO3)2, 0.96g Cu(NO3)2 and 1.85g Al(NO3)3·9H2O to 21g deionized water and stir until homogeneous at room temperature to obtain a mixed solution; S2. Add 5g of modified fuel to the mixed solution obtained in step S1, stir evenly at 65℃, add ammonia water to adjust the pH to 6.5, and obtain a brown sol. S3. The brown sol obtained in step S2 is dried in an oven at 65°C to obtain a viscous gel. The gel is then placed in a muffle furnace and kept at 650°C for 50 min with a heating rate of 50°C / min to finally obtain a porous (FeNiCrMnCuAl)3O4 high-entropy oxide powder material.

[0031] Example 4 A method for preparing a high-entropy oxide anode material with a porous structure: Before preparing high-entropy oxide anode materials with porous structures, modification auxiliaries and modified fuels are first prepared: The preparation of the modified auxiliary agent includes the following steps: S221. Mix 0.7g polyethylene glycol-400 and 8g deionized water, and stir at 380r / min for 14min in a 48℃ water bath to obtain a preliminary mixture; S222. Add 1.8g citric acid, 1.3g urea, 1.3g sucrose, 0.8g glucose and 0.5g ammonium nitrate to the preliminary mixture obtained in step S221, and stir at 580r / min for 41min in a 57℃ water bath to obtain the secondary mixture. S223. Slowly add 0.25g of cetyltrimethylammonium bromide to the mixture obtained in step S222, and continue stirring at 580r / min for 27min while maintaining a water bath at 58℃, to finally obtain the modified auxiliary agent.

[0032] The preparation of modified fuels includes the following steps: S21. Add 0.4g carbon nanotubes and 0.7g polyvinylpyrrolidone to 14g deionized water, stir at 580r / min for 28min, and then sonicate at 40kHz for 37min to obtain a dispersion. S22. Add 5.4g glycine and 5g modifier to the dispersion obtained in step S21, and stir at 550r / min for 47min in a water bath at 68℃. S23. The mixture obtained in step S22 is left to stand and age at room temperature for 1.5 hours to finally obtain the modified fuel.

[0033] S1. Add 1.92g Fe(NO3)3·9H2O, 1.45g Ni(NO3)2·6H2O, 1.93g Cr(NO3)3·9H2O, 0.94g Mn(NO3)2, 1.05g Cu(NO3)2 and 1.95g Al(NO3)3·9H2O to 24g deionized water and stir until homogeneous at room temperature to obtain a mixed solution; S2. Add 6g of modified fuel to the mixed solution obtained in step S1, stir evenly at 75℃, add ammonia water to adjust the pH to 7, and obtain a brown sol. S3. The brown sol obtained in step S2 is dried in an oven at 75°C to obtain a viscous gel. The gel is then placed in a muffle furnace and kept at 750°C for 80 min with a heating rate of 50°C / min to finally obtain a porous (FeNiCrMnCuAl)3O4 high-entropy oxide powder material.

[0034] Comparative Example 1 The only difference between Comparative Example 1 and Example 1 is that the modified fuel in this comparative example is replaced with glycine; the other steps are exactly the same in Comparative Example 1 and Example 1.

[0035] Comparative Example 2 This comparative example uses the traditional high-temperature solid-state method to prepare the high-entropy oxide anode material of the present invention. Its chemical composition is (FeNiCrMnCuAl)3O4: metal oxides are weighed and mixed according to the molecular formula, specifically: Fe2O3 (0.3992 g), NiO (0.3734 g), Cr2O3 (0.3547 g), MnO (0.39775 g), CuO (0.3734 g), and Al2O3 (0.2549 g). The mixed oxide powders are placed in a mortar and ground for 1 h. The uniformly ground powder is placed in a corundum crucible and heated to 1100℃ in a muffle furnace. The temperature is increased at a rate of 5℃ / min and held for 12 h. Then, it is naturally cooled to room temperature to obtain (FeNiCrMnCuAl)3O4 high-entropy oxide powder.

[0036] Performance testing: According to the appendix Figure 2 - Appendix Figure 8 Performance testing of the porous (FeNiCrMnCuAl)3O4 high-entropy oxide powder material obtained in Example 1 showed that it had a spinel-type crystal structure and a specific surface area of ​​14.08 m². 2 A porous (FeNiCrMnCuAl)3O4 high-entropy oxide powder material with an average pore size of 29.46 nm and a BET adsorption capacity of 1121.67 mAh g / g. -1 , at 200 mA g -1 After 200 cycles at a current density, the reversible specific capacity stabilized at 661.1 mAh g. -1 At 1000mA g -1 After 900 cycles at a current density, the reversible specific capacity stabilized at 461.8 mAh g⁻¹. -1 Furthermore, it exhibits good rate performance, especially when the current density returns to 100 mA g. -1 The capacity is 857.715 mAh g. -1 The capacity retention rate was 88.5%; meanwhile, from the attached Figure 5 It is evident that after more than 60 cycles, the specific capacity gradually increases.

[0037] By examining the appendix Figure 9 and attached Figure 10 Performance testing of the porous (FeNiCrMnCuAl)3O4 high-entropy oxide powder material obtained in Comparative Example 1 revealed two impurity peaks at 35.9° and 44.5° that were not spinel-like. Analysis showed these peaks belonged to the second phase, Fe+2Al2O4. The formation of this second phase is attributed to the replacement of modified fuel with glycine during combustion, where the energy release and temperature peak were insufficient to achieve single-phase solid solution of Al in the high-entropy system. This comparative example was tested at 200 mA g. -1 The capacity at the current density is a reversible specific capacity that remains stable at 467.4 mAh g⁻¹. -1 The size is smaller than in Example 1 because the fuel is lower, and its energy release and temperature peak are insufficient to achieve solid solution of Al in a high-entropy system, forming a Fe+2Al2O4 second phase that hinders the Li... + The transport path is disrupted, and side reactions are triggered during lithiation / delithiation, leading to performance degradation.

[0038] By examining the appendix Figure 11 and attached Figure 12Performance testing of the porous (FeNiCrMnCuAl)3O4 high-entropy oxide powder material obtained in Comparative Example 2 revealed two impurity peaks at 30.8° and 35.9° that were not spinel-like. Analysis showed these peaks belonged to the second phase, Fe+2Al2O4. The formation of this second phase is attributed to the precipitation of Al elements during the prolonged heat treatment process. This comparative example was tested at 200 mA g... -1 The capacity at current density is reversible, and the specific capacity remains stable at 474 mAh g. -1 Compared to Example 1, the values ​​are smaller. This is because the traditional high-temperature solid-state method, with its excessively long holding time, causes aluminum to penetrate the spinel lattice and form a second phase, hindering the formation of Li. + The transport path is disrupted, and side reactions are triggered during lithiation / delithiation, leading to performance degradation.

[0039] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a high-entropy oxide anode material with a porous structure, characterized in that, The preparation steps include the following: S1. By mass, add 1.8-2 parts Fe(NO3)3·9H2O, 1.3-1.5 parts Ni(NO3)2·6H2O, 1.8-2 parts Cr(NO3)3·9H2O, 0.8-1 parts Mn(NO3)2, 0.9-1.1 parts Cu(NO3)2 and 1.8-2 parts Al(NO3)3·9H2O to 20-25 parts deionized water, and stir evenly at room temperature to obtain a mixed solution; S2. Add 4-7 parts of the modified fuel to the mixed solution obtained in step S1, stir evenly at 60-80℃, adjust the pH to 6-8, and obtain a brown sol. S3. The brown sol obtained in step S2 is dried in an oven to obtain a viscous gel. The gel is then placed in a muffle furnace and kept at 600-800℃ for 20-120 min to finally obtain a porous (FeNiCrMnCuAl)3O4 high-entropy oxide powder material. The preparation of the modified fuel includes the following steps: S21. By mass, add 0.1-0.5 parts of carbon nanotubes and 0.2-0.8 parts of polyvinylpyrrolidone to 10-15 parts of deionized water, stir at 500-600 r / min for 20-30 min, and then ultrasonically disperse for 30-40 min to obtain a dispersion. S22. Add 3.6-6.7 parts of glycine and 3-6 parts of modifying agent to the dispersion obtained in step S21, and stir at 400-600 r / min for 40-50 min under water bath conditions at 60-70℃. S23. The mixture obtained in step S22 is left to stand and age at room temperature for 1-2 hours to finally obtain the modified fuel.

2. The method for preparing a high-entropy oxide anode material with a porous structure according to claim 1, characterized in that, The preparation of the modified auxiliary agent includes the following steps: S221. By weight, mix 0.3-0.8 parts of polyethylene glycol-400 and 5-10 parts of deionized water, and stir at a speed of 300-400 r / min for 10-15 min in a water bath to obtain a preliminary mixture; S222. Add 1-2 parts citric acid, 0.5-1.5 parts urea, 0.5-1.5 parts sucrose, 0.5-1.0 parts glucose and 0.2-0.6 parts ammonium nitrate to the preliminary mixture obtained in step S221, and stir for 30-45 minutes in a water bath at 50-60℃ to obtain the mixture of the second step. S223. Slowly add 0.1-0.3 parts of hexadecyltrimethylammonium bromide to the mixture obtained in step S222, and continue stirring at a speed of 500-600 r / min for 20-30 min while maintaining a water bath at 50-60℃, to finally obtain the modified auxiliary agent.

3. The method for preparing a high-entropy oxide anode material with a porous structure according to claim 1, characterized in that, In step S2, ammonia is used as the reagent to adjust the pH.

4. The method for preparing a high-entropy oxide anode material with a porous structure according to claim 1, characterized in that, The drying temperature of the oven in step S3 is 60-80℃.

5. The method for preparing a high-entropy oxide anode material with a porous structure according to claim 1, characterized in that, In step S3, the heating rate of the muffle furnace is 50℃ / min.

6. The method for preparing a high-entropy oxide anode material with a porous structure according to claim 1, characterized in that, In step S21, the frequency of ultrasonic dispersion is 40 kHz.

7. The method for preparing a high-entropy oxide anode material with a porous structure according to claim 2, characterized in that, The water bath temperature in step S221 is 40-50℃.

8. The method for preparing a high-entropy oxide anode material with a porous structure according to claim 2, characterized in that, The stirring speed in step S222 is 500-600 r / min.

9. A high-entropy oxide anode material with a porous structure, characterized in that, It is prepared by the preparation method described in any one of claims 1-8.

10. The application of a high-entropy oxide anode material with a porous structure according to claim 9 in a lithium-ion battery.

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