Cyclic stable spinel phase high-entropy oxide negative electrode material and preparation and application thereof
By introducing elements of different valence states into lithium-ion batteries to regulate spinel-type high-entropy oxides and forming a single-phase spinel structure, the problems of low conductivity and poor cycle performance of existing lithium-ion battery anode materials are solved, achieving high specific capacity and excellent cycle stability and rate performance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-16
- Publication Date
- 2026-03-27
AI Technical Summary
Existing lithium-ion battery anode materials, such as graphite and transition metal oxides, suffer from low conductivity, weak ion diffusion, large volume expansion, and poor cycle performance, making it difficult to meet the requirements of high-performance lithium-ion batteries.
High-entropy oxide (Cr0.2Mn0.2Fe0.2Co0.2)3O4 was used as the negative electrode material for lithium-ion batteries. By introducing elements with different valence states, the structure of the spinel-type high-entropy oxide was controlled to form a single-phase spinel structure, thereby improving the electrochemical performance.
It achieves high specific capacity, excellent cycle stability and rate performance, significantly improving the electrochemical performance of lithium-ion batteries.
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Figure CN121748368A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of lithium-ion battery technology, and particularly relates to a cycle-stable spinel phase high-entropy oxide anode material and its preparation and application. Background Technology
[0002] With the rapid development of energy storage devices, lithium-ion batteries are placing higher demands on the energy density and power density of electrode materials. Currently, the theoretical capacity of commercially available graphite anodes is only 372 mAh·g. -1 Traditional transition metal oxides (TMOs) are increasingly unable to meet the high-performance requirements of lithium-ion batteries. Due to their high specific capacity, TMOs have gained widespread attention in the field of lithium-ion battery anode materials. However, these materials suffer from low conductivity, weak ion diffusion, and significant volume expansion during charge and discharge, ultimately leading to poor electrochemical performance. These defects are the main obstacles to their practical application as anode materials. High entropy oxides (HEOs), compared to traditional TMOs, have become a research focus due to their tunable elemental composition, excellent thermodynamic and kinetic stability, and entropy stabilization effect. However, HEO anode materials suffer from drawbacks such as low intrinsic conductivity, poor cycle performance, and poor rate performance. Summary of the Invention
[0003] To address the aforementioned problems, this invention provides a cycle-stable spinel-phase high-entropy oxide anode material, its preparation, and its application in lithium batteries. By introducing elements of different valence states, the spinel-type medium-entropy oxide (Cr) is controlled... 0.2 Mn 0.2 Fe 0.2 Co 0.2 By using 3O4, a high-entropy oxide with a spinel single phase was prepared, thereby improving its performance in lithium-ion batteries.
[0004] The spinel phase high-entropy oxide (Cr) of the present invention 0.2 Mn 0.2 Fe 0.2 Co 0.2 M 0.2 3O4 has a spinel single-phase structure, composed of equimolar amounts of the metallic elements Cr, Mn, Fe, Co, and M, where M can be any one of Li, Na, Mg, Zn, Cu, or Al; its first-cycle charge specific capacity reaches 638.8 mAh·g. -1 After 100 cycles, the charging specific capacity is 570.98 mAh·g. -1 The capacity retention rate was 89.38%.
[0005] The method for preparing spinel phase high-entropy oxide of the present invention includes the following: mixing oxides of metal elements Cr, Mn, Fe, Co and M in equimolar ratio, ball milling and then calcining to obtain spinel phase high-entropy oxide;
[0006] The preparation method includes the following specific steps: One of the following powders, Li₂O, Na₂O, MgO, ZnO, CuO, and Al₂O₃, is mixed with Cr₂O₃, Mn₂O₃, Fe₂O₃, and Co₃O₄ powders in an equimolar ratio of the metal elements. After ball milling, the mixture is calcined at 800℃-1200℃ for 4-18 hours. After furnace cooling, a spinel-phase high-entropy oxide is obtained.
[0007] The preferred roasting temperature is 900℃ and the roasting time is 12h;
[0008] The ball milling process included the following conditions: a ball-to-material ratio of 10:1, the use of zirconia grinding beads with diameters of 1 cm and 0.6 cm, the addition of ethanol as the grinding medium, a grinding speed of 300 rpm, and a grinding time of 3 h; after ball milling, the material was dried at 70 °C and then calcined, with the temperature increased to the calcination temperature at a rate of 5 °C / min.
[0009] The spinel-phase high-entropy oxide of the present invention can be used as a negative electrode material for lithium-ion batteries. Using the spinel-phase high-entropy oxide as the active material, the active material, conductive agent, and binder are made into a slurry, which is coated on a copper foil current collector and dried to obtain an electrode sheet. The working electrode of the electrode sheet, the lithium metal sheet counter electrode, the separator, and the electrolyte are encapsulated to obtain a lithium-ion battery.
[0010] The application includes the following specific details: the conductive agent is superconducting carbon black, the binder is polyvinylidene fluoride, the mass ratio of active material, conductive agent and binder is 7:2:1, N-methylpyrrolidone is added as a dispersant, and after thorough grinding, a uniform slurry is prepared; the slurry is uniformly coated on a copper foil current collector, dried under vacuum at 120℃ for 8 hours, and then punched to obtain a circular electrode sheet with a diameter of 1cm;
[0011] Assembly was carried out in a glove box where the water pressure and oxygen partial pressure were both no higher than 0.1 ppm. Celgard 2400 microporous membrane was used as the separator, and lithium hexafluorophosphate solution (containing ethylene carbonate / methyl ethyl carbonate / diethyl carbonate in a volume ratio of 1:1:1) was used as the electrolyte. After encapsulation, a coin cell lithium-ion battery was obtained.
[0012] Compared with existing spinels, the advantages of this invention are as follows:
[0013] This invention employs a high-temperature solid-state method, using entropy oxides (Cr) in the quaternary spinel phase. 0.2 Mn 0.2 Fe 0.2 Co0.2 Based on 3O4, this study systematically investigated the structure-activity relationship between phase composition and electrochemical performance, and the regulatory effect of cation valence on material structure and properties, by introducing equimolar ratios of cations with different valence states (the fifth component, ranging from monovalent to pentavalent). The results showed that the combination of multiple valence cations achieves charge balance and directly relates to the phase composition of the material. A specific valence ratio is a key condition for the formation of a single spinel phase. The introduction of low-valence cations can effectively regulate the crystal structure through charge compensation mechanisms (such as the formation of oxygen vacancies). Different valence cations (such as Co...) can also influence the material's structure and properties. 2+ Cr 3+ Fe 3+ (e.g., etc.) stably occupy the tetrahedral and octahedral sites in the spinel structure, forming a structurally stable high-entropy oxide. This microstructural change significantly improves the electrochemical performance of the electrode material.
[0014] By introducing metal elements with different valence states, a charge compensation mechanism is effectively triggered, generating an appropriate amount of oxygen vacancies, thereby optimizing the electronic structure of the material and significantly improving its electrochemical performance as a battery anode. A stable phase composition dominated by a single spinel phase was achieved, demonstrating that multiple cations can form a stable structure under specific valence ratios, providing an important basis for the composition design of high-entropy oxides. Using a solid-state method, precise control of ball milling and calcination processes ensured uniform product composition, good crystallinity, stable material structure, and consistent performance. The process is simple and mature, parameters are easy to control, equipment requirements are low, and reproducibility is good, which is conducive to the large-scale preparation of materials. The various spinel-phase high-entropy oxides provided by this invention are novel compositions, and no literature currently discloses the formulation of these compositions; moreover, the high-entropy oxides prepared by this invention exhibit excellent specific capacity, rate performance, and cycle stability when applied to lithium-ion battery electrode materials. Attached Figure Description
[0015] Figure 1 X-ray diffraction patterns of the spinel phase oxides prepared in each embodiment and comparative example.
[0016] Figure 2 The spinel phase oxides prepared for Examples 1, 2 and Comparative Example 1 were subjected to a current density of 0.1 A·g -1 The following is a graph showing the cyclic performance.
[0017] Figure 3 The rate performance diagrams for the spinel phase oxides prepared in Examples 1, 2 and Comparative Example 1 at different current densities are shown. Detailed Implementation
[0018] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments and accompanying drawings. It should be noted that the embodiments described in this invention are only for further explanation and illustration, and not for limiting their application scope. Based on this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the protection scope of this invention.
[0019] In this embodiment, the planetary ball mill model is XQM-0.4A, manufactured by Changsha Tianchuang Powder Technology Co., Ltd.; the purity of each oxide raw material is ≥97%, and all reagents are purchased from Aladdin Chemical Reagent Co., Ltd.
[0020] Example 1
[0021] The spinel-phase high-entropy oxide of this embodiment contains equimolar ratios of the metallic elements Cr, Mn, Fe, and Co.
[0022] Cr2O3, Mn2O3, Fe2O3, and Co3O4 powders were weighed according to the equimolar ratio of the metal elements and placed in a polytetrafluoroethylene ball mill jar. An appropriate amount of ethanol was added, and the mixture was ball-milled for 3 hours at 300 rpm using zirconium dioxide grinding beads (large beads with a diameter of 1 cm, small beads with a diameter of 0.6 cm, and a ball-to-powder ratio of 10:1) in a planetary ball mill to obtain a homogeneous slurry. The obtained slurry was dried overnight in a 70℃ oven and then transferred to an alumina crucible. It was then calcined in a muffle furnace at a temperature of 5℃ / min to 900℃ and held for 12 hours. After furnace cooling, the final product, spinel-phase high-entropy oxide lithium-ion battery anode material (Cr2O3), was obtained. 0.2 Mn 0.2 Fe 0.2 Co 0.2 )3O4.
[0023] Figure 1 The 4M in the image is the XRD pattern of the product. Comparison with the standard card JCPDS:34-0140 for FeCr2O4 spinel confirms the successful synthesis of the target single-phase spinel structure.
[0024] Example 2
[0025] The spinel-phase high-entropy oxide of this embodiment contains equimolar ratios of the metallic elements Cr, Mn, Fe, Co and Al.
[0026] Cr2O3, Mn2O3, Fe2O3, Co3O4, and Al2O3 powders were weighed according to the equimolar ratio of the metal elements and placed in a polytetrafluoroethylene ball mill jar. An appropriate amount of ethanol was added, and the mixture was ball-milled for 3 hours at 300 rpm using zirconium dioxide grinding beads (large beads with a diameter of 1 cm, small beads with a diameter of 0.6 cm, and a ball-to-material ratio of 10:1) in a planetary ball mill to obtain a homogeneous slurry. The obtained slurry was dried overnight in a 70℃ oven and then transferred to an alumina crucible. It was then calcined in a muffle furnace at a temperature of 5℃ / min to 900℃ and held for 12 hours. After furnace cooling, the final product, spinel-phase high-entropy oxide lithium-ion battery anode material (Cr2O3), was obtained. 0.2 Mn 0.2 Fe 0.2 Co 0.2 Al 0.2 )3O4.
[0027] Figure 1 The 4M-Al in the image is the XRD pattern of the product. Comparison with the standard card JCPDS:34-0140 for iron-chromium spinel FeCr2O4 confirms the successful synthesis of the target single-phase spinel structure.
[0028] Example 3
[0029] The spinel-phase high-entropy oxide of this embodiment contains equimolar ratios of the metallic elements Cr, Mn, Fe, Co and Li.
[0030] Cr2O3, Mn2O3, Fe2O3, Co3O4, and Li2O powders were weighed according to the equimolar ratio of the metal elements and placed in a polytetrafluoroethylene ball mill jar. An appropriate amount of ethanol was added, and the mixture was ball-milled for 3 hours at 300 rpm using zirconium dioxide grinding beads (large beads with a diameter of 1 cm, small beads with a diameter of 0.6 cm, and a ball-to-material ratio of 10:1) in a planetary ball mill to obtain a homogeneous slurry. The obtained slurry was dried overnight in a 70℃ oven and then transferred to an alumina crucible. It was then calcined in a muffle furnace at a temperature of 5℃ / min to 900℃ and held for 12 hours. After furnace cooling, the final product, spinel-phase high-entropy oxide lithium-ion battery anode material (Cr2O3), was obtained. 0.2 Mn 0.2 Fe 0.2 Co 0.2 Li 0.2 )3O4.
[0031] Figure 1 The 4M-Li XRD pattern of the product was compared with the standard card JCPDS:34-0140 for FeCr2O4 spinel, confirming the successful synthesis of the target single-phase spinel structure.
[0032] Example 4
[0033] The spinel-phase high-entropy oxide of this embodiment contains equimolar ratios of the metallic elements Cr, Mn, Fe, Co, and Na.
[0034] Cr2O3, Mn2O3, Fe2O3, Co3O4, and Na2O powders were weighed according to the equimolar ratio of the metal elements and placed in a polytetrafluoroethylene ball mill jar. An appropriate amount of ethanol was added, and the mixture was ball-milled for 3 hours at 300 rpm using zirconium dioxide grinding beads (large beads with a diameter of 1 cm, small beads with a diameter of 0.6 cm, and a ball-to-powder ratio of 10:1) in a planetary ball mill to obtain a homogeneous slurry. The obtained slurry was dried overnight in a 70℃ oven and then transferred to an alumina crucible. It was then calcined in a muffle furnace at a temperature of 900℃ / min and held at that temperature for 12 hours. After furnace cooling, the final product, spinel-phase high-entropy oxide lithium-ion battery anode material (Cr2O3), was obtained. 0.2 Mn 0.2 Fe 0.2 Co 0.2 Na 0.2 )3O4.
[0035] Figure 1 The 4M-Na XRD pattern of the product was compared with the standard card JCPDS:34-0140 for FeCr2O4 spinel, confirming the successful synthesis of the target single-phase spinel structure.
[0036] Example 5
[0037] The spinel-phase high-entropy oxide of this embodiment contains equimolar ratios of the metallic elements Cr, Mn, Fe, Co, and Zn.
[0038] Cr2O3, Mn2O3, Fe2O3, Co3O4, and ZnO powders were weighed according to the equimolar ratio of the metal elements and placed in a polytetrafluoroethylene ball mill jar. An appropriate amount of ethanol was added, and the mixture was ball-milled for 3 hours at 300 rpm using zirconium dioxide grinding beads (large beads with a diameter of 1 cm, small beads with a diameter of 0.6 cm, and a ball-to-powder ratio of 10:1) in a planetary ball mill to obtain a homogeneous slurry. The obtained slurry was dried overnight in a 70℃ oven and then transferred to an alumina crucible. It was then calcined in a muffle furnace at a temperature of 5℃ / min to 900℃ and held for 12 hours. After furnace cooling, the final product, spinel-phase high-entropy oxide lithium-ion battery anode material (Cr2O3), was obtained. 0.2 Mn 0.2 Fe 0.2 Co 0.2 Zn 0.2 )3O4.
[0039] Figure 1 The XRD pattern of the product is shown in 4M-Zn. Comparison with the standard card JCPDS:34-0140 of FeCr2O4 spinel confirms the successful synthesis of the target single-phase spinel structure.
[0040] Example 6
[0041] The spinel-phase high-entropy oxide of this embodiment contains equimolar ratios of the metallic elements Cr, Mn, Fe, Co, and Cu.
[0042] Cr2O3, Mn2O3, Fe2O3, Co3O4, and CuO powders were weighed according to the equimolar ratio of the metal elements and placed in a polytetrafluoroethylene ball mill jar. An appropriate amount of ethanol was added, and the mixture was ball-milled for 3 hours at 300 rpm using zirconium dioxide grinding beads (large beads with a diameter of 1 cm, small beads with a diameter of 0.6 cm, and a ball-to-powder ratio of 10:1) in a planetary ball mill to obtain a homogeneous slurry. The obtained slurry was dried overnight in a 70℃ oven and then transferred to an alumina crucible. It was then calcined in a muffle furnace at a temperature of 900℃ / min and held at that temperature for 12 hours. After furnace cooling, the final product, spinel-phase high-entropy oxide lithium-ion battery anode material (Cr2O3), was obtained. 0.2 Mn 0.2 Fe 0.2 Co 0.2 Cu 0.2 )3O4.
[0043] Figure 1 The XRD pattern of the product, 4M-Cu, was compared with the standard card JCPDS:34-0140 for FeCr2O4 spinel, confirming the successful synthesis of the target single-phase spinel structure.
[0044] Example 7
[0045] The spinel-phase high-entropy oxide of this embodiment contains equimolar ratios of the metallic elements Cr, Mn, Fe, Co, and Mg.
[0046] Cr2O3, Mn2O3, Fe2O3, Co3O4, and MgO powders were weighed according to the equimolar ratio of the metal elements and placed in a polytetrafluoroethylene ball mill jar. An appropriate amount of ethanol was added, and the mixture was ball-milled for 3 hours at 300 rpm using zirconium dioxide grinding beads (large beads with a diameter of 1 cm, small beads with a diameter of 0.6 cm, and a ball-to-powder ratio of 10:1) in a planetary ball mill to obtain a homogeneous slurry. The obtained slurry was dried overnight in a 70℃ oven and then transferred to an alumina crucible. It was then calcined in a muffle furnace at a temperature of 5℃ / min to 900℃ and held for 12 hours. After furnace cooling, the final product, spinel-phase high-entropy oxide lithium-ion battery anode material (Cr2O3), was obtained. 0.2 Mn 0.2 Fe 0.2 Co 0.2 Mg 0.2 )3O4.
[0047] Figure 1The XRD pattern of the product, 4M-Mg, was compared with the standard card JCPDS:34-0140 for FeCr2O4 spinel, confirming the successful synthesis of the target single-phase spinel structure.
[0048] Comparative Example 1
[0049] The oxide material prepared in this comparative example contains equimolar amounts of the metallic elements Cr, Mn, Fe, Co, and Ti.
[0050] Cr2O3, Mn2O3, Fe2O3, Co3O4, and TiO2 powders were weighed according to the equimolar ratio of the metal elements and placed in a polytetrafluoroethylene ball mill jar. An appropriate amount of ethanol was added, and the mixture was ball-milled for 3 hours at 300 rpm using zirconia ball milling beads (large beads with a diameter of 1 cm, small beads with a diameter of 0.6 cm, and a ball-to-powder ratio of 10:1) to obtain a homogeneous slurry. The obtained slurry was dried overnight in a 70℃ oven and then transferred to an alumina crucible. It was then calcined in a muffle furnace at a temperature of 900℃ at a rate of 5℃ / min and held at that temperature for 12 hours. After furnace cooling, the final product was obtained.
[0051] Figure 1 The XRD pattern of the product, 4M-Ti, was compared with the standard card JCPDS:34-0140 for FeCr2O4 spinel, confirming that the target single-phase spinel structure was not formed and a second phase appeared.
[0052] Comparative Example 2
[0053] The oxide material prepared in this comparative example contains equimolar amounts of the metallic elements Cr, Mn, Fe, Co, and Nb.
[0054] Cr2O3, Mn2O3, Fe2O3, Co3O4, and Nb2O5 powders were weighed according to the equimolar ratio of the metal elements and placed in a polytetrafluoroethylene ball mill jar. An appropriate amount of ethanol was added, and the mixture was ball-milled for 3 hours at 300 rpm using zirconia ball milling beads (large beads with a diameter of 1 cm, small beads with a diameter of 0.6 cm, and a ball-to-powder ratio of 10:1) to obtain a homogeneous slurry. The obtained slurry was dried overnight in a 70℃ oven and then transferred to an alumina crucible. It was then calcined in a muffle furnace at a temperature of 900℃ at a rate of 5℃ / min and held at that temperature for 12 hours. After furnace cooling, the final product was obtained.
[0055] Figure 1 The XRD pattern of the product is shown in 4M-Nb. When compared with the standard card JCPDS:34-0140 of FeCr2O4 spinel, a second phase is observed.
[0056] The spinel-phase high-entropy oxide prepared in this invention can be used as an active material for the negative electrode of lithium-ion batteries. Lithium-ion batteries were prepared using the spinel-phase high-entropy oxides prepared in Examples 1 and 2, and the Ti-doped oxide prepared in Comparative Example 1, respectively, as active materials. The active material, superconducting carbon black as a conductive agent, and polyvinylidene fluoride as a binder were mixed in a mass ratio of 7:2:1, with an appropriate amount of N-methylpyrrolidone added as a dispersant. After thorough grinding, a uniform slurry was prepared. This slurry was uniformly coated onto a copper foil current collector and vacuum dried at 120°C for 8 hours. After punching, a circular electrode sheet with a diameter of 1 cm was obtained. Using the prepared electrode sheet as the working electrode, a lithium metal sheet as the counter electrode, a Celgard 2400 microporous membrane as the separator, and injecting a 1 mol / L lithium hexafluorophosphate solution (ethylene carbonate / methyl ethyl carbonate / diethyl carbonate, volume ratio 1:1:1) as the electrolyte, the cells were encapsulated in an argon atmosphere glove box with both water pressure and oxygen partial pressure not exceeding 0.1 ppm to obtain a CR2032 coin-type lithium-ion secondary battery.
[0057] The electrochemical performance of the CR2032 lithium-ion battery was tested at room temperature using a constant current charge-discharge mode. To evaluate the cycle stability of the material, a voltage range of 0.01V–3.0V (vs. Li) was used. + Within the voltage range of / Li), at 0.1 A·g -1 Charge-discharge tests were conducted at a current density, and the charge specific capacity and capacity retention rate after 100 cycles were as follows: Figure 2 As shown, the active material (4M) prepared in Example 1 was at 0.1 A·g -1 At current densities, (Cr 0.2 Mn 0.2 Fe 0.2 Co 0.2 The specific capacity of the 3O4 electrode during the first charge cycle is 708.3 mAh·g. -1 After 100 cycles, the charging specific capacity is 528.9 mAh·g. -1 The capacity retention rate was 74.67%; the active material (4M-Al) prepared in Example 2 was at 0.1 A·g -1 At current densities, (Cr 0.2 Mn 0.2 Fe 0.2 Co 0.2 Al 0.2 The specific capacity of the 3O4 electrode during the first charge cycle is 638.8 mAh·g. -1 After 100 cycles, the charging specific capacity is 570.98 mAh·g. -1 The capacity retention rate was 89.38%; the first-cycle charge specific capacity of the Ti-doped oxide (4M-Ti) electrode prepared in Comparative Example 1 was 671.2 mAh·g. -1After 100 cycles, the charging specific capacity is 450mAh·g. -1 The capacity retention rate was 67%. It is evident that the spinel single-phase high-entropy oxide prepared in Example 2 outperformed the quaternary spinel oxide in Example 1 and far surpassed the doped Ti oxide anode without a single phase prepared in Comparative Example 1, demonstrating excellent electrochemical cycling performance and capacity retention.
[0058] Meanwhile, to examine the rate performance of the material, tests were conducted sequentially at 0.1 A·g -1 0.2A·g -1 0.5A·g -1 1A·g -1 2A·g -1 5A·g -1 and backtesting 0.1 A·g -1 The tests were conducted at the aforementioned current density, and after 10 cycles at each current density, the (Cr) prepared in Example 1 was tested. 0.2 Mn 0.2 Fe 0.2 Co 0.2 The 3O4 electrode sequentially releases 593.7 mAh·g -1 509mAh·g -1 413.8mAh·g -1 340.6mAh·g -1 259mAh·g -1 141.4 mAh·g -1 The charging specific capacity, when the current density recovers to 0.1 A·g -1 At that time, the reversible charging specific capacity recovered to 530.7 mAh·g. -1 Example 2 prepared (Cr) 0.2 Mn 0.2 Fe 0.2 Co 0.2 Al 0.2 The 3O4 electrode sequentially releases 581.4 mAh·g -1 510.4mAh·g -1 418.4mAh·g -1 339.7mAh·g -1 253.5mAh·g -1 137.5mAh·g -1 The charging specific capacity, when the current density recovers to 0.1 A·g -1 At that time, the reversible charging specific capacity recovered to 541.9 mAh·g. -1 The Ti-doped oxide prepared in Comparative Example 1 sequentially released 515.8 mAh·g. -1 433.7mAh·g-1 344.6 mAh·g -1 266.5mAh·g -1 171.4mAh·g -1 56.5mAh·g -1 When the current density returns to 0.1 A·g -1 At that time, the reversible charging specific capacity recovered to 477mAh·g -1 The results are as follows: Figure 3 As shown, Example 2 exhibits higher reversibility, which is superior to Example 1 and far superior to the Ti-doped sample anode of Comparative Example 1.
[0059] The spinel-type high-entropy oxide with a single-phase structure prepared in this invention exhibits superior electrochemical performance, such as higher specific capacity, excellent cycle stability, and outstanding rate performance, outperforming low-component medium-entropy oxides and high-entropy oxides with heterogeneous structures. The single-phase high-entropy oxide achieves a uniform distribution of multiple main components, without component segregation or impurity phase enrichment, ensuring the repeatability and reliability of material performance. The presence of impurity phases can lead to deactivation of active materials, induce volume expansion, and disrupt the overall structural integrity of the material, thereby exacerbating cycle degradation.
Claims
1. A cycle-stable spinel-phase high-entropy oxide anode material, characterized in that, The spinel-phase high-entropy oxide is composed of equimolar ratios of metallic elements Cr, Mn, Fe, Co, and M, where M is any one of Li, Na, Mg, Zn, Cu, and Al.
2. The cycle-stable spinel-phase high-entropy oxide anode material according to claim 1, characterized in that, The spinel-phase high-entropy oxide is (Cr) 0.2 Mn 0.2 Fe 0.2 Co 0.2 M 0.2 )3O4 has a spinel single-phase structure.
3. The method for preparing a cycle-stable spinel-phase high-entropy oxide anode material according to claim 1, characterized in that, The spinel-phase high-entropy oxide is obtained by mixing oxides of metallic elements Cr, Mn, Fe, Co and M in equimolar ratio and calcining them.
4. The method for preparing a cycle-stable spinel-phase high-entropy oxide anode material according to claim 3, characterized in that, One of the following powders, Li2O, Na2O, MgO, ZnO, CuO, and Al2O3, is mixed with Cr2O3, Mn2O3, Fe2O3, and Co3O4 powders in an equimolar ratio of the metal elements. After ball milling, the mixture is calcined at a temperature of 800℃-1200℃ for 4h-18h. After cooling, the spinel-phase high-entropy oxide is obtained.
5. The method for preparing a cycle-stable spinel-phase high-entropy oxide anode material according to claim 4, characterized in that, The roasting temperature is 900℃ and the roasting time is 12h.
6. The method for preparing a cycle-stable spinel-phase high-entropy oxide anode material according to claim 3, characterized in that, The ball milling includes the following conditions: a ball-to-material ratio of 10:1, the use of zirconia grinding beads with diameters of 1 cm and 0.6 cm, the addition of ethanol as the grinding medium, a grinding speed of 300 rpm, and a grinding time of 3 hours; after ball milling, drying at 70°C and then calcining, with the temperature increased at a rate of 5°C / min to the required calcination temperature.
7. The application of the cycle-stable spinel-phase high-entropy oxide anode material according to claim 1, characterized in that, The spinel-phase high-entropy oxide is used as a negative electrode material for lithium-ion batteries.
8. The application of the cycle-stable spinel-phase high-entropy oxide anode material according to claim 7, characterized in that, Using the spinel phase high-entropy oxide as the active material, the active material, conductive agent, and binder are made into a slurry, which is then coated onto a copper foil current collector and dried to obtain an electrode sheet. The electrode sheet is used as the working electrode, and the lithium metal sheet is used as the counter electrode. The lithium metal sheet, along with the separator and electrolyte, are then encapsulated to obtain the lithium-ion battery.
9. The application of the cycle-stable spinel-phase high-entropy oxide anode material according to claim 8, characterized in that, The conductive agent includes superconducting carbon black, the binder includes polyvinylidene fluoride, and the mass ratio of the active material, conductive agent and binder is 7:2:
1. N-methylpyrrolidone is added as a dispersant, and the mixture is thoroughly ground to form a uniform slurry. The slurry is coated onto the copper foil current collector, dried under vacuum at 120°C for 8 hours, and then punched to obtain the electrode sheet.
10. The application of the cycle-stable spinel-phase high-entropy oxide anode material according to claim 8, characterized in that, Assembly was carried out in a glove box where the moisture pressure and oxygen partial pressure were both no higher than 0.1 ppm. Celgard 2400 microporous membrane was used as the separator, lithium hexafluorophosphate solution was used as the electrolyte, and coin-type lithium-ion batteries were obtained after encapsulation.