Application of YCrTeO6 negative electrode material in battery

Abstract

According to the application of the YCrTeO6 negative electrode material in the battery, the YCrTeO6 negative electrode material is introduced into the battery, the synergistic effect of Cr < 3 + > antiparallel spin arrangement and YO6 layer spontaneous dipole moment is utilized, and organic combination of electronic structure regulation and control and ion transmission optimization is achieved through the magnetoelectric coupling effect; the specific capacity and the cycle performance of the battery containing the negative electrode material are further improved, the initial specific capacity of the battery at 0.1 A.g <-1 > is 571.0 mAh.g <-1 >, after 1000 cycles under the current density, the capacity is almost not attenuated, the coulombic efficiency is close to 100%, and the battery has excellent cycle stability.

Description

Technical Field

[0001] This invention belongs to the field of batteries, specifically relating to the application of YCrTeO6 anode material in batteries. Background Technology

[0002] While lithium-ion batteries (LIBs) dominate the market, the abundance and uneven distribution of lithium resources, their core raw material, in the Earth's crust (only 0.0065%) leads to drastic cost fluctuations. Therefore, potassium-ion batteries (PIBs), due to their abundant potassium resources and similar ion insertion / extraction mechanisms to LIBs, are considered one of the most promising alternative technologies. (The last sentence appears to be incomplete and possibly refers to a different topic.) + Reversible intercalation and deintercalation between positive and negative electrode materials enables charge storage, with a theoretical energy density exceeding 300 Wh / kg, sufficient to meet the energy storage needs of electric vehicles and the power grid. The large-scale application of potassium-ion batteries depends on technological breakthroughs in negative electrode materials; therefore, it is necessary to develop negative electrode materials that can improve the capacity of potassium-ion batteries.

[0003] The development of potassium-ion battery anode materials is currently constrained by three factors: poor ion diffusion kinetics, severe interfacial side reactions, and decoupling of electron-ion transport. Although traditional electrochemical strategies such as element doping and nanostructure design can partially improve these problems, they are difficult to overcome the limitations of single physical field modulation. For example, while element doping can improve electron conduction, doping generally introduces structural defects, leading to uneven potassium ion adsorption energy and hindering ion diffusion; while nanostructure design shortens the ion diffusion distance, it increases the specific surface area, exacerbating interfacial side reactions.

[0004] Recent research reports the introduction of physical field modulation at the sodium-ion battery interface to construct a magnetic Fe3O4 interface layer on the P-NM surface. This technique disperses the ion flow through Lorentz force-induced lateral forces, alleviating interfacial ion aggregation and improving the performance of Na+ batteries. + The diffusion coefficient was 76% after 500 cycles at a current density of 5 C. Although the magnetic Fe3O4 interface layer can improve the sodium ion diffusion coefficient, it cannot optimize the conductivity of the material. Furthermore, this technology has the following defects: (1) Single regulation mechanism: It only affects the ion trajectory through the Lorentz force generated by the external magnetic field, without involving electronic structure regulation, and cannot simultaneously optimize the conductivity of the material and the ion diffusion dynamics. (2) Insufficient structural stability: The interface coupling between the magnetic layer and the host material is weak, and structural degradation may still occur due to lattice mismatch during long-term cycling. (3) Lack of field effect synergy: The synergistic effect of the magneto-electrophysical field is not realized, making it difficult to simultaneously solve the multiple challenges of ion transport, electronic conduction and interface stability.

[0005] Therefore, existing potassium-ion battery anode materials still cannot meet the requirements of high-efficiency energy storage, and there is still an urgent need to find a new strategy to improve the performance of potassium-ion batteries. Summary of the Invention

[0006] In order to overcome at least one of the technical problems existing in the prior art, one of the objectives of the present invention is to provide an application of YCrTeO6 anode material in batteries.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The first aspect of the present invention provides the application of YCrTeO6 anode material in batteries.

[0008] In some embodiments of the present invention, the battery is selected from potassium-ion batteries, lithium-ion batteries, or sodium-ion batteries.

[0009] When YCrTeO6 anode material is applied to potassium-ion batteries, the following effects can be achieved: (1) Breakthrough K + Diffusion kinetics constraints, utilizing the built-in electric field generated by ferroelectric polarization to directionally drive K + Migration reduces disordered collisions during the diffusion process, shortening K's time without introducing structural defects. + (2) The migration distance reduces the diffusion barrier; (3) Antiferromagnetic order may affect Cr through spin-orbit coupling (SOC). 3+ The orientation of the t2g orbital affects the electron transport in the Cr-O-Te-O-Cr conduction channel. When the electron spin direction matches the orbital symmetry, it may correspond to a higher electron transport efficiency. (3) Construct a multi-physics field synergistic control mechanism: For the first time, the magnetoelectric coupling effect is introduced into the negative electrode of the potassium ion battery to realize the organic combination of electronic structure control and ion transport optimization, and solve the technical gap that the magnetic interface layer of the potassium ion battery is not combined with the ferroelectric polarization.

[0010] In some embodiments of the present invention, the battery contains a negative electrode, which contains an active material, a conductive agent, and a binder; the active material includes YCrTeO6 negative electrode material.

[0011] In some embodiments of the present invention, the mass ratio of the YCrTeO6 anode material to the conductive agent is 7:(1~3); in some embodiments of the present invention, the mass ratio of the YCrTeO6 anode material to the conductive agent is any value of 7:1, 7:1.5, 7:2, 7:2.5, 7:3 or a range formed by any two of them.

[0012] In some embodiments of the present invention, the mass ratio of the YCrTeO6 anode material to the binder is 7:(0.5~2); in some embodiments of the present invention, the mass ratio of the YCrTeO6 anode material to the binder is any value of 7:0.5, 7:0.8, 7:1, 7:1.2, 7:1.4, 7:1.5, 7:1.6, 7:1.8, 7:2 or a range formed by any two of these values.

[0013] In some embodiments of the present invention, the conductive agent includes at least one of graphite, graphene, carbon fiber, acetylene black, conductive carbon black, and carbon nanotubes.

[0014] In some embodiments of the present invention, the adhesive includes at least one of sodium carboxymethyl cellulose, potassium carboxymethyl cellulose, styrene-butadiene rubber, polyacrylic acid, polyvinylidene fluoride, and polytetrafluoroethylene.

[0015] In some embodiments of the present invention, the YCrTeO6 anode material has a honeycomb porous structure.

[0016] In some embodiments of the present invention, the YCrTeO6 anode material is in a single crystal state.

[0017] In this invention, the microstructure and magnetoelectric properties of the YCrTeO6 anode material are deeply coupled, and the honeycomb porous structure can provide abundant K. + Adsorption sites; single-crystal grains ensure Cr 3+ The long-range order of the spin arrangement and the antiferromagnetic order ensure efficient electron transport, while the built-in electric field generated by ferropolarization improves the potassium ion diffusion coefficient.

[0018] In some embodiments of the present invention, the YCrTeO6 anode material is prepared by a method comprising the following steps: Y2O3, Cr2O3 and TeO2 are pre-sintered, then formally sintered and cooled to obtain the YCrTeO6 anode material.

[0019] In some embodiments of the present invention, the molar ratio of Y2O3, Cr2O3 and TeO2 is 1:1:2.

[0020] In some embodiments of the present invention, the preparation method includes a grinding step; the grinding step is located after the pre-sintering step and before the formal sintering step.

[0021] In some embodiments of the present invention, the grinding time is 20 to 60 minutes.

[0022] In some embodiments of the present invention, the pre-sintering temperature is 280~600℃; in some embodiments of the present invention, the pre-sintering temperature is any value of 280℃, 300℃, 400℃, 450℃, 500℃, 550℃, 600℃ or a range formed by any two of them.

[0023] In some embodiments of the present invention, the pre-sintering time is 1 to 4 hours; in some embodiments of the present invention, the pre-sintering time is any value of 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, or a range formed by any two of these values.

[0024] In this invention, the pre-sintering step is to remove moisture and volatile impurities from Y₂O₃, Cr₂O₃, and TeO₂, purifying the raw materials, activating the pre-reaction, and regulating their chemical state. This lays the foundation for the subsequent high-temperature synthesis of high-quality YCrTeO₆, ultimately improving the material's magnetoelectric coupling performance and electrochemical stability. Increasing the temperature can accelerate the removal of moisture and volatile impurities (such as adsorbed CO₂ and organic residues) from the raw materials, but it is necessary to avoid exceeding the decomposition temperature of raw materials such as TeO₂ (TeO₂ melting point approximately 733°C) to prevent TeO₂ volatilization or valence state changes. If the temperature is too low, insufficient thermal activation may lead to residual moisture or impurities participating in subsequent high-temperature reactions, introducing impurity phases.

[0025] In some embodiments of the present invention, the formal sintering temperature is 900~1000℃; in some embodiments of the present invention, the formal sintering temperature is any value or a range formed by any two of 900℃, 910℃, 920℃, 930℃, 940℃, 950℃, 960℃, 970℃, 980℃, 990℃, and 1000℃.

[0026] In some embodiments of the present invention, the heating rate for the formal sintering is 3~8℃ / min; in other embodiments, the heating rate for the formal sintering is any value of 3℃ / min, 4℃ / min, 5℃ / min, 6℃ / min, 7℃ / min, or 8℃ / min, or a range formed by any two of these values. If the temperature rises too quickly during calcination, TeO2 may locally overheat and volatilize before reaching the reaction temperature. Slow heating allows TeO2, Y2O3, and Cr2O3 to participate in the solid-phase reaction simultaneously, reducing Te loss. If the temperature rises too slowly during calcination, the heating time will be prolonged, leading to increased production costs and potentially causing side reactions.

[0027] In some embodiments of the present invention, the formal sintering time is 10-15 hours; in other embodiments, the formal sintering time is any value of 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, or 15 hours, or a range formed by any two of these values. The synthesis of YCrTeO6 requires a multi-step solid-state reaction. Sintering at a controlled temperature for 10-15 hours ensures sufficient diffusion between raw material particles, avoiding residual Y2O3 or Cr2O3 due to incomplete reaction; and it also promotes the directional growth of YCrTeO6 grains, forming single crystal grains.

[0028] The present invention adopts the above-mentioned formal sintering conditions, and slowly heats up at a low heating rate to avoid compositional imbalance caused by TeO2 volatilization, thereby achieving synergistic optimization of material microstructure and magnetoelectric properties.

[0029] In some embodiments of the present invention, the cooling is performed by first cooling to 580-620°C at a first cooling rate of 5-10°C / min, and then cooling to 20-40°C at a second cooling rate of 20-25°C / min.

[0030] In some embodiments of the present invention, the first cooling rate is any value of 5℃ / min, 6℃ / min, 7℃ / min, 8℃ / min, 9℃ / min, 10℃ / min, or a range formed by any two of these values.

[0031] In some embodiments of the present invention, the temperature is first cooled at a first cooling rate of 5~10℃ / min to any value of 580℃, 590℃, 600℃, 610℃, 620℃ or a range formed by any two of them.

[0032] In some embodiments of the present invention, the second cooling rate is any value of 20℃ / min, 21℃ / min, 22℃ / min, 23℃ / min, 24℃ / min, 25℃ / min, or a range formed by any two of them.

[0033] In some embodiments of the present invention, the temperature is reduced at a second cooling rate of 20~25℃ / min to any value or a range formed by any two of the following: 20℃, 22℃, 24℃, 25℃, 26℃, 28℃, 30℃, 32℃, 34℃, 35℃, 36℃, 38℃, and 40℃.

[0034] This invention employs a segmented cooling method to maintain Cr 3+ The antiparallel spin alignment and the stability of the YO6 layer dipole moment ensure the continuity of the magnetoelectric coupling effect. This allows for control of grain size and defect density. In the first cooling stage, the cooling rate is slow; this gradual cooling reduces internal crystal stress and avoids lattice distortion caused by thermal expansion and contraction, thus maintaining the stability of Cr.3+ The long-range order of the spin arrangement and the rapid cooling rate in the second cooling stage are intended to promote uniform relaxation of the YO6 octahedron and ensure the stable existence of the spontaneous dipole moment required for ferroelectric polarization. On the other hand, it can suppress the secondary volatilization of TeO2. If the temperature is dropped too quickly, the TeO2 dissolved at high temperature may re-precipitate and volatilize, leading to an imbalance in the stoichiometry of YCrTeO6. The staged cooling can form a stable lattice below 580~620℃, fixing the positions of Te atoms.

[0035] The beneficial effects of this invention are: This invention introduces YCrTeO6 anode material into the battery, utilizing Cr... 3+ The synergistic effect of antiparallel spin alignment (antiferromagnetic) and spontaneous dipole moment (ferroelectric) of YO6 layers achieves an organic combination of electronic structure regulation and ion transport optimization through the "magnetoelectric coupling" effect, thereby improving the specific capacity and cycle performance of batteries containing YCrTeO6 anode materials. The battery achieves a cycle performance of 0.1 A·g -1 The initial specific capacity is 571.0 mAh·g. -1 After 1000 cycles at this current density, the capacity showed almost no decay (541.7 mAh·g). -1 It has a capacity retention rate of >94% and a coulombic efficiency close to 100%, exhibiting excellent cycle stability. Attached Figure Description

[0036] Figure 1 This is a flowchart illustrating the preparation process of the potassium-ion battery in Example 1.

[0037] Figure 2 The images show the XRD patterns of materials Y1, Y2, and Y3 from Example 1 and Comparative Examples 1-2.

[0038] Figure 3 The XPS full spectra of the three materials Y1, Y2 and Y3 in Example 1 and Comparative Examples 1-2 are shown.

[0039] Figure 4 for Figure 3 Peak distribution diagrams of the three materials.

[0040] Figure 5 The images shown are SEM, SAED, and TEM images of YCrTeO6 from Example 1.

[0041] Figure 6 The above are the HAADF diagram and elemental mapping diagram of YCrTeO6 in Example 1.

[0042] Figure 7 The batteries assembled from the materials of Example 1 and Comparative Examples 1-2 were tested at 0.1 A·g. -1 The following is a graph showing the electrochemical performance test results.

[0043] Figure 8 The battery assembled from the materials of Example 1 and Comparative Examples 1-2 was tested at 1 A·g. -1 The following is a graph showing the electrochemical performance test results.

[0044] Figure 9 The graph shows the rate performance test results of the batteries assembled from the materials of Example 1 and Comparative Examples 1-2.

[0045] Figure 10 The graph shows the GITT titration curve of the battery assembled from the materials of Example 1.

[0046] Figure 11 The graph shows the GITT titration curve of the battery assembled from the materials of Comparative Example 1.

[0047] Figure 12 The graph shows the GITT titration curve of the battery assembled from the materials of Comparative Example 2.

[0048] Figure 13 This is a diagram showing the potassium ion diffusion coefficient of a battery assembled from the materials of Example 1.

[0049] Figure 14 The diagram shows the potassium ion diffusion coefficient of the battery assembled from the materials of Comparative Example 1.

[0050] Figure 15 The diagram shows the potassium ion diffusion coefficient of the battery assembled from the materials of Comparative Example 2.

[0051] Figure 16 Y1 in Example 1 at 0.1 mV·s -1 The CV curve at that time.

[0052] Figure 17 The image shows the CV curves of Y1 at different scan rates in Example 1.

[0053] Figure 18 The pseudocapacitive contribution diagram of Y1 at different scan rates is shown in Example 1.

[0054] Figure 19 The image shows the CV curves of Y2 at different scan rates in Comparative Example 1.

[0055] Figure 20 The pseudocapacitive contribution of Y2 at different scan rates is shown in Comparative Example 1.

[0056] Figure 21 The image shows the CV curves of Y3 at different scan rates in Comparative Example 2.

[0057] Figure 22 The pseudocapacitance contribution of Y3 in Comparative Example 2 at different scan rates is shown in the figure.

[0058] Figure 23 The impedance spectra of the materials in Example 1 and Comparative Examples 1-2 before cycling are shown.

[0059] Figure 24 The impedance spectra of the materials in Example 1 and Comparative Examples 1-2 after cycling are shown. Detailed Implementation

[0060] The specific implementation of the present invention will be further described in detail below with reference to the accompanying drawings and examples, but the implementation and protection of the present invention are not limited thereto. It should be noted that any processes not specifically described in detail below are those that can be implemented or understood by those skilled in the art by referring to the prior art. Reagents or instruments used without specified manufacturers are all conventional products that can be purchased commercially.

[0061] Example 1 like Figure 1 The flowchart shown illustrates a method for preparing a negative electrode material for potassium-ion batteries, comprising the following steps: First, the required oxide materials (i.e., Y2O3, Cr2O3 and TeO2) are calcined at 300℃ for 2 hours. Then, Y2O3, Cr2O3 and TeO2 are weighed in a molar ratio of 1:1:2 and ground in a mortar for 30 minutes. The mixture is then transferred to an alumina crucible, taking care to avoid clumping during the transfer process. The mixture is then placed in a small box furnace for calcination. The calcination program is set to heat the mixture from room temperature to 950℃ at a heating rate of 5℃ / min and hold it at that temperature for 12 hours. Then, the temperature is lowered to 600℃ for two days (i.e., 48 hours) and then to room temperature for another day (i.e., 24 hours). This yields YCrTeO6 powder with magnetoelectric coupling effect, denoted as Y1.

[0062] The initial calcination of the required oxide materials at 300℃ for 2 hours is to remove moisture and volatile impurities from the raw materials, purifying them, activating the pre-reaction, and regulating their chemical state. This lays the foundation for the subsequent high-temperature synthesis of high-quality YCrTeO6, ultimately improving the material's magnetoelectric coupling performance and electrochemical stability. Increasing the temperature can accelerate the removal of moisture and volatile impurities (such as adsorbed CO2 and organic residues) from the raw materials, but the temperature must be avoided from exceeding the decomposition temperature of raw materials such as TeO2 (TeO2 melting point is approximately 733℃) to prevent volatilization or valence state changes. Decreasing the temperature requires extending the calcination time to ensure sufficient impurity removal; otherwise, insufficient thermal activation may lead to residual moisture or impurities participating in subsequent high-temperature reactions, introducing impurity phases.

[0063] The calcination process is set because the melting point of TeO2 in the raw material is 733℃. If the temperature rises too quickly during calcination, TeO2 may locally overheat and volatilize before reaching the reaction temperature. Slow heating (e.g., 5℃ / min) allows TeO2 to participate in the solid-phase reaction simultaneously with Y2O3 and Cr2O3, reducing Te loss.

[0064] The necessity of holding the temperature for 12 hours is as follows: The synthesis of YCrTeO6 requires a multi-step solid-state reaction. Holding the temperature for 12 hours can ensure sufficient diffusion between raw material particles and avoid residual Y2O3 or Cr2O3 due to incomplete reaction. Holding the temperature for a long time can promote the directional growth of YCrTeO6 grains and form single crystal grains.

[0065] The necessity of staged cooling: Firstly, it controls grain size and defect density. Cooling to 600℃ over two days (i.e., a cooling rate of approximately 7.3℃ / min) and slow cooling can reduce internal stress in the crystal, avoid lattice distortion caused by thermal expansion and contraction, and maintain Cr... 3+ The long-range order of the spin arrangement, and the cooling to room temperature over a day (i.e., a cooling rate of approximately 24°C / min), is to further reduce the cooling rate, promote uniform relaxation of the YO6 octahedron, and ensure the stable existence of the spontaneous dipole moment required for ferroelectric polarization. Secondly, it suppresses the secondary volatilization of TeO2. If the temperature is reduced rapidly, the TeO2 dissolved at high temperatures may re-precipitate and volatilize, leading to an imbalance in the stoichiometry of YCrTeO6. Staged cooling can form a stable lattice below 600°C, fixing the positions of the Te atoms.

[0066] Comparative Example 1 This example provides a method for preparing a negative electrode material for potassium-ion batteries, including the following steps: After re-grinding the Y1 powder from Example 1, it was placed in an alumina crucible and heated to 1323 K (i.e. 1050 ℃) in air at a heating rate of 5 ℃ / min, and held at that temperature for 6 hours. The higher temperature was used to accelerate the volatilization of Te and generate the YCrO3 phase, resulting in YCrTeO6 / YCrO3 (ferroelectricity destroyed) material, denoted as Y2.

[0067] Comparative Example 2 This example provides a method for preparing a negative electrode material for potassium-ion batteries, including the following steps: Using paramagnetic Mn 3+ (3d) 4 Electronic configuration, high spin state) replacing Cr 3+ (3d) 3To achieve the desired effect (low-spin antiferromagnetic state), the antiferromagnetic order is disrupted while preserving the ferroelectric polarization capability of the YO6 layer. Y₂O₃, MnCO₃, and TeO₂ are weighed in a molar ratio of 1:2.1:2, with MnCO₃ in excess (5%) to compensate for high-temperature decomposition losses. The mixture is placed in an Ar atmosphere (to prevent Mn…). 3+ The mixture was heated to 900°C at a heating rate of 5°C / min during a disproportionation reaction in air, held at that temperature for 15 hours, cooled to 600°C for two days, and then cooled to room temperature for one day to obtain YMnTeO6 (antiferromagnetism destroyed) powder material, denoted as Y3.

[0068] Example 2 This example provides a potassium-ion battery and its preparation method, wherein the potassium-ion battery is a CR2032 button cell, and its preparation steps are as follows: 70% by weight of active material (i.e., Y1 in Example 1), 20% by weight of acetylene black (Super P), and 10% by weight of PVDF were ground in a mortar for 15-20 min, then transferred to a 5 mL beaker, and 900 mL of N-methylpyridinone (NMP) was added. The mixture was stirred at room temperature for 24 hours to prepare a negative electrode material slurry. The negative electrode material slurry was then coated onto aluminum foil using a 100 µm scraper and vacuum dried at 70 °C for 12 h to prepare a circular negative electrode sheet with a radius of 6 mm. The loading of active material Y1 was 1.8 mg (the loading of Y2 and Y3 in Comparative Examples 3-4 was the same as that of Y1). The separator was composed of glass fiber sheets with a radius of 9 mm. The electrolyte was 3 mol / L potassium bis(fluorosulfonyl)imide (KFSI) dissolved in dimethyl ether. The mixture was then assembled into a CR2032 button cell.

[0069] Comparative Example 3 The only difference between the preparation method of the potassium-ion battery in this example and that in Example 2 is that Y2 from Comparative Example 1 is used as the active material in this example.

[0070] Comparative Example 4 The only difference between the preparation method of the potassium-ion battery in this example and that in Example 2 is that Y3 from Comparative Example 2 is used as the active material in this example.

[0071] Performance testing: The diffraction peaks of Y1, Y2, and Y3 were measured using an X-ray diffractometer, as follows: Figure 2 As shown, the XRD pattern of Y1 is as follows: Figure 2 As shown in (a) above, the XRD patterns of Y2 and Y3 are as follows: Figure 2 As shown in (b) of the diagram. Then, the XPS full spectra of Y1, Y2, and Y3 were tested, as shown in... Figure 3 As shown; where, Figure 3The XPS peak distribution plots of Y1, Y2, and Y3 are shown below. Figure 4 As shown in (a)~(f) in the figure, the peak distribution of O 1s is as follows: Figure 4 As shown in (a) above, the peak distribution of Te 3d is as follows: Figure 4 As shown in (b); the peak distribution of Cr 2p is as follows. Figure 4 As shown in (c); the peak distribution diagram of Y3d is as follows. Figure 4 The peak distribution of (d) Mn 2p is shown in the figure. Figure 4 As shown in (e); the C 1s peak plot is as follows Figure 4 As shown in (f) in the figure.

[0072] Depend on Figure 2 As shown in (a) to (b), the diffraction peaks of Y1 are in high agreement with the theoretical fit; Y2 is due to interfacial strain introduced by heterogeneous lattice mismatch, and Y3 is due to Mn 3+ Induced octahedral distortion resulted in a decrease in the intensity of the XRD peaks in both Y2 and Y3. XPS full-spectrum analyses confirmed the successful synthesis of the three materials, Y1, Y2, and Y3. Y, Cr, Te, O, and C elements were detected in Y1 and Y2, while Y, Mn, Te, O, and C elements were detected in Y3. Figure 4 As shown in (a), the Metal-O peak (529.8 eV) of Y1 corresponds to the YO6 octahedron and Cr-O-Te bonds to stabilize the electron cloud density; the Metal-O in Y2 also participates in bioctahedral coordination, while the MnO6 octahedron in Y3 undergoes axial elongation and longitudinal contraction. Both peak broadening and shift are caused by the heterogeneity of oxygen coordination. Figure 4 From (b) we can see that Te of Y1 6+ The price state is stable, and electron transfer at the Y2 interface causes partial reduction of Te (Te 6+ Restored to Te 4+ (The binding energy decreases), the hybridization of Mn 3d and Te 5p orbitals in Y3 weakens the Te oxidation state, and the peak shifts to a lower binding energy. Figure 4 From (c), we can see that Cr element is Cr 3+ In Y3, Mn disrupts the spin order of Cr, enhancing d-orbital hybridization and broadening the peak shape. Figure 4 The (d) in the figure shows that the peaks of Y2 and Y3 are shifted. This is because the lattice mismatch at the Y2 interface and the local electric field distortion introduced by Mn in Y3 cause the shift of the Y3d peak. Figure 4 (e) in the diagram is the spectrum of Mn 2p in Y3, Mn 3+ The Jahn-Teller distortion causes the Mn 2p3 / 2 peak to split into Mn 3+ (641.5 eV) and Mn 4+ (642.5 eV). Figure 4(f) indicates that the C1s peak is the C peak of the three materials (CC, COC, C=O).

[0073] To observe the microstructure and morphology of YCrTeO6 material, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) tests were performed. The SEM image of YCrTeO6 material is shown below. Figure 5 As shown in (a) to (c), Figure 5 The scale bars in figures (a) to (c) are 2 μm, 500 nm, and 200 nm, respectively. The selected area electron diffraction (SAED) pattern of YCrTeO6 material is shown below. Figure 5 As shown in (d), the transmission electron microscope image and lattice fringes of YCrTeO6 are as follows. Figure 5 As shown in (e) and (f), the HADDF (High-Angle Annular Dark-Field) of YCrTeO6 and the elemental mapping diagram of YCrTeO6 are as follows. Figure 6 As shown. By Figure 5 As shown in (a) to (c), the surface of the Y1 material is densely covered with micron-sized pores, forming a honeycomb-like network structure. This porous structure provides more K + Adsorption / desorption sites enhance capacity, help alleviate stress, suppress volume changes, and improve cycling stability. Figure 5 As shown in (d), the diffraction spots are periodically arranged and not circulated, which proves that the YCrTeO6 particles are single crystal domains. Figure 5 (e) shows that the particles exhibit a regular octahedral single crystal morphology with clear crystal faces and smooth surfaces, indicating that the material has a high degree of crystallinity. Figure 5 The high-resolution TEM image (f) in the image can identify the Y1(102) crystal plane. Figure 6 The HAADF and elemental mapping results show that the distributions of Y, Cr, Te, and O elements are highly overlapping, with no obvious segregation or impurity phases (the C signal is due to environmental pollution and can be ignored), confirming that the material is a single-phase YCrTeO6.

[0074] The CR2032 button batteries prepared in Examples 2 and 3-4 were placed in a glove box and their electrochemical performance was tested under an argon atmosphere with low oxygen and low water conditions. A LANDdt (LAND CT 3004A) battery testing system was used to perform constant current charge-discharge curves, constant current intermittent titration (GITT), long-cycle testing, and rate performance (0.01-3V) testing at 27°C. An electrochemical workstation (CHI-760E) was used to test CV curves and pseudocapacitance. Specific test results are as follows: Figures 7-15 As shown.

[0075] As shown in Figures 7 and 8, due to the magnetoelectric coupling effect, Y1 at 0.1 A·g -1After cycling for 1000 cycles at a current density, the capacity showed almost no decay (541.7 mAh·g). -1 The coulombic efficiency is close to 100%, far exceeding that of Y2 (232.9 mAh·g). -1 ) and Y3 (276.5 mAh·g -1 It exhibits excellent cycle stability; at a current density of 1.0 A·g -1 At that time, the discharge capacity of Y1 also far exceeded that of Y2 and Y3. Figure 9 The values ​​of Y1, Y2, and Y3 in the range of 0.1–10 A·g were demonstrated. -1 Capacity retention capability at various rates, at 0.1 A·g -1 At that time, the Y1 capacity reached 571.0 mAh·g -1 Even at 10 A·g -1 (Under ultra-fast charging conditions) the capacity remains at 56.5mAh·g -1 And when the current density recovers to 0.1 A·g -1 At that time, the capacity also recovered to the initial value, indicating that the charge-discharge process is reversible; however, the rate performance of Y2 and Y3 is significantly lower than that of Y1, when the current density is 0.1 A·g -1 At that time, the discharge capacity of Y3 was 285.3 mAh·g. -1 Y2 is 223.7 mAh·g -1 When the current density increases to 10 A·g -1 At that time, the discharge capacity of Y3 was 15.5 mAh·g. -1 Y2 is 6.8 mAh·g -1 It is much lower than Y1. Figure 10-12 The GITT titration curves for Y1, Y2, and Y3 are shown. Figures 13-15 The potassium ion diffusion coefficients of Y1, Y2, and Y3 are shown, and the K of Y1 is... + The diffusion coefficient remained at 1×10 -10 cm 2 ·s -1 Higher than Y2 (1.5×10 -11 cm 2 ·s -1 ) and Y3 (2.3×10 -11 cm 2 ·s -1 It is worth mentioning that the discharge capacity, rate performance, and potassium ion diffusion coefficient of Y2 and Y3 are not significantly different, indicating that the performance improvement is due to the effect of magnetoelectric coupling rather than a single physical field modulation.

[0076] To verify the influence of magnetoelectric coupling on the contribution of pseudocapacitance, CV and pseudocapacitance tests were performed at different scan rates on batteries assembled from Y1, Y2, and Y3 materials using an electrochemical workstation (CHI-760E). Specific test results are as follows: Figures 16-24 As shown.

[0077] Depend on Figure 16 It can be seen that at 0.1 mV·s -1 At the scan rate of time, the CV curves of the second and third cycles of Y1 almost completely overlap, with no significant shift in peak position or shape, reflecting that the magnetoelectric coupling effect stabilizes the lattice structure and the charge storage process is highly reversible. Figure 17 , Figure 19 and Figure 21 It can be seen that when the scan rate starts from 0.2 mV·s -1 Increased to 1.0 mV·s -1 At the same scan rate, the peak shape integrity of Y1 remained consistent, while Y2 showed significant broadening at high scan rates (1.0 mV / s), indicating a decrease in ion transport rate. Y3 showed weak peak current growth with increasing scan rate. Figure 18 , Figure 20 and Figure 22 It can be seen that when the scan rate increases to 1.0 mV·s -1 At that time, the pseudocapacitance of Y1 jumped to 88%, while that of Y2 was at 1.0 mV·s. -1 The pseudocapacitance contributes 68%, while Y3 at 1.0 mV·s -1 The pseudocapacitance contributes 70%. This is because the magnetoelectric coupling effect in Y1 imparts a fast charge response and high pseudocapacitance, while in Y2, due to Te volatilization, the "Cr-O-Te-O-Cr" orbital network breaks down, hindering electron transport. Simultaneously, the disappearance of the ferroelectric polarization field causes K... + Diffusion disorder reduces the contribution of pseudocapacitance. Mn in Y3 3+ e g Asymmetric orbital occupancy induces Jahn-Teller distortion, disrupts orbital matching in superexchange, destroys antiferromagnetic order, hinders electron transport, reduces pseudocapacitive contribution, and causes peak asymmetry. These results demonstrate that magnetoelectric coupling can drive the shift in charge storage towards pseudocapacitive dominance. Figure 23 and Figure 24 Electrochemical impedance spectroscopy (EIS) showed that Y1 had the smallest high-frequency semicircle radius and a high Warburg impedance slope in the low-frequency region, with a gradual impedance increase after 1000 cycles. Y2 and Y3 had significantly larger high-frequency semicircle radii and lower slopes in the low-frequency region, with a sharp increase in impedance after cycling, indicating that K... + The improvement of diffusion performance and the maintenance of structural stability during cycling depend on the magnetoelectric coupling effect.

[0078] The magnetoelectric coupling effect is crucial as a core regulatory mechanism for improving the performance of potassium-ion battery anode materials. Antiferromagnetic ordering enhances electron mobility, overcoming the bottleneck of electron conduction, while the built-in electric field generated by ferroelectric polarization directionally drives K0. + Rapid migration significantly reduces the ion diffusion barrier, enabling simultaneous optimization of electron-ion transport dynamics. The magnetoelectric coupling effect fundamentally overcomes the limitations of single-physical-field control, simultaneously addressing bottlenecks such as slow ion diffusion and electron-ion transport decoupling. This provides indispensable functional mechanism support for the design of high-performance anode materials for potassium-ion batteries, opening up new directions for future research on potassium-ion battery materials.

[0079] The embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. Application of YCrTeO6 anode material in batteries.

2. The application according to claim 1, characterized in that: The battery is selected from potassium-ion batteries, lithium-ion batteries, or sodium-ion batteries.

3. The application according to claim 1, characterized in that: The battery contains a negative electrode, which contains an active material, a conductive agent, and a binder; the active material includes YCrTeO6 negative electrode material.

4. The application according to claim 3, characterized in that: The mass ratio of the YCrTeO6 anode material to the conductive agent is 7:(1~3); And / or, the mass ratio of the YCrTeO6 anode material to the binder is 7:(0.5~2).

5. The application according to claim 3, characterized in that: The conductive agent includes at least one of graphite, graphene, carbon fiber, acetylene black, conductive carbon black, and carbon nanotubes. And / or, the adhesive includes at least one of sodium carboxymethyl cellulose, potassium carboxymethyl cellulose, styrene-butadiene rubber, polyacrylic acid, polyvinylidene fluoride, and polytetrafluoroethylene.

6. The application according to claim 1, characterized in that: The YCrTeO6 anode material has at least one of the following characteristics: (a1) The YCrTeO6 anode material has a honeycomb porous structure; (a2) The YCrTeO6 anode material is in a single crystal state.

7. The application according to claim 1, characterized in that: The YCrTeO6 anode material is prepared using a method comprising the following steps: Y2O3, Cr2O3 and TeO2 are pre-sintered, then formally sintered and cooled to obtain the YCrTeO6 anode material.

8. The application according to claim 7, characterized in that: The pre-sintering temperature is 280~600℃; And / or, the pre-sintering time is 1~4h.

9. The application according to claim 7, characterized in that: The formal sintering has at least one of the following characteristics: (b1) The temperature for the formal sintering is 900~1000℃; (b2) The heating rate for the formal sintering is 3~8℃ / min; (b3) The formal sintering time is 10~15h.

10. The application according to claim 7, characterized in that: The cooling process involves first cooling to 580-620℃ at a first cooling rate of 5-10℃ / min, and then cooling to 20-40℃ at a second cooling rate of 20-25℃ / min.

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