Preparation method and application of multivalent ion battery positive electrode based on magnetic field induced two-dimensional magnetic material vertical orientation

Abstract

The invention provides a preparation method and application of a multivalent ion battery positive electrode based on magnetic field induced vertical orientation of a two-dimensional magnetic material, and the preparation method comprises the following steps: dissolving a two-dimensional magnetic nanosheet, a single-walled carbon nanotube and polyacrylic acid in a solvent in proportion, and carrying out ultrasonic treatment to obtain uniform composite slurry; the composite slurry is injected into a rectangular mold of a current collector, a permanent magnet is arranged below the current collector, and a rotating magnetic field is generated by rotating the magnet; and under the action of a rotating magnetic field, inducing the two-dimensional magnetic material to realize vertical orientation self-assembly, and air-drying under the condition of a continuous rotating magnetic field to finally prepare the multivalent ion battery positive electrode with the vertical orientation structure. According to the preparation method and application of the multivalent ion battery positive electrode based on the magnetic field induced two-dimensional magnetic material vertical orientation, the ion transmission path can be effectively shortened, and the migration energy barrier is reduced, so that the energy density, the rate capability and the cycling stability of the battery are remarkably improved. The method has an important application prospect in the energy related field.

Description

Technical Field

[0001] This invention relates to the field of multivalent metal ion battery technology, and in particular to a device and method for measuring the laser-induced damage threshold of optical elements. Background Technology

[0002] Multivalent metal-ion batteries (with Mg) 2+ Al 3+ Traditional cathode materials (such as layered oxides or polyanionic compounds) using carriers typically provide low-dimensional diffusion channels (one-dimensional or two-dimensional). However, such structures are difficult to adapt to the strong polarization and size effects of multivalent ions, easily causing lattice distortion and irreversible capacity loss. Therefore, designing novel cathode structures that can promote efficient transport of multivalent ions is the core to overcoming technological bottlenecks.

[0003] At the microstructure level of electrodes, two-dimensional materials (such as graphene, transition metal sulfides (TMDs), and MXenes) have become ideal platforms for optimizing ion dynamics due to their atomic-level thickness, high specific surface area, and tunable physicochemical properties. However, their disordered stacking morphology (common in traditional electrode fabrication processes) creates tortuous ion diffusion paths: ions are forced to bypass the edges of the sheets or traverse narrow interlayer gaps, resulting in a sharp increase in diffusion tortuosity and a significant decrease in the effective diffusion coefficient. This disordered interface severely exacerbates the transport resistance of multivalent ions, becoming a key obstacle limiting the improvement of electrode performance.

[0004] To address these challenges, vertically oriented structure design has emerged. Its core lies in arranging two-dimensional material sheets perpendicular to the current collector surface to construct a linear nanochannel extending directly from the electrode surface to the current collector. This structure significantly shortens the ion diffusion trajectory, reduces the migration energy barrier and tortuosity, and is particularly suitable for rapid transport systems of high charge density ions. Although vertically oriented technologies (such as template methods, mechanical shear force induction, or flow field induction) have shown potential, their industrial application still faces significant limitations: high process complexity, high manufacturing costs, difficulty in controlling orientation, and the risk of introducing potential impurities, making it difficult to meet the demands of large-scale, high-performance electrode manufacturing. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing a positive electrode for a multivalent ion battery based on the vertical orientation of a two-dimensional magnetic material induced by a magnetic field, and its application. This method enables magnesium / aluminum ion batteries to have high energy density, high rate performance, and cycle stability, and can effectively solve the key problems currently faced by multivalent metal ion batteries, such as low energy density, poor rate performance, and poor cycle stability.

[0006] To achieve the above objectives, this invention provides a method for preparing a multivalent ion battery cathode based on the vertical orientation of a two-dimensional magnetic material induced by a magnetic field, comprising the following steps: S1. Magnetic raw materials are mixed and subjected to high-temperature annealing, followed by multiple proton exchange treatments with an acid solution. After filtration, washing, drying, exfoliation in tetramethylammonium hydroxide, and shaking at room temperature, two-dimensional magnetic nanosheets Ti are obtained. 1-x A x O2, x ranges from 0.1 to 0.5, and A is one of Fe, Co, and Ni; S2. Two-dimensional magnetic nanosheets, single-walled carbon nanotubes and polyacrylic acid are dissolved in a solvent in a certain proportion and then ultrasonically treated to obtain a uniform composite slurry. S3. Inject the composite slurry into the rectangular mold of the current collector, and place the permanent magnet below the current collector to generate a rotating magnetic field by rotating the magnet; S4. Under the action of a rotating magnetic field, two-dimensional magnetic materials are induced to achieve vertical orientation self-assembly, and then air-dried under continuous rotating magnetic field conditions to finally obtain a multivalent ion battery cathode with a vertical orientation structure.

[0007] Preferably, the magnetic raw material includes TiO2, K2Co3 and Fe2O3, wherein the stoichiometric ratio of TiO2, K2CO3 and Fe2O3 is a molar ratio of 3-9:1:0.5-1.25; Alternatively, the magnetic raw material may include TiO2, K2CO3 and CoO, wherein the stoichiometric ratio of TiO2, K2CO3 and CoO is a molar ratio of 2.5-4.5:1:0.5-2.5.

[0008] Alternatively, the magnetic raw material may include TiO2, K2CO3 and NiO, wherein the stoichiometric ratio of TiO2, K2CO3 and NiO is a molar ratio of 2.5-4.5:1:0.5-2.5.

[0009] Preferably, in S1, the high-temperature annealing temperature is 700~1100℃, and the annealing time is 12-48h; The concentration of the acid solution was 1-3M, and the protonation treatment time was 48-96h. The number of proton exchange treatments is 2-6, and the interval between two consecutive proton exchange treatments is 12-24 hours. The oscillation frequency is 100-300 rpm; the oscillation time is 6-10 days. Air dry naturally for 12-24 hours.

[0010] Preferably, the solvent is isopropanol, N-methylpyrrolidone, or anhydrous ethanol.

[0011] Preferably, the mass ratio of the two-dimensional magnetic material, single-walled carbon nanotubes, and polyacrylic acid is 8:1:1.

[0012] Preferably, polyacrylic acid can also be replaced with polyvinylidene fluoride or polytetrafluoroethylene.

[0013] A vertically oriented multivalent ion battery cathode, comprising a magnesium and aluminum ion multivalent metal battery cathode.

[0014] An ion battery includes a positive electrode and a negative electrode, wherein the positive electrode is the vertically oriented multivalent ion battery positive electrode as described in claim 8.

[0015] Therefore, the present invention employs the above-mentioned method for preparing a multivalent ion battery cathode based on the vertical orientation of two-dimensional magnetic materials induced by a magnetic field, and its application yields the following technical advantages: The multivalent ion battery cathode prepared in this application, based on the vertical orientation of a two-dimensional magnetic material induced by a magnetic field, can shorten the ion transport path and reduce the ion migration energy barrier when used as a cathode in magnesium and aluminum ion batteries, thereby improving the Mg / Ti ratio. 0.6 Fe 0.4 O2 and Al / Ti 0.6 Fe 0.4 O2 batteries, with their rate performance, energy density, and cycle stability, have significant application prospects in energy-related fields.

[0016] This application presents a multivalent ion battery cathode constructed using a magnetic field-induced vertical alignment technique for two-dimensional magnetic materials, exhibiting superior electrochemical performance. The assembled Mg / Ti... 0.6 Fe 0.4 O2 and Al / Ti 0.6 Fe 0.4 The O2 battery achieved 18.2 kWkg. -1 and 15.7 kW kg -1 Its ultra-high power density is nearly two orders of magnitude higher than that of the most advanced multivalent ion batteries currently available. Furthermore, at 10 A g... -1 Even at ultra-high current densities, magnesium-ion and aluminum-ion batteries still maintain 208 mAh g⁻¹. -1 With 100 mAhg -1 The battery exhibits high specific capacity. It maintains stable high energy density output over a wide temperature range of -30℃ to 50℃, fully demonstrating the enormous potential of vertically oriented cathode structures in practical applications and providing an effective solution for the further development of magnesium and aluminum-ion batteries. Attached Figure Description

[0017] Figure 1 The layered titanate K obtained in Example 1 0.8 Ti 1.2 Fe 0.8 X-ray diffraction (XRD) pattern, scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS) pattern of O4 precursor; Figure 1 (a) The layered titanate K obtained in Example 1 0.8Ti 1.2 Fe 0.8 X-ray diffraction (XRD) pattern of the O4 precursor; Figure 1 (b) The layered titanate K obtained in Example 1 0.8 Ti 1.2 Fe 0.8 Scanning electron microscopy (SEM) of O4 precursor; Figure 1 (c) The layered titanate K obtained in Example 1 0.8 Ti 1.2 Fe 0.8 Energy dispersive X-ray spectrum (EDS) of O4 precursor; Figure 1 (d) is the layered titanate K obtained in Example 1. 0.8 Ti 1.2 Fe 0.8 Mapping diagram of Ti, K, O, and Fe elements in the O4 precursor; Figure 2 Ti obtained in Example 1 0.6 Fe 0.4 XRD pattern of O2 nanosheets; Figure 3 Ti obtained in Example 1 0.6 Fe 0.4 Atomic force microscopy image of O2 nanosheets; Figure 4 Ti obtained in Example 1 0.6 Fe 0.4 O2 nanosheet mapping diagram; Figure 4 (a) Ti obtained in Example 1 0.6 Fe 0.4 Elemental mapping diagram of O2 nanosheets; Figure 4 (b) Ti obtained in Example 1 0.6 Fe 0.4 Mapping diagram of Ti element in O2 nanosheets; Figure 4 (c) Ti obtained in Example 1 0.6 Fe 0.4 Mapping diagram of O element in O2 nanosheets; Figure 4 (d) is the Ti obtained in Example 1. 0.6 Fe 0.4 Mapping diagram of Fe element in O2 nanosheets; Figure 5 The magnetic performance test curve obtained in Example 1; Figure 6 The vertically oriented Ti obtained in Example 1 0.6 Fe 0.4 O2 nanosheet scanning electron microscope (SEM) image; Figure 7 The Mg / Ti obtained in Example 1 0.4 Fe 0.6 O2 and Al / Ti 0.4 Fe 0.6 O2 battery rate performance test chart; Figure 7 (a) Mg / Ti obtained in Example 1 0.4 Fe 0.6 O2 battery rate performance test chart; Figure 7 (b) Al / Ti obtained in Example 1 0.4 Fe 0.6 O2 battery rate performance test chart; Figure 8 The Mg / Ti obtained in Example 1 0.4 Fe 0.6 O2 and Al / Ti 0.4 Fe 0.6 O2 battery cycle stability test chart; Figure 8 (a) Mg / Ti obtained in Example 1 0.4 Fe 0.6 O2 battery cycle stability test chart; Figure 8 (b) Al / Ti obtained in Example 1 0.4 Fe 0.6 O2 battery cycle stability test chart; Figure 9 The Mg / Ti obtained in Example 1 0.4 Fe 0.6 O2 and Al / Ti 0.4 Fe 0.6 Stability test results of O2 batteries at -30℃ and 50℃. Detailed Implementation

[0018] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0020] Example 1 A method for preparing a multivalent ion battery cathode based on the vertical orientation of a two-dimensional magnetic material induced by a magnetic field includes the following steps: S1, Ti 0.6 Fe 0.4 Preparation of O2 nanosheets: S11, K 0.8 Ti 1.2 Fe 0.8Synthesis of O4 precursor. 3 mol TiO2, 1 mol K2Co3, and 1 mol Fe2O3 were weighed, mixed thoroughly, and placed in a platinum crucible. The mixture was then heated to the target annealing temperature (1000℃) in air at a rate of 5℃ / min and held at that temperature for 20 h. After cooling to room temperature, K4 precursor was prepared. 0.8 Ti 1.2 Fe 0.8 O4 precursor.

[0021] S12, K 0.8 Ti 1.2 Fe 0.8 O4 exfoliation to prepare magnetic Ti 0.6 Fe 0.4 O2 monolayer nanosheets. The above layered titanate K... 0.8 Ti 1.2 Fe 0.8 The O4 precursor was subjected to proton exchange treatment with hydrochloric acid (1M) solution at room temperature for 72 h, converting it into the protonated form H. 0.8 Ti 1.2 Fe 0.8 O4•H2O. This process was repeated three times, with the hydrochloric acid solution replaced every 24 hours. The product was then collected by filtration, washed with copious amounts of water and ethanol, and dried at 60°C for 24 hours. The above protonated H2O... 0.8 Ti 1.2 Fe 0.8 O4•H2O was dispersed in a 25 wt% tetramethylammonium hydroxide (TMAOH) solution for intercalation and exfoliation treatment, followed by oscillation at 140 rpm for 7 days at room temperature to prepare a monolayer two-dimensional magnetic Ti. 0.6 Fe 0.4 O2 nanosheets.

[0022] S2. Weigh out 8 portions of Ti according to their mass fractions. 0.6 Fe 0.4 O2 nanosheets, 1 part single-walled carbon nanotubes and 1 part polyacrylic acid were added to isopropanol and sonicated for 30 min to obtain a uniform composite slurry. S3. Place the composite slurry in a rectangular mold with titanium foil as the current collector, and place the neodymium iron boron permanent magnet below the current collector. A rotating magnetic field is generated by rotating the magnet. S4. Under the influence of a magnetic field, two-dimensional magnetic materials are induced to achieve vertically oriented self-assembly, and then naturally air-dried for 12 hours under a continuous rotating magnetic field, finally obtaining a multivalent ion battery cathode Ti with a vertically oriented structure. 0.6 Fe 0.4 O2.

[0023] Mg / Ti 0.6 Fe 0.4 O2 and Al / Ti 0.6Fe 0.4 O2 battery assembly and electrochemical performance testing: The vertically oriented Ti obtained in Example 2 0.6 Fe 0.4 O2 nanosheet cathodes were assembled with commercial magnesium and aluminum metal anodes, separators, and electrolytes to form magnesium-aluminum ion batteries. Constant current charge-discharge tests were performed using a Blue Electric testing system to evaluate key electrochemical performance indicators such as rate performance and cycle stability of the assembled batteries.

[0024] Example 2 Ti in Example 1 0.6 Fe 0.4 O2 nanosheets replaced with Ti 0.9 Fe 0.1 O2 nanosheets, correspondingly, step S1 is replaced with Ti 0.9 Fe 0.1 The preparation steps for O2 nanosheets are the same as in Example 1.

[0025] S1, Ti 0.9 Fe 0.1 Preparation of O2 nanosheets: S11, K 0.8 Ti 1.8 Fe 0.2 Synthesis of O4 precursor. 9 mol TiO2, 1 mol K2Co3, and 0.5 mol Fe2O3 were weighed, mixed thoroughly, and placed in a platinum crucible. The mixture was then heated to the target annealing temperature (1000℃) in air at a rate of 5℃ / min and held for 20 h. After cooling to room temperature, K4 precursor was prepared. 0.8 Ti 1.8 Fe 0.2 O4 precursor.

[0026] S12, K 0.8 Ti 1.8 Fe 0.2 O4 exfoliation to prepare magnetic Ti 0.9 Fe 0.1 O2 monolayer nanosheets. The above layered titanate K... 0.8 Ti 1.8 Fe 0.2 The O4 precursor was subjected to proton exchange treatment with hydrochloric acid (1M) solution at room temperature for 72 h, converting it into the protonated form H. 0.8 Ti 1.8 Fe 0.2 O4•H2O. This process was repeated three times, with the hydrochloric acid solution replaced every 24 hours. The product was then collected by filtration, washed with copious amounts of water and ethanol, and dried at 60°C for 24 hours. The above protonated H2O... 0.8 Ti 1.8 Fe0.2 O4•H2O was dispersed in a 25 wt% tetramethylammonium hydroxide (TMAOH) solution for intercalation and exfoliation treatment, followed by oscillation at 140 rpm for 7 days at room temperature to prepare a monolayer two-dimensional magnetic Ti. 0.9 Fe 0.1 O2 nanosheets.

[0027] Example 3 Ti in Example 1 0.6 Fe 0.4 O2 nanosheets replaced with Ti 0.5 Fe 0.5 O2 nanosheets, correspondingly, step S1 is replaced with Ti 0.5 Fe 0.5 The preparation steps for O2 nanosheets are the same as in Example 1.

[0028] S1, Ti 0.5 Fe 0.5 Preparation of O2 nanosheets: S11, K 0.8 Ti 1.0 Fe 1.0 Synthesis of O4 precursor. 2.5 mol TiO2, 1 mol K2Co3, and 1.25 mol Fe2O3 were weighed, mixed thoroughly, and placed in a platinum crucible. The mixture was then heated to the target annealing temperature (1000℃) in air at a rate of 5℃ / min and held at that temperature for 20 h. After cooling to room temperature, K4 precursor was prepared. 0.8 Ti 1.0 Fe 1.0 O4 precursor.

[0029] S12, K 0.8 Ti 1.0 Fe 1.0 O4 exfoliation to prepare magnetic Ti 0.5 Fe 0.5 O2 monolayer nanosheets. The above layered titanate K... 0.8 Ti 1.0 Fe 1.0 The O4 precursor was subjected to proton exchange treatment with hydrochloric acid (1M) solution at room temperature for 72 h, converting it into the protonated form H. 0.8 Ti 1.0 Fe 1.0 O4•H2O. This process was repeated three times, with the hydrochloric acid solution replaced every 24 hours. The product was then collected by filtration, washed with copious amounts of water and ethanol, and dried at 60°C for 24 hours. The above protonated H2O... 0.8 Ti 1.0 Fe 1.0O4•H2O was dispersed in a 25 wt% tetramethylammonium hydroxide (TMAOH) solution for intercalation and exfoliation treatment, followed by oscillation at 140 rpm for 7 days at room temperature to prepare a monolayer two-dimensional magnetic Ti. 0.5 Fe 0.5 O2 nanosheets.

[0030] Example 4 Ti in Example 1 0.6 Fe 0.4 O2 nanosheets replaced with Ti 0.6 Co 0.4 O2 nanosheets, correspondingly, step S1 is replaced with Ti 0.6 Co 0.4 The preparation steps for O2 nanosheets are the same as in Example 1.

[0031] S1, Ti 0.6 Co 0.4 Preparation of O2 nanosheets: S11, K 0.8 Ti 1.2 Co 0.8 Synthesis of O4 precursor. 3 mol TiO2, 1 mol K2CO3, and 2 mol CoO were weighed, mixed thoroughly, and placed in a platinum crucible. The mixture was then heated to the target annealing temperature (1000℃) in air at a rate of 5℃ / min and held at that temperature for 20 h. After cooling to room temperature, K4 precursor was prepared. 0.8 Ti 1.2 Co 0.8 O4 precursor.

[0032] S12, K 0.8 Ti 1.2 Co 0.8 O4 exfoliation to prepare magnetic Ti 0.6 Co 0.4 O2 monolayer nanosheets. The above layered titanate K... 0.8 Ti 1.2 Co 0.8 The O4 precursor was subjected to proton exchange treatment with hydrochloric acid (1M) solution at room temperature for 72 h, converting it into the protonated form H. 0.8 Ti 1.2 Co 0.8 O4•H2O. This process was repeated three times, with the hydrochloric acid solution replaced every 24 hours. The product was then collected by filtration, washed with copious amounts of water and ethanol, and dried at 60°C for 24 hours. The above protonated H2O... 0.8 Ti 1.2 Co 0.8O4•H2O was dispersed in a 25 wt% tetramethylammonium hydroxide (TMAOH) solution for intercalation and exfoliation treatment, followed by oscillation at 140 rpm for 7 days at room temperature to prepare a monolayer two-dimensional magnetic Ti. 0.6 Co 0.4 O2 nanosheets.

[0033] Example 5 Ti in Example 1 0.6 Fe 0.4 O2 nanosheets replaced with Ti 0.9 Co 0.1 O2 nanosheets, correspondingly, step S1 is replaced with Ti 0.9 Co 0.1 The preparation steps for O2 nanosheets are the same as in Example 1.

[0034] S1, Ti 0.9 Co 0.1 Preparation of O2 nanosheets: S11, K 0.8 Ti 1.8 Co 0.2 Synthesis of O4 precursor. 4.5 mol TiO2, 1 mol K2CO3, and 0.5 mol CoO were weighed, mixed thoroughly, and placed in a platinum crucible. The mixture was then heated to the target annealing temperature (1000℃) in air at a rate of 5℃ / min and held at that temperature for 20 h. After cooling to room temperature, K4 precursor was prepared. 0.8 Ti 1.8 Co 0.2 O4 precursor.

[0035] S12, K 0.8 Ti 1.8 Co 0.2 O4 exfoliation to prepare magnetic Ti 0.9 Co 0.1 O2 monolayer nanosheets. The above layered titanate K... 0.8 Ti 1.8 Co 0.2 The O4 precursor was subjected to proton exchange treatment with hydrochloric acid (1M) solution at room temperature for 72 h, converting it into the protonated form H. 0.8 Ti 1.8 Co 0.2 O4•H2O. This process was repeated three times, with the hydrochloric acid solution replaced every 24 hours. The product was then collected by filtration, washed with copious amounts of water and ethanol, and dried at 60°C for 24 hours. The above protonated H2O... 0.8 Ti 1.8 Co 0.2O4•H2O was dispersed in a 25 wt% tetramethylammonium hydroxide (TMAOH) solution for intercalation and exfoliation treatment, followed by oscillation at 140 rpm for 7 days at room temperature to prepare a monolayer two-dimensional magnetic Ti. 0.9 Co 0.1 O2 nanosheets.

[0036] Example 6 Ti in Example 1 0.6 Fe 0.4 O2 nanosheets replaced with Ti 0.5 Co 0.5 O2 nanosheets, correspondingly, step S1 is replaced with Ti 0.5 Co 0.5 The preparation steps for O2 nanosheets are the same as in Example 1.

[0037] S1, Ti 0.5 Co 0.5 Preparation of O2 nanosheets: S11, K 0.8 Ti 1.0 Co 1.0 Synthesis of O4 precursor. 2.5 mol TiO2, 1 mol K2CO3, and 2.5 mol CoO were weighed, mixed thoroughly, and placed in a platinum crucible. The mixture was then heated to the target annealing temperature (1000℃) in air at a rate of 5℃ / min and held for 20 h. After cooling to room temperature, K4 precursor was prepared. 0.8 Ti 1.0 Co 1.0 O4 precursor.

[0038] S12, K 0.8 Ti 1.0 Co 1.0 O4 exfoliation to prepare magnetic Ti 0.5 Co 0.5 O2 monolayer nanosheets. The above layered titanate K... 0.8 Ti 1.0 Co 1.0 The O4 precursor was subjected to proton exchange treatment with hydrochloric acid (1M) solution at room temperature for 72 h, converting it into the protonated form H. 0.8 Ti 1.0 Co 1.0 O4•H2O. This process was repeated three times, with the hydrochloric acid solution replaced every 24 hours. The product was then collected by filtration, washed with copious amounts of water and ethanol, and dried at 60°C for 24 hours. The above protonated H2O... 0.8 Ti 1.0 Co 1.0O4•H2O was dispersed in a 25 wt% tetramethylammonium hydroxide (TMAOH) solution for intercalation and exfoliation treatment, followed by oscillation at 140 rpm for 7 days at room temperature to prepare a monolayer two-dimensional magnetic Ti. 0.5 Co 0.5 O2 nanosheets.

[0039] Example 7 Ti in Example 1 0.6 Fe 0.4 O2 nanosheets replaced with Ti 0.5 Ni 0.5 O2 nanosheets, correspondingly, step S1 is replaced with Ti 0.5 Ni 0.5 The preparation steps for O2 nanosheets are the same as in Example 1.

[0040] S1, Ti 0.5 Ni 0.5 Preparation of O2 nanosheets: S11, K 0.8 Ti 1.0 Ni 1.0 Synthesis of O4 precursor. 2.5 mol TiO2, 1 mol K2CO3, and 2.5 mol NiO were weighed, mixed thoroughly, and placed in a platinum crucible. The mixture was then heated to the target annealing temperature (1000℃) in air at a rate of 5℃ / min and held at that temperature for 20 h. After cooling to room temperature, K4 precursor was prepared. 0.8 Ti 1.0 Ni 1.0 O4 precursor.

[0041] S12, K 0.8 Ti 1.0 Ni 1.0 O4 exfoliation to prepare magnetic Ti 0.5 Ni 0.5 O2 monolayer nanosheets. The above layered titanate K... 0.8 Ti 1.0 Ni 1.0 The O4 precursor was subjected to proton exchange treatment with hydrochloric acid (1M) solution at room temperature for 72 h, converting it into the protonated form H. 0.8 Ti 1.0 Ni 1.0 O4•H2O. This process was repeated three times, with the hydrochloric acid solution replaced every 24 hours. The product was then collected by filtration, washed with copious amounts of water and ethanol, and dried at 60°C for 24 hours. The above protonated H2O... 0.8 Ti 1.0 Ni 1.0O4•H2O was dispersed in a 25 wt% tetramethylammonium hydroxide (TMAOH) solution for intercalation and exfoliation treatment, followed by oscillation at 140 rpm for 7 days at room temperature to prepare a monolayer two-dimensional magnetic Ti. 0.5 Ni 0.5 O2 nanosheets.

[0042] Example 8 Ti in Example 1 0.6 Fe 0.4 O2 nanosheets replaced with Ti 0.6 Ni 0.4 O2 nanosheets, correspondingly, step S1 is replaced with Ti 0.6 Ni 0.4 The preparation steps for O2 nanosheets are the same as in Example 1.

[0043] S1, Ti 0.6 Ni 0.4 Preparation of O2 nanosheets: S11, K 0.8 Ti 1.2 Ni 0.8 Synthesis of O4 precursor. 3 mol TiO2, 1 mol K2CO3, and 2 mol NiO were weighed, mixed thoroughly, and placed in a platinum crucible. The mixture was then heated to the target annealing temperature (1000℃) in air at a rate of 5℃ / min and held at that temperature for 20 h. After cooling to room temperature, K4 precursor was prepared. 0.8 Ti 1.2 Ni 0.8 O4 precursor.

[0044] S12, K 0.8 Ti 1.2 Ni 0.8 O4 exfoliation to prepare magnetic Ti 0.6 Ni 0.4 O2 monolayer nanosheets. The above layered titanate K... 0.8 Ti 1.2 Ni 0.8 The O4 precursor was subjected to proton exchange treatment with hydrochloric acid (1M) solution at room temperature for 72 h, converting it into the protonated form H. 0.8 Ti 1.2 Ni 0.8 O4•H2O. This process was repeated three times, with the hydrochloric acid solution replaced every 24 hours. The product was then collected by filtration, washed with copious amounts of water and ethanol, and dried at 60°C for 24 hours. The above protonated H2O... 0.8 Ti 1.2 Ni 0.8O4•H2O was dispersed in a 25 wt% tetramethylammonium hydroxide (TMAOH) solution for intercalation and exfoliation treatment, followed by oscillation at 140 rpm for 7 days at room temperature to prepare a monolayer two-dimensional magnetic Ti. 0.6 Ni 0.4 O2 nanosheets.

[0045] Example 9 Ti in Example 1 0.6 Fe 0.4 O2 nanosheets replaced with Ti 0.9 Ni 0.1 O2 nanosheets, correspondingly, step S1 is replaced with Ti 0.9 Ni 0.1 The preparation steps for O2 nanosheets are the same as in Example 1.

[0046] S1, Ti 0.9 Ni 0.1 Preparation of O2 nanosheets: S11, K 0.8 Ti 1.8 Ni 0.2 Synthesis of O4 precursor. 4.5 mol TiO2, 1 mol K2CO3, and 0.5 mol NiO were weighed, mixed thoroughly, and placed in a platinum crucible. The mixture was then heated to the target annealing temperature (1000℃) in air at a rate of 5℃ / min and held at that temperature for 20 h. After cooling to room temperature, K4 precursor was prepared. 0.8 Ti 1.8 Ni 0.2 O4 precursor.

[0047] S12, K 0.8 Ti 1.8 Ni 0.2 O4 exfoliation to prepare magnetic Ti 0.9 Ni 0.1 O2 monolayer nanosheets. The above layered titanate K... 0.8 Ti 1.8 Ni 0.2 The O4 precursor was subjected to proton exchange treatment with hydrochloric acid (1M) solution at room temperature for 72 h, converting it into the protonated form H. 0.8 Ti 1.8 Ni 0.2 O4•H2O. This process was repeated three times, with the hydrochloric acid solution replaced every 24 hours. The product was then collected by filtration, washed with copious amounts of water and ethanol, and dried at 60°C for 24 hours. The above protonated H2O... 0.8 Ti 1.8 Ni 0.2O4•H2O was dispersed in a 25 wt% tetramethylammonium hydroxide (TMAOH) solution for intercalation and exfoliation treatment, followed by oscillation at 140 rpm for 7 days at room temperature to prepare a monolayer two-dimensional magnetic Ti. 0.9 Ni 0.1 O2 nanosheets.

[0048] Figure 1 The layered titanate K obtained in Example 1 0.8 Ti 1.2 Fe 0.8 X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) patterns of the O4 precursor, K 0.8 Ti 1.2 Fe 0.8 O4 exhibits strong crystallinity, lacks impurity peaks, and displays a blocky structure with uniform element distribution, indicating that K 0.8 Ti 1.2 Fe 0.8 O4 precursor was successfully prepared; Figure 2 Ti obtained in Example 1 0.6 Fe 0.4 XRD patterns of O2 nanosheets, compared to K 0.8 Ti 1.2 Fe 0.8 O4 precursor, Ti 0.6 Fe 0.4 The characteristic peak of O2 changed significantly, and the crystal planes (020) and (040) shifted at small angles, indicating that K 0.8 Ti 1.2 Fe 0.8 The bulk cell parameters of O4 have changed significantly; Figure 3 Ti obtained in Example 1 0.6 Fe 0.4 The atomic force microscopy image of the O2 nanosheets shows that the nanosheets exhibit a distinct sheet-like structure with a thickness of approximately 1.1 nanometers, which contrasts sharply with the bulk structure of the precursor, further demonstrating the presence of Ti. 0.6 Fe 0.4 O2 nanosheets were successfully exfoliated and prepared. Figure 4 Ti obtained in Example 1 0.6 Fe 0.4 The O2 nanosheet mapping diagram shows that Ti, Te, and O elements are evenly distributed. Figure 5 The figure shows the magnetic performance test curves obtained in Example 1. As can be seen from the figure, Ti 0.6 Fe 0.4 The O2 nanosheets exhibit a distinct hysteresis loop, indicating that the nanosheets possess stable room-temperature ferromagnetism. Figure 6 The vertically oriented Ti obtained in Example 20.6 Fe 0.4 The image shows a scanning electron microscope (SEM) image of O2 nanosheets, from which we can see that Ti... 0.6 Fe 0.4 The uniform vertical orientation of the O2 nanosheets indicates that an externally applied flipping magnetic field can effectively induce the orientation structure of magnetic nanomaterials. Figure 7 The Mg / Ti obtained in Example 3 0.6 Fe 0.4 O2 and Al / Ti 0.6 Fe 0.4 The O2 battery rate performance test results show that, compared with the horizontally oriented structure, the vertically oriented nanosheets used as the cathode of magnesium-ion and aluminum-ion batteries significantly improve the specific capacity and rate performance. This indicates that the vertically oriented structure can effectively shorten the ion migration path, thereby accelerating the storage dynamics and improving the storage capacity. Figure 8 The Mg / Ti obtained in Example 3 0.6 Fe 0.4 O2 and Al / Ti 0.4 Fe 0.6 The O2 battery cycle stability test, as shown in the figure, indicates that the vertical orientation structure can effectively improve the cycle stability of magnesium and aluminum ion batteries. Figure 9 The Mg / Ti obtained in Example 3 0.6 Fe 0.4 O2 and Al / Ti 0.6 Fe 0.4 The stability tests of the O2 battery at -30℃ and 50℃ are shown in the figure. As can be seen, this vertically oriented electrode structure enables the magnesium-aluminum ion battery to operate stably at high capacity over a wide temperature range, further demonstrating the rapid ion transport kinetics of the vertically oriented structure. Simultaneously, the vertically oriented Ti… 0.6 Fe 0.4 O2 cathodes have strong application prospects in magnesium and aluminum ion batteries.

[0049] Therefore, the present invention adopts the above-mentioned method for preparing a multivalent ion battery cathode based on the vertical orientation of two-dimensional magnetic materials induced by a magnetic field and its application. The magnesium / aluminum ion battery has high energy density, high rate performance and cycle stability, which can effectively solve the key problems faced by current multivalent metal ion batteries, such as low energy density, poor rate performance and poor cycle stability.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for preparing a positive electrode of a multivalent ion battery based on vertical orientation of a two-dimensional magnetic material induced by a magnetic field, the method comprising: preparing a two-dimensional magnetic material; and applying a magnetic field to the two-dimensional magnetic material to induce vertical orientation of the two-dimensional magnetic material. Includes the following steps: S1, the magnetic raw materials are mixed, high-temperature annealing treatment is performed, then multiple proton exchange treatments are performed with an acid solution, then filtration, washing and drying are performed, stripping is performed in tetramethylammonium hydroxide, and two-dimensional magnetic nanosheets Ti 1-x A x O2, x ranges from 0.1 to 0.5, and A is one of Fe, Co and Ni. S2. Two-dimensional magnetic nanosheets, single-walled carbon nanotubes and polyacrylic acid are dissolved in a solvent in a certain proportion and then ultrasonically treated to obtain a uniform composite slurry. S3. Inject the composite slurry into the rectangular mold of the current collector, and place the permanent magnet below the current collector to generate a rotating magnetic field by rotating the magnet; S4. Under the action of a rotating magnetic field, two-dimensional magnetic materials are induced to achieve vertical orientation self-assembly, and then air-dried under continuous rotating magnetic field conditions to finally obtain a multivalent ion battery cathode with a vertical orientation structure.

2. The method for preparing a multi-valence ion battery cathode based on the vertical orientation of a magnetic field-induced two-dimensional magnetic material according to claim 1, characterized in that, The magnetic raw materials include TiO2, K2Co3 and Fe2O3, wherein the stoichiometric ratio of TiO2, K2Co3 and Fe2O3 is a molar ratio of 3-9:1:0.5-1.25; Alternatively, the magnetic material may include TiO2, K2CO3, and CoO, wherein the stoichiometric ratio of TiO2, K2CO3, and CoO is a molar ratio of 2.5-4.5:1:0.5-2.5; Alternatively, the magnetic raw material may include TiO2, K2CO3 and NiO, wherein the stoichiometric ratio of TiO2, K2CO3 and NiO is a molar ratio of 2.5-4.5:1:0.5-2.

5.

3. The method for preparing a multivalent ion battery cathode based on the vertical orientation of a two-dimensional magnetic material induced by a magnetic field, as described in claim 1, is characterized in that... In S1, the high-temperature annealing temperature is 700~1100℃, and the annealing time is 12-48h; The concentration of the acid solution was 1-3M, and the protonation treatment time was 48-96h. The number of proton exchange treatments is 2-6, and the interval between two consecutive proton exchange treatments is 12-24 hours. The oscillation frequency is 100-300 rpm; the oscillation time is 6-10 days. Air dry naturally for 12-24 hours.

4. The method for preparing a multivalent ion battery cathode based on the vertical orientation of a two-dimensional magnetic material induced by a magnetic field, as described in claim 1, is characterized in that... The solvent is isopropanol, N-methylpyrrolidone, or anhydrous ethanol.

5. The method for preparing a multivalent ion battery cathode based on the vertical orientation of a two-dimensional magnetic material induced by a magnetic field, as described in claim 1, is characterized in that... The mass ratio of the two-dimensional magnetic material, single-walled carbon nanotubes, and polyacrylic acid is 8:1:

1.

6. The method for preparing a multivalent ion battery cathode based on the vertical orientation of a two-dimensional magnetic material induced by a magnetic field, as described in claim 1, is characterized in that... Polyacrylic acid can also be replaced with polyvinylidene fluoride or polytetrafluoroethylene.

7. A vertically oriented multivalent ion battery cathode prepared using the method for preparing a multivalent ion battery cathode based on the vertical orientation of a two-dimensional magnetic material induced by a magnetic field as described in any one of claims 1-6, characterized in that, Including magnesium and aluminum ion multivalent metal battery cathodes.

8. An ion battery, characterized in that, It includes a positive electrode and a negative electrode, wherein the positive electrode is the vertically oriented multivalent ion battery positive electrode as described in claim 7.

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