Latp-derived lithium ion sieve material, and preparation method and application thereof
By preparing the LATP-derived lithium-ion sieve material H1+xAlxTi2-x(PO4)3, the problems of stability and adsorption rate of existing lithium-ion sieve materials in acidic environments were solved, enabling rapid adsorption and elution of lithium ions and improving lithium-ion extraction efficiency and selectivity.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA UNIV OF GEOSCIENCES (WUHAN)
- Filing Date
- 2026-01-14
- Publication Date
- 2026-05-29
AI Technical Summary
Existing lithium-ion sieve materials exhibit poor chemical stability, slow adsorption rate, and low adsorption capacity in acidic environments, making it difficult to meet industrial requirements.
HATP was prepared by using LATP-derived lithium-ion sieve material H1+xAlxTi2-x(PO4)3 and acid treatment of LATP powder. Its NASICON structure and three-dimensional channels were utilized to achieve rapid adsorption and elution of lithium ions.
HATP materials exhibit excellent chemical stability in acidic environments, significantly extending their service life. They also enable rapid lithium-ion transport and selective adsorption through three-dimensional channels, improving lithium-ion extraction efficiency and speed.
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Figure CN122102083A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of lithium extraction technology, and in particular to an LATP-derived lithium ion sieve material, its preparation method, and its application. Background Technology
[0002] With the global energy structure shifting towards cleaner and lower-carbon energy, emerging industries such as electric vehicles and portable electronic devices are developing rapidly, leading to an explosive growth in demand for lithium-ion batteries, their core energy storage components. This has directly resulted in a sharp increase in demand for lithium, a key raw material. Currently, global lithium resources mainly come from hard-rock ores (such as spodumene) and continental salt lake brines. However, existing lithium extraction technologies all have significant limitations. Lithium extraction from ores is complex, involving high-temperature roasting and acid-base leaching, which not only consumes enormous amounts of energy but also generates large quantities of tailings and wastewater, placing significant pressure on the environment. Lithium extraction from salt lake brines mainly relies on the traditional solar evaporation and precipitation method. This method uses sunlight and wind power to evaporate the water in the brine, gradually concentrating and precipitating potassium, sodium, magnesium, and other salts to ultimately obtain lithium-rich brine. This method has an extremely long process cycle, typically requiring months or even years, and is strictly limited by geographical location and climate conditions, resulting in low lithium recovery rates. Especially when processing brines with high magnesium / lithium ratios, magnesium-lithium separation has become a global challenge.
[0003] Against this backdrop, adsorption, as an emerging lithium extraction technology, is considered a highly promising alternative due to its advantages such as high selectivity, fast adsorption rate, environmental friendliness, and strong adaptability to lithium solutions with low or high impurity content. Within the adsorption technology system, lithium-ion sieve technology is the core support, and its development level directly affects the overall efficiency and industrial application prospects of adsorption-based lithium extraction.
[0004] Currently, the most widely researched and applied lithium-ion sieves are mainly divided into two categories: manganese-based lithium-ion sieves (LMO type) and titanium-based lithium-ion sieves (LTO type). Manganese-based lithium-ion sieves (such as spinel-type λ-MnO2) have high theoretical adsorption capacity; however, they suffer from significant chemical stability issues. During acidic elution, manganese easily undergoes disproportionation reactions and dissolves (i.e., dissolution loss), leading to material structural collapse and a significantly shortened cycle life. This defect severely restricts their industrial application. Titanium-based lithium-ion sieves (such as H2TiO3), compared to manganese-based materials, exhibit better chemical stability in acidic solutions and a lower dissolution rate. However, titanium-based ion sieves typically face problems such as slow adsorption rates and relatively low adsorption capacities.
[0005] In conclusion, the need to develop high-efficiency lithium-ion sieve materials is clear and urgent. Summary of the Invention
[0006] The purpose of this invention is to address the aforementioned shortcomings of existing technologies by providing an LATP-derived lithium-ion sieve material, its preparation method, and its applications. The LATP-derived lithium-ion sieve material, HATP, has a NASICON structure and its general chemical formula is H. 1+x Al x Ti 2-x (PO4)3, where x is 0.1-0.5. In lithium adsorption and extraction, it can not only withstand the corrosion of acidic eluents, but its unique three-dimensional channels are also conducive to the rapid adsorption and elution of lithium ions.
[0007] Furthermore, x is 0.1, 0.2, 0.3, 0.4, and 0.5.
[0008] A method for preparing LATP-derived lithium-ion sieve material as described above, wherein the lithium-ion sieve material HATP is obtained by acid treatment of LATP powder followed by separation and drying.
[0009] Furthermore, the leaching solution is dilute nitric acid with a concentration of 0.5~1 mol L. -1 .
[0010] Furthermore, the solid-liquid ratio is 2~5 g / L. -1 The acid treatment time is 20~24 h.
[0011] Furthermore, the preparation method of LATP powder is as follows: S1. Weigh out lithium source, aluminum source, titanium source and phosphate according to the chemical dosage ratio of LATP, mix them, wet ball mill and dry to obtain raw material powder; S2. Pre-calcine the raw material powder and cool it to room temperature to obtain the precursor; S3. After grinding the precursor, it is calcined twice and cooled to room temperature to obtain LATP powder.
[0012] Further, in step S1, the lithium source is any one or more of lithium carbonate, lithium hydroxide, or lithium acetate; the aluminum source is one or two of aluminum oxide and aluminum hydroxide; the titanium source is any one or more of rutile phase, anatase phase, or amorphous titanium dioxide; and the phosphate is any one or two of ammonium dihydrogen phosphate or diammonium hydrogen phosphate.
[0013] Furthermore, the lithium source is added in excess by 5% to 10% by mass.
[0014] Further, in step S1, the wet ball milling process is as follows: the ball milling jar is made of corundum, the ball milling beads are zirconia balls, the ball milling medium is isopropanol, the ball milling speed is 450~500 rpm, and the ball milling time is 2~3 h; the drying temperature is 70~75 ℃, and the drying time is 5~6 h.
[0015] Furthermore, in step S2, the pre-calcination temperature is set at 700~750 ℃, and the heating rate is 3~5 ℃ min. -1 The holding time is 4-6 hours; in step S3, the secondary calcination temperature is set at 900-950 ℃, and the heating rate is 3-5 ℃ / min. -1 The heat preservation time is 6~8 hours.
[0016] An application of the LATP-derived lithium-ion sieve material described above is used to adsorb lithium ions in brine.
[0017] Furthermore, the brine is salt lake brine.
[0018] Beneficial effects: This invention innovatively incorporates Li with a NASICON structure 1+x Al x Ti 2-x (PO4)3(LATP) is converted into HATP, a LATP-derived lithium-ion sieve material, through acid leaching and delithiation treatment. HATP inherits the robust NASICON framework of LATP, which not only resists the corrosion of acidic eluents, but also its unique three-dimensional channels facilitate rapid ion transport. This opens up a new system of titanium-based adsorbent materials.
[0019] Benefiting from its rigid phosphate three-dimensional framework, HATP exhibits excellent chemical stability in acidic environments, effectively suppressing dissolution during application and significantly extending its service life. Simultaneously, HATP inherits the unobstructed three-dimensional interconnected ion transport channels of the original LATP, significantly reducing the resistance to lithium-ion diffusion within the material and enabling rapid lithium-ion adsorption and elution, greatly improving lithium-ion extraction efficiency and speed. Based on its precisely designed lattice structure and high vacancy size matching, HATP demonstrates excellent selective lithium-ion adsorption capacity in complex brine systems with high magnesium / lithium ratios.
[0020] The adsorption mechanism of lithium ions by HATP is mainly based on the synergistic effect of ion exchange reaction and ion memory effect. During the adsorption process, Li in the brine... + Driving the deprotonation process, with H in the crystal lattice + Reversible substitution occurs, penetrating the material's interior; thanks to the stable framework formed by the high-temperature sintering of the LATP precursor, the lattice vacancy size left after acid leaching is similar to that of Li. + The radius is highly compatible, and the steric hindrance effect effectively blocks the larger radius Na. + and K + Embedding; at the same time, due to Mg 2+ It has a much higher value than Li +The hydration energy of Li is too high, and the energy barrier for its dehydration into the crystal lattice is too high, thus it is effectively repelled, ultimately achieving the hydration energy of Li. + Precise screening and efficient enrichment. Attached Figure Description
[0021] Figure 1 X-ray diffraction (XRD) patterns of x-LATP samples (x = 0.1, 0.2, 0.3, 0.4, 0.5); Figure 2 XRD pattern of x-HATP sample; Figure 3 SEM images of x-LATP and x-HATP samples; Figure 4 Ti in x-HATP samples 4+ Results of the dissolution test; Figure 5 Results of cyclic adsorption experiments on 0.5-HATP and HTP samples; Figure 6 Selectivity test results for 0.5-HATP samples. Detailed Implementation
[0022] The following are specific embodiments of the present invention, and the technical solutions of the present invention will be further described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.
[0023] Examples 1-5: Preparation of x-HATP (x=0.1, 0.2, 0.3, 0.4, 0.5) lithium-ion sieves This section describes in detail the steps for preparing x-HATP lithium-ion sieves. The preparation of 0.5-HATP is used as an example below. The preparation of other components (x=0.1, 0.2, 0.3, 0.4) follows the same process, with only the raw material ratios adjusted accordingly.
[0024] (1) Raw material ratio: Lithium carbonate (Li2CO3, analytical grade, ≥99.0%), nano aluminum oxide (Al2O3, ≥97.0%), nano titanium dioxide (TiO2, rutile type, ≥99.9%) and ammonium dihydrogen phosphate (NH4H2PO4, analytical grade, ≥99.0%) are used as precursor raw materials.
[0025] In order to synthesize the chemical formula Li 1.5 Al 0.5 Ti 1.5 The target product (PO4)3 is obtained by accurately weighing each raw material according to the stoichiometric ratio. Considering that lithium is prone to volatilization during high-temperature processing, an additional 5% to 10% lithium carbonate is usually added as compensation.
[0026] (2) Mixing and grinding: The precursor raw materials weighed according to the metering ratio were placed in the alumina ball mill jar of a planetary ball mill, and an appropriate amount of isopropanol was added as the ball milling medium to promote uniform mixing of the raw materials. The ball milling speed was set to 400 rpm, and the ball milling time was 2 h. After ball milling, the obtained slurry was transferred to an oven and dried at 80℃ for 24 h to completely remove ethanol.
[0027] (3) Pre-calcination: The dried mixed powder is placed in an alumina crucible and then placed in a muffle furnace for pre-calcination in air atmosphere. The heating rate is 3 °C / min. -1 The temperature is raised to 700℃ and held for 4 hours. The purpose of this step is to decompose the precursors (such as Li2CO3 and NH4H2PO4) and initially react to generate the crystal phase of the target LATP.
[0028] (4) Secondary sintering: The blocky product formed after pre-sintering is taken out, and it is first crushed with an agate mortar and pestle, and then ball milled again. The conditions for secondary ball milling can be set to 400 rpm for 4 h, in order to obtain fine powder with smaller particle size, more uniform distribution and higher reactivity.
[0029] The LATP fine powder obtained after secondary grinding was placed in an alumina crucible and then placed in a high-temperature muffle furnace for sintering in air atmosphere. -1 The temperature was increased to 900°C at a certain rate and held at this temperature for 6 hours to obtain high-purity LATP powder. After sintering, the furnace was allowed to cool naturally to room temperature.
[0030] Using the above method, x-LATP sintered samples with x=0.1, 0.2, 0.3, 0.4, and 0.5 were prepared respectively.
[0031] (5) Acid leaching: The x-LATP powder obtained above is leached at a solid-liquid ratio of 5 g / L. -1 Weigh 0.5 g of x-LATP powder and place it in a 250 mL Erlenmeyer flask. Add 100 mL of 0.5 mol L... -1 The nitric acid solution was placed in a constant temperature water bath with a magnetic stirrer and leached for 24 h. The mixture was then vacuum filtered, washed until neutral, and subsequently dried in a 60°C drying oven for 12 h to obtain x-HATP series powders, which were used for subsequent adsorption tests.
[0032] Material characterization The phase and microstructure of the series of samples prepared in Examples 1-5 were characterized.
[0033] Phase analysis (XRD) was performed on the fine powder of the sintered sample using an X-ray diffractometer.
[0034] Figure 1 The XRD patterns of x-LATP (x=0.1~0.5) samples are shown. As can be seen from the figures, the major diffraction peaks of all samples correspond well to the standard card (JCPDS No. 35-0754) of the rhombohedral crystal system (space group R-3c) of the NASICON type structure. This indicates that the target phase was successfully synthesized by the solid-state method described in this invention. No obvious impurity phases (such as AlPO4 or TiO2) diffraction peaks were observed in the patterns, indicating that the product has high purity.
[0035] Figure 2 The XRD patterns of the x-HATP samples are shown. The (012), (113), and (300) crystal planes from the LTP (PDF#35-0754) standard spectrum are observed in the HATP spectra, all near 2θ = 14.8°, 24.6°, and 36.6°. Furthermore, the main diffraction peaks shift to the left compared to the precursor x-LATP, corresponding to changes in the lattice parameters of the material, indicating that H+ ions were present during the acid leaching process. + Successfully replaced part of the Li in the crystal lattice + .
[0036] Microstructure analysis (SEM) Figure 3 SEM images of x-LATP and x-HATP are shown.
[0037] Figure 3 a, b represent LTP and HTP; c, d represent 0.1-LATP and 0.1-HATP; e, f represent 0.2-LATP and 0.2-HATP; g, h represent 0.3-LATP and 0.3-HATP; i, j represent 0.4-LATP and 0.4-HATP; k, l represent 0.5-LATP and 0.5-HATP.
[0038] from Figure 3 It can be seen that the particle morphology of the samples after Al doping and acid leaching did not change much, and they were all irregular polyhedra. At the same time, it was found that the particles on the precursor surface were mostly adhered together, forming a bulk structure and exhibiting agglomeration. However, the lithium ion sieve particles after acid leaching were more distinct and the particle boundaries were clearer.
[0039] Lithium-ion adsorption performance test and comparison To evaluate the performance of x-HATP materials with different Al doping levels as lithium ion sieves, static adsorption comparison experiments were conducted.
[0040] Accurately weigh 0.5 g of the x-HATP powder obtained in Examples 1-5, and add it to 100 mL of the initial lithium ion concentration (…). C 0) is 1000 mg / L -1The mixture was placed in an aqueous solution of LiOH. The conical flask containing the mixture was placed in a constant temperature water bath with a magnetic stirrer and shaken at 200 rpm for 24 h at 30 °C to ensure that the adsorption process reached equilibrium.
[0041] The same steps were used in the cyclic adsorption experiment.
[0042] In the adsorption selectivity experiment, the concentrations of each cation in the prepared simulated salt lake brine were as follows: Li + 200 mg L -1 Mg 2+ 3000 mg L -1 Na + 7000 mg L -1 K + 5000 mg L -1 Ca 2+ 400 mg L -1 pH=8.4.
[0043] After adsorption is complete, the solid adsorbent is separated from the liquid phase by vacuum filtration.
[0044] Concentration analysis The lithium ion concentration in the filtrate after equilibrium was accurately determined using inductively coupled plasma optical emission spectrometry (ICP-OES). C e ).
[0045] Adsorption capacity calculation The adsorption capacity of each sample under equilibrium conditions is calculated using the following formula ( Q e (Unit: mg / g) Q e = ( C 0- C e ) × V / m in, C 0 represents the initial concentration (1000 mg / L). C e For equilibrium concentration (mg / L) V This is the solution volume (0.1 L). m This refers to the mass of the adsorbent (0.5 g).
[0046] Results and Comparisons As shown in Table 1, the adsorption capacity increases with the value of x from 0.1 to 0.5; the adsorption capacity reaches its peak when x = 0.5. Therefore, it can be concluded that under the tested conditions, the chemical formula H...1.5 Al 0.5 Ti 1.5 The 0.5-HATP material of (PO4)3 is the best-performing lithium-ion sieve. Example 5 showed the highest adsorption capacity, reaching 21.99 mg·g. -1 The adsorption capacity of the HTP lithium ion sieve (10.25 mg·g⁻¹) was compared with that of the comparative example. -1 Compared to the previous year, this represents an increase of 114.5%.
[0047] Table 1. Adsorption capacity of the examples and comparative examples
[0048] Figure 4 Ti for x-HATP samples 4+ Dissolution loss. Ti in 0.5-HATP sample 4+ The lowest solubility indicates good stability.
[0049] Figure 5 Cyclic adsorption experiments of 0.5-HATP and HTP samples. During the cycling process, HTP and 0.5-HATP exhibited varying adsorption properties on Li. + The adsorption capacities of HTP and 0.5-HATP decreased slowly. After four adsorption-desorption cycles, the adsorption capacities of HTP and 0.5-HATP on Li... + The adsorption capacities were still 90.5% and 92.3% of the initial adsorption capacities, respectively. This indicates that HTP and 0.5-HATP have good cycling performance.
[0050] Figure 6 Selectivity experiment of 0.5-HATP sample. In a prepared simulated salt lake brine (pH=8.4), its selectivity for Li... + It has good selectivity.
[0051] analyze Figure 5 and Figure 6 The conclusion is that the sample in Example 5 (0.5-HATP) has good cycling stability and adsorption selectivity.
[0052] For any points not covered above, existing technologies shall apply.
[0053] Although specific embodiments of the present invention have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of the invention. Those skilled in the art can make various modifications or additions to the described specific embodiments or use similar methods to replace them, without departing from the direction of the invention or exceeding the scope defined by the appended claims. Those skilled in the art should understand that any modifications, equivalent substitutions, improvements, etc., made to the above embodiments based on the technical essence of the present invention should be included within the protection scope of the present invention.
Claims
1. A LATP-derived lithium-ion sieve material, characterized in that, The LATP-derived lithium-ion sieve material HATP has a NASICON structure and its general chemical formula is H. 1+x Al x Ti 2-x (PO4)3, where x is 0.1-0.
5.
2. The LATP-derived lithium-ion sieve material as described in claim 1, characterized in that, x is 0.1, 0.2, 0.3, 0.4, and 0.
5.
3. A method for preparing the LATP-derived lithium-ion sieve material as described in claim 1, characterized in that, The LATP-derived lithium-ion sieve material HATP is obtained by separating and drying LATP powder after acid treatment.
4. The preparation method according to claim 3, characterized in that, The acid leaching solution is dilute nitric acid with a concentration of 0.5~1 mol / L. -1 .
5. The preparation method according to claim 3, characterized in that, The solid-liquid ratio for acid treatment is 2-5 g / L. -1 The acid treatment time is 20~24 h.
6. The preparation method according to claim 3, characterized in that, The preparation method of LATP powder is as follows: S1. Weigh out lithium source, aluminum source, titanium source and phosphate according to the chemical dosage ratio of LATP, mix them, wet ball mill and dry to obtain raw material powder; S2. Pre-calcine the raw material powder and cool it to room temperature to obtain the precursor; S3. After grinding the precursor, it is calcined twice and cooled to room temperature to obtain LATP powder.
7. The preparation method according to claim 6, characterized in that, In step S1, the lithium source is any one or more of lithium carbonate, lithium hydroxide, or lithium acetate; the aluminum source is one or two of aluminum oxide and aluminum hydroxide; the titanium source is any one or more of rutile phase, anatase phase, or amorphous titanium dioxide; and the phosphate is any one or two of ammonium dihydrogen phosphate or diammonium hydrogen phosphate.
8. The preparation method according to claim 6, characterized in that, The lithium source is added in excess of 5% to 10% by mass; In step S1, the wet ball milling process is as follows: the ball milling jar is made of corundum, the ball milling beads are zirconia balls, the ball milling medium is isopropanol, the ball milling speed is 450~500 rpm, and the ball milling time is 2~3 h; the drying temperature is 70~75 ℃, and the drying time is 5~6 h. In step S2, the pre-calcination temperature is set at 700~750 ℃, and the heating rate is 3~5 ℃ min. -1 The holding time is 4-6 hours; in step S3, the secondary calcination temperature is set at 900-950 ℃, and the heating rate is 3-5 ℃ / min. -1 The heat preservation time is 6~8 hours.
9. An application of the LATP-derived lithium-ion sieve material as described in claim 1, characterized in that, Used to adsorb lithium ions in brine.
10. The application as described in claim 9, characterized in that, The brine is salt lake brine.