Thiocyanate-doped modified anti-perovskite material, and preparation method and application thereof

Abstract

The invention discloses an anti-perovskite material. In particular to a thiocyanate-doped modified anti-perovskite material as well as a preparation method and application thereof. The anti-perovskite material has the quantum luminous efficiency of 99.8%, has a wide application prospect in the photoelectric field, is high in conductivity, and has a wide application prospect in a solid electrolyte of a solid-state lithium battery.

Description

Technical Field

[0001] The present invention relates to the technical fields of solid electrolyte materials and optoelectronic materials for solid-state lithium batteries, and particularly relates to an anti-perovskite material modified by doping thiocyanate, a preparation method thereof, and an application thereof. Background Art

[0002] The general structural formula of the anti-perovskite material can be written as X′3A'B', which is opposite to that of perovskite. Among them, the X′ position is usually a monovalent cation; the A' position is usually a monovalent anion; and the B' position is usually a divalent anion. The positions of cations and anions in the anti-perovskite and perovskite structures are opposite in the crystal structure. Benefiting from the same structure as perovskite, anti-perovskite materials have a wide range of applications in many fields such as magnetism, optoelectronic detection (Nature Photonics 2024, 18, 990–997), ferroelectricity (Angew. Chem. Int. Ed. 2018, 57, 11939-11942), superconductivity, catalysis, and solid-state batteries;

[0003] In the field of solid-state batteries, due to the high working voltage, non-reaction with the negative electrode, high ionic conductivity at room temperature, and low synthesis cost of anti-perovskite materials, they have attracted much attention from researchers in the field of solid-state batteries and can be used as solid electrolyte materials for lithium batteries.

[0004] In the field of optoelectronic materials, anti-perovskite materials also have important applications. For example, recent studies have shown that anti-perovskite materials Cs3MX5 (X = Cl - , Br - and I - ) have excellent luminescence properties and the first anti-perovskite light-emitting diode has been successfully prepared, with a maximum external quantum efficiency of up to 12.5% and a maximum brightness of up to 3990 cd / m -2 (ACS Energy Lett. 2021, 6, 1901-1911).

[0005] Therefore, anti-perovskite materials have a wide range of applications in both solid electrolyte materials for solid-state lithium batteries and optoelectronic materials. Therefore, further exploration of new anti-perovskite materials has important commercial value. Summary of the Invention

[0006] The technical problem to be solved by the present invention is that the application of anti-perovskite materials in solid-state batteries and optoelectronic materials is not comprehensive enough. For this reason, the present invention provides an anti-perovskite material modified by doping thiocyanate, Its preparation method and its applications. This inverse perovskite material has a quantum luminescence efficiency of 99.8%, and in optoelectronics which has a wide application prospect in the field, and has high conductivity and a wide application prospect in the solid electrolyte of solid-state lithium batteries.

[0007] The present invention solves the above technical problems through the following technical solutions.

[0008] The present invention provides an anti-perovskite material with the following general molecular formula A3B(SCN) n X 5-n ; where 0 < n < 5; A is a monovalent cation; B is a divalent cation; and X is a monovalent anion.

[0009] In the present invention, A is cesium ion, rubidium ion, potassium ion, sodium ion, lithium ion, methylamine cation or formamidine cation.

[0010] In the present invention, A is cesium ion.

[0011] In the present invention, B is manganese ion (Mn 2+ ), zinc ion (Zn 2+ ), lead ion (Pb 2+ ), platinum ion (Pt 2+ ), nickel ion (Ni 2+ ), palladium ion (Pd 2+ ) or tin ion (Sn 2+ ).

[0012] In the present invention, B is manganese ion (Mn 2+ ).

[0013] In the present invention, X is F - , Cl - , Br - or I - .

[0014] In the present invention, X is Br - .

[0015] In the present invention, the general molecular formula of the anti-perovskite material is Cs3Mn(SCN) n X 5-n .

[0016] In the present invention, the molecular formula of the perovskite material is Cs3Mn(SCN) n Br 5-n .

[0017] In the present invention, n is 0.1 - 1; for example, 0.1, 0.3, 0.5, 0.7, 0.9 or 1.

[0018] The present invention also provides a method for preparing an anti-perovskite material, which is prepared by the following method:

[0019] (4) Weigh the materials AX, BX2 and XSCN according to the ratio of the general molecular formula A3B(SCN) n X 5-n ;

[0020] (5) Dissolve the above materials in a solvent, heat and stir to obtain a perovskite precursor solution;

[0021] (6) Heat and volatilize the above perovskite precursor solution at 30-60 °C to crystallize it, and then dry it to obtain the perovskite material;

[0022] Wherein, X, A and B are defined as above.

[0023] In the present invention, AX is CsBr.

[0024] In the present invention, BX2 is MnBr2.

[0025] In the present invention, XSCN is CsSCN.

[0026] In the present invention, in step (2), the solvent is water and / or an alcohol solvent.

[0027] In the present invention, in step (2), when the solvent is an alcohol solvent, the alcohol solvent is methanol and / or ethanol.

[0028] In the present invention, in step (2), the time of heating and stirring is 0.1-12 hours.

[0029] In the present invention, in step (2), the temperature of heating and stirring is 20-60 °C.

[0030] The present invention also provides an application of the above perovskite material in X-ray scintillator imaging.

[0031] The present invention also provides an application of the above perovskite material in the new energy field; preferably in the new energy vehicle field.

[0032] The present invention also provides an application of the above perovskite material in the solid electrolyte material of a solid-state lithium battery.

[0033] On the basis of conforming to common general knowledge in the art, the above preferred conditions can be combined arbitrarily to obtain various preferred examples of the present invention.

[0034] The reagents and raw materials used in the present invention are all commercially available.

[0035] The positive and progressive effects of the present invention are as follows: The present invention provides a perovskite material, which has a quantum luminescence efficiency of 99%, has a wide application prospect in the optoelectronic field, and has a high conductivity and a wide application prospect in the solid electrolyte of a solid-state lithium battery. Description of the Drawings

[0036] Figure 1Photographs of the inverse perovskite material 2 in the ground state (left) and the excited state (right, excitation wavelength: 365 nm).

[0037] Figure 2 Fourier transform infrared spectroscopy test results of the inverse perovskite material 2.

[0038] Figure 3 Excitation spectrum of the inverse perovskite material 2.

[0039] Figure 4 Fluorescence emission spectrum of the inverse perovskite material 2 under 365 nm excitation.

[0040] Figure 5 Excitation spectrum of the inverse perovskite material 7.

[0041] Figure 6 Fluorescence emission spectrum of the inverse perovskite material 7 under 365 nm excitation. Detailed implementation mode

[0042] The present invention will be further illustrated by the following examples, but the present invention is not limited to the scope of the described examples. For the experimental methods without specific conditions in the following examples, they are carried out according to conventional methods and conditions, or selected according to the product specifications.

[0043] Example 1

[0044] Dissolve CsBr:MnBr2:CsSCN = 2.9:1:0.1 in 5 mL of H2O, where MnBr2 is 0.05 mmol (10.74 mg), CsBr is 0.145 mmol (30.86 mg), and CsSCN is 0.005 mmol (0.95 mg). Stir and heat at 50 °C for 12 h to prepare an inverse perovskite precursor solution; then slowly heat and evaporate the inverse perovskite precursor solution at 55 °C to allow it to slowly crystallize and precipitate, and finally dry it to obtain the inverse perovskite material 1.

[0045] Example 2

[0046] Dissolve CsBr:MnBr2:CsSCN = 2.7:1:0.3 in 5 mL of H2O, where MnBr2 is 0.05 mmol (10.74 mg), CsBr is 0.135 mmol (28.73 mg), and CsSCN is 0.015 mmol (2.86 mg). Stir and heat at 50 °C for 12 h to prepare an inverse perovskite precursor solution; then slowly heat and evaporate the inverse perovskite precursor solution at 55 °C to allow it to slowly crystallize and precipitate, and finally dry it to obtain the inverse perovskite material 2; the sample photographs of the inverse perovskite material 2 in the ground state and the excited state (excitation wavelength: 365 nm) are as Figure 1 shown.

[0047] The anti-perovskite material 2 was tested by Fourier transform infrared spectroscopy, and the experimental results are as follows Figure 2 shown. It can be seen from Figure 2 that the anti-perovskite material 2 has a characteristic peak of SCN at 2060 cm -1 −1, indicating the successful doping of SCN. -

[0048] Example 3

[0049] Dissolve CsBr:MnBr2:CsSCN = 2.5:1:0.5 in 5 mL of H2O, where MnBr2 is 0.05 mmol (10.74 mg), CsBr is 0.125 mmol (26.60 mg), and CsSCN is 0.025 mmol (4.77 mg). Stir and heat at 50 °C for 12 h to prepare an anti-perovskite precursor solution; then slowly heat and evaporate the anti-perovskite precursor solution at 55 °C to allow it to slowly crystallize and precipitate, and finally dry it to obtain the anti-perovskite material 3.

[0050] Example 4

[0051] Dissolve CsBr:MnBr2:CsSCN = 2.3:1:0.7 in 5 mL of H2O, where MnBr2 is 0.05 mmol (10.74 mg), CsBr is 0.115 mmol (24.47 mg), and CsSCN is 0.035 mmol (6.68 mg). Stir and heat at 50 °C for 12 h to prepare an anti-perovskite precursor solution; then slowly heat and evaporate the anti-perovskite precursor solution at 55 °C to allow it to slowly crystallize and precipitate, and finally dry it to obtain the anti-perovskite material 4.

[0052] Example 5

[0053] Dissolve CsBr:MnBr2:CsSCN = 2.1:1:0.9 in 5 mL of H2O, where MnBr2 is 0.05 mmol (10.74 mg), CsBr is 0.105 mmol (22.35 mg), and CsSCN is 0.045 mmol (8.59 mg). Stir and heat at 50 °C for 12 h to prepare an anti-perovskite precursor solution; then slowly heat and evaporate the anti-perovskite precursor solution at 55 °C to allow it to slowly crystallize and precipitate, and finally dry it to obtain the anti-perovskite material 5.

[0054] Example 6

[0055] ​Dissolve CsBr:MnBr2:CsSCN = 2:1:1 in 5 mL of H2O in a molar ratio, where MnBr2 is 0.05 mmol (10.74 mg), CsBr is 0.1 mmol (21.28 mg), and CsSCN is 0.05 mmol (9.55 mg). Stir and heat at 50 °C for 12 h to prepare a perovskite precursor solution; then slowly heat and evaporate the perovskite precursor solution at 55 °C to allow it to slowly crystallize and precipitate, and finally dry to obtain the perovskite material 6.

[0056] Comparative Example 1

[0057] Dissolve CsBr:MnBr2 = 3:1 in 5 mL of H2O in a molar ratio, where MnBr2 is 0.05 mmol (10.74 mg) and CsBr is 0.15 mmol (31.92 mg). Stir and heat at 50 °C for 12 h to prepare a perovskite precursor solution; then slowly heat and evaporate the perovskite precursor solution at 55 °C to allow it to slowly crystallize and precipitate, and finally dry to obtain the perovskite material 7.

[0058] Effect Example 1

[0059] Photophysical testing

[0060] Test the excitation spectrum, emission spectrum, and quantum yield of the perovskite materials of Examples 1-6 of the present invention and Comparative Example 1 by using an Edinburgh Analytical Instrument (FLS980 fluorescence spectrometer). Among them, The quantum yield is determined using an Edinburgh FLS980 spectrophotometer in an integrating sphere with a diameter of 142 mm.

[0061] Test procedure: Turn on the xenon lamp light source and preheat for 30 minutes, and at the same time cool the fluorescence spectrometer detector to -20 °C. At room temperature, thoroughly grind the above solid product into a uniform powder to avoid the influence of particle agglomeration on the test uniformity. Fix the sample on a solid sample holder to ensure that the test surface is aligned with the test light source. Subsequently, use ultraviolet light with a wavelength of 365 nm to excite and test the fluorescence emission and quantum yield of the sample.

[0062] Among them, the excitation spectrum of the perovskite material 2 is as Figure 3 shown, and the fluorescence emission spectrum of the perovskite material 2 is as Figure 4 shown; the excitation spectrum of the perovskite material 7 is as Figure 5 shown, and the fluorescence emission spectrum of the perovskite material 7 is as Figure 6 shown. The specific experimental results are shown in Table 1.

[0063] Table 1

[0064] Sample Maximum emission wavelength Quantum yield Inverse perovskite material 1 518 nm (green light) / Inverse perovskite material 2 518 nm (green light) 99.8％ Inverse perovskite material 3 518 nm (green light) / Inverse perovskite material 4 518 nm (green light) / Inverse perovskite material 5 518 nm (green light) / Inverse perovskite material 6 518 nm (green light) / Inverse perovskite material 7 515 nm (green light) 29.6％

[0065] Results and Discussion: As can be seen from the above table, after adding CsSCN, although the maximum emission wavelength hardly shifts, the external quantum efficiency of the inverse perovskite material is significantly improved from 29.6% to 99.8%, which is unexpected to those skilled in the art. It can be seen that this is an inverse perovskite material with very excellent performance.

[0066] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A perovskite - like material, characterized in that, It has the following general molecular formula A3B(SCN) n X 5-n ; where: 0<n<5； A is cesium ion, rubidium ion, potassium ion, sodium ion, lithium ion, methylamine cation or formamidine cation; B is manganese ion, zinc ion, lead ion, platinum ion, nickel ion, palladium ion or tin ion; X is F - , Cl - , Br - or I.

2. The anti-perovskite material according to claim 1, characterized in that, It satisfies one or more of the following conditions: (1) B is manganese ion; (2) X is Br - ; (3) A is cesium ion.

3. The anti-perovskite material according to claim 1, characterized in that, The molecular general formula of the inverse perovskite material is Cs3Mn(SCN) n X 5-n .

4. The anti-perovskite material according to claim 1, wherein The molecular formula of the inverse perovskite material is Cs3Mn(SCN) n Br 5-n , where n is 0.1 - 1.

5. The anti-perovskite material according to claim 1, characterized in that, n is 0.1, 0.3, 0.5, 0.7, 0.9 or 1.

6. A preparation method of an inverse perovskite material, which is prepared by the following method: (1) Weigh the materials AX, BX2, and XSCN according to the molecular general formula A3B(SCN) n X 5-n in the specified proportion; (2) Dissolve the weighed materials in a solvent, heat and stir to obtain an inverse perovskite precursor solution; (3) Heat and volatilize the inverse perovskite precursor solution at 30 - 60 °C to crystallize it, and then dry it to obtain the inverse perovskite material; Among them, The X, A and B are defined as in claim 1.

7. The preparation method of the inverse perovskite material according to claim 6, characterized in that, It satisfies one or more of the following conditions: (1) AX is CsBr; (2) BX2 is MnBr2 (3) XSCN is CsSCN; (4) In step (2), the solvent is water and / or an alcohol solvent.

8. The preparation method of the inverse perovskite material according to claim 7, wherein In step (2), when the solvent is an alcohol solvent, the alcohol solvent is methanol and / or ethanol.

9. An application of the inverse perovskite material according to any one of claims 1 - 8 in X-ray scintillator imaging.

10. An application of the inverse perovskite material according to any one of claims 1 - 8 in a solid electrolyte of a solid-state lithium battery.

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