A preparation method, product and application of magnesium titanate / tin dioxide / magnesium titanate battery material

Abstract

The invention provides a preparation method of magnesium titanate / tin dioxide / magnesium titanate battery material and its products and applications. Carbon microsphere seeds are dispersed in a titanium salt solution, ultrasonicated, filtered, washed and dried to obtain A; a composite of TiO2 and carbon microsphere seeds is calcined to obtain a composite, which is dispersed in a tin salt solution, and steps 1) and 2) are repeated to obtain a triple composite of tin dioxide, TiO2 and gradually reduced carbon microsphere seeds, which is dispersed in a titanium salt solution, and steps 1) and 2) are repeated until the carbon microsphere seeds are completely consumed to obtain a triple composite of TiO2, tin dioxide and TiO2; the composite and soluble magnesium salt are dissolved in deionized water, magnetically stirred to uniformity, vacuum dried, and calcined at 600-800°C for 3-5 h to obtain magnesium titanate / tin dioxide / magnesium titanate. The first discharge specific capacity is about 199 mAh / g under the condition of 500 mA / g, and the discharge specific capacity is about 175 mAh / g after 50 cycles.

Description

Technical Field

[0001] The present invention relates to a method for preparing a magnesium ion battery material, in particular to a method for preparing a magnesium titanate / tin dioxide / magnesium titanate battery material and its product and application, and a method for preparing a magnesium titanate@superoxide magnesium titanate magnesium ion battery material. Background Art

[0002] With the development of human society, the contradiction between the shortage of global energy resources and the increasing demand for energy has become increasingly acute. The development of a battery system with high energy density has become the main goal of the current power system. Although lithium-ion batteries with high specific energy and environmental friendliness have been widely used in portable mobile appliances such as mobile phones and laptops, as well as power sources for electric bicycles and electric vehicles. However, since the safety of lithium-ion batteries has not been properly resolved, there is still a lot of work to be done in the application of lithium-ion batteries as power batteries. Magnesium, one of the most abundant light metal elements on the earth, is widely used in many fields due to its good physical and chemical properties. Now there are many studies on secondary magnesium batteries, all based on secondary lithium-ion batteries. Since magnesium and lithium are in diagonal positions in the periodic table, in addition to their similar atomic radius and chemical properties, the melting point of magnesium (648.8 ℃) is much higher than that of lithium (180.5 ℃), and it is not as active as lithium metal, so secondary magnesium batteries are better in safety. Although the mass capacity is not as high as lithium (3862 mAh g -1 ) but still pretty impressive (2205 mAh g -1 ). In addition, my country has extremely rich magnesium resources, the price of magnesium is much lower than that of lithium, and magnesium is environmentally friendly, so secondary magnesium batteries are gaining more and more attention.

[0003] Magnesium titanate has a wide range of applications and can currently be used as a magnesium-ion battery material. This material is considered to be a promising magnesium-ion battery material.

[0004] The present invention provides a method for preparing magnesium titanate / tin dioxide / magnesium titanate battery materials. The material is synthesized using carbon microspheres as seeds to prepare a complex structure with multiple cores. The multi-core structure has a special active site closed structure, forming a unique closed microenvironment, protecting the core from external chemical corrosion, and thus improving the electrochemical performance of the composite material. Summary of the invention

[0005] The present invention aims to provide a method for preparing a magnesium titanate / tin dioxide / magnesium titanate battery material.

[0006] Another object of the present invention is to provide a magnesium titanate / tin dioxide / magnesium titanate battery material product prepared by the above method.

[0007] Another object of the present invention is to provide an application of the above product.

[0008] The object of the present invention is achieved by the following scheme: A method for preparing a magnesium titanate / tin dioxide / magnesium titanate battery material, characterized in that the specific steps of the method are:

[0009] 1) Dispersing carbon microsphere seeds into a titanium salt (2-4 M) solution so that the molar ratio of carbon microsphere seeds to titanium salt is 1:5, ultrasonically assisted at 30-50 °C for 6-8 h, then filtered, washed with deionized water 2-3 times, and dried to obtain A;

[0010] 2) calcining the above A at 500-600 °C for 2-3 h at a heating rate of 1-2 °C / min in air, and maintaining the temperature at 300-400 °C for 30-60 min to obtain a composite of TiO2 and carbon microsphere seeds, marked as B;

[0011] 3) Disperse B into a solution containing tin salt (2~4 M) so that the molar ratio of tin salt to TiO2 is 3:1, and repeat steps 1) and 2) to obtain a triple complex of tin dioxide, TiO2, and gradually shrinking carbon microsphere seeds, marked as C;

[0012] 4) Disperse C in a titanium salt (2-4 M) solution so that the molar ratio of titanium salt to SnO2 is 3:1, repeat steps 1) and 2), until the carbon microsphere seeds are completely consumed, and obtain a triple complex of TiO2, tin dioxide, and TiO2;

[0013] 5) Dissolve TiO2, tin dioxide, a triple complex of TiO2 and a soluble magnesium salt in deionized water, stir magnetically for 1 to 2 h until the mixture is uniformly mixed, dry in a vacuum oven overnight, and calcine in a muffle furnace at 600 to 800 °C for 3 to 5 h to obtain magnesium titanate / tin dioxide / magnesium titanate.

[0014] Preferably, in step 1), the titanium salt is one of tetrabutyl titanate, isopropyl titanate or ethyl titanate or a combination thereof.

[0015] Preferably, in step 3), the tin salt is one of tin citrate, tin acetate or tin chloride or a combination thereof.

[0016] Preferably, in step 5), the magnesium salt is one or a combination of magnesium citrate, magnesium acetate or magnesium chloride.

[0017] The present invention provides a magnesium titanate / tin dioxide / magnesium titanate battery material, which is prepared according to any of the above methods.

[0018] The present invention provides an application of a magnesium titanate / tin dioxide / magnesium titanate battery material in the field of battery materials.

[0019] Beneficial effects:

[0020] The present invention provides a method for preparing magnesium titanate / tin dioxide / magnesium titanate battery materials, wherein the material is synthesized using carbon microspheres as seeds to prepare a complex structure with multiple cores, and the multi-core structure has a special active site closed structure, forming a unique closed microenvironment, protecting the core from external chemical corrosion, thereby improving the electrochemical performance of the composite material. The first discharge specific capacity is about 199 mAh / g under the condition of 500 mA / g, and after 50 cycles, the discharge specific capacity is about 175 mAh / g. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a cycle life diagram of the magnesium titanate / tin dioxide / magnesium titanate battery material of Example 1.

[0022] The first discharge capacity at 500 mA / g is about 199 mAh / g. After 50 cycles, the discharge capacity is about 175 mAh / g. DETAILED DESCRIPTION

[0023] The present invention is described in detail through the following specific examples, but the protection scope of the present invention is not limited to these embodiments.

[0024] Embodiment 1:

[0025] A magnesium titanate / tin dioxide / magnesium titanate battery material is prepared according to the following steps:

[0026] 1) Dispersing carbon microsphere seeds into 2M tetrabutyl titanate solution, so that the molar ratio of carbon microsphere seeds to tetrabutyl titanate is 1:5, after ultrasonic assistance at 40°C for 6h, filtering, washing with deionized water twice, and drying to obtain A;

[0027] 2) calcining the above A at 600 °C for 2 h at a heating rate of 2 °C / min in air, and keeping the temperature at 400 °C for 30 min to obtain a composite of TiO2 and carbon microsphere seeds, marked as B;

[0028] 3) Disperse B into a 2M tin chloride solution so that the molar ratio of tin chloride to TiO2 is 3:1, and repeat steps 1) and 2) to obtain a triple complex of tin dioxide, TiO2, and gradually shrinking carbon microsphere seeds, marked as C;

[0029] 4) Disperse C in a 2M tetrabutyl titanate solution, so that the molar ratio of tetrabutyl titanate to SnO2 is 3:1, repeat steps 1) and 2), until the carbon microsphere seeds are completely consumed, and obtain a triple complex of TiO2, tin dioxide, and TiO2;

[0030] 5) Dissolve TiO2, tin dioxide, a triple complex of TiO2 and soluble magnesium citrate in deionized water, stir magnetically for 2 h until the mixture is uniformly mixed, dry in a vacuum oven overnight, and calcine in a muffle furnace at 600°C for 5 h to obtain magnesium titanate / tin dioxide / magnesium titanate.

[0031] Figure 1 This is a cycle life diagram of magnesium titanate / tin dioxide / magnesium titanate battery material in Example 1. The first discharge specific capacity of magnesium titanate / tin dioxide / magnesium titanate at 500 mA / g is about 199 mAh / g. After 50 cycles, the discharge specific capacity of magnesium titanate / tin dioxide / magnesium titanate is about 175 mAh / g.

[0032] Embodiment 2:

[0033] A magnesium titanate / tin dioxide / magnesium titanate battery material is prepared according to the following steps:

[0034] 1) Dispersing carbon microsphere seeds into 2M isopropyl titanate solution, so that the molar ratio of carbon microsphere seeds to titanium salt is 1:5, at 40°C for 6 hours with ultrasonic assistance, filtering, washing with deionized water twice, and drying to obtain A;

[0035] 2) calcining the above A at 600 °C for 2 h at a heating rate of 2 °C / min in air, and keeping the temperature at 300 °C for 60 min to obtain a composite of TiO2 and carbon microsphere seeds, marked as B;

[0036] 3) Disperse B into 2 M tin acetate solution, so that the molar ratio of tin acetate to TiO2 is 3:1, repeat steps 1) and 2) to obtain a triple complex of tin dioxide, TiO2, and gradually shrinking carbon microsphere seeds, marked as C;

[0037] 4) Disperse C in a 2M isopropyl titanate solution, so that the molar ratio of isopropyl titanate to SnO2 is 3:1, repeat steps 1) and 2), until the carbon microsphere seeds are completely consumed, and obtain a triple complex of TiO2, tin dioxide, and TiO2;

[0038] 5) Dissolve TiO2, tin dioxide, a triple complex of TiO2 and soluble magnesium acetate in deionized water, stir magnetically for 2 h until the mixture is uniformly mixed, dry in a vacuum oven overnight, and calcine in a muffle furnace at 70°C for 4 hours to obtain magnesium titanate / tin dioxide / magnesium titanate.

[0039] Embodiment three:

[0040] A magnesium titanate / tin dioxide / magnesium titanate battery material is prepared according to the following steps:

[0041] 1) Disperse the carbon microsphere seeds into a 4 M ethyl titanate solution so that the molar ratio of the carbon microsphere seeds to ethyl titanate is 1:5, and perform ultrasonication at 4°C for 6 h, filter, wash with deionized water 4 times, and dry to obtain A;

[0042] 2) calcining the above A at 600 °C for 2 h at a heating rate of 1 °C / min in air, and keeping the temperature at 400 °C for 30 min to obtain a composite of TiO2 and carbon microsphere seeds, marked as B;

[0043] 3) Disperse B into 4 M tin acetate solution, so that the molar ratio of tin acetate to TiO2 is 3:1, repeat steps 1) and 2) to obtain a triple complex of tin dioxide, TiO2, and gradually shrinking carbon microsphere seeds, marked as C;

[0044] 4) Disperse C in a 4 M ethyl titanate solution, so that the molar ratio of ethyl titanate to SnO2 is 3:1, repeat steps 1) and 2), until the carbon microsphere seeds are completely consumed, and obtain a triple complex of TiO2, tin dioxide, and TiO2;

[0045] 5) Dissolve TiO2, tin dioxide, a triple complex of TiO2 and soluble magnesium chloride in deionized water, stir magnetically for 2 h until the mixture is uniformly mixed, dry in a vacuum oven overnight, and calcine in a muffle furnace at 800°C for 3 h to obtain magnesium titanate / tin dioxide / magnesium titanate.

Claims

1. A method for preparing magnesium titanate / tin dioxide / magnesium titanate battery material, characterized in that: The steps include: 1) Disperse the carbon microsphere seeds in a 2-4 M titanium salt solution so that the molar ratio of the carbon microsphere seeds to the titanium salt is 1:5, and then perform ultrasonic-assisted heating at 30-50°C for 6-8 h, filter, wash with deionized water 2-3 times, and dry to obtain A; 2) calcining the above A at 500-600 °C for 2-3 h at a heating rate of 1-2 °C / min in air, and maintaining the temperature at 300-400 °C for 30-60 min to obtain a composite of TiO2 and carbon microsphere seeds, marked as B; 3) Disperse B into a 2-4 M tin salt solution, so that the molar ratio of tin salt to TiO2 is 3:1, and repeat steps 1) and 2) to obtain a triple complex of tin dioxide, TiO2, and gradually shrinking carbon microsphere seeds, marked as C; 4) Disperse C in a 2-4 M titanium salt solution, so that the molar ratio of titanium salt to SnO2 is 3:1, repeat steps 1) and 2), until the carbon microsphere seeds are completely consumed, and obtain a triple complex of TiO2, tin dioxide, and TiO2; 5) Dissolve TiO2, tin dioxide, a triple complex of TiO2 and a soluble magnesium salt in deionized water, stir magnetically for 1 to 2 h until the mixture is uniformly mixed, dry in a vacuum oven overnight, and calcine in a muffle furnace at 600 to 800 °C for 3 to 5 h to obtain magnesium titanate / tin dioxide / magnesium titanate.

2. The method for preparing a magnesium titanate / tin dioxide / magnesium titanate battery material according to claim 1, characterized in that: The titanium salt is one of tetrabutyl titanate, isopropyl titanate and ethyl titanate or a combination thereof.

3. The method for preparing a magnesium titanate / tin dioxide / magnesium titanate battery material according to claim 1, characterized in that: The tin salt is one of tin citrate, tin acetate or tin chloride or a combination thereof.

4. The method for preparing a magnesium titanate / tin dioxide / magnesium titanate battery material according to claim 1, characterized in that: The magnesium salt is one of magnesium citrate, magnesium acetate or magnesium chloride or a combination thereof.

5. The method for preparing a magnesium titanate / tin dioxide / magnesium titanate battery material according to any one of claims 1 to 4, characterized in that: Follow these steps: 1) Dispersing carbon microsphere seeds into 2M tetrabutyl titanate solution, so that the molar ratio of carbon microsphere seeds to tetrabutyl titanate is 1:5, after ultrasonic assistance at 40°C for 6h, filtering, washing with deionized water twice, and drying to obtain A; 2) calcining the above A at 600 °C for 2 h at a heating rate of 2 °C / min in air, and keeping the temperature at 400 °C for 30 min to obtain a composite of TiO2 and carbon microsphere seeds, marked as B; 3) Disperse B into a 2M tin chloride solution so that the molar ratio of tin chloride to TiO2 is 3:1, and repeat steps 1) and 2) to obtain a triple complex of tin dioxide, TiO2, and gradually shrinking carbon microsphere seeds, marked as C; 4) Disperse C in a 2M tetrabutyl titanate solution, so that the molar ratio of tetrabutyl titanate to SnO2 is 3:1, repeat steps 1) and 2), until the carbon microsphere seeds are completely consumed, and obtain a triple complex of TiO2, tin dioxide, and TiO2; 5) Dissolve TiO2, tin dioxide, a triple complex of TiO2 and soluble magnesium citrate in deionized water, stir magnetically for 2 h until the mixture is uniformly mixed, dry in a vacuum oven overnight, and calcine in a muffle furnace at 600°C for 5 h to obtain magnesium titanate / tin dioxide / magnesium titanate.

6. A method for preparing a magnesium titanate / tin dioxide / magnesium titanate battery material according to any one of claims 1 to 4, characterized in that: Follow these steps: 1) Dispersing carbon microsphere seeds into 2M isopropyl titanate solution, so that the molar ratio of carbon microsphere seeds to titanium salt is 1:5, at 40°C for 6 hours with ultrasonic assistance, filtering, washing with deionized water twice, and drying to obtain A; 2) calcining the above A at 600 °C for 2 h at a heating rate of 2 °C / min in air, and keeping the temperature at 300 °C for 60 min to obtain a composite of TiO2 and carbon microsphere seeds, marked as B; 3) Disperse B into 2 M tin acetate solution, so that the molar ratio of tin acetate to TiO2 is 3:1, repeat steps 1) and 2) to obtain a triple complex of tin dioxide, TiO2, and gradually shrinking carbon microsphere seeds, marked as C; 4) Disperse C in a 2M isopropyl titanate solution, so that the molar ratio of isopropyl titanate to SnO2 is 3:1, repeat steps 1) and 2), until the carbon microsphere seeds are completely consumed, and obtain a triple complex of TiO2, tin dioxide, and TiO2; 5) Dissolve TiO2, tin dioxide, a triple complex of TiO2 and soluble magnesium acetate in deionized water, stir magnetically for 2 h until the mixture is uniformly mixed, dry in a vacuum oven overnight, and calcine in a muffle furnace at 70°C for 4 hours to obtain magnesium titanate / tin dioxide / magnesium titanate.

7. A method for preparing a magnesium titanate / tin dioxide / magnesium titanate battery material according to any one of claims 1 to 4, characterized in that: Follow these steps: 1) Disperse the carbon microsphere seeds into a 4 M ethyl titanate solution so that the molar ratio of the carbon microsphere seeds to ethyl titanate is 1:5, and perform ultrasonication at 4°C for 6 h, filter, wash with deionized water 4 times, and dry to obtain A; 2) calcining the above A at 600 °C for 2 h at a heating rate of 1 °C / min in air, and keeping the temperature at 400 °C for 30 min to obtain a composite of TiO2 and carbon microsphere seeds, marked as B; 3) Disperse B into 4 M tin acetate solution, so that the molar ratio of tin acetate to TiO2 is 3:1, repeat steps 1) and 2) to obtain a triple complex of tin dioxide, TiO2, and gradually shrinking carbon microsphere seeds, marked as C; 4) Disperse C in a 4 M ethyl titanate solution, so that the molar ratio of ethyl titanate to SnO2 is 3:1, repeat steps 1) and 2), until the carbon microsphere seeds are completely consumed, and obtain a triple complex of TiO2, tin dioxide, and TiO2; 5) Dissolve TiO2, tin dioxide, a triple complex of TiO2 and soluble magnesium chloride in deionized water, stir magnetically for 2 h until the mixture is uniformly mixed, dry in a vacuum oven overnight, and calcine in a muffle furnace at 800°C for 3 h to obtain magnesium titanate / tin dioxide / magnesium titanate.

8. A magnesium titanate / tin dioxide / magnesium titanate battery material, characterized in that Prepared according to any one of claims 1 to 7.

9. Use of the magnesium titanate / tin dioxide / magnesium titanate battery material according to claim 8 in the field of magnesium ion batteries.

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