Method for improving hydrogen storage property of lithium borohydride

Abstract

The invention provides a method for improving a hydrogen storage property of lithium borohydride, and belongs to the technical field of hydrogen storage materials. The method comprises the following steps of: mixing the lithium borohydride and alkaline-earth metal alanate according to the molar ratio of 2:1-10:1 under the protection of vacuum or inert gases, and heating mixed powder of the lithium borohydride and the alkaline-earth metal alanate to a certain temperature to ensure that the alkaline-earth metal alanate is decomposed into alkaline-earth metal hydride, aluminum or aluminum alloy in advance. By the method, double effects of in situ and concerted catalysis in the process of discharging and absorbing hydrogen of the lithium borohydride by using the alkaline-earth metal alanate are achieved, so that a hydrogen discharging temperature of the lithium borohydride is greatly reduced, and the hydrogen absorbing and discharging dynamic properties of the lithium borohydride are improved. The method is suitable for storing the hydrogen safely and efficiently and is particularly applied in fields of hydrogen fuel cells and the like.

Description

technical field

[0001] The invention belongs to the technical field of hydrogen storage materials, and in particular relates to a method for improving the hydrogen storage performance of lithium borohydride. Background technique

[0002] Compared with other forms of energy, hydrogen energy has the advantages of cleanliness, high calorific value, wide sources, and multiple utilization methods. Its development and application is one of the best options to solve energy crisis and environmental pollution. In the entire hydrogen energy system, hydrogen storage is the key to the application of hydrogen energy, and it is also one of the main technical difficulties currently limiting the commercialization of hydrogen fuel cell vehicles. Compared with low-temperature liquid and high-pressure gaseous hydrogen storage technologies, the solid-state storage of hydrogen by using the interaction between hydrogen storage materials and hydrogen has the advantages of safety, efficiency and ec...

Examples

Embodiment 1

[0019] Example 1: In a glove box filled with argon, LiBH was weighed according to a molar ratio of 2:1 4 and MgAl 2 h 8 The two raw material powders were poured into a stainless steel ball mill tank with a volume of 250 ml, and mechanically mixed with a planetary ball mill for 2 h at a ball-to-material ratio of 20:1, a speed of 400 rpm, and a vacuum. At a heating rate of 3°C / min, for 2LiBH 4 / MgAl 2 h 8 The mixed powders were heat treated and their thermal hydrogen release properties were measured. like figure 1 Shown, MgAl 2 h 8 Complete its decomposition process in the temperature range of 120 ~ 290 ° C (X-ray diffraction analysis shows that the decomposition product is Mg 2 Al 3 and Al), in MgAl 2 h 8 Under the catalysis of the decomposition products, LiBH 4 Hydrogen release starts at 290°C and ends at 440°C, 2LiBH 4 / MgAl 2 h 8 The total hydrogen release of the mixed powder is as high as 10.5 wt.%. figure 2 2LiBH 4 / MgAl 2 h 8 The first hydrogen desorp...

Embodiment 2

[0020] Example 2: In a glove box filled with argon, LiBH was weighed according to a molar ratio of 6:1 4 and CaAl 2 h 8 The two raw material powders were poured into a stainless steel ball mill tank with a volume of 250 ml, and mechanically mixed with a planetary ball mill for 2 h at a ball-to-material ratio of 20:1, a speed of 400 rpm, and argon protection. At a heating rate of 3°C / min, for 6LiBH 4 / CaAl 2 h 8 The mixed powders were heat treated and their thermal hydrogen release properties were measured. like image 3 Shown, CaAl 2 h 8 Complete its decomposition process in the temperature range of 130 ~ 250 ° C (X-ray diffraction analysis shows that the decomposition product is CaH 2 and Al), in CaAl 2 h 8 Under the catalysis of the decomposition products, LiBH 4 Hydrogen release starts at 290°C and ends at 470°C, 6LiBH 4 / CaAl 2 h 8 The total hydrogen release of the mixed powder is as high as 11.2 wt.%. Figure 4 6LiBH 4 / CaAl 2 h 8 Kinetic curves of hydro...

Embodiment 3

[0021] Example 3: In a glove box filled with argon, LiBH was weighed according to a molar ratio of 4:1 4 and Sr 2 H 7 The two raw material powders were poured into a stainless steel ball mill tank with a volume of 100 ml, and mechanically mixed with a planetary ball mill for 4 h at a ball-to-material ratio of 15:1, a speed of 400 rpm, and a vacuum. At a heating rate of 3°C / min, for 4LiBH 4 / Sr 2 H 7 The mixed powders were heat treated and their thermal hydrogen release properties were measured. Such as Figure 5 Shown, Sr 2 H 7 Complete its decomposition process in the temperature range of 160 ~ 270 ° C (X-ray diffraction analysis shows that the decomposition product is SrAl 4 and SrH 2 ), at Sr 2 H 7 Under the catalysis of the decomposition products, LiBH 4 The dehydrogenation starts at 300°C, and the dehydrogenation process can be basically completed at 460°C, and the hydrogen desorption amount is greater than 5.0 wt.%. At the same time, 4LiBH 4 / Sr 2 H 7 The...

technical field

[0001] The invention belongs to the technical field of hydrogen storage materials, and in particular relates to a method for improving the hydrogen storage performance of lithium borohydride. Background technique

[0002] Compared with other forms of energy, hydrogen energy has the advantages of cleanliness, high calorific value, wide sources, and multiple utilization methods. Its development and application is one of the best options to solve energy crisis and environmental pollution. In the entire hydrogen energy system, hydrogen storage is the key to the application of hydrogen energy, and it is also one of the main technical difficulties currently limiting the commercialization of hydrogen fuel cell vehicles. Compared with low-temperature liquid and high-pressure gaseous hydrogen storage technologies, the solid-state storage of hydrogen by using the interaction between hydrogen storage materials and hydrogen has the advantages of safety, efficiency and ec...

Examples

Embodiment 1

[0019] Example 1: In a glove box filled with argon, LiBH was weighed according to a molar ratio of 2:1 4 and MgAl 2 h 8 The two raw material powders were poured into a stainless steel ball mill tank with a volume of 250 ml, and mechanically mixed with a planetary ball mill for 2 h at a ball-to-material ratio of 20:1, a speed of 400 rpm, and a vacuum. At a heating rate of 3°C / min, for 2LiBH 4 / MgAl 2 h 8 The mixed powders were heat treated and their thermal hydrogen release properties were measured. like figure 1 Shown, MgAl 2 h 8 Complete its decomposition process in the temperature range of 120 ~ 290 ° C (X-ray diffraction analysis shows that the decomposition product is Mg 2 Al 3 and Al), in MgAl 2 h 8 Under the catalysis of the decomposition products, LiBH 4 Hydrogen release starts at 290°C and ends at 440°C, 2LiBH 4 / MgAl 2 h 8 The total hydrogen release of the mixed powder is as high as 10.5 wt.%. figure 2 2LiBH 4 / MgAl 2 h 8 The first hydrogen desorp...

Embodiment 2

[0020] Example 2: In a glove box filled with argon, LiBH was weighed according to a molar ratio of 6:1 4 and CaAl 2 h 8 The two raw material powders were poured into a stainless steel ball mill tank with a volume of 250 ml, and mechanically mixed with a planetary ball mill for 2 h at a ball-to-material ratio of 20:1, a speed of 400 rpm, and argon protection. At a heating rate of 3°C / min, for 6LiBH 4 / CaAl 2 h 8 The mixed powders were heat treated and their thermal hydrogen release properties were measured. like image 3 Shown, CaAl 2 h 8 Complete its decomposition process in the temperature range of 130 ~ 250 ° C (X-ray diffraction analysis shows that the decomposition product is CaH 2 and Al), in CaAl 2 h 8 Under the catalysis of the decomposition products, LiBH 4 Hydrogen release starts at 290°C and ends at 470°C, 6LiBH 4 / CaAl 2 h 8 The total hydrogen release of the mixed powder is as high as 11.2 wt.%. Figure 4 6LiBH 4 / CaAl 2 h 8 Kinetic curves of hydro...

Embodiment 3

[0021] Example 3: In a glove box filled with argon, LiBH was weighed according to a molar ratio of 4:1 4 and Sr 2 H 7 The two raw material powders were poured into a stainless steel ball mill tank with a volume of 100 ml, and mechanically mixed with a planetary ball mill for 4 h at a ball-to-material ratio of 15:1, a speed of 400 rpm, and a vacuum. At a heating rate of 3°C / min, for 4LiBH 4 / Sr 2 H 7 The mixed powders were heat treated and their thermal hydrogen release properties were measured. Such as Figure 5 Shown, Sr 2 H 7 Complete its decomposition process in the temperature range of 160 ~ 270 ° C (X-ray diffraction analysis shows that the decomposition product is SrAl 4 and SrH 2 ), at Sr 2 H 7 Under the catalysis of the decomposition products, LiBH 4 The dehydrogenation starts at 300°C, and the dehydrogenation process can be basically completed at 460°C, and the hydrogen desorption amount is greater than 5.0 wt.%. At the same time, 4LiBH 4 / Sr 2 H 7 The...

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