Activated magnesium boride materials for hydrogen storage

Patent metadata

Field	Value
Publication number	US-2020270127-A1
Application number	US-201816648661-A
Country	US
Kind code	A1
Filing date	Sep 21, 2018
Priority date	Sep 21, 2017
Publication date	Aug 27, 2020
Grant date	—

Abstract

Some embodiments described herein provide for methods for synthesizing magnesium borohydride from hydrogenation of magnesium boride at moderate temperature and pressure in the presence of a modifier. The modifier may be in form of hydrides, liquid hydrogen carriers, ammonia borane, metallic species, croconate anion based materials, ethers, amines or imines, metal carbides, borides, graphene, arenes, magnesium, aluminum, calcium or ionic liquids. Some embodiments provide for charging magnesium boride in presence of a modifier at high pressure hydrogen while simultaneously heating the material. The modification in some instances may lead to an improved magnesium boride product with enhanced properties for application in other hydrogen storage systems.

First claim

1 . A method of making hydrogen storage materials through modifications of magnesium boride, the method comprising milling magnesium boride in the presence of sub-stoichiometric amounts of at least one of an ether, arene, graphene, metal hydride, and metal in an inert atmosphere.

2 . The method of claim 1 , wherein the ether is tetrahydrofuran.

3 . The method of claim 1 , wherein the arene is anthracene or phenanthrene.

4 . The method of claim 1 , wherein the metal hydride is magnesium hydride.

5 . The method of claim 1 , wherein the metal is magnesium.

6 . A method for reversible storage of hydrogen based on magnesium boride which has been modified by the method of claim 1 , which has a cycling hydrogen charging pressure ≤400 atm and hydrogen charging/discharging temperature ≤300° C.

7 . A method for reversible storage of hydrogen based on magnesium boride that has been modified by the method of claim 1 which stores and releases hydrogen with a maintained hydrogen cycling capacity of ≥4.0 wt. %.

8 . A method of powering a vehicle apparatus, the method comprising:
modifying magnesium boride through mechanically mixing the magnesium boride in the presence of sub-stoichiometric amounts of at least one of an ether, arene, graphene, metal hydride, and metal in an inert atmosphere such that the hydrogen storage material maintains a hydrogen cycling capacity of ≥4 wt %; controlling the release of hydrogen upon heating the modified magnesium boride in a hydrogen reservoir system; and powering a vehicle with the released hydrogen.

9 . The method of claim 8 , wherein the hydrogen cycling capacity is ≥7 wt %.

10 . The method of claim 8 , wherein the inert atmosphere comprises nitrogen or argon.

11 . The method of claim 8 , wherein the mechanical mixing is ball milling.

12 . The method of claim 8 , wherein the arene is anthracene or phenanthrene.

13 . A method of synthesizing magnesium borohydride from magnesium boride, the method comprising:
hydrogenating a quantity of a reaction mixture comprising magnesium boride and an modifier to form magnesium borohydride, wherein the hydrogenating step is performed at a temperature at or below about 300° C. and at a hydrogen pressure at or below about 700 bar.

14 . The method of claim 13 , wherein the magnesium boride and the modifier are mechanically mixed, sonicated or thermally treated prior to hydrogenation.

15 . The method of claim 14 , wherein the mechanical mixing is in an inert or none inert environment.

16 . The method of claim 13 , further comprising evaporating any excess liquid from reaction mixture, if necessary.

17 . The method of claim 13 , wherein the hydrogenation is performed at the temperature at or below about 200° C.

18 . The method of claim 13 , wherein the hydrogenation is performed at the hydrogen pressure at or below about 400 bar.

19 . The method of claim 13 , wherein the modifier comprises, at least one of, hydrides, liquid hydrogen carriers, ammonia borane, metal species, metal compounds, croconates, ethers, amines, imines, polycyclic aromatic hydrocarbons, THF, polymeric S x N y or B x N y type, metal carbides, borides of aluminum or calcium, ionic liquids, hydrogen donating compounds, 2D and 3D materials such as graphene, graphite and graphene oxide; Grignard type reagents, organometallic compounds, and combinations thereof.

20 . The method of claim 13 , wherein the modifier comprises less than about 60 weight percent of the reaction mixture.

Assignees

• Univ Hawaii

Inventors

• Severa Godwin
• Jensen Craig M
• Sugai Cody
• Kim Stephen Young-Min

Classifications

• Y02E60/32

  Hydrogen storage · CPC title

• C01B35/04 Primary

  Metal borides · CPC title

• C01B3/0026 Primary

  Metals or metal hydrides · CPC title

• C01B6/04

  Hydrides of alkali metals, alkaline earth metals, beryllium or magnesium; Addition complexes thereof · CPC title