Graphene Oxide/Metal Nanocrystal Multilaminates the Atomic Limit for Safe, Selective Hydrogen Storage

Patent metadata

Field	Value
Publication number	US-2018186630-A1
Application number	US-201815893263-A
Country	US
Kind code	A1
Filing date	Feb 9, 2018
Priority date	Aug 10, 2015
Publication date	Jul 5, 2018
Grant date	—

Abstract

Various embodiments of the invention describe an environmentally stable, and exceptionally dense hydrogen storage (6.5 wt % and 0.105 kg H 2 /L in the total composite, 7.56 wt % in Mg) using atomically thin and gas-selective reduced graphene oxide sheets as encapsulants. Other approaches to protecting reactive materials involve energy intensive introduction of considerable amounts of inactive, protective matrix which compromises energy density. However, these multilaminates are able to deliver exceptionally dense hydrogen storage far-exceeding 2020 DOE target metrics for gravimetric capacity (5.5 wt %), and ultimate full-fleet volumetric targets (0.070 kg H 2 /L) for fuel cell electric vehicles. Methods of stabilizing reactive nanocrystalline metals in zero-valency also has wide-ranging applications for batteries, catalysis, encapsulants, and energetic materials.

First claim

1 . A composition of matter comprising:
reduced graphene oxide (rGO)—magnesium (Mg) nanocrystal nanolaminates.

2 . The composition of matter claim 1 , wherein a nanolaminate comprises two rGO sheets with Mg nanocrystals distributed there between.

3 . The composition of matter claim 2 , wherein the Mg nanocrystals are distributed in an approximately hexagonal pattern corresponding to a d-spacing of 2.778 Å.

4 . The composition of matter claim 3 , wherein the Mg nanocrystals are distributed in an approximately hexagonal close-packed (hcp) pattern.

5 . The composition of matter claim 4 , wherein the Mg nanocrystal size distribution is approximately 3.26 nanometers in diameter (±0.87 nanometers).

6 . The composition of matter claim 4 , wherein at least 50% of the Mg nanocrystals are zero-valent crystalline Mg.

7 . The composition of matter claim 2 , wherein the nanolaminate further comprises hydrogen (H 2 ).

8 . The composition of matter claim 2 , wherein the nanolaminate further comprises hydrogen (H 2 ) in the form of MgH 2 .

9 . The composition of matter claim 2 , wherein the nanolaminate further comprises approximately 6.5 weight percent hydrogen (H 2 ) and 0.105 kg H 2 /L and 7.56 weight percent of Mg nanocrystals.

10 . A method of preparing reduced graphene oxide (rGO)—magnesium (Mg) nanocrystal nanolaminates comprising:
ball-milling graphene oxide (GO) to break down the GO to GO platelets in order to complex with bis(cyclopentadienyl) magnesium (Cp 2 Mg);
preparing a lithium naphthalenide solution by dissolving naphthalene in tetrahydrofuran (THF), followed by the addition of Li metal to produce the lithium naphthalenide solution;
dispersing GO in the THF to form a GO solution;
adding a Cp 2 Mg solution to the GO solution to produce a GO/Cp 2 Mg solution;
adding the GO/Cp 2 Mg solution to the lithium naphthalenide solution to produce the reduced graphene oxide (rGO)—magnesium (Mg) nanocrystal nanolaminates;
centrifuging and washing the reduced graphene oxide (rGO)—magnesium (Mg) nanocrystal nanolaminates with THF; and
drying the graphene oxide (rGO)—magnesium (Mg) nanocrystal nanolaminates.

11 . (canceled)

Assignees

• Univ California

Inventors

• Urban Jeffrey J
• Cho Eun Seon
• Ruminski Anne M
• Aloni Shaul

Classifications

• B01J20/3085

  Chemical treatments not covered by groups B01J20/3007 - B01J20/3078 · CPC title

• B01J20/3021

  Milling, crushing or grinding · CPC title

• B01J20/04 Primary

  comprising compounds of alkali metals, alkaline earth metals or magnesium · CPC title

• B01J20/20

  comprising free carbon; comprising carbon obtained by carbonising processes · CPC title

• C01B3/0026

  Metals or metal hydrides · CPC title