(p148)
"The hexagonal lattice of carbon found in graphite allows the atoms within CNTs to move and vibrate freely, effectively producing electrical charges and thermal energy throughout the tube.
In addition to their high electric conductivity, CNTs have a large surface area, enabling increased electrochemical accessibility, and mechanical, chemical and electrochemical stability. These unique properties create the potential for CNTs to be used as a supplemental material for energy conversion and storage devices."
"Hydrogen is an element with the highest energy per mass of any other fuel, and it has become a key enabling technology."
http://materialsviews.com/tiny-tubes-hydrogen-storage-inside-single-walled-nanotubes/
"Efficient and safe hydrogen storage is one of the most significant barriers to the widespread use of hydrogen as a fuel in transportation and other energy sectors. In the conventional storage of liquid hydrogen the pressurized metal tank accounts for more than 90% of the total weight of the fuel, which more than neutralizes hydrogen’s high energy storage per unit weight. This is where the nanotubes have a great advantage as they are one of the strongest materials known despite being only 1 atomic layer thick. According to theoretical calculations, carbon nanotubes in this configuration should be able to withstand 2 GPa of hydrogen pressure before they start to leak. Even storage at 1 GPa corresponds to a weight storage efficiency of approximately 9 %, close to the 2015 target from the US Department of Energy. If this can be realized, the next generation of hydrogen-powered vehicles may indeed have gas tanks made of carbon nanotubes."
"The nanotubes were used as tiny high-pressure gas tanks with the ends sealed using plugs made of ice. A pressure of 5.0 MPa could be stored with no significant leakage and later released by simply heating the tubes to above the ice’s melting temperature."
http://pubs.acs.org/subscribe/archive/ci/30/i10/html/10fischer.html#10fisch6
"A single wall nano tube (SWNT) can be envisioned as a narrow strip of nanoscale graphene “chicken wire”, with a carbon atom at each apex of a hexagonal array and 0.14 nm between neighboring carbons, rolled up in a seamless cylinder 1–10 nm in diameter and as long as several micrometers. Furthermore, the strip need not be cut along a high-symmetry direction, so chiral and achiral tubes are possible."
"The tube’s symmetry, and hence the electronic properties, is determined by the orientation of the rectangle with respect to the hexagonal lattice."
"SWNT ropes can store hydrogen, as shown in this diagram (T. Yildirim/ NIST) for an idealized lattice of identical tubes.
Three distinct hydrogen environments are found: (1) intercalated between the tubes, (2) an internal annulus strongly interacting with the inner tube wall, and (3) a liquidlike core with weak or no interaction between hydrogen and carbon."
CNTs have enormous area together and their surface is extremely active > they can absorb plenty of H-atoms!, which are tiny. H2-storage problem has been solved!
139EN Storing energy in carbon nanotubes - hydrogen
https://www.azonano.com/article.aspx?ArticleID=4298"The hexagonal lattice of carbon found in graphite allows the atoms within CNTs to move and vibrate freely, effectively producing electrical charges and thermal energy throughout the tube.
In addition to their high electric conductivity, CNTs have a large surface area, enabling increased electrochemical accessibility, and mechanical, chemical and electrochemical stability. These unique properties create the potential for CNTs to be used as a supplemental material for energy conversion and storage devices."
"Hydrogen is an element with the highest energy per mass of any other fuel, and it has become a key enabling technology."
http://materialsviews.com/tiny-tubes-hydrogen-storage-inside-single-walled-nanotubes/
"Efficient and safe hydrogen storage is one of the most significant barriers to the widespread use of hydrogen as a fuel in transportation and other energy sectors. In the conventional storage of liquid hydrogen the pressurized metal tank accounts for more than 90% of the total weight of the fuel, which more than neutralizes hydrogen’s high energy storage per unit weight. This is where the nanotubes have a great advantage as they are one of the strongest materials known despite being only 1 atomic layer thick. According to theoretical calculations, carbon nanotubes in this configuration should be able to withstand 2 GPa of hydrogen pressure before they start to leak. Even storage at 1 GPa corresponds to a weight storage efficiency of approximately 9 %, close to the 2015 target from the US Department of Energy. If this can be realized, the next generation of hydrogen-powered vehicles may indeed have gas tanks made of carbon nanotubes."
"The nanotubes were used as tiny high-pressure gas tanks with the ends sealed using plugs made of ice. A pressure of 5.0 MPa could be stored with no significant leakage and later released by simply heating the tubes to above the ice’s melting temperature."
http://pubs.acs.org/subscribe/archive/ci/30/i10/html/10fischer.html#10fisch6
"A single wall nano tube (SWNT) can be envisioned as a narrow strip of nanoscale graphene “chicken wire”, with a carbon atom at each apex of a hexagonal array and 0.14 nm between neighboring carbons, rolled up in a seamless cylinder 1–10 nm in diameter and as long as several micrometers. Furthermore, the strip need not be cut along a high-symmetry direction, so chiral and achiral tubes are possible."
"The tube’s symmetry, and hence the electronic properties, is determined by the orientation of the rectangle with respect to the hexagonal lattice."
"SWNT ropes can store hydrogen, as shown in this diagram (T. Yildirim/ NIST) for an idealized lattice of identical tubes.
Three distinct hydrogen environments are found: (1) intercalated between the tubes, (2) an internal annulus strongly interacting with the inner tube wall, and (3) a liquidlike core with weak or no interaction between hydrogen and carbon."
CNTs have enormous area together and their surface is extremely active > they can absorb plenty of H-atoms!, which are tiny. H2-storage problem has been solved!
