The use of carbon nanotubes in energy applications is being researched to improve the efficiency or reduce the cost of batteries, solar cells, and fuel cells. This page provides examples of how carbon nanoutbes are being used in energy applications.
Researchers at Rice University have developed electrodes made from carbon nanotubes grown on graphene with very high surface area and very low electrical resistance. The researchers first grow graphene on a metal substrate then grow carbon nanotubes on the graphene sheet. Because the base of each nanotube is bonded, atom to atom, to the graphene sheet the nanotube-graphene structure is essentially one molecule with a huge surface area.
Researchers at MIT have developed a technique to deposit aligned carbon nanotubes on a substrate for use as the anode, and possibly the cathode, in a lithium ion battery. The carbon nanotubes have organic molecules attached that help the nanotubes align on the substrate, as well as provide many oxygen atoms that provide points for lithium ions to attach to. This could increase the power density of lithium ion batteries significantly, perhaps by as much as 10 times. A battery manufacturer called Contour Systems has licensed this technology and are planning to use it in their next generation Li-ion batteries.
Researchers have built a solar cell that uses graphene as a electrode while using buckyballs and carbon nanotubes to absorb light and generate electrons. This process produces a solar cell composed only of carbon. The intent is to eliminate the need for higher cost materials and the complicated manufacturing techniques required to build conventional solar cells.
Researchers at Institute of Physical Chemistry of the Polish Academy of Sciences are developing a cathode using carbon nanotubes for use in fuel cells or batteries used to power medical implants.
Researchers at Rice University are using carbon nanotubes mixed with carbon black particles in one layer of a five layer battery that can be painted on a wide range of types of surfaces.
Carbon nanotubes can perform as a catalyst in a fuel cell, avoiding the use of expensive platinum on which most catalysts are based. Researchers have found that incorporating nitrogen and iron atoms into the carbon lattice of nanotubes results in nanotubes with catalytic properties.
Combining carbon nanotubes and buckyballs to produce solar cells. Some researchers combine the nanotubes and buckyballs with a polymer, while another group of researchers are only using nanotubes and buckyballs.
Producing ultracapacitors using nanotubes that may store much more energy than batteries in hybrid cars.