Using nanotechnology in the manufacture of batteries offers the following benefits:
Reducing the possibility of batteries catching fire by providing less flammable electrode material.
Increasing the available power from a battery and decreasing the time required to recharge a battery. These benefits are achieved by coating the surface of an electrode with nanoparticles. This increases the surface area of the electrode thereby allowing more current to flow between the electrode and the chemicals inside the battery. This technique could increase the efficiency of hybrid vehicles by significantly reducing the weight of the batteries needed to provide adequate power.
Increasing the shelf life of a battery by using nanomaterials to separate liquids in the battery from the solid electrodes when there is no draw on the battery. This separation prevents the low level discharge that occurs in a conventional battery, which increases the shelf life of the battery dramatically.
Researchers at North Carolina State University have demonstrated the use of silicon coated carbon nanotubes for in anodes for Li-ion batteries. They are predicting that the use of silicon can increase the capacity of Li-ion batteries by up to 10 times. However silicon expands during a batteries discharge cycle, which can damage silicon based anodes. By depositing silicon on nanotubes aligned parallel to each other the researchers hope to prevent damage to the anode when the silicon expands.
Researchers at Los Alamos National Laboratory have demonstrated a catalyst made from nitrogen-doped carbon-nanotubes, instead of platinum. The researchers believe this type of catalyst could be used in Lithium-air batteries, which can store up to 10 times as much energy as lithium-ion batteries.
Researchers at USC are developing a lithium ion battery that can recharge within 10 minutes using silicon nanoparticles in the anode of the battery. The use of silicon nanoparticles, rather than solid silicon, prevents the cracking of the electrode which occurs in solid silicon electrodes.
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 grew graphene on a metal substrate then grew 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 large molecule with a huge surface area.
Researchers at Stanford University have grown silicon nanowires on a stainless steel substrate and demonstrated that batteries using these anodes could have up to 10 times the power density of conventional lithium ion batteries. Using silicon nanowires, instead of bulk silicon fixes a problem of the silicon cracking, that has been seen on electrodes using bulk silicon. The cracking is caused because the silicon swells it absorbs lithium ions while being recharged, and contracts as the battery is discharged and the lithium ions leave the silicon. However the researchers found that while the silicon nanowires swell as lithium ions are absorbed during discharge of the battery and contract as the lithium ions leave during recharge of the battery the nanowires do not crack, unlike anodes that used bulk silicon.
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 at MIT have used carbon nanofibers to make lithium ion battery electrodes that show four times the storage capacity of current lithium ion batteries.
Researchers at Rensselaer have used graphene on the surface of anodes to make lithium-ion batteries that recharge about 10 times faster than conventional Li-ion batteries. Defects in the graphene sheet (introduced using a heat treatment) provide pathways for the lithium ions to attach to the anode substate.
The next step beyond lithium-ion batteries may be lithium sulfur batteries (the cathode contains the sulfur), which have the capability of storing several times the energy of lithium-ion batteries. Researchers at Stanford University are using cathodes made up of carbon nanofibers encapsulating the sulfur, while researchers at LMU Munic and Waterloo University are using cathodes made up of mesoporous carbon nanoparticles, with the sulfur inside the nanopores.
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.
Cathodes made of a nanocomposite designed to increase the energy density of Li-ion batteries.
Battery small enough to be implanted in the eye and power artificial retina
Long shelf life battery uses "nanograss" to separate liquid electrolytes from the solid electrode until power is needed.
Lithium ion batteries with nanoparticle (Nanophosphate™) electrodes that meet the safety requirements for electric cars while improving the performance.
Lithium ion batteries with electrodes made from nano-structured lithium titanate that significantly improves the charge/discharge capability at sub freezing temperatures as well as increasing the upper temperature limit at which the battery remains safe from thermal runaway.
Ultracapacitors using nanotubes may do even better than batteries in hybrid cars.Ultracapacitor using single atom thick graphene sheets to store electrical charge.
|A123Systems||Lithium-ion battery with the cathode made from nano-phosphate, literature is unclear as to whether this is nanoparticles of phosphate on a substrate or a nano-porous phosphate structure||Higher power, quicker recharge, less combustible than standard lithium-ion batteries|
|Mphase Technologies||Battery with chemicals isolated from electrode by "nanograss" when the battery is not in use||Very long shelf life|
|Altairenano||Lithium-ion battery with the anode composed of lithium titanate spindel nanoparticles||Higher power, quicker recharge, less combustible than standard lithium-ion batteries|
|Zpower||Silver-zinc battery using nanoparticles in the silver cathode||Higher power density, low combustibility|
More companies applying nanotechnology to batteries
Transportation Technology R&D Center at Argonne National Laboratory
United States Advanced Battery Consortium
Compiled by Earl Boysen of Hawk's Perch Technical Writing, LLC and UnderstandingNano.com. You can find him on Google+.
Visit our other Web site
Labs applying Nanotechnology to Batteries: