Nanobatteries

Nanobatteries are batteries that are fabricated employing technology at the nanoscale, a scale of minuscule particles that measure less than 100 nanometers or 100x10^-9 meters. In comparison, traditional Li-Ion technology uses active materials, such as cobalt-oxide, with particles that range in size between 5 and 20 micrometres. It is hoped that nano-engineering will improve many of the failings of present battery technology, such as re-charging time and battery 'memory'.

Several companies are researching and developing these technologies. In March of 2005, Toshiba announced that they had a new Lithium-Ion battery with a nanostructured lattice at the cathode and anode that allowed the battery to recharge a surprising eighty times faster than previously. Prototype models were able to charge to eighty percent capacity in one minute, and one hundred percent recharged after 10 minutes.

When a traditional lithium-ion battery is charged too quickly, it creates a bottleneck in which the lithium moving through electrolyte liquid from the negative electrode to the positive backs up on the surface of the liquid. Under slower charging, the lithium "hides" in void space and does not cause a problem.

"Liquid electrolyte is unstable in the presence of metallic lithium and will cause all sorts of problems. That is why it is imperative to observe the slow-charging rate rule with lithium-ion batteries," Donald Sadoway, MIT professor of materials chemistry and an electrochemistry researcher, explained to TechNewsWorld. Sadoway said the consequences could be as severe as the battery exploding.

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Nanotube batteries

Scientists at UCLA have made an interesting, yet useful invention. They built the first nanotube batteries, which will be, a great replace for modern Li-Ion or Li-Pol batteries. They are less than millimeter thin, and have the structure almost like the old rechargeable batteries do, using zinc-carbon makeup - they are composed of thin layers of zinc and manganese oxide over a layer of nanotubes. They are very thin and small, and because of nanotubes they are bendable too.

Unfortunately, the energy produced by this type of batteries is very small at this level. ^[1]

Toshiba

By using nano-material, Toshiba has increased the surface area of the lithium and widened the bottleneck, allowing the particles to pass through the liquid and recharge the battery more quickly. Toshiba states that it tested a new battery by discharging and fully recharging one thousand times at 77 degrees and found that it lost only one percent of its capacity, an indication of a long battery life.

Toshiba's battery is 3.8 mm thick, 62 mm high and 35 mm deep.

A123Systems

A123Systems has also developed a commercial nano Li-Ion battery. A123 Systems claims their battery has the widest temperature range at -30C to 70C. Unlike Toshiba's nanobattery, A123 Li-Ion batteries charge to "high capacity" in five minutes. Safety is a key feature touted by the A123 technology, with a video on their website of a nail drive test, in which a nail is driven through a traditional Li-Ion battery and an A123 Li-Ion battery, where the traditional battery flames up and bubbles at one end, the A123 battery simply emits a wisp of smoke at the penetration site. Thermal conductivity is another selling point for the A123 battery, with the claim that the A123 battery offers 4 times higher thermal conductivity than conventional Lithium-Ion cylindrical cells. The nanotechnology they employ is a patented nanophosphate technology.

Valence

Also in the market is Valence Technology, Inc. The technology they are marketing is Saphion Li-Ion Technology. Like A123, they are using a nanophosphate technology, and different active materials than traditional Li-Ion batteries.

Altair

AltairNano has also developed a nanobattery with a one-minute recharge. The advance that Altair claims to have made is in the optimization of nano-structured lithium titanate spinel oxide (LTO).

References

1. ^ Nano-batteries