Altair Nanotechnologies Inc. (NASDAQ: ALTI - News), provider of lithium-ion batteries, in a press release has detailed why its battery technology provides fundamental improvements in charge rates, measured in minutes versus hours required for other rechargeable batteries.
Rechargeable lithium ion batteries currently use graphite for the negative electrode and typically lithium cobalt oxide for the positive electrode. The electrolyte is a lithium salt dissolved in an organic solvent which is flammable.
During charge, lithium ions deposit inside the graphite particles. However the rate at which lithium ions can deposit is limited by the electro-chemical properties of the graphite, and if they can not enter the graphite particles they, instead, may collect (plate) on the negative electrode's surface as lithium metal. If this plating occurs, the battery will severely degrade in performance and in extreme cases, will short, causing overheating and thermal runaway - a major fire hazard.
Altairnano solved this problem by replacing graphite with a patented nano-titanate material as the negative electrode in its NanoSafe batteries. By using nano-titanate materials as the negative electrode material, lithium metal plating does not occur because the electro-chemical properties of the nano-titanate allow the deposition of lithium in the particles at high rates. No undesirable interaction takes place with the electrolyte in the Altairnano batteries, which permits the battery to be charged very rapidly, without the risk of shorting or thermal runaway.
Altairnano is delivering its first NanoSafe battery pack in September to Phoenix Motorcars for incorporation into an electric vehicle. Phoenix Motorcars, based in Ojai, California, is an early leader in the effort to mass produce full function, freeway ready electric automobiles.
Lien: The Energy Blog: Altair Nanotechnologies Details Fast Charge Features of Its Nano Titanate Battery.