Press Release Source: Altair Nanotechnologies Inc.
Altair Nanotechnologies Details Long Life Features of its Nano Titanate Battery
Thursday September 7, 9:45 am ET
Long Life Combined with Safety and Fast Charge Provides Compelling Battery Proposition
RENO, Nev.--(BUSINESS WIRE)--Sept. 7, 2006--Altair Nanotechnologies Inc. (NASDAQ: ALTI - News), a leading provider of advanced nanomaterials and alternative energy solutions detailed why its NanoSafe(TM) nano titanate battery technology provides fundamental improvements over other batteries technologies for the rechargeable battery market.
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In anticipation of Altairnano's delivery of its first NanoSafe battery pack in September, this is the third of four planned news releases identifying features of Altairnano NanoSafe batteries that may prove advantageous in the power rechargeable battery market. The next and final battery backgrounder will discuss battery power capacity. The previous two feature releases detailed the NanoSafe battery fast charge and safety attributes. The combination of these features has the potential to make Altairnano's NanoSafe batteries ideal for power applications such as electric vehicles and hybrid electric vehicles.
How Does a Rechargeable Battery Work?
A battery consists of a positive electrode, a negative electrode, a porous separator that keeps the electrodes from touching, and an ionic electrolyte, which is the conducting medium for ions (charged particles) between the positive and the negative electrodes. When the battery is being charged, ions transfer from the positive to the negative electrodes via the electrolyte. On discharge these ions return to the positive electrode releasing energy in the process.
Existing Lithium Ion Batteries
Rechargeable lithium ion batteries generally 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 and are then released on discharge. When the lithium ions enter or leave the graphite particles, the particles expand or shrink to accommodate the lithium ion's size which is larger than the original site within the graphite particle that the ion occupies. Over the life of the battery, this repeated expansion and shrinkage fatigues the graphite particles. As a consequence the particles break apart, causing a loss in electrical contact between the resulting particles thereby reducing battery performance. The same process is repeated over the dynamic life of the battery - particle fatigue breakage and diminished performance until the battery is no longer useful.
The Altairnano NanoSafe(TM) Battery
Altairnano solved this problem using an innovative approach to rechargeable battery chemistry by replacing graphite with a patented nano-titanate material as the negative electrode in its NanoSafe batteries.
This nano-titanate material is a "zero strain" material in terms of lithium ion internal deposition and release. The lithium ions have the same size as the sites they occupy in the nano-titanate particles. As a result the nano-titanate particles do not have to expand or shrink when the ions are entering or leaving the nano-titanate particles, therefore resulting in no (zero) strain to the nano-titanate material. This property results in a battery that can be charged and discharged significantly more often than conventional rechargeable batteries because of the absence of particle fatigue that plagues materials such as graphite. Conventional lithium batteries can be typically charged about 750 times before they are no longer useful, whereas, in laboratory testing, the Altairnano NanoSafe battery cells have now achieved over 9,000 charge and discharge cycles at charge and discharge rates up to 40 times greater than are typical of common batteries, and they still retain up to 85% charge capacity.
As an example of the application significance of this feature if a conventional lithium battery is charged and discharged every day then it would typically last for about 2 years. Under the same scenario, an Altairnano battery would be projected to last 25 years. This durability is critical in a high value application like electric vehicles.
Altairnano will be demonstrating its NanoSafe battery technology at the California Air Resources Board Zero Emission Vehicles meeting in Sacramento, September 25th through 27th, 2006.
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