The battery cells were tested in Altairnano’s labs at 6 minute charge and discharge rates. They were deep charged and discharged meaning they were taken to 100% charge and 0% charge respectively during the 6-minute cycles. Although tests involved full charges and discharges, partial charging and discharging of the battery does not appear to impact the life or the holding charge capacity of the batteries i.e. they exhibit no memory loss.
In theory, a 15,000 charge cycle life would translate into a battery that would last greater than 40 years if it was charged daily, as would be the case in an electric vehicle or plug-in hybrid electric vehicle environment. However, in practice, other wear and tear factors would realistically limit the actual life of the batteries to probably 20 years.
“These results represent a remarkable achievement by our battery development group. We believe that the commercial implications of such an extended life battery are significant and would seem to provide us with an as yet unmatched competitive advantage in the electric vehicle and plug-in hybrid electric vehicle markets, and potentially other markets,” said Altairnano President and CEO Alan J. Gotcher Ph.D.
The following excerpt from an Altairnano article on NanoSafe Battery Technology extols the power virtues of their batteries. It's well worth reading the 4 page pdf to get details of their technology.
NanoSafe batteries deliver power per unit weight and unit volume several times that of conventional lithium ion batteries. Altairnano laboratory measurements indicate power density as high as 4000 W/Kg and over 5000W/liter. By using nano-titanate materials as the negative electrode material, the formation of an SEI is eliminated. (When a lithium ion battery, with a carbon negative electrode, is first charged a protective layer (called the Solid Electrolyte Interface or SEI) is formed on the surface of the highly reactive negative electrode.) In addition, the nano-titanate particles are up to 100 times smaller than a typical graphite particle thereby greatly reducing the distance a lithium atom must travel to be released from the particle. These properties also mean that even at very cold temperatures, a nano-titanate battery will produce high power.
The same technology also dramatically increases battery charge and discharge rates; rapid charge is important for next generation electric vehicles so they could be charged in a few minutes rather than hours as with current lithium ion technology. The NanoSafe cell has also demonstrated that surges of power can be delivered without risking thermal runaway or performance damage to the battery.
The first Altairnano NanoSafe™ batteries, based on this technology, were delivered in September 2006.
ALTI 1-yr. chart