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Old 03-28-2008, 08:00 AM   #4
brian eiland
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Join Date: Jul 2004
Location: Washington DC, Annapolis MD, Thailand
Posts: 622
Li-Ion Electrode Problems & Material

Quote:
Originally Posted by FISHTIGUA
...found on a Asia B2B website in Tiawan a company that made Li-Ion batteries in any size you wanted.
Be careful, not all Li-Ion batteries are the same.

...from Altairnano website
New anode material
The principal advance that Altairnano has made is in the optimization of nano-structured lithium titanate spinel oxide (LTO) electrode materials that replace the graphite electrode materials found in negative electrodes of current Li-Ion batteries. So far these have been combined with positive electrodes from common lithium ion batteries.


Faster recharging and discharging
An electrode made with nanomaterials does not react with the electrolytes used in most lithium ion systems. No reaction means that no Solid Electrolyte Interphase (SEI) barrier is formed around the electrode, making it easier for lithium ions to reach the surface of the electrode. And, with a nano-structured component, there’s more surface area available to the ions—up to 100 times more surface area than with conventional, graphite electrodes.

The nanomaterials facilitate access to the active sites required for battery operation. What’s more, the small size of the materials dramatically reduces the distance from the surface to the sites—all of which helps accelerate recharging and discharging.


Longer battery life
The mechanical stress and strain caused by ions entering and exiting electrodes reduces the life of a battery. We offer zero-strain materials that change little with ion movement, enhancing battery calendar and cycle life.


Operation in extreme temperature conditions
If a battery has a SEI barrier, it can’t be charged at temperatures below 32° Fahrenheit. The pores in the barrier close, eliminating access to the active sites. An electrode with our nanomaterials will not form a SEI barrier, allowing it to safely operate down to -30°C. Even at this low temperature nearly 90% of room temperature charge retention is realized from Altairnano’s nano lithium titanium oxide cells at 2C rates. Traditional Li-Ion technology possesses virtually no charging capabilities at this low temperature.

High operating temperature tests on Altairnano based cells have been conducted at 65°C where we have demonstrated 9C 90% charge retention.


Ultra-safe characteristics
Altairnano has performed “hot box” exercises on our batteries at temperatures up to 240°C — which is more than 100°C above the temperature at which graphite-based batteries can explode — with zero explosions or safety concerns. In addition, we’ve performed high-rate overcharge, puncture, crush, drop and other comparative tests alongside a wide range of graphite-based battery cells with, again, no malfunctions, explosions or safety concerns exhibited by the nano-structured Altairnano nLTO cells. In comparison, the graphite cells, put to the same tests, routinely smoked, caught fire and exploded.
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