- Category: Green Transportation
07 Jan 2013
- Published on Monday, 07 January 2013 09:11
- Hits (1322)
The first all-electric, battery-powered locomotive in the United States is looking at a boost in performance after researchers from Penn State devised a new way to decrease sulfation damage in its rechargeable batteries.
The researchers were able to increase battery cell capacity by 41 percent and overall battery capacity by 30 percent.
The Norfolk Southern 999 of the Norfolk Southern Corporation is a prototype 1,500 horsepower electric locomotive that entirely runs on rechargeable batteries. It uses a lead-acid energy storage system comprised of 1,080 rechargeable 12-volt batteries for zero exhaust emission transportation (see related story).
Damage incurred during charging and recharging affects battery life. A leading cause of damage in these lead-acid batteries is sulfation, an accumulation of lead sulfate in the battery.
Penn State mechanical engineering professor Christopher Rahn and his team set out to study and answer the problem of sulfation in the locomotives batteries."We wanted to reverse the sulfation to rejuvenate the battery and bring it back to life," said Mr. Rahn.
For three months, Mr. Rahn and mechanical engineering research assistants Ying Shi and Christopher Ferone, cycled a lead-acid battery. Using electroimpedance spectroscopy, they were able to identify sulfation in one of six battery cells. They then designed a charging algorithm that could charge the battery and reduce sulfation. This successfully revived the dead cell and increased overall capacity.
They are now developing alternative models to allow charging right up to, but not past, the point in which sulfation begins, with an attempt to develop a way to prevent it from occurring in the first place.
Norfolk Southern originally partnered with the Department of Energy to develop the NS 999 in 2008. This most recent study was also funded by the D.O.E. – EcoSeed Staff