‘Supercapacitive’ Batteries Can Be Made on Lead Acid Lines
New Castle, Pa.-based Axion Power says it’s completed shipping a $475,000 order for its PbC brand lead carbon batteries to the Norfolk Suffolk railroad for trials in a pure battery electric yard switcher locomotive, the line’s first, designated NS-999.
Axion says that it’s working with NS on an energy system for “over the road” hybrid locomotives too, and that its PbC technology can also be applied to trucks.
PbC batteries, the company says, outperform lead acid batteries yet can be manufactured on existing lead acid production lines, which abound worldwide. And Axion says that its lead carbon batteries outperform lithium ion batteries in terms recharge rates, significantly longer cycle lives in deep discharge applications, maintenance requirements – and cost.
The PbC battery may be more technically described as a “multi-celled asymmetrically supercapacitive lead-acid-carbon hybrid battery,” the company says, adding, “Where the negative electrodes in lead-acid batteries are simple sponge lead plates, our negative electrodes are five-layer assemblies that consist of a carbon electrode, a corrosion barrier, a current collector, a second corrosion barrier and a second carbon electrode.
Looking to the Truck Market Too
“These electrode assemblies are then sandwiched together with conventional separators and positive electrodes to make our battery, which is filled with an acid electrolyte, sealed and connected in series to the other cells,” Axion says.
Axion says that the batteries have been in lab testing since April 2004. “Our test protocol requires a complete charge-discharge cycle every 7 hours to a 100% depth of discharge,” the company says. “During testing, our laboratory prototypes have withstood more than 2,500 cycles before failure. In comparison, most lead-acid batteries designed for deep discharge applications can only survive 400 to 600 cycles under these operating conditions.”
Citing figures from the Argonne National Laboratory, Axion says that conversion of just one yard locomotive to all-battery power could save 85,000 gallons of diesel fuel per year. Conversion of a single over-the-road locomotive could save twice that.
‘The Chemistry of Choice’
“The PbC properties that make our battery the chemistry of choice for ‘all electric’ and ‘hybrid electric’ locomotives – long cycle life, excellent cold temperature performance, fast charge and discharge capability, high charge acceptance, self equalization of charge in large string and in single battery cells, and above all, demonstrated safe operation regardless of temperature – all of these battery property advantages play well in a variety of other markets,” Axion CEO Tom Granville says in a release.
“New initiatives going forward include heavy trucks, charging station applications, residential energy and buffering and storage for wind and solar,” Granville said.
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Source: Axion Power with Fleets & Fuels follow-up