[FoRK] Super batteries, Electric cars with fast-swap batteries
Stephen D. Williams
sdw at lig.net
Wed Mar 18 01:14:48 PDT 2009
We'll see how long it takes to get to market.
> The results are pretty astonishing. At low discharge rates, a cell
> prepared from this material discharges completely to its theoretical
> limit (~166mAh/g). As the authors put it, "Capacity retention of the
> material is superior." Running it through 50 charge/discharge cycles
> revealed no significant change in the total capacity of the battery.
> But the truly surprising features of the cell came when the authors
> tweaked the cathode to allow higher currents to be run into the cell.
> Increasing the rate by a factor of 100 dropped the total capacity down
> to about 110mAh/g, but increased the power rate by two orders of
> magnitude (that's a hundred-fold increase) compared to traditional
> lithium batteries. Amazingly, under these conditions, the charge
> capacity of the battery actually increased as it underwent more
> charge/discharge cycles. Doubling the charge transport from there cut
> the capacity in half, but again doubled the power rate. At this top
> rate, the entire battery would discharge in as little as nine seconds.
> That sort of performance had previously only been achieved using
> The State of Hawaii and the Hawaiian Electric Company on Tuesday
> endorsed an effort to build an alternative transportation system based
> on electric vehicles with swappable batteries and an “intelligent”
> battery recharging network.
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