ARPA-E

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josh-on-bike

I’m getting a new website started, quietly posting things until I point my URL to it. How about a greatest hit from last year: riding CUNY’s battery-charging bike at the 2012 ARPA-E Energy Innovation Summit. You can find me in this photoset alongside other luminaries like Bill Clinton, Bill Gates, and Nancy Pelosi.

The bike charges the 4 flow-assisted Ni-Zn batteries on the table. Each battery is 35 Wh, so that’s 0.14 kWh total. The two battery electrodes are actually zinc (Zn) and nickel oxyhydroxide (NiOOH), giving the cell a nominal potential of about 1.8 V. The benefit of these batteries is that they last a long time, being able to cycle at 100% capacity more than 3000 times. There are a few tricks to doing this. One is to have the electrolyte flowing, which is why we call it a “flow-assist” battery.