Viruses Boost Performance of Lithium-Air Battery Used In Electric Cars 66
rtoz writes "MIT researchers have found that adding genetically modified viruses to the production of nanowires will boost the performance of lithium-air battery used in electric cars. The key to their work was to increase the surface area of the wire, thus increasing the area where electrochemical activity takes place during charging or discharging of the battery (abstract). The increase in surface area produced by their method can provide a big advantage in lithium-air batteries' rate of charging and discharging. Unlike conventional fabrication methods, which involve energy-intensive high temperatures and hazardous chemicals, this process can be carried out at room temperature using a water-based process."
Re:Lithium and water? (Score:4, Informative)
The viruses were used to make manganese oxide (MnO) nanowires, which acted as the cathode material. The catalysts, electrolyte, and lithium comes in later.
Re:Practical use?? (Score:5, Informative)
I wonder why they don't put the minimum threshold higher on batteries. I've heard that completely discharging lithium batteries is really bad for them. But then why not just build in some extra capacity into the battery, and have it refuse to run once it reaches 20%.
That's actually what modern hybrid and EV battery management systems do. They also stop charging at about 80% of max capacity, because it's the top and bottom 20% of charge states where the maximum wear is. So a 100 kwh 1k charge cycle battery might be exactly identical to a 80 kwh 4k cycle battery.
It's generally not done with consumer electronics because they only expect them to last 1-2 years and weight/cost are bigger concerns than longevity.
It should be noted that when they talk about X numbers of 'charge cycles' it's from 0% to 100% even when it comes to applications where they really expect lots of partial charges - cell phones, EVs, and such. So if you charge it up 50%, then 20%, then 30%, that adds up to 1 cycle. Though if they're being honest they rate the expected cycles by the expected duty cycle - LiIon 'likes' partial charges, NiCad doesn't. Lead-Acid doesn't like being discharged, but tolerates being fully or even over charged the best out of the common chemistries.