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INTRO: As long as I can remember, I've been obsessed with cars. Growing up in the 60's, there was no shortage of cool new cars to keep up with. In high school in the 70's, I read an article in Popular Mechanics about a car a hobbyist built, with an electric motor, a ton of lead-acid batteries, and a very small jet turbine motor hooked to an electric generator. This was obviously the future. Of course, I also knew Jet Packs were just around the corner.
So I was enthralled to see the Volt being developed, some 40 years after I first saw the idea of an electric car with an on-board generator.
But the Volt and the pure electrics being produced are never going to achieve widespread popularity until two things happen. The price of a battery pack has to come way down, and the energy density of the packs has to go way up. I wasn't holding out much hope for this as most advances in battery tech the last 40 years have only been incremental, not game-changing.
Then I saw the first article in this blog, about the breakthrough at Stanford in 2007, showing the huge potential of Lithium Ion batteries if we could just get silicon to work in place of carbon for the anode. At that point, I started collecting articles about battery breakthroughs, and soon realized many many companies are pursuing this full tilt, and we should actually see huge gains by mid-decade. I present this collection here for your enjoyment.
Please refrain from turning this into a "I hate electric cars" discussion, or a GM bail-out discussion, or a political discussion. Sorry, not interested. This is simply a BATTERY BREAKTHROUGH blog, and any off subject remarks will be removed. Thank you.
New Lithium Sulfur design with solid electrolyte.
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Hal's battery blog 
Hi Hal . . .
I found your blog via the above quoted Scientific American web article. I’m not sure if you are aware that there a number of entities currently working on lithium sulfur secondary (ie: rechargeable) cells. ORNL certainly has something to brag about, but a consortium at the University of Arizona in Tucson has also been working hard in this endeavor . . .
http://uanews.org/story/better-batteries-from-waste-sulfur
Also, a British concern, Oxis Energy, appears to on the verge of supplying a commercial lithium sulfur cell . . .
http://www.oxisenergy.com/
There’s a lot to like with lithium sulfur . . . extraordinary energy density and it’s constructed with materials that are cheap/plentiful. If it can be done in larger scale with the solid electrolyte (ORNL’s ace in the hole,) this will mean not having an expensive/complex/heavy thermal management system to prevent thermal runaway. This is a necessity in automotive applications with current lithium ion cells.
What everyone involved with lithium sulfur research seems to be working on at the moment is the number of charge cycles the cells can take. Until recently, it was only 5 or 10 times before the battery was ready for the trash heap (OK . . . recycle heap.) But this is what everyone above has now seemed to move beyond. We’re now hearing about 500 or more charge cycles without cell degradation. If they can get it up to a repeatable 2000 charge cycles under a variety of temperature extremes, they’ll have a commercially viable product that will allow the the retirement of now-current lithium ion technology.
thanks for the links Benjamin. Great stuff.
I don’t know if anyone here can answer this, but I’m going to ask anyway. The article says that the LiS cell produces 1200 mAh/g. It says this is about 4x the density of Li-ion. But the Envia cell holds the record for Li-ion energy density with 400 wh/kg. Now, being that watts = volts x amps, and Li-ion cells are around 4v, that would mean the Envia is only about 100 Ah/kg. And Ah/kg = mAh/g, right? That would give the LiS cell 12x the energy density of the best Li-ion! Did I screw up my math, or did somebody else?
There are a few reports in the literature describing novel Li/S cells with silicon-based anodes. I am wondering whether this could be combined even with a solid electrolyte…
Russian Journal of Electrochemistry, http://dx.doi.org/10.1134/S102319351306013X
DOI: 10.1134/S102319351306013X