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New All-Solid Sulfur Based Battery Outperforms Lithium Ion
olsmeister writes "The new all-solid battery design uses solid sulfur and lithium, and outperforms existing lithium-ion batteries with four times the energy density. The battery can maintain a capacity of 1200 milliampere-hours per gram after 300 charge-discharge cycles. More work needs to be done, but one would think this new technology could have applications in renewable energy storage, electric cars, and consumer electronics."
"Because lithium-sulfur batteries deliver about half the voltage of lithium-ion versions"
Li-ion is around 3.7V (+-0.4, depending on exact design). So this is about a 1.8V battery. So for a reasonable approximation, multiply by about 7 for a 12v version. That puts a 12v, 1.2AH version at 175g. Plus a little more for the casing. Not bad at all. Add case, and your 30AH battery can be replaced with a five-kilo battery. A bit heavy for a pocket, but but by much.
It's +- a lot more than 0.4V depending on charge. One of the problems with li-ions is the substantial difference between charged and discharged voltages, requiring devices be able to operate efficiently right across the range.
I've seen li-ions/lipo rated from around 3.2 to 3.9 volts nominal, depending just upon the exact design of the cell - there are a few variations of the chemistry in use. They all function much the same, and the vast majority of cells are labeled 3.6 or 3.7.
I'm sure Elon Musk is paying attention to this. He thinks an electric jet would be possible, and this would make that a whole lot easier to achieve. If they can commercialize it in the next couple of years, it would also be just in time to help Tesla develop its next-gen "affordable" EV. I wouldn't be surprised if he and/or Tesla invest in whatever company gets to bring this tech to market.
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What? 1.2Ah per gram, thats like 7g for 12V version, not 175g!
No, it is a function of the battery chemistry. You have LiCoO2, LiMn2O4, LiFePO4, and others, each with different charge voltages. A good read: http://batteryuniversity.com/learn/article/types_of_lithium_ion
Stop that! I'm about to drop dead from laughing too hard!
There is no fricking way that a battery technology in this kind of shape will enter a mass-produced automobile in the next TEN years, never mind two. Portable devices, I'd give 7-8 years if everything goes well. Fifteen years for automobiles, minimum.
Let's count the issues here. The battery is tested only at 60 degrees C, which implies that its performance must suck at room temperature (not surprising--solid batteries tend to do really badly at low temperatures). The battery is showing horrendous wear--75% wear after 300 cycles--good enough to show promise, but nowhere near good enough to be considered for commercialization. The charge rate being tested is 1/10C. which probably means that the battery cannot be usefully charged/discharged unless you take at least 10 hours to bring it up to full charge.
All of these are incredibly hard issues, and only after solve all of them can you get down to the manufacturing process engineering. I'd be impressed if they get to this stage in six years. Then you get to manufacture, test, integrate--and finally you get your first shipping product. Automobiles are a different beast altogether, requiring much more testing, much bigger manufacturing capacity, different control mechanism, looooong design lead time--so add another five years.
They're named the way they are because of their chemistry. An alkaline cell has an open circuit voltage of 1.43V - close enough to the old Zinc-Carbon cell's OC voltage of 1.5V. A lead-acid cell has an open circuit voltage of about 2.1V. 6 of those in series makes 12-ish V. The cell potential between the anode and cathode materials determines their open circuit voltage (see this chart).
Here's a great FAQ on battery chemistries.
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