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Originally Posted by james
I didn't think the problem with LION was cycles, but a deterioration with time that happens even the battery isn't used at all.
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Not all lithium-ion batteries have the same chemistry - there are at least a dozen different variants out there now. Admittedly, most of the older ones and in fact even the majority of the ones most widely used today certainly do have longevity (with time) issues, hence the concern of many. However some recent types are vastly improved.
To give a brief synopsis of recent progress in lithium-battery chemistries, here is my personal pick of the bunch:
1)
Valence Saphion - these are being used in the current
plug-in Prius project, helping it get 150+ mpg during commuting distances. Check out their
excellent video, showing how Valence's phosphate chemistry is inherently safe and can't be made to catch fire, even when pierced, crushed, burnt or shot with high velocity rounds! Other bonuses are big power output and a claim that they should last the life of the plug-in Prius conversions, cycle and time-wise, but poor energy density of only about 100 Wh/kg.
2)
Toshiba 1 minute charge battery - these batteries can be charged to 80% full in 1 minute flat, work at -40oC and incredibly lose only 1% of their capacity after 1,000 deep discharge cycles (figure 200k miles in an EV before you begin to notice a loss of capacity!) They use nano-sized particles to achieve this. Already planned for future hybrids.
3)
Polyplus lithium sulphur - still in the development stage, but existing cells are
420 Wh/kg and they reckon they can eventually hit
600 Wh/kg. What does that mean to you? At 420 Wh/kg a 200kg pack would store 84 kWh which is enough to travel 400 miles in an EV between charges.
Sion also have LiS cells at 350 Wh/kg which have already been shown in laptops.
4)
A123 nanotech batteries - sound to me like they combine the benefits of (1) and (2) into one battery! Seem to have a phosphate chemistry (so safe, which the auto industry likes) and also nano-sized particle material at the electrodes, which means huge power output and minimal losses. Ten times longer lived (time-wise) than normal LiIon too.
5)
Polyplus Lithium-air - the lithium-air couple has a theoretical energy density of 11,600 Wh/kg! Accounting for typical packaging and other compromises, practical Li-Air batteries could eventually have energy densities of up to 3,000 Wh/kg. That would mean adding a 25kg pack by hand at the "filling-station" for 375 miles silent EV-mode range before the next stop!
There's a lot going on in lithium right now and only a matter of time before it makes the big time in vehicles. Indeed it has already been used in Japan-market-only vehicles for some time now!
