There's an interesting article in the Oct 10th - 16th issue of The Economist, page 87, entitled "New Batteries required." It deals with new battery technology, ostensibly for the electric vehicle market, but provides a well-rounded summary of the current state of affairs as follows:
The ideal battery would combine low cost with a high specific energy and a long life(determined by the number of times it can be recharged before wearing out). The US Advanced Battery Consortium(USABC), a joint research venturre between Ford, Chryslr, GM and the Department of Energy, has set itself the long-term goal of building a battery that costs only twice as much as current lead-acid batteries, but delivers six or seven times the specific energy--enough to provide a range of 350 miles, about the same as a conventional car with a full tank. "That's the holy grail," says Mark Vergrugge of USABC. The article then goes on to give a general description of several battery types. 1) Nickel-Metal-Hydride(NiMhd), a technology that is used to power PC,'s and that when compared with previous batteries offer a higher specific energy (80 wh/kg), perform better in cold weather, and can be recharged quickly. But they cost four times as much. 2) Lithium-ion, a battery type computers, camcorders, etc., are moving over to with three times the specific energy of lead acid(95 wh/kg). But they are expensive, and lthium is highly reactive. 3) Lith-poly technology, also developed for use in consumer electronics, is a more promising new possibility. It is safer than lithium-ion, promises twice the specific energy, and can be packaged in almost any shape. But it is even more expensive that lithium-ion(my note; I take this to be because no one has been able to mass-manufacture lith-poly thus prices stay high. IF VLNC can mass produce them......then prices should begin to reflect this, eh?). Another contender is 4) zinc-air technology, which offers similar specific energy to lith-poly(around 200 wh/kg) but is available today. The drawback? Rather than being rechargeable like other batteries, zinc-air batteries have to be removed and replenished by chemical processing. This means they are suitable only for niche applications, such as delivery vehicles, where specialist recharging equipment can be installed at a central depot.
Then there are batteries based on molten sodium-sulpher and sodium-nickel chloride, which are being evaluated by Ford, BMW, Mercedes-Benz and others. They too offer impressive capacity, but they also require internal heaters, because they work only at temperatures of 300 degrees Centigrade or so. If the heater fails, the batteries solidify, and stop working. Scarier still are zinc-chloride batteries(which emit chlorin gas during recharging) and zinc-bromide batteries. One zinc-bromide powered EV was involved in an accident and released toxic fumes.... Etc....
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Just an FYI to the thread.
John~ |
