March 13, 2013 – Vol.17 No. 52
NICKEL ZINC AS LITHIUM ALTERNATIVE?
by Bruce Mulliken, Green Energy News
Don't put all your eggs in one basket, as the saying goes. Right now, electric and plug-in hybrid vehicle builders are mostly steering towards lithium-ion batteries – in various electro-chemistries – for their car and truck offerings. Apparently these companies are run by gamblers, since there's no guarantee that lithium-reliant batteries will pan out and be at the core of clean cars worldwide.
The risks are enormous for the whole clean car industry. One failed car line due to lithium battery "issues" could bring the entire battery electric vehicle movement to an end, not to recover for decades. "See, we told you so!", will say skeptics of plug-in cars and trucks.
Those "issues" are no laughing matter and should be taken seriously by all invested. Aside from safety, as illustrated by Boeing's Dreamliner Li-ion battery problem, along with the difficulty in obtaining this relatively rare metal, "issues" mostly revolve around money, that is, the cost of those lithium-dependent batteries. If costs don't drop many fold, the vehicles, whose high prices are determined their lithium-ion battery packs, may be sent to the graveyard of failed technologies. The issue of cost comes down to the battery manufacturers.
While the costs of manufacturing Li-ion batteries are only known by the bean-counters and management of individual companies, some of the costs are certainly related to the complexity and difficulty of manufacturing the batteries. And, along that note, manufacturing processes are a closely guarded secrets, so you'll find no detailed white paper as to how and what processes are used by each manufacturer. Production of cells must be extremely expensive, even when battery cells are assembled in nations with very low labor costs. In other words making lithium-ion battery cells isn't easy and if it isn't easy it won't be cheap no matter how cheap low skilled labor gets.
With hundreds of cells per lithium-ion battery pack, costs will remain high unless there's some manufacturing breakthrough that allows allows cells to be assembled in the blink of an eye almost totally by machines. We'll know when that breakthrough comes when cell prices plummet.
It's a little crazy to carry around a whole basket of eggs waiting for a breakthrough. A stumble can come at any time. Forward thinking vehicle developers should be looking for battery alternatives - just in case. Zinc-air is a possibility and batteries are available commercially for testing. Yet, while some companies claim zinc air chemistry is electrochemically rechargeable, there doesn't seem to be any available on the market. Another possibility is Thomas Edison's favorite, Nickel-Zinc chemistry (patented first in 1901). Slowly, with improvements since then, this electrochemistry has coming back to life with PowerGenix, of California, offering small AA and AAA sizes (with charger, but with larger car battery-sized units being built and tested including substituting NiZn in a Toyota Prius for its Nickel-metal hydride (NiMH) battery pack.
Both Nickel and Zinc are easily obtainable on the planet and require no special needs on the production line (to the point where batteries can be made with existing equipment used for other electro-chemistries.) The batteries won't catch fire under any circumstances. Further, the batteries are easily and endlessly recycled, something that can't be said for lithium-ion.
If there's a drawback it's less power and energy density and less voltage per cell than lithium-ion as well as fewer times the batteries can be recharged. (Even those drawbacks are debatable among battery experts.) Still, at substantially less cost, as much as half, they're worth a look. The batteries are more easily compared with NiMH, but at less cost there as well. PowerGenix thinks its batteries are better suited to hybrids than plug-in electrics because of the similarities in performance to NiMH batteries. However, some of the longest distances ever recorded in electric vehicles were equipped with NiMH batteries, so there you go.
Electronics Bus has a good comparision of NiZn vs Lithium-Ion and other chemistries.
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