Monday, September 18, 2006

Lithium ion batteries

JORDAN ROBERTSON of AP noted the following of lithium ion batteries:

The chemical reaction that occurs in lithium-ion batteries is complicated. But the basic reaction involves coupling a lithium-carbon compound (which serves as the negative electrode [anode]) with cobalt oxide (which serves as the positive electrode[cathode]), according to K.M. Abraham, a lithium battery consultant and visiting chemistry research professor at Northeastern University in Boston.

Of the danger:

Abraham said the biggest threat is the possible penetration of the thin barrier made of synthetic material - about as thick as a sheet of paper - that separates the two electrodes and prevents the quick release of energy.

The nature of the "lithium-carbon compound" is a bit complicated. I wrote a paper on it: “The Interrelationship of hydrogen-containing carbon and lithium,” Carbon, 34, 671-672 (1996). The idea that carbon-lithium would be of interest as an anode material was discussed in: “Intercalation Compounds of Graphite, Annual Rev. Mater. Sci., 6, 181 (1976).

Of the danger of Google searches, whether done by Dateline on the ingredients of Moisturol (aka NesQuik) or anybody else, note the following text found via a Google search:

From http://www.military-information-technology.com/print_article.cfm?DocID=990 :

Safety is another important issue in battery development. Most lithium-ion rechargeable batteries use carbon as the cathode and alternate layers of cobalt oxide and lithium as the anode. The exchange of lithium ions between the cathode and anode recharges the battery.

But cobalt oxide is sensitive to heat spikes under high processing demands. Heat spikes or a short inside a cobalt or metal-oxide battery can trigger thermal runaway, which, when caught on fire, feeds itself with its own oxygen.


[IPBiz post 1998]

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