In proper terms, the Lithium ion, Li+, is chelated by the "Organic"
compounds. Lithium disulfide and Lithium Sulfide are properly
termed "Inorganic" unless you are from a different planet with
alternate element based Life forms (LOL). As mentioned below, the
propylene carbonate, dioxane, and dimethoxyethane are really carriers
and do not themselves have a charge. In theory, these compounds
would not be electrolytes because they themselves are not
charged. They may be polar, and that characteristic permits them
to solubilize polar compunds as well as charged ions. The
electrodes, e.g. carbon or other related metals are just the location
where electrons are given up or accepted by the oxidation or reduction
reactions. It is the combinatin oxidation and reduction reaction that
gives a cell it's overall potential (voltage). In order for Lithium to
give up it's electrons the Fe (iron) must accept the electron.
Only when all the FeS2 is used up, or likewise all the Li available
releases the electrons will the cell reaction hit an equilibrium and
the battery be "Used Up". Recharging is the reverse the
reaction, however due to the content of the cell components, reversal
may not be the reverse of the electricity generating process.
Batteries are made with the electrolytes as a "Paste" for a variety of
reasons, and ion diffusion in the paste is controlled by temperature
and hence time. That is why if you leave a battery for a while
after discharge it seems to come to life again, but not for long.
The solvents, dioxane, propylen carbonate and dimethoxyethane are used
for their low toxicity and solubility for dispersion, in water if you
are an environmental person.
BTW, water, which we say is an electrolyte is both a polar as well as
produces ions. Within water as a solvent, water dissociates
into solublized (H2O solvent) H+ (protons, an acid) and OH- ions
(hydroxide base) to a large enough extent to conduct electricity.
If the reader will consult the URL for Li polymer descriptions, they
will see the the 3.0+ volt reduction potentials.
As an aside, what we really should be using is room temperature
molten salt batteries. Their elements and reactions are so
flamable that they are extremely dangerous. However, due to their
extremely high energy density, as well as their flamablilty and
explosive nature, they are used in relatively short duration electronic
applications, i. e. cruise missles. When they explode the battery
itself becomes part of the explosive and flamable destructive power. If
you think the Li polymer batteries we have explode, you should see these
electrolytes go up when exposed to air.
Grins!
Chris
<SNIP from my previous post URI>
The Lithium-Iron chemistry deserves a separate section because it is one of a handful of lithium metal systems that have a 1.5 volt output (others are lithium/lead bismuthate, lithium/bismuth trioxide, lithium/copper oxide, and lithium/copper sulfide). Recently consumer cells that use the Li/Fe have reached the market, including the Energizer. These have advantage of having the same voltage as alkaline batteries with much more energy storage capacity, so they are called "voltage compatible" lithiums. They are not rechargeable. They have about 2.5 times the capacity of an alkaline battery of the same size, but only under high current discharge conditions (digital cameras, flashlights, motor driven toys, etc.). For small currents they don't have any advantage. Another advantage is the low self-discharge rate–10 years storage is quoted by the manufacturer. The discharge reactions are:
Both Iron sulfide and Iron
disulfide are used, the FeS2 is used in the Energizer. Electrolytes are
organic materials such as propylene carbonate, dioxolane and
dimethoxyelthane
The Lithium-Iron chemistry deserves a separate section because it is one of a handful of lithium metal systems that have a 1.5 volt output (others are lithium/lead bismuthate, lithium/bismuth trioxide, lithium/copper oxide, and lithium/copper sulfide). Recently consumer cells that use the Li/Fe have reached the market, including the Energizer. These have advantage of having the same voltage as alkaline batteries with much more energy storage capacity, so they are called "voltage compatible" lithiums. They are not rechargeable. They have about 2.5 times the capacity of an alkaline battery of the same size, but only under high current discharge conditions (digital cameras, flashlights, motor driven toys, etc.). For small currents they don't have any advantage. Another advantage is the low self-discharge rate–10 years storage is quoted by the manufacturer. The discharge reactions are:
| Type | Reaction | Nominal Voltage | Range |
| FeS2 Version | 2 FeS2 + 4 Li —> Fe + 2Li2S | 1.6 Volts | 1.6-1.4 V |
| FeS Version | FeS + 2Li —> Fe + Li2S | 1.5 Volts | 1.5-1.2 V |
-------- Original Message --------
Subject: [RCSE] EverReady's Answer to the Lithium 1.5 V Cell Question
From: [EMAIL PROTECTED]
Date: Fri, October 27, 2006 2:05 pm
To: [email protected]
To confirm my earlier post that lithium was probably a component of the electrolyte and not truly a controlling element of the electrochemical reaction (which determines voltage), I contacted EverReady's help line. They confirmed that the lithium in their AA batteries was part of an "organic lithium based electrolyte, specifically lithium disulfide". There you have it, it is part of the electrolyte, not electrode, thus the conventional electrodes determine the 1.5 V per cell, and the electrolyte just allows the electrodes to last much longer than conventional (more corrosive) electrolytes before it wears out.As a side note, I have used the lithium AA's in a scanner I use for my XC vario. Those batteries clearly outlived anything else I have put in the scanner, by an (estimated) 10 x lifetime of an alkaline. Well worth the extra cost.Keep in mind, these will not be rechargable in the sense that NiCd, NiMH or LiPoly can be recharged to full capacity.Jim Thomas
