Chemical processes in the Li–S cell include lithium dissolution from the anode surface (and incorporation into alkali metal polysulfide salts) during discharge, and reverse lithium plating to the anode while charging. This contrasts with conventional lithium-ion cells, where the lithium ions are intercalated in the anode and cathodes. Consequently Li-S allows for a much higher lithium storage density. Polysulfides are reduced on the cathode surface in sequence while the cell is discharging:
8 → Li
8 → Li
6 → Li
4 → Li
Across a porous diffusion separator, sulfur polymers form at the cathode as the cell charges:
2S → Li
2 → Li
3 → Li
4 → Li
6 → Li
8 → S
These reactions are analogous to those in the sodium–sulfur battery.
Most use a carbon/sulfur cathode and a lithium anode. Sulfur is very cheap, but lacks electroconductivity. Sulfur alone is 5*10−30 S cm−1 at 25°C. A carbon coating provides the missing electroconductivity. Carbon nanofibers provide an effective electron conduction path and structural integrity, at the disadvantage of higher cost.
Each sulfur atom can host two lithium ions. Typically, lithium-ion batteries accommodate only 0.5–0.7 lithium ions per host atom.
Read more about this topic: Lithium–sulfur Battery
Other articles related to "chemistry":
1918), German winner of the Nobel Prize in Chemistry for pioneering work in the area of organometallic chemistry ...
... A variety of bidimensional phases can be detected, each separated by a phase transition ... During the phase transition, the surface pressure doesn't change, but the area does, just like during normal phase transitions volume changes but pressure doesn't ...
... The research activities of the Institute of Chemistry of the Slovak Academy of Sciences are aimed at the chemistry and biochemistry of saccharides ...
... International Union of Pure and Applied Chemistry Royal Australian Chemical Institute Royal Netherlands Chemical Society Royal Society of Chemistry Society of ...
... Stanley was born in Ridgeville, Indiana, and earned a BS in Chemistry at Earlham College in Richmond, Indiana ... in chemistry two years later ... His later accomplishments include writing the book "Chemistry A Beautiful Thing" and achieving his high stature as a Pulitzer Prize nominee ...
Famous quotes containing the word chemistry:
“...some sort of false logic has crept into our schools, for the people whom I have seen doing housework or cooking know nothing of botany or chemistry, and the people who know botany and chemistry do not cook or sweep. The conclusion seems to be, if one knows chemistry she must not cook or do housework.”
—Ellen Henrietta Swallow Richards (18421911)
“If thought makes free, so does the moral sentiment. The mixtures of spiritual chemistry refuse to be analyzed.”
—Ralph Waldo Emerson (18031882)
“The chemistry of dissatisfaction is as the chemistry of some marvelously potent tar. In it are the building stones of explosives, stimulants, poisons, opiates, perfumes and stenches.”
—Eric Hoffer (19021983)