How do Lithium batteries work?

Squeaky the Squirrel

http://shkrobius.livejournal.com/398842.html?nojs=1

On ignorance

If you are a scientist, you confront ignorance as soon as you open your eyes.

For example -- I am typing this post on a laptop computer that is powered by a lithium battery. No one has the slightest idea how and why it works.

Metallic lithium can intercalate between the graphene sheets in graphite in the anode. This anode is in contact with the electrolyte containing lithium salt. It needs to be an unreactive solvent that remains liquid over a wide temperature range, which narrows the choice tremendously. Initially, propylene carbonate was the electrolyte; that was a serious problem. The electrolyte diffused between the graphene sheets and weakened the anode. Li batteries were inefficient and dangerous.

In the early 1990s, it was discovered that, counterintuitively, using ethylene carbonate, which is a smaller molecule, solves this problem; only then Li batteries became commercialized. Electrochemical reduction of the solvent produces dense material that passes lithium cations through, but blocks solvent molecules. No such material is formed for propylene carbonate. Li battery can be cycled many times due to this solid electrolyte interface formation; without it, the battery cannot work.

That was 20 years ago. Still no one knows what chemical process yields this material, what is this material, and why a small structural change in the electrolyte makes such a colossal difference in the performance.

Is this right?

The Earl Of Sammich

Cold fusion?

Capt'n Midnight

That's like asking how magnets work.

We know a lot about them and they are very useful but there are some gaps in our knowledge about them. Same is true of some aspects of some of the chemistry used in some lithium cells.

There are lots of different types of lithium batteries with differing chemistry between them https://en.wikipedia.org/wiki/Lithium_battery