[EE]:: How do Lithium Ion batteries die? - excellent 'lecture' ... & related

[RussellMc]

April 2016 transcript of an excellent lecture on LiIon batteries that gives
useful insight into lifetime mechanisms.
Shortly after this transcript was published the lecturer (Prof Jeff Dahn)
was hired by Tesla.

Some of his suggestions and concepts could (probably) be applied to perform
similar measurements with suitable precision using much simpler equipment.


https://batterybro.com/blogs/18650-wholesale-battery-reviews/103090502-why-do-lithium-ion-batteries-die-long

They say:

This is a very long (10,000 word, 60 image) blog post transcribing a
lecture by professor Jeff Dahn <http://www.dal.ca/diff/dahn.html>from
Dalhousie University titled "Why do lithium-ion batteries die, and can they
be immortal?"

Not only is Jeff at the top of his field (he seriously is one of the
leading figures in lithium-ion batteries), he also has a knack for making
complicated things simple. The subject at hand really is technical, but
anyone should be able to follow along thanks to Jeff's incredible
understanding of the subject matter.
__________________________________________

How are 18650 batteries made:

https://batterybro.com/blogs/18650-wholesale-battery-reviews/97472070-mit-video-how-are-18650-batteries-made

Battery bro

https://batterybro.com/

BB blogs - many excellent articles and links

https://batterybro.com/blogs/18650-wholesale-battery-reviews/

[James Cameron]

Thanks, interesting.

Specific electrolyte additives and temperature control in the field
are critical to product longevity.

Paraphrasing a new rule of use; minimise temperature while battery
voltage is high.

Or even simpler; minimise voltage, and minimise temperature.

He describes the underlying causes and methods to test for the
mechanism of degradation. Measuring the heat gain or loss during a
cycle is nice.

[RussellMc]

Post by James Cameron
Thanks, interesting.
Specific electrolyte additives and temperature control in the field
are critical to product longevity.
Paraphrasing a new rule of use; minimise temperature while battery
voltage is high.
Or even simpler; minimise voltage, and minimise temperature.
He describes the underlying causes and methods to test for the
mechanism of degradation. Measuring the heat gain or loss during a
cycle is nice.

I'm not intuitively comfortable with his assertion that cycle life is well

Post by James Cameron
(if not linearly) correlated with coulombic efficiency.

LiFePO4 at least start at somewhere over 99% when new and IMPROVE with time.
(Note that although Li cell charge/discharge energy efficiency is high
compared to most otrher systems, coulombic and energy efficiencies do not
track well, alas.)

Russell

[James Cameron]

Post by RussellMc

Post by James Cameron
Thanks, interesting.
Specific electrolyte additives and temperature control in the field
are critical to product longevity.
Paraphrasing a new rule of use; minimise temperature while battery
voltage is high.
Or even simpler; minimise voltage, and minimise temperature.
He describes the underlying causes and methods to test for the
mechanism of degradation. Measuring the heat gain or loss during a
cycle is nice.

I'm not intuitively comfortable with his assertion that cycle life is well
(if not linearly) correlated with coulombic efficiency.
LiFePO4 at least start at somewhere over 99% when new and IMPROVE with time.

Hmm, my reading was the reverse. Coulombic inefficiency as a result
of the undesired reactions. These reactions may decrease in extent
after a few cycles, but they have begun.

Post by RussellMc
(Note that although Li cell charge/discharge energy efficiency is high
compared to most otrher systems, coulombic and energy efficiencies do not
track well, alas.)

p.s. "surface" is often rendered as "service" during the
transcription.