OK, I'm starting to get the picture.
An extended metaphor to explain lithium ion battery degradation.
By Dave
Battery = Theater
Anode = Lobby (carbon)
Cathode = Band on Stage (Lithium with other stuff)
Lithium ions = Chemically impaired stoners
Electrons = Stoner girlfriends
High resistance pathway = Rain
Copper conductors = BFFs with umbrellas
Electrical load (motor) = Pimply geeks
Electrolyte = the audience
Charged particle driving fields = Security, young love
Reacted electrolyte film = audience wall at lobby door
Initial conditions: Charged theater.
The band is playing. The stoners are stuck in the lobby as intercalated carbon.
They want to be with the band on stage.
Initially, the audience will let them through, but won't let their girlfriends go with (some object to the tats, some are rabid misogynists.)
Bad news, the girls are stuck in the lobby trying to get to their boyfriends on stage.
Good news, they can go outside and in through the stage door in back.
Bad news, it's raining outside.
Good news, the BFFs form a line with their umbrellas to facilitate true love and get the girlfriends from the lobby to the stage door through the rain.
Bad news, the pimply geeks crash the BFF line and get in the way. They are extremely jealous and don't understand why the GFs hang with the scrawny loser stoners not them.
Good news, the GFs are armed with handbags and flip knives and can threaten or drive the geeks out of the way (useful work.)
When the GFs and the stoners are all on stage, no more work can be done, the battery is discharged.
But Security can push the stoners back through the crowd to the lobby to re-charge the scenario. Girlfriends follow outside (geeks out of the way.)
Things go bad when the theater gets hot.
The crowd gets sweaty and smelly and starts to object to the stoners movement from the lobby to the stage.
They form a barrier at the lobby door and won't let the lithium ions thru.
Everything slowly grinds to a halt because the stoners can't get to the stage, the girlfriends are stuck wherever the boyfriends are and the geeks outside don't get pushed around any more.
Even when the theater cools down, the audience remembers how the stoners insulted them and won't let the scumbags pass.
If you don't get the theater hot, the audience will let the stoners pass no prob.
If you leave the stoners on stage (theater uncharged), they don't smell up the lobby and the audience doesn't form the impediment to movement but you don't move any geeks outside either.
So I'm trying to keep my Leaf at around 50% SOC as a balance between usefulness (charged) and longevity (cool and discharged.)
You gotta have some stoners in the lobby (charged battery) or the car isn't very useful.
But the audience will, specially when it's hot, build a permanent wall against stoner movement and the theater loses its ability to push the geeks around with girlfriends following stoners. In the words of the great late 20th century philosopher, Ted, who said, "Whoa...Dude."
Anyone want to correct the model here like how it applies to degradation from depth of discharge
or propose units for stoner girlfriends (e.g. the Courtney?)