kingjamez
Member
I wrote a long rebuttal to this, but it was quite snippy. So I’ll just say this.Look.
LiNiCoAlO2 cathode (~9% Co), graphite anode is what they are using and are working to get rid of the Cobalt on that Anode, however as we know Cobalt is an excellent stable storage medium when sandwiched with Li.
1C; 2.50V cut off. Discharge current above 1C shortens battery life. As well as the C-Rate charge over 1C tears a battery up. It does matter what battery you use or its capacity....lithium recycle rate drops to nothing when being charged or discharged above 1C. That holds true for all batteries that utilize Lithium.
So...with that said..... The more batteries you have in a pack allows you to pull 1C out of more batteries at once. For instance if you had a single gigantic cell at 75kwh...you could only pull 1C out of it. If you have 3000 cells @ 75kwh in sum...you can achieve at least 30C if you properly keep your parallel / serial / cooling circuits configured properly.
One reason I believe Tesla uses round cells as apposed to flat cells as in the Leaf and other EV's is because there is more surface area to cool thereby being able to keep the C-rate up.
The number of cells matters dramatically when talking about C rate because of temperature. You can't pull high C rates from a single battery because you won't be able to cool the inner-core. Even if a single cell can charge and discharge at 3C you won't be able to prevent thermal runaway of Lithium because you won't be able to cool it.
Now that we are a little further in the weeds.....google the properties of controlled lithium when cobalt is on the anode.
You have a fundamental misunderstanding of how chemistry affects the C rate of the cell. This is likely due to the fact that you also have a fundamental misunderstanding of how C works. You possibly don’t understand how parallel cells affect the potential output of a pack.
The cells in a Model S are around 3ah each. My S75D charges at 93kW and discharges at over 150kW. Think about how that relates to your position.
Your googling doesn’t matter because no-one has the chemistry specs on the 2170’s in the 3.
-Jim