JejuSoul
Posts: 1157
Joined: Wed Jul 08, 2015 6:47 am
Location: Jeju
Contact: Website

Re: Comparing Battery Chemistries

Sat Mar 10, 2018 3:55 am

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This post will give details on the NMC 622 cells currently being used in the Chevy B olt and 40kWh Nissan L eaf. NMC 622 has a higher energy density than previous chemistries. One problem though seems to be the higher energy density of the cathode, does not allow for a similar increase in charging power because of limitations in the anode.

Update: this also seems to be the cell used in the new Kona EV.

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Using info from this article - Jaguar and Chevy have LG in common we can find the stats for the B olt EV cells.

Found this battery cell on sale at Alibaba - 3.7V 60Ah lithium polymer rechargeable battery for EV power tools

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Having the exact size, weight and capacity of this cell will allow us to compare this current generation cell with the soon to be released NCM811 cell.

This cell appears to be the same one used in the Chevy B olt EV. - see Inside the factory building GM's game-changing Bolt EV

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Info for the new Nissan L eaf can be found here - 2018 Nissan Leaf battery real specs

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there's an interesting comment about charging speeds here - Tesla Forum: 2018 Nissan Leaf - $29,990. 40kWh battery
Renim wrote:...
increase in range capacity comes with a decrease in max charge rate.
...
the core reason is that the anode powder (carbon) has a strong inverse relationship between charge rate and safety (plating)
...
Last edited by JejuSoul on Sat Jun 02, 2018 6:15 am, edited 1 time in total.
The codes for using Torque Pro can be found by clicking the link in the website icon under my user name on the left.

JejuSoul
Posts: 1157
Joined: Wed Jul 08, 2015 6:47 am
Location: Jeju
Contact: Website

Re: Comparing Battery Chemistries

Sat Apr 21, 2018 6:56 pm

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At the recent EVTrend Motor Show in Seoul LG Chem displayed these 4 cells.
They didn't say what the last 3 are used for, but from the label color on the cell, the distance it travels and where it was made I have made the following guesses.
1/ Hyundai I oniq - Made in Korea.
2/ Chevrolt B olt - Made in Korea. - yellow sticker
3/ Jaguar I-P ace - Made in Korea ? Poland ?. - green sticker and power tabs offset.
4/ ??? Hyundai K ona or Audi E-T ron

see Audi e-tron vs Jaguar I-PACE battery pack comparison

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I believe 2,3,and 4 are all the same dimensions and are all 60Ah, but presumably the chemistry is slightly different.
These 3 are all are the NMC622 chemistry, LG Chem has yet to start NMC811.

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The battery in our Kia Soul EV is also probably NCM 622. It has never been confirmed but this article SK Innovation rolls out advanced batteries states :

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SK Innovation was the first in the world to succeed in the commercial production of advanced NCM 622 batteries.


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The battery cell used in the I oniq EV is probably LG Chem's LQ 1729-A2 43Ah Cell.
see: PDF datasheet for Lithium-Ion 43 Ah L3 LG Chem – LQ 1729-A2 Cell

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192 cells * 43Ah * 3.75V = 30.96kWh which confirms that the total capacity of the I oniq EV is 31kWh.
The energy density of a single cell is 161.25 Wh / 0.966kg = 167Wh/kg
Hence it is probably not NMC622.

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JejuSoul
Posts: 1157
Joined: Wed Jul 08, 2015 6:47 am
Location: Jeju
Contact: Website

Re: Comparing Battery Chemistries

Sat Jun 02, 2018 7:19 am

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Reading through this thread again I want to make a guess about SK Innovation's naming scheme for their cells.

I think. (speculation for now - will add details as I find them)

E250 cell is a 25Ah cell. Perhaps this is the cell used in the Kia Ray EV. It is LMO / NMC. But the Ray EV uses 50Ah cells. I was hoping that they might be cell pairs.

E375 cell is a 37.5Ah cell. This is the cell used in the Kia Soul EV from June 2014 to June 2017. It is NMC622. (Called Nickel Rich or LMO Free)

E400 cell is a 40.0 Ah cell. This is the cell used in the Kia Soul EV from June 2017 onwards.


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SK Innovation has a patent for a 25Ah cell here - Electrolyte for Lithium Secondary Battery and Lithium Secondary Battery Containing the Same
...A film separator made of a polyethylene (PE) material and having a thickness of 25 μm was stacked between the prepared electrodes, and a cell was configured using a pouch having a size of 8 mm×270 mm×185 mm (thickness×length×width), followed by injection of the non-aqueous electrolyte, thereby manufacturing a 25Ah-class lithium secondary battery for an electric vehicle (EV).

Performance of the 25Ah-class battery for an electric vehicle (EV) manufactured as described above was evaluated as follows. Evaluation items are as follows...


A research paper discussing the Ray EV battery temperature dynamics here -
Battery Pack Temperature Estimation Model for EVs and Its Semi-transient Case Study
It states the Ray EV battery cell as 50Ah, 3.7V
We know the Ray EV has 88 cells in 12 modules. 50Ah * 3.7V * 88 cells = 16.28kWh
But it could be there are 88 cell pairs where each cell is 25Ah

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There's a really good report on NMC811 here - What do we know about next-generation NMC 811 cathode?
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