NCM 712 by LG Chem: E66A and E78 battery cells in detail
While most battery cell makers have been adopting NCM 811 as their preferred battery technology for energy dense cathodes, LG Chem bet heavily on mass production of NCM 712 battery cells.
NCM 811 offers better energy density and battery cells can easily reach 300 Wh/kg, but NCM 712 offers lower cost by using less nickel and more manganese. At the cell level the cost of NCM 811 is currently estimated at around 90 euros per kWh, while NCM 712 is estimated at around 80 euros per kWh.
We now know for sure that the South Korean battery cell maker has at least two different NCM 712 battery cell models. The E78, which is a long battery cell aimed for more modern electric cars with flat and simpler battery packs and the E66A, which is a smaller battery cell better suited for electric cars with non-flat battery packs.
The first energy dense battery cell from LG Chem was the LGX E63, made with a NCM 622 cathode. Previously, pouch battery cells from LG Chem had very poor energy density.
LG Chem LGX E63
- Nominal Capacity: 65,6 Ah (discharged at 21,6 A) – 64,8 Ah (discharged at 32,5 A)
- Minimum Capacity: 64,6 Ah (discharged at 21,6 A) – 63,8 Ah (discharged at 32,5 A)
- Nominal Voltage: 3,6 V
- Charging Voltage: 4,2 V
- Thickness: 11,5 mm
- Width: 125 mm
- Height: 325 mm
- Volume: 0,4671875 L
- Weight: 964,9 g
- Volumetric Energy Density: 492-505 Wh/L
- Gravimetric Energy Density: 238-245 Wh/kg
- Chemistry: NCM 622
This was the first battery cell to give the Renault ZOE a decent range with a 41 kWh battery in late 2016, almost doubling it from the previous generation.
LG Chem E66A
- Nominal Capacity: 65 Ah
- Minimum Capacity: 63,5 Ah
- Nominal Voltage: 3,657 V
- Nominal energy: 237,7 Wh
- Minimum energy: 232,2 Wh
- Thickness: 11,7 mm
- Width: 104 mm
- Height: 350 mm
- Volume: 0,425880 L
- Weight: 897 g
- Volumetric Energy Density: 648 Wh/L
- Gravimetric Energy Density: 259 Wh/kg
- Chemistry: NCM 712
The E66A was made to be a direct replacement for the E63 battery cell. Capacities are very similar, but dimensions and weight are lower. This battery cell is used in the battery pack of the Porsche Taycan, which doesn’t much sense. The large and flat battery pack of the Porsche Taycan could benefit from the usage of longer cells such as the E78.
While not sure, I think that this battery cell is also used by the Renault Twingo Electric and the latest versions of the Hyundai Kona Electric and Chevrolet Bolt EV.
LG Chem E78
- Capacity: 78 Ah
- Voltage: 3,65 V
- Length: above 500 mm (exact dimensions aren’t known)
- Weight: 1.073 g
- Gravimetric energy density: 265 Wh/kg
- Chemistry: NCM 712
This larger battery cell was made to be used in more modern electric cars that have flat and simpler battery packs, such as the new Volkswagen ID family with its MEB platform. Nonetheless, it’s also used by the new generation Renault ZOE.
Larger battery cells allow to assemble simpler high capacity battery packs, by requiring less cells and modules.
Anyway, LG Chem will soon be replacing NCM 712 with NCMA battery cells, which offer similar energy density but are much safer.