We are very lucky to have the specifications of two battery cells made by the same company and one being LMFP and the other LFP. Thus an opportunity to look at LMFP vs LFP in a like for like scenario. Both cells are from K-Tech New Energy Company Co Ltd (part of Greenway Battery).
K-Tech IMR34145E 14
Lithium Manganese Iron Phosphate (LMFP) Chemistry
- Nominal Capacity = 14 Ah
- Nominal Voltage = 3.7 V
- Maximum Charge Voltage = 4.2 V
- Minimum Discharge Voltage = 2.75 V
- Nominal Energy = 51.8 Wh
K-Tech IFR34145E 15
Lithium Iron Phosphate (LFP) Chemistry
- Nominal Capacity = 15 Ah
- Nominal Voltage = 3.2 V
- Maximum Charge Voltage = 3.65 V
- Minimum Discharge Voltage = 2 V
- Nominal Energy = 48 Wh
- Mass = 0.328 kg
- Dimensions
- Diameter = 33.9mm
- Height = 144.1mm
- Volume = 0.130 Litres
- Mass = 0.309 kg
- Dimensions
- Diameter = 33.9 mm
- Height = 144.1 mm
- Volume = 0.130 Litres
Both cells are in the same size cylindrical can, the LFP chemistry based cell is lighter. Put this toegether with the LMFP having a higher nominal energy and we see that it is a significantly better on volumetric energy density than the LFP cell. However, the gravimetric density is a smaller improvement.
- Volumetric energy density = 398
- Gravimetric energy density = 158
- Volumetric energy density = 369
- Gravimetric energy density = 155
- ACIR = 0.003 @1kHz
- Discharge
- Continuous = 35 A
- C-rate = 2.5 C
- Temperature range = 60°C to -20°C
- Charge
- Continuous = 7 A
- Temperature range = 45°C to -10°C
- ACIR = 0.003 @1kHz
- Discharge
- Continuous = 30 A
- C-rate = 2 C
- Temperature range = 60°C to -20°C
- Charge
- Continuous = 15 A
- Temperature range = 55°C to 0°C
The LMFP based cell has the edge in terms of discharge rate. However, when it comes to charge the LFP cell will charge faster. The advantage the LMFP cell has is that it can be charged when the cell surface temperature is at -10°C.
- Cycle Life
- 2000 cycles
- to 70% SoH
- 0.5C charge / 0.5C discharge
- Cycle Life
- 3500 cycles
- to 70% SoH
- 0.5C charge / 1C discharge
Overall two very interesting cells, brought together in comparison here as we were interested in LMFP vs LFP. If we were to build these into a 48V pack for a bike then we can see perhaps the comparison:
- Configuration = 13s 1p
- Nominal voltage = 48.1 V
- Nominal capacity = 14 Ah
- Nominal energy = 673.4 Wh
- Continuous discharge
- Current = 35A
- Power ~ 1.6kW
- Cell mass = 13 x 0.328 = 4.264 kg
- Cell volume = 1.69 litres
- Configuration = 15s 1p
- Nominal voltage = 48 V
- Nominal capacity = 15 Ah
- Nominal energy = 720 Wh
- Continuous discharge
- Current = 30A
- Power ~1.35kW
- Cell mass = 15 x 0.309 = 4.635 kg
- Cell volume = 1.95 litres
The LMFP cell has a small advantage in discharge power and the higher nominal voltage means less cells required to meet the pack nominal voltage. In reality I think you would use 14 cells in the LMFP pack as that would bring both equal on energy content. The LMFP pack would be only slightly lighter and smaller, but capable of delivering more power. The LMFP pack would take roughly twice as long to charge and the cycle life is considerably less.
At the moment the LFP chemistry wins this overall, but the LMFP offers some advantages that just might be critical for certain applications.
Huge thanks to the K-Tech team for sharing the information. Note:
- English Channel of Greenway is GREENWAY TECHNOLOGY CO., LTD. .
- For our German speaking followers there is Greenway Battery Europe
This post has been built based on the support and sponsorship from: Thermo Fisher Scientific, Eatron Technologies, About:Energy and Quarto Technical Services.
The Battery Cell Database has these K-Tech cells included in the list along with a large number of other cells, formats, chemistries and sizes. Thus allowing you to compare, contrast and look for the right characteristics for you next battery design.