LMFP (lithium manganese iron phosphate)

LMFP adds manganese to the LFP cathode to raise its voltage and energy density while keeping much of LFP's stability. Public automotive ageing data for LMFP is still limited, so any lifetime model is experimental.

What LMFP is

LMFP is a variation on lithium iron phosphate in which part of the iron is replaced by manganese. Manganese raises the cell's operating voltage, which increases energy density compared with standard LFP. The aim is to bring phosphate-based chemistry closer to nickel-based cells in range while retaining good thermal stability and lower material cost.

LMFP cathodes are sometimes blended with other cathode materials. Manufacturers use different compositions, so 'LMFP' can describe a range of designs.

What is known about ageing

Because LMFP is structurally related to LFP, it is reasonable to expect broadly similar ageing mechanisms on the anode side: SEI growth driven by temperature and SOC, and lithium plating risk when charging cold or fast. LFP calendar and cycle studies are therefore the closest well-documented reference.

The manganese and the higher voltage do introduce differences. Manganese-containing cathodes can be affected by manganese dissolution under some conditions, and the shape of the voltage curve differs from LFP. How these factors play out over many years in vehicle packs is not yet well documented in public, peer-reviewed data.

Why predictions are uncertain

Reviews of EV degradation models stress that a model is only as reliable as the data it is fitted to. With little public long-term data on LMFP in vehicles, any model has to lean on assumptions borrowed from LFP and from general lithium-ion behaviour.

Limited public long-term automotive ageing data
Composition varies between suppliers
Blended cathodes make direct comparison with LFP difficult

How Voltgevity treats LMFP

Voltgevity marks its LMFP model as experimental. It starts from LFP-based parameters, adjusts them cautiously and shows a wider uncertainty range than for established chemistries. As more data becomes available these assumptions may change, and the predictions with them.

Key takeaways

LMFP adds manganese to LFP for higher voltage and energy density.
Its ageing is likely related to that of LFP, but public automotive data is limited.
Voltgevity's LMFP model is experimental and uses wider uncertainty ranges.
For now, treat any lifetime claim for LMFP with extra caution.