Lithium iron phosphate (olivine) LiFePO₄

Unit cell

Lattice constants

a = 10.332 Å, b = 6.010 Å, c = 4.692 Å; α = 90°, β = 90°, γ = 90°

Cell volume

291.4 ų

Atoms in the cell

28 (Li 4, Fe 4, P 4, O 16)

Formula units Z

4

Calculated density

2.89 g cm⁻³

Shortest contact

1.523 Å

Coordination

Li

CN 6 at 2.09 Å (6 O)

Fe

CN 6 at 2.06 Å (6 O)

P

CN 4 at 1.52 Å (4 O)

O

CN 1 at 1.52 Å (1 P)

About the structure

• Olivine framework: PO₄ tetrahedra and FeO₆ octahedra share corners and edges; Li⁺ sits in octahedral channels running along b (the short axis of this Pnma cell).
• Li⁺ diffusion is one-dimensional along those channels, so particle size and defects matter a lot — this is why commercial LFP is nano-sized and carbon-coated.
• Safe, long-lived, cobalt-free cathode (3.4 V vs Li); the Fe²⁺/Fe³⁺ couple is buffered by the phosphate.
• Coordinates from the Crystallography Open Database, entry 2100916 (open data); hydrogen and water sites with partial occupancy below 0.5 are left out.

Atom positions (fractional, one cell)

Z, coordination numbers, distances, density and packing on this page are computed from these coordinates.