Hyperfine fields at the Li site in LiFePO4-type olivine materials for lithium rechargeable batteries:: A 7Li MAS NMR and SQUID study

The 7Li NMR isotropic shift for olivine LiMPO4 (M = Fe, Mn, Co, Ni) is assigned to hyperfine coupling between the 7Li nucleus and the transition metal unpaired electrons on the basis of the Curie-Weiss temperature dependence of the shift. The hyperfine shift arises from a linear combination of Li-O-M through-bond interactions wherein the unpaired A′ electrons contribute a negative shift and the unpaired A″ electrons contribute a positive shift. The hyperfine coupling constant is determined for each composition. Copyright © 2002 American Chemical Society.