Hyperfine fields at the Li site in LiFePO(4)-type olivine materials for lithium rechargeable batteries: a (7)Li MAS NMR and SQUID study.
The (7)Li NMR isotropic shift for olivine LiMPO(4) (M = Fe, Mn, Co, Ni) is assigned to hyperfine coupling between the (7)Li 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.
Tucker
Michael C
MC
Environmental Energy Technologies Division, Materials Sciences Division, Ernest Orlando Lawrence Berkeley National Laboratory and Department of Chemical Engineering, University of California at Berkeley, California 94720, USA.
Doeff
Marca M
MM
Richardson
Thomas J
TJ
Fiñones
Rita
R
Cairns
Elton J
EJ
Reimer
Jeffrey A
JA