Volatile Heterometallic Precursors for the Low-Temperature Synthesis of Prospective Sodium Ion Battery Cathode Materials

Heterometallic single-source precursors
with a proper sodium:transition-metal
ratio for nonoxide sodium ion battery cathode materials are reported.
Heterometallic fluorinated β-diketonates NaM­(hfac)3 (M = Mn (1), Fe (2), Co (3), and Ni (4); hfac = hexafluoroacetylacetonate) have
been obtained on a large scale, in high yield using a one-step reaction
that employs commercially available reagents. The complexes are stable
in open air and highly volatile. The mass spectrometric investigation
indicates the existence of heterometallic molecules in the gas phase.
The presence of heterometallic species in solutions of several solvents
has been unambiguously confirmed. Heterometallic precursors were shown
to exhibit clean, low-temperature decomposition in argon atmosphere
that results in phase-pure perovskite fluorides NaMF3,
the prospective cathode materials for sodium ion batteries.