A heterobimetallic single-source precursor enabled layered oxide cathode for sodium-ion batteries

A single-source precursor NaCo(acac)(3) (acac = acetylacetone) for layered oxide cathodes of sodium-ion batteries (SIBs) is reported here. It features a 1D chain structure, and is prepared in nearly quantitative yield employing commercially available reagents. The complex is stable in open air and tends to dissolve in various strongly polar solvents, including H2O and methanol. The phase-pure layered oxide cathode material P2-NaxCoO2 for SIBs is obtained through calcining the complex, and exhibits an excellent rate capability, even superior to the recently reported P2-NaxCoO2 microspheres. More analogue complexes could be obtained through cationic replacement for the synthesis of other high-performance layered metal oxides for SIBs.