A comprehensive study of the role of transition metals in O3-type layered Na[NixCoyMnz]O2 (x = 1/3, 0.5, 0.6, and 0.8) cathodes for sodium-ion batteries

Spherical O3-type layered Na[Ni_xCo_yMn_z]O₂ cathodes were synthesized by co-precipitation. An increase in the Ni concentration results in an increase of specific discharge capacity but the corresponding capacity retention and thermal stability progressively decreased.