Effect of Mg and Zr co-doping on the Co-less Ni-rich cathode materials for advanced lithium-ion batteries

The Co-less Ni-rich (Ni ≥ 90 %) layered cathode materials are attracting attention because of their high specific capacity and relatively low cost. However, its application is hampered by low cycling stability and structural susceptibility to deterioration. To resolve these issues, the Li0.994Mg0.006(Ni0.925Co0.03Mn0.045)0.996Zr0.004O2 (MZ-NCM) cathode material co-doped with magnesium and zirconium ions was synthesized by the solid-phase method through optimization of the formulation. The physicochemical properties of the materials were investigated in detail by XRD, SEM, EDS, XPS and HR-TEM. Compared with the bare NCM, the MZ-NCM exhibits excellent electrochemical performance with capacity retention of 82.03 % after 150 cycles and discharge specific capacity of 171.81 mAh g−1 at rate of 10C. Comparison of dQ/dV, XRD, SEM and HR-TEM of the electrodes after cycling indicated that the Mg2+ and Zr4+ co-doped cathode maintains intact spherical morphology and relatively stable layered structure.