A High‐Voltage and High‐Capacity Li1+xNi0.5Mn1.5O4 Cathode Material: From Synthesis to Full Lithium‐Ion Cells

We report Co-free, Li-rich Li1+x Ni0.5 Mn1.5 O4 (0<x<1) compounds as high-voltage and high-capacity cathode materials for Li-ion cells. Their tailored morphology allows high density and facile processability for electrode development. In the potential range 2.4-4.9 V, the cathode material of composition Li1.5 Ni0.5 Mn1.5 O4 shows excellent performance in terms of capacity and cycling stability in half-cells. In addition, for the first time, we demonstrate the application of the high-voltage and high-capacity cathode in full Li-ion cells with graphite anodes with very high cycling stability. The electrochemical performance and low cost of the cathode material, together with the feasibility of a chemical method to obtain Li-rich Li1+x Ni0.5 Mn1.5 O4 (0<x<1), make practical applications of high-energy density Li-ion batteries possible.