A High‐Voltage and High‐Capacity Li(1+x)Ni(0.5)Mn(1.5)O(4) Cathode Material: From Synthesis to Full Lithium‐Ion Cells

We report Co‐free, Li‐rich Li(1+x)Ni(0.5)Mn(1.5)O(4) (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 Li(1.5)Ni(0.5)Mn(1.5)O(4) 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 Li(1+x)Ni(0.5)Mn(1.5)O(4) (0<x<1), make practical applications of high‐energy density Li‐ion batteries possible.