Nanostructured high‐energy x Li 2 MnO 3 ·(1‐ x )LiNi 0.5 Mn 0.5 O 2 (0.3 ≤ x ≤ 0.6) cathode materials

Nanostructured lithium‐manganese‐rich nickel‐manganese‐oxide x Li 2 MnO 3 ·(1‐ x )LiNi 0.5 Mn 0.5 O 2 (0.3 ≤  x  ≤ 0.6) composite materials were synthesized via spray pyrolysis using mixed nitrate precursors. All the materials showed a composite structure consisting of Li 2 MnO 3 ( C 2 /m ) and LiNi 0.5 Mn 0.5 O 2 ( R 3 ¯ m ) components, and the amount of Li 2 MnO 3 ‐phase appeared to increase with x, as observed from XRD analysis. These composite materials showed a high‐discharge capacity of about 250 mAhg −1 . In the range of x considered, the layered 0.5Li 2 MnO 3 ·0.5LiNi 0.5 Mn 0.5 O 2 materials displayed the highest capacity and superior cycle stability. Nonetheless, voltage suppression from a layered‐spinel phase transition was observed for all the composites produced. This voltage suppression was dependent of the amount of Li 2 MnO 3 phase present in the composite structure. © 2013 American Institute of Chemical Engineers AIChE J 60: 443–450, 2014