A new solid-state process for synthesis of LiMn1.5Ni0.5O4-δ spinel

A new two-step solid-state process was developed for synthesis of a pure phase 4.7V LiMn1.5Ni0.5O4-delta (LMNO) spinel of good electrochemical properties. This process which was based on formation of stable Ni1-xMn2O4-delta (x < 0.33) spinel followed by subsequent lithiation, demonstrated the emerging of LiMn1.5Ni0.5O4-delta frame work at temperatures of as low as 350 degrees C. During this lithiation process, migration of metal ions (Ni/Mn) from partially occupied tetrahedral 8a sites (in Ni0.67Mn2O4-delta) toward octahedral 16d site occurred. The resultant spinel material displayed low irreversible loss, a 97% columbic efficiency and 6% loss in discharge capacity after 100 cycles at 60 degrees C. (C) 2010 Elsevier B.V. All rights reserved.