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Preparation of Li Mn Ni1−O2 as a cathode for lithium-ion batteries

1998; Elsevier BV; Volume: 74; Issue: 1 Linguagem: Inglês

10.1016/s0378-7753(98)00011-1

1873-2755

Masaki Yoshio, Yanko Todorov, Kohji Yamato, Hideyuki Noguchi, Jun‐ichi Itoh, Masaki Okada, T. Mouri,

Advanced Battery Technologies Research

The preparation of LiyMnxNi1−xO2 from LiOH·H2O, Ni(OH)2 and γ-MnOOH under oxygen and flowing air is studied. Single phases of LiyMnxNi1−xO2 (0<x<0.3 in O2, 0<x<0.2 in air) are prepared by using γ-MnOOH as a manganese source. The optimum heating temperatures are 800°C for x=0.1 and 850°C for x=0.2. The particle size of the source manganese compound is an important factor for the preparation of the single phase LiyMnxNi1−xO2. It is found that LiyMnxNi1−xO2 is formed from LiyNiO2 and Li2MnO3 at a temperature higher than 750°C. As the average valence of transition metals (Mn and Ni) for LiyMnxNi1−xO2 obtained under flowing oxygen is found to be more than 3, it is experimentally confirmed that manganese in LiyMnxNi1−xO2 exists as both Mn(III) and Mn(IV). For this reason, the presence of LiyMnxNi1−xO2 would be allowed for a wide range of y, for example, 0.99<y<1.10 for LiyMn0.1Ni0.9O2.