Study on oxygen deficiency in spinel LiNi0.5Mn1.5O4 and its Fe and Cr-doped compounds

The oxygen deficiency is an important factor to affect the electrochemical properties of spinel LiNi0.5Mn1.5O4. In this study, we investigated how oxygen deficiency in spinel LiNi0.5Mn1.5O4 was affected by calcination temperature and oxygen partial pressure. The oxygen deficiency as a function of calcination temperatures has been modeled. Doping elements have influence on oxygen deficiency. The oxygen dissipation of Cr-doped compounds LiNi0.45Cr0.1Mn1.45O4 at high temperature is less than pristine LiNi0.5Mn1.5O4. Under the same calcination and cooling condition, there more oxygen deficiency remained in Fe and Cr-doped compounds than in pristine LiMn1.5Ni0.5O4. The coulomb efficiencies of LiNi0.45Cr0.1Mn1.45O4 in the first charge and discharge cycle reached a high value of 89.1%.