Effect of the impurity LixNi1−xO on the electrochemical properties of 5 V cathode material LiNi0.5Mn1.5O4

The formation of impurity LixNi1−xO when synthesizing spinel LiNi0.5Mn1.5O4 using solid state reaction method, and its influence on the electrochemical properties of product LiNi0.5Mn1.5O4 were studied. The secondary phase LixNi1−xO emerges at high temperature due to oxygen deficiency for LiNi0.5Mn1.5O4 and partial reduction of Mn4+ to Mn3+ in LiNi0.5Mn1.5O4. Annealing process can diminish oxygen deficiency and inhibit impurity LixNi1−xO. The impurity reduces the specific capacity of product, but it does not have obvious negative effect on cycle performance of product. The capacity of LiNi0.5Mn1.5O4 that contains LixNi1−xO can deliver about 120 mAh g−1.

► This manuscript investigated the influence of impurity LixNi1−xO on the electrochemical properties of LiNi0.5Mn1.5O4.
► The impurity LixNi1−xO is usually present in products synthesized by solid state methods which are used in industry.
► So this study is useful to produce LiNi0.5Mn1.5O4 commercially.