Facile synthesis and performances of nanosized Li2TiO3-based shell encapsulated LiMn1/3Ni1/3Co1/3O2 microspheres

Abstract

LiMn_1/3Ni_1/3Co_1/3O₂ microspheres covered by a nanosized Li₂TiO₃-based shell are prepared by a facile synthesis method. First, a controllable TiO₂ nano-layer is grown on the surface of a spherical Mn_1/3Ni_1/3Co_1/3CO₃ precursor, and then the resultant TiO₂@LiMn_1/3Ni_1/3Co_1/3O₂ hybrid is synchronously transformed in situ into a hierarchical Li₂TiO₃@LiMn_1/3Ni_1/3Co_1/3O₂ microsphere through a solid-phase reaction. It has been found that the hierarchical Li₂TiO₃@LiMn_1/3Ni_1/3Co_1/3O₂ microspheres exhibit a good rate capability with a discharge capacity of 92.3 mA h g⁻¹ even at higher rates of 20 C between 3.0 and 4.3 V. Besides, they possess excellent cyclic stability especially at high rates, with a capacity retention of 90.3% after 500 cycles at a 20 C rate. The enhanced electrochemical performance of the hierarchical Li₂TiO₃@LiMn_1/3Ni_1/3Co_1/3O₂ at high rates is attributed to the stable and fast Li⁺-conductor characteristic of the nanosized Li₂TiO₃-based shell. Thus, the Li₂TiO₃@LiMn_1/3Ni_1/3Co_1/3O₂ microspheres will be a promising cathode material for lithium-ion batteries with high power density and excellent cycling performance.