Porous sphere-like LiNi0.5Mn1.5O4-CeO2 composite with high cycling stability as cathode material for lithium-ion battery

Abstract A new type of microsized porous spherical LiNi 0.5 Mn 1.5 O 4 -CeO 2 cathode material composed of aggregated nanosized particles with P 4 3 32 space groups was prepared by an ethanol-assisted hydrothermal method. The nanosized particle shortens the Li + -ion diffusion path in the bulk LiNi 0.5 Mn 1.5 O 4 and then improves the fast charge–discharge performance of this material. Moreover, a thin CeO 2 layer with nanometer thickness on the surface of the LiNi 0.5 Mn 1.5 O 4 particles is helpful for suppressing the interfacial side reactions. Because of these advantages, the LiNi 0.5 Mn 1.5 O 4 -CeO 2 materials exhibit excellent electrochemical properties. Compared with the pristine LiNi 0.5 Mn 1.5 O 4 , LiNi 0.5 Mn 1.5 O 4 -CeO 2 (3 wt%) exhibits outstanding discharge capacity, cycling stability and rate capability. LiNi 0.5 Mn 1.5 O 4 -CeO 2 (3 wt%) delivers discharge capacities of 129.7, 121.2, 118.1, 109.8, and 86.3 mAh g −1 at 0.2, 0.5, 1, 2, and 5 C discharge rates, but the pristine one only delivers discharge capacities of 119.9, 103.7, 91.8, 84.7 and 34.4 mAh g −1 at the corresponding discharge rates. The introduction of CeO 2 is a valid approach to enhance the electrochemical property of the LiNi 0.5 Mn 1.5 O 4 material by forming an excellent electrical contact between CeO 2 layer and LiNi 0.5 Mn 1.5 O 4 surface, leading to an enhanced lithium-ion diffusion coefficient, reduced electrochemical polarization, and improved conductivity.