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

•LiNi0.5Mn1.5O4-CeO2 shows an excellent fast charge-discharge performance.•LiNi0.5Mn1.5O4-CeO2 shows excellent cycling stability.•The introduction of CeO2 is conducive to the improvement of the kinetics property.

A new type of microsized porous spherical LiNi0.5Mn1.5O4-CeO2 cathode material composed of aggregated nanosized particles with P4332 space groups was prepared by an ethanol-assisted hydrothermal method. The nanosized particle shortens the Li+-ion diffusion path in the bulk LiNi0.5Mn1.5O4 and then improves the fast charge-discharge performance of this material. Moreover, a thin CeO2 layer with nanometer thickness on the surface of the LiNi0.5Mn1.5O4 particles is helpful for suppressing the interfacial side reactions. Because of these advantages, the LiNi0.5Mn1.5O4-CeO2 materials exhibit excellent electrochemical properties. Compared with the pristine LiNi0.5Mn1.5O4, LiNi0.5Mn1.5O4-CeO2 (3 wt%) exhibits outstanding discharge capacity, cycling stability and rate capability. LiNi0.5Mn1.5O4-CeO2 (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 CeO2 is a valid approach to enhance the electrochemical property of the LiNi0.5Mn1.5O4 material by forming an excellent electrical contact between CeO2 layer and LiNi0.5Mn1.5O4 surface, leading to an enhanced lithium-ion diffusion coefficient, reduced electrochemical polarization, and improved conductivity.

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