Improvement of the electrochemical properties of a LiNi0.5Mn1.5O4 cathode material formed by a new solid-state synthesis method

In order to avoid the shortcomings of large particle size and poor uniformity of material synthesized by the traditional solid-state method, this paper utilizes a simple improvement of calcination process (i.e., calcination–milling–recalcination) based on the traditional solid-state synthesis to successfully prepare a large number of well-distributed, micrometer-sized, spherical secondary LiNi_0.5Mn_1.5O₄ particles. Each particle is composed of nano- and/or sub-micrometer-sized grains. Results of the electrochemical performance tests show that the material exhibits a remarkable cycle performance and rate capability compared with that obtained from traditional synthesis method; the spherical LiNi_0.5Mn_1.5O₄ particles can deliver a large capacity of 135.8 mAh g^?1 at a 1 C discharge rate with a high retention of 77 % after 741 cycles and a good capacity of 105.9 mAh g^?1 at 10 C. Cyclic voltammetry measurements confirm that the significantly improved electrochemical properties are due to enhanced electronic conductivity and lithium-ion diffusion coefficient resulting from the optimized morphology and particle size. This improved method is more suitable for mass production.