Dependence of electrochemical properties of spinel LiMn2O4 on Li2CO3 with micro-flaky, micro-flower and nanorod morphologies

Abstract

Herein, the dependence of spinel LiMn₂O₄ on Li₂CO₃ with micro-flaky, micro-flower and nanorod morphologies is investigated. The results show that the as-synthesized LiMn₂O₄ with micron sized Li₂CO₃ as raw materials have a much higher discharge capacity than that of the one prepared with nano sized Li₂CO₃. It delivers an initial charge capacity of 110.1, 105.2 and 104.9 mA h g⁻¹ followed by a discharge capacity of 109.1, 103.9 and 104.2 mA h g⁻¹ with the micro-flower, nanorod and micro-flaky Li₂CO₃ morphologies, respectively, at room temperature (about 99% of the charge capacity is discharged). The smaller specific surface area is found in the spinel LiMn₂O₄ with micron sized Li₂CO₃, resulting in a better stable electrochemical performance in LiMn₂O₄ with micro-flower and micro-flaky Li₂CO₃. Their capacities are maintained at 99.2 mA h g⁻¹ and 94.2 mA h g⁻¹ after 100 cycles at 1C rate. The capacity retention was more than 90% at the 100^th cycle with the micron-sized Li₂CO₃. Moreover, the as-synthesized spinel LiMn₂O₄ with micro-flower Li₂CO₃ retained more than 95% of its initial discharge capacity (92 mA h g⁻¹) after 200 cycles at 2C rate. The cubic spinel structure was detected after 200 cycles of LiMn₂O₄ at 2C rate.