Synthesis, structure and electrochemistry of LiMn_(2-y)Cr_(y/2)Cu_(y/2)O_4 (0.0 ≤y≤0.5) prepared by wet chemistry

摘要

The LiMn_2O_4 co-doped with copper and chromium forming LiMn_(2-y)Cr_(y/2)Cu_(y/2)O_4 spinel phases have been synthesized by wet chemistry technique using an aqueous solution of metal acetataes and dicarboxylic acid (succinic acid) as a complexing agent. The structural properties of the synthesized products have been investigated by X-ray powder diffraction, Raman scattering, and Fourier-transform infrared spectroscopy. To improve the rechargeable capacity of Li//LiMn_(2-y)Cr_(y/2)O_4 cells, the electrochemical features of LiMn_(2-y)Cr_(y/2)Cu_(y/2)O_4 compounds have been evaluated as positive electrode materials. The structural properties of these oxides are very similar to LiMn_2O_4, their electrochemical performances show that the capacity is maintained 95% of the initial value at the 36th cycle for y=0.1, this being explained by the change of Mn~(3+)/Mn~(4+) ratio in doped phases.