Nickel-substituted LiMnPO4/C olivine cathode material: Combustion synthesis, characterization and electrochemical performances
By Khalfaouy, Redouan EL; Turan, Servet; Dermenci, Kamil Burak; Savaci, Umut; Addaou, Abdellah; Laajeb, Ali; Lahsini, Ahmed
Published in Ceramics International
2019
Abstract
Transition metals substitution in cathode materials is considered as an effective approach to improve the electrochemical performances of lithium–ion batteries. In this regard, host and Ni-substituted LiMn1-xNixPO4 (x = 0.00–0.05) olivine cathode materials were successfully synthesized by a modified solution combustion method. The structural and morphological properties were examined by X–ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), Transmission electron microscopy (TEM) and Raman spectroscopy. According to X-ray diffraction results, all substituted materials LiMn1-xNixPO4/C adopt an identical structure to that of the LiMnPO4 olivine structure, suggesting that the nickel ion has been well incorporated into the crystal lattice, without any changes in the host material structure. When x = 0.05, the material shows an excellent specific capacity and stability during charge/discharge process. The initial specific discharge capacity can reach up to 138.6 mAh g−1 at C/20 between 2.5 and 5 V, with a coulombic efficiency of about 91.1%. The results confirm that the cyclic stability and the electrochemical performances of LiMnPO4/C were highly improved by Ni-doping.