Structure and Electrochemical Performance of LiNi0.8Co0.15Al0.05O2 Cathodes Before and After Treatment with Co3(PO4)2 or AlPO4 by in situ Chemical Method
Co3(PO4)2 or AlPO4 coating layers were formed on the surface of LiNi0.8Co0.15Al0.05O2cathode material by in situ chemical method and calcination at 700°C to improve the electrochemical cyclability and structural stability during charge-discharge process of the cathode. The structure and electrochemical properties of the pristine LiNi0.8Co0.15Al0.05O2 cathode materials and the metal phosphate coated-cathode materials were investigated by X-ray powder diffraction, scanning electron microscopy, particle size analysis, Brunauer-Emmett-Teller method, cyclic voltammetry, and galvanostatic charge-discharge test. Co3(PO4)2-LiNi0.8Co0.15Al0.05O2 and AlPO4- LiNi0.8Co0.15Al0.05O2 cathode showed the improved reversibility compared with the pristine cathode material. It is attributed to the structural stability of metal phosphate coated LiNi0.8Co0.15Al0.05O2. In particular, Co3(PO4)2-LiNi0.8Co0.15Al0.05O2 showed a more stable rate capability than the pristine LiNi0.8Co0.15Al0.05O2 and AlPO4-LiNi0.8Co0.15Al0.05O2 at high C-rate.
Surface coating, Cathode, Electrode, Electrochemical properties, Lithium ion batteries
This work was supported by Priority Research Centers Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (20090093818) from the World Class University (WCU) program (R332008-000-10003).
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