C-rate and temperature dependence of electrochemical performance of Li[Co0.1Ni0.15Li0.2Mn0.55]O2 cathode materials before and after Co3(PO4)2 coating

Li[Co0.1Ni0.15Li0.2Mn0.55]O-2 was synthesized, as a cathode material with high capacity, by a simple combustion method followed by annealing at 800 degrees C. Li [Co0.1Ni0.15Li0.2Mn0.55]O-2 cathode materials were coated with lithium-active Co-3(PO4)(2) to improve the electrochemical performance of rechargeable lithium batteries. Morphologies and physical properties of Li[Co0.1Ni0.15 Li0.2Mn0.55]O-2 before and after the Co-3(P-4)(2) coating were analyzed with a scanning electron microscope equipped with an energy dispersive X-ray spectroscope. Transmission electron microscopy, powder X-ray diffraction, and Brunauer-Emmett-Teller surface area analyses were also carried out. The electrochemical performances of Li[Co0.1Ni0.15Li0.2Mn0.55]O-2 cathode material before and after Co-3(PO4)(2) coating were evaluated by galvanostatic charge-discharge testing at different charge and discharge densities. The temperature dependence of the cathode material before and after Co-3(PO4)(2) coating was investigated at 0, 10, 20, 30, 40, and 50 degrees C at a rate of 0.1 C. Co-3(PO4)(2)-Li[Co0.1Ni0.15Li0.2Mn0.55]O-2 exhibited good electrochemical performance under high C-rate and experimental temperature conditions. The enhanced electrochemical performances were attributed to the formation of a lithium-active Co-3(PO4)(2)-coating layer on Li[Co0.1Ni0.15Li0.2Mn0.55]O-2.