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

• Published in: Ionics Vol. 18; no. 1-2; pp. 19 - 25
• Main Authors: Yo, Chul-Hyun, Ju, Jeong-Hun, Kim, Gyeong-Ok, Hwang, Moon-Jin, Ryu, Kwang Sun
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 2012
• Subjects: Chemistry; Chemistry and Materials Science; Condensed Matter Physics; Electrochemistry; Energy Storage; Optical and Electronic Materials; Original Paper; Renewable and Green Energy; Lithium secondary battery; Cathode; ); Co; Nano-coating; Electrochemical property; C-rate; PO
• ISSN: 0947-7047; 1862-0760
• DOI: 10.1007/s11581-011-0591-x

Li[Co 0.1 Ni 0.15 Li 0.2 Mn 0.55 ]O 2 was synthesized, as a cathode material with high capacity, by a simple combustion method followed by annealing at 800 °C. Li[Co 0.1 Ni 0.15 Li 0.2 Mn 0.55 ]O 2 cathode materials were coated with lithium-active Co 3 (PO 4 ) 2 to improve the electrochemical performance of rechargeable lithium batteries. Morphologies and physical properties of Li[Co 0.1 Ni 0.15 Li 0.2 Mn 0.55 ]O 2 before and after the Co 3 (PO 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[Co 0.1 Ni 0.15 Li 0.2 Mn 0.55 ]O 2 cathode material before and after Co 3 (PO 4 ) 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 (PO 4 ) 2 coating was investigated at 0, 10, 20, 30, 40, and 50 °C at a rate of 0.1 C. Co 3 (PO 4 ) 2 -Li[Co 0.1 Ni 0.15 Li 0.2 Mn 0.55 ]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 (PO 4 ) 2 -coating layer on Li[Co 0.1 Ni 0.15 Li 0.2 Mn 0.55 ]O 2 .