Effect of LiFePO 4 coating on electrochemical performance of LiCoO 2 at high temperature

• Published in: Solid state ionics Vol. 178; no. 1; pp. 131 - 136
• Main Authors: Wang, Hong, Zhang, Wei-De, Zhu, Lun-Yu, Chen, Ming-Cai
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 2007
• Subjects: Coating; Lithium cobalt oxide (LiCoO 2); Lithium iron phosphates; Lithium-ion battery; Lithium-ion battery; Coating; Lithium cobalt oxide (LiCoO 2); Lithium iron phosphates
• ISSN: 0167-2738; 1872-7689
• DOI: 10.1016/j.ssi.2006.10.028

LiFePO 4 coating on LiCoO 2 with a thickness ranging 10–100 nm improved the electrochemical performance of the cathode material at high temperature and high potential. At 60 °C and at a rate of 1 C, 5.0 wt.% LiFePO 4-coated LiCoO 2 showed better capacity retention (132 mAh/g) with 4.2 V charge-cutoff after 250 cycles, while the bare cathode (pure LiCoO 2) showed 5% capacity retention under the same conditions after only 150 cycles. When cycled at 60 and 75 °C, the amount of Co dissolution from LiCoO 2 was greatly reduced in the LiFePO 4-coated cathode material. The coating layer of LiFePO 4 not only protects the LiCoO 2 but also serves as an active cathode material with good conductivity. The LiFePO 4-coated LiCoO 2 could be a high performance cathode material for Li-ion battery.