Vanadium-doped lithium-rich layered-structured cathode material Li 1.2 Ni 0.2 Mn 0.6 O 2 with a high specific capacity and improved rate performance

• Published in: RSC advances 2016, Vol.6 (36), p.30194-30198
• Main Authors: Zang, Yong, Sun, Xin, Tang, Zhong-Feng, Xiang, Hong-Fa, Chen, Chun-Hua
• Format: Article
• Language: English
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/C6RA02472F

Fine powders of Li 1.2 Ni 0.2 Mn 0.6−x V x O 2 ( x = 0, 0.002, 0.005, 0.01, 0.02) are prepared by a thermopolymerization method. X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and electrochemical measurements are carried out to characterize these samples. The V-doped samples show great improvement in rate performance and cycling stability, as well as mitigation of voltage decline during cycling. For the optimal composition Li 1.2 Ni 0.2 Mn 0.59 V 0.01 O 2 , it exhibits a discharge capacity of 245 and 118 mA h g −1 at 0.1C and 10C rates, respectively. It retains a capacity of 234 mA h g −1 at 0.1C after 188 cycles with a capacity retention of 95.5%. This study suggests that the partial substitution of Mn 4+ with V 5+ can improve both the rate capability and cycle stability of this high-capacity cathode material.