O2-Type Li<sub>0.78</sub>[Li<sub>0.24</sub>Mn<sub>0.76</sub>]O<sub>2</sub> Nanowires for High-Performance Lithium-Ion Battery Cathode
Huaifang Shang, Yuxuan Zuo, Feiran Shen, Song Jin, Fanghua Ning, Kun Zhang, Lunhua He, Dingguo Xia
Abstract
Continued improvement in the electrochemical performance of Li–Mn–O oxide cathode materials is key to achieving advanced low-cost Li-ion batteries with high energy densities. In this study, O2-type Li0.78[Li0.24Mn0.76]O2 nanowires were synthesized by a solvothermal reaction to produce P2-type Na5/6[Li1/4Mn3/4]O2 nanowires, which were then subjected to molten salt Li-ion exchange. The resulting nanowires have diameters less than 20 nm and lengths of several micrometers. The full-Mn-based nanowires cathode material delivers a reversible capacity of 275 mAh g–1 at 0.1 C and 200 mAh g–1 at a high current rate of 15 C with a capacity retention of more than 80% and the voltage decay was dramatically suppressed after 100 cycles. This excellent performance is ascribed to the highly stable oxygen redox reaction and lack of layered-to-spinel phase transition in the O2-type structure during cycling.