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.

Shang, Huaifang; Zuo, Yuxuan; Shen, Feiran; Song, Jin; Ning, Fanghua; Zhang, Kun; He, Lunhua; Xia, Dingguo · Nano Lett · 2020

basic_science · Level V

Where this comes from

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 Li<sub>0.78</sub>[Li<sub>0.24</sub>Mn<sub>0.76</sub>]O<sub>2</sub> nanowires were synthesized by a solvothermal reaction to produce P2-type Na<sub>5/6</sub>[Li<sub>1/4</sub>Mn<sub>3/4</sub>]O<sub>2</sub> 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<sup>-1</sup> at 0.1 C and 200 mAh g<sup>-1</sup> 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.