Shang Huaifang, Zuo Yuxuan, Shen Feiran, Song Jin, Ning Fanghua, Zhang Kun, He Lunhua, Xia Dingguo
Key Lab of Theory and Technology for Advanced Battery Materials, College of Engineering, Peking University, Beijing 100871, P.R. China.
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, P.R. China.
Nano Lett. 2020 Aug 12;20(8):5779-5785. doi: 10.1021/acs.nanolett.0c01640. Epub 2020 Jul 15.
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[LiMn]O nanowires were synthesized by a solvothermal reaction to produce P2-type Na[LiMn]O 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 at 0.1 C and 200 mAh g 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.
锂锰氧化物正极材料的电化学性能持续改善是实现先进低成本、高能量密度锂离子电池的关键。在本研究中，通过溶剂热反应合成了O2型Li[LiMn]O纳米线，以制备P2型Na[LiMn]O纳米线，然后对其进行熔盐锂离子交换。所得纳米线直径小于20nm，长度为几微米。全锰基纳米线正极材料在0.1C时的可逆容量为275mAh/g，在15C的高电流速率下为200mAh/g，容量保持率超过80%，并且在100次循环后电压衰减得到显著抑制。这种优异的性能归因于高度稳定的氧氧化还原反应以及循环过程中O2型结构中缺乏层状到尖晶石的相变。
