Improving the single crystal LiNi0.8Co0.1Mn0.1O2 cathode material performance by fluorine doping

Abstract

With the rapid popularization of new energy vehicles, the demands for high energy density power batteries and related cathode materials are becoming increasingly urgent. Layered Li–Ni–Co–Mn–O cathode materials are attracting much attention because of their high specific capacity; however, their cycling and high voltage performance need to be further improved. Herein, single crystal structure LiNi0.8Co0.1Mn0.1O2 materials, prepared using a multiple-step calcination process, are further controllably doped with fluorine to improve the Li storage performance. Fluorine doping not only improves the crystal space but also increases the Co3+ and lattice oxygen content, therefore promoting the lithium ion diffusion and crystal structure stability of layered LiNi0.8Co0.1Mn0.1O2. With an appropriate amount of fluorine doping, the LiNi0.8Co0.1Mn0.1O2 single crystal material demonstrates a remarkable specific capacity of 202.7 mAh g−1 (0.1C) and a high capacity retention of 86.6% after 100 cycles (1.0C), higher than the control sample and promising for application in lithium-ion batteries.