Inhibition of Adverse Phase Transition at 4.2 V via increasing Cobalt Content on Ni-Rich Layered Cathode Materials

作者：Yang, Wei^*; Xie, Qian; Fang, Kaibin; Wang, Chengyun; Zou, Hanbo; Chen, Shengzhou

来源：ACS Applied Energy Materials, 2021, 4(7): 7365-7375.

DOI：10.1021/acsaem.1c01534

• lithium-ion battery
• Ni-rich material
• phase behavior
• doping modification
• cyclic performance
• lattice

Nickel-rich layered materials are the most commercially valuable power battery materials. However, because of the existence of Ni3+, lattice deterioration of nickel-rich ternary materials is especially serious in the cycle process. In this experiment, LiNi0.8-xCo0.1+xMn0.1O2 is prepared by increasing the content of cobalt (x = 0.02, 0.04, 0.06). Through electrochemical test, X-ray diffraction analysis, galvanostatic intermittent titration technique, Rietveld refinement analysis, and other characterization methods, the effect of cobalt content enhancement on the nickel-rich layered materials is explained. With the increase of cobalt content, the adverse phase transition of 4.2 V is inhibited, and the material shows preferable stability during cycling. Incredibly and encouragingly, the samples with increasing cobalt content show superior performance of cycle and rate, less redox inhomogeneity and impedance, and also higher initial Coulomb efficiency. According to these results, the nickel-rich high cobalt layered material LiNi0.82Co0.12Mn0.06O2 was synthesized, which showed excellent performance. This research proves the complex and indispensable role of cobalt and provides a cobalt-rich strategy for the design of nickel-rich layered materials.

• 单位
  广州大学