2022/04/08 by Zhenming Xu, Yongyao Xia, Xu, Zhenming +3
Engineering · Materials Science · #Advancements in Battery Materials #Advanced Battery Materials and Technologies #Supercapacitor Materials and Fabrication
paper · pdf · doi:10.48550/arxiv.2204.03785
Understanding the lattice oxygen dimerization is quite essential for the optimal design for the Li-rich Mn-based cathode materials. In this work, based on the density functional theory (DFT) calculations, a Ni-honeycomb Li-Ni-Mn cation configuration for Li1.22Ni0.22Mn0.56O2 cathode was carefully proposed and examined, which can coexist with the well-known Li-honeycomb structure in the experimentally synthesized Li1.2Ni0.2Mn0.6O2 samples. Li-Ni-Mn cation configurations have significant impacts on oxygen redox activities and oxygen dimerizations in the delithiated LixNi0.22Mn0.56O2. There is no necessary consistency between the high lattice oxygen redox activity and easy oxygen dimerization, such as the Li-honeycomb structures showing higher redox activities and higher activation energy barriers to prohibit oxygen dimerizations than Ni-honeycomb structures. Avoiding the Ni-honeycomb structures with more favorable lattice oxygen dimerization and making full use of the Li-honeycomb structures with better redox activities is important to optimally design the high-performance Li-rich Mn-based cathode materials.