Zirconium effect on the lithiation mechanism of LiNi0.83Mn0.05Co0.12O2 positive electrode material

Ni-rich LiNi1-x-yMnxCoyO2 (x + y ≤ 0.2) materials are employed to enhance the energy density of lithium-ion batteries, while they are still facing the stability issue. Doping is considered as an efficient approach to improve the stability of the LiNi1-x-yMnxCoyO2 materials. A considerable number of studies have concluded that Zr-doping improves the stability when undoped and doped LiNi1-x-yMnxCoyO2 materials are lithiated under the same conditions. Unfortunately, a fundamental understanding of the Zr dopants role during lithiation conditions is still lacking. This work investigates the Zr effects on lithiation mechanism of LiNi0.83Mn0.05Co0.12O2 (NMC). The main findings are: First, the NMC and Zr-doped NMC have different lattice parameter growth speeds, and the (003) & (101) lattice planes form order structures at lower temperatures during lithiation process when the dopant is included. Second, Zr is prone to locate near the surface region of NMC secondary particles. Third, when lithiation time increases from 8 h to 12 h at 800 °C, the undoped NMC electrochemical performance deteriorates whereas the doped material improves. These findings highlight that understanding the mechanism behind lithiation conditions is essential for doped LiNi1-x-yMnxCoyO2. The insights revealed in this work can guide for design of other dopants for Ni-rich positive electrode materials. [Display omitted] •LiNi0.83Mn0.05Co0.12O2 (NMC) phase evolution is affected by Zr-doping.•Zr is suggest affecting lithium diffusion during the lithiation.•Zr doped and the undoped material have different optimal synthesis conditions.•Zr prone to located near the surface area and produce rock salt phase.•Lithiation condition and Zr-doping affect the functionality of NMC.