Structural and Electrochemical Aspects of LiNi_0.8Co_0.1Mn_0.1O₂ Cathode Materials Doped by Various Cations

Abstract

Ni-rich materials of layered structure LiNi x Co y Mn z O2, x > 0.5, are promising candidates as cathodes in high-energy-density Li-ion batteries for electric vehicles. The structural and cycling stability of Ni-rich cathodes can be remarkably improved by doping with a small amount of extrinsic multivalent cations. In this study, we examine development of a fast screening methodology for doping LiNi0.8Co0.1Mn0.1O2 with cations Mg2+, Al3+, Si4+, Ti4+, Zr4+, and Ta5+ by a “top-down” approach. The cathode material is coated by a precursor layer that contains the dopant, which then is introduced into the particles by diffusion during heat treatment at elevated temperatures. The methodology described herein can be applied to Ni-rich cathode materials and allows relatively easy and prompt identification of the most promising dopants. Then further optimization work can lead to development of high-capacity stable cathode materials. The present study marks Ta5+ cations as very promising dopants for Ni-rich NCM cathodes.

Soft X-ray Absorption Spectroscopic Investigation of Li(Ni0.8Co0.1Mn0.1)O2 Cathode Materials

“…The transition metal oxide (TM-O) and Li-O bond distances are 1.978 and 2.0978 Å, respectively. These parameters are similar to those reported for this composition of NMC cathode material [25]. In this structure, almost 2.52% of Ni ions occupy the Li-ions site ( Table 1).…”

“…The transition metal oxide (TM-O) and Li-O bond distances are 1.978 and 2.0978 Å, respectively. These parameters are similar to those reported for this composition of NMC cathode material [25]. Nanomaterials 2020, 10, x FOR PEER REVIEW 2 of 11 phenomena due to the orbital symmetry states in the oxide cathode material during charging and discharging.…”

Low‐Temperature Charging and Aging Mechanisms of Si/C Composite Anodes in Li‐Ion Batteries: An Operando Neutron Scattering Study

“…During electrochemical operation, the diffraction angle of the NCA reflex changed owing to the oxygen repulsion, which is typical for layered oxides . However, in the break after charging, neither its intensity nor its position changed (see Supporting Information, Figures S2 and S3).…”

Ambient‐Pressure Relithiation of Degraded LixNi0.5Co0.2Mn0.3O2 (0 < x < 1) via Eutectic Solutions for Direct Regeneration of Lithium‐Ion Battery Cathodes

“…The degraded particles showed a larger intensity ratio of I 003 /I 104 compared with the pristine sample, which is consistent with some previous report. [38] The reason for this phenomenon might be related to the preferred orientation of certain facets after microstructure changes during cycling. [32] Additionally, Weigel et al also showed that some of the cycled NCM811 cathode samples also had higher I 003 /I 104 ratio and lower cation mixing.…”

“…[32] Additionally, Weigel et al also showed that some of the cycled NCM811 cathode samples also had higher I 003 /I 104 ratio and lower cation mixing. [38] The reason for this phenomenon might be related to the preferred orientation of certain facets after microstructure changes during cycling. [39,40] The (003) peak shifted to lower angles, corresponding to an increase in c lattice parameter due to the electrostatic repulsion between the oxygen layers along c directions in the Li-deficient state.…”