Effect of Dopants on the Functional Properties of Lithium-Rich Cathode Materials for Lithium-Ion Batteries

Multifunctional Ho2O3 Coating with Oxygen Vacancies Enables High-Performance Lithium-Rich Layered Oxide Cathodes

“…The full XPS spectra are presented in Figure S4. As can be seen in Figure a–c, the characteristic peak positions of Ni, Co, and Mn (854.9, 780.1, and 642.3 eV) remain almost unchanged before and after modification . The peak of Ho 4d at 169.5 eV in Figure d belongs to Ho 3+ .…”

Interpretable Machine Learning To Accelerate the Analysis of Doping Effect on Li/Ni Exchange in Ni-Rich Layered Oxide Cathodes

“…Doping with ions such as Na + , Ca 2+ , and Mg 2+ results in the expansion of the Li layer spacing, which suppresses Li/Ni exchange. − Conversely, doping with Ti 4+ and W 6+ promotes the generation of Ni 2+ due to the charge balance mechanism; thereby, it reduces the difference of ionic radius between the TM ions and the Li ions, resulting in an increase in the Li/Ni exchange. − Doping with Al 3+ can inhibit the migration of Ni ions by diminishing the formation of oxygen vacancies, because of the stronger bonding strength of Al–O . Similarly, Zr 4+ and Mg 2+ doping can also hinder the migration of Ni ions from the TM layer into the Li layer, , reducing the Li/Ni exchange in the sample. In terms of electronic structure, the Co 3+ and Al 3+ doping blocks the 180° Ni 2+ –O–Ni 2+ structure with strong superexchange interaction, effectively inhibiting Li/Ni exchange .…”

“…24−27 Doping with Al 3+ can inhibit the migration of Ni ions by diminishing the formation of oxygen vacancies, because of the stronger bonding strength of Al−O. 28 Similarly, Zr 4+ and Mg 2+ doping can also hinder the migration of Ni ions from the TM layer into the Li layer, 28,29 reducing the Li/Ni exchange in the sample. In terms of electronic structure, the Co 3+ and Al 3+ doping blocks the 180°Ni 2+ −O− Ni 2+ structure with strong superexchange interaction, effectively inhibiting Li/Ni exchange.…”

“…When selecting dopant elements, it is imperative to consider their impact on regulating the migration of Ni ions, as well as the disparities in ionic radius between Li ions and the dopant ions . Doping with ions such as Na + , Ca 2+ , and Mg 2+ results in the expansion of the Li layer spacing, which suppresses Li/Ni exchange. − Conversely, doping with Ti 4+ and W 6+ promotes the generation of Ni 2+ due to the charge balance mechanism; thereby, it reduces the difference of ionic radius between the TM ions and the Li ions, resulting in an increase in the Li/Ni exchange. − Doping with Al 3+ can inhibit the migration of Ni ions by diminishing the formation of oxygen vacancies, because of the stronger bonding strength of Al–O . Similarly, Zr 4+ and Mg 2+ doping can also hinder the migration of Ni ions from the TM layer into the Li layer, , reducing the Li/Ni exchange in the sample.…”