Targeted Surface Doping with Reversible Local Environment Improves Oxygen Stability at the Electrochemical Interfaces of Nickel-Rich Cathode Materials

Citations Over TimeTop 10% of 2019 papers

Abstract

Elemental doping represents a prominent strategy to improve interfacial chemistry in battery materials. Manipulating the dopant spatial distribution and understanding the dynamic evolution of the dopants at the atomic scale can inform better design of the doping chemistry for batteries. In this work, we create a targeted hierarchical distribution of Ti4+, a popular doping element for oxide cathode materials, in LiNi_0.8Mn_0.1Co_0.1O₂ primary particles. We apply multiscale synchrotron/electron spectroscopy and imaging techniques as well as theoretical calculations to investigate the dynamic evolution of the doping chemical environment. The Ti4+ dopant is fully incorporated into the TMO₆ octahedral coordination and is targeted to be enriched at the surface. Ti4+ in the TMO₆ octahedral coordination increases the TM-O bond length and reduces the covalency between (Ni, Mn, Co) and O. The excellent reversibility of Ti4+ chemical environment gives rise to superior oxygen reversibility at the cathode-electrolyte interphase and in the bulk particles, leading to improved stability in capacity, energy, and voltage. Our work directly probes the chemical environment of doping elements and helps rationalize the doping strategy for high-voltage layered cathodes.

Related Papers

• → Doping process of p-type GaN nanowires: A first principle study(2017)29 cited
• → First-principles calculations on structural, electronic properties of V-doped 2H-NbSe2(2014)20 cited
• → Fourier transform infrared study of electrochemically prepared polythienylene films with varying doping levels(1984)60 cited
• → Non-equilibrium Approach to Doping of Wide Bandgap materials by Molecular Beam Epitaxy. Final Report(2004)
• → Modelling the concentration dependence of doping in optical materials(2015)