Dual-site lattice co-doping strategy regulated crystal-structure and microstructure for enhanced cycling stability of Co-free Ni-rich layered cathode

Abstract

Affected by cobalt (Co) supply bottlenecks and high costs, Co-free Ni-rich layered cathodes are considered the most promising option for economical and sustainable development of lithium-ion batteries (LIBs). Low-cost LiNixAl1−xO2 (x ≥ 0.9) cathode are rarely reported due to their chemo-mechanical instabilities and poor cycle life. Herein, we employ a strategy of Mg/W Li/Ni dual-site co-doping LiNi0.9Al0.1O2 (named as LNA90) cathodes to enhance cycling stability by modifying the crystal structure and forming a center radially aligned microstructure. The Mg/W co-doped LiNi0.9Al0.1O2 cathode (named as LNAMW) exhibits high capacity retention of 94.9% at 1 C and 3.0–4.5 V after 100 cycles with 22.0% increase over the pristine cathode LNA90 and maintains the intact particle morphology. Meanwhile, the cycling performance of LNAMW cathode exceeds that of most reported Ni-rich cathodes (Ni mol% > 80%). Our work offers a straightforward, efficient, and scalable strategy for the future design of Co-free Ni-rich cathodes to facilitate the development of economical lithium-ion batteries.