Achieving dynamic stability of single-crystal low-Co Ni-rich cathode material for high performance lithium batteries

Abstract

The demand for high-energy-density lithium-ion batteries (LIBs) has driven intensive research into cathode materials that exhibit both superior performance and stability over multiple charge–discharge cycles. This work focuses on enhancing the dynamic stability of single-crystal (SC) low-cobalt (Co) nickel-rich (Ni-rich) cathode materials, crucial for the advancement of LIB technology. The proposed strategy involves co-doping of iron (Fe) and aluminum (Al) with an optimized composition to mitigate the capacity degradation and voltage fading observed for traditional Ni-rich (≥90%) cathodes. Through a comprehensive investigation combining theoretical modeling, material synthesis, and electrochemical characterization, the synergistic effects of Fe/Al co-doping are elucidated. The presence of Fe and Al ions in the crystal lattice not only stabilizes the structural integrity but also facilitates the suppression of phase transformation and surface degradation during cycling. Moreover, the incorporation of Fe and Al ions optimizes the lithium (Li)-ion diffusion kinetics and enhances the electronic conductivity, leading to improved electrochemical performance. The achieved dynamic stability of the co-doped SC cathode material enables prolonged cycle life and high-rate capability, making it a promising candidate for next-generation LIBs.