Electronic structure regulated by precursor gradient design assists inhibition of nanopores for stable Ni-rich cathodes

Abstract

The mechanical integrity of particles plays a key role in the electrochemical performance of Ni-rich cathodes. However, nanopore defects, caused by the non-synchronized thermodynamics and kinetics during the sintering process, destroy the structural integrity. Herein, we report an approach to regulating the electronic structure of the precursor to promote the synchronization of lithiation and decomposition processes during sintering. The findings based on structural characterizations and density functional theory calculations demonstrate that constructing more Ni-O-Mn configurations on the precursor surface via element gradient design can accelerate charge transfer kinetics and reduce Li⁺ insertion energy barrier, ultimately enhancing lithiation kinetics and suppressing nanopore formation. This work presents a new strategy for preserving the mechanical integrity of particles during the high-temperature lithiation of Ni-rich precursors.