Aluminum and Indium Co‐Modified Ni‐Rich Layered Cathode with Enhanced Microstructure and Surface Stability for Lithium‐Ion Batteries

Abstract

AbstractNi‐rich layered oxides are considered as promising cathodes for next‐generation lithium‐ion batteries. However, they still suffer microstructure and surface instability particularly under high operating voltage, leading to rapid capacity fading and battery failure. In this context, Ni‐rich layered cathodes (LiNixCoyMn1−x−yO2; LNCM) with aluminum and indium co‐modified crystal and surface structures are developed by a simple one‐pot calcination approach. Battery tests show that the Al and In co‐modified LNCM electrodes demonstrate remarkably enhanced rate capability and cycling stability compared with the pristine LNCM, Al‐doped LNCM, and In‐modified LNCM counterparts. Further characterizations reveal a simultaneous suppression of cracking and resistive film growth. The improved microstructural and surface stability originate from the synergistic functions of Al and In co‐modification. The incorporation of Al3+ into transition metal slab significantly reduces the Li+/Ni2+ antisite, which noticeably mitigates the undesired layer to rock‐salt phase transformation. The In3+ dopant dispersed in Li interslab can dissipate the anisotropic lattice strain, enabling greatly improved reversibility of H2↔H3 phase transition occurred in delithiation‐lithiation processes. Meanwhile, the synchronously formed LiInO2 adherent coatings deplete lithium residues, facilitate lithium‐ion transfer, and resist electrolyte corrosion. Microstructure and surface engineering through Al and In co‐modification offer a promising design strategy for Ni‐rich layered cathodes.