Tailored Ta ₂ O ₅ /TiO ₂ Nanointerfaces Engineering for Reinforced Structural Integrity and High‐Voltage Performance of Single‐Crystal Ni‐Rich Cathodes

Abstract

Abstract Single‐crystal Ni‐rich ternary materials possess great potential as cathode materials for lithium‐ion batteries (LIBs) due to their high discharge specific capacity and excellent cycling performance. However, their practical utilization is hindered by irreversible phase transitions during cycling, sluggish Li + diffusion, escape of lattice oxygen, and the interfacial side reactions. To address these obstacles, an engineered advanced single‐crystal LiNi 0.8 Co 0.1 Mn 0.1 O 2 (SC‐NCM) is reported by adopting a surface modification strategy using Ta 2 O 5 and TiO 2 to mitigate surface degradation. Experimental results demonstrate that the dual modification effectively stabilizes lattice oxygen, significantly suppresses Li + /Ni 2+ cation mixing, and improves Li + diffusion kinetics. Under a 2.8–4.3 V voltage for 200 cycles at 1 C, the dual‐modified material demonstrates a capacity retention rate of 91.1%, distinctively outperforming the pristine SC‐NCM (54.9%). Moreover, even at harsh cycling conditions with a 4.5 V cut‐off voltage, the designed material retains 64.2% of its capacity, nearly double that of pristine SC‐NCM after 200 cycles. Furthermore, the TaTi‐NCM || graphite pouch cell achieves a capacity retention of 90.3%, significantly surpassing the 81.7% retention observed in the pristine SC‐NCM counterpart after 1000 cycles. This work guides the design of high‐performance single‐crystal Ni‐rich cathode materials through a synergistic modification strategy.