Promoting Durability of Ni-Rich Layered Oxide via Inverse Spinel NiFe₂O₄ Interface Layer for High-Voltage Lithium-Ion Batteries

The interfacial instability of layered Ni-rich cathodes is acknowledged as a significant obstacle to their usefulness in cutting-edge lithium-ion batteries. Surface engineering is a good option to overcome rapid capacity decay and uncontrolled thermal runaway. Herein, an inverse spinel NiFe 2 O 4 (NFO) interface layer is built on Ni-rich LiNi 0.8 Co 0.1 Mn 0.1 O 2 materials by a simple wet chemical strategy. It is discovered that fast ion transport kinetics between particles are guaranteed by the NFO coating with good lithium-ion conductivity. Additionally, the NFO layer is characterized by high toughness and can accommodate stress changes, which can prevent an irreversible phase transformation. It also functions as a physicochemical barrier to suppress interfacial side reactions and the dissolution of transition-metal ions. The optimized Ni-rich cathode, profiting from the advantages of the lithium-ion-conductive NiFe 2 O 4 coating layer, demonstrates improved high-voltage prolonged cycling durability, superior rate capability of 112.7 mA h g –1 at 10C, and high-temperature stability of 130 mA h g –1 after 100 cycles at 60 °C. Our strategy herein provides an alternative route for tuning the surface structural features of the Ni-rich cathodes for advanced lithium-ion storage applications.