Redox-active stabilizer-enhanced structural and thermal stability of Ni-rich cathodes via an economical blending strategy

With the increasing demand for high-energy-density lithium-ion batteries, enhancing the structural and thermal stability of nickel-rich cathode materials has become imperative for fulfilling the performance prerequisites for diverse applications. Nevertheless, nickel-rich cathodes frequently experience structural deterioration and thermal instability, particularly during high-voltage cycling. To address these obstacles, we propose an innovative and economically viable blending strategy by incorporating 10 wt% lithium iron phosphate (LiFePO₄, LFP) as a “redox-active stabilizer” into layered NCM811. LFP, characterized by its robust phosphorus-oxygen covalent bonds, augments the structural and thermal stability of NCM811, while preserving high energy density and alleviating mechanical strain during cycling. The NCM-10 %LFP blended cathode exhibited outstanding electrochemical performance, attaining capacity retention of 65.1 % at 0.2C and 71.2 % at 1C after 200 cycles. Furthermore, the thermal stability of the blended cathode is markedly enhanced, with the initiation temperature of thermal runaway postponed. This investigation provides novel perspectives on the interfacial interactions between LFP and NCM811 and presents a scalable, cost-effective solution for the development of high-performance cathode materials with increased safety and durability for advanced lithium-ion batteries.