Slower capacity/voltage degradation of surface engineered LiNi_0.92Co_0.05Mn_0.03O₂ cathode for lithium-ion batteries

Ni-rich layered oxides are considered as a promising commercial cathode material due to high energy density and low cost. However, the severe capacity degradation and poor rate capability caused by structural collapse during long cycles limit their practical application. Herein, a NASICON-structured Li₂AlZr(PO₄)₃ is constructed on the surface of LiNi_0.92Co_0.05Mn_0.03O₂ for stabilizing the layered structure. In addition, the construction process consumes the lithium residues on the surface of the material particles, thus reducing alkalinity of the material surface. Meanwhile, the electrochemical properties of the samples are studied. The capacity of the 1 wt% Li₂AlZr(PO₄)₃ coated sample shows 144.2 mAh g⁻¹ with a discharge middle voltage of 3.71 V after 400 cycles under the voltage range of 2.7–4.3 V. Further studies confirm that the uniform NASICON coating can effectively alleviate the structural degradation and intergranular cracks after long-term cycling. The research results illustrate the feasibility of the practical application of the modification strategy, which can be popularized in Ni-rich layered cathode materials.