Grain-boundary engineering of Ni-rich cathodes prolongs the cycle life of Li-ion batteries

Ni-rich layered cathodes (NCM) are appealing for advanced Li-ion batteries thanks to their high-energy density and tolerable cost. Nevertheless, the unfavorable mechanical disintegration coupled with the parasitic reactions greatly deteriorates the electrochemical performance of nickel-rich cathodes, particularly under elevated temperature operation. Herein, a simultaneously Sb-doped and LiSbO3-coated Ni-rich cathode is synthesized through an in situ co-precipitation strategy. The elongated primary particles with radial arrangement could restrain the formation and propagation of microcracks, enhancing the structural stability. Meanwhile, the ion-conductive LiSbO3 coating on primary particles endows the cathode with a robust interface that significantly inhibits secondary particle pulverization and electrolyte erosion. Consequently, the optimal cathode LiNi0.82Co0.11Mn0.06Sb0.01O2 (NCM-1.0%Sb) exhibits a high specific capacity of 199.6 mA h g(-1) at 0.1C and 134.0 mA h g(-1) at 10C. Notably, it displays superior cycling stability with 89.3% capacity retention after 500 cycles at 1C and 55 degrees C in a pouch cell. This work sheds new light on relieving the anisotropic strain of Ni-rich cathodes for long-life lithium-ion batteries.

Automated summary

In this study, a Ni-rich cathode material simultaneously doped with antimony (Sb) and coated with LiSbO3 was synthesized. The resulting cathode showed enhanced structural stability, inhibited microcrack formation and propagation, and effectively suppressed secondary particle pulverization and electrolyte erosion. As a result, the optimized cathode exhibited high specific capacity and excellent cycling stability.