Multiscale Construction of Integrated Lithium ion Transport Channels for High-Rate Ni-Rich Cathode Materials in Lithium ion Batteries

Ni-rich layered oxide cathodes have garnered significant attention in the field of lithium ion batteries (LIBs) due to their exceptionally high energy density. Nevertheless, their performance in terms of rapid charging/discharging and cycle life remains suboptimal. In this study, an integrated, multi-scale optimization of Li⁺ transport kinetics from the interface to the near-surface layer of Ni-rich cathode materials is achieved through a synergistic optimization strategy of constructing a highly conductive interface layer and a lattice channel optimization layer. Experimental findings show that a Li₃PO₄/Li₄P₂O₇ composite ion transport layer with high ionic conductivity is in situ constructed on the cathode surface, which not only improved the Li⁺ migration kinetics but also suppressed the unfavorable side reactions at the electrode/electrolyte interface. The incorporation of P-Al co-doping in the near-surface layer significantly reduced the intrinsic diffusion energy barrier of lithium ions and effectively alleviated the lattice volume change and the degradation of the surface lattice structure during the cycling process. Consequently, the modified cathode material exhibits excellent rate performance (154 mAh g⁻¹ at 10C) and cycle stability (89.6% capacity retention after 200 cycles). This work demonstrates that the synergistic optimization of multiscale lithium ion transport channels is a viable approach for achieving high-performance Ni-rich cathodes.