A Dual-Functional Synergetic Strategy Enhances the Interfacial and Structural Stability of LiCoO₂ at High Voltage

With the advent of the 5G era, the widespread application of various smart devices and cutting-edge technologies has imposed stringent requirements on the battery lifespan and durability. This study proposes a synergistic modification strategy combining Mg 2+ and Y 3+ dual doping with Li 3 PO 4 coating. Herein, Mg 2+ exhibits a gradient distribution near the surface and a uniform distribution inside, enhancing electronic conductivity while facilitating the penetration of the Y element into the particle interior. What is more, the addition of Y 3+ significantly widens the Li + transmission channels, greatly enhancing the rapid charge–discharge performance. The synergistic interaction of Mg 2+ and Y 3+ stabilizes the internal structure, while the Li 3 PO 4 coating serves to effectively block a direct interaction between the electrolyte and the cathode surface, stabilizing the surface structure and improving the long-term cycling performance. The findings indicate that the synergistic approach adjusts the Co 3d and O 2p energy bands, effectively suppressing the hybridization phenomenon of Co and O orbitals. Remarkably, the proposed strategy maintains a superb capacity retention rate of nearly 80% after 300 cycles at 4.6 V, and it exhibits an excellent reversible capacity of 109.6 mAh·g –1 even at 10 C, thus demonstrating the superior overall performance and vast application potential of this approach.