Y. Zhang, X.Y. Shi, S.H. Zheng, Y.G. Ouyang, M.R. Li, C.X. Meng, Y. Yu*, Z.-S. Wu*

Energy & Environmental Science, 2023, 16.

DOI: 10.1039/D3EE01318A [PDF]

Li-rich oxides (LROs) working on a synergy of cation and anion redox can deliver a greater energy density than commercial cathode materials. However, the lattice strain and structure collapse caused by lithium-ion (de)intercalation ceaselessly accumulate during the cycling, especially at high voltage region, will generate fast performance decay. Herein, we constructed a layered-spinel alternate heterostructure to effectively alleviate the structure evolution of LROs caused by lattice strain with the aid of anchoring effect from spinel phase, and combine with Al2O3 surface coating to prevent transition metal dissolution of LROs. As a result, the optimized Li-rich materials achieved comprehensive properties of an initial Coulombic efficiency of ~100%, high first-cycle specific discharge capacity of 307 mAh/g, and significantly improved cycle stability with 84% capacity retention after 200 cycles, which outperform most previous LROs. Therefore, this synergistic strategy of alternate heterostructure and surface coating provides a new sight to solve the electrochemical decay caused by lattice strain for commercial application of LROs.