X.X. Ren, G.R. Wang *, T.L. Chen, M.Z. Yang, T. Mu, L. Song, X. Feng * and Z.-S. Wu *

Advanced Functional Materials, 2025, 2422482.

DOI: 10.1002/adfm.202422482 [PDF]

Cobalt-free lithium-rich oxides (LROs) are promising cathode candidates for high-energy-density lithium-ion batteries due to their high specific capacity and cost effectiveness, however, still limited by their structural instability and irreversible oxygen-anionic redox reactions (OARR). Herein, we report a surface-bulk integrated strategy, using trace Ti doping into the bulk and perovskite LaTiO3 coating on the surface of cobalt-free LRO (LP-LRO), to exceptionally strengthen the reversibility of OARR. Profited from the electron-localization effect of Ti doping and the physical-barrier effect of LaTiO3 coating, our LP-LRO achieves an upgraded discharge capacity of 271 mAh g-1 over bare LRO (B-LRO, 243 mAh g-1) at 0.1 C, along with excellent cyclability, maintaining 80% capacity after ultra-long 700 cycles at 5 C, superior to B-LRO (60%) and most reported cobalt-free LROs. Our pouch cell of Si/C||LP-LRO with a capacity of 800 mAh also displays excellent cyclability and energy retention rate, demonstrative of applicability. Using in-situ and ex-situ characterizations, we disclose that the boosted reversibility of OARR and enhanced stability of surface-interface structure are established in LP-LRO, guiding the formation of robust and conductive cathode electrolyte interphases, resulting in greatly improved Li+ storage performance. This work presents an avenue towards high-energy-density cobalt-free LROs for fast-charging long-life batteries.