Expandable Fast Li‐Ion Diffusion Network of Li‐Rich Mn‐Based Oxides via Single‐Layer LiCo(Ni)O 2 Segregation

Abstract Li‐rich Mn‐based cathode materials exhibit a remarkable reversible specific capacity exceeding 250 mAh g −1 , positioning them as the preferred choice for the next generation of high‐energy density lithium‐ion battery cathode materials. However, their inferior rate and cycling performance pose significant challenges. In this context, a Li‐rich material incorporating an expanded fast Li‐ion diffusion network has been successfully synthesized. This advancement involves the introduction of a single‐layer of LiCo(Ni)O 2 with high Li‐ion diffusion coefficients into the crystal structure of Li‐rich cathode, thereby enhancing the rate performance, achieving an impressive capacity of 212 mAh g −1 at 5 C. Furthermore, the single‐layer LiCo(Ni)O 2 can effectively isolates Li 2 MnO 3 phase domains, thereby enhancing the structural stability during the anion redox process, consequently extending the electrochemical stability limits. Operating within a voltage range of 2.1–4.6 V, the capacity retention reaches 80% after 400 cycles, with a voltage decay of merely 0.74 mV per cycle. This innovative utilization of an expanded fast Li‐ion diffusion network provides invaluable insights that will guide the development of strategies aimed at unlocking rate capability in layered oxide cathode materials.