Interface Engineering via Constructing Enhanced Ligand Enables Highly Stable Li-Rich Layered Oxide Cathode

High-energy-density and cost-effective lithium-rich oxides (LRO) are considered as the promising cathode materials for the next-generation lithium-ion batteries . Nevertheless, the elevated cut-off voltage and the complex interface interactions have presented significant challenges that can lead to material degradation. Specifically, the inevitable release of lattice oxygen and the highly reactive interface-driven irreversible migration of transition metal (TM) ions in LRO make the construction of a robust interface extremely important. Herein, an effective and efficient coating approach is applied to stabilize the interface structure of LRO by introducing a coordination bond between the strong ligand of polyurethane (PU) and the surface of LRO particles. This functional coating stabilizes the crystal field stabilization energies of LRO by acting as a strong ligand in spectrochemistry to form a coordination bond with Mn4+ in Li2MnO3 at high voltage. Consequently, irreversible oxygen release and TM ions migration are greatly inhibited. Overall, the LRO-PU cathode exhibits superior electrochemical cyclability with a retention of 80.0% at 1C after 300 cycles and enhanced rate capability with a retention of 80.9% at 0.1C after rate cycles, marking a significant step toward commercial implementation. This study introduces a novel functional polyurethane (PU) coating applied to lithium-rich oxide (LRO) particle surfaces, aiming to enhance their electrochemical performance. The PU coating effectively stabilizes the LRO's crystal field energy through coordination bonds with Mn4+. This leads to a marked reduction in irreversible oxygen release and Mn migration, thus significantly improving the cyclic stability of the electrode material. image