Integrated Oxygen-Constraining\nStrategy for Ni-Rich\nLayered Oxide Cathodes

Surface engineering is sought to stabilize nickel-rich\nlayered\noxide cathodes in high-energy-density lithium-ion batteries, which\nsuffer from severe surface oxygen loss and rapid structure degradation,\nespecially during deep delithiation at high voltages or high temperatures.\nHere, we propose a well-designed oxygen-constraining strategy to address\nthe crisis of oxygen evolution. By integrating a La, Fe gradient diffusion\nlayer and a LaFeO<sub>3</sub> coating into the Ni-rich layered particles,\nalong with incorporating an antioxidant binder into the electrodes,\nthree progressive lines of defense are constructed: immobilizing the\nlattice oxygen at the subsurface, blocking the released oxygen at\nthe interface, and capturing the residual singlet oxygen on the external\nsurface. As a result, effective surface passivation, mitigated bulk\nand surface degradation, suppressed side reactions, and enhanced electrochemical\nperformance are achieved, far beyond conventional single surface modification.\nThe Ni-rich layered oxide cathodes with integrated oxygen-constraining\nmodifications demonstrate impressive cycling stability in both half-cells\nand full cells, achieving stable long-term cycling even at a high\ncutoff voltage of 4.7 V and a high temperature of 45 °C. This\nwork provides a multilevel oxygen-constraining strategy, which can\nbe extended to various layered oxide cathodes involving oxygen release\nchallenges, providing an effective path for the development of high-energy-density\nlithium-ion batteries.