Multifunctional Surface-Integrated Structures Enabling Layered Oxide Cathodes with Stable High-Voltage Cycling

Severe surface instability of layered oxide cathodes under high-voltage operation poses a fatal problem that leads to poor cycling stability in high-energy lithium-ion batteries. Herein, we report a reliable and universal solution quenching strategy to fabricate a multifunctional surface-integrated structure, which comprises a dual nanolayer structure design: the outer layer is a disordered rock-salt structure, and the inner layer exhibits a La-doped layered structure. We elucidate that the integrated structure greatly restrains lattice oxygen release and structural degradation and facilitates the formation of thin and robust cathode electrolyte interface (CEI) film. Consequently, the modified Li1.2Ni0.2Mn0.6O2 exhibits stable high-voltage cycling with a capacity retention of 86.9% and a potential decay rate of only 0.68 mV cycle–1 after 500 cycles at 1 C. Importantly, this strategy achieves stable high-voltage cycling of LiCoO2, highlighting its broad practicality. This work provides new methodologies for advancing the development of high-voltage cathodes.