Multifunctional Surface-Integrated Structures Enabling Layered Oxide Cathodes with Stable High-Voltage Cycling
Jie Li, Yujuan Zhang, Xin Dong Guo, Lisi Lu, Xinping Chen, Zelin Li, Yao Luo, Xiaokang Hu, Wenting Li, Hao Liu, Huinan Si, Guixiao Jia, Xinping Qiu
Abstract
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 Li 1.2 Ni 0.2 Mn 0.6 O 2 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 LiCoO 2, highlighting its broad practicality. This work provides new methodologies for advancing the development of high-voltage cathodes.