A Structure Self-Healing Li-Rich Cathode Achieved by Lithium Supplement of Li-Rich LLZO Coating

摘要

Lithium-rich manganese-based cathode materials (LLMO) are consideredas the promising candidates for realizing high energy density lithium-ionbatteries. However, the severe structure deterioration and capacity fadinghinder their large-scale application. Herein, an innovative electrochemicallithium supplement strategy is put forward to inhibit the structure collapseand enhance the cycling stability of Lithium-rich manganese-based cathodes.Besides, combining with the superior Li-ion conductor Li_(6.25)La_3Zr_2Al_(0.25)O_(12)(LLZAO), remarkable rate capability is achieved. As a result, a capacity retentionof 95.7 after 300 cycles at 1.0 C (1.0 C = 200 mA g~(?1)), as well as a stablecycling at 5.0 C with discharge capacity of 136.9 mAh g~(?1), are harvested.Moreover, the excess lithium ions in LLZAO mitigate the spinel-like phasetransformation via inserting into the lithium layer and stabilizing the cathodestructure. In addition, the lithium ions migration behavior in the elaboratedcathode is thoroughly expounded and the correlation between diffusionkinetics and LLZAO is revealed. These findings boost the updating of LLMOand pave a new pathway for stabilizing LLMO structures.