Upcycling Spent LiNi<sub>0.55</sub>Co<sub>0.15</sub>Mn<sub>0.3</sub>O<sub>2</sub> Battery Cathode via High-Valence-Element Oxide Surface Engineering
Wenyu Wang, Renming Zhan, Yuanjian Li, Zihe Chen, Ruikang Feng, Yuchen Tan, Xiangrui Duan, Jiao Wang, Yong‐Jie Lu, Yongming Sun
Abstract
The advancement of efficient cathode upcycling solutions of degraded batteries is paramount in light of environmental and resource considerations. Here, we introduce a one-step solid-state annealing approach employing nanosized MoO 3 as a surface treatment reagent and LiOH as a lithium compensation reagent to rejuvenate degraded single-crystal LiNi 0.55 Co 0.15 Mn 0.3 O 2 cathodes from 110 Ah electric vehicle batteries. High-valence Mo species enrich along grain boundaries on the material surface, engendering a 5 nm thick amorphous Li–Mo–O interface layer that envelops the revitalized cathode particles with the recovered bulk structure, significantly bolstering ionic conductivity and resistance to undesired side reactions. As a result, the regenerated LiNi 0.55 Co 0.15 Mn 0.30 O 2 achieves a reversible capacity of 184.2 mAh g –1 at 0.1 C and retains 81% of its capacity after 450 cycles at 0.5 C, which outperforms current commercial material. A 120 mAh pouch cell with such a cathode maintains an impressive capacity retention rate of 80.6% even after 700 cycles at 1 C /0.2 C (charge/discharge).