Scalable direct recycling of spent LiNi1/3Co1/3Mn1/3O2 via in-situ elements replenishment and structural restoration

Abstract

The proliferation of vehicles and portable devices has led to a significant increase in the number of spent lithium-ion batteries (LIBs). Recycling these spent LIBs is crucial to prevent negative environmental impacts and resource wastage. However, traditional pyrometallurgical and hydrometallurgical methods suffer from inherent drawbacks as being time-consuming, energy-intensive and causing secondary pollution. Herein, an innovative approach is proposed to direct regenerate degraded LiNi1/3Co1/3Mn1/3O2 (NCM111) in-situ by combining hydrothermal treatment with solid-state sintering. Structural and morphology characterizations reveal that the amorphous layer near the surface of degraded NCM111 (D-NCM111) are dissolved after the hydrothermal treatment, restoring the original layered structure due to the relithiation reaction, whereas the target stoichiometric ratios of transition metal elements are achieved through the solid-state sintering process. The regenerated NCM111 (R-NCM111) exhibits a high discharge specific capacity of 152.3 mAh/g at 0.1 C and a capacity retention of 96.1% at 1 C after 300 cycles. The recycling method presented in this work is not only facile but also scalable, potentially opening a new pathway to address the environmental challenges posed by massive spent LIBs.