Associate professor Xiang Li from the Phase Change Energy Storage Group at the Qinghai Institute of Salt Lakes, Chinese Academy of Sciences, proposed a novel technique for upcycling of low-nickel, heterogeneous ternary cathode mixed scraps (NCM523). This technique has proved successful in transforming NCM523 into nickel-gradient single-crystal NCM811 cathode material, which outperforms the original material.
The study systematically revealed the dynamic reconstruction pathways involved in regenerating mixed ternary cathode scraps. Key findings indicate that particles of different sizes degrade unevenly during air storage, with smaller particles being significantly more vulnerable. This air exposure leads to severe lithium loss from the lattice and transformation into a detrimental rock-salt phase, posing major challenges for direct regeneration. This is overcome through mechanical ball milling combined with homogeneous liquid-phase Li/Ni/Co supplementation. This approach effectively regenerated multisource, size-heterogeneous NCM523 scrap into single-crystal Ni-rich NCM811 cathodes, eliminating the need for stringent conditions or highly uniform feedstock. Upcycled U-NCM811 delivers a highly specific capacity of 202 mAh g−1 at 0.1C, retaining 80.7% capacity after 200 cycles at 1C and 79.4% capacity at 5C, thereby outperforming the capacity of commercial single-crystal NCM811. Furthermore, the regenerated material effectively suppressed the detrimental H₂→H₃ phase transition, significantly enhancing structural stability and battery safety.
This technological breakthrough establishes a novel pathway for recycling cathode materials from massive quantities of obsolete batteries, and converts low-value, heterogeneous scraps into high-value-added, single-crystal nickel-rich cathode materials (NCM811) through waste-to-resource transformation, significantly enhancing the economic value of scrap materials. The strategy liberates the process from dependence on highly uniform raw materials, demonstrating distinct advantages including process simplicity, economic feasibility, and environmental friendliness. It provides crucial technical support and an innovative paradigm for building a sustainable battery circular economy system. These findings were published in Small Methods under the title: "Upcycling Low-Nickel LixNi0.5Co0.2Mn0.3O2 (0<x<1) Scraps toward High-Performance Single-Crystal Ni-rich Cathodes" (DOI: 10.1002/smtd.202501383). This work was funded by the Major Science and Technology Projects of Qinghai Province (2025-QY-230) and Qinghai Provincial Thousand Talents Program for High-level Innovative Professionals.
