Sustainable upcycling of spent LiCoO2 to an ultra-stable battery cathode at high voltage

Recycling forms an essential dimension of batteries' sustainability. Here the authors show a straightforward process that directly upgrades spent LiCoO2 to a Mg and Al co-substituted LiCoO2 cathode with a high voltage of 4.6 V and excellent cycling stability. The continued market growth for electric vehicles globally is accelerating the transformational shift to a low-carbon transportation future. However, the sustainability of this transition hinges to a large extent on the management of waste, including end-of-life batteries where strategic elements such as lithium (Li) and cobalt (Co) are present. Different from the existing pyrometallurgical and hydrometallurgical recycling methods that involve heavy energy inputs and the use of hazardous chemicals, here we show a feasible single-step process that not only reclaims lithium cobalt oxide (LiCoO2) from waste Li-ion batteries but also upgrades it to a cathode with enhanced electrochemical properties. Our recycling process is based on a direct reaction between spent LiCoO2 and added mixture of Al2O3, MgO and Li2CO3, during which the Li vacancies aid the diffusion of Al and Mg to yield dual-doped LiCoO2. The upgraded LiCoO2 cathode possesses even better structural stability and sustains 300 cycles retaining 79.7% of its initial capacity at a voltage of 4.6 V. As evidenced by the technoeconomic analysis, the current circularity approach exhibits cost benefits and could catalyse further progress in the upcycling of different materials for batteries.

Automated summary

The study presents a simple method for upgrading spent LiCoO2 to a high-voltage and cycling-stable cathode through Mg and Al co-substitution. The global growth of the electric vehicle market is accelerating the transition to low-carbon transportation. The sustainable management of waste, including end-of-life batteries containing strategic elements like lithium and cobalt, is crucial for this transition, and this study provides a feasible recycling process for reclaiming and upgrading LiCoO2 from waste lithium-ion batteries.