From waste graphite to high-value carbon materials: Direct recycling and nanotechnology-enabled upcycling of lithium-ion aattery anodes
Abstract
The direct recycling of graphite, the anode material in lithium-ion batteries, is comprehensively examined in this study. The research integrates mineral processing techniques with a nanostructural regeneration approach. Graphite is a vital component of modern battery technologies due to its high electrical conductivity, chemical stability, and capacity for lithium intercalation. However, traditional pyrometallurgical and hydrometallurgical recycling methods primarily focus on recovering valuable metals, while degrading the graphite structure, which subsequently requires energy-intensive synthesis processes for reuse. The direct recycling approach aims to restore the performance of electrode materials by preserving their crystal structure and morphology. While graphite could recover from black mass with over 90% efficiency via flotation following mechanical pre-treatment, preserving its structural integrity, the process remains inherently complex due to surface impurities, heterogeneous phase composition, limitations in particle liberation and selectivity, and the requirement for precise reagent optimization. Furthermore, the study evaluates relithiation methods for cathodes and purification techniques for graphite anodes, including thermal, chemical, electrochemical, and hybrid approaches. The findings indicate that direct recycling significantly reduces energy consumption and lowers global warming potential by 70–96%, while generating high economic added value. In conclusion, the direct recycling approach offers a strong alternative for sustainable battery technologies from environmental, economic and technological perspectives.