Chemical and process mineralogical characterizations of spent lithium-ion batteries: An approach by multi-analytical techniques

• Crushed products can be divided into three parts based on the main composition.
• A certain kind of hydrocarbon is found coated on the surface of fine particles.
• A flowsheet to recycle spent LiBs is proposed according to multi-analysis results.

Mineral processing operation is a critical step in any recycling process to realize liberation, separation and concentration of the target parts. Developing effective recycling methods to recover all the valuable parts from spent lithium-ion batteries is in great necessity. The aim of this study is to carefully undertake chemical and process mineralogical characterizations of spent lithium-ion batteries by coupling several analytical techniques to provide basic information for the researches on effective mechanical crushing and separation methods in recycling process. The results show that the grade of Co, Cu and Al is fairly high in spent lithium ion batteries and up to 17.62 wt.%, 7.17 wt.% and 21.60 wt.%. Spent lithium-ion batteries have good selective crushing property, the crushed products could be divided into three parts, they are Al-enriched fraction (+2 mm), Cu and Al-enriched fraction (−2 + 0.25 mm) and Co and graphite-enriched fraction (−0.25 mm). The mineral phase and chemical state analysis reveal the electrode materials recovered from −0.25 mm size fraction keep the original crystal forms and chemical states in lithium-ion batteries, but the surface of the powders has been coated by a certain kind of hydrocarbon. Based on these results a flowsheet to recycle spent LiBs is proposed.