Recovery of lithium hydroxide from discarded lithium-ion batteries

Recovery of lithium (Li) compounds from various Li resources is attracting attention due to the increased demand in Li-ion battery industry. Current work presents an innovative route for selective recovery of lithium content in the form of lithium hydroxide monohydrate (LiOH<middle dot>H2O) from discarded LIBs. Lithium carbonate (Li2CO3) with purity > 99% is recovered from black mass. The recovered Li2CO3 is then crystallised to LiOH<middle dot>H2O by using calcium hydroxide (Ca(OH)(2)) as the base. The method comprises of: (i) pre-treatment of LIB black mass powder; (ii) selective extraction of Li content from black mass; (iii) crystallisation and solid-liquid separation to recover LiOH<middle dot>H2O as final recovered product. A total of 0.1933 wt.% impurities comprising of Ca, Al, Cu and Fe were detected in the recovered product. Elemental analysis at each processing step was carried out using inductively coupled plasma-optical emission spectroscopy. Structural properties of the recovered materials are analysed by using X-ray diffraction, field emission scanning electron microscopy. Fourier-transform infrared spectroscopy spectrum of recovered product was found consistent with the formation of LiOH<middle dot>H2O. The LiOH<middle dot>H2O is successfully recovered from discarded LIBs with purity of 99.8%, which finds its potential use as secondary raw material in battery manufacturing, Li-based high temperature grease manufacturing, carbon dioxide scrubbing in space craft and submarines, etc.