Lithium separation from heat-treated waste lithium-ion batteries

Abstract

Two types of the waste lithium batteries (Spent-LIBs) without crushing were heated in a batch furnace at 500–550 °C for 5 h, then crushed and the lump metals from outer package removed to obtain the powder sample “Black sand”. The simple substances of Ni, Co, Fe, Al, Cu, and C were mainly contained along with MnO, LiAlO₂, and LiF in the black sand. The carbon used in the anode would act as a reducing agent to obtain the simple substances in the sealed lithium-ion batteries. The minor metals of Li, Ni, Co, and Mn were abundantly contained in the sieved black sand of less than 500 µm size with the carbon. The metals of Al, Cu, and Fe from the package and the current collector of the batteries were contained in the large sieved particles. The average elution ratio for the lithium using deionized water was ca. 69–70 % from the black sand. The elution ratio was higher for the samples having a particle size smaller than 300 µm, and it decreased for the samples having a larger particle size. The formation of the insoluble LiAlO₂ phase in water affected the Li non-dissolution in the black sand. The metals and oxides in the black sand dissolved in a 4 M HCl solution except for the carbon.