Recovery of LiCoO2 from Wasted Lithium Ion Batteries by using Mineral Processing Technology

Abstract

Lithium cobalt oxide from a wasted lithium ion secondary battery (LIB) is recovered by means of flotation. At first, the wasted LIB was crushed by vertical cutting mill and classified by air table and vibration screen. Referring to the crushing and separating results, wasted LIB is represented by light materials (organic separator of anode and cathode of battery), metallic materials (aluminum & copper foil, aluminum case etc.) and electrode materials (mixture of lithium cobalt oxide (LiCoO2) and graphite). Electrode materials were thermally treated in a muffle furnace at 773K, followed by flotation to separate LiCoO2 and graphite. The fact that the surface of particles was changed from hydrophobic to hydrophilic due to the removal of binder from the surface at 773K. Considering the results, 92% LiCoO2 was recovered from electrode materials, whereas the purity was higher than 93%. The optimum conditions of flotation process were as follows: 0.2 kg/t kerosene as a collector, 0.14 kg/t MIBC as a frother and 10% pulp density. The experimental results suggested that this process by using mineral processing technology, such as crushing, screening, flotation, etc., is feasible to recover LiCoO2 from the wasted LIB representing a new recycling technique.

Lithium Batteries Recycling

“…Kim et al 30 applied flotation and thermal pretreatment in their process. The black mass was thermally pretreated at 500 C to change hydrophobic properties of particles to hydrophilic.…”

Improving Separation Efficiency in End-of-Life Lithium-Ion Batteries Flotation Using Attrition Pre-Treatment

“…Previous studies have recommended the use of froth flotation, which can be applied to the fine fraction of the black mass (<100 µm) to separate the graphite particles from the lithium metal oxides (LMOs) into two valuable products, increasing the overall efficiency of LIB recycling [14][15][16]. It has even been claimed that after separation through mechanical means, the LMOs [17,18] and graphite particles [19,20] can be applied for battery remanufacturing.…”

“…Froth flotation, a separation process based on surface wettability, is one of the most common processes currently used for primary resource beneficiation [21,22], however, it is still an emerging technique for black mass beneficiation. The concept of froth flotation as a separation technique for active cell components was introduced as early as 2003 based on the assumption of the contrasting surface wettabilities of graphite and LMOs [14]. Many studies have emphasized that the presence of an organic binder coating the active components complicates the separation process and remains among the biggest challenges in black mass flotation [14,23].…”

“…The concept of froth flotation as a separation technique for active cell components was introduced as early as 2003 based on the assumption of the contrasting surface wettabilities of graphite and LMOs [14]. Many studies have emphasized that the presence of an organic binder coating the active components complicates the separation process and remains among the biggest challenges in black mass flotation [14,23]. Consequently, various pre-treatment strategies have been studied to remove the coated binder before flotation.…”

“…In another study, a Fenton reagent pre-treatment proved to be effective in removing the binder, but led to the formation of hydrophobic Fenton secondary products on the surfaces of the LMOs, resulting in the separation of LMOs with a high grade [25,26]. Other researchers have claimed that the application of pyrolysis between 400 • C and 600 • C decomposes the binder and improves the flotation efficiency [14,15,[27][28][29]. For instance, Zhang et al [29] applied mechanical crushing followed by a pyrolysis stage at 500 • C with a heating rate of 10 • C/min and pyrolysis time of 15 min, finally floating the fine fraction of the pyrolyzed product.…”