Recovery of Cobalt and Manganese from Spent Lithium-ion Batteries using a Phosphonium-based Ionic Liquid

Abstract

A novel ionic liquid (IL) trioctyldodecyl phosphonium bis (2,4,4-trimethylpentyl)phosphinate was developed as a recovery agent for cobalt(II) and manganese(II) from spent lithium-ion batteries (LIBs).Absence of organic diluent provides an advantageous factor to IL-based extraction than the conventional one. Co(II) and Mn(II) were extracted quantitatively from the aqueous phase to the IL phase. Extracted Co(II) and Mn(II) were stripped from the IL using water and NH 4 NO 3 , respectively. After stripping, the IL can be reused as the extractant, facilitating the realization of a continuous extraction process. The developed hydrophobic IL shows promise as an extractant for Co(II) and Mn(II) from the spent LIBs. IntroductionLithium-ion batteries (LIBs) have become crucial components of many modern technologies. LIBs are attractive for power storage because of their high charge density, which allows them to be more compact than other rechargeable batteries [1]. The increased use of various types of portable equipment, such as mobile devices and personal computers, in recent decades, has led to huge growth in their market and greatly stimulated the production of LIBs. However, the great increase of LIB usage will be followed by the problem of spent LIBs in forthcoming years [2]. The cathodes of LIBs contain various valuable metals, such as lithium (Li), cobalt (Co), nickel (Ni), and manganese (Mn). Therefore, recycling spent LIBs is considered beneficial from both economic and environmental aspects. To date, the approaches used to recycle valuable metals in LIBs mainly involve pyrometallurgical and hydrometallurgical processes [3].Liquid-liquid extraction is an important hydrometallurgical method in metal processing. For spent LIBs, liquid-liquid extraction is generally carried out using an inorganic acid, such as H 2 SO 4 , HCl, or HNO 3 , as an acidic leaching agent [4].

Removal of Hexavalent Chromium using a PVDF-based Polymer Inclusion Membrane with a phosphonium-based ionic liquid

“…The P8,8,8,12Cl compound was analyzed using 13 C and 31 P NMR spectroscopy as shown in Figure 1A and B. The 31 P NMR spectra in Figure 1A showed a single peak at 34.20 ppm, indicating no oxidation was present in the synthesis process [9]. The chemical composition of P8,8,8,12Cl was found to be consistent with the calculated values (C, 12.10; H, 65.14, N, 0.00) and the experimental results (C, 12.05; H, 66.91; N, 0.02).…”