Complex gas formation during combined mechanical and thermal treatments of spent lithium-ion-battery cells

Characterization and Thermal Treatment of the Black Mass from Spent Lithium-Ion Batteries

“…These gas species include electrolyte compounds (such as dimethyl carbonate (DMC) and diethyl carbonate (DEC)), oxygenated hydrocarbons (such as CH2O), hydrocarbons (such as CH4 and C6H6), and other miscellaneous gases (such as HBr, C2N2, HCN, and POF3). The similarity of the gas species released from the BM and those released from LIBs cells reported in another study [15] can mainly be attributed to the similarity in organic compounds in the LIBs cells, which are mainly composed of volatile organic compounds (VOCs), conductive LiPF6 salt, organic binder (notably PVDF), and organic separator (such as PP). Even though most of them could have been released or liberated during the mechanical treatment process for producing BM, some of them could still be left and entrapped in the BM, especially when considering the fineness of the achieved BM.…”

“…On the other hand, a home-made reactor consisting of an airtight stainless-steel chamber equipped with online multi-component mass spectrometer (Ion-Molecule Reaction (IMR) mass spectrometer, model Airsense 2000, mass range 7-519 amu), a data acquisition computer, and calibration gases was used for detection of gas release from BM2 under pyrolytic conditions. The experimental setup of the reactor has been described elsewhere [15]. The BM was subjected to comprehensive analysis using qualitative and quantitative analytic tech-niques.…”

“…It is therefore believed that the fumes come from the evaporation and/or decomposition of the leftover electrolyte components and the decomposition of organic binder (such as PVDF) and separator (such as PP). By employing a home-made reactor and following a similar procedure as that reported in a previous study [15], the gas released from the BM samples (500 g in a batch), under three different pyrolytic temperatures, namely 120 °C, 300 °C, and 500 °C, in an N2 atmosphere, were analyzed by a multicomponent mass spectrometer. The observed mass losses were 1.3%, 17.8%, and 26.5% at 120 °C, 300 °C, and 500 °C, respectively.…”

“…A higher concentration of formed gases at higher temperatures can also be correlated to a higher mass loss. The quantitative data of gaseous species that have been detected by mass spectrometry during the thermal heating of black mass were described elsewhere [15]. The formation of gas species necessitates the need for safety countermeasures during the transportation of end-of-life LIBs and using them as feedstock in the pyrometallurgical and/or hydrometallurgical treatment process.…”

Efficient Photo-Oxidation Leaching of Ni and Co in a Spent Lithium-Ion Battery Cathode by Homogeneous UV/H2O2

“…Pyrometallurgy and hydrometallurgy are widely used in industrial areas for large-scale recycling . In particular, hydrometallurgy has shown excellent performance in leaching metals from spent LIBs, with an efficiency of >95% and product purity of >90% . However, such techniques have limitations, such as excessive chemical consumption to complete leaching, involvement of corrosive chemicals, such as strong acids and bases, secondary pollution due to wastewater generation after leaching, and waste gas emission caused by strong corrosive liquid .…”