Investigation of HEV Li-ion Batteries for Lithium Recovery

Licentiatavhandling, 2012

Automobile electrification is one of the technological developments that may establish an eco-friendly transport system by mitigating vehicle emissions, and hopefully lead to a less fossil fuel-dependent society. Conservative forecasts predict four million electric cars on the road by 2015 (Bernhart et al., 2012). A crucial component of electric vehicles is the battery. This component affects two key performance factors, energy storage and usage. This implies that battery performance is the basis for public acceptance of electric vehicles. The lithium-ion (Li-ion) battery chemistries are the most popular battery chemistries to fulfill this requirement (especially for the complete electric vehicles) among manufacturers. The large influx of HEVs and EVs will present unique challenges for the safe disposal and recycling of their batteries at the end of product life. The high energy density, ironically the characteristic that makes the Li-ion batteries ideal for electric drive, is the cause for concern in handling and processing them at their end of life. However, recycling end-of-life batteries for their constituent metals has multifold advantages. If successful, recycling may effectively mitigate environmental effects of mining/ brine extractions for virgin metals and raw material transportation emissions. In addition, it can also balance fluctuating cost dynamics and ensure a steady supply of raw material. Leaching and separation of the metals in the leachates are two of the main steps in a hydrometallurgy process. Mastering these two steps will allow for the possibility to develop a successful process for the recovery of metals e.g., Li, Cu, Al, Ni, and Mn. In this work, characterizing of the electrochemically active material on the electrodes in relation to their chemical composition and physical phases using XRD, SEM coupled with EDX was done. Leaching study showed that the state of battery charge or microstructure did not affect lechability of metals from the electrodes. Preliminary solvent extraction experiments using the extractants (Cyanex 272, Cyanex 923 and HDBM) resulted in successful separation of Li from other metal ions from chloride solutions.