The quality and yield of batteries are highly dependent on the purity of the materials used. Even trace impurities such as Copper (Cu), Nickel (Ni), Cobalt (Co), and Manganese (Mn) can lead to serious safety, quality, and yield issues. Per Kae E. Fink & Bryant J. Polzin, et al in Influence of metallic contaminants on the electrochemical and thermal behavior of Li-ion electrodes from the Journal of Power Sources, “At the anode, metallic contaminants are found to disrupt performance through direct reaction with Li and may serve as weak catalysts to accelerate electrolyte degradation. At the cathode, metallic contaminants show evidence of crossover during formation cycling to disrupt SEI formation.” That’s why it’s critical to remove these impurities from EV battery recycle streams before they are used for pCAM in battery production.
However, there is a “dirty secret” in Lithium battery recycling that the industry must face. Traditional methods of impurity removal such as Ion Exchange and Solvent Extraction fail to achieve the necessary purity levels for pCAM specification. At lab and pilot scales, these methods may work, but when scaled up to pilot and production levels, they fail to work efficiently.
What about sulfide precipitation chemistry used to remove trace metals? While sulfide precipitation has shown some success in removing trace metals, it is non-specific and produces a terrible odor requiring strict atmospheric control. Additionally, the process is rigid, meaning changes in the stream quality leads to process upsets. From an effectiveness standpoint, A.E. Lewis’ Hydrometallurgy 104 (2010) 222–234 cited that “The copper in solution was not removed to the expected levels, despite excess sulfide being available, despite instantaneous reaction kinetics for the initial precipitation reaction, and despite low CuS solubility over the entire pH range.” This study was conducted in controlled lab working environments, and we all know if it doesn’t work in a lab, it isn’t working in a manufacturing environment.
As stated in the earlier referenced article from Fink & Polzin, it is imperative to remove Cu & Mn metal contaminants from the EV battery recycle streams to prevent anode degradation and cathode cross-over issues leading to premature failure or worse. Enter ElectraMet. Our innovative trace impurity removal from lithium and metal streams is effective and operates at lab, pilot, and production scale. ElectraMet’s chemical-free process selectively removes targeted contaminants using controlled voltage differential and material science. The process stream is purified to meet battery-grade specification while ElectraMet turns the trace metal impurities into high value/purity metal sheets, powders, or salts
Don’t let impurities hold back the quality and yield of your materials. Shine a light into your operation with trace metals removal from your EV battery recycling streams using ElectraMet’s innovative, chemical-free, and cost-effective trace metal impurity removal solutions.
Contact us today to learn more.