LIBs that have reached the end of life and are sent for recycling, may still hold some residual energy and that is dangerous during handling and processing. The high voltage and reactive components of end-of-life LIBs pose safety hazards during mechanical processing and crushing stages, as well as during storage and transportation. Electrochemical discharge method provides an efficient, quick, and inexpensive way to eliminate such hazards. For the first time, in this study we have demonstrated an entirely new approach of the utilization of an Fe(II)-Fe(III) redox couple electrolyte to electrochemically discharge LIBs below safe voltage level (below 0 % State of charge SOC) [1]. We have revealed that redox medium can be used for efficient LIB deep discharge to a voltage of 2.0 V after rebound, a level that is low enough for safe discharge. In addition, no corrosion on the battery casing was observed. We have observed that battery which contains high Ni-content stainless steels are more suited for an electrochemical discharge in aqueous environment. Finally, it was discovered that battery casing material plays a vital role in electrochemical discharge, and its industrial standardization would facilitate efficient recycling.

Reference:

(1). Enhanced electrochemical discharge of Li-ion batteries for safe recycling N. Garg, S. Pekkinen, E-M.Gonzalez, R.S.Guerrero, P. Peljo and A.S. Aarnio, (Sustainable Energy & Fuels (2024), 8, 2777–2788