Exploring separation techniques for the direct recycling of high voltage spinel LNMO scrap electrodes

Abstract

Among various recycling methods, direct recycling has emerged as a promising approach for recovering battery materials and directly reusing them to reduce carbon emissions and enhance the sustainability of the battery production process. Our study unveils, for the first time, different separation techniques for the delamination and the efficient direct recycling of high-voltage spinel LiNi_0.5Mn_1.5O₄ (LNMO) cathode materials from scrap electrodes, evaluating chemical, mechanical, and thermal separation techniques. The impact of the separation technique on the active material and the influence of the particle morphology and binder type (aqueous and organic solvent) on the outcomes of these separation techniques is assessed in terms of recovery yield, purity, and electrochemical performance. The recovered materials' physicochemical properties show minimal alterations after the recycling process. The investigated separation techniques allow the complete delamination of the electrodes and the recovery of around 90% of the active material. The recovered LNMO is used without further treatment for preparing new electrodes, which achieve 95% of the cycling capacity of pristine LNMO after 100 charge/discharge cycles. These lab-scale findings are validated on pre-pilot-line and commercial production-line-processed electrode scraps.