Direct Conversion of Waste Battery Cathodes to High‐Volumetric‐Capacity Anodes with Assembled Secondary‐Particle Morphology

Abstract

AbstractThe growing consumption of lithium‐ion batteries calls for recycling of electrode materials. Conventional direct recycling mainly consists of cathode‐to‐cathode and anode‐to‐anode strategies. In this work, a cathode‐to‐anode approach is proposed using a LiCoO2 model system and extending to Co‐lean/Co‐free cathodes (LiNi0.8Co0.1Mn0.1O2, LiMn2O4, and LiFePO4). Commercial cathodes are featured with single‐crystalline or secondary‐particle polycrystalline morphology, thus exhibiting higher tap density than anodes (LiCoO2 2.7 g cm−3 vs Si 0.25 g cm−3). By means of an intuitively direct conversion, the anodes are bestowed with well‐assembled morphology and high tap density from cathodes. During discharging, a dual conductive network is formed to facilitate lithium storage, where the binder‐derived carbon functions as electronic‐conductive and LiF/Li2O as ionic‐conductive motifs. Recycled cathodes exhibit an outstanding rate volumetric capacity (883 mAh cm−3, 5 A g−1, LiCoO2) and cyclic performance (1286 mAh cm−3, 1000 cycles, 2 A g−1, LiMn2O4). The morphologically inherited cathode‐to‐anode strategy proves to be a universal method for battery recycling toward high volumetric energy density.