Fig. 2: Migration evolution of surface morphology and elemental distribution during galvanic leaching process.
From: Galvanic leaching recycling of spent lithium-ion batteries via low entropy-increasing strategy
SEM image of NCM particles with galvanic leaching times of a 0 min, b 5 min, c 10 min, d 20 min, e 30 min and f 40 min. g-i are the micro-morphology of particles from the surface to the bulk of NCM electrode strips at a galvanic-leaching time of 5 min, along with the corresponding elemental distribution of cobalt and fluorine, while j–l and m–o represent the situations at leaching times of 10 min and 40 min, respectively. g–i, j–l, and m–o are samples from three parallel experiments, all conducted under the leaching condition of 2 mol/L HCl, 200:1 mL/g and 60 °C. g–o The leached positive electrode strip is placed in a mold with an upright straightener, and then cured with poured epoxy resin to form a hard resin block, and finally is sandblasted and polished to reveal its cross-section.
