One‐Step Activation of Anode Materials from Spent Lithium‐Ion Batteries as High‐Performance Electrodes for Capacitive Deionization

Abstract

AbstractMesophase microporous carbon spheres (MMCS), are the anode materials of spent lithium‐ion batteries (LIB), existing in large amounts on the earth that result in resource wastes and ecological pollution. In order to utilize the above waste resources, a new idea of recycling scrapped LIB anode materials was exploited to apply for capacitive deionization (CDI). Herein, the activated microporous carbon spheres (AMCS) were synthesized by a one‐step KOH activation of mesophase microporous carbon spheres (MMCS). By controlling the weight ratios of KOH to MMCS, the fabricated AMCS with the optimal specific surface area of 2626 m2 g−1 and the pore volume of 0.98 cm3 g−1 were fabricated. The AMCS3‐1 with a weight ratio of KOH to MMCS of 3 : 1 exhibits higher specific capacitance (196.9 F g−1) and lower charge transfer resistance. Importantly, the AMCS3‐1 electrode demonstrates excellent electrosorption capacity of 12.73 mg g−1 and fast salt adsorption rate of 2.64 mg g−1 min−1 at 1.2 V. In addition, the excellent repeatability over 50 regeneration cycles could be obtained for AMCS3‐1 electrode compared with commercial activated carbon electrode. The results reveal that the AMCS3‐1 is a promising candidate as high‐performance electrodes for CDI. The strategy of recycling MMCS from waste LIB anode materials for CDI is desirable, which displays great potential in the removal of sodium chloride (NaCl).