Enhancement of the cycling stability of an electrochemical lithium recovery system via state-of-charge (SoC) control

Abstract

Based on the lithium ion selective electrode, electrochemical lithium recovery (ELR) is a promising lithium recovery technology in which lithium ions are adsorbed and desorbed on the electrode. However, the stability of the ELR system is not sufficient for continuous lithium ion recovery. Here, we report a novel approach for improving the stability of the ELR system through the state-of-charge (SoC) control scheme. In this system, the electrode is composed of lithium manganese oxide (LiMn2O4, LMO) and silver (Ag), and lithium ions are captured in the LMO electrode. The stability of the LMO electrode is improved by using 60 % of the maximum capacity via SoC control. After 50 cycles, the 60 % SoC discharge capacity is maintained at 85.4 %, showing better performance compared to the 100 % SoC approach (60.0 % discharge capacity). In addition, the performance of lithium recovery with 60 % SoC control was more energy efficient with similar lithium ion capacity and selectivity compared to the 100 % SoC operation method. These results suggest that the SoC control scheme could be an efficient method to enhance the stability of ELR techniques. © 2023 Elsevier B.V.