Application of a Flow-Type Electrochemical Lithium Recovery System with λ-MnO₂/LiMn₂O₄: Experiment and Simulation

Abstract

Due to the rapid growth of the global electric vehicle and electronics markets, lithium has become an indispensable resource for our lifestyle, and numerous methods for securing lithium are being actively attempted. For fast and environment-friendly lithium extraction, the electrochemical lithium recovery (ELR) system was studied in recent years. However, there are a limited number of studies regarding the system behavior and most of them are focused on a batch operation, which is far from practical usage. In this study, a flow-type rocking-chair ELR system based on the λ-MnO2/LiMn2O4 electrode pair is proposed for efficient recovery of lithium ions from influents. A lab-scale electrochemical experiment and a two-dimensional numerical simulation are performed to comprehensively analyze the system behavior. It is confirmed that lithium can be simultaneously captured and released at each electrode without any extra electrode regeneration steps. Apart from identifying its behavior experimentally, the spatiotemporal concentration distribution of Li+ in the separator channel is analyzed through numerical simulation. In our system, Li+ is found to be successfully recovered from the source with an energy consumption of 0.56 Wh mol–1 at 6.25 × 10–2 mA cm–2.

Direct Lithium Recovery from Aqueous Electrolytes with Electrochemical Ion Pumping and Lithium Intercalation

“… 5 , 7 , 21 The symmetric rocking-chair battery-like mechanism was introduced by Zongwei Zhao 22 with LiFePO 4 /FePO 4 , further applied to LiMn 2 O 4 /Li 1– x Mn 2 O 4 , 21 and tested in flow-through 23 and flow-by reactors. 24 , 25 …”

“…The ion exchange configuration can be accomplished by a pair of symmetrical Li + intercalation electrodes such as LiFePO 4 or LiMn 2 O 4 with different degrees of lithium intercalation (see Figure ), separated by an anion exchange membrane in contact with natural brine and recovery electrolyte, respectively. ,, The symmetric rocking-chair battery-like mechanism was introduced by Zongwei Zhao with LiFePO 4 /FePO 4 , further applied to LiMn 2 O 4 /Li 1– x Mn 2 O 4 , and tested in flow-through and flow-by reactors. , …”

“…Electrochemical reactors for the extraction of lithium have been described in recent years, both in flow-through ,− and flow-by , configurations (see Figure ). Experiments with a flow-through electrochemical reactor with a symmetric two Li 1– x Mn 2 O 4 (0≤ x ≤ 1) /LiMn 2 O 4 electrodes and anion exchange membrane have been described for the capture and release of lithium from brine into recovery electrolyte .…”

“…5,7,21 The symmetric rocking-chair battery-like mechanism was introduced by Zongwei Zhao 22 with LiFePO 4 /FePO 4 , further applied to LiMn 2 O 4 / Li 1−x Mn 2 O 4 , 21 and tested in flow-through 23 and flow-by reactors. 24,25 This configuration includes an anion selective membrane that separates both source and recovery solutions. When the source of lithium is natural brine with very high salt concentration, i.e., >5 M, Donnan breakdown occurs and the membrane is no longer highly selective.…”

Selective Lithium Adsorption of Silicon Oxide Coated Lithium Aluminum Layered Double Hydroxide Nanocrystals and Their Regeneration

“…We previously reported growth of Li x Al 2 -LDH (0 < x � 1) on an aluminum metal substrate, indicating that adsorbed lithium quantity is strongly correlated with concentrations of LiCl and urea, making it possible to desorb lithium using only water [20] instead of lithium sorbents such as H 2 TiO 3 [21][22] and MnO 2 . [23][24] Herein, recovery of lithium in various mixed anion solutions was studied, where the anions of SO 4 2À , Cl À , NO 3 À , and CO 3 2À were applied to produce the Li x Al 2 -LDH nanostructure layers, which in turn determined the adsorption quantity of lithium. To improve the adsorption and recycling capability for lithium, we studied the effect of retarder additives as well as core-shell coating of the Li x Al 2 -LDH surface to maintain structural stability during repeated cycles.…”