Aqueous lithium–ion batteries have made considerable progress since Dahn first proposed water–based lithium–ion batteries in 1994 , , . The aqueous lithium–ion battery combines two lithium insertion materials, and the electrolyte uses a neutral lithium salt solution.
Electrochemical lithium ion pumps (ELIP) technology attracts considerable attention for their environmental friendliness, high efficiency, and device simplicity. In this review, we summarize and present advances in lithium extraction by ELIP from aqueous resources containing lithium.
Guo et al. also used an LMO/Li1-xMn2O4rocking-chair battery system for electrochemical lithium extraction and optimized the selectivity of lithium recovery using a constant current-constant voltage electric field drive.
In order to improve the lithium–ion extraction performance of the ion exchange battery system, Kim et al. modified the carbon–coated LiFePO 4 with dopamine to enhance the wettability of the LiFePO 4 electrode. The electrochemical process can be expressed by the following formula: (28) 3 I - + 2 Li + + 2 FePO 4 ↔ I 3 - + 2 LiFePO 4
Kanoh and his team first reported the feasibility of electrochemical lithium ion pumping based on the principle of lithium–ion batteries . They used λ–MnO 2 –modified platinum electrode as a working electrode, calomel electrode and platinum wire electrode as reference electrode and counter electrode respectively.
Test results show that this system has excellent lithium ion extraction capacity and cycle performance. After one cycle, Li/Na can be enlarged by 4300 times (Li/Na in the original solution = 0.01 and Li/Na on the final electrode = 43). In addition, for seawater with extremely low Li concentration, this system can still operate normally.