Direct lithium Extraction/Recovery System by Electrochemical Pumping Method

Abstract

With the rapidly increasing demand for lithium-ion batteries, it is an urgent task to develop technologies for the direct extraction of lithium from various resource sources, including salt-lake brine, which is difficult to extract with current technology, and for the recovery of lithium from spent batteries. In this paper, we focus on a promising approach to these challenges, the selective direct extraction and recovery of lithium by electrochemical pumping using lithium-ion conductors. First, we show that electrochemical pumping using lithium-ion conductors is capable of completely selective transport of lithium ions. Next, we discuss the lithium recovery rate, faradaic efficiency, and energy efficiency. Finally, we explain that electrochemical pumping using a two-power three-electrode cell, which is a new system devised by the authors, can significantly improve the lithium-ion transfer rate. Throughout this paper, we clearly explain that electrochemical pumping using lithium-ion conductors is a promising technology for the direct extraction and recovery of lithium.