(583j) Li4Ti5O12 Pouch Cell Battery System for Selective Lithium Recovery from Aqueous Resources
Electrochemical Li recovery from aqueous solutions is an attractive alternative to adsorption methods. An electrochemical system that suppresses the high energy requirement and offer high purity Li compounds at a shorter amount of time is necessary. Herein, a modified Li4Ti5O12 pouch cell battery system for electrochemical lithium recovery is presented. This hybrid reactor is composed of an anode in an organic electrolyte and Li-rich catholyte with Titanium foil or a porous carbon-based electrode as current collector. The two systems were integrated through an anode pouch cell assembly. It contained a lithium superionic conductor (LISICON) solid electrolyte in the open-structured top to separate the organic electrolyte from the aqueous electrolyte. Essentially, there were two reaction cells, one for Li capture and other for Li recovery. In Li capture cell, charging reaction of the system was the driving force to allow lithium ion (Li+) intercalation into the electrode inside the pouch cell. The Li-rich electrolyte was replaced with a suitable recovery solution to proceed with the Li+ release in a new cell. In the recovery cell, O2 (from air) passing through the cathode reacted with Li+ to form LiOH. On the other hand, if Li2CO3 is desired as the end-product, LiOH can be reacted with CO2 to form the carbonate product.
Repetitive cyclic voltammetry and galvanostatic cycling showed highly selective and stable electrochemical system for aqueous Li+ uptake and release. Overall, the hybrid electrochemical reactor is capable of selectively capturing Li+ at a fast rate and has a potential for high energy generation during the recovery process. Hence, this yielded an electrochemical Li recovery system that is environmentally benign and less energy intensive.
This research was supported by NRF funded by the Ministry of Science, ICT and future Planning (2017R1A2B2002109 and 2015R1A2A1A15055407) and the Ministry of Education (2009-0093816).