Island-like CeO2 decorated LiMn2O4: Surface modification enhancing electrochemical lithium extraction and cycle performance

Abstract

Extracting lithium from salt lakes is an effective way to relieve the shortage of lithium resources. Electrochemical lithium extraction has attracted wide attention due to its high selectivity, eco-friendliness, and high-efficiency. Functional surface coating is an effective approach to improve the cycling performance, stability, and conductivity of the electroactive materials. In this work, LiMn2O4 (LMO) electrode materials were prepared via sol–gel method with island-like CeO2 coating (CeLMO) for lithium electrochemical adsorption from simulated brine. CeO2 is helpful to inhibit the agglomeration of active metal oxides and promote the contact and electron transfer between metal oxides. Based on the results from X-ray diffraction, X-ray photoelectron, and Raman spectroscopy, the fate of lithium intercalation and deintercalation in CeLMO is illuminated. CeLMO-2//Ag electrochemical system can produce 96% pure Li+ from Li2CO3 precipitated mother liquor, and the adsorption capacity is 36.52 mg·g−1. The capacity retention after 30 cycles was 60% at 50 mA·g−1, and the Mn dissolution loss rate is 0.016%. In summary, island-like oxide coating improves electrochemical lithium adsorption efficiency and is a promising technology for producing battery-grade lithium products.