Preparation of a novel hollow porous LiMn2O4 film electrode (H-LMOE) and its improved performance for lithium extraction

Lithium extraction from the solution in low Li+ concentration by an energy-saving and high-efficiency method is still a challenge. Herein, a novel hollow porous LiMn2O4 (H-LMO) with highly active site was proposed to enhance the extraction performance of Li+. Based on the established hollow porous structure, the H-LMO film electrode (H-LMOE) exhibits excellent lithium electrosorption performance and stability. Under the current density of 0.5 C, the electrosorption capacity of Li+ could reach 31.52 mg/g, the separation coefficient of Li+/Mg2+ was 581.67, and the energy consumption was as low as 0.49 Wh/mol Li. This unique structural strengthening mechanism made H-LMOE maintain a good Li+ extraction performance even in a solution of low Li+ concentration. The Li+ electrosorption capacity of H-LMOE was 2.13 times that of T-LMOE in a 60 mg/L Li+ solution, while the specific energy consumption of the H-LMOE was 15.78% lower than that of the traditional-LiMn2O4 film electrode (T-LMOE). Even in a 10 mg/L Li+ solution, the electrosorption capacity of H-LMOE was 21.48 mg/g, which was 10.0% higher than that of T-LMOE. Moreover, after 50 recycling processes, the final electrosorption capacity of the H-LMOE was about 25.0% higher than that of the T-LMOE.