Enhanced Cycling Performance of LiMn2O4 Electrode Including Cobalt and Vanadium Codoping for Lithium Extraction from Brine

This study explores the enhancement of LiMn2O4 (LMO) electrodes for lithium extraction from brine through cobalt (Co) and vanadium(V) codoping. Despite LMO's theoretical capacity, its practical application is limited by rapid structural degradation during cycling. The codoping strategy aims to improve the cycle stability of LMO while preserving its capacity. The LiCo0.025V0.025Mn1.95O4 (LCVMO) electrode exhibited a 30.8% increase in lithium diffusion coefficient and superior structural durability compared to pristine LMO. After 60 cycles, the LCVMO electrode retained a discharge capacity of 111.9 mAh g(-1), significantly higher than LMO's 77 mAh g(-1). Additionally, LCVMO demonstrated a low energy consumption (8.51 Wh/mol) and a high lithium adsorption capacity (18.7 mg/g) during extraction from simulated brine. UV-visible spectral analysis revealed that vanadium doping introduced two distinct band gaps (5.5 and 4.75 eV) in the LCVMO sample, compared to a single band gap of 5.25 eV in LMO, indicating enhanced conductivity. These findings suggest that Co and V codoping enhances the electrochemical performance of LMO, making LCVMO a promising candidate for efficient lithium extraction.