Nitrogen-doped carbon coated LiFePO4 with enhanced Lithium extraction kinetics and cyclic stability for efficient Lithium recovery

Efficient extraction of lithium from salt lake brine is vital to meet the soaring demand for lithium resources to support sustainable energy development. LiFePO 4 (LFP) has emerged as a promising electrode material for electrochemical lithium recovery due to its excellent Li + selectivity and structural stability. However, its poor electronic/ion conductivity limits its application. Here we report the synthesis of N-doped carbon coated LFP composite materials (LFP@NC) using melamine as the carbon and nitrogen source for efficient lithium extraction. The results demonstrate that the optimized LFP@NC-2% electrode can achieve an excellent Li + adsorption capacity of 5.2 mmol g −1 with high cycling stability, and Li + /Mg 2+ and Li + /Na + selectivity of 310.5 and 230.7, respectively. The obtained Li + purity is 89.7% in recovered solution. This superior performance of LFP@NC-2% can be due to the role of N-doped carbon coating layer on LFP, enhancing the interfacial electron/ion transport rate to thus reduce the internal polarization, and improving the structural stability of LFP. This work would be helpful for design and development of high-performance LFP-based materials for efficient electrochemical lithium extraction from the salt lake brine.