Abstract: Electrochemical de-intercalation/intercalation method for lithium extraction from brine has attracted more and more attention due to the high selectivity, the large adsorption capacity and the pollution-free. However, the high mineralization and viscosity of the brine lead to a lower actual lithium extraction rate. Based on this, NH₄HCO₃ was used as a pore-former to prepare porous LiFePO₄ electrodes with good permeability and mass transfer properties to improve the kinetic performance in the process of lithium extraction. The results showed that there was a composite structure of microcracks-microporosity formed on the surface of the electrode after the modification, which could significantly enhance the mass transfer process of the solution and reduce the electrochemical polarization. After the pore-forming modification, the special capacity of electrode increased from 25.6 mg (Li)/g (LiFePO₄) to 35.2 mg (Li)/g (LiFePO₄) during the electrochemical de-intercalation/intercalation process, and the average current density increased from 8.7 A/m² to 17.9 A/m², indicating the efficiency of lithium extraction has been significantly improved. In addition, the electrode exhibited good cycling performance with a capacity retention rate of 98% for 30 cycles.