Porous membrane with improved dendrite resistance for high-performance lithium metal-based battery

Lithium metal is one of the most promising anode materials for next-generation power batteries because of its high energy density and low reduction potential. Unfortunately, uncontrolled Li dendrite growth during cycling leads to an unstable interface, a limited cycling life, and a low Coulombic efficiency, further results in severe capacity decay and safety issues. To address these problems, an effective approach is proposed to realize uniform Li nucleation. Herein, we demonstrate a thermally stable polybenzimidazole (PBI) polymer for making porous membranes with a tuneable morphology via a versatile non-solvent treatment method for Lithium-ion battery's (LIBs) application. The final morphology of PBI membranes is controlled by selecting the appropriate non-solvent and an optimized performance could also be obtained. Notably, our functional porous PBI membrane with abundant polar amine functional groups could enable dendrite-free Li deposition, showing stable and low overpotential cycling durability for 400 h at a current density of 1 mA cm⁻². With such a membrane, the LiFePO₄/Li cell shows superior cycle stability and rate performance, which are higher than those of commercial PE separators. Remarkably, this work offers a simple and facile method to prepare advance porous membranes for lithium-ion batteries with improved dendrite resistance.