Review of Polybenzimidazole-Based Membranes in EnergyStorage and Conversion Devices: Conductivity Optimization ModificationStrategies

Abstract Polybenzimidazole (PBI) membranes are promising for energy storage and conversion applications, including fuel cells, redox flow batteries, and lithium-ion batteries, due to their thermal stability, chemical inertness, and proton conductivity. This review systematically examines key strategies for optimizing PBI membrane conductivity, including modulating molecular chain packing density of the PBI molecular structure, optimize the level of microphase separation, control the ability of imidazole protons, introduction of cross-linked block structure, optimization membrane hierarchy and constructing multicomponent composite systems. This review highlights the challenges in adapting PBI membranes to diverse applications, emphasizing the need for tailored designs and optimization strategies that account for specific operating conditions and electrolyte properties. By analyzing the operating mechanisms and failure modes of PBI membranes under various conditions, this review provides insights for developing high-performance, durable separators for energy storage and conversion.