Abstract

Lithium-ion batteries (LIBs) have become a core technology for a wide range of energy-storage applications due to their high energy density and long cycle life. Within the electrode, the binder, which holds together the active materials, conductive additives, and current collector, plays a critical role in maintaining structural stability and ensuring stable electrochemical performance. However, conventional binders, such as poly (vinylidene fluoride) (PVDF) and water-based systems, are often unable to effectively accommodate the volume expansion or prevent interfacial degradation during repeated charge–discharge cycles. In this context, polyimide (PI) has emerged as a promising next-generation binder material owing to its excellent thermal and mechanical stability, as well as its tunable molecular structure enabled by diverse functional groups (e.g., –COOH, –NH2, –O–, –SO3H, –CF3). This review systematically examines PI binder synthesis strategies, structure– property relationships, and their applications in major electrode systems, including LFP, NCM, and Si-based anodes. In summary, polyimides are identified as high-performance multifunctional binders capable of stabilizing the electrode–electrolyte interface, enhancing ionic transport, and mitigating volume expansion. These structural design strategies provide important guidance for the development of next-generation high-energy-density LIBs.

Keywords: polyimide binder;multifunctional binders;lithium-ion batteries;high-voltage cathode;silicon anode