Advanced cathode binders for lithium-ion batteries: Molecular design and performance enhancement

As essential components in lithium-ion batteries (LIBs), polymer binders serve the fundamental purpose of effectively binding active particles and conductive agents to the current collector, thereby ensuring the structural integrity and stability of the electrodes. Although polyvinylidene fluoride (PVDF), the conventional cathode binder, is extensively utilized in lithium-ion batteries, it faces significant challenges, including limited adhesion, insufficient mechanical strength, and poor ionic conductivity. In response, significant research efforts are directed toward developing multifunctional polymer binders with improved adhesion, stability, and conductivity to satisfy the increasing demands for performance, cost-effectiveness, and environmental sustainability in advanced LIBs. This review systematically examines recent progress in cathode binder technology, encompassing: (1) comparative analysis of oil-soluble and water-soluble binder systems and their respective influence mechanisms on different cathode materials; (2) systematic summary and analysis of the necessity and preparation methods of functional conductive binders. Finally, we outline the future development prospects and challenges in next-generation binder development.