Strategies of binder design for lithium-ion battery cathodes

Lithium-ion batteries (LIBs) are crucial for advancing green energy transformation and boosting industrial competitiveness, due to their high energy density, long cycle life, and environmental friendliness. Among the key components of LIBs, cathode materials play a pivotal role in determining overall battery performance. However, these materials face several challenges, including phase transitions, electrolyte corrosion, and low conductivity, which hinder the development of high-energy LIBs. In addition to traditional modification strategies such as doping and micro-structural design, functional binders have emerged as a promising avenue to enhance the electrochemical performance of cathodes. Despite their potential, there is a lack of comprehensive guidance on designing functional binders for high-voltage or high-capacity cathodes, and the relationship between binder design strategies and cathode failure mechanisms is not yet well understood. This review addresses these gaps by summarizing the failure mechanisms of widely used cathodes (e.g., LiCoO2, LiNixCoyMnzO2, xLi2MnO3·(1−x)LiTMO2, LiNi0.5Mn1.5O4, and LiFePO4) in LIBs. We discuss the roles of functional binders in mitigating these failures and examine the associated failure mechanisms. Finally, we highlight design strategies for advanced functional binders and explore their potential to enable next-generation high-energy LIBs.