Customizing polymeric binders for advanced lithium batteries: Design principles and beyond

As society strides toward a sustainable future powered by lithium-ion batteries, the integral role of polymeric binders becomes increasingly evident. Historically serving as a film former and chemical adhesive that amalgamates the active host materials and conductive carbon in battery electrodes, their role has been redefined with the advent of innovative battery systems and host materials. These emerging technologies pose unique challenges, propelling the shift toward “customizable” binder designs. Polymeric binders should now ensure structural robustness, especially for high-capacity host materials, by leveraging varied intermolecular interactions to counteract internal stresses. Additionally, incorporating high-voltage electrode materials or electrolytes demands binders with an expansive electrochemical stability window. The interface energy control of binders is also critical, especially when incorporating dissolving cathodes or transitioning to solid-state electrolytes. This review provides a comprehensive understanding, breaking down the design principles of polymeric binders into three distinct paradigms: (1) structural design for high-capacity anodes, (2) electrochemical design for high-voltage cathodes or electrolytes, and (3) interfacial design for dissolving cathodes and solid-state batteries. Our discourse offers both a reflection on the evolving multifunctional nature of binders and a roadmap for future endeavors in the binder design for advanced lithium battery chemistries.