Water Soluble Binder, an Electrochemical Performance Booster for Electrode Materials with High Energy Density

Abstract Binders, though often used in small doses, play a crucial role in determining the electrochemical performance of lithium ion batteries with high energy density. The traditional PVDF binder, which interacts with electrode materials via weak Van der Waals forces and consequently lacks the necessary capabilities (e.g., the suppression of significant volume variations, the interface maintenance etc.), could not fulfill the high demands of batteries with high energy density. Besides, extensive usage of the PVDF binder in the lithium ion battery is cost‐ineffective and may raise environmental concerns as its handling often needs the assistance of organic solvents. Herein, recent progresses on the development of novel eco‐friendly, low‐cost and water‐soluble binders which recently have gained increasing attention as a promising performance booster for lithium ion batteries with high energy density are reviewed. Such water soluble polymer binders are either natural, or modified, or synthesized, and they were observed with profoundly enhanced chemical/physical interactions with the electrode materials, stronger mechanical adhesion and evidently improved volume variation durability, leading to dramatic improvements in the electrochemical performances of Si‐based anodes, spinel/layered oxide cathodes and S cathodes. Perspectives for future research directions on water soluble binders are also discussed.