Synthesis and Properties of Ionic Polymers for Lithium Batteries

Ionic polymers are characterized by the presence of ionic groups that are covalently linked on the polymer chains, and possess unique physical and chemical properties. As a distinguished class of functional materials with important scientific research value and wide range of application prospects, ionic polymers have been utilized in the field of new energy, such as lithium batteries. The polymerization of ionic monomers and the post-modification of existing polymers are two main ways to realize the synthesis of ionic polymers. This review provides a brief overview of both cationic and anionic polymers, as well as zwitterionic polymers which are prepared through these two methods, and introduces the progress of these ionic polymers made in several critical areas such as electrolytes, protective electrode coatings and electrode binders for lithium batteries. In view of the significant impacts of the nature of repeating structural units and the types of ionic groups on the performance of the ionic polymer materials, which are crucial in determining the key properties including the ionic conductivity, ion transference number, electrochemical stability, mechanical strength and compatibility, there is a growing emphasis on the design and synthesis of novel ionic polymers with unique structures as well as conducting in-depth investigations into the relationships between polymer structure and material properties, which are expected to optimize the materials with enhancing properties and functionalities for specific applications, drive the further development of high-performance ionic polymer materials, and contribute significantly to the advancement of new-generation energy storage devices with improved safety, efficiency and stability.