Polymers for Battery Applications—Active Materials, Membranes, and Binders

In the light of an ever-increasing energy demand, the rising number of portable applications, the growing market of electric vehicles, and the necessity to store energy from renewable sources on large scale, there is an urgent need for suitable energy storage systems. In most batteries, the energy is stored by exploiting metals or metal-ion-based reactions. However, nearly every modern battery would not function without the help of polymers. Polymers fulfill several important tasks in battery cells. They are applied as binders for the electrode slurries, in separators and membranes, and as active materials, where charge is stored in organic moieties. This review concentrates on recent research on polymers utilized for every aspect of a battery, discussing state-of-the-art lithium cells, current redox-flow systems, and polymeric thin-film batteries. The focus is on the properties of the polymers applied in different battery systems and how they affect their overall performance.