The topic of batteries is often associated with heavy metals and their well-known issues. However, most of the batteries rely heavily on polymeric materials, which are responsible for crucial tasks in the cells.
The macromolecules can be utilized as active materials, where polymeric units are able to reversibly store electrons. Both thin-film and redox-flow batteries can apply this concept, replacing metallic active materials. This can make the batteries more environmentally benign, safer and less cost-intensive.
Furthermore, many state-of-the-art membranes are made up of polymers. Here, they regulate the ionic transport and ensure, that no electric contact between the different electrodes is made. Different types of membranes are known, some of which are able to function without additional electrolyte solvents, others are swollen in a gel-like state.
Another example of an application of macromolecules in batteries are binders. Here, the polymers act as a sort of glue between the different electrode materials and the substrates. The functional groups, side-chains and the overall chain length influence the adhesion and, thus, mechanical properties of the electrodes.
Scientists of the working group of Prof. Schubert recently published a review of the above mentioned fields of applications of polymers in batteries. This comprehensive article focuses on how the intrinsic properties of polymers influence the performance of different battery types. Mentioned battery types are organic batteries, redox-flow batteries (both organic and metal-based) and state-of-the-art lithium ion cells.
The original work with the title „Polymers for Battery Applications – Active Materials, Membranes and Binders” can be found here.