Credit: Reprinted with permission from Nano Letters. Copyright 2015 American Chemical Society.
Flow batteries use two charged liquids separated by a membrane. The battery’s working ion must pass through the membrane while the active materials storing and releasing charge must stay sequestered in their respective electrode compartments. Now scientists, guided by simulations, have made a much more selective membrane (top left) from a polymer with tailored microporosity (right). The chemical structure of the polymer is shown on the bottom left. This specialized membrane greatly reduced active-material crossover, resulting in improved battery lifetime and efficiency.