Aqueous-Processable Redox-Active Supramolecular Polymer Binders for Advanced Lithium/Sulfur Cells

Lithium/Sulfur (Li/S) cells are a promising chemistry with potential to deliver a step-change in energy density compared to state-of-the-art Li-ion batteries. To minimize the environmental impact of the Li/S cell manufacturing and to compete with Li-ion cells in both performance and cost, electrodes cast using an aqueous process are highly desirable. Here we describe the discovery and application of a lithiated redox-mediating supramolecular binder based on the well-known n-type semiconductor, perylene bisimide, that forms high-fidelity sulfur electrodes from water-processed slurries. A 1.4-fold improvement in sulfur utilization at 3.0 C and 58% increase in capacity retention after 250 cycles at 1.5 C are reported for the prelithiated, supramolecular binder compared to control samples. These improvements are attributed to the self-assembly of lithiated perylene bisimide binders in water to yield nanowire web morphologies that increase interfacial area between electrode components and exhibit enhanced electrode-current collector adhesion.