Understanding the Role of Polymer Interactions within Binders in Composite Lithium-Ion Anodes

The discovery of design principles for effective and robust binder systems is key toward pushing the boundaries of electrochemical performance in next-generation high-capacity anode electrodes. To achieve high-performing multicomponent binder systems, rational design of polymer formulations must be conducted to carefully tune the different physical, mechanical, chemical, conductive, and transport properties of the composite electrode. Here, we look at electrochemical performance through a polymer configuration lens to understand how intercomponent interactions of a co-binder polymeric system affect mechanical properties and electrochemical behavior of a magnetite composite electrode. By systemically changing the chain length of a poly(vinyl alcohol)/poly(acrylic acid) (PVA/PAA) blend, we investigate the effect of pairwise interactions between the polymers to shed light on mechanistic frameworks that affect electrochemical performance. We discovered that electrochemical results coincide with three polymer configurational regimes that depend on chain length. These results contribute to the growing body of work that aims to elucidate experimental design principles that aid in pushing development of binder systems for high-performing power-dense anode formulations.