Conducting polymer composites as water-dispersible electrode matrices for Li-Ion batteries: Synthesis and characterization

Abstract

As battery materials increase in energy density, the likelihood of larger morphological changes during cycling increases. Current PVDF/carbon electrode matrices are ill-prepared for such materials and new battery electrode matrices are required. Typical strategies replace PVDF by aqueous binders, utilize other carbonaceous conductive additives or add small amounts of conducting polymers. In this study, we propose a class of water-processable, self-conductive electrode matrices that relies on the combination of polyelectrolyte binders with conducting polymers. By in situ polymerizing conducting polymer monomers in an aqueous solution of carboxylate-containing polymers, new electrode matrices are synthesized, in which components are intimately mixed at the nano-scale. Herein, the molecular composite polypyrrole:carboxymethyl cellulose (PPy:CMC), as a representative electrode matrix, allows the water-based electrode fabrication of carbon-additive-free electrodes. No additional binders and conductive additives are required to fabricate electrodes due to the adhesive and conductive features of PPy:CMC composites. This study paves the way for developing a promising type of electrode matrices for Li-ion batteries based on conducting polymer molecular composites that are adhesive and conductive, ensuring high-energy-density battery materials maintain active over more cycles. • Water-dispersible, self-conductive binder from low-cost, high-volume raw materials. • Simple synthesis and purification yields nano-composite of polypyrrole and carboxymethyl cellulose. • Binder is compatible with industry-typical slurry casting (tape casting). • Carbon additive-free lithium intercalation cathode operates at 1C.