Toward a Four‐Electron Redox Quinone Polymer for High Capacity Lithium Ion Storage

Abstract

Abstract Despite recent advances, current polymeric organic cathode materials have failed to incorporate a high degree of lithium storage in a small molecular framework, resulting in low capacities relative to monomers. This report discloses the development of a lithium salt polymer of dihydroxyanthraquinone (LiDHAQS) capable of storing four Li + per monomer. The combination of storing four Li + per monomer and a low molecular weight monomer results in a capacity of 330 mA h g −1 , a record for this class of material. The additional redox events responsible for added Li + storage occur between 3.0 and 3.6 V versus Li/Li + resulting in an average discharge potential of 2.5 V versus Li/Li + . These metrics combined yield a high energy density of 825 W h kg −1 which is a 55% improvement over commercial lithium cobalt oxide. The high performance of LiDHAQS makes it a promising material for next generation Li + cathodes.