Rational Design of Naphthol Groups Functionalized Bipolar Polymer Cathodes for High Performance Alkali-Ion Batteries

Abstract

Redox-active organic compounds gather significant attention for their potential application as electrodes in alkali ion batteries, owing to the structural versatility, environmental friendliness, and cost-effectiveness. However, their practical applications of such compounds are impeded by insufficient active sites with limited capacity, dissolution in electrolytes, and sluggish kinetics. To address these issues, a naphthol group-containing triarylamine polymer, namely poly[6,6 '-(phenylazanediyl)bis(naphthol)] (poly(DNap-OH)) is rationally designed and synthesized, via oxidative coupling polymerization. It is capable of endowing favorable steric structures that facilitate fast ion diffusion, excellent chemical stability in organic electrolytes, and additional redox-active sites that enable a bipolar redox reaction. By exploiting these advantages, poly(DNap-OH) cathodes demonstrate remarkable cycling stability in both lithium-ion batteries (LIBs) and potassium-ion batteries (PIBs), showcasing enhanced specific capacity and redox reaction kinetics in comparison to the conventional poly(4-methyltriphenylamine) cathodes. Overall, this work offers insights into molecular design strategies for the development of high-performance organic cathodes in alkali-ion batteries.,The rational design of poly(DNap-OH) cathodes simultaneously enhances the electrochemical stability and redox potential by incorporating naphthol functional groups, leading to high specific capacity and improved electrochemical kinetics for alkali-ion batteries. Additionally, the electrochemical coupling reaction endows structural integrity and insolubility in organic electrolytes, and the porous structure and non-planar scaffold facilitate anion/cation transport. image,