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.

Pyrolysis of naphthol functionalized polytriarylamine for efficient sodium-ion storage

“…As reported in our previous reports, we prepare triarylamine monomer with phenolic functionality by introducing naphthol units to replace two benzene rings. 15 Poly(DNap-OH) was successfully synthesized via Cu-catalyzed oxidative coupling polymerization, where all details are presented in Fig. S1 and S2 (ESI†).…”

“…The naphthol-functionalized triarylamine monomer (DNap-OH) and polymer (poly(DNap-OH)) were synthesized following the previously reported procedure. 15 In a 250 mL round-bottom flask (RBF) fitted with a reflux condenser, a solution was prepared by combining DNap-OH (5.280 g, 14.00 mmol), di-μ-hydroxo-bis[( N , N , N ′, N ′-tetramethylethylenediamine)copper( ii )]chloride (325.2 mg, 1.06 mmol), and tetrahydrofuran (THF) (120 mL). The mixture was then stirred at 30 °C under an oxygen atmosphere for 2 h. Afterward, the reaction mixture was precipitated into methanol with a small amount of hydrochloric acid, followed by filtration with water and methanol.…”