Electropolymerization reaction-driven 2,6-naphthalenediamine monomers to a multilayered sheet structure for ultralong cycling aqueous zinc-ion batteries

Abstract

Organic materials are attractive for energy storage due to their stable structure, environment-friendly nature and sustainability. In this work, a 2,6-naphthalenediamine (2,6-NAPD) monomer was first used as the cathode material in aqueous zinc-ion batteries (ZIBs). Electropolymerization by the initial electrode reaction eliminates energy consumption in the beforehand polymerization process and provides a simple method to synthesize polymeric cathode materials. The possible bond connection mode of 2,6-NAPD monomers was proposed using the ¹³C-nuclear magnetic resonance and Fourier-transform infrared spectra. Scanning electron microscopy shows that the irregular 2,6-NAPD monomers form multilayered sheets after long-term cycling. The 2,6-NAPD electrode delivers a specific capacity of 133.1 mA h g⁻¹ at 0.05 A g⁻¹ and excellent cycling stability with a capacity retention of 76.5% over 8000 cycles.