Alkali metal ion storage of 2,6-naphthoquinone molecules encapsulated in single-walled carbon nanotubes

Due to its lower cost, environmental friendliness, and higher energy density, 2,6-naphthoquinone (NQ) demonstrates potential as an electrode material in lithium/sodium ion batteries. However, the limitations of poor conductivity and easy dissolution in electrolyte hinder its practical application. In this study, we employed single-walled carbon nanotubes (SWCNTs) as a protective capsule for encapsulating NQ molecules to address these challenges. The characteristics of NQ molecules encapsulated within SWCNTs (NQ@SWCNTs) were investigated using thermogravimetric analysis, x-ray photoelectron spectroscopy, x-ray powder diffractometry, and Raman measurements. Charge–discharge experiments of lithium/sodium ion batteries were conducted on both pristine NQ molecules and NQ@SWCNTs. Furthermore, we discussed the observed disparities in charge–discharge curve between NQ@SWCNTs and bare NQ.