Self-assembled nanostructures of PDI-bolaamphiphiles as anode materials for advanced rechargeable Na-ion batteries

Abstract

Organic electrode materials become more attractive for sodium-ion batteries (NIBs) owing to their structural flexibility, and eco-friendly nature. However, currently, they were confronted with less capacity and poor cycle stability. Herein, we synthesize various nanoarchitectures from PDI-bolaamphiphiles by employing a simple self-assembly strategy and exploited them as anode materials for NIBs. The simple structural mutation of amino acid side chain had shown a significant impact on morphology and performance of the battery. The NF (Nanofiber) electrode delivered a high average specific capacity of 271 mAh g−1 at a current density of 50 mA g−1 and displayed a remarkable rate performance and delivered exceptional capacity retention of 97% after 200 cycles. In addition, it was also surpassed the majority of organic anodes by retaining a capacity of 85%, after 1000 charge-discharge cycles, at a high current density of 1 A g−1. The mechanism of sodiation and desodiation during the charge-discharge process was revealed by qualitative and quantitative analysis. Altogether, the nanofiber structure of NF electrode enhances the electrochemical properties by accelerating sodication/de-sodication potentials and the carboxylic group reduces its solubility in the organic electrolyte, ensuring it a potential material for greener, sustainable, highly stable organic anode material for NIBs.