Abstract

Functionalized organic electrodes are most suitable for anodic part in sodium-ion (Na-ion) batteries due to eco-friendly nature, low cost, and to modify the structure. A very basic organic acid molecule, which is terephthalic acid (TPA) is synthesized from the environmental contaminant waste resource, polyethylene terephthalate (PET) water bottle via solvothermal method. The thermal instability and electrochemical performance of TPA have been improved through the formation of disodium terephthalate (Na2TP) by an acid-base reaction through the replacement of H+ ion from the acid molecule by Na+ ion. The electrochemically active Na2TP obtained from the waste PET bottles promises its usage as anodes for rechargeable Na-ion batteries. The average specific discharge capacity of Na2TP-55% exhibits 190 mAh g(-1) with 97% coulombic efficiency (CE) and Na2TP/SWCNTs composite show an impressive average specific discharge capacity 241 mAh g(-1) at C/10 rate with 98.5% CE along with stable cycling up to 50 cycles. The present approach to sustainably use discarded PET waste not only curbs polluting the environment but also foresees the future with a plastic-free environment by the sustain-able conversion of solid PET bottle wastes into usable electrodes for energy storage systems with benefits such as low manufacturing cost and effective solid waste removal. (C) 2021 Elsevier B.V. All rights reserved.