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arXiv · 2602.13432

Eco-Friendly Supercapacitor Architecture Based on Cotton Textile Waste and Biopolymer-Based Electrodes

Luis Torres Quispe·Clemente Luyo Caycho·Javier Quino-Favero·Silvia Ponce·Abel Gutarra
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Abstract

This study presents an eco-friendly and bio-based symmetric supercapacitor using cotton textile waste-derived hydrogels as electrolytes and chitosan-based carbon electrodes as metal-free charge-storage components. Cotton-derived hydrogels were synthesized via an alkaline dissolution-gelation route and modified with ammonium thiocyanate (NH4SCN) to enhance ionic conductivity. The ionic modification increased the hydrogel conductivity from 17.1 to 37.8 mS cm^-1, confirming a nearly twofold improvement in ion transport efficiency. The resulting hydrogel exhibited improved thermal stability, homogeneous ionic transport, and strong polymer-ion interactions confirmed by FTIR and TGA analyses. In a symmetric device, the ion-modified hydrogel enables reduced equivalent series resistance, faster charge-transfer kinetics, and a short time constant (tau = 3.2 s), comparable to commercial energy-storage systems. After 1000 cycles, the device exhibits a 12.3% increase in specific capacitance, confirming stable proof-of-concept operation. Cycling leads to a moderate increase in R_ESR (18 to 22 ohm) and tau (3.2 to 4.1 s), indicating slower charge-ion redistribution. Notably, this R_ESR includes the contribution of the test-cell setup; in compact coin-type configurations, the resistance would be considerably lower. EIS reveals a concurrent rise in interfacial resistive terms, consistent with post-cycling hydrogel darkening and FTIR evidence of Fe-SCN coordination, suggesting that resistance buildup mainly originates from minor Fe-SCN interactions when the expelled liquid reaches the stainless-steel collector, rather than from loss of capacitive functionality. Overall, these results demonstrate the viability of cotton waste-derived hydrogels and chitosan-based electrodes as sustainable components for green energy storage, offering a recyclable and eco-friendly alternative to conventional systems.

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Luis Torres Quispe, Clemente Luyo Caycho, Javier Quino-Favero, Silvia Ponce, Abel Gutarra. 2026-02-13. Eco-Friendly Supercapacitor Architecture Based on Cotton Textile Waste and Biopolymer-Based Electrodes. https://arxiv.org/abs/2602.13432

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