Metal Coated Conductive Fabrics with Graphite Electrodes and Biocompatible Gel Electrolyte for Wearable Supercapacitors

Fabric-based supercapacitors have received considerable interest as energy storage devices for wearable systems. This work demonstrates the use of metal coated fabrics as the active material and current collector with nontoxic polyvinyl alcohol (PVA)-KCl gel electrolyte for wearable supercapacitors (SCs). To evaluate the influence of the metal coating, the electrochemical and capacitive studies are carried out and results are compared with a newly developed metal free graphite printed textile (cellulose-polyester) (CP-Gr) based SC. It is evident that the homemade graphite paste electrode printed on the top of Armor FR (Ni/Cu coated polyester fabric) (AFR-Gr) and Nora Dell (Ni/Cu/Ag coated polyamide) (ND-Gr) based SCs with PVA-KCl electrolyte exhibits the specific capacitance of 99.06 and 46.88 mF cm⁻², respectively, at sweep rate of 5 mV s⁻¹. These values are 24 and 52 times greater than that of CP-Gr based SC. The AFR-Gr and ND-Gr based SCs have an excellent energy density of 8.81 and 4.17 µWh cm⁻², respectively, at 5 mV s⁻¹. The fabricated ND-Gr based SC gives a stable response for more than 5000 charging/discharging cycles. Finally, the nontoxic nature of the PVA-KCl gel electrolyte is evaluated and confirmed through in vitro cytocompatibility assessment with adult human dermal fibroblasts cells for wearable applications.