Wearable fabric supercapacitors using supersonically sprayed reduced graphene and tin oxide

Reduced graphene oxide (rGO) decorated with tin oxide (SnO₂) is deposited on a fabric via supersonic spraying to produce wearable supercapacitor textiles. rGO improves the electrical conductivity of textiles, while SnO₂ provides energy storage capabilities. The synergetic effect of the combination of rGO and SnO₂ on the overall electrochemical performance of the supercapacitor was studied by varying the SnO₂ concentration. The intermixed rGO flakes and SnO₂ nanoparticles enhanced the charge transport within the composite electrode, ultimately improving the overall electrochemical performance. The porous structure of the fabric enables sufficient electrolyte diffusion into the deposited rGO and SnO₂, to promote the interfacial activity between the active electrode and electrolyte. The optimal sample exhibited the highest specific capacitance of 1008 mF⋅cm⁻² at a current loading of 1.5 mA⋅cm⁻², with a capacitance retention of 93% after 10,000 cycles. Stretching and relaxing cyclic tests up to N = 1100 demonstrate the mechanical durability of the wearable supercapacitor. These promising results confirm that supersonic spraying is suitable for producing energy storage devices on wearable fabrics.