Flexible solid-state supercapacitor based on tin oxide/reduced graphene oxide/bacterial nanocellulose

We demonstrate a flexible and light-weight supercapacitor based on bacterial nanocellulose (BNC) incorporated with tin oxide (SnO₂) nanoparticles, graphene oxide (GO) and poly(3,4-ethylenedioxyiophene)-poly(styrenesulfonate) (PEDOT:PSS). The SnO₂ and GO flakes are introduced into the fibrous nanocellulose matrix during bacteria-mediated synthesis. The flexible PEDOT:PSS/SnO₂/rGO/BNC electrodes exhibited excellent electrochemical performance with a capacitance of 445 F g^-1 at 2 A g^-1 and outstanding cycling stability with 84.1% capacitance retention over 2500 charge/discharge cycles. The flexible solid-state supercapacitors fabricated using PEDOT:PSS/SnO₂/rGO/BNC electrodes and poly(vinyl alcohol) (PVA)-H₂SO₄ coated BNC as a separator exhibited excellent energy storage performance. The fabrication method demonstrated here is highly scalable and opens up new opportunities for the fabrication of flexible cellulose-based energy storage devices.