Chitin for the Replacement of Fluoropolymers in the Assembly of Electrochemical Devices

Chitin and graphene/chitin composite films were prepared using ionic liquid processing and tested as separators and electrodes, respectively, in a supercapacitor to demonstrate the construction and function of an energy storage device which is constructed solely from bio-based polymer materials. The dry films possessed high thermal (Td = 265 and 246 °C) and mechanical (tensile strength = 5(1) and 1.7(2) MPa) stabilities. Once soaked in an aqueous electrolyte (2 M (NH4)2SO4) for use in a supercapacitor test cell, the device reached a peak capacitance value of 2.4 F/g. This work demonstrates a first step towards a scalable method for the preparation and assembly of biorenewable electrochemical devices, which avoid the use of unsustainable fluoropolymers and solvents, and is poised to be an important part of environmentally-sustainable economies.