Title: Green algae-based biopolymers for green energy storage devices

Abstract

Portability, flexibility and low environmental impact are among the most important features that novel energy storage devices must fulfill. Electrolytes are one of the main components of such devices. Polymer electrolytes feature low weight, flexibility and safety, compared with traditional liquid electrolytes. Biopolymers have also been used as solid electrolytes with good results. In particular, sulfated polysaccharides such as carrageenan and alginate, have shown to be good candidates for the development of novel bio-based electrolytes. The anionic nature of sulfated polysaccharides allows them to form coordination sites with metal cations and increasing ion dissociation. Ulvan is a sulfated polysaccharide synthetized by green algae. In spite of the fact that green algae are potential sources of polysaccharides, only brown and red algae are utilized at a commercially. In this paper, we use green algae to extract ulvan in order to develop a novel solid flexible electrolyte that could potentially be used in an energy storage device. We have characterized the ulvan extracted from ulva sp. by means of Gel Permeation Chromatography (GPC), Fourier-transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). The ulvan extracted was used to prepare films which dielectric properties were evaluated using Broadband Dielectric Spectroscopy (BDS). Ulvan-based films doped with different salts were evaluated and showed that ulvan is a good candidate for the development of green solid electrolytes for novel energy storage devices.