Synthesis and Characterization of Polymer Electrolyte Membrane Based on Cellulose-Chitosan-Alginate as Li-Ion Battery Separator

The current commercial Gel Polymer Electrolyte (GPE) products are generally made of synthetic and non-biodegradable materials. In addition, some of these polymers require toxic reagents and complex synthesis processes. The purpose of this research is to manufacture GPE membrane products using biodegradable raw materials, a combination of Hydroxy Ethyl Cellulose (HEC), Carboxymethyl Chitosan (CMCs), and Sodium Alginate (SA) with lithium salt as the electrolyte source. The methods start from the fabrication/synthesis of biodegradable GPE membranes in various compositions, then LiOH is added as an electrolyte source and glutaraldehyde as a crosslinking agent using a solution casting technique. The mechanical membrane testing (tensile strength and elongation) and characterization were carried out using XRD, SEM, and FTIR. Based on mechanical tests carried out, variations in HEC 50%: SA 50% has the highest tensile strength value of 81.4255 MPa and the lowest elongation value of 11.68%. The results of XRD analysis in the presence of a typical peak in the HEC: SA variation was 11.56º, which could affect the strength of the electrolyte-polymer gel membrane (GPE). The results of SEM analysis proved that the HEC: SA variation has a porous morphology that can affect the ion absorption capacity in lithium-ion battery applications. The results of FTIR analysis proved that there are functional groups S=O, CH, CO, NH, OH, and COC in the three membranes (SA, CMCs, and HEC).