NaClO_4 added, corn and arrowroot starch based economical, high conducting electrolyte membranes for flexible energy devices

摘要

The increasing flexible and wearable electronic technology, demands cost effective and flexible energy devices which aresafe to human body. Hence the benign biodegradable materials are becoming important class of materials for wearableenergy devices. Starch is one such potential host renewable polymer which is abundant in nature and economical. Beinga food ingredient, it is safe for human body. Its properties depends upon the amylose and amylopectin content in it andhence two different starches, corn (～ 27% amylose) and arrowroot (～15% amylose) are modified by sodium salt (NaClO_4)and glutaraldehyde to develop flexible, transparent and free standing electrolyte membranes with high conductivity(> 10~(–3) S/cm). They have wide electrochemical stability window (> 2 V reaching upto 3.5 V) and low ESR. The relaxationtime is of the order of μs and the cyclic voltammetry has indicated EDLC type of charge storage. At low frequency, thevalues of C_p/C_s are approaching to 1, indicating that all the available charges are polarizable and contributing to chargestorage. The resonance frequency and frequency (f_(−45°)) at which phase angle is −45°, are in kHz frequency range, i.e.the working frequency range is quite high. Electrolytes having corn starch (i.e. greater amount of amylose) have betterperformance on every electrochemical figure of merit.