The increasing flexible and wearable electronic technology, demands cost effective and flexible energy devices which are safe to human body. Hence the benign biodegradable materials are becoming important class of materials for wearable energy devices. Starch is one such potential host renewable polymer which is abundant in nature and economical. Being a food ingredient, it is safe for human body. Its properties depends upon the amylose and amylopectin content in it and hence 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 relaxation time is of the order of µs and the cyclic voltammetry has indicated EDLC type of charge storage. At low frequency, the values of C p /C s are approaching to 1, indicating that all the available charges are polarizable and contributing to charge storage. 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 better performance on every electrochemical figure of merit.

Single and fast ion transport in all-solid-state-flexible-electrolyte systems is desired for energy devices. The commercially used polymer electrolytes consist of liquid component to achieve the requiredelectrochemical properties and they also suffer from slow and poor cation transfer.Thepolymer-in-salt-electrolytes (PISEs) are supposed to lead to single and fast ion transport, unfortunately polymer hosts and salts,which can lead to successful synthesisof PISE with targeted minimum conductivity (10-4 S/cm) with suitable morphology is still to be identified.All efforts resulted either in poor electrochemical properties and/or poor morphology because of recrystallization of salt. Here novel PISEsare discussedwhich have high conductivity (0.1 S/cm) and small ion relaxation time (10 μ sec) with wide electrochemical-stability-window (> 2.5V). Since in PISEs the ion transport is decoupled from polymer segmental motion and it takes place through ion cluster, hence it is of immense importance to understand how the host matrix affects electrochemical properties of PISEs, hence three different starches (potato starch, corn starch and arrowroot starch) have been selected keeping all other constituent chemical and synthesis process same. Signature effects of host starches are observed and discussed.