High Performing Biobased Ionic Liquid Crystal Electrolytes for Supercapacitors

Production and storage of energy in a highly efficient and environmentally sustainable way is a demand of the current century to meet the growing global energy requirement. Design and development of novel materials and processes that allow precise control over the electrochemical behavior and conductivity of electrolytes is necessary for acquiring such targets. Development of ionic liquid crystals with ordered domains endowed with enhanced ionic conductivity from renewable resources is receiving much interest in this respect. In this paper, we report a unique strategy for the preparation and utilization of ionic liquid crystalline electrolyte derived from a renewable resource: cashew nut shell liquid; an abundantly available waste byproduct from cashew industry. We have prepared imidazolium-based ionic liquid crystal (PMIMP) from cardanol and studied its structure and liquid crystalline phase formation by various techniques. The symmetrical supercapacitor fabricated with mesoporous carbon electrodes employing PMIMP as electrolyte measured a specific capacitance of 131.43 F/g at a current density of 0.37 A/g with excellent cycle stability and 80% capacitance retention after 2000 cycles. All these excellent properties of the prepared ionic liquid crystalline electrolyte suggest its application as an efficient, environmentally friendly and low-cost electrolyte for energy storage devices.