Advances in materials and fabrication of separators in supercapacitors

Abstract

Supercapacitors (SCs) have been extensively used in advanced energy applications due to their superior energy storage capacity and rapid charge–discharge rate. The significant constituents of a SC include two electrodes, an electrolyte and a separator. The integrated performance of all these constituents is necessary to enhance the energy storage ability of the device. For advanced electrochemical energy systems, the search for separator materials with higher ionic conductivity, mechanical strength, thermal stability, longer life and low cost of manufacturing is necessary. Appropriate design and fabrication of a separator improves the thermal stability, specific capacity, efficiency and life of a SC. In this review, a study on various materials that are used in the fabrication of separator membranes namely polymer, polymer–ceramic, and bio-based materials and the influence of these materials on the overall performance of the SC is presented. New trends in developing devices by integrating smart separator materials with SCs are also highlighted.