Supercapacitors store energy within the double electrochemical layer at the electrode/electrolyte interface. In the traditional supercapacitorsm an ion permeable film soaked with liquid electrolyte is placed between high surface area electrodes. Replacing liquid electrolytes with a solid electrolyte may improve their reliability for high temperature, low dimensional and environment friendly and corrosion free applications. Proposal aims at development and characterization of all-solid-state supercapacitors using NASICON-polymer hybrid membranes as separators and high surface area electrodes. Applying various hybrid electrolytes prepared from Li⁺ ion NASICONs and polymer hosts, Electrochemical double layer capacitors (EDLCs), pseudo capacitors and Hybrid supercapacitors will be fabricated and characterized. Work thus would involve synthesis of Li⁺ ion based NASICON-polymer hybrid composite films and fundamental characterization (ii) development of button-type solid state supercapacitors (EDLC, Psudo and Hybrid) using novel NASICON polymer hybrid films as electrolytes and their characterization. And finally (iii) To understand the mechanism of charge transfer at the electrode-electrolyte interface and role of solid electrolyte in performance of supercapacitors.

Nature of the work:

Several interesting superionic/fast ionic solids have been developed, but grain boundary impedance (GBI) limits their applications to solid ionic devices. Project aims at development of novel NASICON based glass-ceramics for electrolytic applications in Li⁺ ion batteries. These glass-ceramics with high ionic conductivity will be prepared by a novel glass filler approach. Structure will be characterized by using FE-SEM, XRD, EXAFS and Raman spectroscopy. Further, electrical properties will be studied using impedance spectroscopy at low and high temperatures. Tailoring grain boundary impedance and exploring parameters that influence GBI will be explored. Thermal stability investigations will be performed using DSC, conductivity-temperature cycles. Finally, fabrication and characterizations of an all-solid-state battery using compositions developed in the laboratory.

Important Equipment  procured under DST SERB Project: