Executive Summary : | Flexible electronic devices are emerging as new era for integrated medical applications, in flexible displays, artificial skins, and flexible electronic devices and hence, required portable and flexible energy storage devices. Present storage devices suffer through slow charging-discharging rate, limited cycle life, and lower energy density. Incorporated of liquid electrolytes in current energy storage devices resulted in unpredicted accidents due to solvent evaporation causing limited use in flexible devices. Flexible solid-state supercapacitors can overcome these issues with great flexibility of being bended, folded, rolled and integrated into flexible electronic devices towards flexible electronic applications. MXene, conducting polymers and rGO (reduced graphene oxide) possesses best potential candidature for supercapacitors (sCs). MXene and rGO are layer structured materials exhibiting good electrochemical performance but suffers through self-accumulation; resulted in reduced specific surface area due to van der Waals force leading to the limited ion diffusion and seriously deteriorates the supercapacitive performance. Interestingly, conducting polymer (CP) not only assembled in fibres form but also helps to avoid self-accumulation of MXene and rGO. In turn, MXene and rGO helps to improve the conductivity and mechanical strength of CP fibres and hence, MXene and rGO can be embedded in CP to take material mutualism. Furthermore, use of conducting polymer to form fibres yields mechanical flexibility along with high surface area. MXene and conducting polymer have pseudocapacitive nature which can deliver high capacitance and suffers through low stability; contrary, rGO exhibits electrochemical double layer capacitance (EDLC) and suffers through low capacitance but yields higher stability. Conducting polymer-Mxene and conducting polymer-rGO can yield high energy density through higher capacitance with higher stability. Hence, proposal focuses design of flexible solid-state supercapacitor using two electrodes on flexible conducting substrate; consisting of fibre of conducting polymer (thiophenes etc) -MXene (Ti, Mo, Cr, V carbides etc) and conducting polymer-rGO sandwiched by gel consisting non-conducting polymer and conducting electrolyte. symmetric or asymmetric configuration will be employed for flexible solid-state supercapacitor of large area (5 cm x 4 cm) and corresponding electrochemical performance will be obtained to get knowledge about specific capacitance, potential window, cyclic stability and mechanical bending stability and correlate them to well optimization of synthesis process and in line-with characterization. To demonstrate technology readiness level-3 (TRL-3), practical demo to run small flexible medical device will be given by using series combination of formed devices. |