V. Krishnadoss, A. Hesketh, C. Miller, W. Gray, E. Ellis, A. Kapetanakis, A. Patel, L. Filardi, H. Hawkins, I. Noshadi
Keywords: polymers , ionic liquid, 3D printing, capacitance
Summary:Polymers have been previously used as insulators and other structural materials, but when combined with appropriate salts in a liquid state (ionic liquid), there is an increase in ionic conductivity and other advantages over the conventional electrolytes. In this study, we harness this increase in conductivity for the use of polymers as electrolytes in a 3D printed energy storage device. The biocompatible ionic liquid electrolyte is prepared by conjugating the biopolymer Gelatin Methacrylol (GelMA) and ionic liquid (IL). The biopolymer- ionic liquid electrolyte and graphene as an electrode in a three-electrode system exhibits a specific capacitance of 200 F/g and were 3D printed to create an electrochemical capacitor that showed a specific capacitance of 16.33 µF/g at a current density of 1 A/g. The volumetric capacitance of the 3D printed energy storage device was found to be 44.07 µF/cm3. Implantable power sources built with biocompatible and biodegradable materials are of growing interest for future implantable medical devices. The biocompatibility of the energy storage device was also tested by implanting the device in rats. The potential low cost and easy manufacturability of 3D printed capacitors are of interest in the healthcare industry. The electrolyte synthesized exhibits good electrochemical stability and biodegradability, in cases where it is hard to access the implanted location such as intravascular applications biodegradable implants are favorable. The integration of an eco-friendly, biocompatible ionic liquid electrolyte provides a new perspective on energy storage.