LiAlTi(PO4)3 Used as Solid Electrolyte for All-Solid Structural Supercapacitors

Abstract

Structural supercapacitors are very interesting multifunctional devices combining the properties of an electrical energy storage device and a structural component simultaneously. These types of supercapacitors are mostly equipped with solid state electrolytes, instead of traditional liquid electrolytes, avoiding leakage problems and supporting the mechanical performance of the composite materials. In the present study, the Lithium-ion based solid ceramic electrolyte Li1.4Al1.6Ti0.4(PO4)3 was successfully synthesized by sol-gel method. Its electrical properties were characterized by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Results show that Li1.4Al1.6Ti0.4(PO4)3 possesses a conductivity of 2.94×10-4 S/cm at room temperature and a specific capacity of 55.57 µF/g. The as-prepared samples were embedded into fiber composite material using the aviation approved resin RTM6 by an injection process, which served as a capsule for supercapacitor and made the composite structure flexible. Subsequently, the capacity and conductivity were tested getting values of 53.44µF/g and 2.00×10-4 S/cm respectively. The reason for electrical properties loss was investigated by computerized tomography (CT) and EIS tests and the results provide reference for the future research. Keywords: Multifunctional composite; Structural capacitor; Lithium-ion solid electrolytes; Electrical energy storage