Electrical and Mechanical Properties of LiAlTi(PO4)3 Solid Electrolyte Based Power Composites

Abstract

Developing high capacitance electrical energy storage devices with weight/volume-saving properties is a highly desired goal of the energy engineering community. A novel type of composites, the multifunctional power composites, promises to become such materials. These materials have advantages as storing the electrical energy and bearing mechanical loads simultaneously. In the present researches, solid electrolyte is utilized for multifunctional power composites to avoid the leakage problem aroused by liquid electrolytes. The NASION-type ceramic Li1.4Al0.4Ti1.6(PO4)3 executing as solid electrolyte is successfully synthesized by sol-gel method. The as-prepared samples are embedded into fiber composite material using the aviation approved resin RTM6 with the Differential Pressure-Resin Transfer Molding (DP-RTM) process. The electrical properties for samples before and after embedding process are characterized by electrochemical impedance spectroscopy (EIS) as well as cyclic voltammetry (CV). Results show that, Li1.4Al0.4Ti1.6(PO4)3 possesses a conductivity of ~3×10-4 S/cm and a specific capacity of ~55 µF/g at room temperature before embedding. Conductivity and specific capacitances reduce after embedding process to some content. The mechanical properties are characterized by four-point-bending tests. The same composites without Li1.4Al0.4Ti1.6(PO4)3 are used as reference samples comparing with multifunctional power composite samples. Besides, a combination of cyclic voltammetry with four-point-bending tests has been applied as a coupling method to investigate the influence of bending loads on capacitance which indicate a stability of electrical properties of multifunctional power composites under bending loads. The developed Li1.4Al0.4Ti1.6(PO4)3 solid electrolyte-based multifunctional power composites offer a remarkable potential of multifunctional materials for future energy storage devices.