Carbon Nanotubes Modified Solid Electrolyte-Based Structural Supercapacitors and their Temperature Influence

In the present work, we reporton structural supercapacitors which are based on NASICON-type solid electrolyte Li1.4Al0.4Ti1.6(PO4)3(LATP). The nanostructuredelectrodes incorporate single-wall carbon nanotubes (SWCNTs) mixedwith the LATP electrolyte. The complete energy storage devices are manufactured ina sandwich structure consisting of two nanostructured electrode layers which are separated by a pure LATP layer.The as-prepared specimens are embedded in composite materials with Airstone880/886H epoxy resin as matrix. Theirelectrical properties are characterized by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Atambient temperature, the addition of 6.5 wt.% SWCNTs results in a distinct improvementby reducingthe total resistance of the embedded devices and enhancesthe capacitance from 0.025 mFg-1to 3.160 mFg-1at a scan rate of 5 mVs-1. Electrical measurements of two types of specimens are then applied underdifferent temperatures from ambient temperatureto 80 °C. It is observed that theequivalentseriesresistance (ESR) of device with SWCNTs decreases greatly and capacitanceincreases comparing with the device without SWCNTs. As a conclusion, the structural supercapacitors acquire excellent performance through high efficient double layer effectsrealized by nanostructured electrode/electrolyte interphase (large surface electrode areas)