Composite waste-based aramid aerogel separators

Abstract

Lithium ion batteries are one of the most promising electrochemical energy storage systems. They generally consist of four components: anode, cathode, electrolyte, and separator. The separators are crucial for batteries since they prevent physical contact of electrodes and thus short circuit. In this study, reutilization of aramid fabric was highlighted by transforming it into a high value product: battery separator. A waste aramid fabric was used to synthesize aramid aerogels by deprotonation, sol-gel, and freeze-drying processes and then investigated as lithium ion battery separators. Aramid fabric was collected from a scrap plant of an industrial automotive company. Nanoclay or TiO2 nanoparticles were added into this waste-based aramid aerogel matrix in the sol-gel stage to further enhance the performance of the separators. The samples were characterized by scanning electron microscope (SEM), linear sweep voltammetry, electrochemical impedance spectroscopy (EIS) and galvanostatic charge/discharge tests. A uniform and bead-free morphology was observed for all samples with over 60% porosity. Electrolyte uptake and ionic conductivity test results showed that addition of TiO2 nanoparticles increased electrolyte uptake and ionic conductivity up to 365% and 2.2 mS/cm, respectively. The cells prepared by using nanocomposite aramid aerogels with TiO2 exhibited excellent cycling performance with a capacity of around 160 mAh/g in 200 cycles.