Production and characterization of aramid aerogel separators for lithium ion batteries

Abstract

Due to the increasing demand on energy storage systems, many advancements have been made in order to produce high capacity energy storage devices. . Lithium ion batteries have been an interest in years since they indicate promising potential in energy storage systems for a wide range of industries including automotive, mobility, electronics, medicals etc. Performance of a lithium ion battery is affected by the characteristics of its components which are anode, cathode, electrolyte, and separator. Separators are critical components since they preclude short circuit in battery by preventing physical contact of anode and cathode. Separators should possess mechanical stability to withstand external loads, chemical inertness to the aggressive electrolyte medium, large porosity in order to allow ionic movement, flame retardancy in case of thermal runaway, electrical insulation to avoid internal short circuit. Separators should also be thin enough with the maximum porosity to sustain fast ion mobility. Moreover, the pore sizes should be controlled, and uniform distribution of the pores should be provided. The production process and material choice in the separators will affect the properties of the final product. In this study, aramid aerogel separators were produced from waste aramid textiles as a result of processes starting with deprotonation and ending with freeze-drying. Aramid nanofiber dispersion is reinforced with nanoparticles to improve physical properties. In this study, the effect of 3 different nano-sized particles, namely Al2O3, TiO2 and nanoclay, on the aerogel structure was investigated. The effects of process and material changes in the production process on the final product were determined.