M-aramid nanocomposite separators for energy storage applications

Abstract

Lithium-ion battery separators comprised of a nanocomposite of aramid polymer and alumina nanowires were presented as a new membrane architecture for more a thermally resistant and electrochemically superior alternative to the status quo. Porous membranes were produced by electrospinning low concentration m-aramid polymer (13%) with dispersed alumina nanowires. Resulting nanocomposite separators were non-woven mats that exhibited fast wettability, high integrity in thermo-gravimetric analysis tests up to 480C, and less than 10% area shrinkage when exposed to temperatures up to 280C. Physical, mechanical, thermal, and electrochemical figures of merit were discussed first from a practical standpoint then further examined in the context of the electrospun membranes. Results were contrasted with the performance of current state-of-art polyolefin separators. These m-aramid nanocomposite separators prove to be a strong candidate for batteries situated in demanding environments or large format batteries where safety is of paramount concern.