Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE Illustration for the mechanism of TFN membrane for VRB application.

ABSTRACT
In order to improve the selectivity of the porous membrane for vanadium redox flow battery (VRB), a thin film nanocomposite (TFN) membrane is constructed by incorporating hydroxylated hexagonal boron nitride into the skin layer of the polyether sulfone/sulfonated polyether ether ketone porous substrate (M
0) via the interfacial polymerization method. By employing the stable polyethyleneimine and cyanuric chloride monomers, the as-prepared TFN membrane not only exhibits high selectivity but also high stability for VRB application. As a result, the VRB assembled with the optimized MB0.6 TFN membrane shows the highest coulombic efficiency (CE) of 99.3% at a current density of 80 mA cm−2, and the highest EE (energy efficiency) of 88.4% at a current density of 40 mA cm−2. As a comparison, at the same current density, the CE and EE of the VRB assembled with M
0 are only 90.0% and 73.2%, respectively, and the CE and EE of the VRB assembled with commercial Nafion 115 are 91.7% and 73.8%, respectively. Furthermore, the MB0.6 membrane presents stable cell performance with no significant decay of cell efficiencies during a 100 cycles test. The results indicate that the composite membrane with high selectivity and stability has potential as an alternative to Nafion in VRB application.