Fig. 4: WD performance characterization and stability of BMs.
From: Continuous ammonia electrosynthesis using physically interlocked bipolar membrane at 1000 mA cm−2
Comparison of I–V curves for three BMs in a low current density and b high current density, measured in 0.5 M Na2SO4 aqueous solutions with a scan rate of 2 mA s−1. Inset of a shows determination 1st limiting current density. Inset of b shows photography of BP1 image after one I–V cycle from 0 to 1000 mA cm−2. c Comparison of I–V curves for BMs up to 1000 mA cm−2 (inset is I–V curve in low current density) using unsymmetrical 1 M HCl/1 M KOH electrolytes with a scan rate of 2 mA s−1. d Physical stripping strain of AEL–CEL of bipolar membranes in wet state versus offset measured as shown in inset schematic. e Long-term WD stability measured in 0.5 M Na2SO4 at 300 mA cm−2 over 550 h. The gray and mazarine plots represent the flat interface BM and MBM, respectively. Upper two insets show the microscopic structure of the AEL–CEL interface of the BMs; the lower two schematically show the mechanism of ballooning of flat interface BM (left) and that alleviated by MBM (right). f Comparison of electrochemical properties of BMs commercially available or reported recently (with advanced WD catalysts or structured interlayered design) based on dimensions of U100 and 1st limiting current density18,23,30,32,35,39,40,41,42,43,44,45,46,47.
