Lithium-Ion Exchange Membrane Water Electrolysis Using a Cationic Polymer-Modified Polyethersulfone Membrane

Abstract

Lithium-ionexchange membrane water electrolysis fabricatedwith a cation exchange polyethersulfone membrane exhibits improvedcell performance (1.13 A cm(-2) @ 1.7 V) owing tolow ohmic and charge-transfer resistance. We previously reported lithium-ion exchange membranewater electrolysisusing a commercial Nafion membrane for clean hydrogen production.In this study, a polyethersulfone (PES) membrane with high alkalinestability was dipped in a cationic aqueous solution to fabricate aPES-based membrane (c-PES membrane) as an alternative to Nafion. Comparedwith the commercial PES membrane, for the c-PES membrane, lithiumions can selectively transport from the anode to the cathode. Additionally,a high-porosity Ni-based porous transport layer (PTL) was used asan alternative to expensive Ti-PTL. Lithium-ion exchange membranewater electrolysis at 50 & DEG;C using c-PES membrane exhibited improvedcell performance (1.13 A cm(-2) @ 1.7 V) owing tolower ohmic and charge-transfer resistance, exhibiting the comparableperformance to the reported water electrolysis systems. The carbonateformed during the process was effectively removed by injecting deionizedwater followed by H2SO4 solution, resultingin stable cell performance for 200 h.