Characteristics and direct methanol fuel cell performance of polymer electrolyte membranes prepared from poly(vinyl alcohol-b-styrene sulfonic acid)

• Published in: Electrochimica acta 2015-01, Vol.153, p.83-89
• Main Authors: Higa, Mitsuru, Feng, Shiyan, Endo, Nobutaka, Kakihana, Yuriko
• Format: Article
• Language: English
• Subjects: Block copolymers; Block-copolymer; Blocking; Crosslinking; DMFC performance; Electrolytes; Fuel cells; Membranes; Methanol permeability; Methyl alcohol; Permeability; Poly(vinyl alcohol); Proton conductivity; Sulfonic acid
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2014.11.155

Block type polymer electrolyte membranes (PEMs) were prepared by casting an aqueous solution of a block copolymer, poly(vinyl alcohol-b-styrene sulfonic acid) (PVA-b-PSSA), and by cross-linking the PVA chains with glutaraldehyde (GA) solution at various GA concentrations to investigate the effect of the cross-linking conditions on the properties of the block-type PEMs. The proton conductivity and the permeability of methanol through the block-type PEMs decreased with increasing GA concentration. The permeability coefficient through the block-type PEM prepared under the conditions of cGA=0.05% is about 6 times lower than that through Nafion115® under the same measurement conditions. A test cell for a direct methanol fuel cell constructed using the block-type PEMs delivered 32.4mWcm−2 of Pmax at 116mAcm−2 of load current density at 1M methanol solution, which is almost the same value obtained with Nafion115®. However, at high methanol concentrations (>9M), the Pmax of the block-type PEM was 17.8mWcm−2, and was 86% higher than that of Nafion®115.