Conductivity studies and performance of chitosan based polymer electrolytes in H2/air fuel cell

Four chitosan-based electrolyte systems chitosan-H3PO4, chitosan-H3PO4-Al2SiO5, chitosan-H3PO4-NH4NO3 and chitosan-H3PO4-NH4NO3-Al2SiO5 were studied. The highest conducting sample at room temperature in each system have compositions of (in weight fraction) 0.62chitosan-0.38H(3)PO(4), 0.615chitosan-0.377H(3)PO(4)-0.008Al(2)SiO(5), 0.56chitosan-0.34H(3)PO(4)-0.10 NH4NO3, 0.5572chitosan-0.3383H(3)PO(4)-0.0995NH(4)NO(3)-0.005Al(2)SiO(5). The conductivity for the samples is (5.36 +/- 1.32) x 10(-5) S cm(-1), (1.12 +/- 0.18) x 10(-4) S cm(-1), (1.16 +/- 0.35) x 10(-4) S cm(-1), and (1.82 +/- 0.10) x 10(-4) S cm(-1), respectively. The open-circuit voltage of the fuel cells utilizing electrolytes with conductivity of the order 10(-4) S cm(-1) is similar to 0.9 V and the current density is greater than 20 mA cm(-2) at room temperature. Results show that the conductivity of the polymer electrolyte membrane influences the current density and performance of the fuel cell. Copyright (C) 2009 John Wiley & Sons, Ltd.