Enhanced Performance of Direct Methanol Fuel Cell Using Talc Modified Nafion Membrane

Magnesium silicate hydroxide, Mg₃Si₄O₁₀(OH)₂, commonly known as talc, is employed to modify nafion for application in direct methanol fuel cell. Improved proton conductivity and reduced fuel permeability are shown by the talc/nafion composite membrane. Highest proton conductivity is achieved with 5% talc/nafion membrane, which is 27.14% higher than that of pure cast nafion membrane. However, 1% talc/nafion membrane reduced methanol permeability by 51% compared to nafion 117 and by 42% compared to pure cast nafion. Fuel cell performance was evaluated at varying methanol concentrations and temperatures. The talc/nafion membranes exhibited higher open circuit voltages and current density than both pure cast nafion and nafion 117. The highest current density is achieved with 1% talc/nafion with 3 M methanol at 80°C. At a constant cell voltage of 0.28 V, 155.95 mA-cm^-2 of current density is obtained with 1% talc/nafion, 6.4 mA-cm^-2 with pure cast nafion and 6.82 mA-cm^-2 with nafion 117.