Methanol and proton transport control by using layered double hydroxide nanoplatelets for direct methanol fuel cell

Layered double hydroxides (LDH) were incorporated into polyelectrolyte membranes in order to investigate the electrochemical reaction processes affected by transport rates of methanol and protons in direct methanol fuel cell (DMFC) applications. Depending on different ion exchange capacities and its compositions of LDH, the polyelectrolyte membranes gave different diffusion coefficients of methanol and proton conductivities, which were successfully correlated with the maximum power density of a single-cell DMFC. Decreasing the diffusion coefficient of methanol, the open circuit voltage was increased and the overall performance of DMFC was improved by incorporating LDH nanoparticles. An optimal property condition was observed when the proton conductivity and the diffusion coefficient were balanced in a desirable manner providing a 24% increment of the maximum power density compared with the pristine Nafion membrane at 5 M of methanol feed concentration. The developed nanocomposite technique identified the effects of the diffusion coefficient and proton conductivity of polyelectrolyte membranes in the electrochemical reactions of DMFC.