Approaches to overcome the barrier issues of passive direct methanol fuel cell - Review

Direct methanol fuel cells (DMFCs) within all types of fuel cells are the most viable alternative to lithium-ion batteries in the portable application, and recently attracted much attention. This review provides a comprehensive overview of the passive DMFC barriers viz. methanol crossover, slow kinetics, water management, heat management, species management, durability and stability and cost for commercialization. Furthermore, it focuses on different approaches to overcome discussed barriers of passive DMFC. It is shown that the critical challenge regarding to minimize methanol crossover through the membrane using various hybrid membranes and methanol transport barrier so that the cell performance can be maximized. Regarding to reduce the catalyst cost with better kinetics, it is expected for developing non noble catalyst for passive DMFC. The challenges related to the operating temperature of passive DMFC is the selection methanol concentration, current density, ambient temperature, air humidity, cell orientation, membrane thickness, cell design, etc. which affects the cell performance. The several methods related to the water management layer deals with transport of the water produced on the cathode to the anode through the membrane and the cathode with minimum water flooding.