Performance Analysis of Direct Methanol Fuel Cell for Optimal Operation

Abstract

Direct methanol fuel cell (DMFC) is one of promising candidates for power sources of mobile devices. Efficient operation of fuel cell system is very important for long-sustained power supply due to limited tank size. It is necessary to investigate performance characteristics of the fuel cell stack for efficient control of the DMFC system. We have developed an electrochemical model of DMFC using experimental data. The generated voltage is modeled according to various operating conditions; methanol concentration, cell temperature, and load current. The crossover phenomenon is also included in cell model. The model fits the experimental data well within 10 percent error. It is found that the efficiency of the fuel cell is mainly dependent on concentration of the methanol solution. Maximum efficiency line exists at specific concentrations of methanol solution with respect to the amount of generated power. Also efficient control method of the stack is presented.

Analytical polarization curve of DMFC anode

“…In modeling of cells, stacks and systems, and in design of automatic control devices, a physically realistic analytical equation for the anode polarization curve is highly desirable. Many works utilize the Tafel law for the MOR rate in the electrode (Baxter et al 1999, Dohle et al 2000, Argyropoulos et al 2002, Murgia et al 2003, Yang and Zhao 2007, Casalegno and Marchesi 2008, Miao et al 2008, Cho et al 2009, Zhao et al 2009, Lam et al 2011. This extensive list reflects a great demand for a simple analytical expression for the MOR rate.…”

Modeling and optimization of the DMFC system: Relating materials properties to system size and performance

“…The direct methanol fuel cell (DMFC) is an electrochemical energy conversion device that operates by converting methanol and water to carbon dioxide and protons at the anode, CH 3 OH þ H 2 O # CO 2 þ 6H þ þ 6e À , and by reducing oxygen at the cathode, O 2 þ 4H þ þ 4e À # 2H 2 O. The primary advantage of the DMFC is that it can be operated with a liquid anode feed and therefore does not require a reformer or a bulky gas storage tank.…”