Research on novel cathode structure of air-breathing micro-direct methanol fuel cell

Abstract

In this article, a novel cathode current collector with “cross” self-breathing configuration is proposed to improve the performance of self-breathing micro-direct methanol fuel cell. The simulation result shows that “cross” cathode micro-direct methanol fuel cell effectively improves the efficiency of oxygen mass transport and makes oxygen distribute uniformly which lead to high power density and temperature. The novel “cross” cathode structure and comparative high temperature promote rate of water evaporation which suspends flooding in the cathode, and the end of channel connects with atmosphere causing liquid state water on the gas diffusion layer to discharge outside directly. The self-breathing micro-direct methanol fuel cells with “cross” cathode structure are fabricated using micro-electro-mechanical systems technologies and are tested at room temperature. The experimental results show that the “cross” cathode micro-direct methanol fuel cell, whose peak power density is 17.1 mW cm⁻², exhibits significantly higher performance than the conventional perforated cathode micro-direct methanol fuel cell. Moreover, during the long-term operation of the “cross” cathode micro-direct methanol fuel cell, there is no water flooding on the cathode surface.