Experimental Evaluation of Cell Temperature Effects on Miniature, Air-Breathing PEM Fuel Cells

Abstract

An experimental analysis of cell temperature effects on an air-breathing, PEM fuel cell is presented. The cell was tested in three active area sizes of 5 cm², 10 cm², and 25 cm². The cell’s design minimized the influence of self-heating by using a large thermal body in its construction which conducted heat away from the active area. This allowed for the use of a heater and controller to test a constant cell temperature uninfluenced by current density. Polarization and electrochemical impedance spectroscopy testing showed that at higher current density, elevated temperature increased the buoyancy of the air around the cell which improved open cell performance. However, the opposite is true for lower current density as membrane dehydration becomes more prevalent at higher temperatures. Schlieren imaging, in conjunction with the polarization and EIS data, shows how heated and more buoyant air boosts cell performance. Infrared imaging identifies temperature gradients on the active surface which may hinder cell performance slightly.

Key findings

• ▸Elevated temperature increases buoyancy of air around cell, improving performance at high current density.
• ▸Membrane dehydration becomes more prevalent at higher temperatures, hindering performance at low current density.
• ▸Temperature gradients on active surface identified by infrared imaging may slightly hinder cell performance.

Keywords

Identifiers

DOI

10.1115/fuelcell2011-54115

Journal

ASME 2011 9th International Conference on Fuel Cell Science, Engineering and Technology

Year

2010