This study uses fuel cell gas diffusion layers (GDLs) made from carbon fiber paper containing carbon black in proton exchange membrane fuel cells (PEMFCs) in order to determine the relationship between carbon black content and fuel cell performance. The connection between fuel cell performance and the carbon black content of the carbon fiber paper is discussed, and the effects of carbon black on the carbon fiber paper's thickness, density, and surface resistivity are investigated. When a carbon fiber paper GDL contains 10 wt% phenolic resin and 2% carbon black, and reaction area was 25 cm(2) and operating temperature 40 degrees C, tests show that a carbon electrode fuel cell could achieve 1026.4 mA cm(-2) and maximum power of 612.8 mW cm(-2) under a 0.5 V load. (C) 2007 Elsevier B.V. All rights reserved.