[en] Alkaline low temperature fuel cells are prepared and investigated; PTFE bonded gas diffusion electrodes for high current densities (about 400 mA/cm²) are prepared using a rolling technique. These electrodes are characterized by electrochemical and physical methods, focusing on preparation, reactivation process and degradation effects. After reactive mixing and rolling of PTFE (5-10 wt pc) with pre-activated and stabilized Raney nickel catalyst, the specific surface of the electrode is very small. The typical micropore systems (1.5-2.5 nm) of Raney nickel are not observed by BET-techniques. However, after electrochemical reactivation of the electrode, the active micropore system reappears depending on current density and activation time. The chemical surface composition of gas diffusion electrodes has been investigated by XPS techniques and electrochemical measurements depending on time of operation to get basic data for long term operation effects and degradation steps. From these experimental results, model considerations are discussed. 8 figs., 10 refs