TY - JOUR U1 - Zeitschriftenartikel, wissenschaftlich - begutachtet (reviewed) A1 - Katzenmacher, Sven A1 - Kräling, Ulli A1 - Schroeder, Melanie A1 - Brämer, Regina A1 - Zengerle, Roland A1 - von Stetten, Felix T1 - Raney-platinum film electrodes for potentially implantable glucose fuel cells. Part 2: Glucose-tolerant oxygen reduction cathodes JF - Journal of Power Sources N2 - We report the fabrication and characterization of glucose-tolerant Raney-platinum cathodes for oxygen reduction in potentially implantable glucose fuel. Fabricated by extraction of aluminum from 1 μm thin platinum–aluminum bi-layers annealed at 300 °C, the novel cathodes show excellent resistance against hydrolytic and oxidative attack. This renders them superior over previous cathodes fabricated from hydrogel-bound catalyst particles. Annealing times of 60, 120, and 240 min result in approximately 400–550 nm thin porous films (roughness factors ∼100–150), which contain platinum and aluminum in a ratio of ∼9:1. Aluminum release during electrode operation can be expected to have no significant effect on physiological normal levels, which promises good biocompatibility. Annealing time has a distinct influence on the density of trenches formed in the cathode. Higher trench densities lead to lower electrode potentials in the presence of glucose. This suggests that glucose sensitivity is governed by mixed potential formation resulting from oxygen depletion within the trenches. During performance characterization the diffusion resistance to be expected from tissue capsule formation upon electrode implantation was taken into account by placing a membrane in front of the cathode. Despite the resulting limited oxygen supply, cathodes prepared by annealing for 60 min show more positive electrode potentials than previous cathodes fabricated from hydrogel-bound activated carbon. Compared to operation in phosphate buffered saline containing 3.0 mM glucose, a potential loss of approximately 120 mV occurs in artificial tissue fluid. This can be reduced to approximately 90 mV with a protective Nafion layer that is easily electro-coated onto the Raney-platinum film. KW - Elektrode KW - Brennstoffzelle KW - Glucose Y1 - 2010 SN - 0378-7753 SS - 0378-7753 U6 - https://doi.org/10.1016/j.jpowsour.2010.04.049 DO - https://doi.org/10.1016/j.jpowsour.2010.04.049 VL - 195 IS - 19 SP - 6524 EP - 6531 PB - Elsevier ER -