Fig. 5.

a) Power curves of all the tested cathodes after running 13 days. Due to its instability, the plotted PVA-5 results are from 3 days (Fig. 3b). The two PTFE curves illustrate the repeatability of the results despite being different runs and materials. PTFE 1 stands for the first run (Fig. 2b) and PTFE 2 stand for the second run (Fig. 3b). b) Normalisation of the data by the carbon loading.