Li-S cells have a low voltage (∼ 2.1 V), but their potentially high energy density (200-500 Wh/kg) makes them a promising system for next generation batteries. To obtain high energy densities on cell level, the weight fraction and load of the active material should be as high as possible, while inactive material is reduced to a minimum. Conventionally, sulfur slurry cathodes with an aluminum current collector are used. However, binder-free CNT-coated carbon structures are a promising method of achieving higher loads and higher ratios of active material. Using a specially designed test cell it was demonstrated that sulfur cathodes without a metal current collector can deliver enough power to meet the requirements of consumer electronics at simultaneously high capacities of up to 600 mAh g −1 for the entire electrode and current collector. A literature study compared various equivalent circuits used for Li-S electrochemical impedance spectroscopy (EIS), and enabled the selection of the most suitable one for the system used here. EIS measurements during charge and discharge delivered vital information about the specific resistances of the sulfur cathodes with a carbon current collector.Li-S cells deliver high theoretical capacities of 1672 mAh g −1 at a relatively low average discharge voltage of ∼ 2.1 V, thus providing energy densities of around 200-500 Wh kg −1 on cell level. In most publications, electrodes with sulfur loadings below 2 mg cm −2 are reported, 1 leading to active mass ratios clearly below 40% for the entire electrode and current collector. We believe that this ratio can be improved in some applications with smaller cell size (e.g. smartphones) by replacing the polymer binder and the metal current collector with a carbon current collector in a binder free sulfur cathode.Recent publications also show a growing interest in binder-free electrodes: Elazari et al. demonstrated good sulfur utilizations between 50-60% with a microporous activated carbon fiber cloth and a sulfur load of 6.5 mg cm −2 . 2 Zhou et al. prepared a flexible CNTbased membrane (CNT-S: 2-3 mg cm −2 ) and obtained high capacities of around 700 mAh g −1 S at very high currents of 6 A g −1 . 3 The high rate performance of these CNT-based electrodes is confirmed by Su et al. who achieved around 900 mAh g −1 S at 4C. 4 Kim et al. examined the effects of high temperature conditions on cell capacity, rate capability and cycle durability of a vertically-aligned CNT electrode synthesized on a Ni substrate by a CVD process. 5 With a comparable electrode acceptable capacities of around 700 mAh g −1 S were reported at sulfur loads of 7.1 mg cm −2 and 90 wt% sulfur in the electrode. 6 Higher sulfur loads of up to 20 mg cm −1 with sulfur utilizations around 50% can be obtained with CNT-coated carbon fiber structures .7The electrode we applied also consists of CNTs coated on a carbon fiber structure by a CVD process with subsequent melt infiltration of sulfur. Our belief is that that the optimization of such a cathode can allow active material rat...