For the measurements, Swagelok T-cells in a two-electrode setup were used, whereas Li (Ø = 3 mm; Aldrich) served as the anode. To avoid direct contact and thus, prevent the cell from an internal short circuit, metallic Li was shielded from the cathode electrode by a semipermeable glass fiber separator (What-man glass microfiber filters GF/F). To guarantee good Li ion transport during the measurement, 1M LiPF6 in a mixture of ethylene carbonate:dimethyl carbonate (EC:DMC) in a ratio of 1:1 acted as the liquid electrolyte.