Electrochemical impedance spectroscopy is used to study novel cathode materials for lithium-sulfur batteries, based on commercial carbon and titania. Coin cells with Li anode are investigated at various stages of galvanostatic cycling.
For comparison, also symmetrical coin cells with a pair of positive (S/C/TiO2) or negative (Li) electrodes are studied. In addition to the application of titania as a barrier material impeding the polysulfide diffusion in the electrolyte solution, the inherent Li-insertion activity of TiO2 (anatase) and its contribution to the sulfur redox reactions is discussed.