The effects of the multifunctional CNTP/TiO2 barrier for Li–S batteries are elucidated by the schematic (Fig. 6). First, the CNTP/TiO2 barrier physically blocks the diffusion of lithium polysulfides to the lithium anode. Thus, it could restrict the in-situ transformation of active materials to lithium polysulfides on the cathode surface, and also block existing lithium polysulfides from reacting with the lithium anode. The CNTP/TiO2 barrier also functions as a second current collector during the charge/discharge process. The positively charged TiO2 on the CNTP attracts the negatively charged polysulfide anions by electrostatic adsorption. The interaction between Lewis-acidic Ti (IV) centers and the basic polysulfides attracts the escaped lithium polysulfides. Most importantly, TiO2 chemically absorbs sulfur species by forming Ti–S and S–O bonds. Consequently, Li–S batteries with the multifunctional CNTP/TiO2 barrier display a long life and improved performance.