Effect of Ti 3 C 2 T x -PEDOT:PSS modified-separators on the electrochemical performance of Li-S batteries.

Lithium-sulfur (Li-S) batteries have attracted much attention due to their high theoretical energy density, environmental friendliness, and low cost. However, the practical application of Li-S batteries is impeded by a severe shuttle effect. Using polar and conductive materials to prepare a modified separator as the second collector is an effective strategy to solve the shuttle effect. Herein, a Ti 3 C 2 T x -PEDOT:PSS hybrid for modifying PP separators is successfully fabricated. In this hybrid, PEDOT:PSS can effectively prevent Ti 3 C 2 T x nanosheets from restacking and enhance the electrical conductivity of Li-S batteries, thereby promoting fast Li + /electron transport and improving the sulfur utilization. Meanwhile, the introduction of Ti 3 C 2 T x -PEDOT:PSS makes Ti 3 C 2 T x nanosheets effectively anchor polysulfide, thus inhibiting the shuttle effect. As a result, Li-S cells with Ti 3 C 2 T x -PEDOT:PSS modified-separators exhibit superior performances, including a high discharge capacity of 1241.4 mA h g -1 at 0.2C, a long cycling stability, and a low decay rate of 0.030% per cycle at 0.5C for 1000 cycles.