SO 3 -COF@Al 2 O 3 modified cathode electrode materials enhance the cycling ability of lithium sulfur batteries.

Herein, a covalent organic framework (SO 3 -COF) containing sulfonic acid groups has been developed on the surface of alumina by a one-step method, labeled as SO 3 -COF@Al 2 O 3 . The experimental results show that SO 3 -COF@Al 2 O 3 can effectively inhibit the shuttle effect of soluble lithium polysulfide (LiPSs) in LSBs after loading the active material sulfur, and exhibits better cycling behavior than the initial polymer SO 3 -COF. The initial discharge specific capacity of this electrode material at 0.05C is as high as 1141 mA h g -1 , and the capacity can be maintained at 466 mA h g -1 after 500 cycles with a capacity decay rate of 0.08% per cycle.