SO3-COF@Al2O3 modified cathode electrode materials enhance the cycling ability of lithium sulfur batteries

Abstract

Herein, a covalent organic framework (SO₃-COF) containing sulfonic acid groups has been developed on the surface of alumina by a one-step method, labeled as SO₃-COF@Al₂O₃. The experimental results show that SO₃-COF@Al₂O₃ 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 SO₃-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.