Ferrocene-Derived Sulfur-Rich Cathode for High-Performance\nRechargeable Lithium Batteries

Abstract

Owing to abundant resources and low\ncost, organic compounds as\ncathode materials have shown unique advantages in lithium batteries.\nControl of structures could open a new chapter in designing the advanced\norganic cathode materials. Herein, we first report the synthesis of\nthe ferrocene sulfur-rich copolymer (Fc-S), where the ring opening\npolymerization of elemental sulfur takes place along the cyclopentenyl\nof ferrocene. The Fc-S copolymer exhibits the nanosphere in which\nthere is covalent binding between Fc and sulfur through the chemical\nand physical effects. The Fc skeleton can accommodate the 70 wt %\nsulfur to form the Fc-S nanocages (Fc-70S), which can effectively\nrelieve the huge volume change of sulfur during the charge/discharge\nprocess and ease dissolution and diffusion of polysulfides out of\ncathode. The Li/Fc-70S cell can display the initial discharge specific\ncapacity of 1037.4 mAh g^–1 and long cycle life for\n700 cycles with the retention of 55.1% at 0.2 C. As a result, this\nnovel Fc-S nanocomposite provides the approaches for the improvement\nof Li–S batteries and the development of advanced organic electrode\nmaterials.