Lithium–sulfur batteries (LSBs) have high energy density and low cost, but their lifespan is shortened by the shuttle effect of sulfur species (lithium polysulfides, LiPSs), restricting their applications. Herein, a novel composite material consisting of Ru nanoclusters with an average diameter of approximately 3.51 nm, embedded in microporous carbon nanospheres (Ru@NC), is facilely synthesized to combat the shuttle effect and improve sulfur’s redox kinetics. Experimental and theoretical studies show that the Ru@NC features a durable spherical structure with abundant exposed active interfaces, high porosity, and a dual lithiophilic and thiophilic Ru–N structure, enabling efficient restriction of LiPSs and facilitating rapid electron and ion transfer. As a result, the battery shows good rate capability and retains a capacity of over 1050 mAh g–1 at 0.5 C after the rate performance test. Moreover, the Ru@NC/S cathode in the LSB exhibits excellent stability, offering a capacity of over 728 mAh g–1 after 800 cycles at a 1 C rate with nearly 100% Coulombic efficiency. Even under an S loading of 5.0 mg cm–2, the Ru@NC/S-based Li–S pouch cell achieves a capacity of 1097 mAh g–1, retaining 536 mAh g–1 after 100 cycles at a current density of 0.5 C.
Wang et al. (Mon,) studied this question.