No abstract

The serious shuttle effect of soluble polysulfides inevitably leads to low sulfur utilization and faster capacity decay, thus preventing the development of Li–S batteries. Array electrodes have attracted much attention owing to their binder-free and freestanding features. However, the insufficient surface area, lack of active sites with polysulfides, and poor conductive nature of the array electrode could not satisfy the need for high-rate and long-life Li–S batteries, especially for the high sulfur loading of Li–S batteries. Thus, in this work, we constructed the hierarchical C@SnO2/1T-MoS2 (C@SnO2@TMS) array electrode as the sulfur host. The hierarchical C@SnO2@TMS demonstrated strong adsorption with polysulfides, which could effectively facilitate polysulfide redox kinetics. With the C@SnO2@TMS/S as the electrode, the batteries achieved superb C-rate properties, high specific capacity, and ultralong lifespan. Even undergoing 4000 cycles at 5 C, the battery could retain a high specific capacity of 448 mAh g–1 with the capacity decay as low as 0.009% per cycle.

No abstract

To satisfy the demand of high power application, lithium-ion batteries (LIBs) with high power density have gained extensive research effort. The pseudocapacitive storage of LIBs is considered to offer high power density through fast faradic surface redox reactions rather than the slow diffusion-controlled intercalation process. In this work, CuCoS anchored on N/S-doped graphene is in situ synthesized and a typical pseudocapacitive storage behavior is demonstrated when applied in the LIB anode. The pseudocapacitive storage and N/S-doped graphene enable the composite to display a capacity of 453 mA h g after 500 cycles at 2 A g and a ultrahigh rate capability of 328 mA h g at 20 A g. We believe that this work could further promote the research on pseudocapacitive storage in transition-metal sulfides for LIBs.