Abstract Driven by increasing demand for high-energy-density batteries for consumer electronics and electric vehicles, substantial progress is achieved in the development of long-life lithium–sulfur (Li–S) batteries. Less attention is given to Li–S batteries with high volume energy density, which is crucial for applications in compact space. Here, a series of elastic sandwich-structured cathode materials consisting of alternating VS2-attached reduced graphene oxide (rGO) sheets and active sulfur layers are reported. Due to the high polarity and conductivity of VS2, a small amount of VS2 can suppress the shuttle effect of polysulfides and improve the redox kinetics of sulfur species in the whole sulfur layer. Sandwich-structured rGO–VS2/S composites exhibit significantly improved electrochemical performance, with high discharge capacities, low polarization, and excellent cycling stability compared with their bare rGO/S counterparts. Impressively, the tap density of rGO–VS2/S with 89 wt% sulfur loading is 1.84 g cm−3, which is almost three times higher than that of rGO/S with the same sulfur content (0.63 g cm−3), and the volumetric specific capacity of the whole cell is as high as 1182.1 mA h cm−3, comparable with the state-of-the-art reported for energy storage devices, demonstrating the potential for application of these composites in long-life and high-energy-density Li–S batteries. The elastic sandwich-type composites of alternating reduced graphene oxide (rGO)–vanadium disulfide (VS2) sheets and pure sulfur layers are fabricated using conductive VS2 as a shape-directed agent. The rGO–VS2/S with an 89 wt% sulfur loading shows high tap density and striking volumetric specific capacity. The excellent electrochemical performance holds great potential for practical application in compact space.
Published in: "Advanced Energy Materials".