Anchoring Mo2C nanoparticles on vertical graphene nanosheets as a highly efficient catalytic interlayer for Li-S batteries

In order to accelerate the interconversion between sulfur and lithium polysulfides and suppress the shuttle effect for lithium-sulfur battery system, a multifunctional interlayer is prepared by anchoring Mo2C nanoparticles on vertical graphene nanosheets (VGSs) grown on short carbon nanofibers (CNFs), which is supported on carbon cloth decorated with VGSs (CG-CFG@Mo2C). In our strategy, Mo2C serves as a highly efficient electrocatalyst to expedite the reaction kinetics, while the interlaced framework constructed with VGSs grown on short carbon nanofibers (CFG) provides abundant conductive pathways for charge transfer. As a result, the Li-S batteries with CG-CFG@Mo2C interlayer show an ultra-high initial specific discharge capacity of 1632 mAh & BULL;g(-1), reaching a high sulfur utilization rate of 97.4%. Remarkable rate performance with a capacity of 755 mAh & BULL;gNi(3)S(2) at a current density of 3C (1C = 1675 mA & BULL;gNi(3)S(2)) is delivered. Under lean electrolyte dosage of 6 mu L & BULL;mgNi(3)S(2) with 4.4 mg & BULL;cm(-2) sulfur loading, the batteries achieve a high area capacity of 4.8 mAh & BULL;cm(-2). These results are more excellent than those batteries only with PP separator and demonstrate that the CG-CFG@Mo2C interlayer integrating high conductivity, physical barrier, and catalytic activity is of high application potential for high-performance Li-S batteries.