Pt nanoclusters confined in the pores of hollow carbon spheres boost adsorption and electrochemical redox reaction for lithium-sulfur batteries

[Display omitted] •Small-sized Pt nanoclusters (PtNC) are synthesized and confined in the pores of HCS.•PtNC reveals excellent adsorption and catalytic ability while fixing S.•PtNC accelerates the transformation of polysulfides, and inhibit the shuttle effect.•PtNC@HCS as a host for Li-S cell cathode shows superior electrochemical performance. Sulfur (S) cathode is considered an ideal energy storage material for secondary batteries due to the high specific capacity and energy density. However, the insulating nature of S and lithium sulfide and slow electrochemical reaction kinetics, among many other issues, limit its power and energy output. Precious metals are vigorous catalytic materials and have been applied in various fields. However, the investigation of small-sized precious metal nanoclusters as the catalytic for polysulfide conversion in lithium-sulfur (Li-S) batteries has yet to be deepened. Herein, small-sized Pt nanoclusters are successfully synthesized and confined in the pores of hollow carbon spheres as the host for Li-S batteries cathode. The resultant PtNC@HCS provides the space for storing S and the electron transport network. Meanwhile, the Pt nanoclusters in the pores serve as catalytic sites for adsorbing and accelerating polysulfide conversion, thus effectively suppressing the shuttle effect. As a result, PtNC@HCS exhibits an initial capacity of 1460 mAh g−1 and a reversible capacity of 1316 mAh g−1 at 0.2C, with outstanding capacity retention, which confirms that such precious metal nanocluster catalytic material design effectively can optimize the electrochemical performance of Li-S batteries.