NiS2-MoS2 sandwich heterostructure with synergistic electron/ion transport for 10 C-rate Li-S batteries

Polysulfide shuttling and retarded electrode kinetics pose major obstacles to the practical application of lithium-sulfur (Li-S) batteries. Herein, a locally confined sandwich heterostructure composed of NiS 2 nanoparticles and 2H-MoS 2 nanosheets (NiS 2 -MoS 2 ) is designed as a cathode host material. Confined spaces formed by quasi-parallel MoS 2 nanosheets suppress the growth of NiS 2 nanocrystals through mass transport limitation and interfacial bonding, while the inner conductive NiS 2 particles act as spacers to prevent the restacking of MoS 2 nanosheets, constructing a three-dimensional network with open ion diffusion pathways. The sandwich structure offers extensive heterointerfaces. Interfacial charge transfer from Ni to Mo tailors the local electronic structure, yielding abundant catalytically active sites that accelerate polysulfide redox kinetics. The NiS 2 -MoS 2 @S cathode delivers an initial specific capacity of 1354 mAh g −1 at 0.3 C, retaining 1027 mAh g −1 after 200 cycles (capacity retention: 75.9%, average decay: 0.138%/cycle), and still outputs 517 mAh g −1 at an ultrahigh discharge rate of 10 C. Moreover, NiS 2 -MoS 2 @S pouch cell exhibits a specific capacity of 1214 mAh g −1 at 0.3 C and successfully powers a drone for a 9-min flight. This work offers novel perspectives for the rational engineering of advanced heterostructured host materials for Li–S batteries.