The design of eggshell-shaped S@FeS2/CoS2 heterojunction via less-liquid reaction strategy for magnesium/lithium-sulfur hybrid batteries

Magnesium/lithium-sulfur hybrid batteries (ML-SHBs) are considered to be the strongest candidate to replace lithium-ion batteries (LIBs) due to their high volumetric energy density and dendrite-free. In this study, S@FeS 2 /CoS 2 was prepared on the basis of a hollow, eggshell-shaped construction by using the less-liquid method. In this method, the reactants carry water of crystallization during the reaction to provide a liquid environment, and the metal ions on the surface of the droplets promote the formation of S@FeS 2 /CoS 2 . The configuration of the eggshell facilitates the generation of additional reaction interfaces, thereby expediting the interaction with the electrolyte and facilitating transport processes. This structure promotes efficient charge transfer and accelerates the transport rate. By implementing strategies such as heterostructure building and bimetallic doping, the controllable construction of the morphological structure can be realized. The induced effect of heterostructured interfaces can be excited within the nanocrystals to form an electric field, which effectively reduces the ion diffusion barrier and synchronously enhances the interfacial electron transfer efficiency by modulating the electronic behavior. The discharge specific capacity of the cell was found to be 1096.73 mAh g −1 at a current density of 200 mA g −1 , exhibiting a high rate capacity. The Coulombic efficiency remained at 99.8 % after 100 cycles at a current density of 500 mA g −1 .