Design of a La@Sn3O4/CeO2 heterostructure based on rare-earth element modification to enhance the polysulfide catalytic conversion rate of lithium-sulfur batteries

Currently, the obstacles to the feasibility of practical applications of lithium-sulfur batteries mainly come from the poor conductivity of the active sulfur material, the slow kinetics of the polysulfide reaction, and the severe shuttle effect. Considering these issues, in this paper, a multicomponent La@Sn 3 O 4 /CeO 2 heterostructure modified by rare-earth elements is constructed by a facile hydrothermal method to promote the catalytic conversion of LiPs and improve the cycling stability of the lithium-sulfur battery. In this heterostructure, the rare-earth La 3+ modified substrate has a defect-rich and highly active interface which provides a large number of reaction sites, while the Sn 3 O 4 -CeO 2 heterostructure interface has a strong interfacial electronic effect that accelerates the electron mobility and enhances the catalytic conversion efficiency to LiPs. In addition, the unique 4f5d electronic orbitals and variable valence states of the rare-earth elements effectively enhance the catalytic efficiency of the material for polysulfides, exhibiting efficient sulfur utilisation as well as good reaction kinetic rates, which are clearly confirmed by electrochemical test results and in situ Raman characterisation. As a result, the La@Sn 3 O 4 /CeO 2 /S heterostructure composite cathode exhibits excellent initial discharge capacity (up to 1560 mAh g −1 at 0.1 C) and good cycling stability (0.09 % decay rate over 500 cycles at 1 C), proving that the combination of rare-earth elements and multi-component electrocatalysts has a promising future for the application of lithium-sulfur batteries. • La@Sn 3 O 4 /CeO 2 heterogeneous modified by rare-earth elements is constructed as a cathode material for Li-S batteries. • The mechanism of the catalytic transformation of polysulfides is revealed by in-situ Raman tests. • 3.Defect engineering and heterogeneous interface are used to improve the catalytic efficiency. • The 4f5d electron orbitals and variable valence states of rare earth elements have strong interaction forces on LiPs.